Dissertations / Theses on the topic 'Potassium batterie'

Thanks to their superior energy and power density, lithium-ion batteries (LIBs) currently dominate the market of power sources for portable devices. The economy of scale and engineering optimizations have driven the cost of LIBs below the 200 $/KWh at the pack level. This catalyzed the market penetration of electric vehicles and made them a viable candidate for stationary energy storage. However, the rapid market expansion of LIBs raised growing concerns about the future sustainability of this technology. In particular, lithium and cobalt supplies are considered vulnerable, primarily because of the geopolitical implications of their high concentration in only a few countries. In the search for the next generation secondary batteries, known as post-lithium ion batteries, candidates that do not use rare metals have been extensively investigated in the last 10 years. Sodium-ion batteries (SIBs) attracted considerable attention thanks to the high abundance of the precursors and wide distribution of sodium on the earth's crust. As a matter of fact, as it will be pointed out during the dissertation, it is not straightforward to allocate the reduction of the price of the alkaline ion precursors to the reduction of the battery price. However, the difficulties in the supply of raw materials for LIBs, such as shortages in lithium carbonates and cobalt ores, could make lithium and cobalt-free systems, such as SIBs, attractive and cost-competitive alternatives. Compared to other, more exotic chemistries including Ca2+, Mg2+ and Al3+ batteries, SIBs are nowadays considered one as the most promising alternative to LIBs. Despite the extensive research, anode materials for SIBs still represent a serious problem for the commercial exploitation of this technology. Accordingly, the doctoral research on SIBs has been focused on anode materials. In particular, the attention was directed towards conversion oxides. Compared to intercalation materials, conversion-based ones have higher capacities but are more challenging to deal with because of the high volume variation during cycling. This challenge was addressed by material's nanostructuring and morphology control which proved to significantly reduce the pulverization of the active material. Different anode candidates have been studied during the doctoral work. Cobalt oxide nanofibers have been here explored as a first prototype for conversion materials in sodium ion batteries. The sodiation-desodiation mechanism is analyzed by means of ex situ XRD which led to a deeper understanding of the conversion reaction in SIBs. A cost-effective and environmentally benign alternative based on iron oxide is then considered. The limits of iron (III) oxide are tackled by combining the advantages of the nanostructuring and the doping with an aliovalent element. Si-doped Fe2O3 nanofibers are synthesized via an easy scalable process based on the electrospinning method. It is found that Si-addition improves the transport properties as well as induces changes in the crystal structure and morphology. In the final section of the thesis, potassium-ion batteries (KIBs) are examined as a promising alternative to sodium ion batteries. KIBs exhibit all the benefits of SIBs, with the additional advantage that graphite, can reversibly accommodate K-ions. On the positive side, Potassium manganese hexacyanoferrate (KMnHCF), has been reported to provide high operating voltages and satisfactory capacity retention. The proposed research activity presents the use of an ionic liquid based electrolyte compatible with the most promising anode and cathode for KIBs. In addition, a high-throughput optimization of the KMnHCF synthesis is reported. The selected candidates are then fully characterized, and their electrochemical properties investigated. The optimized material exhibits the highest ever reported coulombic efficiency for the KMHCF. This find, opens up the possibility of highly efficient, high energy potassium ion batteries.
