Synthesis and characterization of nano-Li1.95FeSiO4/C composite as cathode material for lithium-ion batteries

Li1.95FeSiO4/C and Li2FeSiO4/C composites were synthesized by a traditional solid-state reaction method and then discussed comparatively through the results of X-ray diffraction (XRD), scanning electron microscopy (SEM), the Brunauer–Emmet–Teller (BET) method, the charge–discharge test and electrochemical impedance spectra measurement, respectively. The results demonstrated that the Li1.95FeSiO4/C composite could exhibit much better battery performance in terms of the discharge capacity, cycling stability and rate capability in comparison with the Li2FeSiO4/C composite. At 0.2C and 5C, it delivered a discharge capacity of 142 mAh g−1 and 93 mAh g−1, respectively, and after 100 cycles at 1C, 95.1% of its initial capacity was retained.