Synergistic effect of Na and B co-doping on the electrochemical properties of LiNi0.865Co0.095Al0.04O2 cathode materials for Li-ion batteries

The high-nickel cathode material LiNi 0.865 Co 0.095 Al 0.04 O 2 (NCA) has garnered significant attention due to its high energy density and cost-effectiveness in production. However, this material is also prone to rapid capacity degradation, primarily due to phase transitions occurring during the redox process. In this paper, the co-modification with Na and B cations is employed to stabilize the lattice structure and enhance the electrochemical performance of the NCA material. It can be found that the incorporation of Na and B cations in the lattice can reduce cation mixing, expand the Li-layer spacing and improve crystal stability, thereby increasing the specific capacity and cyclic stability of the NCA material. Specifically, the co-doped NCA-2 sample exhibits a specific capacity of 202.1 mAh/g at 0.1 C and maintains a capacity retention of 78.75 % at 1 C after 300 cycles, representing a substantial improvement over the pristine material (187.2 mAh/g and 61.68 % capacity retention). Moreover, at a current density of 10 C, the co-doped NCA-2 sample demonstrates a high specific capacity of 133.9 mAh/g, compared to 110.1 mAh/g for the pristine material. The Na/B co-doping strategy presented in this study offers a straightforward method to improve the cyclability and rate behavior of cathode materials, highlighting its potential for commercial applications.