Thanks to their superior energy and power density, lithium-ion batteries (LIBs) currently dominate the market of power sources for portable devices. The economy of scale and engineering optimizations have driven the cost of LIBs below the 200 $/KWh at the pack level. This catalyzed the market penetration of electric vehicles and made them a viable candidate for stationary energy storage. However, the rapid market expansion of LIBs raised growing concerns about the future sustainability of this technology. In particular, lithium and cobalt supplies are considered vulnerable, primarily because of the geopolitical implications of their high concentration in only a few countries. In the search for the next generation secondary batteries, known as post-lithium ion batteries, candidates that do not use rare metals have been extensively investigated in the last 10 years. Sodium-ion batteries (SIBs) attracted considerable attention thanks to the high abundance of the precursors and wide distribution of sodium on the earth's crust. As a matter of fact, as it will be pointed out during the dissertation, it is not straightforward to allocate the reduction of the price of the alkaline ion precursors to the reduction of the battery price. However, the difficulties in the supply of raw materials for LIBs, such as shortages in lithium carbonates and cobalt ores, could make lithium and cobalt-free systems, such as SIBs, attractive and cost-competitive alternatives. Compared to other, more exotic chemistries including Ca2+, Mg2+ and Al3+ batteries, SIBs are nowadays considered one as the most promising alternative to LIBs. Despite the extensive research, anode materials for SIBs still represent a serious problem for the commercial exploitation of this technology. Accordingly, the doctoral research on SIBs has been focused on anode materials. In particular, the attention was directed towards conversion oxides. Compared to intercalation materials, conversion-based ones have higher capacities but are more challenging to deal with because of the high volume variation during cycling. This challenge was addressed by material's nanostructuring and morphology control which proved to significantly reduce the pulverization of the active material. Different anode candidates have been studied during the doctoral work. Cobalt oxide nanofibers have been here explored as a first prototype for conversion materials in sodium ion batteries. The sodiation-desodiation mechanism is analyzed by means of ex situ XRD which led to a deeper understanding of the conversion reaction in SIBs. A cost-effective and environmentally benign alternative based on iron oxide is then considered. The limits of iron (III) oxide are tackled by combining the advantages of the nanostructuring and the doping with an aliovalent element. Si-doped Fe2O3 nanofibers are synthesized via an easy scalable process based on the electrospinning method. It is found that Si-addition improves the transport properties as well as induces changes in the crystal structure and morphology. In the final section of the thesis, potassium-ion batteries (KIBs) are examined as a promising alternative to sodium ion batteries. KIBs exhibit all the benefits of SIBs, with the additional advantage that graphite, can reversibly accommodate K-ions. On the positive side, Potassium manganese hexacyanoferrate (KMnHCF), has been reported to provide high operating voltages and satisfactory capacity retention. The proposed research activity presents the use of an ionic liquid based electrolyte compatible with the most promising anode and cathode for KIBs. In addition, a high-throughput optimization of the KMnHCF synthesis is reported. The selected candidates are then fully characterized, and their electrochemical properties investigated. The optimized material exhibits the highest ever reported coulombic efficiency for the KMHCF. This find, opens up the possibility of highly efficient, high energy potassium ion batteries.

L’utilisation massive de batteries Li-ion au cours des deux dernières décennies a poussé les chercheurs de la communauté scientifique à s’intéresser à des systèmes alternatifs basés sur des éléments abondants et peu coûteux. Parmi ces nouveaux systèmes, les batteries Na-ion sont rapidement passées de simples prototypes de laboratoire à des systèmes sur le point d’être commercialisés. Plus récemment, l’intérêt de la communauté des batteries s’est porté sur l’utilisation du potassium. Cet élément présente des atouts non négligeables pour le développement de batteries à haute densité d’énergie et de puissance en raison du faible potentiel standard du couple K+/K (vs. ESH) et des faibles énergies de désolvatation des ions K+ dans les solvants organiques usuels. Les travaux de cette thèse ont été dédiés à l’étude des mécanismes réactionnels de potassiation/dépotassiation de matériaux d’électrodes négatives. La compréhension des mécanismes qui régissent le fonctionnement des batteries est essentielle pour le développement de ces dernières. Elle permet aussi de prévenir des défaillances et de guider les recherches sur l’optimisation des matériaux