Optimized structure stability and cycling performance of LiNi0.8Co0.1Mn0.1O2 through homogeneous nano-thickness Al2O3 coating br

LiNi0.8Co0.1Mn0.1O2 (NCM811), as a high specific capacity cathode, is widely known and draws extensive attention. However, the short cycle of NCM811 induced by severe cracks and reversible structural degradation is a critical challenge for the commercialization. Here, homogeneous nano-thickness Al2O3 coating that is directly deposited on NCM811 composite electrode by atomic layer deposition (ALD). The electrochemical performance of NCM811 cathode can be tailored by the thickness of Al2O3 coating precisely controlled at sub-nanometer scale. The optimal thickness of Al2O3 coating for maximized electrochemical performance of NCM811 is grown via 10 ALD cycles, which can deliver a capacity retention of 93.81% after 100 cycle under cut-off voltage of 4.3 V, compared to 78.37% of pristine NCM811 cathode. The improved electrochemical performance is attributed to the appropriate Al2O3 coating layer that can prevent the side reaction between cathode and electrolyte, maintain the original morphologies of the cathode particles, alleviate the stress changes, and suppress the formation of microcracks upon cyclings. This work provides an effective technique for high-quality oxide coating with precise thickness controlled at atomic scale for Ni-rich NCM cathode material with improved electrochemical performance.

Automated summary

This study introduces a method to deposit Al2O3 coating on NCM811 cathode material through atomic layer deposition technique, which can improve its electrochemical performance and prolong cycling life.