Effect of transition metals doping on the structural and electronic properties of LiMnPO4: spin density functional investigation

Spin density functional theory using the Perdew-Burke-Ernzerhof generalized gradient approximation (GGA + U) is used to analyze the electronic properties and improvement in electronic conductivity of LiMnPO4 doped with various transition metals. The dopants modify the lattice constants and volumes. The total and partial density of states highlight that the formation of impurity states is induced inside the edge of the conduction bands, thus reducing the band gap of LiMnPO4 and improving the electro-conductive properties. Transition metal doping demonstrates the enhancement of lithium insertion potential with respect to LiMnPO4, showing the advance in the energy storage density. Cr doping in LiMnPO4 demonstrates the enhancement of the cathode performance because of the volumetric expansion, narrow band gap and high Li insertion potential. Finally, these results convey a valuable agenda for the future optimization of transition-metal doped LiMnPO4 cathode materials for next-generation lithium batteries.