Enhanced electrochemical performance of Ni-rich LiNi0.6Co0.2Mn0.2O2 coated by molecular layer deposition derived dual-functional C-Al2O3 composite coating

Uniform C-Al₂O₃ composite coating with homogeneous thickness was adopted to improve the electrochemical properties of LiNi_0.6Co_0.2Mn_0.2O₂ by the pyrolysis of molecular layer deposited alucone in argon. Compared with LiNi_0.6Co_0.2Mn_0.2O₂ coated atomic layer deposited Al₂O₃, C-Al₂O₃ coated electrode delivered high discharge capacity, good rate capability and durable cyclic stability, even at elevated temperature. Such enhanced electrochemical performance could be attributed to the synergistic effect between the amorphous Al₂O₃ and conductive carbon in the dual-functional C-Al₂O₃ composite coating, resulting in the improved structural stability and electrochemical kinetics of LiNi_0.6Co_0.2Mn_0.2O₂ cathode. The network of carbon in C-Al₂O₃ composite coating supplied high electrical conductivity, and lowers the charge transfer resistance on the surface of electrode. Meanwhile, the uniform amorphous Al₂O₃ with its flexible structure improved the structural stability of cathode and favored the diffusion of Li⁺ ions.