The Synthesis of LiMnxFe1−xPO4/C Cathode Material through Solvothermal Jointed with Solid-State Reaction

Abstract

LiMn<i>_x</i>Fe_1-<i>x</i>PO₄/C material has been synthesized through a facile solid-state reaction under the condition of carbon coating, using solvothermal-prepared LiMnPO₄ and LiFePO₄ as precursors and sucrose as a carbon resource. XRD and element distribution analysis reveal completed solid-state reaction of precursors. LiMn<i>_x</i>Fe_1-<i>x</i>PO₄/C composites inherit the morphology of precursors after heat treatment without obvious agglomeration and size increase. LiMn<i>_x</i>Fe_1-<i>x</i>PO₄ solid solution forms at low temperature around 350 °C, and Mn²⁺/Fe²⁺ diffuse completely within 1 h at 650 °C. The LiMn<i>_x</i>Fe_1-<i>x</i>PO₄/C (<i>x</i> < 0.8) composite exhibits a high-discharge capacity of over 120 mAh·g^-1 (500 Wh·kg^-1) at low C-rates. This paves a way to synthesize the crystal-optimized LiMn<i>_x</i>Fe_1-<i>x</i>PO₄/C materials for high performance Li-ion batteries.