Hollow Li2FeSiO4 spheres as cathode and anode material for lithium-ion battery

Hollow Li2FeSiO4 spheres have been successfully prepared using hollow silica spheres as both reactant and template, for which the thickness of the nanoscale Li2FeSiO4 thin shells are about 50 nm. Then, the hollow Li2FeSiO4 spheres were coated by phenolic resin as a carbon precursor to obtain the hollow Li2FeSiO4/Carbon sphere (HLFS/C) composite. The structure characterizations by X-ray diffraction, transmission electron microscopy and scanning electron microscopy show that the HLFS/Cs are hollow structures with high purity. When used as the cathode material under charge/discharge rates at 0.05C (1C = 166 mAh g−1), the HLFS/C exhibited a capacity of 155 mAh g−1 with good cycle stability. Furthermore, the HLFS exhibited capacities of 820, 650 and 420 mAh g−1 for 0.15C, 0.3C and 0.6C rates for anode application, respectively, with good cycle stability. The hollow structure of HLFS/C enables us to overcome the aggregation and structural instability problems, which is essential for the improvement of the electrochemical performance.