PVP-assisted solvothermal synthesis of LiMn0.8Fe0.2PO4/C nanorods as cathode material for lithium ion batteries

LiMn0.8Fe0.2PO4/C rectangular prism nanorods with a short b-axis are successfully synthesized via solvothermal method by means of the in-situ polymerization of resorcinol–formaldehyde followed with further annealing process. In this process, PVP has significant effect on the nanorod morphology. Physicochemical characterizations and electrochemical measurements results demonstrate that the short b-axis of nanorod can contribute to shortening the lithium ion diffusion distance. Relatively thin and uniform carbon layers can improve the electronic conductivity. Furthermore, LiMn0.8Fe0.2PO4/C nanorod delivers a reversible discharge capacity of 140 mA h g−1 at 0.1 C, and remarkable rate capability is exhibited with 78.6% capacity retention at a 4 C rate. Meanwhile, it shows stable cycling stability and capacity retention of 98.1% is still maintained after 100 cycles at 1 C. The excellent electrochemical properties can be attributed to the structure superiority of nanorod.