Effect of carbon coating on the electrochemical properties of Co2SnO4 for negative electrodes in Li-ion batteries

Co2SnO4 particles were synthesized by a sonochemical method under different pH conditions, followed by carbon coating by a hydrothermal method. The thermal stability and compound formation temperature were identified through thermogravimetric analysis (TGA). The X-ray diffraction (XRD) pattern elucidated the compound formation of Co2SnO4 with cubic structure. Co2SnO4 encapsulated with carbon was confirmed through the TEM and HRTEM analysis and the approximate thickness of carbon was around 20 nm. The pristine-Co2SnO4 and carbon coated Co2SnO4 provided a discharge capacity of 777 mA h g−1 and 780 mA h g−1 at the current density of 40 mA g−1 with the capacity retention of 67% and 81% respectively in the 20th cycle. The charge transfer resistance of carbon coated Co2SnO4 was low when compared to pristine Co2SnO4 which lead to good reversibility of the material. The electrochemical study revealed the excellent electrochemical performance of the carbon coated Co2SnO4 particles with superior cycling stability and electronic conductivity.