Influence of V-Substitution on the Electrochemical Performance of LiNi0.90Co0.05Mn0.05O2

Bulky substitutions with transition-metal elements are widely used to improve the comprehensive performance of ternary oxide cathodes. As the Ni content increases to 90% and higher, the modification strategies should be reconsidered since the regular remedies have difficulty addressing their inherent drawbacks. Here, we propose the influence of vanadium substitution, which is rarely used in bulky substitution. This modification obviously improves the durability of LiNi0.90Co0.05Mn0.05O2 at high rate and slightly lowers its reversible capacity. As the best sample, the 2% V-substituted sample delivers 174.4 mA h/g in the first cycle and still maintains 72.5% in the 200th cycle under 5 C, respectively. This variation should be dependent on the abated Δc during operation and the enhanced Li+ diffusion coefficient. Furthermore, the ameliorated mechanical behavior is further proved by the intact particles of the 2% V-substituted sample after 200 cycles. Our results demonstrate that vanadium substitution should be one of the potential strategies to modify Ni-rich materials due to their complementarity.