Unveiling the enhancing mechanism of cycling stability of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2-x F x cathode materials

Lithium-rich manganese-based material is one of the most promising cathode materials for Li ion battery due to its low cost and high specific capacity. However, the irreversible evolution of oxygen and migration of transition metals (TM) restricts its widely practical application. In this paper, F-doped Li 1.2 [Mn 0.54 Ni 0.13 Co 0.13 ]O 2 was prepared by co-precipitation and high temperature solid-state reaction method. The effects of F-doping on the electrochemical properties of Li 1.2 [Mn 0.54 Ni 0.13 Co 0.13 ]O 2 during the charge–discharge procedure were investigated. Results show that Li 1.2 [Mn 0.54 Ni 0.13 Co 0.13 ]O 1.95 F 0.05 sample has the excellent cycling stability; the discharge-specific capacity reaches 182.9 mAh g −1 after 200 cycles, with a capacity retention rate of 87.9%, which was much higher than that of the original sample (133.2 mAh g −1 and 77.5%). The relevant properties proved that F-doping can inhibit the irreversible evolution of oxygen, alleviate the structural degradation of the material, and further alleviate the dissolution of transition metals by suppressing the interfacial side reactions. This result provides reference for the practical application of Li-rich cathode materials.