IONACES · Understanding ion transport in nanoporous carbons; application to energy storage and sustainable development

Electrochemical Double-Layer Capacitors Electrochemical Capacitors (EDLC) are promising devices for clean energy storage applications. In EDLCs, the charges are stored electrostatically at the electrolyte / electrode interface, which confers them high power and cycling capabilities. Until recently, it was believed that charge storage in porous carbon EDLC electrodes could be achieved only if the pore size of the carbon was larger than the electrolyte ions with their solvation shells. Using Carbides Derived Carbons (CDCs) which have controlled pore sizes between 0.6 nm and 1.1 nm, we recently demonstrated that high capacitive performances could be obtained when the pore size is smaller than the solvated ion size.The origin of this capacitance increase is still unclear despite important modelling efforts achieved by many research groups. Using our fine-tuned, controlled pore size CDCs carbons with narrow pore size distribution, we propose here an integrated approach combining the use of experimental electrochemical methods (EQCM, EIS, CV…) and in-situ analytical techniques (NMR, XRD), to computational modelling (Molecular Dynamics, Monte Carlo and Reverse Monte Carlo methods) to elucidate the ion transport and adsorption mechanisms inside nanopores.A direct application of this fundamental approach concerns the energy storage with supercapacitors. Thanks to the unique features offered by the CDCs, we propose to develop the next generation of high-energy density micro-supercapacitors from bulk CDC films.The evidence of the increase of the capacitive ion adsorption associated with ion partial desolvation in micropores is also of great interest in different areas such as water desalination. CDCs, which have demonstrated volumetric capacitance improvement of 100% compared to activated carbon for supercapacitor application, are appealing materials for water desalination applications, which will be the last part of the project.