Abstract

Silicon(Si)-based anodes exhibit higher energy density than traditional graphite anodes but suffer from significant volume changes during lithiation/delithiation, destabilizing the solid electrolyte interface (SEI) and reducing cycle stability. This study explores the effect of 1,3,6-hexane trinitrile (HTCN) on mitigating Si@C electrode expansion. The inclusion of HTCN modifies the original solvation structure of Li+, and the HTCN additive undergoes preferential coordination with Li+ because its binding energy with Li+ is larger than that of ethylene carbonate (EC). This lowers the lowest unoccupied molecular orbital (LUMO) of the HTCN-containing solvation structure, promoting preferential reduction decomposition on the anode surface. This process increases inorganic Li3N formation and produces a rich carbon-organic SEI film, effectively reducing electrolyte decomposition and Si@C anode expansion from 72.98 % to 4.46 %. Adding 1 % HTCN to Si@C/Li half-cells enhances capacity retention to 72.4 % after 100 cycles at 0.2C, significantly outperforming cells without HTCN (50.9 %). This study provides a new idea for constructing high-performance SEI films to inhibit electrode expansion by adjusting the solvation structure of Li+.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.