Enhanced rate performance and mitigated capacity decay of single-crystal LiNi0.8Co0.1Mn0.1O2 by the synergism of Mg doping and V2O5 coating

摘要

High nickel cathode material is considered as the most promising material in power battery. However, the material has serious structural instability and poor cycling performance. In this paper, Mg doped and V2O5 coated single crystal LiNi0.8Co0.1Mn0.1O2 (NCM811) material (labeled as NCMMg0.02@V2O5) has been success-fully synthesized. Electrochemical tests show that its first discharge specific capacity reaches 177.3 mAh/g at 1 C (1 C = 200 mA g-1) within 2.8-4.3 V, the capacity retention remains 89.1 % after 100 cycles, and the dis-charge specific capacity achieves 125.6 mAh/g at 10 C, indicating excellent electrochemical performances. Obviously, the synergism of single crystal structure, Mg doping and V2O5 coating can effectively improve struc-tural stability and Li+ diffusion coefficient, prevent surface/interface side reactions, and thus achieve the ideal cycle and rate performance.

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