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1
Madani, Seyed Saeed, Erik Schaltz, and Søren Knudsen Kær. "An Experimental Analysis of Entropic Coefficient of a Lithium Titanate Oxide Battery." Energies 12, no. 14 (July 12, 2019): 2685. http://dx.doi.org/10.3390/en12142685.
Повний текст джерелаАнотація:
In order to understand the thermal behaviour of a lithium-ion battery, the heat generation within the cell should be determined. The entropic heat coefficient is necessary to determine for the heat generation calculation. The entropic heat coefficient is one of the most important factors, which affects the magnitude of the reversible heat. The purpose of this research is to analyze and investigate the effect of different parameters on the entropic coefficient of lithium titanate oxide batteries. In this research, a lithium ion pouch cell was examined in both charging and discharging situations. The state of charge levels range was considered from 10% to 90%, and vice versa, in 10% increments. The temperature levels vary from 5 °C to 55 °C and the voltage levels vary from 1.5 V to 2.8 V. The effect of different parameters such as initial temperature, state of charge, thermal cycle, time duration for thermal cycles, and procedure prior to the thermal cycle on the entropic coefficient of lithium titanate oxide batteries were investigated. It was concluded that there is a strong influence of the battery cell state of charge on the entropic heat coefficient compared with other parameters.
2
Ning, Jing Hong, and Sheng Chun Liu. "Performance Experiment of Natural Refrigerant Cascaded Refrigeration System." Advanced Materials Research 383-390 (November 2011): 846–51. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.846.
Повний текст джерелаАнотація:
In this paper, the performances of natural refrigerant R290/CO2 cascaded refrigeration system using R290 as high temperature cycle refrigerant and CO2 as low temperature cycle refrigerant were investigated experimentally. The test results show that both CO2 compressor and R290 compressor start up stably and present good running performance. The start-up power and start-up electric current of CO2 compressor are higher than that of R290 compressor. The COP (Coefficient of performance) of R290/CO2 cascaded system enhances with the increase of cooling water mass flow rate and the decrease of cooling water inlet temperature. The effect of CO2 refrigerant charge on the COP of cascaded system is obvious; however, the effect of R290 refrigerant charge on the COP of cascaded system is not obvious. Hence, the hermetic scroll type compressor is urgent to be developed and used in CO2 cycle for ensuring run safely and reliably, the value of cooling water mass flow rate and the cooling water inlet temperature must be selected reasonability for saving water resource and energy, as well as the charge amount must be determined by experiment for obtaining the optimum refrigerant charge.
3
Xue, Qian, and Xijuan Chen. "Optimization of Planar Array Electrostatic Sensor for Metal Surface Defect Detection." Journal of Physics: Conference Series 2370, no. 1 (November 1, 2022): 012019. http://dx.doi.org/10.1088/1742-6596/2370/1/012019.
Повний текст джерелаАнотація:
Static electricity is usually generated in the damage area of the metal surface due to contact friction, and the charge distribution density can reflect the size, shape, and relative position of the damage area. Based on this, a planar array electrostatic sensor is designed to detect metal surface defect in this paper, and the shielding method, number of electrodes, electrode shape, and arrangement of the sensor are optimized taking account of the induced charge value, the uniformity of sensitivity and the image correlation coefficient. Different image reconstruction algorithms (e.g. Landweber algorithm, conjugate Gradient algorithm, Tikhonov regularization and primary dual interior point method) are utilized to evaluate the performance of the designed electrostatic sensor. The results demonstrated that the sensor with hexagonal electrode shape, integrated shielding, a new arrangement, a duty cycle of 80%, and a peripheral shielding electrode, has better image quality for all the tested damage models. When using the PDIPA algorithm for image reconstruction, the image correlation coefficient can exceed 0.9.
4
Xingcai, Lu, Ji Libin, Ma Junjun, and Huang Zhen. "Experimental study on the cycle-by-cycle variations of homogeneous charge compression ignition combustion using primary reference fuels and their mixtures." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 221, no. 7 (July 1, 2007): 859–66. http://dx.doi.org/10.1243/09544070jauto481.
Повний текст джерелаАнотація:
In this paper, the combustion stabilities and cycle-by-cycle variations of homogeneous charge compression ignition (HCCI) combustion using neat n-heptane, PRF20, PRF40, PRF50, and PRF60 were investigated. In-cylinder pressures of 100 combustion cycles for each test fuel on a single-cylinder engine were recorded. Consequently, cycle-to-cycle variations of the main combustion parameters and performance parameters were analysed, and the interdependency between the combustion parameter and performance parameters were also evaluated. The results reveal that the cycle-by-cycle variations deteriorate with the increase of the research octane number (RON). Especially, the coefficient of variations (COVs) of all parameters increase substantially when the RON of test fuels exceeds 40. For a certain test fuel, the COVs of combustion parameters that were used to depict the combustion characteristics during the early stage of combustion are very small, the COVs of combustion parameters that were used to describe the combustion characteristics of the post stage of the combustion are the largest, and the COVs of the i.m.e.p. and Pmax maintain at a middle level. Furthermore, a better interdependency also exists between the ignition timing of the low temperature reaction (LTR) and high temperature reaction (HTR), between the maximum pressure rise rate and its corresponding crank angle, between the peak values of the heat release and its corresponding crank angle.
5
Jeon, Min-Ju. "Experimental Analysis of the R744/R404A Cascade Refrigeration System with Internal Heat Exchanger. Part 1: Coefficient of Performance Characteristics." Energies 14, no. 18 (September 21, 2021): 6003. http://dx.doi.org/10.3390/en14186003.
Повний текст джерелаАнотація:
This study evaluates the performance of an R744/R404A cascade refrigeration system (CRS) with internal heat exchangers (IHE) in supermarkets. R744 is used as the refrigerant in a low-temperature cycle, and R404A is used as the refrigerant in a high-temperature cycle. In previous studies, there are many studies including theoretical performance analysis of the CRS. However, experimental studies on the CRS are lacking, and experimental research on the R744/R404A system with an IHE is scarce. Therefore, this study provides basic data for optimal refrigeration system design by experimentally evaluating the results of modifying various parameters. The operating parameters considered in this study include subcooling and superheating, condensing and evaporating temperature, cascade evaporation temperature, and IHE efficiency in the R744 low- and R404A high-temperature cycle. The main results are summarized as follows: (1) By applying the results of this study, energy efficiency is achieved by optimizing the overall coefficient of performance (COP) of the CRS, and the refrigerant charge of the R404A cycle is minimized and economic efficiency is also obtained, enabling operation and maintenance as an environment-friendly system. (2) When designing the CRS, finding the cascade evaporation temperature that has the optimum and maximum COP according to the refrigerant combination should be considered with the highest priority.
6
Tong, Xiangling, Junyuan Zhong, Xinxin Hu, and Fan Zhang. "Preparation and Performance of Highly Stable Cathode Material Ag2V4O11 for Aqueous Zinc-Ion Battery." Crystals 13, no. 4 (March 27, 2023): 565. http://dx.doi.org/10.3390/cryst13040565.
Повний текст джерелаАнотація:
One of the hottest research topics at present is the construction of environmentally friendly and secure aqueous zinc-ion batteries (AZIBs) using an aqueous electrolyte instead of an organic electrolyte. As a result of their diverse structure, valence state, high theoretical specific capacity, and other benefits, vanadium-based materials, which are frequently employed as the cathode of AZIBs, have drawn the attention of many researchers. The low cycle stability of zinc ion batteries (ZIBs) is mostly caused by the disintegration of the vanadium-based cathode materials during continuous charge and discharge. In this work, using 3M Zn(CF3SO3)2 as the electrolyte and hydrothermally synthesized Ag2V4O11 as the cathode material, the high-rate performance and extended cycle life of ZIBs were evaluated. The effects of different hydrothermal temperatures on the microstructure, capacity, and cycle stability of the Ag2V4O11 cathode material were examined. The experimental results show that Ag2V4O11 exhibits a typical intercalation-displacement process when used as the cathode material. The multiplicative performance and cycle stability of the cathode material were significantly enhanced at a hydrothermal temperature of 180 °C. Ag2V4O11-180 has a high discharge specific capacity of 251.5 mAh·g−1 at a current density of 0.5 A·g−1 and a long cycle life (117.6 mAh·g−1 after 1000 cycles at a current density of 3 A·g−1). According to the electrochemical kinetic investigation, the cathode material has a high pseudocapacitive charge storage and Zn2+ diffusion coefficient. This is attributed to the large layer spacing and the Ag+ anchored interlayer structure.
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Bramlage, Silke, and Klaus-Jürgen Wolter. "Effects of Vapor Phase Soldering on the Properties of Piezoceramic Materials." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (September 1, 2012): 000603–5. http://dx.doi.org/10.4071/cicmt-2012-tha24.
Повний текст джерелаАнотація:
Eight different PZT (lead zirconate titanate) materials (Navy Type I and II) with Curie temperatures between 250 °C and 350 °C were subjected to a standard vapor phase soldering process with a peak temperature of 240 °C for three cycles. As indicators for the depolarization, the piezoelectric charge coefficient (d33) and the coupling coefficient (keff) were measured both before and after each heat treatment. Our studies demonstrate reductions in piezoelectric properties between 5% and 20%, depending on the Curie temperature of the corresponding material. The effects of the second and third cycle were minimal. The drop in performance, especially for materials with higher Curie temperatures, is moderate, and can be accounted for in the design of the device. Thus batch soldering processes become a viable alternative to selective soldering.
8
Dannoun, Elham M. A., Shujahadeen B. Aziz, Sozan N. Abdullah, Muaffaq M. Nofal, Khaled H. Mahmoud, Ary R. Murad, Ranjdar M. Abdullah, and Mohd F. Z. Kadir. "Characteristics of Plasticized Lithium Ion Conducting Green Polymer Blend Electrolytes Based on CS: Dextran with High Energy Density and Specific Capacitance." Polymers 13, no. 21 (October 20, 2021): 3613. http://dx.doi.org/10.3390/polym13213613.
Повний текст джерелаАнотація:
The solution cast process is used to set up chitosan: dextran-based plasticized solid polymer electrolyte with high specific capacitance (228.62 F/g) at the 1st cycle. Fourier-transform infrared spectroscopy (FTIR) pattern revealed the interaction between polymers and electrolyte components. At ambient temperature, the highest conductive plasticized system (CDLG–3) achieves a maximum conductivity of 4.16 × 10−4 S cm−1. Using both FTIR and electrical impedance spectroscopy (EIS) methods, the mobility, number density, and diffusion coefficient of ions are measured, and they are found to rise as the amount of glycerol increases. Ions are the primary charge carriers, according to transference number measurement (TNM). According to linear sweep voltammetry (LSV), the CDLG–3 system’s electrochemical stability window is 2.2 V. In the preparation of electrical double layer capacitor devices, the CDLG–3 system was used. There are no Faradaic peaks on the cyclic voltammetry (CV) curve, which is virtually rectangular. Beyond the 20th cycle, the power density, energy density, and specific capacitance values from the galvanostatic charge–discharge are practically constant at 480 W/Kg, 8 Wh/Kg, and 60 F g−1, for 180 cycles.
