Tesi sul tema "Flexible supercapacitors"
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YANG, YONGRUI. "Flexible Supercapacitors with Novel Gel Electrolytes". University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590682495188219.
Testo completoZhang, Ruirong. "A study of flexible supercapacitors : design, manufacture and testing". Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/13426.
Testo completoLorenzo, Fernandez Marta. "Flexible supercapacitors utilising the multifunctional rôle of ionic liquids". Thesis, Queen's University Belfast, 2018. https://pure.qub.ac.uk/portal/en/theses/flexible-supercapacitors-utilising-the-multifunctional-role-of-ionic-liquids(8645dbf6-5a8e-4f19-ba27-bbb6adb7c7e3).html.
Testo completoZACCAGNINI, PIETRO. "Graphene-based supercapacitors for flexible and harsh environments application". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2875757.
Testo completoAreir, Milad. "Development of 3D printed flexible supercapacitors : design, manufacturing, and testing". Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16659.
Testo completoSi, Wenping. "Designing Electrochemical Energy Storage Microdevices: Li-Ion Batteries and Flexible Supercapacitors". Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-160049.
Testo completoHuman beings are facing the grand energy challenge in the 21st century. Nowhere has this become more urgent than in the area of energy storage and conversion. Conventional energy is based on fossil fuels which are limited on the earth, and has caused extensive environmental pollutions. Additionally, the consumptions of energy are still increasing, especially with the rapid proliferation of vehicles and various consumer electronics like PCs and cell phones. We cannot rely on the earth’s limited legacy forever. Alternative energy resources should be developed before an energy crisis. The developments of renewable conversion energy from solar and wind are very important but these energies are often not even and continuous. Therefore, energy storage devices are of significant importance since they are the one stabilizing the converted energy. In addition, it is a disappointing fact that nowadays a smart phone, no matter of which brand, runs out of power in one day, and users have to carry an extra mobile power pack. Portable electronics demands urgently high-performance energy storage devices with higher energy density. The first part of this work involves lithium-ion micro-batteries utilizing single silicon rolled-up tubes as anodes, which are fabricated by the rolled-up nanotechnology approach. A lab-on-chip electrochemical device platform is presented for probing the electrochemical kinetics, electrical properties and lithium-driven structural changes of a single silicon rolled-up tube as an anode in lithium ion batteries. The second part introduces the new design and fabrication of on chip, all solid-state and flexible micro-supercapacitors based on MnOx/Au multilayers, which are compatible with current microelectronics. The micro-supercapacitor exhibits a maximum energy density of 1.75 mW h cm-3 and a maximum power density of 3.44 W cm-3. Furthermore, a flexible and weavable fiber-like supercapacitor is also demonstrated using Cu wire as substrate. This dissertation was written based on the research project supported by the International Research Training Group (IRTG) GRK 1215 "Rolled-up nanotech for on-chip energy storage" from the year 2010 to 2013 and PAKT project "Electrochemical energy storage in autonomous systems, no. 49004401" from 2013 to 2014. The aim of the projects was to design advanced energy storage materials for next-generation rechargeable batteries and flexible supercapacitors in order to address the energy issue. Here, I am deeply indebted to IRTG for giving me an opportunity to carry out the research project in Germany. September 2014, IFW Dresden, Germany Wenping Si
Zhang, Panpan, Faxing Wang, Sheng Yang, Gang Wang, Minghao Yu e Xinliang Feng. "Flexible in-plane micro-supercapacitors: Progresses and challenges in fabrication and applications". Elsevier, 2020. https://tud.qucosa.de/id/qucosa%3A74431.
Testo completoWu, Zhenkun. "Metal-reduced graphene oxide for supercapacitors and alternating current line-filters". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53941.
Testo completoZhang, Panpan, Feng Zhu, Faxing Wang, Jinhui Wang, Renhao Dong, Xiaodong Zhuang, Oliver G. Schmidt e Xinliang Feng. "Stimulus-Responsive Micro-Supercapacitors with Ultrahigh Energy Density and Reversible Electrochromic Window". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235489.
Testo completoLi, Hongyan, Yang Hou, Faxing Wang, Martin R. Lohe, Xiaodong Zhuang, Li Niu e Xinliang Feng. "Flexible All-Solid-State Supercapacitors with High Volumetric Capacitances Boosted by Solution Processable MXene and Electrochemically Exfoliated Graphene". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235446.
Testo completoYang, Muxuan. "Molecular Engineering of Polyaniline with Polydopamine and Graphene for All-Solid-State Flexible Micro-Supercapacitors". University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1626872581300145.
Testo completoDe, Silva Gardiyawasam L. Thushani Thilanjani. "ALL SOLID-STATE FLEXIBLE SUPERCAPACITORS WITH VERTICALLY ALIGNED MULTIWALLED CARBON NANOTUBES (MWCNT) SYNTHESIZED DIRECTLY ON METAL FOIL". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2588.
Testo completoYang, Xiangwen, Zhixing Lin, Jingxu Zheng, Yingjuan Huang, Bin Chen, Yiyong Mai e Xinliang Feng. "Facile template-free synthesis of vertically aligned polypyrrole nanosheets on nickel foams for flexible all-solid-state asymmetric supercapacitors". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224947.
Testo completoYang, Xiangwen, Zhixing Lin, Jingxu Zheng, Yingjuan Huang, Bin Chen, Yiyong Mai e Xinliang Feng. "Facile template-free synthesis of vertically aligned polypyrrole nanosheets on nickel foams for flexible all-solid-state asymmetric supercapacitors". Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30332.
Testo completoSi, Wenping [Verfasser], Oliver G. [Akademischer Betreuer] Schmidt, Oliver G. [Gutachter] Schmidt e Yongfeng [Gutachter] Mei. "Designing Electrochemical Energy Storage Microdevices: Li-Ion Batteries and Flexible Supercapacitors / Wenping Si ; Gutachter: Oliver G. Schmidt, Yongfeng Mei ; Betreuer: Oliver G. Schmidt". Chemnitz : Universitätsbibliothek Chemnitz, 2015. http://d-nb.info/1214303390/34.
Testo completoGuemiza, Hazar. "Electrodes à base d'oxyde de graphène réduit - Polymères (liquides ioniques) pour des supercondensateurs performants". Electronic Thesis or Diss., CY Cergy Paris Université, 2024. http://www.theses.fr/2024CYUN1293.
Testo completoThis thesis aims to develop flexible all-solid-state supercapacitors (SCs) for energy storage systems. For this purpose, reduced graphene oxide was selected to be used as an active material and associated with different poly(ionic liquid) (PIL) in rGO-PIL composites. The first part of this study focuses on the elaboration of rGO-PIL electrodes using conventional liquid electrolytes. Electrochemical measurements show that the presence of 10% of PIL enhances the capacitance to 80 F.g-1. The second part of this study focuses on the development of solid-state SCs. Hence PILs and a new family of polyelectrolytes obtained via the complex conservation of oppositely charged PILs called Dynamic Ion Gels was developed. Such DIGs can be a potential candidate as a safe and solid-state electrolyte as well as an ionic/polymeric intercalant agent for layered 2D materials., ensuring highly conducting continuity through the hole device. The elaboration of rGO-PIL, rGO-DIG electrodes and their association with PIL and DIGs electrolyte was elaborated. The best performances were obtained when using DIGs as electrolyte. The fabricated cell can efficiently operate at high temperatures above 80°C (28 F.g-1) with the strong enhancement of specific capacitance compared to the values at room temperature (10 F.g-1) and without any risk of liquid leakage which is not commonly obtained with conventional solvent. All these solid electrolytes can operate at an elevated potential window (2 V). Finally, the supercapacitors were made on flexible current collectors and different bending measurements were elaborated at elevated temperatures. This work demonstrated the great potential of using solid-state electrolytes which ensures safety and good performance at elevated temperatures
RAFIQUE, AMJID. "Flexible Fiber-Shaped Supercapacitor for Wearable Electronics". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2729354.
