Enhanced electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode materials at elevated temperature by Zr doping
In order to ameliorate the severe capacity fading of LiNi0.5Co0.2Mn0.3O2 cathode materials at elevated temperatures, a Zr-doping strategy was performed via a solid-state method, and the influence of the doping content on the structural and electrochemical properties of LiNi0.5Co0.2Mn0.3O2 was studied. The results indicate that the Li+/Ni2+ cation mixing can be reduced and the electrochemical performance, especially the hightemperature cycling performance, can be improved when the doping content of zirconium is 0.01. After 95 cycles, the capacity retention of Li(Ni0.5Co0.2Mn0.3)0.99Zr0.01O2 is 92.13% at 1C between 3.0 and 4.3 V, which is higher than that of the LiNi0.5Co0.2Mn0.3O2 (87.61%). When cycling at 55 ℃, Li(Ni0.5Co0.2Mn0.3)0.99Zr0.01O2 exhibits a capacity retention of 82.96% after 115 cycles at 1C, while that of the bare sample remains at only 67.63%. Therefore, a small amount of zirconium doping is notably beneficial to the electrochemical performance of LiNi0.5Co0.2Mn0.3O2 at elevated temperatures.