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Saldaña, G., José Ignacio San Martín, F. J. Asensio, Inmaculada Zamora, O. Oñederra, M. González-Pérez, and I. J. Oleagordía. "Cycle-Life Curves Determination and Modelling of Commercially Available Electric Vehicle Batteries." Renewable Energy and Power Quality Journal 19 (September 2021): 287–92. http://dx.doi.org/10.24084/repqj19.278.
Повний текст джерелаАнотація:
In recent decades, there has been a growing concern about the trend of global emissions, and in particular those of the transport sector. In this context, the electric vehicle is a promising technology, with some barriers still to be overcome. Among these deficiencies everything related to storage technology is found. In this sense, lithium-ion batteries are one of the options to be considered, although it is necessary to continuously monitor the state of health. Cycle life vs DoD curves are very useful for characterizing profitability in any application that considers battery storage, as well as life cycle optimization studies. Cycle life refers to the number of charge-discharge cycles that a battery can provide before performance decreases to an extent that it cannot perform the required functions (e.g., 80% compared to a fresh one in electromobility applications). In this paper, a model for calculating the Cycle Life vs DoD curves is proposed, applied to a commercially available electric vehicle, the Renault Zoe. Modelling results show R squared coefficient of determinations above 0.9890.
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Rahim, Ahmad Syahmi Abdul, Mohd Zieauddin Kufian, Abdul Kariem Mohd Arof, and Zurina Osman. "Variation of Li Diffusion Coefficient during Delithiation of Spinel LiNi0.5Mn1.5O4." Journal of Electrochemical Science and Technology 13, no. 1 (February 28, 2022): 128–37. http://dx.doi.org/10.33961/jecst.2021.00780.
Повний текст джерелаАнотація:
For this study, the sol gel method was used to synthesize the spinel LiNi0.5Mn1.5O4 (LNMO) electrode material. Structural, morphological, electrochemical, and kinetic aspects of the LNMO have been characterized. The synthesized LNMO was indexed with the Fd3̄m cubic space group. The excellent capacity retention indicates that the spinel framework of LNMO has the ability to withstand high rate charge-discharge throughout long cycle tests. The Li diffusion coefficient (DLi) changes non-monotonically across three orders of magnitude, from 10−9 to 10−12 cm2 s−1 determined from GITT method. The variation of DLi seemed to be related to three oxidation reactions that happened throughout the charging process. A small dip in DLi at the beginning stage of Li deintercalation is correlated with the oxidation of Mn3+ to Mn4+. While two pronounced DLi minima at 4.7 V and 4.75 V are due to the oxidation of Ni2+/Ni3+ and Ni3+/Ni4+ respectively. The depletion of DLi at the high voltage region is attributed to the occurrence of two successive phase transformation phenomena.
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Konyukov, Vyacheslav Leontievich. "Influence of excessive air coefficient during combustion on intensity of two-stroke diesel engine operation in wide range of modes." Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2020, no. 3 (August 19, 2020): 54–63. http://dx.doi.org/10.24143/2073-1574-2020-3-54-63.
Повний текст джерелаАнотація:
The article describes the specific features of the forced diesel engines operating on a helical characteristic. One of them is a decreasing coefficient of excessive air during combustion with a decreasing power. Reducing the air charge of the cylinder and its available work require a greater cyclic supply of fuel to provide a given power, which affects the engine efficiency. It is possible to increase the boost pressure and the mass of the air charge of the cylinder by acting on the adjustable nozzle apparatus of a turbo-charging unit. In this case, gas parameters significantly change over the diesel cycle, which leads to changes in the indicators of thermal and mechanical tension. There have been presented the results of theoretical studies of indicators and criteria of thermal and mechanical tension of a marine two-stroke internal combustion engine operating in a wide range of modes with a constant coefficient of excessive air during combustion. Direct control of air flow at shared load modes was performed by turning the blades of an adjustable nozzle apparatus of a turbo-charging unit. The study of a diesel engine was carried out theoretically for two options: the original version (without adjustable nozzle unit) and under direct control of the air flow using an adjustable nozzle unit; the results were processed depending on the relative power of the diesel fractional load modes. There have been illustrated the graphs of dependence of the blade rotation angle of the nozzle apparatus of a turbocharging unit, relative change of the gas temperature behind the cylinder, cycle average temperature of the working fluid, average heat flux, relative change in the heat stress criterion of the piston, heat stress criterion for the cylinder, change in the pressure cycle of the working fluid, degree of increase working fluid during combustion, maximum rate of pressure rise depending on the load of the diesel engine.
12
Qi, Wanqiang. "Fuzzy control strategy of pure electric vehicle based on driving intention recognition." Journal of Intelligent & Fuzzy Systems 39, no. 4 (October 21, 2020): 5131–39. http://dx.doi.org/10.3233/jifs-179998.
Повний текст джерелаАнотація:
The main reason that currently hinders the commercialization of electric vehicles is a bottleneck in battery, motor and electronic control technology, however, an In-depth study of electronic control technology is one of the most effective means to break through this bottleneck at present. The purpose of this paper is to solve the problem that the pure electric vehicle is difficult to meet the driver’s acceleration intention in the urban road cycle acceleration work condition and the brake energy recovery process does not consider the battery state of charge during the deceleration work condition. Proposed a control strategy that can meet the requirements of road cycle conditions and driver’s driving intentions and take account of the vehicle operating status. Use a fuzzy control algorithm to develop a fuzzy controller that taking the motor demand speed change rate and battery state of charge as input, the motor demand torque compensation coefficient as output. The experimental results show that the modified control strategy can improve the actual output power, the actual output torque of the motor and actual driving force of the wheel under the premise of maintaining economy; it also improved the acceleration performance and climbing performance of pure electric vehicles, and can recycle braking energy efficiently. The experimental results show that the secondary development control strategy can meet the requirements of the cycle work condition CYC_ECE_EUDC for the speed and driving force and the driver’s driving intention under the premise of not sacrificing economics.
13
Fujii, Yuta, Hiroaki Ito, Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, and Li Lu. "Fast discharge–charge properties of FePS3 electrode for all-solid-state batteries using sulfide electrolytes and its stable diffusion path." Functional Materials Letters 14, no. 03 (March 18, 2021): 2141005. http://dx.doi.org/10.1142/s1793604721410058.
Повний текст джерелаАнотація:
We report the fast discharge–charge cycle of micro-sized FePS3 electrode particles in all-solid-state batteries (ASSBs) using sulfide electrolytes at 80∘C. At a current density of 2.04 mA cm[Formula: see text], corresponding to approximately 1 C, the capacity of the FePS3 electrodes reached [Formula: see text]180 mAh g[Formula: see text] without any electron or lithium-ion conductive additives. Galvanostatic intermittent titration technique (GITT) measurements showed a stable diffusion path of FePS3 represented by the product of the diffusion coefficient and square of the surface area. These electrochemical properties were compared with those of FeS, whose capacity was lower because of its unstable diffusion path.
14
Organ, A. J. "Two-Dimensional Thermodynamic and Flow Analysis of the Simple Hot-Air Engine." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 202, no. 1 (January 1988): 31–38. http://dx.doi.org/10.1243/pime_proc_1988_202_083_02.
Повний текст джерелаАнотація:
Attention focuses on the annular gap between displacer and cylinder shell as the gas passes between expansion and compression spaces. Equations are formulated for velocity and temperature distributions as a function of time and the distance coordinate directions—radial and axial. Local, instantaneous entropy creation rates due to viscous dissipation and heat transfer are computed without the need to refer to the usual friction factor and coefficient of convective heat transfer. From considerations of exergy an estimate of indicated thermodynamic work per cycle follows. This is expressed in terms of performance maps covering the entire range of possible speeds, charge pressures and sizes for a machine of given geometry.
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Shchegolkov, Alexander V., F. F. Komarov, M. S. Lipkin, O. V. Milchanin, I. D. Parfimovich, Aleksei V. Shchegolkov, A. V. Semenkova, A. V. Velichko, K. D. Chebotov, and V. A. Nokhaeva. "Synthesis and study of cathode materials based on carbon nanotubes for lithium-ion batteries." Perspektivnye Materialy 2 (2021): 66–76. http://dx.doi.org/10.30791/1028-978x-2021-2-66-76.
Повний текст джерелаАнотація:
This work presents a study of the conditions and possibilities for the intercalation of hexafluorophosphate anions into CNT-based electrodes. For this, cathodes based on CNTs synthesized on various (Co – Mo)/(Al2O3 – MgO) and (Fe – Co)/2.1Al2O3 catalysts were production. As a result, electrode materials were obtained at various concentrations of CNT/graphite: CNT-4F, CNT-6 and CNT-6F. The resulting electrodes were studied by cyclic voltammetry (CVA) in an electrolyte of a dissolved LiPF6 salt based on EC:DEC solvents (in the ratio 1: 1: 1) with an admixture of 3 % VC at a sweep speed of 4 mV/s. Based on the obtained CVA dependences, the specific charge/discharge capacity of the electrodes CNT-4F, CNT-6 and CNT-6F was determined. The largest specific charge/discharge capacity calculated on the mass of CNTs had CNT-4F/graphite electrodes 292 and 164.22 mA·h·g–1, and the minimum specific CNT-4 electrodes without graphite, 41.67 and 1.5 mA·h·g–1, respectively. Also, the dependences of the average electrode utilization coefficient on the charge time at constant current on the cycle number at a charge of 300 s were obtained. For chronoamperograms of individual steps of the СNT-6F electrode, the values of lithium diffusion coefficients were calculated.
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Okafor, Ekene G., Emmanuel Okafor, Osichinaka C. Ubadike, Paul O. Jemitola, Mohammed T. Abba, and Gowom Sule. "PERFORMANCE EVALUATION OF AN ELECTRIC VEHICLE INTEGRATED WITH REGENERATIVE BRAKING SYSTEM USING PI CONTROLLER." Journal of Southwest Jiaotong University 56, no. 4 (August 30, 2021): 697–708. http://dx.doi.org/10.35741/issn.0258-2724.56.4.59.
Повний текст джерелаАнотація:
Battery electric vehicles (BEVs) without regenerative braking mechanisms often suffer major drawbacks of limited driving range. Although extensive research works exist in electric vehicles integrated with regenerative braking, the performance evaluation of an electric ambulance, in the context of aerodynamic as well as energy recovery assessment from a complete vehicle modeling perspective based on the difference between the controlled dynamic speed and the drive cycle reference speed is not well reported. To compensate for the problem mentioned above, this paper aims to evaluate the performance of an electric ambulance (EA), integrated with a regenerative braking system (RBS) in comparison to an EA without a regenerative braking system (No RBS), in terms of aerodynamic drag coefficient values, state of charge (SOC), endurance efficiency, statistical correlation and mean absolute error (MAE) using proportional-integral (PI) controller. The SOLIDWORKS and SOLIDWORKS Flow Simulator were used to develop the EA CAD model and conduct aerodynamic analysis. MATLAB Simulink was used to model the EA complete EA system. The EA drive system was evaluated using three drive cycles (UDDS, FTP, and US06). The EA had an aerodynamic coefficient of 0.29. From the perspective of energy recycling, the EV-RBS yielded an extended drive range and appreciable gain in state of charge compared to EV-No RBS on the mentioned drive cycles. Generally, as the deceleration frequency increases from one drive cycle to another, the energy recycling increases, and the range increases correspondingly. In addition, the PI controller, which relied on speed error as a means of regulating the controlled speed, was found to be efficient, as the controlled speed was highly correlated to the reference speed. Overall, very low mean absolute errors in the vehicle speed were observed for the drive cycles considered.
