Al- and Nb-Comodified Ni-Rich NCM Cathode for High-Performance Lithium-Ion Batteries

Layered cathodes with a high nickel content (Ni ≥ 80%) are viewed as the ideal choice for the future of lithium-ion batteries (LIBs) because of their high specific capacity. However, the bad cyclic and thermal stability impedes its promotion because of the increase in the nickel content. Herein, it has been demonstrated that Al- and Nb-codoped LiNi0.83Co0.12Mn0.05O2 (NCM83-NA) can improve the structural stability and inhibit the release of lattice oxygen. It is found that the introduction of Al and Nb enlarges the interlayer spacing, and Nb ions induce the formation of radially oriented primary particles, which facilitate faster lithium-ion diffusion kinetics. XRD and XPS indicate that Al and Nb codoping reduces Li+/Ni2+ cation mixing, Ni3+ with Jahn–Teller activity, and irreversible phase transition and increases the lattice oxygen content on surface. These endow materials with more stable structures and fewer surface side reactions. Consequently, NCM83-NA exhibits remarkable capacity retention (95.10% for 100 cycles at 1C), along with a notably enhanced rate capability, achieving 145.0 mA h g–1 at 5C. This work provides a hopeful approach for developing cathode materials with high performance.