Testo completoChivers, Benjamin William. "Development of Novel PEDOT:PSS Fabrication Techniques for High Performance, Flexible RFID Antennas and Energy Storage Devices". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20155.
Testo completoCakici, Murat. "Highly flexible carbon fibre fabric based nanostructured hybrids for high performance energy storage systems". Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/18123.
Testo completoCoustan, Laura. "Matériaux pseudo-capacitifs pour supercondensateurs flexibles". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS169/document.
Testo completoSupercapacitors are attractive electrical energy storage devices for power applications. As flexible devices new integration opportunities can be consider. Nevertheless, the optimization of the energy density, weak point of these devices, proceeds through the search and the study of new electrode materials and electrolytes. In this aim, this thesis work is turned towards so called pseudo-capacitive materials, with the use of MnO2-based electrodes, and biredox Ionic Liquid electrolytes. To preserve the flexible behavior of the electrodes, the manganese dioxide was, at first, synthesized for the formulation of an ink to be sprayed on flexible substrates. The influence of dispersing agents on the electrochemical performances was evaluated. Performances of nanocomposite materials prepared with carbon nanofibers and graphene oxide sheets were also studied. Faradaic and surface contributions to the capacity developed by MnO2 electrode material were then determined by an advanced electrochemical study. Finally, the study of a new Ionic Liquid used in a symmetrical carbon/carbon supercapacitor confirmed the attractiveness of these Faradaic phenomena for the enhancement of the supercapacitor electrochemical performances
Pal, Ramendra K. "Fabrication of flexible, biofunctional architectures from silk proteins". VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4995.
Testo completoMIGLIORINI, LORENZO. "DEVELOPMENT OF FUNCTIONAL NANOCOMPOSITE MATERIALS TOWARDS BIODEGRADABLE SOFT ROBOTICS AND FLEXIBLE ELECTRONICS". Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/704286.
Testo completoBrousse, Kevin. "Intégration de micro-supercondensateurs à hautes performances sur puce de silicium et substrats flexibles". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30090/document.
Testo completoThe development of the internet of things, serving the concept of Smart Cities, demands miniaturized energy storage devices. Electrochemical double layer capacitors (or so called EDLCs) are a good candidate as they can handle fast charge and discharge over 1,000,000 cycles. This work focuses on the preparation of high performance micro- supercapacitors using non wet processing routes. Titanium carbide (TiC) thin films were first deposited on silicon wafer by non-reactive DC magnetron sputtering. The deposition parameters, such as pressure and temperature, were optimized to prepare dense and thick TiC films. Then, microporous carbide-derived carbon (CDC) films with sub-nanometer pore diameters were obtained by removing the metallic atoms of the TiC films under chlorine atmosphere. Partial chlorination led to strongly adherent TiC-CDC films which could be used as electrode in aqueous electrolyte. Capacitance values of 205 mF.cm-2 / 410 F.cm-3 were delivered in 1M H2SO4, and were stable over 10,000 cycles. In order to increase the energy density of the on-chip electrodes, the pore sizes were increased to accommodate the larger ions of organic electrolytes, by performing chlorination at higher temperatures. The 700°C chlorinated TiC-CDC electrodes delivered up to 72 mF.cm-2 within a 3 V potential window in an ionic liquid / acetonitrile mixture. Another strategy consisted in the grafting of anthraquinone (AQ) molecules, which brought additional faradic contribution to the capacitive current. Electrochemical grafting by pulsed chronoamperometry allowed to double the TiC-CDC capacitance in aqueous electrolyte (1M KOH). On-chip CDC-based micro-supercapacitors were successfully prepared via reactive ion etching/ inductive coupled plasma procedure followed by chlorination. This non-wet processing route is fully compatible with the microfabrication techniques used in the semi-conductor industry, and the as-prepared micro-devices outperforms the current state of art of on-chip micro-supercapacitors. Aside, the preparation of flexible micro-supercapacitors was achieved via direct laser-writing, which provided a facile and scalable engineering with low cost. Ruthenium oxide (RuO2)-based interdigitated electrodes were obtained from laser-writing of a commercial RuO2.xH2O / cellulose acetate mixture spin-coated onto KaptonTM. Capacitance values of ~30 mF.cm-2 were recorded in 1M H2SO4 for the flexible device. This work open the way for the design of high performance micro-devices at a large scale
HUANG, ZIH-TING, e 黃子庭. "Enhancive Performance of Flexible Composite Supercapacitors". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/n9r3re.
Testo completo國立臺灣科技大學
化學工程系
106
Composite materials were synthesized by polyaniline, polypyrrole and carbon dots on cellulose-based substrates, independently. The materials at different weights were prepared by the in-situ polymerization method. In the case of Polyaniline-series electrodes, the specific capacitance was maximum (174 F/g at a scan rate of 5mV/s) in 120μl of aniline monomer. Meanwhile, in the Polypyrrole-series film electrodes, the specific capacitance significantly decreased from 571 F/g at 5 mV/s of 240μl (pyrrole amounts) with decreasing content of pyrrole amounts. Although the specific capacitance of 180μl pyrrole amount electrode was lower than that of 240μl pyrrole amount electrode, the flexibility of 180μl pyrrole amount electrode was better than that of 240μl amount. These electrochemical results indicate that Polypyrrole-composites have better properties than PANi-series. Furthermore, the stability of polyaniline was 81% after 3000 cycles, but polypyrrole and Cdot-ppy were almost 100%. Since two polymers above indicated the inferior charge/discharge profile, carbon dots as added into in-situ polymerization with pyrrole to enhance their specific capacitance. The addition of carbon dots on composite films consisting of polypyrrole showed superior electrochemical performance in comparison with the electrode without carbon dots. Incidentally, the specific capacitance was 1073 F/g for the composite film added 100μl carbon dots. This value is 1.9 times higher than that electrode without carbon dots. Moreover, these composites film also showed better charge/discharge shape than that without carbon dots. These results indicate that this composite can produce a flexible electrode for energy storage devices with high efficiency.
Cheng, Tzu Yu, e 鄭茲瑀. "Preparation and Characterization of Graphene-based Electrodes for Flexible Supercapacitors". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/72618438426636264441.