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Okafor, Ekene G., Emmanuel Okafor, Osichinaka C. Ubadike, Paul O. Jemitola, Mohammed T. Abba, and Gowom Sule. "PERFORMANCE EVALUATION OF AN ELECTRIC VEHICLE INTEGRATED WITH REGENERATIVE BRAKING SYSTEM USING PI CONTROLLER." Journal of Southwest Jiaotong University 56, no. 4 (August 30, 2021): 697–708. http://dx.doi.org/10.35741/issn.0258-2724.56.4.59.
Повний текст джерелаАнотація:
Battery electric vehicles (BEVs) without regenerative braking mechanisms often suffer major drawbacks of limited driving range. Although extensive research works exist in electric vehicles integrated with regenerative braking, the performance evaluation of an electric ambulance, in the context of aerodynamic as well as energy recovery assessment from a complete vehicle modeling perspective based on the difference between the controlled dynamic speed and the drive cycle reference speed is not well reported. To compensate for the problem mentioned above, this paper aims to evaluate the performance of an electric ambulance (EA), integrated with a regenerative braking system (RBS) in comparison to an EA without a regenerative braking system (No RBS), in terms of aerodynamic drag coefficient values, state of charge (SOC), endurance efficiency, statistical correlation and mean absolute error (MAE) using proportional-integral (PI) controller. The SOLIDWORKS and SOLIDWORKS Flow Simulator were used to develop the EA CAD model and conduct aerodynamic analysis. MATLAB Simulink was used to model the EA complete EA system. The EA drive system was evaluated using three drive cycles (UDDS, FTP, and US06). The EA had an aerodynamic coefficient of 0.29. From the perspective of energy recycling, the EV-RBS yielded an extended drive range and appreciable gain in state of charge compared to EV-No RBS on the mentioned drive cycles. Generally, as the deceleration frequency increases from one drive cycle to another, the energy recycling increases, and the range increases correspondingly. In addition, the PI controller, which relied on speed error as a means of regulating the controlled speed, was found to be efficient, as the controlled speed was highly correlated to the reference speed. Overall, very low mean absolute errors in the vehicle speed were observed for the drive cycles considered.
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Krishnamoorthy, Umapathi, Parimala Gandhi Ayyavu, Hitesh Panchal, Dayana Shanmugam, Sukanya Balasubramani, Ali Jawad Al-rubaie, Ameer Al-khaykan, et al. "Efficient Battery Models for Performance Studies-Lithium Ion and Nickel Metal Hydride Battery." Batteries 9, no. 1 (January 12, 2023): 52. http://dx.doi.org/10.3390/batteries9010052.
Повний текст джерелаАнотація:
Apart from being emission-free, electric vehicles enjoy benefits such as low maintenance and operating costs, noise-free, easy to drive, and the convenience of charging at home. All these benefits are directly dependent on the performance of the battery used in the vehicle. In this paper, one-dimensional modeling of Li-ion and NiMH batteries was developed, and their performances were studied. The performance characteristics of the batteries, such as the charging and discharging characteristics, the constituent losses of over-potential voltage, and the electrolyte concentration profile at various stages of charge and discharge cycles, were also studied. It is found that the electrolyte concentration profiles of Li-ion batteries show a drooping behavior at the start of the discharge cycle and a rising behavior at the end of discharge because of the concentration polarization due to the low diffusion coefficient. The electrolyte concentration profiles of NiMH batteries show rising behavior throughout the discharge cycle without any deviations. The reason behind this even behavior throughout the discharge cycle is attributed to the reduced concentration polarization due to electrolyte transport limitations. It is found that the losses associated with the NiMH battery are larger and almost constant throughout the battery’s operation. Whereas for the Li-ion batteries, the losses are less variable. The electrolyte concentration directly affects the overpotential losses incurred during the charging and discharging phases.
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Brza, Mohamad, Shujahadeen Aziz, Hazleen Anuar, Saad Alshehri, Fathilah Ali, Tansir Ahamad, and Jihad Hadi. "Characteristics of a Plasticized PVA-Based Polymer Electrolyte Membrane and H+ Conductor for an Electrical Double-Layer Capacitor: Structural, Morphological, and Ion Transport Properties." Membranes 11, no. 4 (April 20, 2021): 296. http://dx.doi.org/10.3390/membranes11040296.
Повний текст джерелаАнотація:
Poly (vinyl alcohol) (PVA)-based solid polymer electrolytes doped with ammonium thiocyanate (NH4SCN) and glycerol were fabricated using a solution casting method. Lithium-based energy storage devices are not environmentally friendly materials, and they are toxic. Thus, proton-conducting materials were used in this work as they are harmless and are smaller than lithium. The interaction between PVA and the electrolyte elements was shown by FTIR analysis. The highest conductivity of 1.82 × 10−5 S cm−1 was obtained by the highest-conducting plasticized system (PSP_2) at room temperature. The mobility, diffusion coefficient, and number density of anions and cations were found to increase with increasing glycerol. FESEM was used to investigate the influence of glycerol on film morphology. TNM showed that the cations and anions were the main charge carriers. LSV showed that the electrochemical stability window of the PSP_2 system was 1.99 V. The PSP_2 system was applied in the preparation of an electrical double layer capacitor device. The shape of the cyclic voltammetry (CV) curve was nearly rectangular with no Faradaic peaks. From the galvanostatic charge-discharge analysis, the power density, energy density, and specific capacitance values were nearly constant beyond the first cycle at 318.73 W/Kg, 2.06 Wh/Kg, and 18.30 F g−1, respectively, for 450 cycles.
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Zhang, Daning, Guanwei Long, Yang Li, Haibao Mu, and Guanjun Zhang. "Effect of Radial Moisture Distribution on Frequency Domain Dielectric Response of Oil-Polymer Insulation Bushing." Polymers 12, no. 6 (May 27, 2020): 1219. http://dx.doi.org/10.3390/polym12061219.
Повний текст джерелаАнотація:
In order to realize the diagnosis of water distribution, this paper analyzes the interface polarization and macroscopic space charge polarization mechanism when the water distribution is non-uniform. The experimental results of this paper and bushing show that when the moisture distribution is non-uniform, there is a significant loss peak in the tanδ-f curve. The loss peak shifts to higher frequencies as the non-uniformity coefficient increases. There are common intersection points between multiple tanδ-f curves. Further, this paper realizes the diagnosis of the location of moisture distribution through Frequency Domain Spectroscopy (FDS) testing of different voltages and different wiring methods based on the macroscopic space charge polarization. In the single-cycle FDS test, when the positive electrode is first added to the area with higher moisture content, the amplitude of the tanδ-f curve is smaller. The tanδ-f curves under different wiring methods constitute a “ring-shaped” loss peak. As the voltage increases, the peak value of the loss peak shifts to the lower frequency band. As the temperature increases, the peak value of the loss peak shifts to higher frequencies. Based on the above rules and mechanism analysis, this research provides a new solution for the evaluation of moisture content of oil-immersed polymers equipment.
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Zhou, Peng, Shiran Luo, Xinzhou Li, Yitong Tan, Guangyu Cao, Cheng Li, Jilei Ye, Aiqiang Pan, Qiangqiang Liao, and Xiu Yang. "The Effects of Cycling Rates and Cycling Temperature on the Battery Degradation in Vehicle-to-Grid Applications." Science of Advanced Materials 12, no. 8 (August 1, 2020): 1205–12. http://dx.doi.org/10.1166/sam.2020.3755.
Повний текст джерелаАнотація:
Commercial LiFePO4/graphite batteries produced by A123 Systems were cycled by simulating urban drive modes and vehicle-to-grid (V2G) modes at the 1 C and 2 C V2G discharge rates under 25 °C and 45 °C environmental temperature. Their degeneration was explored by characterization of capacity attenuation, electrochemical impedance spectroscopy (EIS), charge/discharge test of two half cells, BET Surface Area, XRD, FE-SEM and EDS. Results show that the capacity declines obviously with the rise of V2G discharge rates and environmental temperature. With the progress of the cycle test, the ohmic resistance (Rs) doesn't change a lot before the first 900 cycles and rises a great deal during the second 900 cycles while the resistance of charge transfer (Rct) is relatively low and the diffusion coefficient of lithium ion (DLi +) climbs up and then declines. Moreover, the rise of temperature and discharge rates mainly results in the increase of Rs. The degradation of battery separator arisen from the rise of V2G discharge rates and environmental temperature is one of reasons that the battery performance was reduced. The ascend of temperature makes a more negative influence on the attenuation of anodes than that of cathodes while the rise of V2G discharge rates has similar negative influence on the degradation of cathodes and anodes.
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Hribernik, Ales, and John J. Moskwa. "Transient Response of a Cross-Flow Charge Air Intercooler and Its Influence on Engine Operation." Journal of Dynamic Systems, Measurement, and Control 122, no. 3 (June 16, 1998): 483–89. http://dx.doi.org/10.1115/1.1286683.
Повний текст джерелаАнотація:
To examine the influence of intercooler thermal inertia on transient engine operation, a 2D model of an air-to-air, cross-flow heat exchanger has been developed. Finned passages of heat exchanger core have been subdivided into separate channels of charge and cooling air, respectively. A two-step Lax-Wendroff differential method has been used to solve one-dimensional, nonhomentropic, unsteady, compressible fluid flow in each channel. Simultaneously, the Saul’yev explicit method has been applied to compute the 2D temperature distribution along the dividing plate. The Wieting correlation has been used to compute the local convection heat transfer coefficient and friction factor. The model has been verified against steady-state experimental data and then incorporated into an engine cycle simulation program based on “Filling-Emptying” method. Two engine transients have been simulated; the acceleration of the engine from idle to rated engine speed at constant load, and deceleration from rated power to rated torque by increasing the load torque. The first example shows the warming up of the intercooler, while in the second example intercooler temperatures are decreasing. The results have been compared with the predictions of an additional set of simulations, where the NTU-effectiveness method has been used to simulate the intercooler, and the thermal inertia of intercooler has been neglected. The results of both sets of simulations are discussed in the paper. [S0022-0434(00)02003-7]
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Moon, Jung Hyeon, Hyeonmuk Kang, GyuSeong Hwang, Junho Lee, GeunHyeong Shin, and EunAe Cho. "Li2So4 Coating of Co-Free, Li-Rich Layered Oxide Cathodes through a Carbonate Coating Method for Improving Cycle Performance." ECS Meeting Abstracts MA2023-01, no. 55 (August 28, 2023): 2671. http://dx.doi.org/10.1149/ma2023-01552671mtgabs.
