Carbon-coated SnO2 thin films developed by magnetron sputtering as anode material for lithium-ion batteries

The magnetron sputtering technique was employed to produce carbon-coated SnO2 (CCSO) thin films, which were applied as an anode material for lithium-ion batteries (LIBs). The CCSO shows better electrochemical properties than the pure SnO2 material. The CCSO thin film has a specific discharge capacity of 650 mA h g(-1) with a capacity retention rate of 72% after 100 cycles, while the pure SnO2 has only 207 mA h g(-1) with a capacity retention rate of 19%. High-resolution transmission electron microscopic analysis provides crucial information that the magnetron-sputtered carbon coating has an amorphous feature and shows excellent durability because the carbon film is coated tightly on the surface of the SnO2 active materials through the discharging and charging cycles. The amorphous carbon coating on the surface of SnO2 thin film reduced the electrode deterioration, and effectively improved the conductivity and electrochemical stability of the electrode in LIBs.