d’électrode et d’électrolyte. Pour cela, deux grandes familles de matériaux d’électrodes négatives ont été étudiées au cours de cette thèse : les matériaux carbonés et plus spécifiquement le graphite, et les matériaux d’alliages à base d’éléments du bloc p de la classification périodique comme l’antimoine, le bismuth, le plomb et l’étain. L’emploi de différentes techniques de caractérisation en conditions ex situ et operando a permis d’obtenir de nouvelles informations approfondies sur les mécanismes réactionnels de ces matériaux dans les batteries K-ion. Enfin, les formulations de l’électrode et de l’électrolyte ont été identifiées comme points clés batteries pour l’optimisation des performances du graphite et des matériaux d’alliages. Même si la recherche sur les batteries K-ion reste encore au stade fondamental, ces premiers résultats sont prometteurs et laissent entrevoir un possible avenir de ces batteries pour le stockage de l’énergie d’applications stationnaires
During the last two decades, the massive use of Li-ion batteries led the scientific research community to focus on alternatives systems based on low cost and abundant elements. Among these new systems, Na-ion batteries grew rapidly from the laboratory scale to reach a real commercial application. More recently, the research community focused on the interest of potassium. This element present significant assets for the development of high energy density and high power density batteries because of the low standard potential of K+/K redox couple (vs. SHE) and low desolvation energies of K+ ions in conventional organic solvents.This thesis was focused on the electrochemical reaction mechanism of negative electrode materials in K-ion batteries. The understanding of the reaction mechanisms occurring during cycling is essential for the battery development, it allows preventing the failure and optimise the electrode materials and electrolytes.In that way, two distinct materials for negative electrodes were studied during the thesis: carbonaceous materials, more specially graphite and alloy type materials from the p block of the periodic table such as antimony, bismuth, lead and tin. The use of different characterizations in operando and ex situ conditions allowed obtaining new insights on the reaction mechanism of these electrode materials in K-ion batteries. Finally, the electrode and electrolyte formulations were identified as a key point for the performance optimisation of graphite and alloy materials.Even if the research on K-ion batteries are still in its infancy, the first results are promising and suggest a possible future solution for the energy storage for stationary applications

Potassium-selenium (K-Se) batteries are an interesting alternative to lithium-selenium (Li-Se) batteries with some notable advantages, such as a reduced cost of production and an environmentally cleaner way of production. Although the idea of K-Se batteries emerged a couple of years ago, in the last few years they have been taken seriously as a capable energy storage. Despite some disadvantages, such as a cathode volume expansion and the shuttle effect, it is considered as an interesting research field and many studies have been carried out. Herein, a carbon host to encapsulate selenium was made to try to reduce the shuttle effect. The defects in the carbon host will be controlled by H2O2 and the products will be analyzed to understand the correlation between the amount of H2O2 and the defects. After encapsulating selenium, the electrochemical proprieties will be analyzed using cyclic voltammetry, galvanostatic charge/discharge. (Additionally, the influence of the concentration of electrolyte will be studied due to the fact that it can modify the electrochemical properties of the batteries). The present project aims to determine if there is a considerable influence on the battery performance owing to the defects of the carbon hosts and the concentration of the electrolyte, and hence to find the best working condition both for K-Se batteries and for the encapsulation.

L'objectif de cette thèse est d'étudier les propriétés électrochimiques des matériaux 2D utilisés comme électrode dans les batteries et les supercondensateurs. La première partie commence par la synthèse du graphène et la préparation des films d'électrode. Une étude détaillée des propriétés électrochimiques du stockage des ions potassium a été réalisée en utilisant un aérogel à oxyde de graphène réduit (rGO) comme matériau d'électrode négative. L'influence de la nature de l'électrolyte et les méthodes de séchage utilisées ont été étudiées afin d'optimiser les performances électrochimiques du rGO lyophilisé dans les batteries potassium-ion (PIB). La spectroscopie d'impédance électrochimique (EIS) a été utilisée pour évaluer les performances de notre matériau rGO dans les PIB. Utilisé comme électrode négative, le rGO lyophilisé peut fournir une capacité élevée de 267 mAh g-1 à un taux de C/3 avec une rétention de capacité de 78% pendant 100 cycles, combinée à une capacité de taux élevé (92 mAh g-1 à 6.7 C ). Cet ensemble de résultats rend de l'aérogel