Chemical‐Mechanical Robustness of Single‐Crystalline Ni‐Rich Cathode Enabled by Surface Atomic Arrangement Control

Abstract

AbstractLayered transition metal oxide cathodes have been one of the dominant cathodes for lithium‐ion batteries with efficient Li+ intercalation chemistry. However, limited by the weak layered interaction and unstable surface, mechanical and chemical failure plagues their electrochemical performance, especially for Ni‐rich cathodes. Here, adopting a simultaneous elemental‐structural atomic arrangement control based on the intrinsic Ni−Co−Mn system, the surface role is intensively investigated. Within the invariant oxygen sublattice of the crystal, a robust surface with the synergistic concentration gradient and layered‐spinel intertwined structure is constructed on the model single‐crystalline Ni‐rich cathode. With mechanical strain dissipation and chemical erosion suppression, the cathode exhibits an impressive capacity retention of 82 % even at the harsh 60 °C after 150 cycles at 1 C. This work highlights the coupling effect of structure and composition on the chemical‐mechanical properties, and the concept will spur more researches on the cathodes that share the same sublattice.