Bismuth - antimony bimetallic sulfide anode for wide - temperature sodium storage enabled by rational structure and electrolyte modulation.

Alloy-conversion anodes are promising candidates for high-capacity sodium storage, yet their practical application is hindered by sluggish reaction kinetics, severe volume fluctuation, and unstable interfacial chemistry. Herein, a bimetallic BiSb sulfide with carbon confined (BiSbS3@C) nanorod is rationally constructed to regulate both bulk structural evolution and interfacial charge transport. The integrated carbon framework provides continuous electronic pathways and mechanical confinement, while the dual-metal synergy tailors volume strains and facilitates reversible conversion-alloying processes. In parallel, electrolyte engineering is introduced to further optimize interphase chemistry, where the mixed-ether electrolyte NaPF6-DME/Diglyme promotes the formation of a compact and inorganic-rich interphase, enabling faster Na+ migration and lower polarization. The cooperative regulation of electrode/electrolyte design effectively mitigates interfacial polarization and structural degradation. Consequently, the BiSbS3@C electrode paired with NaPF6-DME/Diglyme electrolyte delivers the optimal reaction kinetics, outstanding rate capability, and prolonged cycling stability. Impressively, the composite maintains stable operation in half-/full-cells at low- and high-temperature (-20 °C to 50 °C), highlighting the system with wide-temperature adaptability. This work provides a viable strategy for constructing alloy-conversion anodes through coupled material/electrolyte engineering, offering practical guidance for harsh climate energy storage.