High performance and low air sensitivity for Ni-rich Co-free cathode materials

Abstract

The Ni-rich layered LiNi0.75Mn0.25O2 (NM) is mixed with LiMn2O4(LMO) for calcination, which can reduce the residual lithium on the surface of NM, decrease the lithium‑nickel mixing, and improve the structural stability of the material's surface, as well as make the material less sensitive to H2O and CO2 in the air. The discharge capacity of NM modified by adding 2 wt% LMO was 155.67 mAh g- 1 after 200 cycles (1C, 3.0–4.3 V), with a capacity retention rate of 78.44%. The results show that the thermal stability, cycling reversibility, and storage performance of the hybrid electrode are significantly improved, compared with those of the pristine NM, and the addition of the appropriate amount of LMO makes the comprehensive performance of the hybrid electrode more superior.