Three-Dimensional Cu2ZnSnS4 Films with Modified Surface for Thin-Film Lithium-Ion Batteries

Cu2ZnSnS4 (CZTS) is an important material in low-cost thin film solar cells and is also a promising candidate for lithium storage. In this work, a novel three-dimensional CZTS film coated with a lithium phosphorus oxynitride (LiPON) film is fabricated for the first time and is applied to thin-film lithium-ion batteries. The modified film exhibits an excellent performance of ∼900 mAh g(-1) (450 μAh cm(-2) μm(-1)), even after 75 cycles. Morphology integrity is still maintained after repeated lithiation/delithiation, and the main reaction mechanism is analyzed in detail. The significant findings from this study indicate the striking advantages of modifying both the surface and structure of alloy-based electrodes for energy storage.