Improving the electrochemical performance of lithium-rich oxide layer material with Mg and La co-doping

Voltage and capacity decay during the cycle, which mainly attributes to the instability of crystal structure, have always been a barrier to the lithium-rich oxide layer material's commercialization. In this work, the combined effect of Mg and La co-doping on the electrochemical performance of lithium-rich oxide layer material has been investigated. Owning to the Mg and La co-doping that are doped in Li-sites and Mn-sites in transition metal (TM) layer, Li(Li0.18Mn0.52Co0.13Ni0.13La0.02Mg0.02)O2 exhibits excellent structure stability and electrochemical performance. The electrochemical results show that Li(Li0.18Mn0.52Co0.13Ni0.13La0.02Mg0.02)O2 delivers a relatively high discharge specific capacity 231.9 mAh g−1 at 0.5 C. After 150 cycles, about 86.16% of the capacity is maintained and the discharge voltage fading is mitigated to 0.3988 V. When the current density reaches to the 5 C, Li(Li0.18Mn0.52Co0.13Ni0.13La0.02Mg0.02)O2 still delivers a high discharge specific capacity of 121.1 mAh g−1. In conclusion, the co-doping of TM-site and Li-site can be a promising method for improving the structure stability and electrochemical performance of lithium-rich oxide layer material. [Display omitted] •Mg-doping can retard the excessive deintercalation of Li+.•La-doping can improve the structure stability and migration rate of Li+.•Mg & La co-doping possesses the advantages of Mg-doping and La-doping.