Dry‐Processed Dual‐Layer Thick Cathodes With Distinct Ni Compositions to Mitigate Degradation in Lithium‐Ion Batteries

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 LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) and LiNi 0.6 Co 0.2 Mn 0.2 O 2 (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.