Silicon nitride coated silicon thin film on three dimensions current collector for lithium ion battery anode

Silicon nitride coated silicon (N-Si) has been synthesized by two-step DC sputtering on Cu Micro-cone arrays (CMAs) at ambient temperature. The electrochemical properties of N-Si anodes with various thickness of nitride layer are investigated. From the potential window of 1.2 V-0.05 V, high rate charge-discharge and long cycle test have been executed to investigate the electrochemical performances of various N-Si coated Si-based lithium ion batteries anode materials. Higher specific capacity can be obtained after 200 cycles. The cycling stability is enhanced via thinner nitride layer coating as silicon nitride films are converted to Li3N with covered Si thin films. These N-Si anodes can be cycled under high rates up to 10 C due to low charge transfer resistance resulted from silicon nitride films. This indicates that the combination of silicon nitride and silicon can effectively endure high current and thus enhance the cycling stability. It is expected that N-Si is a potential candidate for batteries that can work effectively under high power.