Повний текст джерелаАнотація:
In the continued evolution toward high-performance lithium-ion batteries, cobalt has presented itself as a major obstacle due to its price and accessibility. Thus, Co-Free, Li-rich Layered Oxide Cathodes (CF-LLC) have become a promising cathode candidate for their exclusion of Cobalt and high theoretical capacity. Nevertheless, CF-LLC suffers from LLC issues such as phase transformation and voltage fade. Due to high overpotential from sluggish kinetics, the oxygen plateau of CF-LLC occurs at a higher-than-normal potential, leading to a shortened first cycle charge and lower discharge capacity. To mitigate this, we implemented a sulfate coating of the carbonate precursor; which upon lithiation, presents a Li2SO4 coated LLC (S-CF-LLC). The Li-sulfate coating prevents agglomeration of the primary particles during lithiation, leading to a larger surface area and thus, faster kinetics. The coating also prevents increased degradation from the increased surface area by acting as a protective barrier. The S-CF-LLC was successfully synthesized using a hydrothermal synthesis method with a wet chemical coating step and the synthesis was confirmed using XRD, SEM, XPS, and HR-TEM techniques. Galvanostatic cycling showed that the first cycle improved from 236.1mAhg-1 to 263.5mAhg-1 after coating, owing to the improved kinetics. GITT analysis of the increased diffusion coefficient further confirmed the overall improved kinetics. Moreover, the efficacy of the coating was shown through cycle data after 100 cycles, which showed good coulombic efficiency with a high average of >99%, good capacity retention, and good voltage fade per cycle improvement. Overall, the successfully synthesized S-CF-LLC opens up the possibility of practical cobalt-free high-performance batteries.
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Zhao, Yu, Zhaogang Qi, Jiangping Chen, Baixing Xu, and Bin He. "Experimental analysis of the low-GWP refrigerant R1234yf as a drop-in replacement for R134a in a typical mobile air conditioning system." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 226, no. 11 (January 16, 2012): 2713–25. http://dx.doi.org/10.1177/0954406211435583.
Повний текст джерелаАнотація:
This study investigated the performance of a typical mobile air conditioning system using R134a and R1234yf as the working fluids under different working conditions. The system is composed of a microchannel parallel flow condenser, a laminated plate evaporator, a variable displacement compressor, and a thermal expansion valve. The different working cycles of each refrigerant were comprehensively compared. The optimum refrigerant charge amount of the R1234yf system was approximately 95% of the R134a system during drop-in tests. The performance of the R134a system was a little higher than that of the R1234yf system. The cooling capacity and system coefficient of performance of the R134a system were 12.4% and 9% larger, respectively. This result is mainly because of the thermophysical property differences between the two refrigerants and the improper expansion valve opening of R1234yf. Analysis on the whole cycle revealed that the R1234yf system could obtain a higher evaporating pressure and a larger superheat and subcooling. Redesigning the expansion valve for R1234yf could improve performance of the system.
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Yu, Shijin, Wenzhen Zhu, Ying Wei, Jiahao Tong, Quanya Wei, Tianrui Chen, Xuannan He, Dingwen Hu, Cuiyun Li, and Hua Zhu. "Facile Synthesis of Multi-Channel Surface-Modified Amorphous Iron Oxide Nanospheres as High-Performance Anode Materials for Lithium-Ion Batteries." Energies 15, no. 16 (August 18, 2022): 5974. http://dx.doi.org/10.3390/en15165974.
Повний текст джерелаАнотація:
Based on the synergistic effect of ripening and hydrogen ion etching in a hydrothermal solution, a simple, facile, and low-cost new strategy was demonstrated to prepare multi-channel surface-modified amorphous Fe2O3 nanospheres as anodes for Li-ion batteries in this study. Compared with polycrystalline Fe2O3, the conversion reaction between amorphous Fe2O3 and lithium ions has a lower Gibbs free energy change and a stronger reversibility, which can contribute to an elevation in the cycle capability of the electrode. Meanwhile, there are abundant active sites and more effective dangling bonds/defects in amorphous materials, which is beneficial to promote charge transfer and lithium-ion migration kinetics. The Galvanostatic intermittent titration analysis results confirmed that the amorphous Fe2O3 electrode had a higher Li+ diffusion coefficient. In addition, the surfaces of the amorphous nanospheres are corroded to produce multiple criss-cross channels. The multi-channel surface structure can not only increase the contact area between Fe2O3 nanospheres and electrolyte, but also reserve space for volume expansion, thereby effectively alleviating the volume change during the intercalation-deintercalation of lithium ions. The electrochemical performance showed that the multi-channel surface-modified amorphous Fe2O3 electrode exhibited a higher specific capacity, a more stable cycle performance, and a narrower voltage hysteresis. It is believed that amorphous metal oxides have great potential as high-performance anodes of next-generation lithium-ion batteries.
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Zhang, Dong Yun, Li Zhang, Pei Xin Zhang, Mu Chong Lin, Xiao Qian Huang, Xiang Zhong Ren, and Qi Ming Xu. "Modification of LiFePo4 by Citric Acid Coating and Nb5+ Doping." Advanced Materials Research 158 (November 2010): 167–73. http://dx.doi.org/10.4028/www.scientific.net/amr.158.167.
Повний текст джерелаАнотація:
In order to improve the electrochemical performance of LiFePO4, Li0.99Nb0.01FePO4/C composite materials were synthesized with citric acid coating and Nb2O5 doping. The physical chemistry and electrochemical performances of Li0.99Nb0.01FePO4/C were investigated by X-Ray diffraction (XRD) and Transmission electron microscope (TEM). The results show that Li0.99Nb0.01FePO4/C has smooth charge-discharge voltage platform, with first capacity of 151.6 mAh•g-1 (0.1C) and no obvious capacity fading after 16 cycles. The materials have favorable high rate discharge performances, with the first capacity of 131.6 mAh•g-1 at 0.5C, 119.8 mAh•g-1 at 1.0C and 106.2 mAh•g-1 at 2.0C. Equivalent circuits analysis shows that the impedance, especially electrode reaction resistance of Li0.99Nb0.01FePO4/C are significantly reduced compared with the pure LiFePO4 and this helps to improve the electric conductivity, discharge capacity and cycle performance. The diffusion coefficient of Li+ in Li0.99Nb0.01FePO4/C is 2.51×10-12 cm2•s-1 increased two orders of magnitude in comparison with the pure LiFePO4. Carbon-coating makes a more remarkable contribution to lithium diffusion than Nb5+ ion doping.
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Lee, Jun-Seok, Sang-Du Yun, Oyunbayar Nyamaa, Jeong-Hyeon Yang, Sun-Chul Huh, Hyo-Min Jeong, Tae-Hyun Nam, Yeon-Ju Ryu, and Jung-Pil Noh. "Free-Standing Li4Ti5O12/Carbon Nanotube Electrodes for Flexible Lithium-Ion Batteries." Energies 15, no. 22 (November 16, 2022): 8585. http://dx.doi.org/10.3390/en15228585.
Повний текст джерелаАнотація:
Lithium-ion batteries (LIBs) have been used in many fields, such as consumer electronics and automotive and grid storage, and its applications continue to expand. Several studies have attempted to improve the performance of LIBs. In particular, the use of high-capacity silicon and tin as anodes has been widely studied. Although anodes composed of silicone and tin have high theoretical capacities, poor electrical conductivity and considerable volume expansion of such anodes deteriorate the LIB performance. Thus, Li4Ti5O12 (LTO), a zero-strain material, has attracted much attention with high cycle stability and rate capability through improved electrical conductivity. However, LTO has the disadvantages of a low electrical conductivity (10−8 to 10−13 S cm−1) and moderate Li+ ion diffusion coefficient (10−9 to 10−16 cm2 s−1). In this study, the flexible and free-standing composite films were fabricated using only LTO and multi-walled carbon nanotube(CNT) with high electrical conductivity and ion diffusivity. The prepared LTO/CNT films showed a higher charge/discharge capacity than the theoretical capacity of the LTO electrode.
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Meng, Xiangdong, Wei Wang, Xinyu Cao, Gang Li, and Dexing Li. "A RUL Prediction Method of Lithium-ion Battery Based on Extreme Learning Machine." Journal of Physics: Conference Series 2492, no. 1 (May 1, 2023): 012026. http://dx.doi.org/10.1088/1742-6596/2492/1/012026.
Повний текст джерелаАнотація:
Abstract Owing to the complexity of the electrochemical reaction types in lithium-ion batteries and the characteristics of nonlinear degradation, using physical models to describe the degradation process is often not accurate enough. This paper only analyzes from the perspective of data, through a data-driven method, extreme learning machine ( ELM ), to predict the remaining useful life (RUL) of lithium-ion. Firstly, the cycle charge and discharge data of lithium-ion battery are analyzed in depth to find the parameters which can indirectly characterize the degree of degeneracy of lithium-ion battery. The parameters with strong robustness to the actual capacity of lithium-ion battery are selected as indirect health indicators by correlation coefficient analysis. Then, the RUL prediction model based on ELM is constructed, which is trained and tested using the lithium-ion battery data sample set published by NASA. The results show that the RUL prediction method based on ELM can effectively predict the battery RUL, and the root mean square error (RMSE) can reach below 5 %.
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Muggeridge, David Joseph, Kirsty Hickson, Aimie Victoria Davies, Oonagh M. Giggins, Ian L. Megson, Trish Gorely, and Daniel R. Crabtree. "Measurement of Heart Rate Using the Polar OH1 and Fitbit Charge 3 Wearable Devices in Healthy Adults During Light, Moderate, Vigorous, and Sprint-Based Exercise: Validation Study." JMIR mHealth and uHealth 9, no. 3 (March 25, 2021): e25313. http://dx.doi.org/10.2196/25313.
