Abstract Sn anode materials with high specific capacity are an appealing alternative to graphite for next-generation advanced lithium-ion batteries. However, poor electrochemical performance originating from fracture and pulverization due to the enormous volume changes during lithium alloying/dealloying hinders their commercial applications. Here, we propose the synthesis of a novel 3D structured Sn anode material by a facile method: heat treatment of nanosized SnO2 spheres in a tube furnace with a flowing mixed atmosphere of C2H2/Ar at 400 °C. After the heat treatment, the nanosized SnO2 spheres convert into pure Sn bulk material (~20 μm), which consists of Sn nanowires (~50 nm in diameter and several microns in length). This unique 3D structure with sufficient voids between the nanowires effectively mitigates the volume expansion of Sn bulk material and ensures good electrical contact between the anode material and conducting additives. As a consequence, the 3D structured Sn anode material exhibits a specific reversible capacity of ~600 mA h/g and no significant capacity degradation (compared with that of the 20th cycle) over 500 cycles at 0.2 C.

中文翻译：

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一种合成具有优异电化学性能的锂离子电池3D结构Sn负极材料的简便方法

摘要 具有高比容量的 Sn 负极材料是下一代先进锂离子电池石墨的有吸引力的替代品。然而，由于锂合金化/脱合金过程中巨大的体积变化导致断裂和粉化导致电化学性能不佳，阻碍了它们的商业应用。在这里，我们建议通过一种简便的方法合成一种新型 3D 结构的 Sn 阳极材料：在管式炉中在 400°C 下在 C2H2/Ar 的流动混合气氛中热处理纳米尺寸的 SnO2 球。热处理后，纳米尺寸的 SnO2 球体转化为纯 Sn 块状材料（~20 μm），由 Sn 纳米线（直径约 50 nm，长度几微米）组成。这种独特的 3D 结构在纳米线之间具有足够的空隙，有效地减轻了 Sn 块状材料的体积膨胀，并确保了阳极材料和导电添加剂之间的良好电接触。因此，3D 结构的 Sn 负极材料表现出~600 mA h/g 的比可逆容量，并且在 0.2 C 下超过 500 次循环后没有显着的容量下降（与第 20 次循环相比）。