Testo completo國立清華大學
化學工程學系
104
With the growing demand of the portable and wearable energy storage systems, the flexible supercapacitors have been received great attention. This study demonstrates that the flexible graphene nanosheets/carbon nanotube hybrid film (GS-SWCNT, GS-MWCNT) as electrode for supercapacitors and discusses the substrates (e.g. cellulose fibers and PTFE membrane) and preparation method (e.g. vacuum filtration and dip-drying) of hybrid film. The nanoarchitecture of carbon as active materials is important for energy storage. 8GS-2SWCNT exhibits much higher porosity and improves the electrical conductivities by using SWCNT as both the spacers and conductive linkers between individual graphene sheets, compared with bare graphene. Using cellulose fibers and vacuum filtration to support 8GS-2SWCNT (8GS-2SWCNT-cel(F)) which possesses 3D porous nanostructure due to the backbones of cellulose fibers and porous of carbon materials. The GS and SWCNT are strongly bound to cellulose fibers and fill the pores. This structure significantly enhances the specific surface area, improving both ionic and electronic transport kinetics. 8GS-2SWCNT-cel(F) exhibits the capacitive performance with a high specific capacitance of 127.2 F/g at 5 mV/s. Upon further decoration with MnO2 by chemical co-deposition, the MnO2/GS/SWCNT hybrid film (MnO2-8GS-2SWCNT-cel(F)) reaches a specific capacitance as high as 318.6 F/g at 5 mV/s, demonstrating the introduction of MnO2 is feasible to improve the capacitance performance. MnO2-8GS-2SWCNT-cel(F) also shows good flexibility and cycle stability (83.7 % after 5000 cycles) causes them as a promising electrode material for supercapacitor applications. The symmetric flexible supercapacitor prepared with MnO2-8GS-2SWCNT-cel(F) exhibits high energe density of 4.28 Wh/kg at a power density of 500 W/kg. Consequently, it is found that as-prepared hybrid film shows high specific capacitance, excellent rate capability, and good stability which is a promising potential application as an effective electrode material for supercapacitors.
Si, Wenping. "Designing Electrochemical Energy Storage Microdevices: Li-Ion Batteries and Flexible Supercapacitors". Doctoral thesis, 2014. https://monarch.qucosa.de/id/qucosa%3A20191.
Testo completoHuman beings are facing the grand energy challenge in the 21st century. Nowhere has this become more urgent than in the area of energy storage and conversion. Conventional energy is based on fossil fuels which are limited on the earth, and has caused extensive environmental pollutions. Additionally, the consumptions of energy are still increasing, especially with the rapid proliferation of vehicles and various consumer electronics like PCs and cell phones. We cannot rely on the earth’s limited legacy forever. Alternative energy resources should be developed before an energy crisis. The developments of renewable conversion energy from solar and wind are very important but these energies are often not even and continuous. Therefore, energy storage devices are of significant importance since they are the one stabilizing the converted energy. In addition, it is a disappointing fact that nowadays a smart phone, no matter of which brand, runs out of power in one day, and users have to carry an extra mobile power pack. Portable electronics demands urgently high-performance energy storage devices with higher energy density. The first part of this work involves lithium-ion micro-batteries utilizing single silicon rolled-up tubes as anodes, which are fabricated by the rolled-up nanotechnology approach. A lab-on-chip electrochemical device platform is presented for probing the electrochemical kinetics, electrical properties and lithium-driven structural changes of a single silicon rolled-up tube as an anode in lithium ion batteries. The second part introduces the new design and fabrication of on chip, all solid-state and flexible micro-supercapacitors based on MnOx/Au multilayers, which are compatible with current microelectronics. The micro-supercapacitor exhibits a maximum energy density of 1.75 mW h cm-3 and a maximum power density of 3.44 W cm-3. Furthermore, a flexible and weavable fiber-like supercapacitor is also demonstrated using Cu wire as substrate. This dissertation was written based on the research project supported by the International Research Training Group (IRTG) GRK 1215 "Rolled-up nanotech for on-chip energy storage" from the year 2010 to 2013 and PAKT project "Electrochemical energy storage in autonomous systems, no. 49004401" from 2013 to 2014. The aim of the projects was to design advanced energy storage materials for next-generation rechargeable batteries and flexible supercapacitors in order to address the energy issue. Here, I am deeply indebted to IRTG for giving me an opportunity to carry out the research project in Germany. September 2014, IFW Dresden, Germany Wenping Si
WEN, HE-CHUN, e 温賀淳. "Preparation and Characterization of Hydrous Ruthenium Oxide Solid State Flexible Supercapacitors". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/bqdt55.
Testo completo國立高雄科技大學
化學工程與材料工程系
107
In this study, ruthenium oxide (RuO2)-polyethylene terephthalate deposited with indium tin oxide (PET/ITO)|polyvinyl alcohol (PVA)/clay|RuO2 -(PET/ITO) flexible symmetry electrochemical supercapacitors were fabricated by using sandwich assembling technique, where RuO2-PET/ITO, cross-linked PVA/clay, and sodium sulphate acted as the electrode, the electrolyte composite membrane, and the electrolyte, respectively. RuO2-PET/ITO electrode was prepared by three-pole constant potential electrochemical deposition method, in which PET/ITO and antimony trichloride used as the substrate the plating solution. The structure of the sample was characterized by Field emission gun scanning electron microscope (FE-SEM), Thermogravimetric analysis (TGA) and Multi-function X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy. Electrochemical properties were further carried out by means of potentiostat/Galvanostat and Leak current tester. Results showed that the hydrated RuO2 is tightly bonded to the surface of PET/ITO substrate. The specific capacitance (Csp) of RuO2 electrode increased with the increasing negative electrical potential. When the potential is -0.6 V, the RuO2 electrode has the highest value of Csp (141.63 F/g), as the scanning rate is 50 mV/s, the real part of resistance is 43.5 Ω. As RuO2 electrode is annealed at 100 °C, the value of Csp (315.61 F/g) is increased due to the rearrangement of the hydrated RuO2 atom. As for electrical property analysis, RuO2|PVA/clay |RuO2 flexible supercapacitor has a specific capacitance of 24.51 F/g, the impedance is 68.44 Ω, and the energy density and power density are 17.647 Wh/Kg and 80.211 kW/Kg. After 5000 cycles test, the capacitance retention rate of RuO2|PVA/clay |RuO2 flexible supercapacitor is still 89%, the real part of impedance is 68.44 Ω. After bending 100 times at 30° bending angle, the capacitance retention rate of RuO2|PVA/clay |RuO2 flexible supercapacitor is also still 91%.
涂育誠. "The study of Bending Fatigue of the flexible Metal Additions/Graphene Supercapacitors". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/58494375244238777853.
Testo completo國立彰化師範大學
機電工程學系所
104
In this paper, several flexible metals/graphene Super-capacitors were fabricated using sol-gel methodology and their electric performance were characterized by the cyclic voltammetry measurement and the bending test. In our research, we used silver nitrate (AgNO3), nickel nitrate Ni (NO3)2, manganese nitrate and Mn (NO3)2‧6H2O as the additions. Each of them dissolved in deionized water (DI Water), and we also added some carbon blacks to enhance their conductivity. The silver additions presents the better performance than other two metals ones. We also experimented different angles by using the micro-tensile test tensile machine, discussing the performance of the electrochemistry double layer capacitance (EDLC) current-voltage relationship. Furthermore, using scanning electron microscope (SEM) we could observe the surface condition and the Specific Surface Area of our EDLC. Repeated bending test shows that the more metal additions that represent the higher electric performance to result that the resistance of bending is better. Manganese oxide is the best one to all additions. Above all, if we consider the electric performance only we could choose the silver addition, but if we consider the bending resistance only we could choose Manganese oxide to be the addition. As the results be they could be the guideline of selecting the better materials to fabricate the Super-capacitors.
Tsai, Kun-Ju, e 蔡昆儒. "SWCNT/Ni-Co-Mn hydroxide nanohybrid materials as electrodes for flexible supercapacitors". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8z5daq.
Testo completoTsai, Sung-Ying, e 蔡松穎. "Preparation of the Porous Array Electrodes and Their Applications on Flexible Supercapacitors". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/r8tx53.
