A facile hydrothermal method to prepare LiFePO4/C submicron rod with core–shell structure

Abstract

Submicron rod LiFePO4/C has been synthesized via a facile hydrothermal process. The morphology, crystal structure, and charge–discharge performance of the prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and galvanostatic charge–discharge testing. The SEM and TEM illustrate that submicron rods with a width of about 140 nm and a length of up to 400 nm have been obtained. The TEM test also indicates a “core–shell” structure with a 1.5–2 nm carbon shell on the LiFePO4 core. Even though the separate carbon-coated procedure is not used in this method, the electrochemical behavior results are satisfied. It displays that LiFePO4/C has highly crystalline and a desirable core–shell structure with uniform carbon film. Galvanostatic battery testing shows that LiFePO4/C delivers 104 mAh g−1 at 5 C rates. The highest specific capacity of 166 mAh g−1 is achieved at 0.1 C rate, and 99.8 % of the initial specific capacitance remained after 30 cycles.