Carbon-coated LiFePO4–porous carbon composites as cathode materials for lithium ion batteries

Abstract

This work introduces a facile strategy for the synthesis of carbon-coated LiFePO₄–porous carbon (C-LiFePO₄–PC) composites as a cathode material for lithium ion batteries. The LiFePO₄ particles obtained are about 200 nm in size and homogeneously dispersed in porous carbon matrix. These particles are further coated with the carbon layers pyrolyzed from sucrose. The C-LiFePO₄–PC composites display a high initial discharge capacity of 152.3 mA h g⁻¹ at 0.1 C, good cycling stability, as well as excellent rate capability (112 mA h g⁻¹ at 5 C). The likely contributing factors to the excellent electrochemical performance of the C-LiFePO₄–PC composites could be related to the combined effects of enhancement of conductivity by the porous carbon matrix and the carbon coating layers. It is believed that further carbon coating is a facile and effective way to improve the electrochemical performance of LiFePO₄–PC.