Testo completo國立虎尾科技大學
光電工程系光電與材料科技碩士班
104
The soft electronic era did come. Many lightweight flexible electronic devices such as the flexible panel display, flexible solar cell and the wearable electronics have been extensively studied. Thus, a highly efficient energy storage device was required for all of soft electronic devices. Supercapacitors are also known as electrical double-layer capacitors or ultracapacitors. The function of the supercapacitors is between the traditional capacitors and electrochemical cell, which also can be regarded as an ideal energy storage element. The advantages of supercapacitors including faster charge/discharge rate, high energy density, long lifetime, and low maintenance cost were the major advantages of supercapacitors which make them ideal candidates for energy storage. However, the energy storage performance of the supercapacitors is mainly affected by the electrode surface characteristics and the contact area between electrodes and electrolyte. Therefore, preparing of porous electrodes is reasonable to increase the storage effect of the supercapacitor. In this study, polystyrene (PS) microspheres were synthesized by dispersion polymerization technique first. Then, porous Polydimethylsiloxane (PDMS) array structure was fabricated by soft-lithography method. Later, a conducting layer was coated on the surface of porous array after the multi-walled carbon nanotube (MWCNT) and Graphene (G) mixture suspension pouring into the porous array. A H3PO4/PVA gel electrolyte was filled between two porous electrodes; a porous PDMS-based supercapacitor was assembled in a sandwich structure after a separator inserting. The specific capacitances, electrochemical analysis, cycle stability of the porous electrode supercapacitors were explored. This porous electrode-based supercapacitor exhibits a high specific capacitance and good cycle stability, which has enormous potential applied in wearable and portable electronic products in the future.
Chen, You-Feng, e 陳有豐. "Flexible solid-state oxide supercapacitors and their capacitive performances: fabrication of manganese oxides with porous framework on flexible textiles". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/87171432857161768606.
Testo completo國立中興大學
化學系所
103
In this study, three dimensional (3D) porous MnO2 networks assembled from interconnected MnO2 nanosheets onto carbon nanotube flexible textile substrates have been prepared by a simple and fast electrodeposition method. With such unique 3D networks, enhance electrolyte-accessible surface areas and facilitate easy access of electrolyte ions into the interior of the electrodes can be achieved, which can result in good electrochemical capacitive properties. We use the 3D porous MnO2 networks materials as the electrode and the poly(vinyl alcohol) as the electrolyte to fabricate flexible solid-state supercapacitors, which exhibits a high specific capacitance of 342.1 F/g at 0.5 A/g, comparable energy density and power density, good cycling stability of ~75 % capacity retention and 90 % Coulombic efficiency after 5000 cycles, and good mechanical flexibility. These results indicate that our device can be expected to be promising for the application in flexible energy storage systems.
Chiu, Hsin-Ya, e 邱欣雅. "Application of Mixed-Phase MnO2/N-Containing Graphene Composites to Flexible Asymmetric Solid-State Supercapacitors". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7vz3t7.
Testo completo國立暨南國際大學
應用材料及光電工程學系
107
In this study, the electrode active materials of supercapacitors were prepared by a low-cost facile hydrothermal approach. The N-containing graphene/MnO2 composites (x-NGM) were obtained by growing α- and γ-phase MnO2 nanostructures on the surface of N-containing graphene. A PVA/LiCl electrolyte gel membrane was employed as the separator between two electrodes for supercapacitors. By changing the content of Mn and adjusting the mass loading of active materials, the capacitance characteristics of various electrodes and devices were investigated. Excessive Mn contents were proven to be detrimental to ion transport and faradaic charge transfer, and inferior capacitance characteristics were thereby resulted. Too much mass loading was also demonstrated to decrease conductivity, leading to worse capacitor performance. After calculation by CV results, the 3-NGM1//G1 device exhibited the highest specific capacitance of 579 F·g-1. The corresponding energy and power densities were 73.6 Wh·kg-1 and 4400.0 W·kg-1, respectively, implying its rapid charge/discharge capacity. After 2000 bending cycles under the current density of 1 A·g-1 by GCD method, the retention rate of specific capacitance was found to be around 86.71 %. The high flexibility, cycling stability, and good capacitance properties could be attributed to the synergistic effect of mixed-phase MnO2 and N-containing graphene. By combining the electric double-layer material with pseudo-capacitance materials, the two charge storage mechanisms were joint to improve charge transfer, conductivity, and thus capacitor performance.
Wang, Jeng-An, e 王政安. "Preparation and Characterization of Novel Bifunctional Waterborne Polyurethane-Potassium Poly(acrylate) Polymer for Flexible Supercapacitors". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5nqd84.
Testo completo國立清華大學
化學工程學系
107
This study focuses on the preparation and the performance of the supercapacitor for energy storage devices. The research topics of this dissertation are related to the preparation and properties of novel absorbent polymer, polyurethane - potassium poly(acrylate) (WPU-PAAK), which not only forms the gel polymer electrolyte but also substitutes the commercial binder between electrode materials. There are three parts in this study: (1) Synthesis and characterization of the novel polymer for the electrolyte and adhesive in flexible all-solid-state electrical double-layer capacitors. (2) Mechanism of bi-functional WPU-PAAK polymer in both electrodes and electrolyte. (3) High performance asymmetric supercapacitor NaxMnO2@CNT /WPU-PAAK/AC-CNT The objective of the first part (chapter 3) of this dissertation is to develop a sticky network copolymer, WPU-PAAK. The cross-linked structure is believed to not only enhance the water retention but also provide the mechanical strength in gel polymer electrolyte (GPE). This interesting polymer can avoid the swelling or drying of GPE due to its naturally adsorption/desorption of moisture from the ambient environment. This polymer neutralized with 1 M KOH and soaked with various alkaline solutions (denoted as WPU-PAAK-M, M: Li, Na, K) which can act not only as an electrolyte but also as an adhesive for both positive and negative electrodes for flexible quasi solid-state electrical double-layer capacitors (EDLCs). The PAA backbone chains in the copolymer increase the amount of carboxyl groups and promote the segmental motion. The carboxyl groups enhance the water-uptake capacity which facilitates the ion transport and therefore improves the ionic conductivity. The cross-linked agent, WPU chains, effectively keeps the water content and provides the unique stickiness to serve as a binder for electrodes. The WPU-PAAK soaked with alkaline solutions exhibits an ionic conductivity which is greater than 10-2 S cm-1. A commercial available carbon paper treated with acidic solutions (denoted as ACP) demonstrates excellent capacitive behavior using the WPU-PAAK-K polymer electrolyte. From the cyclic voltammetric test, this ACP shows a high area capacitance of 211.6 mF cm-2 at 10 mV s-1. In the electrochemical impedance spectroscopic analysis, a full cell of ACP/WPU-PAAK-K/ACP displays a low equivalent series resistance of 0.44 Ω in comparison with the other cells using commercial available polymer electrolytes. A quasi solid-state ACP/WPU-PAAK-K/ACP EDLC provides an excellent specific capacitance of 35.5 mF cm-2 at 0.5 mA cm-2. This device with over 90 % capacitance retention under 180o bending angle shows an outstanding flexibility. The objective of the second part (chapter 4) is to develop a high performance supercapacitor by generating the ionic tunnel in the electrode material. To further enhance the performance of flexible supercapacitor, a high surface