Steady-state interface construction of high-voltage nickel-rich lithium-ion battery cathodes by low-content LixCoO2 surface modification engineering.

The nickel-rich layered ternary cathode material has gained widespread interest for its high theoretical specific capacity. However, the inferior charge/discharge cycle, because of increased side reactions at high cut-off voltages, severely limits its application in industrial applications. Improving the electrochemical performance of LiNi_0.8Co_0.1Mn_0.1O₂ by forming a protective layer without changing the structural characteristics of the electrode material itself is considered to be the most effective method. In this work, we constructed a Li_xCoO₂ crystalline cladding layer through an extremely effortless and very easy-to-industrialize method. These coating materials significantly improved the cycling stability of NCM811 at 4.8 V ultra-high cut-off voltage. Results of characterization showed that after 100 cycles at 1 C (2.8–4.8 V), the 1.0 wt% modified NCM811 and pristine NCM811 show a retention of 77% and 53%, respectively. This is attributable to the fact that the coating material can effectively mitigate the interfacial side reactions to protect the active electrode material, further enhance the kinetic transport properties of Li⁺ across the interface, and reduce the degradation of the bulk structure. Based on these results, we think that the Li_xCoO₂ crystalline cladding layer is a useful way to very significantly elevate the properties of nickel-rich lithium metal oxide electrode materials. [ABSTRACT FROM AUTHOR]