<font>LiFe</font>_1-x<font>Mn</font>_x<font>PO</font>₄/<font>C</font> COMPOSITE AS CATHODE MATERIAL FOR LITHIUM ION BATTERY

Abstract

LiFe 1-x Mn x PO 4 / C composites were prepared as cathode material for lithium ion battery via solid-state reaction and using glucose as reducing agent and carbon source. The crystal structure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The resultant samples were pure olivine compounds with an orthorhombic structure. Their electrochemical performance was studied by galvanostatic charge–discharge test and cyclic voltammetry. The results showed that the sample LiFe 0.8 Mn 0.2 PO 4 /C with an average particle size of 400 nm exhibited the largest discharge capacity of 150 mAh g -1 , excellent reversibility of charge–discharge and high capacity retention of 97% after a 50-cycle CV scanning. The improved electrical conductivity corresponding to the fine carbon layer around the LiFe 0.8 Mn 0.2 PO 4 individual particle can be responsible for all these excellent electrochemical performance.