Both specific energy and power densities have to be increased and improving the volumetric capacitance of supercapacitors, which is one of the limiting factors of today’s stationary applications, is essential . In order to meet those requirements, solid state chemistry is an extremely powerful tool to design new materials. Our strategy was based on the study of materials that are electrochemically active in aqueous media, with transition metals and/or high density elements, with the possibility to use low-temperature synthesis methods in order to get nanosized particles with high specific surface areas, and the possibility to have several redox couples that could be involved in the charge storage mechanism. Among the studied materials, our interest has focused on different materials such as transition metal oxides (MnO2, Fe3O4,…) and polycationic oxides MWO4 (M=Fe, Mn, Co,…) . Synthesis conditions and materials characterizations of the electrodes and also of full devices will be detailed in the presentation, highlighting the crucial role of the electroactive elements, the crystallographic structure, and the morphology of the synthesized materials on their electrochemical performance.
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