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.