Synergistic construction of uniform LiAlO2 coating on LiNi0.8Co0.1Mn0.1O2 cathode materials by acid etching and polyvinylpyrrolidone cross-linking approaches for high-performance Li-ion batteries

A uniform and conductive LiAlO2 coating on the LiNi0.8Co0.1Mn0.1O2 cathode material was successfully constructed by the synergistic effects of acid etching and polyvinylpyrrolidone (PVP) cross-linking approaches. Hydrolysis of Al sources (Al(NO3)3) generates H+ ions to etch the inert surfaces of hydroxide precursors, which leaves highly active sites exposed on the Ni0.8Co0.1Mn0.1(OH)2 surfaces for subsequent coating. Furthermore, PVP polymeric chains act as cross-linkers to anchor Al(OH)3 onto the highly active Ni0.8Co0.1Mn0.1(OH)2 surfaces for the formation of uniform LiAlO2 coating layers after chemical lithiation of calcination. The synergistically constructed LiAlO2 coating layers could effectively reduce the gas production and improve the cycling stability of the LiNi0.8Co0.1Mn0.1O2 cathode materials with a high reversible capacity of 212.0 mAh g-1 at 0.1C for the initial cycle and 172.3 mAh g-1 at 1C for the 200th cycle.