rGO un matériau d'électrode prometteur pour les PIB. Ensuite, nous nous sommes concentrés sur la méthode du sel fondu (MSM) pour concevoir des matériaux aux propriétés électrochimiques améliorées pour les applications de stockage d'énergie. Avec le MSM, une quantité considérable d'oxydes ternaires Mn-based 2D and V-based 1D a été explorée puis utilisée comme cathode pour les batteries divalentes aqueuses. La nanoparticule K0.27MnO2·0.54H2O (KMO) a été utilisée comme cathode pour les batteries aqueuses Zn-ion, avec des capacités spécifiques élevées (288 mAh g-1) et une cyclabilité à long terme (rétention de capacité de 91% après 1000 cycles à 10 C) . La technique Electrochemical quartz crystal admittance (EQCM) a d'abord été réalisée pour confirmer le mécanisme de stockage de charge d'intercalation H3O+ et Zn2+ qui en résulte. De plus, le procédé au sel fondu utilisé ici a permis la préparation de 1D CaV6O16·7H2O (CVO) et utilisé en outre comme matériau de cathode dans des batteries aqueuses au Ca-ion. En conséquence, d'excellentes performances électrochimiques ont été obtenues, avec une capacité de 205 mAh g-1, une longue durée de vie (> 97% de rétention de capacité après 200 cycles à 3C) et des performances élevées (117 mAh g-1 à 12 C ) lors de réactions d'intercalation (de) intercalation des Ca-ions. Contrairement à la précédente méthode de sel fondu flash réalisée dans l'air, nous avons conçu une autre méthode de sel fondu sous atmosphère d'argon pour préparer des matériaux de carbures métalliques 2-dimmensionnels (MXene) tels que Ti3C2 (M = Ti, X = C). En jouant avec la chimie du précurseur MAX et la composition de la fonte acide de Lewis, nous généralisons cette voie de synthèse à une large gamme chimique de précurseurs MAX (A = Zn, Al, Si, Ga). Les matériaux MXene obtenus (appelés MS-MXenes) présentent des performances électrochimiques améliorées dans un électrolyte non aqueux contenant du Li+, avec une capacité de 205 mAh g-1 à 1.1 C, ce qui rend ces matériaux très prometteurs en tant qu'électrodes négatives pour les batteries Li haute puissance ou les appareils hybrides tels que les condensateurs Li-ion. Outre l'APS, un autre agent de gravure (FeCl3) a été utilisé pour dissoudre le Cu. En résumé, cette méthode permet de produire de nouveaux types de MXène difficiles voire impossibles à préparer en utilisant des méthodes de synthèse précédemment rapportées comme la gravure HF. En conséquence, il élargit encore la gamme de précurseurs de phase MAX qui peuvent être utilisés et offre des opportunités importantes pour ajuster la chimie de surface et faire du MS-MXene une électrode à haut débit dans un système non aqueux
The aim of this thesis is to study the electrochemical properties of 2D materials used as electrode in batteries and supercapacitor. The first part starts with using reduced graphene oxide (rGO) aerogel as a negative electrode material for potassium-ion batteries (PIBs). The influence of the nature of the electrolyte and the drying methods used were investigated in order to optimize the electrochemical performance of freeze-dried rGO in PIBs. Electrochemical impedance spectroscopy (EIS) were used to assess the performance of our rGO material in PIBs. rGO can deliver a high capacity of 267 mAh g-1 at C/3 rate together with 78% capacity retention during 100 cycles, combined with high rate capability (92 mAh g-1 at 6.7 C). This set of results makes rGO aerogel a promising electrode material for PIBs. Afterwards, we focused on molten salt method (MSM) to design materials with enhanced electrochemical properties for energy storage applications. With MSM, 2D K0.27MnO2·0.54H2O (KMO) and 1D CaV6O16·7H2O (CVO) have successfully prepared. KMO nanosheet has been used as cathode for aqueous Zn-ion batteries, with high specific capacities (288 mAh g-1) and long-term cyclability (91% capacity retention after 1000 cycles at 10 C). Electrochemical quartz crystal admittance (EQCM) technique was firstly performed to confirm the consequent H3O+ and Zn2+ intercalation charge storage mechanism. Additionally, CVO was further used as cathode material in aqueous Ca-ion batteries. As a result, excellent electrochemical performance was achieved, with a capacity of 205 mA h g-1, long cycle life (>97% capacity retention after 200 cycles at 3C rate) and high rate performance (117 mAh g-1 at 12 C) during Ca-ion (de)intercalation reactions. Differently from the previous flash molten salt method achieved in air, we designed another molten salt method under argon atmosphere to prepare 2D metal carbides (MXene) materials such as Ti3C2 (M=Ti, X=C). By playing with the chemistry of the MAX precursor and the Lewis acid melt composition, we generalize this synthesis route to a wide chemical range of MAX precursors (A=Zn, Al, Si, Ga). The obtained MXene materials (termed as MS-MXenes) exhibits enhanced electrochemical performance in Li+ containing non-aqueous electrolyte, with a capacity of 205 mAh g-1 at 1.1 C, making these materials highly promising as negative electrodes for high power Li batteries or hybrid devices such as Li-ion capacitors. Besides APS, another etchant (FeCl3) has been used to dissolve Cu. Furthermore, high conductive ACN-based electrolyte has been applied to improve the power performance of multi-layered MS-MXene. To sum up, this method allows producing new types of MXene that are difficult or even impossible to be prepared by using previously reported synthesis methods like HF etching. As a result, it expands further the range of MAX phase precursors that can be used and offer important opportunities for tuning the surface chemistry and make MS-MXene as high rate electrode in non-aqueous system

