A deep understanding of ion desolvation in microporous electrodes is
helpful for achieving efficient energy storage. Herein, we evaluate the
contribution of ion desolvation to electrochemical performance of
microporous electrodes with a proposed multiscale approach. By
integrating the molecular version with the simple version of classical
density functional theory, we first determine the solvation diameters of
ions in confined molecular solvent, and then predict the capacitances of
microporous electrodes through a solvation-diameter-dependent
coarse-grained model. We find that the solvation diameter displays an
oscillatory decline as decreasing the pore size of nanoslit, and upon
this relation in combination with the pore size distribution of
microporous electrode we give satisfactory predictions of the
capacitances of practical electrodes compared with experimental
measurements. This work not only provides a feasible multiscale tool for
predicting the capacitances of microporous electrodes involving liquid
electrolytes, but also casts insights for the design and preparation of
high-performance supercapacitors.