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

Angew Chem Int Ed Engl. 2023 May 22;62(22):e202302170. doi: 10.1002/anie.202302170. Epub 2023 Apr 25.

Abstract

Layered 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.

Keywords: Atomic Arrangement; Chemical-Mechanical Property; Lithium-Ion Battery; Nickel-Rich Cathode; Surface Robustness.