Sodium‐ion batteries (SIBs) have attracted significant research interest for large‐scale electric energy storage. However, anodes with good rate capability and long cycle life are still lacking. Here, a three‐dimensional (3D) porous Sn on Cu foil (Sn/Cu) is prepared by tuning the redox potential of Cu⁺/Cu with a ligand of thiourea to trigger the replacement reaction between Cu and Sn²⁺. The as‐synthesized Sn/Cu is used as an integrated porous electrode and can be directly applied as an advanced freestanding electrode for SIBs. Such a unique structure can efficiently relieve the strain caused by sodiation/desodiation and benefit penetration of the electrolyte and diffusion of Na⁺. This is a merit of its large reversible capacity of about 700 mAh g⁻¹ at 2500 mA g⁻¹ for 400 cycles. A full battery of Sn/Cu//Na₃(VO_0.5)₂(PO₄)₃F₂ is constructed, which presents a high energy density of 311.7 Wh kg⁻¹ and long lifespan of 200 cycles. This facile synthesis strategy and good electrochemical performance will encourage more investigations into structure design of functional materials.

中文翻译：

---

通过调节氧化还原电位产生的3D多孔锡充当钠离子电池的高级电极

钠离子电池（SIB）在大规模电能存储方面引起了广泛的研究兴趣。然而，仍然缺乏具有良好的速率能力和长循环寿命的阳极。在此，通过用硫脲的配体调节Cu ⁺ / Cu的氧化还原电位以触​​发Cu和Sn ²⁺之间的置换反应来制备三维（3D）Cu箔上的多孔Sn（Sn / Cu）。合成后的Sn / Cu用作集成多孔电极，可直接用作SIB的高级独立式电极。这种独特的结构可以有效地缓解由氧化/脱盐引起的应变，并有利于电解质的渗透和Na ^+的扩散。这是其约700 mAh g的大可逆容量的优点^-1在2500 mA g ^-1下进行400个循环。构造了完整的Sn / Cu // Na ₃（VO _0.5）₂（PO ₄）₃ F ₂电池，该电池具有311.7 Wh kg ^-1的高能量密度和200个循环的长寿命。这种简便的合成策略和良好的电化学性能将鼓励对功能材料的结构设计进行更多的研究。