Synthesis of carbon nanotubes-supported porous silicon microparticles in low-temperature molten salt for high-performance Li-ion battery anodes

Silicon-based materials has attracted attention as a promising candidate for lithium-ion batteries (LIBs) with high energy density. However, severe volume variation, pulverization, and poor conductivity hindered the development of Si based materials. In this study, porous Si microparticles supported by carbon nanotubes (p-Si/CNT) are fabricated through simple molten salt assisted dealloying process at low temperature followed by acid treatment. The ZnCl2 molten salt not only provides the liquid environment to enhance the reaction, but also participates the dealloying process and works as template for porous structure when removes by acid treatment. Additionally, distribution of defect sites in CNTs also increases after molten salt process. Density function theory (DFT) calculations further prove the defects could improve the adsorption of Li+. The participation of CNTs can also contribute to the reaction kinetics and retain the integrity of the electrode. As expected, the p-Si/CNT anode manifests enhanced lithium-storage performance in terms of superior cycling stability and good rate capability. The p-Si/CNT//LiCoO2 full cell assembly further demonstrates its potential as a prospective anode for high-performance LIBs.