Повний текст джерелаАнотація:
Background Accurate, continuous heart rate measurements are important for health assessment, physical activity, and sporting performance, and the integration of heart rate measurements into wearable devices has extended its accessibility. Although the use of photoplethysmography technology is not new, the available data relating to the validity of measurement are limited, and the range of activities being performed is often restricted to one exercise domain and/or limited intensities. Objective The primary objective of this study was to assess the validity of the Polar OH1 and Fitbit Charge 3 devices for measuring heart rate during rest, light, moderate, vigorous, and sprint-type exercise. Methods A total of 20 healthy adults (9 female; height: mean 1.73 [SD 0.1] m; body mass: mean 71.6 [SD 11.0] kg; and age: mean 40 [SD 10] years) volunteered and provided written informed consent to participate in the study consisting of 2 trials. Trial 1 was split into 3 components: 15-minute sedentary activities, 10-minute cycling on a bicycle ergometer, and incremental exercise test to exhaustion on a motorized treadmill (18-42 minutes). Trial 2 was split into 2 components: 4 × 15-second maximal sprints on a cycle ergometer and 4 × 30- to 50-m sprints on a nonmotorized resistance treadmill. Data from the 3 devices were time-aligned, and the validity of Polar OH1 and Fitbit Charge 3 was assessed against Polar H10 (criterion device). Validity was evaluated using the Bland and Altman analysis, Pearson moment correlation coefficient, and mean absolute percentage error. Results Overall, there was a very good correlation between the Polar OH1 and Polar H10 devices (r=0.95), with a mean bias of −1 beats·min-1 and limits of agreement of −20 to 19 beats·min-1. The Fitbit Charge 3 device underestimated heart rate by 7 beats·min-1 compared with Polar H10, with a limit of agreement of −46 to 33 beats·min-1 and poor correlation (r=0.8). The mean absolute percentage error for both devices was deemed acceptable (<5%). Polar OH1 performed well across each phase of trial 1; however, validity was worse for trial 2 activities. Fitbit Charge 3 performed well only during rest and nonsprint-based treadmill activities. Conclusions Compared with our criterion device, Polar OH1 was accurate at assessing heart rate, but the accuracy of Fitbit Charge 3 was generally poor. Polar OH1 performed worse during trial 2 compared with the activities in trial 1, and the validity of the Fitbit Charge 3 device was particularly poor during our cycling exercises.
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Уханов, Александр, Aleksandr Ukhanov, Денис Уханов, Denis Ukhanov, Евгений Сидоров, Evgeniy Sidorov, Александр Якунин, and Aleksandr Yakunin. "FEATURES OF THE DIESEL RUNNING BY CAMELINA-MINERAL FUEL IN THE MODE OF INDEPENDENT IDLING." Bulletin Samara State Agricultural Academy 2, no. 3 (July 27, 2017): 15–19. http://dx.doi.org/10.12737/17446.
Повний текст джерелаАнотація:
The mode of independent idling, characterized by an impaired process flow, unproductive fuel consumption and increased emissions of harmful substances into the atmosphere, is the most unfavorable mode of the diesel engine operation. Therefore, the aim of the research is to reveal the peculiarities of the tractor diesel engine operation by the camelina-mineral fuel in the mode of independent idling. Camelina-mineral fuel is a mixture of camelina oil and mineral diesel fuel in certain ratio of these components. To assess the possibility of using the camelina oil as biological component of diesel mixed fuel, an experimental study of the D-243 diesel engine in idling mode was carried out, and the degree of influence of the different ratio of the components of the mixed fuel on its parameters was determined. The researches were carried out with the diesel fuel on the L-0.2-62 mineral fuel and the camelina-mineral fuel with a ratio of the biological and mineral components: 25% RyzhM + 75% DT; 50% RyzhM + 50% DT; 75% RyzhM + 25% DT; 90% RyzhM + 10% DT and 90% RyzhM + 10% DT (US). For the parameters of the diesel, the excess air factor, the filling ratio of the diesel cylinder with fresh charge, the maximum cycle pressure, the hourly fuel consumption, smoke and carbon monoxide content in the exhaust gases are taken. It is established that when the diesel engine works on camelina-mineral fuel mode the minimum sustainable speed of the crankshaft idle speed 800 min-1 the values of maximum cycle pressure (6.3 MPa) and the filling ratio of the cylinders of a diesel engine the fresh charge (0,87) remain unchanged. The coefficient of excess air, increasing in mixed fuel shares of camelina oil to 90%, reduced from 7.187 to 4.619, while fuel consumption increases of 1.1 kg/h 2 kg/h. The best environmental indicators are observed when working on red-and-mineral fuel 50% RyzhM + 50% DT. Handling mixed fuel with ultrasound reduces fuel consumption, smoke and content of carbon oxide in the exhaust gas relative to the mixed fuel not treated with ultrasound.
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Geng, Cong, Dawen Ning, Linfu Guo, Qicheng Xue, and Shujian Mei. "Simulation Research on Regenerative Braking Control Strategy of Hybrid Electric Vehicle." Energies 14, no. 8 (April 15, 2021): 2202. http://dx.doi.org/10.3390/en14082202.
Повний текст джерелаАнотація:
This paper proposes a double layered multi parameters braking energy recovery control strategy for Hybrid Electric Vehicle, which can combine the mechanical brake system with the motor brake system in the braking process to achieve higher energy utilization efficiency and at the same time ensure that the vehicle has sufficient braking performance and safety performance. The first layer of the control strategy proposed in this paper aims to improve the braking force distribution coefficient of the front axle. On the basis of following the principle of braking force distribution, the braking force of the front axle and the rear axle is reasonably distributed according to the braking strength. The second layer is to obtain the proportional coefficient of regenerative braking, considering the influence of vehicle speed, braking strength, and power battery state of charge (SOC) on the front axle mechanical braking force and motor braking force distribution, and a three-input single-output fuzzy controller is designed to realize the coordinated control of mechanical braking force and motor braking force of the front axle. Finally, the AMESim and Matlab/Simulink co-simulation model was built; the braking energy recovery control strategy proposed in this paper was simulated and analyzed based on standard cycle conditions (the NEDC and WLTC), and the simulation results were compared with regenerative braking control strategies A and B. The research results show that the braking energy recovery rate of the proposed control strategy is respectively 2.42%, 18.08% and 2.56%, 16.91% higher than that of the control strategies A and B, which significantly improves the energy recovery efficiency of the vehicle.
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Zhuang, Ruiyuan, Shanshan Yao, Maoxiang Jing, Xiangqian Shen, Jun Xiang, Tianbao Li, Kesong Xiao, and Shibiao Qin. "Synthesis and characterization of electrospun molybdenum dioxide–carbon nanofibers as sulfur matrix additives for rechargeable lithium–sulfur battery applications." Beilstein Journal of Nanotechnology 9 (January 24, 2018): 262–70. http://dx.doi.org/10.3762/bjnano.9.28.
Повний текст джерелаАнотація:
One-dimensional molybdenum dioxide–carbon nanofibers (MoO2–CNFs) were prepared using an electrospinning technique followed by calcination, using sol–gel precursors and polyacrylonitrile (PAN) as a processing aid. The resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Brunauer–Emmet–Teller (BET) surface area measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). MoO2–CNFs with an average diameter of 425–575 nm obtained after heat treatment were used as a matrix to prepare sulfur/MoO2–CNF cathodes for lithium–sulfur (Li–S) batteries. The polysulfide adsorption and electrochemical performance tests demonstrated that MoO2–CNFs did not only act as polysulfide reservoirs to alleviate the shuttle effect, but also improve the electrochemical reaction kinetics during the charge–discharge processes. The effect of MoO2–CNF heat treatment on the cycle performance of sulfur/MoO2–CNFs electrodes was examined, and the data showed that MoO2–CNFs calcined at 850 °C delivered optimal performance with an initial capacity of 1095 mAh g−1 and 860 mAh g−1 after 50 cycles. The results demonstrated that sulfur/MoO2–CNF composites display a remarkably high lithium–ion diffusion coefficient, low interfacial resistance and much better electrochemical performance than pristine sulfur cathodes.
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Sheelam, Anjaiah, Dalton Lee Glasco, and Jeffrey Gordon Bell. "Lorentz-Force-Mediated Zn Electrodeposition and Br- Ion Convection for Improved Performance in Aqueous Zn-Br2 Static Batteries." ECS Meeting Abstracts MA2022-01, no. 1 (July 7, 2022): 17. http://dx.doi.org/10.1149/ma2022-01117mtgabs.
Повний текст джерелаАнотація:
Redox flow batteries are one of the prominent electrochemical energy storage devices with large-scale storage and high energy density.1 The highly reversible Zn/Zn2+ (-0.76 V vs. RHE) and Br-/Br2 (1.08 V vs. RHE) redox couple have been employed in Zn-Br2 flow batteries (1.84 V vs. RHE). However, the dendritic growth of Zn electrodeposits during the repetitive discharge process triggers an internal short-circuit between the anode and the cathode.1 Besides this, cross-diffusion of the highly soluble Br- (Br3 -) ion causes a severe self-discharge of the system and reduced cycle life.2 Additives and ion-selective membranes have been employed to mitigate these challenges for improved cycle life and coulombic efficiency in Zn-Br2 batteries.3 Here, we fabricate an aqueous Zn-Br2 static battery with internally contained and moderate magnetic fields, (~ 30, 40, 50 and 60 mT) at the anode and cathode by incorporating 1 mm thick Nd permanent magnets. A solid complex of tetrapropylammonium tribromide was supported on activated carbon and employed as the positive electrode. Introducing a magnetic field can generate the Lorentz force (acting on Br- and Zn2+ ions), and create a controllable magnetohydrodynamic mass transport during the charge-discharge processes. Among the various magnetic fields, ~50 mT resulted in the highest coulombic efficiency (99 % for 100 cycles) and suppressed Zn dendritic growth. To rationalize the effect of magnetic fields on the efficiency and cycle life, Raman analysis, X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry (for the calculation of diffusion coefficient of Br- ion) are performed on the positive and negative electrodes of Zn-Br2 battery. References: (1) Z. Yuan, X. Liu, W. Xu, Y. Duan, H. Zhang, X. Li, Nat. Commun., 9 , 3731 (2018). (2) L. Gao, Z. Li, Y. Zou, S. Yin, P. Peng, Y. Shao, X. Liang, iScience, 23, 101348 (2020). (3) E. Sánchez-Díez, E. Ventosa, M. Guarnieri, A. Trovò, C. Flox, R. Marcilla, F. Soavi, P. Mazur, E. Aranzabe, R. Ferret, J . Power Sources, 481, 228804 (2021).
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James Abraham, Jeffin, Buzaina Moossa, Hanan Abdurehman Tariq, Ramazan Kahraman, Siham Al-Qaradawi, and R. A. Shakoor. "Electrochemical Performance of Na3V2(PO4)2F3 Electrode Material in a Symmetric Cell." International Journal of Molecular Sciences 22, no. 21 (November 7, 2021): 12045. http://dx.doi.org/10.3390/ijms222112045.
Повний текст джерелаАнотація:
A NASICON-based Na3V2(PO4)2F3 (NVPF) cathode material is reported herein as a potential symmetric cell electrode material. The symmetric cell was active from 0 to 3.5 V and showed a capacity of 85 mAh/g at 0.1 C. With cycling, the NVPF symmetric cell showed a very long and stable cycle life, having a capacity retention of 61% after 1000 cycles at 1 C. The diffusion coefficient calculated from cyclic voltammetry (CV) and the galvanostatic intermittent titration technique (GITT) was found to be ~10−9–10−11, suggesting a smooth diffusion of Na+ in the NVPF symmetric cell. The electrochemical impedance spectroscopy (EIS) carried out during cycling showed increases in bulk resistance, solid electrolyte interphase (SEI) resistance, and charge transfer resistance with the number of cycles, explaining the origin of capacity fade in the NVPF symmetric cell. Finally, the postmortem analysis of the symmetric cell after 1000 cycles at a 1 C rate indicated that the intercalation/de-intercalation of sodium into/from the host structure occurred without any major structural destabilization in both the cathode and anode. However, there was slight distortion in the cathode structure observed, which resulted in capacity loss of the symmetric cell. The promising electrochemical performance of NVPF in the symmetric cell makes it attractive for developing long-life and cost-effective batteries.
