Mg-doped LiMnPO4/C cathode materials for enhanced lithium storage performance

Mg-doped LiMn1-xMgxPO4/C (x = 0, 0.01, 0.03 and 0.05) compounds were synthesised using a ball-milling-assisted solid-state reaction. The influence of the Mg-doping on the structure, morphology and electrochemical performance of LiMnPO4 were systematically investigated. The XRD results demonstrated that the obtained LiMn1-xMgxPO4/C products possess a single olivine-type structure. Particularly, the desired LiMn1-xMgxPO4/C compounds exhibited the enhanced specific capacity and cycling performance over the undoped LiMnPO4/C. An initial capacity of 131.1 mAh/g was achieved for the LiMn0.97Mg0.03PO4/C composite, and it retained 116.9 mAh/g over 30 cycles at a charge-discharge rate of 0.05 C. It can be expected that the Mg-doped LiMnPO4/C is a kind of promising cathode materials for high-performance lithium-ion batteries.