Al Substitution Induced Differences in Materials Structure and Electrochemical Performance of Ni-Rich Layered Cathodes for Lithium-Ion Batteries

Ni-rich layered oxides are very promising high energy density cathodes for lithium-ion batteries. A small amount of Ni, Co, and Mn is substituted by Al to study the structural evolution, electrochemical behaviors, and properties of Ni-rich cathodes. Neutron diffraction results demonstrate that Al substitution for Ni, Co, and Mn results in remarkable differences in materials structure and reduced the cation mixing with different degrees. The distinct differences in electrochemistry including rate capability, long-term cycling stability, average operating voltage, and polarization effect are systemically discussed, which can be ascribed to the material structural evolution. In contrast, LiNi0.6Co0.2Mn0.15Al 0.05O2 can deliver a very high specific capacity of 120 mAh g–1 at 10C and an 82.4% cycling stability after prolonged 500 cycles at 2C. This study offers a fundamental insight into optimizing the materials structure and composition of layered oxide cathodes with higher Ni content for lithium-ion batteries.