Decoupling Ion-Electron Transport in Thick Solid-State Battery Electrodes

Thick electrode architecture, promising better energy storage performance in solid-state batteries (SSBs), requires an optimized ion permeation network design. Unfortunately, ignoring the complex ion-electron coupling, the single ion diffusion optimized array electrodes have an unbalanced energy/power density issue. Hence, a vascularized electrode with a homogeneous electronic/ionic transport network is proposed. By decoupling the ion-electron transport process, a multifactor correlated thick electrode design criterion is established. The competitive effects of space and mass of the active/inactive components are considered for architecture optimization and performance improvement. The optimized LiFeO₄ (LFP) electrode ensures high-rate operation at ultrahigh areal capacity, achieving power densities exceeding 1600 W kg^-1. The solid-state pouch cells exhibit long-term cyclability, providing high energy/power density (approximately 200 Wh kg^-1, 687 W kg^-1) and thermal/mechanical tolerance. Furthermore, bipolar stacking enables pouch cells to have a high voltage and volumetric energy density. This work lays a solid foundation for the commercial application of thick electrodes, illuminating the future of industrial solid-state batteries.