Tunable Porous Electrode Architectures for Enhanced Li-Ion Storage Kinetics in Thick Electrodes

Abstract

Thick electrodes, although promising toward high-energy battery systems, suffer from restricted lithium-ion transport kinetics due to prolonged diffusion lengths and tortuous transport pathways. Despite the emerging low-tortuosity designs, capacity retention under higher current densities is still limited. Herein, we employ a modified ice-templating method to fabricate low-tortuosity porous electrodes with tunable wall thickness and channel width and systematically investigate the critical impacts of the fine structural parameters on the thick electrode electrochemistry. While the porous electrodes with thick walls show diminished capability under a C-rate larger than 1.5 C, those with thinner walls could maintain ∼70% capacity under 2.5 C. The superior capacity retention is ascribed to the fast diffusion into the thin lamellar walls compared with their thicker counterparts. This study provides deeper insights into structure-affected electrochemistry and opens up new perspective of 3D porous architectural designs for high-energy and high-power electrodes.