Gradient-Matched Microstructural Engineering for Fast-Charging, Damage-Tolerant Thick Electrodes of Lithium-Ion Batteries

Gradient microstructure design has emerged as a promising strategy for developing high areal loading thick electrode batteries with both fast-charging performance and mechanical integrity. However, it has largely been explored through trial-and-error approaches. In this study, a universal matching concept is introduced, wherein electrode microstructures—specifically the conductive network, porosity, and particle size—are gradiently distributed to align with the intrinsic gradients of electron, ion, and reaction-driven fluxes, respectively. The electro-chemo-mechanical coupled modeling and simulations validate that multi-gradient matched structures in thick electrodes lead to a synergistic enhancement of both fast-charging performance and mechanical resilience, consistent with experimental observations. This study demonstrates how the gradient-matched structure fosters collaborative electron/ion and reaction transport, optimizing the balance between these processes and further mitigating concentration polarization. The findings provide a comprehensive design principle for gradient architecture that enables fast-charging, damage-tolerant thick electrodes.