area (~2500 m2/g) activated carbon, namely ACS 25, was used as electrode material in this study. And the commercial binder of poly(vinylidene fluoride) (PVDF) was substituted by WPU-PAAK in electrode materials. This hydrogel of WPU-PAAK not only acted as the adhesive between each particle of electrode active materials, but also formed the ionic tunnel in the electrode materials, which can more deeply bring the electrolyte ions into the inner site of active materials to enhance the effective area in the interface of electrode and electrolyte. The results show that WPU-PAAK binder in substitution for PVDF binder can enhance the specific capacitance of active electrode about 64 % in current density of 1 A/g. In the high current density of 10 A/g, it can even enhance over 100 % in specific capacitance. Furthermore, the areal specific capacitance of active electrode, which used the WPU-PAAK binder, was increased with the increasing of mass loading in the same ratio. The quasi solid-state device of the sandwich type demonstrates a potential window of 1.4 V and a high device-areal specific capacitance of 122.43 mF cm-2 at 1 mA cm-2. This highly flexible electrical double-layer capacitor (over 95.6 % areal specific capacitance retention at a bending angle of 180o) also delivers an energy density of 33.33 Wh cm-2 at a power density of 0.7 mW cm-2 with an excellent cycle life of 87.5% retention in the 10,000-cycle test. The objective of the third part (chapter 5) is to develop a high performance supercapacitor by enhancing the specific capacitance and potential window. Therefore, this study tries to use the pre-intercalation of Na+ in MnO2 to improve the pseudocapacitance, and also building NaxMnO2@CNT/AC-CNT asymmetrical assembly to enlarge the potential window. According to our previous research, the pre-intercalution of Na+ can optimize the redox reaction in MnO2 to increase the specific capacitance. In addition, the use of CNTs could be beneficial to optimize the electronic conductivity in MnO2. Therefore, this study will explore the performance optimization in the ratio of CNT and NaxMnO2. From the results, NaxMnO2@CNT21 shows the best electrochemical performance. Which exhibits the highest specific capancitance of 150 and 130 F/g at current density of 1 and 20 A/g in 1 M Na2SO4 electrolyte. Furthermore, the specific capacitance of NaxMnO2@CNT21 can be further increased to 330.2 and 140.4 F/g at different current densities in WPU-PAAK-1M Na2SO4 gel polymer electrolyte. This quasi solid-state asymmetrical device, NaxMnO2@CNT21/WPU-PAAK-1M Na2SO4/AC-CNT, shows a potential window of 1.53 V and a high device-areal specific capacitance, specific energy density and specific power density of 301.9 mF cm-2, 130.51 uWh cm-2 and 1.03 mW cm-2 at 1 mA cm-2, respetively. This highly flexible asymmetrical supercapacitor (over 92.4 % areal specific capacitance retention at a bending angle of 180o) also exhibits an excellent cycle life of 90 % and 72.2 % retention in the 5,000-cycle and 10,000-cycle test.
Lee, Ka Yeung Terence. "Study of Flexible Multi-wall Carbon Nano-tubes / Conductivepolymer Composites for Supercapacitor Applications". Thesis, 2014. http://hdl.handle.net/1807/65575.
Testo completoTo-WenTsao e 曹多雯. "Fabrication of CsxWO3/reduced graphene oxide/PEDOT:PSS nano-hybrids for flexible all-solid-state transparent supercapacitors". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/97djq2.
Testo completoQui, Le Van, e 黎文規. "van der Waals Heteroepitaxial AZO/NiO on Muscovite for Transparent Flexible Electronic Devices as Memristors and Supercapacitors". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8x5vks.
Testo completo國立交通大學
材料科學與工程學系所
107
Multifunctional electronics featuring optical transparency, portability, mechanical flexibility, light-weight and environment-friendly are of great demands for next-generation smart electronics. Memristor and supercapacitor represents the important chains in next-generation devices as the information and/or energy storage components, respectively. In this thesis, nickel oxide (NiO) and aluminum doped zinc oxide (AZO) are fabricated on muscovite via pulsed laser deposition and sputtering method. By changing the morphology of heterostructure are suitable to develop some advantage applications: We design the transparent flexible structure based on van der Waals heteroepitaxial AZO/NiO/AZO/muscovite (ANA/muscovite) for a memristor application. The ANA/muscovite memristor satisfies all the hardest requirements of a transparent soft device such as optical transparency over 80 % in visible light and high performance with an ON/OFF resistance ratio >105, stable endurance to 103 cycles and long retention time of 105 s. In addition, the ANA/muscovite memristor can work at various bending radii down to 5 mm, a mechanical bending after 1000 cycles at a curvature with a radius of 6.5 mm and a high temperature up to 185 oC. On the other hand, AZO nanorod (NRs) and NiO coated AZO NRs on muscovite mica are fabricated via radio frequency magnetron sputtering deposition method. AZO NRs and AZO/NiO NRs exhibit excellent properties as potential electrodes for next-generation applications as good conductivity, high transparency, stable sheet resistance under compressive and tensile strain down to 5 mm bending radius or mechanical strain after 1000 bending cycles. The obtained symmetric solid-state supercapacitor based on these electrodes display good performance with a large areal specific capacitance of 3.4 mF/cm2, long cycle life 1000 times, robust mechanical properties and high chemical stability. These results deliver a concept to open up new opportunities for future applications in transparent flexible information and energy storage.
Jun-YiWu e 吳俊逸. "Fabrication of nano-carbon/PEDOT:PSS hybrid thin films for flexible transparent conductive electrodes and all-solid-state supercapacitors". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/36eb6g.
Testo completo國立成功大學
化學工程學系
104
This thesis concerns the developments of flexible transparent conductive electrodes and supercapacitors using carbon nanotube (CNT), reduced graphene oxide, and their hybrids with conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). At first, the CNT and rGO-based thin films were fabricated as flexible transparent conductive electrodes by the blade-coating of CNT or graphene oxide (GO) dispersion on polyethylene terephthalate (PET) and the followed GO reduction with hydroiodic acid for the case of GO. The decreases of transmittance and sheet resistance with the increase of layer numbers have been described. Secondly, CNT or GO (0~0.1wt%) was added to the equal volume mixture of PEDOT:PSS and dimethyl sulfoxide (DMSO) to yield homogeneous dispersions. For the case of GO, the dispersion was further microwave-treated to obtain the rGO dispersion. Then, the CNT or rGO dispersion was blade-coated on PET to form the CNT/PEDOT:PSS or rGO/PEDOT:PSS hybrid thin films as flexible transparent conductive electrodes. It was found that the appropriate addition of CNT or rGO indeed could effectively enhance the conductivity via the formation of conductive network. The lowest sheet resistance around 1000 Ω with a transmittance above 80% was obtained for both the hybrid thin films. Finally, it was demonstrated that both the CNT/PEDOT:PSS and rGO/PEDOT:PSS hybrid thin films also could be used as the electrodes for supercapacitors. The capacitance could be raised by appropriately increasing the thickness of hybrid thin films. Furthermore, the flexible transparent all-solid-state supercapacitors were fabricated with polyvinyl alcohol/sulfuric acid (PVA/H2SO4) gel electrolyte between two CNT/PEDOT:PSS or rGO/PEDOT:PSS hybrid thin film-based electrodes. It was found that both the resulting supercapacitors had transmittances above 56% and could be quickly charged and discharged. Also, their electrochemical performance could be retained while bending. All the results revealed that both the CNT/PEDOT:PSS and rGO/PEDOT:PSS hybrid thin films could be developed as good electrode materials for flexible transparent supercapacitors.
Liao, Chen-Yu, e 廖振宇. "Flexible polyaniline/graphene nanocomposite supercapacitor". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6zfjdz.
