Hydrogen-Bonding Guar Gum Stabilizes Solid-State Si Anodes

Abstract

Solid-state silicon (Si) anodes are promising for all-solid-state Li batteries but their large cycling-induced volume fluctuations cause severe structural instability. In this work, guar gum (GG), a binder commonly used in liquid-electrolyte Si anodes yet rarely applied in solid-state systems, is introduced as an alternative to PVDF. The GG-based solid-state Si anode shows increased capacity, initial Coulombic efficiency, rate capability and cycling stability, with the initial discharge capacity and initial CE reaching 3349 mAh/g and 90.4%, respectively. GG enhances mechanical integrity through abundant hydrogen bonding, effectively suppressing stress accumulation associated with Si volume changes and thereby improving electrochemical performance.