Effect of FePO4 coating on structure and electrochemical performance of Li1.2Ni0.13Co0.13Mn0.54O2 as cathode material for Li-ion batteries

In this work, Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 was prepared by the sol–gel method and coated with FePO 4 . The experimental results show that the material surface is uniformly coated with FePO 4 . A small amount of coating will not change the layered structure of the material. Among them, the material with 5% FePO 4 coating has the best performance. The first charge and discharge specific capacity at 0.1 C current density is 324.4 mAh g −1 and 280.4 mAh g −1 , respectively. And the first coulomb efficiency is 86.4%, which is significantly higher than 75.6% of the pristine material. The improvement of the first charge–discharge performance of the coating material is due to the decrease of discharge voltage plateau and the redox of FePO 4 with electrochemical activity. When the FePO 4 coating content is 5%, the cycling performance of the material at 0.2 C current density is the best. After 100 cycles, the capacity decays from 268.4 to 232.9 mAh g −1 , and the capacity retention rate is 86.78%, which is higher than 60.58% of the pristine sample. The discharge specific capacity of 5% coated material at 5 C rate is 134.8 mAh g −1 , which is higher than 95.3 mAh g −1 of the pristine material. Graphical