Enhancement of thin film tin oxide negative electrodes for lithium batteries

Abstract Thin films of pure SnO 2 , of the Sn/Li 2 O layered structure, and of Sn/Li 2 O were fabricated by sputtering method, while a `lithium-reacted tin oxide thin film' was assembled by the evaporation of lithium metal onto a SnO 2 thin film. Film structure and charge/discharge characteristics were compared. The lithium-reacted tin oxide thin film, the Sn/Li 2 O layered structure, and the Sn/Li 2 O co-sputtered thin films did not show any irreversible side reactions of forming Li 2 O and metallic Sn near 0.8 V vs Li/Li + . The initial charge retention of the Sn/Li 2 O layered structure and Sn/Li 2 O co-sputtered thin films was about 50% and a similar value was found for the lithium-reacted tin oxide thin film (more than 60%). Sn/Li 2 O layered structure and Sn/Li 2 O co-sputtered thin films showed better cycling behavior over 500 cycles than the pure SnO 2 and lithium-reacted tin oxide thin film in the cut-off range from 1.2 to 0 V vs Li/Li + .