The sodium-ion battery (SIB) as a promising candidate for large-scale energy storage has attracted widespread attention in recent years. However, its practical application is plagued by the lack of suitable anode materials that can afford long cycle life, high rate capability and large capacity. Herein, we report a high-performance self-supported Bi microforest (MF) anode with Bi microtree arrays uniformly grown on porous Cu foil for SIBs. The Bi MF can be directly employed as an anode without using any binders and conductive additives. Finite-element analysis and electrochemical kinetics analyses reveal that such a tree-like microstructure facilitates fast Na⁺ diffusion and promotes effective stress dissipation. As a result, the Bi MF electrode shows exceptionally high rate capability (338.9 mA h g⁻¹ at 50 A g⁻¹ with a capacity retention of 94.2%) and excellent cycling stability (95.9% capacity retention after 1200 cycles at 1 A g⁻¹). More importantly, by pairing the Bi MF anode with a Na₃V₂(PO₄)₃ cathode, the assembled full cell achieves a long cycle life and an inspiring energy density of 132.2 W h kg⁻¹, showing the great potential of the Bi MF anode in sodium-ion full-cells.

中文翻译：

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用于高性能钠储存的自支撑铋微林的仿生设计

钠离子电池（SIB）作为大规模储能的有前景的候选者近年来引起了广泛的关注。然而，其实际应用受到缺乏合适的具有长循环寿命、高倍率性能和大容量的负极材料的困扰。在此，我们报告了一种高性能自支撑 Bi 微林 (MF) 阳极，其 Bi 微树阵列均匀生长在用于 SIB 的多孔铜箔上。 Bi MF可以直接用作阳极，无需使用任何粘合剂和导电添加剂。有限元分析和电化学动力学分析表明，这种树状微观结构有利于Na ^+的快速扩散并促进有效的应力消散。结果，Bi MF电极表现出极高的倍率性能（50 A g ^{-1下为338.9 mA hg -1}，容量保持率为94.2%）和优异的循环稳定性（1 A g ^{-1下循环1200次后容量保持率为95.9%） 1}）。更重要的是，通过将Bi MF阳极与Na ₃ V ₂ (PO ₄ ) ₃阴极配对，组装的全电池实现了长循环寿命和令人鼓舞的132.2 Wh kg ^-1能量密度，显示了该材料的巨大潜力。钠离子全电池中的 Bi MF 阳极。