Comprehensive insight of charge storage and ion transport in bioinspired nanostructure electrode-patterned supercapacitors by multiscale investigation

Supercapacitors with bioinspired leaves-on-branchlet hybrid carbon nanostructure-patterned electrodes show high areal capacitance and outstanding rate capability. However, the fundamental mechanisms of charge storage and ion transport in such a bioinspired supercapacitor at multiple length scales remain little explored. Herein, we develop a multi-scale model to comprehensively explore the mechanism of charge storage and ion transport, in which the finite-element-based Nernst-Planck-Poisson calculations are used for the macro-scale understanding, and molecular dynamics simulations for the atomic-scale investigation. High-throughput simulations are conducted to quantify the effect of the bioinspired structure, thermal influence, and size effect on the electrochemical performance of supercapacitors. An in-depth analysis of the simulation and experimental results demo some design advice are concluded, (1) engineering the hierarchical ordered electrode structure with sharp edges to promote charge storage and transfer, (2) designing the channel architecture with a width of ∼4 nm for avoiding size effect and improving the ion transport and storage performance. This work explores the electrochemical performance and structure properties of the devices which probably provide the designing and optimizing bases for achieving high-performance supercapacitors.