Nonstoichiometric LiF modified F-LiFePO4/C cathode material is successfully synthesized by solid-state-reaction using LiF as the additive and FePO4 and Li2CO3 as precursors. The synthesized F-LiFePO4/C powders are characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscope (TEM), Raman spectrum, X-ray photoelectron emission microscopy (XPS) and potentiostatic intermittent titration technique (PITT). The XRD results show that the LiF additive modification can improve the crystallinity of LiFePO4 without introducing any impurities. LiF modification has little influence on LiFePO4 crystal structure based on lattice parameters, calculated by MDI Jade 6. The DSC curve shows that a LiF additive can lower the LiFePO4 formation temperature by about 100 degrees C. F1s signal and a C-F bond have been discovered on the surface of the modified sample via XPS analysis, indicating that LiF has an influence on the chemical reaction. The final particle size varied with LiF additive content based on SEM and HRTEM images. F-LiFePO4/C samples have better and clearer crystal fringes than the untreated LiFePO4/C sample from HRTEM, which suggests that LiF modification can improve the crystallinity of LiFePO4. Charge-discharge curves indicate that the F-LiFePO4/C sample has excellent capacities at high discharge rates: 130.0 mAh g(-1) at 5 degrees C. PITT indicates that the F-LiFePO4/C sample has a higher Li+ ion diffusion coefficient than the LiFePO4/C sample. (C) 2014 Elsevier B.V. All rights reserved.