Testo completo國立臺灣大學
應用力學研究所
105
We investigate polyaniline (PANI)/reduced graphene oxide (rGO) composite supercapacitor post-annealed at various temperatures. Pastes containing PANI and rGO are first screen-printed onto carbon cloth. Following which the sample was annealed at 100, 200, and 300 °C for 10 min. Thermogravimetric analysis indicates the decomposition of PANI as the annealing temperature increased to 200 and 300 °C, the pseudocapacitance contributed by PANI decreases, and the capacitance values therefore decreased. 100 °C×10 min annealing can increase the areal capacitance from 88.55 mF/cm2 to 102.73 mF/cm2. Under bending with a bending radius of 0.55 cm, the capacitance retention rate is 90.7 %. After 1000 cycle CV stability test, the capacitance retention rate is 88.25 %.
Chen, Zhi-Hong, e 陳志宏. "Nickel-based thin film supercapacitior electrodes on flexible substrates". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8e9g7h.
Testo completo義守大學
材料科學與工程學系
103
In this study, electroless Nickel and Nickel – Cobalt coatings were deposited on three kinds of flexible substrates (graphite paper, titanium foil, carbon fiber paper), and these coatings further etched in a 5M HNO3 solution to improve the electrochemical characteristics. Using a three-pole electrode system, cyclic voltammetry and charge-discharge curve were measured to calculate the specific capacitance, and electrochemical impedance spectroscopy (EIS) was used to analyze the electrochemical reaction mechanisms. In addition, the effects of Ni/Co ratios of Ni-Co-P system and etching time on the microstructure and the specific capacitance were explored in details. The results showed that nickel-phosphorus coating on the graphite paper substrate exhibited the highest specific capacitance (71 F/g) than the others (Titanium foil: 30 F/g; carbon fiber paper: 52 F/g) under the same plating conditions. After etching in HNO3 solution for 10s, the specific capacitance of Ni-P coating on graphite paper increased up to 335 F/g, in which the specific capacitance of Ni-P coating increase to 4.7 times as compared with the unetched one. Once the etching time was further increased, it did not significantly increase the specific capacitance. Microstructures analysis revealed that an appropriate etching time can effectively increase the surface area of Ni-P coatings and the prolonged etching time damaged the Ni-P coatings and finally the etched coatings peeled off. To deposit Ni-Co-P coatings on graphite paper, the pH value of electroless bath should be changed into 9. The specific capacitance value is not significantly improved by the addition of Co, but the corrosion resistance of the coating is improved. After etching in 5M nitric acid solution, it also significantly raised specific capacitance, for Ni/Co=70/30 system, at a scan rate of 10mV/s, from 51 F/g to 237 F/g. Based on the above the results, the acid-etching treatment effectively increased the specific capacitance of the Ni-P and Ni-Co-P system, it is expected that such method be applied to other material systems.
Chang, Cheng-Ming, e 張正明. "Biotemplate Hierarchical Polyaniline Composite Films for High Performance Flexible Supercapacitor Devices". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/13773405163797263332.
Testo completo中原大學
化學研究所
104
Highly flexible and foldable supercapacitor devices assembled using biotemplated polyaniline composite electrodes are described for the first time in this paper. This electrode architecture provides a facile fabrication route for creating abundant multiscale structures by using a plant species design based on nature resources and facilitates designing a hierarchical ordering morphology that improves the redox exchange and ionic diffusion resistance between the electrodes and electrolyte. The polyaniline composite was prepared using a replica technique and synthetized through in-situ oxidative polymerization by using aniline with conductive carbon materials. The biotemplated electrodes show a high electrochemical specific capacitance of 626 F g−1 in a three-electrode system, an excellent mechanical strength for enduring Z-type folding, and high cycling stability with capacity retention of 87% (545 F g−1). Furthermore, in cyclic voltammetry analysis, the prototype devices exhibit extraordinary elasticity without side reactions in various bending angles. Regarding electrochemical performance, the device responds with a high energy density of 5.06 Wh kg−1 and a high power density of 1685 W kg−1 when based on composite thin film electrodes and maintains 85% cycling retention as well as electrode performance after 1000 cycles. This study clearly reveals that fabricating hierarchical polyaniline composite electrodes through biotemplating yields high electrochemical performance and flexibility, making the electrodes useful for application in energy storage devices for portable electronic products.
Kang, Yu-Yao, e 康宇堯. "Fabrication of integrated device with flexible dye-sensitized solar cell and graphene supercapacitor". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/kk9776.
Testo completo國立虎尾科技大學
電子工程系碩士班
107
Currently, flexible surfaces are becoming more common in electronic devices. Electronic devices fabricated on flexible substrates are considered to have potential. Flexible supercapacitors with long cycle life, high power density, stability and flexibility.In this study, a flexible supercapacitor was prepared activated carbon-doped graphene, and integrated a flexible dye-sensitized solar cell, completed energy conversion/storage components.Baking method for making activated carbon doped graphene carbon powder, carbon-doped graphene paste is used supercapacitor electrode by spin coating. Using a press machine to transfer, TiO2 film on the quartz substrate can transfer the TiO2 film on the ITO/PEN plastic substrate after high temperature sintering, Complete flexible dye-sensitized solar cell. The sample doped 0.05wt% graphene had the best capacitance value. The capacitance value of 218F/g,the charge and 85% of charge/discharge efficiency. The flexible supercapacitor maintained its supercapacitor performance well, even under twisted, bent, or rolled conditions. The flexible dye Sensitized solar cell photoelectric conversion efficiency of 2.5%, integrated components for serial and parallel connection to successfully illuminate the LED.
Chen, Yu-Liang, e 陳昱良. "Au Nanostructures on Flexible Substrate: Fabrication and Applications in Biosensor and Supercapacito". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/99674687789499474579.
Testo completo國立交通大學
應用化學系碩博士班
102
In this thesis, we studied fabrication of Au nanostructures on flexible substrate and its applications in biosensor and supercapacitor. A facile fabrication of high density Au nanostructures including nanothorns (NTs), nanocorals (NCs), nanoslices (NSs), and nanowires (NWs) which were electrochemically grown on flexible plastic substrates of polyethylene terephthalate (PET). By adjusting the electroplating conditions, we proposed a growth mechanism of Au nanostructures. Among them, the specific real surface area (RSA) of the Au NWs is the highest one (26100 cm2/g). This is due to the high aspect ratio of the one-dimensional NW structure. Further, as-fabricated Au nanostructures on flexible substrate were employed and used as electrode in biosensor and supercapacitor applications. For biosensor application, a thrombin-binding aptamer was immobilized on the surfaces of the Au nanostructures to form highly sensitive electrochemical impedance spectroscopic (EIS) as biosensors for thrombin recognition. The binding of thrombin to the aptamer was monitored by EIS in the presence of [Fe(CN)6]3-/4-(aq). The protein (1 – 50 pM) was detected linearly by the Au nanostructures. Among them, the Au NWs exhibited excellent thrombin detection performances (1130 pM-1 cm-2). The biosensor provided high sensitivity, selectivity, and stability due to its high surface area. For supercapacitor application, electrodes composed of ultrathin MnO2 (thickness 5 - 80 nm) spines on Au NW stems (length 10 - 20 μm, diameter 20 - 100 nm) were electrochemically grown on flexible PET substrates. The electrodes demonstrated high specific capacitance, high specific energy value, high specific power value, and long-term stability. In Na2SO4(aq) (1 M), the maximum specific capacitance was determined to be 1130 F/g by cyclic voltammetry (CV, scan rate 2 mV/s) using a three-electrode system. From a galvanostatic (GV) charge/discharge test using a two-electrode system, a maximum capacitance 225 F/g (current density 1 A/g) was measured. Even at a high charge/discharge rate 50 A/g, the specific capacitance remained at an extremely high value 165 F/g. The flexible electrodes also exhibited a maximum specific energy 15 Wh/kg and a specific power 20 kW/kg at 50 A/g. After five thousand cycles at 10 A/g, 90% of the original capacitance was retained. A highly flexible solid-state device was also fabricated to reveal its supercapacitance performance.
