Relation between Charging Times and Storage Properties of Nanoporous Supercapacitors

An optimal combination of power and energy characteristics is beneficial for the further progress of supercapacitors-based technologies. We develop a nanoscale dynamic electrolyte model, which describes both static capacitance and the time-dependent charging process, including the initial square-root dependency and two subsequent exponential trends. The observed charging time corresponds to one of the relaxation times of the exponential regimes and significantly depends on the pore size. Additionally, we find analytical expressions providing relations of the time scales to the electrode's parameters, applied potential, and the final state of the confined electrolyte. Our numerical results for the charging regimes agree with published computer simulations, and estimations of the charging times coincide with the experimental values.

Automated summary

This study develops a nanoscale dynamic electrolyte model to describe the static capacitance and time-dependent charging process of supercapacitors. It finds that the charging time is significantly dependent on the pore size and provides analytical expressions for the relations between time scales and electrode parameters, applied potential, and the final state of the confined electrolyte.