Charging dynamics of a supercapacitor: a multiple-stack model studied by Poisson-Nernst-Planck equations and equivalent RC circuits.

Abstract

In the last few years supercapacitors, high performance electricity storage systems, have attracted the attention of researchers due to the fundamental interest and wide range of applications. Carbon-based electrodes provide a larger capacitance thanks to their large surface area which has already been widely studied for the case of a single-plate capacitor. Hence, we have developed a new model trying to mimic the behaviour of a supercapacitor by a multiple-stack electrode-electrolyte system. We first analyse it solving Poisson-Nernst-Planck equations and by an equivalent equilibrium circuit model, with a sudden switching-on of the potential. Then, we go a step further in the circuit model to give solution for any time-dependent potential, though just a triangular periodic one is chosen to be studied within the thesis. Finally, we also make some simulations varying the geometry of the model.