Fluorine doped carbon coating of LiFePO4 as a cathode material for lithium-ion batteries.

• The concept of fluorine doped carbon is proposed; • Polyvinylidene fluoride is used as carbon and fluoride source; • The optimal LFP@F-doped carbon nanocomposites delivered a practical capacity and cyclability. The present work presents an insightful study on the effect of fluorine doped carbon (FC) modification on the electrochemical performance of LiFePO 4 cathode material. To this end, polyvinylidene fluoride is used as fluoride source to synthesize FC, which is designed to coat on LiFePO 4 surface with formation of LiFePO 4 @FC nanocomposites. The microstructure and electrochemical properties of the nanocomposites are systematically examined by various characterization techniques, revealing that FC is tightly attached on surface of LiFePO 4 particles forming a three dimensional (3D) conductive network structure. Such favorable structure provides advantages of good grain-to-grain electrical contact, shortening the Li+ diffusion distance between the grain interfaces, and facilitating the rapid transfer of electrons during charge–discharge. The optimal LiFePO 4 @FC nanocomposites, i.e. , with 97.2 wt% of LiFePO 4 , are verified to show highly desirable electrochemical performance with superior rate capability and excellent cycling performance as the cathode material of lithium-ion batteries. [ABSTRACT FROM AUTHOR]