Digital twin quantifies spatial‐heterogeneity‐driven failure in fast‐charging lithium‐ion battery anodes

Abstract Fast charging of lithium‐ion batteries is critically constrained by the anode degradation processes—including Li plating, solid electrolyte interphase (SEI) formation, and stress accumulation—yet the impact of microstructural heterogeneity on these coupled degradation modes remains elusive. Here, we present a 3D digital twin framework to quantitatively reveal that phase‐level heterogeneity is a decisive driver of reaction asymmetry, side‐reaction imbalance, and stress localization. Using an experimentally informed electrode validated against measured charge profiles, we varied binder distribution, porosity, and electrode thickness to resolve their global and localized effects. Binder heterogeneity exerts only marginal impact on overall capacity in 50 μm electrodes; however, under steep gradients, its effect becomes markedly amplified—intensifying electrolyte concentration variations, disturbing Li‐ion flux, promoting uneven Li plating and SEI formation, and inducing stress hotspots. Higher porosity moderates these imbalances by improving ionic transport. In contrast, mild gradients preserve more homogeneous reaction kinetics across the electrode depth. These effects become more pronounced in thicker electrodes (83 μm), where mild gradients clearly surpass the steep one. This work identifies microstructural heterogeneity as a predictive descriptor of anode degradation under fast charging, demonstrating that regulation of heterogeneity over averaged structural metrics mitigates Li plating, SEI growth, and stress localization effects. image