Achieving Ultrahigh Initial Coulombic Efficiency in SnBi/C Anode for Sodium-Ion Batteries via Interfacial Engineering and Binder Optimization

Abstract

The designed deep-eutectic Sn-Bi bimetallic carbon composite microspheres (SnBi/C) with abundant phase boundaries, effectively alleviate volume deformation during sodium (de)intercalation. Accordingly, the anode fabricated with poly(ethylene oxide) binder delivers an ultrahigh Initial Coulombic Efficiency of 95.4%, along with high reversible capacity and excellent cycling stability in both half‑cells and full‑cells.