Construction of a LiF-Rich and Stable SEI Film by Designing a Binary, Ion-, and Electron-Conducting Buffer Interface on the Si Surface

Stabilizing a solid electrolyte interface (SEI) film on the Si surface is a prerequisite for realizing silicon (Si) anode applications. Interfacial engineering is one of the effective strategies to construct stable SEI films on Si surfaces and improve the electrochemical performance of the Si anodes. This work develops a silver (Ag)-decorated mucic acid (MA) buffer interface on the Si surface and the obtained Si@MA*Ag anode retains 1567 mAh g(-1) after 500 cycles at 2.1 A g(-1) and exhibits 1740 mAh g(-1) at 126 A g(-1), which are significantly higher than those of the bare Si anode of 247 and 145 mAh g(-1) under the same conditions, respectively. Analysis indicates that the improved electrochemical performance is because of the depressed volume effect of the Si particles and the sustained integrity of the electrode laminate during cycling, the enhanced lithium diffusion on the Si surface, and the improved electronic conductivity of the Si anode, as well as the facilitated formation of inorganic components in the SEI film.

Automated summary

This study develops a silver-decorated mucic acid buffer interface on the silicon surface, improving the electrochemical performance of silicon anodes by enhancing their capacity and rate capability during cycling. The improved performance is mainly attributed to the reduced volume effect of silicon particles, sustained integrity of the electrode laminate, enhanced lithium diffusion on the silicon surface, improved electronic conductivity of the silicon anode, and facilitated formation of inorganic components in the solid electrolyte interface film.