Improved cycle performance of nitrogen and phosphorus co-doped carbon coatings on lithium nickel cobalt aluminum oxide battery material

Nitrogen-phosphorus co-doped nanoscale carbon coating (N/P-C) was constructed on the surface of LiNi0.8Co0.15Al0.05O2 (NCA). The coated material showed a shell-core structure, the core layer was NCA, the shell layer was N/P-C, and the coating was evenly distributed on the surface of the material. The coating improves electron transport path in the structure of NCA, increases conductivity, protects the electrode material, suppresses dissolution of the metal ions and improves stability. In this experiment, aniline (ani) was used as the carbon source and the nitrogen source, and phytic acid was used as the carbon source and the phosphorus source. They were mixed at a mass ratio of m (NCA)/m (C) = 100:0.5, 100:1.0 and 100:2.0, respectively, and then annealed to form a uniform coating. By comparison, it can be concluded that the coating has the best electrochemical performance when the coating mass fraction is 1.0%. At the current density of 1 C, the capacity retention rate was 90.7% after 200 cycles, higher than uncoated material (70%).