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Ложкина, Д. А., Е. В. Астрова та А. М. Румянцев. "Зависимость электрохимических параметров композитных SiO/C-анодов для литий-ионных аккумуляторов от состава и температуры синтеза". Журнал технической физики 92, № 3 (2022): 421. http://dx.doi.org/10.21883/jtf.2022.03.52137.267-21.
Повний текст джерелаАнотація:
The results of a study of anodes obtained by carbonization of silicon monoxide by means of a reaction with solid-phase fluorocarbon CF0.8 are presented. Charge/discharge voltage profiles were studied at different currents depending on the composition and temperature of the synthesis of composites. The irreversible losses of the 1st cycle and the contribution to them of intrinsic losses due to the formation of lithium oxide and its silicates and losses associated with the formation of SEI are analyzed. A difference has been established in the behavior of anodes made of SiO carbonized by annealing with CF0.8 at T=800°C (SiO/C composite) and silicon monoxide annealed with CF0.8 at T>1000°C, at which disproportionation occurs simultaneously with the carbonization of SiO (d-SiO/C composite). The difference consisting in a higher discharge capacity, a higher Coulomb efficiency, and better rate capability of d-SiO/C is explained by a change in the composition of the SiOx matrix that occurs during the disproportionation process. The effect of the formation of d-SiO/C anodes by preliminary lithiation with a low current, after which the electrodes can be charged and discharged with much higher currents, has been discovered. The effect is explained by the amorphization of silicon crystallites and the increasing diffusion coefficient of lithium
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Lozhkina D.A., Astrova E.V., and Rumyantsev A.M. "Dependence of the electrochemical parameters of composite SiO/C anodes for lithium-ion batteries on the composition and synthesis temperature." Technical Physics 92, no. 3 (2022): 339. http://dx.doi.org/10.21883/tp.2022.03.53264.267-21.
Повний текст джерелаАнотація:
The results of a study of anodes obtained by carbonization of silicon monoxide by means of a reaction with solid-phase fluorocarbon CF0.8 are presented. Charge/discharge voltage profiles were studied at different currents depending on the composition and temperature of the synthesis of composites. The irreversible losses of the 1st cycle and the contribution to them of intrinsic losses due to the formation of lithium oxide and its silicates and losses associated with the formation of SEI are analyzed. A difference has been established in the behavior of anodes made of SiO carbonized by annealing with CF0.8 at T=800oC (SiO/C composite) and silicon monoxide annealed with CF0.8 at T>1000oC at which disproportionation occurs simultaneously with the carbonization of SiO (d-SiO/C composite). The difference consisting in a higher discharge capacity, a higher Coulomb efficiency, and better rate capability of d-SiO/C is explained by a change in the composition of the SiOx matrix that occurs during the disproportionation process. The effect of the formation of d-SiO/C anodes by preliminary lithiation with a low current, after which the electrodes can be charged and discharged with much higher currents, has been discovered. The effect is explained by the amorphization of silicon crystallites and the increasing diffusion coefficient of lithium. Keywords: composite anodes SiO/C, lithium-ion batteries, disproportionation silicon monoxide, carbonization with fluorocarbon.
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Yudhiyantoro, Prihangkasa. "Implementation of Fuzzy Logic Control on Battery Charging System." ACMIT Proceedings 3, no. 1 (March 18, 2019): 118–26. http://dx.doi.org/10.33555/acmit.v3i1.34.
Повний текст джерелаАнотація:
This paper presents the implementation fuzzy logic control on the battery charging system. To control the charging process is a complex system due to the exponential relationship between the charging voltage, charging current and the charging time. The effective of charging process controller is needed to maintain the charging process. Because if the charging process cannot under control, it can reduce the cycle life of the battery and it can damage the battery as well. In order to get charging control effectively, the Fuzzy Logic Control (FLC) for a Valve Regulated Lead-Acid Battery (VRLA) Charger is being embedded in the charging system unit. One of the advantages of using FLC beside the PID controller is the fact that, we don’t need a mathematical model and several parameters of coefficient charge and discharge to software implementation in this complex system. The research is started by the hardware development where the charging method and the combination of the battery charging system itself to prepare, then the study of the fuzzy logic controller in the relation of the charging control, and the determination of the parameter for the charging unit will be carefully investigated. Through the experimental result and from the expert knowledge, that is very helpful for tuning of the embership function and the rule base of the fuzzy controller.
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Chevreuil, M., A. Chesterikoff, and R. Létolle. "Modalités du transport des PCB dans la rivière Seine (France)." Revue des sciences de l'eau 1, no. 4 (April 12, 2005): 321–37. http://dx.doi.org/10.7202/705015ar.
Повний текст джерелаАнотація:
L'évolution de la pollution et les modalités du transport des P.C.B. en rivière ont été étudiées en Seine à Paris en relation avec les épisodes du cycle hydrologique durant un an. Les résultats analytiques montrent que la pollution occasionnée par les P.C.B. est supérieure à celle produite par les autres résidus de pesticides organochlorés, et ceci malgré la limitation réglementaire d'emploi des P.C.B. aux systèmes clos depuis 1975. Pour 88 % des échantillons analysés, les concentrations en P.C.B. dissous sont supérieures aux teneurs en P.C.B. adsorbés sur M.E.S. et atteignent jusqu'à 170 ng.l-1. Le transport se fait en solution pour 73 %, en moyenne, de la teneur totale, contrairement aux idées admises fondées sur la faible solubilité du polluant, mais qui ne prennent pas en compte le rapport en masse M.E.S./eau voisin de 25 x 10-6 en rivière. L'étude de la capacité d'adsorption des particules démontre qu'elle subit une évolution inverse de celle de la charge solide et du débit, ce qui explique la dominance des P.C.B. en phase aqueuse quelle que soit la teneur en M.E.S. Il en résulte que les valeurs élevées du coefficient de partage ne correspondent pas aux fortes teneurs en M.E.S. Les valeurs sont faibles pour la moitié d'entre elles et comprises entre 2 x 103 et 12 x 103 l.kg-1.
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Qi, Yue, Christine James, Tridip Das, Jason D. Nicholas, Leah Nation, and Brian W. Sheldon. "(Invited) Computing the Anisotropic Chemical Strain in Non-Stoichiometric Oxides for Solid Oxide Fuel Cell and Li-Ion Battery Applications." ECS Meeting Abstracts MA2018-01, no. 32 (April 13, 2018): 1940. http://dx.doi.org/10.1149/ma2018-01/32/1940.
Повний текст джерелаАнотація:
Accurate characterization of chemical strain is required to study a broad range of chemical-mechanical coupling phenomena. By combining density functional theory (DFT) calculations and elastic dipole tensor theory, it is readily to predict the long-range chemical strain tensor and the chemical expansion coefficient tensor induced by dilute point defects in a crystal structure. First, we demonstrate that, even in cubic CeO2-δ, both the short-range deformation surrounding an oxygen vacancy and the long-range chemical strain (or the expansion coefficient) are anisotropic. The origin of this anisotropy is the charge disproportionation between the four cerium atoms surrounding each oxygen vacancy (two become Ce3+ and two become Ce4+) when a neutral oxygen vacancy is formed. While the short-range deformation agrees with experimentally determined Ce-O bond lengths, the predicted maximum and average chemical strains successfully bound the variety of CeO2-δ chemical strain behavior previously reported in the literature. Normally, since there are six possible disproportionation configurations, the average chemical strain is isotropic. Only under an external bias, such as an applied electric field, the chemical strain can be oriented to show the anisotropic effect. This successfully explained the giant electrostriction effect reported in doped and un-doped CeO2-δ. Next, we show strains induced by coupled vacancies in layered Li-intercalation compounds for battery applications. Li2MnO3 was investigated as Li-excess intercalation compounds containing Li2MnO3 need to be “activated” to deliver the high capacity. This activation process during the first delithiation cycle at a high voltage is believed to introduce oxygen vacancies into the system. Due to the large amount Li vacancy generated, a large number of defect configurations were sampled and the average chemical strain induced by Li vacancy concentration is obtained by Boltzmann average. Previously, we have demonstrated that it is energetically favorable to create a Li-O-Li vacancy dumbbell structure (VLi - VO - VLi) in Li2MnO3. The chemical strain of the vacancy dumbbell structure is smaller than the sum of the chemical strain of one Vo and two VLis. The chemical expansion coefficient averaged for the polycrystalline samples and the experimentally measured stress change provided a novel method to in situ track the irreversible chemical changes in Li-excess cathode materials.
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Kimmich, G. A., J. Randles, and E. Bennett. "Sodium-dependent succinate transport by isolated chick intestinal cells." American Journal of Physiology-Cell Physiology 260, no. 6 (June 1, 1991): C1151—C1157. http://dx.doi.org/10.1152/ajpcell.1991.260.6.c1151.
Повний текст джерелаАнотація:
Isolated chick intestinal epithelial cells take up succinate by a Na(+)-coupled transport system similar in some characteristics to those described for renal epithelium. The transport system exhibits a hyperbolic dependence on succinate concentration but a sigmoidal dependence on Na+ concentration. Best nonlinear fit of the Na+ dependence data to the Hill equation indicates a Michaelis constant for half-maximal transport rate (Km) for Na+ of approximately 20 mM, a maximal transport rate (Vmax) of 1.1 nmol succinate.min-1.mg protein-1, and a Hill coefficient of 2.5. Nearly equivalent fit was obtained with trial Hill coefficients down to 2.0. The data for succinate dependence indicated a Km of 25 microM and Vmax of 1.05 nmol.min-1.mg protein-1. The kinetic parameters indicate a higher affinity, lower capacity system than for succinate transport in the renal brush-border system. Thiocyanate-induced diffusion potentials cause no change in Na(+)-dependent succinate influx despite pronounced effects on the influx of tetraphenylphosphonium and on Na(+)-dependent alpha-methylglucoside (AMG) and alanine uptake. Several other dicarboxylic and tricarboxylic metabolic intermediates (but not the dicarboxylic amino acids) compete with succinate for uptake via the transport system. The data are consistent with the likelihood that these cells have a succinate transport system with a 2Na+:1succinate stoichiometry per transport cycle. The system catalyzes no net charge transfer and is therefore different from the potential-responsive succinate transporter described for renal tissue.
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Zheng, Feng, Qiang Zhen, Sajid Bashir, and Jingbo Louise Liu. "(Digital Presentation) Ternary Metal Oxide Electrodes Used in Supercapacitor to Improve Emerging Energy Storage." ECS Meeting Abstracts MA2022-01, no. 38 (July 7, 2022): 1685. http://dx.doi.org/10.1149/ma2022-01381685mtgabs.