Three mathematical models, two of primary alkaline battery cathode discharge, and one of primary alkaline battery discharge, are developed, presented, solved and investigated in this thesis. The primary aim of this work is to improve our understanding of the complex, interrelated and nonlinear processes that occur within primary alkaline batteries during discharge. We use perturbation techniques and Laplace transforms to analyse and simplify an existing model of primary alkaline battery cathode under galvanostatic discharge. The process highlights key phenomena, and removes those phenomena that have very little effect on discharge from the model. We find that electrolyte variation within Electrolytic Manganese Dioxide (EMD) particles is negligible, but proton diffusion within EMD crystals is important. The simplification process results in a significant reduction in the number of model equations, and greatly decreases the computational overhead of the numerical simulation software. In addition, the model results based on this simplified framework compare well with available experimental data. The second model of the primary alkaline battery cathode discharge simulates step potential electrochemical spectroscopy discharges, and is used to improve our understanding of the multi-reaction nature of the reduction of EMD. We find that a single-reaction framework is able to simulate multi-reaction behaviour through the use of a nonlinear ion-ion interaction term. The third model simulates the full primary alkaline battery system, and accounts for the precipitation of zinc oxide within the separator (and other regions), and subsequent internal short circuit through this phase. It was found that an internal short circuit is created at the beginning of discharge, and this self-discharge may be exacerbated by discharging the cell intermittently. We find that using a thicker separator paper is a very effective way of minimising self-discharge behaviour. The equations describing the three models are solved numerically in MATLABR, using three pieces of numerical simulation software. They provide a flexible and powerful set of primary alkaline battery discharge prediction tools, that leverage the simplified model framework, allowing them to be easily run on a desktop PC.

Three mathematical models, two of primary alkaline battery cathode discharge, and one of primary alkaline battery discharge, are developed, presented, solved and investigated in this thesis. The primary aim of this work is to improve our understanding of the complex, interrelated and nonlinear processes that occur within primary alkaline batteries during discharge. We use perturbation techniques and Laplace transforms to analyse and simplify an existing model of primary alkaline battery cathode under galvanostatic discharge. The process highlights key phenomena, and removes those phenomena that have very little effect on discharge from the model. We find that electrolyte variation within Electrolytic Manganese Dioxide (EMD) particles is negligible, but proton diffusion within EMD crystals is important. The simplification process results in a significant reduction in the number of model equations, and greatly decreases the computational overhead of the numerical simulation software. In addition, the model results based on this simplified framework compare well with available experimental data. The second model of the primary alkaline battery cathode discharge simulates step potential electrochemical spectroscopy discharges, and is used to improve our understanding of the multi-reaction nature of the reduction of EMD. We find that a single-reaction framework is able to simulate multi-reaction behaviour through the use of a nonlinear ion-ion interaction term. The third model simulates the full primary alkaline battery system, and accounts for the precipitation of zinc oxide within the separator (and other regions), and subsequent internal short circuit through this phase. It was found that an internal short circuit is created at the beginning of discharge, and this self-discharge may be exacerbated by discharging the cell intermittently. We find that using a thicker separator paper is a very effective way of minimising self-discharge behaviour. The equations describing the three models are solved numerically in MATLABR, using three pieces of numerical simulation software. They provide a flexible and powerful set of primary alkaline battery discharge prediction tools, that leverage the simplified model framework, allowing them to be easily run on a desktop PC.

