Developing advanced electrode materials and understanding their reaction mechanisms are two crucial issues for development of high-performance sodium ion batteries (SIBs). Herein, we synthesized a bimetallic single-phase nanoporous (NP) SnSb alloy with a bicontinuous ligament-channel structure through elaborate design of ternary Mg-Sn-Sb precursor and chemical dealloying. As an anode for SIBs, the NP-SnSb alloy delivers high specific capacity, excellent cycling stability (506.6 mAh g⁻¹ after 100 cycles at 0.2 A g⁻¹; 457.9 mAh g⁻¹ after 150 cycles at 1.0 A g⁻¹) and superior rate capability (458.2 mAh g⁻¹ at 10 A g⁻¹). Moreover, the Na₃V₂(PO₄)₃ (cathode)/NP-SnSb (anode) full cell also exhibits outstanding electrochemical performance (cycling stability and rate capability). The unique nanoporous structure (with ligaments of 38.9 ± 7.3 nm), the alloying effect and the synergetic reaction of Sn/Sb account for the eminent electrochemical properties of NP-SnSb. Most importantly, the Na storage mechanism of SnSb alloy was revealed using operando X-ray diffraction and density functional theory calculations. Rather than separate reactions of Sn and Sb, the reaction of SnSb alloy proceeds through a synergetic sodiation/desodiation process via the mechanism: SnSb (crystalline) ↔ Na(Sn,Sb) (amorphous) ↔ Na₉(Sn,Sb)₄ (amorphous/low-crystalline) ↔ Na₁₅(Sn,Sb)₄ (crystalline).

开发高级电极材料并了解其反应机理是开发高性能钠离子电池（SIB）的两个关键问题。在此，我们通过精心设计三元Mg-Sn-Sb前驱体并进行化学脱合金，合成了具有双连续韧带通道结构的双金属单相纳米多孔（SnSb）SnSb合金。作为SIB的阳极时，NP-SnSb系合金提供高的比容量，优异的循环稳定性（506.6毫安克^-1，在100次循环后0.2 A克^-1 ; 457.9毫安克^-1在1.0克150次循环后^-1）和优异的倍率性能（458.2毫安克^-1以10 A G ^-1）。此外，Na ₃ V ₂（PO ₄）₃（阴极）/ NP-SnSb（阳极）全电池也表现出出色的电化学性能（循环稳定性和速率能力）。独特的纳米孔结构（38.9±7.3 nm韧带），Sn / Sb的合金化作用和协同反应说明了NP-SnSb的卓越电化学性能。最重要的是，使用操作X射线衍射和密度泛函理论计算揭示了SnSb合金的Na储存机理。SnSb合金不是通过Sn和Sb的单独反应，而是通过以下机制通过协同的增盐/脱碱过程进行反应：SnSb（晶体）↔Na（Sn，Sb）（非晶）↔Na ₉（Sn，Sb）₄（非晶/低结晶））Na ₁₅（Sn，Sb）₄（结晶）。