Sulphur-template method for facile manufacturing porous silicon electrodes with enhanced electrochemical performance

Abstract

Sulphur (S)-template method based on conventional slurry-casting method has been developed to produce porous silicon (Si) electrodes. The facile fabrication technology is suitable for current production line and expected to be widely applied to various electrode materials under large volume change during operation. Specifically, S particles as template agent are mixed with active material Si, carbon conductor and binder forming uniform slurry. After casting and drying, the electrodes are immersed in carbon disulfide solution to remove S particles rapidly, generating pores in-situ at the original position of S particles. Electrochemical analysis shows that the pores inside electrodes are able to shorten lithium ion diffusion paths, reduce normal expansion rate and decrease formation of cracks in the Si electrode (2 mgSi/cm2), demonstrating a reversible capacity of 951 mAh/g at 0.5 A/g after 100 cycles (with a capacity retention of 99.5%) and a capacity of ∼826 mAh/g at 2 A/g.