Ultra-high nickel cobalt-free layered cathode material NM90 for power batteries modified collaboratively by La2O3 coating and La3+ doping

Due to the urgency of developing high energy density cathode materials in power batteries, as well as the high price and environmental unfriendliness of cobalt, researchers are working on ultra-high nickel low cobalt and ultra-high nickel cobalt-free layered cathode materials. However, the poor cyclic stability and rate performance of this material resulted from structural instability and severe surface/interface side reactions during cycling seriously hinder its practical application. In this paper, LiNi 0.9 Mn 0.1 O 2 (NM90) cathode material is modified by La 2 O 3 coating, and La 3+ doping caused by thermal diffusion is achieved simultaneously. The synergistic enhancement of the two modifications can effectively improve the layered structure and reduce surface/interface side reactions. The dual-modified material shows good structural stability, the La 2 O 3 coating does not fall off and the active material does not appear fragmentation and collapse after 100 cycles. At the same time, the dual-modified material also shows excellent electrochemical performance, with a capacity retention of 83.19% after 100 cycles at 1 C and a reversible capacity of 129.9 mAh g −1 at 10 C. The electrochemical mechanism reveals that the dual-modified material effectively reduces the charge transfer resistance and greatly increases the Li + diffusion coefficient. It will provide useful reference and technical support for the research of other electrode materials. Graphical abstract The NM90 and La 2 O 3 -coated NM90 particles have similar spherical morphology and are formed by the agglomeration of many primary particles; the surface of NM90 material is evenly coated by La 2 O 3 and No obvious boundary between La 2 O 3 and NM90 materials is found; LiNi 0.9 Mn 0.1 O 2 cathode material coated by 1wt% La 2 O 3 has the best cycle stability.