Abstract

Thick cathodes are essential for high-energy-density lithium-ion batteries; however, their practical implementation is limited by the depth-dependent reaction heterogeneity and the resulting structural and interfacial degradation under high-loading conditions. Here, we developed dry-processed dual-layer (DL) thick cathodes by combining LiNi0.8Co0.1Mn0.1O2 (NCM811) and LiNi0.6Co0.2Mn0.2O2 (NCM622) and systematically varying their layer sequence at a fixed areal capacity of 8 mAh cm−2. Among the tested architectures, DL-811/622(4/4), in which an NCM811 layer with an areal capacity of 4 mAh cm−2 was positioned on the current-collector side and an NCM622 layer with an areal capacity of 4 mAh cm−2 was positioned on the separator side, delivered the best overall performance. Compared with the reversed architecture, the 1C/0.2C capacity retention increased from 27.3% to 41.9%, and the cycling capacity retention increased from 50.4% to 83.5%. Postmortem analyses showed that this configuration suppressed NCM811 microcracking, Ni crossover, nonuniform Li redistribution, structural disorder, and cathode–electrolyte interphase growth. Digital-twin simulations further showed that positioning NCM811 on the current-collector side reduced local overdelithiation and stress concentration in the high-Ni phase. These results show that controlling the depth-wise placement of the high-Ni phase is critical for stabilizing dry-processed thick cathodes under high-loading conditions.