Повний текст джерелаАнотація:
Supercapacitors with improved specific capacitance (F g-1), long cycling life, high power (W kg-1), and energy densities (Whkg-1) were fabricated to close the gap between traditional and emerging energy storage materials. We developed responsive supercapacitor electrodes with heterojunctions composed of well-aligned vanadium (V) oxide (V2O5) ribbon arrays and manganese (IV) oxide (MnO2) nanoparticles sphere-network structure. The V2O5 arrays were deposited on the nickel foam substrate using a cost-effective and green hydrothermal chemistry, followed by a MnO2 nano-grafting. The architectural MnO2 modification successfully increased highly reactive interfaces with channels for efficient ion transport. Electrochemical evaluation of this ternary metal oxide system indicated that mesopores and macropores among the MnO2 generated channels that increased electron conduction and shortened ion diffusion pathways. The hybrid electrodes have demonstrated a specific capacitance as high as 788 F g−1 at 5 mV s-1, an improved cyclic steadiness averaged at 92.5 % after 5000 cycles. The charge transfer resistances of these electrodes were lowered to 4.6 Ω and the effective diffusion coefficient of Li+ was 7.90 × 10−9 cm2 s−1. The symmetrical supercapacitor device assembled by the hybrid electrode achieved a high energy density of 138 W h kg-1 at a power density of 450 W kg-1 was achieved and retained at 81.0 W h kg-1 at 9000 W kg-1 after 5000 cycles. The advances in designing nanostructured supercapacitor electrode materials based on these heterojunction arrays enhanced the properties of supercapacitors including specific capacitance, energy density, and cycle stability. Figure 1
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Sarkozy, Daniel, and Andras Guttman. "Capillary Sodium Dodecyl Sulfate Agarose Gel Electrophoresis of Proteins." Gels 8, no. 2 (January 19, 2022): 67. http://dx.doi.org/10.3390/gels8020067.
Повний текст джерелаАнотація:
Capillary sodium dodecyl sulfate gel electrophoresis has long been used for the analysis of proteins, mostly either with entangled polymer networks or translationally cross-linked gels. In this paper capillary agarose gel electrophoresis is introduced for the separation of low molecular weight immunoglobulin subunits. The light (LC~24 kDa) and heavy (HC~50 kDa) chain fragments of a monoclonal antibody therapeutic drug were used to optimize the sieving matrix composition of the agarose/Tris-borate-EDTA (TBE) systems. The agarose and boric acid contents were systematically varied between 0.2–1.0% and 320–640 mM, respectively. The influence of several physical parameters such as viscosity and electroosmotic flow were also investigated, the latter to shed light on its effect on the electrokinetic injection bias. Three dimensional Ferguson plots were utilized to better understand the sieving performance of the various agarose/TBE ratio gels, especially relying on their slope (retardation coefficient, KR) value differences. The best resolution between the LC and non-glycosylated HC IgG subunits was obtained by utilizing the molecular sieving effect of the 1% agarose/320 mM boric acid composition (ΔKR = 0.035). On the other hand, the 0.8% agarose/640 mM boric acid gel showed the highest separation power between the similar molecular weight, but different surface charge density non-glycosylated HC and HC fragments (ΔKR = 0.005). It is important to note that the agarose-based gel-buffer systems did not require any capillary regeneration steps between runs other than simple replenishment of the sieving matrix, significantly speeding up analysis cycle time.
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Erdogmus, Fatma Nur, Melis Öder, Ahmet Berk Ezber, and Oktay Kalkan. "Investigation of Cooling Systems Faults, Control and Management Models." Orclever Proceedings of Research and Development 2, no. 1 (March 28, 2023): 68–80. http://dx.doi.org/10.56038/oprd.v2i1.250.
Повний текст джерелаАнотація:
With the rapid increase in population in the world, people's demands for chilled and frozen foods are also increasing. The healthy and energy efficient cold storage of foods has become an important issue. In this context, studies on the efficiency and performance of energy management models including automatic control techniques on cooling systems have been investigated in recent years. The purpose of this study is to give information about faults, traceable energy management models and control systems in the perspective of cooling systems.
Maintenance of cooling systems, malfunctions and their late detection cause time and cost problems. The decrease in the performance of the cooling system or the occurrence of malfunctions cause economic costs as well as energy consumption. Controlling the changes in pressure, temperature and electricity consumption values in cooling systems and comparing them with standard operating conditions is one of the methods used for fault detection. Faults that may occur in cooling systems; compressor, condenser, evaporator, expansion element and fan failures, thermal failures, phase protection relay failures, under/over refrigerant charge, probe failures, night curtain electric motor failure, condenser-evaporator surface pollution. Errors and malfunctions occurring in the cycle cause the parameters under normal operating conditions and accordingly the cooling performance coefficient to change. Traceable energy management models are needed to detect faults and prevent them in a short time. With the design and implementation of these models, long-term damage to the system is prevented by reducing energy, maintenance and repair costs.
In the design of traceable energy management models and control systems for cooling systems; set point and management, alarm notification and management, designing algorithms with precise temperature control will provide energy efficiency.
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Moritomo, Yutaka. "(Keynote, Digital Presentation) Prussian Blue Analogues as Electrode Material of Batteries." ECS Meeting Abstracts MA2022-02, no. 59 (October 9, 2022): 2201. http://dx.doi.org/10.1149/ma2022-02592201mtgabs.
Повний текст джерелаАнотація:
Prussian blue analogues (PBA), which composed of cyano-bridged jungle-gym type framework and alkali metal ions, are promising material for electrode of batteries, because its framework is robust against electrochemical intercalation/deintercalation of alkali metal ions. In addition, the material consists of ubiquitous elements and is easily synthesized from aqueous solution. Thus, PBAs are promising electrode material for sodium ion secondary battery (SIB). We will introduce the overall features of PBAs as SIB electrode. Furthermore, PBAs are promising material for energy harvesting. We proposed a new type of battery (tertiary battery) that can be charged by the environmental heat using the difference in the thermal coefficient (α= dV/dT) of the redox potential (V) between the anode (αanode) and cathode (αcathode) materials. The tertiary battery can convert the environmental heat energy into electric energy during the thermal cycle, i.e., (i) heating to TH, (ii) discharge at TH, (iii) cooling to TL, and (iv) discharge at TL. In the (i) heating process, the V values of the anode and cathode change by αanodeΔTand αcathodeΔT, respectively. We expect a thermally induced change in the cell voltage (V cell) as large as (αcathode - αanode)ΔT. The stored electric energy can be extracted by the (ii) discharge process at TH. We fabricated several tertiary batteries made of PBA electrodes with different a and evaluated the thermal voltage (Vcell) and discharge capacity (Qcell). For example, NaxCo[Fe(CN)6]0.87/NaxNi[Fe(CN)6]0.94 tertiary battery exhibits Vcell = 24 mV and Qcell = 2.4 mAh/g per unit weight of total active material contains in the cathode and anode. We will correlate the observed Qcell values with the electrode parameters of the tertiary batteries. Y. Shimaura, T. Shibata, and Y. Moritomo, "Interrelation between discharge capacity and charge coefficient of redox potential in tertiary batteries made of transition metal hexacyanoferrate", Jpn. J. Appl. Phys. 61, 044004 (2022) I. Nagai, Y. Shimaura, T. Shibata, and Y. Moritomo, "Performance of tertiary battery made of Prussian blue analogues", Appl, Phys. Express. 14, 094004 (2021). Y. Moritomo, Y. Yoshida, D. Inoue, H. Iwaizumi, S. Kobayashi, S. Kawaguchi, and T. Shibata "Origin of the material dependence of the temperature coefficient of the redox potential in coordination polymers", J. Phys. Soc. Jpn. 90, 063801 (2021). T. Shibata, H. Iwaizumi, Y. Fukuzumi, and Y. Moritomo, "Energy harvesting thermocell with use of phase transition” Sci. Res., 10 1813 (2020) I. Takahara, T. Shibata, Y. Fukuzumi, and Y. Moritomo, " Improved thermal cyclability of tertiary battery made of Prussian blue analogues ", Chem. Select 4, 8558-8563 (2019) Y. Fukuzumi, K. Amaha, W. Kobayashi, H. Niwa, and Y. Moritomo, “Prussian blue analogues as promising thermal power generation materials”, Energy Technology, 6 (2018) 1 – 7. T. Shibata, Y. Fukuzumi, W. Kobayashi, and Y. Moritomo, “Thermal efficiency of a thermocell made of Prussian blue analogues”, Sci. Reps. Appl. Phys. Express. 8 (2018) 14784. T. Shibata, Y. Fukuzumi, W. Kobayashi, and Y. Moritomo, Thermal power generation during heat cycle near room temperature, Appl. Phys. Express. 11, 018101 (2018). M. Takachi, T. Matsuda, and Y. Moritomo, “Cobalt hexacyanoferrate as cathode material of Na+ secondary battery”, Appl. Phys. Express 6, 025802 (2013). M. Takachi, T. Matsuda, and Y. Moritomo, “Redox reaction in Prussian blue analogues with fast Na+ intercalation”, Jpn. J. Appl. Phys. 52, 092202 (2013).
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Liu, Xixue, Datong Qin, and Shaoqian Wang. "Minimum Energy Management Strategy of Equivalent Fuel Consumption of Hybrid Electric Vehicle Based on Improved Global Optimization Equivalent Factor." Energies 12, no. 11 (May 30, 2019): 2076. http://dx.doi.org/10.3390/en12112076.
Повний текст джерелаАнотація:
A parallel hybrid electric vehicle (PHEV) is used to investigate the fuel economy effect of the equivalent fuel consumption minimization strategy (ECMS) with the equivalent factor as the core, where the equivalent factor is the conversion coefficient between fuel thermal energy and electric energy. In the conventional ECMS strategy, the battery cannot continue to discharge when the state of charge (SOC) is lower than the target value. At this time, the motor mainly works in the battery charging mode, making it difficult to adjust the engine operating point to the high-efficiency zone during the acceleration process. To address this problem, a relationship model of the battery SOC, vehicle acceleration a, and equivalent factor S was established. When the battery SOC is lower than the target value and the vehicle demand torque is high, which makes the engine operating point deviate from the high-efficiency zone, the time that the motor spends in the power generation mode during the driving process is reduced. This enables the motor to drive the vehicle at the appropriate time to reduce the engine output torque, and helps the engine operate in the high-efficiency zone. The correction function under US06 condition was optimized by genetic algorithm (GA). The best equivalent factor MAP was obtained with acceleration a and battery SOC as independent variables, and the improved global optimal equivalent factor of ECMS was established and simulated offline. Simulation results show that compared with conventional ECMS, the battery still has positive power output even when the SOC is less than the target value. The SOC is close to the target value after the cycle condition, and fuel economy improved by 1.88%; compared with the rule-based energy management control strategies, fuel economy improved by 10.17%. These results indicate the effectiveness of the proposed energy management strategy.
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Maroteaux, Fadila, Ezio Mancaruso, and Bianca Maria Vaglieco. "Optical and Numerical Investigations on Combustion and OH Radical Behavior Inside an Optical Engine Operating in LTC Combustion Mode." Energies 16, no. 8 (April 14, 2023): 3459. http://dx.doi.org/10.3390/en16083459.
