Electrochemical performance research of Mg ion doped LiMnPO₄/C

LiMn1-xMgxPO4/C(x=0, 0.01, 0.04, 0.05, 0.1) were synthesized by using wet-ballmilling and solid-state calcining with phenolic resin as the carbon source. All samples are single phase with a similar morphology, but the cation substitution results in a crystal lattice shrink because of the smaller ionic radii of Mg2+, the particles are small and homogeneous. Charge/discharge and EIS measurement shows that the Mg substitution leads to a significantly increased reversible capacity due to the enhanced electrochemical kinetics. LiMn0.96-Mg0.04PO4/C calcined at 600°C has a discharge capacity of 144 mAh/g at 0.05 C. When charging-discharging by CC-CV-CC mode at high rates, LiMn0.96Mg0.04PO4/C composite exhibits a good cyclability and rate capability.