The development of the portable electronic devices, electrical vehicles, and smart grids boosts the development of electrical energy storage devices. Among them, lithium-ion batteries, a typical kind of rocking-chair batteries, have been considered as one of the most competitive choices. However, the limited lithium content in the Earth’s crust raises a concern that its cost might increase with the growing demand for electrical vehicles. Therefore, due to the relatively abundant content of sodium and potassium, sodium and potassium ion batteries are considered as alternatives with reduced cost to lithium-ion batteries. Nevertheless, the electrode materials for these two devices suffers the sluggish ion reaction kinetics and the large volume expansion due to the larger ion radiuses of sodium-ion and potassium-ion than one of lithium-ion. Constructing hollow structured materials with shorten ion diffusion length and large voids to alleviate volume expansion is considered as one of the best approaches to solve those issues of sodium and potassium ion batteries. However, the rational design and engineering to hollow structure according to the features of these two batteries remain rarely reported. Additionally, more insightful understandings of the superior electrochemical performance of hollow structured electrodes are also needed. Therefore, this thesis aims to offer some hollow structured electrode materials with rational design and engineering for sodium and potassium ion batteries with insightful understandings. Firstly, Chapter 2 summarizes the application and development trends of hollow structured electrode materials as anodes for sodium ion batteries. In this chapter, it points out that the future development of hollow structured electrode materials lays on the optimization of the confinement, the building units and the utilization of the inner voids. Therefore, the research efforts were mainly devoted in the rational design and synthesis of complex hollow structured anodes for sodium and potassium ion batteries in this thesis. The first aspect is about sodium and potassium titanates, a kind of conventional intercalation anodes for sodium and potassium ion batteries. In Chapter 3, the building units of hollow structured Na₂Ti₃O₇ were tuning by changing the solvothermal reaction solvents. It has been demonstrated that Na₂Ti₃O₇ hollow spheres assembled from nanosheets was with enhanced ion reaction kinetics by exhibiting a 33% higher charge capacity at the current density of 10 C than that of the ones assembled from nanoparticles. Furthermore, the as-prepared sample delivered a reversible capacity of over 60 mAh g⁻¹ after 1000 continuous cycles at the high rate of 50 C. In Chapter 4, dual-shell structured sodium and potassium titanate cubes with oxygen vacancies were achieved. Various spectroscopy approaches were employed to offer an atomic understanding of the oxygen vacancies. Additionally, it was revealed by density functional theory calculation that the superior electrochemical performance originates from the enhanced conductivity which is induced by oxygen vacancies. The second aspect of this thesis focuses on the synthesis of multi-shell structured anode materials for sodium and potassium ion batteries. Due to the large number of inward voids in hollow structured materials, hollow structured electrodes have been considered as with low volumetric energy density even though their high gravimetric energy density derived from their high reversible capacity. In Chapter 5, multi-shell structured Sb₂S₃ with high volumetric energy density and gravimetric energy density was synthesized. In the comparison of electrochemical performance, the multi-shell sample exhibited a higher reversible capacity than the one of pristine Sb₂S₃. Additionally, it also showed enhanced durability compared to its single-shell counterparts. These two points demonstrate the superiorities of multi-shell structured Sb₂S₃ to its single-shell counterpart and pristine Sb₂S₃. In Chapter 6, the dual-shell structured bismuth nanoboxes were synthesized and employed as anodes for potassium ion batteries. This as-prepared sample achieved an initial reversible capacity of over 300 mAh g⁻¹ and the reversible capacity maintained over 200 mAh g⁻¹ after 200 cycles under the current density of 1 C. More importantly, this dualshell structured bismuth was employed as a concept of proof to reveal the origin of the improved reversible capacity of nanostructured alloy anodes. Through various Operando synchrotron-based techniques, it was revealed that there are different origins of improved reversible capacity under low current density and high current density. Under the low current density, i.e. 0.2 C, the improved reversible capacity originates from the change of the electrochemical reaction path, in which the nanostructure offers enhanced capability to tolerate the volume expansion. Additionally, in the scenario of high current density, for instance, 2 C, the nanostructured alloy anodes provide higher surface area, resulting in more electrochemical surface reactions and, consequently, improved reversible capacity under high current density. To sum up, this thesis includes several examples of rational design and engineering hollow structured materials, such as Na₂Ti₃O₇ hollow spheres assembled from ultrathin nanosheets with N-doped carbon coating, dual-shell structured titanates with oxygen vacancies, multishell structured Sb₂S₃ with enhanced energy density, and dual-shell structured bismuth nanoboxes. Furthermore, some insightful understandings of the origins of their superior electrochemical performance were acquired through various physicochemical and electrochemical characterizations.
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering and Advanced Materials, 2019