Enhanced Electrochemical Performance of LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub> with SiO<sub>2</sub> Surface Coating Via Homogeneous Precipitation
Lintao Dou, Pu Hu, Chaoqun Shang, Heng Wang, Dongdong Xiao, Utkarsh Ahuja, Katerina E. Aifantis, Zhanhui Zhang, Zhiliang Huang
Abstract
Abstract Ni‐rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) has been considered as a promising cathode material for high energy density lithium‐ion batteries. However, it experiences undesirable interfacial side‐reactions with the electrolyte, which lead to a rapid capacity decay. In this work, a homogeneous precipitation method is proposed for forming a uniform silicon dioxide (SiO 2 ) coating on the NCM811 surface. The strong Si−O network provided a stable protective layer between the NCM811 active material and electrolyte to improve the electrochemical stability. As a result, the NCM811@SiO 2 cathode showed superior cycling stability (84.9 % after 100 cycles at 0.2 C) and rate capability (142.7 mA h g −1 at 5 C) compared to the pristine NCM811 cathode (56.6 % after 100 cycles, 127.9 mA h g −1 at 5 C). Moreover, the SiO 2 coating effectively suppressed voltage decay and pulverization of the NCM811 particles during long term cycling. This uniform coating technique offers a viable approach for stabilizing Ni‐rich cathode materials for high‐energy density lithium‐ion batteries.