Enhancement on the Cycling Stability of the Layered Ni-Rich Oxide Cathode by In-Situ Fabricating Nano-Thickness Cation-Mixing Layers

The layered Ni-rich oxide cathode (LiNi 0.8 Co 0.1 Mn 0.1 O 2 ) has been significantly attractive due to its large reversible capacity (200 mAh g −1 ). However, the layered Ni-rich oxide cathode suffers from a tremendous structural degradation during long-term cycling, causing the drastic rise of electrode impedance and deterioration of the capacity retention. In this paper, we develop a novel and facile approach to stabilize its structure by per-cycling of the layered Ni-rich oxide cathode at high voltage of 4.5 V (vs Li/Li + ). The nano-thickness cation-mixing layers with Fm-3m structure were in-situ formed on the layered Ni-rich oxide LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode by the surface structural transition from rhombohedral phase to cubic phase. The as-prepared LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode coated with the nano-thickness cation-mixing layers shows superior cycling life at a cutoff voltage of 4.3 V, and it keeps a capacity retention of 83% after 500 cycles, which could be attributed to that the nano-thickness cation-mixing layers stabilize the structure of LiNi 0.8 Co 0.1 Mn 0.1 O 2 during long-term cycling.