Boosted electrochemical properties of porous Li2FeSiO4/C based on Fe-MOFs precursor for lithium ion batteries

Li2FeSiO4/C cathode composites were fabricated from a simple solid-state approach using precursor Fe-MOFs prepared by hydrothermal process. The Li2FeSiO4/C composites covered by carbon film with diverse contents were characterized using XRD, SEM, galvanostatic charge-discharge measurement and EIS, and so on. Results of the investigation prove that Li2FeSiO4/C composites with 19.3 wt % carbon layer present prominent electrochemical capability, which delivered the discharge capacity of 154, 138, 129, 117 and 100 mA h g(-1) at 0.2, 0.5, 1, 2 and 5 C, respectively. After 100 cycles, discharge capacity retained 97.4% compared to the original value at 2 C. Furthermore, it possesses the lowest charge transfer resistance as well as the highest Li+ diffusion coefficient, attributing to uniform carbon coating and porous structure for Li2FeSiO4/C composites.