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

Abstract

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.