Surfactant-Assisted Synthesis of Micro/Nano-Structured LiFePO4 Electrode Materials with Improved Electrochemical Performance.

Abstract

As an electrode material, LiFePO4 has been extensively studied in the field of energy conversion and storage due to its inexpensive cost and excellent safety, as well as good cycling stability. However, it remains a challenge to obtain LiFePO4 electrode materials with acceptable discharge capacity at low temperature. Here, micro/nano-structured LiFePO4 electrode materials with grape-like morphology were fabricated via a facile solvothermal approach using ethanol and OA as the co-solvent, the surfactant as well as the carbon source. The structure and electrochemical properties of the LiFePO4 material were investigated with x-ray diffraction (XRD), field emission scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the formation mechanism of the self-assembled micro/nano-structured LiFePO4 was discussed as well. The micro/nano-structured LiFePO4 electrode materials exhibited a high discharge capacity (142 mAh·g-1) at a low temperature of 0 °C, and retained 102 mAh·g-1 when the temperature was decreased to -20 °C. This investigation can provide a reference for the design of micro/nano-structured electrode materials with improvement of the electrochemical performance at low temperature.