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

• AZO-decorated LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode exhibits outstanding cell performance when operating at 4.5 V. • The stability of the interface and structure for AZO-modified cathode is significantly improved. • The AZO-coating endow LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode with a high ionic/electronic conductivity. • The deleterious parasitic reactions on the electrode surface can be effectively restrained after AZO modification. Ni-rich layered oxide LiNi 0.8 Co 0.1 Mn 0.1 O 2 (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 LiNi 0.8 Co 0.1 Mn 0.1 O 2 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 AZO-modified 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 LiNi 0.8 Co 0.1 Mn 0.1 O 2 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.