Preparation of pure hydrogenated amorphous silicon film via PECVD method as anode materials for high-performance lithium-ion batteries

Abstract

In this paper, plasma-enhanced chemical vapor deposition (PECVD) is used to prepare a nano-scale pure hydrogenated amorphous silicon thin film anode, which improves the problem of large volume effect of traditional silicon-based anode materials during the charge and discharge process of lithium-ion batteries. Among them, the thinnest 120 nm pure silicon film still has a high specific capacity of 1254.6 mAh g−1 after 200 cycles at 0.5C (1C = 4.2 A g−1), and also has an excellent performance of 848.2 mAh g−1 after a large rate of charge and discharge of 5C. To give consideration to the performance and obtain a certain mass load at the same time, 170 nm pure silicon film was selected for vacuum annealing treatment at different temperatures to release the non-uniform compression stress during the deposition of hydrogenated amorphous silicon, and a more stable film structure was constructed, which further improved the performance of silicon film. Among them, the best performance is held at 100 °C for 5 h, and the reversible specific capacity of 1172.7 mAh g−1 is still maintained at 200 cycles at 0.5C, and the reversible specific capacity of 1131.6 mAh g−1 is also available at a super high rate of 10C.