Sari, Nurlia Pramita, e 薩敏娜. "Three-Dimensional Electrode Self-Assembly of Electrochemical Exfoliated Graphene for High-Performance Flexible Supercapacitor". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/99119505804009136969.
Testo completo國立中央大學
機械工程學系
104
In this study, we report a flexible supercapacitor including a unique macroporosity self-assembly of graphene as electrode. The graphene supercapacitor made by three-dimensional graphene electrodes were prepared by electrochemical exfoliated graphene (EC-graphene) follow by freeze-dried and annealed process. Here we study the effects of macroporous structured electrodes on capacitor performance by altering the graphene concentration. Moreover, flexible supercapacitor devices made by such unique electrodes were demonstrated by using gel electrolyte (1M H2SO4 /PVA). We found out the pore size of 3D graphene electrodes correlated to the solution concentration of initial graphene suspension, where the pore size were 4.88μm, 1.19μm, 1.02μm, 0.39μm corresponding to 10 mg/mL, 15 mg/mL, 20 mg/mL, and 25 mg/mL, respectively. The result shows that graphene electrode exhibit superior high specific capacitance of 45.40 F/g in liquid electrolyte (6M KOH) and 23.89 F/g in gel electrolyte (1M H2SO4/PVA) at low concentration of graphene (10mg/mL), which was higher than that (31.85 F/g in liquid electrolyte and 10.43 F/g in gel electrolyte) of samples prepared at high concentration (25 mg/mL). The device shows excellent rate performance and cycling stability. It was clearly seen the larger pore sized electrodes, result in higher capacitance which was due to few-layered stacked graphene creating more accessible surface area and better kinetic process of ion diffusion. In addition, it can be seen that the dipping method can be used to gain higher performance of flexible supercapacitor. The specific capacitance of EC-graphene without dip is 17.23 F/g (27.91% lower than dipping method). This can be caused by higher efficient ion diffusion in sample dips into dilute PVA-H2SO4 electrolyte due to more time electrolyte immersed into electrode. Moreover, it was found out that EC-graphene shows higher performance than conventional used reduced graphene oxide(rGO) (43.45 F/g in 6M KOH electrolyte), which was attributed to its poor electrical conductivity (sheet resistance of rGO 7.07x10-3 Ω/sq while EC-Graphene 6.60 x10-3 Ω/sq) and lower oxygen functional groups. The flexible supercapacitor, exhibit superior working stability during the bending testing, where 94% of capacitance was preserved for bending angle up to 180o and 90% after 50 times bending cycles. This work introduces a new concept of flexible, environment friendly, large scale production, and high performance graphene-based supercapacitors that could have a way for practical applications in energy devices.
Lien, Chieh, e 連婕. "The Study and Application of Nickel-based GNS/Plant Fiber in Flexible Asymmetric Supercapacitor". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/34454105435082920334.
Testo completo國立中興大學
化學工程學系所
102
As the supercapacitors can provide a higher power density than conventional batteries, it has become a potential application in the energy storage device. Asymmetric supercapacitor is assembled by two slightly different electrode''s materials, and the operating voltage can be enhanced and the capacities and energy densities also be dramatically improved. In this study, we have combined the excellent electric properties of graphene with the flexibility of the plant fibers into a flexible composite electrode, and finally assembled into symmetric and asymmetric supercapacitor. Graphene are uniformly mixed with plant fibers and dried to form a graphene composite electrode.Using electroless plating method to plate nickel on the surface of graphene sheets composites. By controlling the plating time, we can obtain different ratios of Ni/Graphene. Nickel was partially oxidized to nickel oxide because of high-temperature calcinations. The different ratios of Ni/NiO/Graphene composites then formed as a positive electrode of asymmetric supercapacitor. These composite materials will be tested with TGA, XRD andSEM equipments. With KOH and polymer gel as the electrolyte, we assembled the positive and negative electrodes into asymmetric supercapacitors. By the electrochemical test, the electrochemical properties could be obtained to identify optimal conditions for the preparation of flexible asymmetric supercapacitor. By using KOH as electrolyte, the asymmetric supercapacitor has a capacitance value 77.5 F g-1 at a current density of 0.5A g-1. On the other hand, the flexible asymmetric supercapacitor still maintain its own characteristic during bending, showing good flexibility. It has a capacitance value 34.61 F g-1 at a current density of 0.2A g-1. The supercapacitor exhibits excellent stability with nearly no decrease after 500 cycles.
Cheong, Sh-Shen, e 鍾思森. "Fabrication and application of metal oxide/carbon-based material/polyaniline nanocomposites for high-performance flexible supercapacitor". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/j274n4.
Testo completo國立臺灣大學
材料科學與工程學研究所
106
Flexible electronic devices have great potential as a new generation, light weight, flexible wearable applications for healthcare, communication and sportswear. The flexible supercapacitors are one of the most promising candidates due to their long cycle stability, high power density and safety. In this thesis a binary composites of oxidized carbon nanotube or graphene/PANI, ternary composites of oxidized carbon nanotube/graphene/PANI and quaternary composites of metal oxides/oxidized carbon nanotube/graphene/PANI were prepared by electro-polymerization deposition on carbon fiber and carbon cloth respectively. Their surface morphology and compositions were investigated by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDX) and Fourier transform infrared spectroscopy (FTIR). The results conform the formation of composite material. The particle size and size distribution of the metal oxides were measured by transmission electron microscopy (TEM), X-ray diffraction (XRD) and dynamic light scattering (DLS). Electrochemical measurements including galvanostatic charge discharge, cyclic voltammetry and electrochemical impedance were employed to evaluate their specific capacitance. The highest specific capacitances reach to 1084F/g, 888F/g, and 804F/g at 1A/g and 803F/g, 563F/g, and 371F/g at 20A/g for oxidized carbon nanotube/graphene/PANI composites incorporating with 1wt%RuO2, 2wt%MnO2 and 1wt%NiO respectively. Flexible Symmetrical Supercapacitor (FSSC) were also fabricated by using GO/EMITFSI ionic liquid composite as gel type electrolyte. The FSSC shows a remarkable performance including good capacitance (513 F/g, 478 F/g, 441 F/g, 431 F/g, 394 F/g at 1A/g for 1wt%RuO2/oxidized carbon nanotube/graphene/PANI, 2wt% MnO2 oxidized carbon nanotube/graphene/PANI, 1wt%NiO/ oxidized carbon nanotube/graphene/PANI respectively), great capability retention at 20A/g and excellent cycle life. 1wt%RuO2/oxidized carbon nanotube/graphene/PANI shows the maximum energy density of 37Wh/kg and the highest power density of 13kW/kg. We also demonstrate actual performance of FSSC by lighting up a red LED. Therefore, our study for flexible supercapacitor holds great potential for next generation lightweight and flexible electronics.
Huang, Tse-Yu, e 黃則毓. "Fabrication and applications of metal oxide/nano-carbon material/polypyrrole nanocomposite electrodes for high-performance flexible supercapacitor". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/y22j56.