Повний текст джерелаАнотація:
Low Temperature Combustion (LTC) is a relevant process for internal combustion engines (ICE). This combustion mode is based on premixed fuel/air and fuel lean in-cylinder mixture allowing reduction in NOx and PM emissions while maintaining higher thermal efficiency. In order to investigate the effect of engine operating conditions on the behavior of LTC mode, including OH radical evolution, optical measurements and numerical simulations were performed on a transparent CR diesel engine. The homogeneity of the engine charge was obtained by using very early injection timings. In this study, varying injection strategies were investigated for different engine speeds. In parallel to the experimentation, simulations of LTC mode for the same experimental operations were carried out. The model used in this study is based on a stochastic reactor model. This model includes a turbulence (k-ε) model based on a zero-dimensional energy cascade to calculate the turbulent time scale during the cycle. On the other hand, due to the stochastic approach and to reduce initial heterogeneities of the mixture, a confidence parameter was introduced in the global model to consider the real variation ranges of engine. This latter was modeled as a function of the Reynolds number allowing to initiate heterogeneities of temperature and of species mass. OH radicals were estimated with high spatial and temporal resolution using chemiluminescence measurements. Simulated in-cylinder pressure and the OH radical rate were compared to the experimental data. A good agreement was observed in terms of in-cylinder pressure trace and ignition delay times, meaning that the confidence coefficient model is accurate to describe the initial heterogeneities of the mixture. The simulated OH rate profile has the same shape as the measured OH trace and the main ignition occurs at the same time. This study corroborates that the OH radical is an appropriate tool to identify combustion stages.
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Ma, Xiaotu, and Yan Wang. "(Digital Presentation) Recycled Cathode Materials Enabled Superior Performance for Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 5 (July 7, 2022): 594. http://dx.doi.org/10.1149/ma2022-015594mtgabs.
Повний текст джерелаАнотація:
With the widely equipped Lithium-ion batteries (LIBs) in electronics and electric vehicles, proper handle spent LIBs has been the subject of increasing concern. Significantly raised concerns about resource constraints and environmental issues are brought by spent LIBs. Therefore, properly handling spent LIBs is urgent and necessary.[1] However, until now, getting manufacturers to recruit recycled materials has been a hard sell because recycled materials are deemed as inferior to commercial materials, which limits the development of recycling. Although previous publications stated that their recovered materials had a comparable performance as commercial materials, the results, based on coin cells and low electrode loading, cannot convince manufacturers to employ recycled materials in the new LIBs.[2] Here, we demonstrate that recycled cathode materials with optimized microstructure have the best industrial relevant testing results (up to 11Ah cells) so far and compare them with state-of-the-art commercial equivalent. Interestingly, the recycled materials not only pass all the aggressive industrial plug-in hybrid electric vehicle (PHEV) battery tests, but also outperform control counterparts in some tests. Specifically, 1 Ah cells with the recycled LiNi1/3Mn1/3Co1/3O2 have the best cycle life result reported for recycled materials and enable 4,200 cycles and 11,600 cycles at 80% and 70% capacity retention, which is 33% and 53% better than the state-of-the-art, commercial LiNi1/3Mn1/3Co1/3O2. Meanwhile, its rate performance is 88.6% better than commercial powders at 5C. Through detailed experimental and modeling analysis of pristine and cycled materials, we discover that the unique porous and larger inside void microstructure enables the superior rate and cycle performance and less phase transformation. Compared with the control sample, the surface area of the recycled LiNi1/3Mn1/3Co1/3O2 is 82.14% larger and the cumulative pore volume is 61.25% larger. Even some recycled particles have an outer diameter of the void space equal to 40% to 60% of the particle diameter. The unique microstructure can reduce 16% hoop stress during the discharge/charge process compared to control materials, and improve the lithium chemical diffusion coefficient, enabling the superior performance of cycle life and rate performance and less phase transformation. The results pave the way to re-introduce recycled materials into new batteries.[3] [1] M. Chen, X. Ma, B. Chen, R. Arsenault, P. Karlson, N. Simon, Y. Wang, Recycling End-of-Life Electric Vehicle Lithium-Ion Batteries, Joule 2019, 3, 2622.10.1016/j.joule.2019.09.014 [2] X. Ma, L. Azhari, Y. Wang, Li-ion battery recycling challenges, Chem 2021.10.1016/j.chempr.2021.09.013 [3] X. Ma, M. Chen, Z. Zheng, D. Bullen, J. Wang, C. Harrison, E. Gratz, Y. Lin, Z. Yang, Y. Zhang, F. Wang, D. Robertson, S.-B. Son, I. Bloom, J. Wen, M. Ge, X. Xiao, W.-K. Lee, M. Tang, Q. Wang, J. Fu, Y. Zhang, B. C. Sousa, R. Arsenault, P. Karlson, N. Simon, Y. Wang, Recycled cathode materials enabled superior performance for lithium-ion batteries, Joule 2021.10.1016/j.joule.2021.09.005
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Baboraik, Abdulrahman, and Alexander Usachev. "New model of explanation for phase angle pattern of online partial discharge measurement in winding insulation of turbine generator." Journal of Electrical Engineering 72, no. 1 (February 1, 2021): 66–77. http://dx.doi.org/10.2478/jee-2021-0010.
Повний текст джерелаАнотація:
Abstract On-line partial discharge (PD) measurement in electrical insulation of the turbine generator (TG) is an essential approach to control the quality of insulation and to avoid any undesired shutdowns of TG. Although in the last few decades the number of research in PD on-line monitoring methods in the stator winding of TG has increased significantly, it is still not clear yet why PD only appears at certain phase angles of the AC cycle in the phase resolved partial discharge (PRPD) pattern. Moreover, there is not yet any clarification on how the winding configuration of stator may affect PD phase angle pattern. For this reason, this work examines detailed study of the impact of the winding diagram on PD occurrence in the stator winding of real turbine generator class TVF-60-2 (60 MW, 10.5 KV). In addition, a computer simulation of various sizes of ellipsoidal cavities from 0.1 to 2.5 mm between conductor bar and stator core were carried out by using Laplaces equation in Finite Element Analysis (FEA) software ComSol to investigate the relation between the cavity size and coefficient of electric field. As a result of that, the phase angle of PD occurrence in the stator winding will highly depend on the configuration of bars connection, and the computer simulation has helped identifying the PD inception voltage and applied voltage of various ellipsoidal defects size. These two results have helped proposing an initial new theoretical model of explanation the relationship between voltage distributions and phase angle of PD occurrence to determine the degradation level of insulation caused by ellipsoidal defects in the insulation bars of the stator winding which can be used for stator windings of TG rated 6 kV and higher. This model is the initial step to develop a further comprehensive model of explanation for PRPD patterns which will consider all other types of defects as well as the space charge effects from the previous PD.
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Dannoun, Elham M. A., Shujahadeen B. Aziz, Rebar T. Abdulwahid, Sameerah I. Al-Saeedi, Muaffaq M. Nofal, Niyaz M. Sadiq, and Jihad M. Hadi. "Study of MC:DN-Based Biopolymer Blend Electrolytes with Inserted Zn-Metal Complex for Energy Storage Devices with Improved Electrochemical Performance." Membranes 12, no. 8 (August 8, 2022): 769. http://dx.doi.org/10.3390/membranes12080769.
Повний текст джерелаАнотація:
Stable and ionic conducting electrolytes are needed to make supercapacitors more feasible, because liquid electrolytes have leakage problems and easily undergo solvent evaporation. Polymer-based electrolytes meet the criteria, yet they lack good efficiency due to limited segmental motion. Since metal complexes have crosslinking centers that can be coordinated with the polymer segments, they are regarded as an adequate method to improve the performance of the polymer-based electrolytes. To prepare plasticized proton conducting polymer composite (PPC), a simple and successful process was used. Using a solution casting process, methylcellulose and dextran were blended and impregnated with ammonium thiocyanate and zinc metal complex. A range of electrochemical techniques were used to analyze the PPC, including transference number measurement (TNM), linear sweep voltammetry (LSV), cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The ionic conductivity of the prepared system was found to be 3.59 × 10−3 S/cm using the EIS method. The use of glycerol plasticizer improves the transport characteristics, according to the findings. The carrier species is found to have ionic mobility of 5.77 × 10−5 cm2 V−1 s−1 and diffusion coefficient of 1.48 × 10−6 cm2 s−1 for the carrier density 3.4 × 1020 cm−3. The TNM revealed that anions and cations were the predominant carriers in electrolyte systems, with an ionic transference value of 0.972. The LSV approach demonstrated that, up to 2.05 V, the film was stable, which is sufficient for energy device applications. The prepared PPC was used to create an electrical double-layer capacitor (EDLC) device. The CV plot exhibited the absence of Faradaic peaks in the CV plot, making it practically have a rectangular form. Using the GCD experiment, the EDLC exhibited low equivalence series resistance of only 65 Ω at the first cycle. The average energy density, power density, and specific capacitance values were determined to be 15 Wh/kg, 350 W/kg, and 128 F/g, respectively.
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Sun, Binbin, Tiezhu Zhang, Wenqing Ge, Cao Tan, and Song Gao. "Driving energy management of front-and-rear-motor-drive electric vehicle based on hybrid radial basis function." Archives of Transport 49, no. 1 (March 31, 2019): 47–58. http://dx.doi.org/10.5604/01.3001.0013.2775.
Повний текст джерелаАнотація:
This paper presents mathematical methods to develop a high-efficiency and real-time driving energy management for a front-and-rear-motor-drive electric vehicle (FRMDEV), which is equipped with an induction motor (IM) and a permanent magnet synchronous motor (PMSM). First of all, in order to develop motor-loss models for energy optimization, database of with three factors, which are speed, torque and temperature, was created to characterize motor operation based on HALTON sequence method. The response surface model of motor loss, as the function of the motor-operation database, was developed with the use of Gauss radial basis function (RBF). The accuracy of the motor-loss model was verified according to statistical analysis. Then, in order to create a two-factor energy management strategy, the modification models of the torque required by driver (Td) and the torque distribution coefficient (β) were constructed based on the state of charge (SOC) of battery and the motor temperature, respectively. According to the motor-loss models, the fitness function for optimization was designed, where the influence of the non-work on system consumption was analyzed and calculated. The optimal β was confirmed with the use of the off-line particle swarm optimization (PSO). Moreover, to achieve both high accuracy and real-time performance under random vehicle operation, the predictive model of the optimal β was developed based on the hybrid RBF. The modeling and predictive accuracies of the predictive model were analyzed and verified. Finally, a hardware-in-loop (HIL) test platform was developed and the predictive model was tested. Test results show that, the developed predictive model of β based on hybrid RBF can achieve both real-time and economic performances, which is applicable to engineering application. More importantly, in comparison with the original torque distribution based on rule algorithm, the torque distribution based on hybrid RBF is able to reduce driving energy consumption by 9.51% under urban cycle.