Improved of cathode performance of LiFePO4/C composite using different carboxylic acids as carbon sources for lithium-ion batteries

Among the several materials under development for use as a cathodes in lithium-ion batteries olivine-type LiFePO4 is one of the most promising cathode material. However, its poor conductivity and low lithium-ion diffusion limits its practical application. In this study, we report seven different carboxylic acids used to synthesize LiFePO4/C composite, and influences of carbon sources on electrochemical performance were intensively studied. The structure and electrochemical properties of the LiFePO4/C were characterized by X-ray diffraction, scanning electron microscopy, electrical conductivity, and galvanostatic charge-discharge measurements. Among the materials studied, the sample E with tartaric acid as carbon source exhibited the best cell performance with a maximum discharge capacity of 160 mAh g(-1) at a 0.1 C-rate. The improved electrochemical properties were attributed to the reduced particle size and enhanced electrical contacts by carbon.