Enhanced interfacial stability of Ni-rich cathode for Li-ion batteries towards excellent high-voltage performance

Ni-rich layered oxide LiNi0.8Co0.1Mn0.1O2 (NCM811) is one of the most promising cathode materials in advanced lithium-ion batteries. However, it suffers from poor cycling and rate capabilities due to the interfacial instability and structural degradation especially at high-voltage operation (> 4.3 V which are the key barriers for developing high-energy density cathode materials. Herein, we present an effective modification strategy toward the LiNi0.8Co0.1Mn0.1O2 through coating a rather uniform AZO protective layer on its surface, which can effectively passivate the deleterious side reactions at the cathode/electrolyte interface and improve structural stability of the layered oxides at 4.5 V high-voltage cycles. As a result, the AZOmodified Ni-rich cathode (AZO-NCM811) exhibits a great capacity retention of 86.3% after 100 cycles over 3.0-4.5 V at room temperature, which is superior than those for the pristine electrode (only 69.9%). Moreover, the AZO coating with a high ionic/electronic conductivity also endows LiNi0.8Co0.1Mn0.1O2 with a high-rate performance. This work provides a practical approach for developing the commercial application of Ni-rich cathode materials, more importantly, it may also be applied to resolve the interface instability issues occurring for other high-voltage cathode materials. (c) 2022 Elsevier B.V. All rights reserved.