Graphene modified Li2FeSiO4/C composite as a high performance cathode material for lithium-ion batteries

Graphene modified Li2FeSiO4/C composite (Li2FeSiO4/C/G) has been synthesized successfully by a chemical vapor deposition (CVD)-assisted two-step solid-state reactions. The Li2FeSiO4/C/G composite is characteristic of Li2FeSiO4 nanoparticles with a diameter of about 10–30 nm which are homogeneously dispersed on the graphene sheet substrate and coated by a thin layer of carbon. Galvanostatic charge–discharge test showed that Li2FeSiO4/C/G composite delivers a reversible capacity of 153.0 mA g−1 at 0.2 C rate, corresponding to 92 % of the theoretical capacity. Furthermore, cycling behavior and rate capability of the Li2FeSiO4/C/G are good. Our results indicated that the 2D conducting network formed by the carbon-coated Li2FeSiO4 particles and hierarchically graphene nanosheets enhances the electronic conductivity and stabilizes the flake structure and reduces agglomeration of the particles as well.