Pressure-Resistant Polycrystalline Ni-Rich Layered Cathodes for High-Performance All-Solid-State Lithium Batteries

All-solid-state lithium batteries (ASSLBs) require high operating pressures for efficient Li-ion transport, yet the impact of the assembly pressure on cathode integrity remains unclear. We address this through designer morphology-engineered polycrystalline Ni-rich LiNi0.90Co0.05Mn0.05O2 (DMP-NCM90) with refined primary particles, achieving unprecedented pressure resistance (244.9 MPa, 2.4× higher than conventional NCM90). This robustness prevents crack formation during high-pressure cell assembly and subsequent cycling, thereby avoiding performance degradation caused by interfacial detachment and secondary particle fracture. When paired with a Li–In anode in ASSLBs, the DMP-NCM90 full cell delivers an initial capacity of 201.1 mAh g–1 with an outstanding capacity retention of 69% after 1000 cycles, significantly outperforming the reference cathode (34% retention). Remarkably, postcycling analysis reveals the DMP-NCM90 electrode maintains excellent interfacial contact with minimal porosity (2.96%), demonstrating exceptional mechanical–electrochemical stability. Our findings establish a clear relationship between cathode pressure tolerance and long-term ASSLB performance, providing crucial design principles for developing durable solid-state battery systems.