Chloride-Ion-Enriched\nSolid Electrolyte Interphase\nwith Rapid Na<sup>+</sup> Migration toward High-Performance Sodium-Ion\nBatteries

Sodium-ion batteries (SIBs) have emerged as potential\nalternatives\nto lithium-ion batteries (LIBs), particularly for large-scale applications.\nAlloy-type anode materials for sodium-ion batteries are esteemed as\nprospective candidate materials for sodium-ion anodes, owing to their\nelevated theoretical capacity, heightened utilization efficiency,\nand minimal production of insulating byproducts. However, the severe\nvolume changes and sluggish ion diffusion kinetics can lead to irreversible\nparticle fragmentation and reaggregation phenomena, ultimately resulting\nin electrode degradation. Additionally, repetitive volume changes\ncan cause an unstable solid electrolyte interphase (SEI). This study\npresents the synthesis of chloride-ion-modulated bimetallic SnSb/C\nnanoparticle anode materials, highlighting the following advantages:\n(i) Designing a bimetallic SnSb alloy structure serves to buffer the\nstructural stresses generated during sodium insertion/extraction processes,\neffectively mitigating particle fracture phenomena induced by electrode\nmaterial expansion/contraction. (ii) Nanostructuring both alloy materials\nenables the full utilization of active materials and shortens diffusion\npathways, thereby significantly enhancing the diffusion rate of sodium\nions. (iii) Introducing a carbonaceous matrix serves to alleviate\nself-agglomeration phenomena of the material during charge/discharge\ncycles, enhancing the material’s conductivity and structural\nstability. (iv) Utilizing chloride-ion interface modification to achieve\na chloride-rich solid-electrolyte interphase (SEI) enhances battery\nperformance.