Testo completo國立臺灣大學
材料科學與工程學研究所
106
Supercapacitors can be applied to communication and healthcare industries due to their high power density, long cycle life and friendly to environment. Because flexible supercapacitors have convenience to personal life, they have great potential to develop as a next-generation and wearable electronic gadget. Our purpose of research is to fabricate a supercapacitor device with high specific capacitance, high energy density, high power density and long cycle life. In our research, electrode of polypyrrole(PPy), binary system electrode of graphene/PPy and oxidized carbon nanotube/PPy, ternary system electrode of graphene/oxidized carbon nanotube/PPy and quaternary system electrode of metal oxide(RuO2, MnO2 or NiO)/graphene/oxidized carbon nanotube/PPy were individualy prepared by electrochemical polymerization deposition on carbon fiber and carbon cloth respectively, and we adjusted parameters of different compositions of materials and polymerization time in this experiment. We also used Fourier transform infrared spectroscopy(FTIR) to investigate the interaction between materials, scanning electron microscopy(SEM) to investigate the surface morphology and energy dispersive X-ray microanalysis(EDX) to analyze the compositions of quaternary electrode. We used galvanic charge-discharge method and cyclic voltammetry to analyze the electrochemical properties of electrodes. For the system of carbon cloth substrate, the quaternary electrode of RuO2/graphene/oxidized carbon nanotube/PPy with polymerization time of 300s has the best specific capacitance of 1017.1F/g at current density 1A/g measured by galvanic charge-discharge method and has specific capacitance retention of 70.8% at 20A/g. It also has the best specific capacitance of 1034.1F/g at scan rate 5mV/s measured by cyclic voltammetry, and has specific capacitance retention of 70.1% at 100mV/s. We further fabricated the flexible symmetric supercapacitor device(SSC) with above mentioned electrodes by using GO/EMITFSI as gel electrolyte and used galvanic charge-discharge, cyclic voltammetry and electrochemical impedance to analyze the electrochemical properties of devices. SSCs with symmetric electrodes of RuO2/graphene/oxidized carbon nanotube/PPy, MnO2/graphene/oxidized carbon nanotube/PPy, NiO2/graphene/oxidized carbon nanotube/PPy, graphene/oxidized carbon nanotube/PPy and PPy have the highest specific capacitance of 561.6F/g, 517.1F/g, 475.9F/g, 370F/g and 322.9F/g at current density 1A/g and have specific capacitance retention of 44.3%, 43.5%, 44.5%, 56% and 41% at 20A/g respectively. Their specific capacitances at scan rate of 5mV/s were 589.5F/g, 535F/g, 489.8F/g, 384.2F/g and 335F/g at scan rate 5mV/s with the specific capacitance retention of 44.1%, 44.2%, 44.1%, 54.3% and 44.2% at 100mV/s respectively. We found the device of RuO2/graphene/oxidized carbon nanotube/PPy has the best specific capacitance and energy density of 38.11Wh/kg and has specific capacitance retention of 89.5% after 1000 charge-discharge cycle. Finally, we use four devices of RuO2/graphene/oxidized carbon nanotube/PPy in series to light up a red LED to demonstrate our SSCs having great potential for next generation electronic gadgets.
Su, Dung-Yue, e 蘇東裕. "Silver nanowires and graphene sheets apply on applications of flexible electrode, supercapacitor and stretchable gas-permeation barrier". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/64n2p7.
Testo completo國立臺灣大學
材料科學與工程學研究所
107
The dissertation focus on development of flexible electrode and stretchable gas barrier. For the field of flexible electrodes, synthesis of silver nanowires (AgNWs) and integration of AgNWs with atomic layer deposition (ALD) in flexible electrodes and supercapacitors were studied to address the key issues of flexible electronics: (i) nature brittle and insufficient performance of indium tin oxide (ITO), which is current dominant material of transparent conductive electrode, and (ii) major goal of energy storage: high capacitance and cost-effective fabrication. In the part of synthesis of silver nanowires, we developed a solution processed route to synthesize silver nanowires with high aspect ratio in ambient condition through optimizing copper bromide concentration and injection of ultrasonic atomization of silver precursor. In the part of transparent conductive gas barrier, we utilized a novel ALD hafnium-doped zinc oxide (HZO) process, a good transparent conductive gas barrier process developed in our laboratory. To deposited thin HZO layer with plastic-compatible temperature, excellent gas barrier performance and flexibility, integrating with silver nanowires film and H2O2 treatment of AgNWs interfaces, we successfully developed a HZO/AgNW hybrid transparent conductive gas barrier with performance superior to ITO/PET. In addition, we also demonstrated the feasibility of the HZO/AgNW hybrid film for perovskite solar cells, which can simultaneously as transparent electrode and electron collection layer, and the cells using hybrid films displayed slightly better photovoltaic performance than the devices using commercial ITO as electrode. In the part of supercapacitor, we utilized high surface-area silver nanowires network, which could be fabricated by spray coating of silver nanowires, and integrating with ALD dielectric and conductive layer to fabricate supercapacitor with high volumetric capacitance (193.5 mF/cm3). In the part of stretchable gas barrier, we utilized solvent exchange method, which could significantly improve graphene dispersibility in polyurethane. Therefore, tortuous path of gas in polyurethane was prolonged, and resulting in respectable WVTR reduction, and its comprehensive properties were improved.
Chen, Po-Hsiang, e 陳柏翔. "The Fabrication of Modified Graphene sheet and Electrospun Polyamide 6,6 Fiber Nanocomposite and its Application in Flexible Electrode for Supercapacitor". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/07184258444513484567.
Testo completoTAI, WEI-CHING, e 戴瑋慶. "Electrochemical deposition and characterization of MnO2/rGO on porous nickel of inverse opal structures on a flexible substrate for supercapacitor applications". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/fm22kz.
Testo completo逢甲大學
材料科學與工程學系
107
This work is consisted of five experimental procedures including (i) formation of graphene oxide (GO) via Hummers' method, (ii) production of photonic crystals (PhCs) of PS microspheres on the ITO glass substrates via electrophoretic self-assembly (EPSA) route, (iii) development of template-mediated technique to create a nickel inverse opal structure (IOS) via electrochemical deposition (ECD), (iv) MnO2/Ni foam, MnO2/rGO/Ni foam and MnO2/rGO/Ni-IOS samples were prepared by ECD, and (v) sample property analysis of their microstructure structures and electrochemical characteristics. We successfully fabricated the 3-D PhCs of PS microspheres, which were of various size-distributed and well-dispersed features via emulsifier-free polymerization. Tuning electrochemical deposition time is able to control the thickness of the structure of nickel metal PhCs with invers opal structure. Electrochemical deposition of rGO/Ni-IOS through deposition voltage and deposition time led to the optimal electrochemical characteristics, and then the MnO2/rGO/Ni-IOS structure electrode of supercapacitor sample made by ECD route with constant voltage of 0.4 V and deposition time of 3 min had a rather outstanding specific capacitance of 2,060 F/g under a charging-discharging (CD) test at current density of 2 A/g. The specific capacitance of such a sample can still maintain at 91% level of the original specific capacitance after 2,000 cycles. In this study, we successfully demonstrated that the fabrication of a unique composite of nickel sulfide active media and a highly porous nickel metal media in an inverse opal structure prepared by EPSA and ECD can provide a great contribution for designing novel supercapacitor devices.
Bandari, Vineeth. "Towards Smart Motile Autonomous Robotic Tubular Systems (S.M.A.R.T.S)". 2021. https://monarch.qucosa.de/id/qucosa%3A75964.
Testo completo