Defect-free solvothermally assisted synthesis of microspherical mesoporous LiFePO4/C

Abstract

Recent studies have shown that the power capability of LiFePO4 is dramatically enhanced by reducing the size of the LiFePO4 particles to nanometer dimensions. Unfortunately, the resulting intrinsically low tap density of the nano-LiFePO4 cathode significantly reduces the volumetric energy density, which is a major hurdle for the successful commercialization of this material. Here, we report the facile synthesis of carbon-coated LiFePO4 (LiFePO4/C) with a mesoporous microspherical morphology via a solvothermal process, using ethanol as the sole solvent and in the absence of chelating agents. LiFePO4/C was highly crystalline and exhibited less than 1% anti-site defects, which is important for fast lithium conduction in LiFePO4. LiFePO4/C showed an excellent rate performance (86 mAh g(-1) at a 20 C rate), a high retention ratio of 100% (140 mAh g(-1) at a 1 C rate), and a high tap density (1.2 g cm(-3)). The material is thus suitable for use as a cathode in lithium-ion batteries and for high-power energy storage devices.