Improving electrochemical performance and thermal stability of LiNi0.8Co0.1Mn0.1O2 via a concentration gradient Nb doping

Unstable interface and thermal property of LiNi0.8Co0.1Mn0.1O2 have been two of the most serious obstacles to limit its practical application. Lattice doping and surface coating are two dominating methods to reinforce the property of Ni-rich cathode. In this study, Nb was as a modified element to decorate LiNi0.8Co0.1Mn0.1O2. As a result, a concentration gradient of Nb near the surface was generated after the sintering process. The Nb-doped materials could slightly suppress the H2-H3 phase transition and improve the stability of the interface. The capacity retention at 1 C rate has been enhanced more than 15% after 200 cycles, and the capacity retention is 68.7% at 10 C rate after 400 cycles. Meanwhile, the rate performance and thermal stability also have been improved.