A Mo/PANI co-modified ultra-high nickel NCM9622 cathode composite with excellent cycle stability and high-rate performance for power batteries

Abstract

Ultra-high nickel layered cathode materials with very high specific capacity are the future direction of power battery development, but they also face many challenges such as poor cycling stability and high-rate performance. In this paper, we adopt an effective Mo/PANI co-modification strategy on a LiNi_0.96Co_0.02Mn_0.02O₂ (NCM9622) cathode material and achieve excellent electrochemical performances. The optimized modified NCM9622 cathode material can reach 209.3 mA h g⁻¹ with an upper cut-off voltage of 4.4 V at 1C, and its capacity retention reaches 95.7% after 100 cycles, which exceeds that of similar materials reported so far. In addition, the material also has outstanding high-rate properties, and its discharge specific capacity reaches 167.1 mA h g⁻¹ at 10C. The excellent electrochemical properties are well demonstrated by the results of Li⁺ migration barriers and electronic density of states (DOS) calculated by density functional theory (DFT). We believe that the cooperative modification strategy of high-valence ion doping and conductive polymer coating will provide technical support for solving the key problems of ultra-high nickel cathode materials.