Carbon-Confined Sno2-Electrodeposited Porous Carbon Nanofiber Composite as High-Capacity Sodium-Ion Battery Anode Material
Carbon-Confined Sno2-Electrodeposited Porous Carbon Nanofiber Composite as High-Capacity Sodium-Ion Battery Anode Material
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DOI：
10.1021/acsami.5b04338
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发表时间：
2015-08-26
影响因子：
9.5
通讯作者：
Zhang, Xiangwu
中科院分区：
文献类型：
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作者：
Dirican, Mahmut;Lu, Yao;Zhang, Xiangwu
钠资源既便宜又丰富，因此钠离子电池是锂离子电池的理想替代品。然而，目前的钠离子电池能量密度低，循环稳定性差，阻碍了其在未来智能电网和固定存储应用中的实际实施。锡氧化物（SnO2）具有高钠存储容量、高丰度、低毒性等优点，有望作为未来钠离子电池的高容量负极材料。然而，基于sno2的阳极仍然不能用于实际的钠电池，因为它们在重复的充放电循环中会经历很大的体积变化。如此大的体积变化导致活性物质严重粉碎，SnO2和碳导体之间失去电接触，从而导致循环过程中容量的快速损失。在这里，我们介绍了一种新的无定形碳涂层SnO2多孔碳纳米纤维（PCNF@SnO2@C）复合材料，该复合材料不仅具有高钠存储能力，而且在进行重复循环时保持其结构完整性。电化学结果表明，该含sno2纳米纤维复合阳极具有高容量（374 mAh g(-1)）、良好的容量保持率（82.7%）和高库仑效率（98.9%）等优异的电化学性能。
Sodium resources are inexpensive and abundant, and hence, sodium ion batteries are promising alternative to lithium-ion batteries. However, lower energy density and poor cycling stability of current sodium-ion batteries prevent their practical implementation for future smart power grid and stationary storage applications. Tin oxides (SnO2) can be potentially used as a high-capacity anode material for future sodium-ion batteries, and they have the advantages of high sodium storage capacity, high abundance, and low toxicity. However, SnO2-based anodes still cannot be used in practical sodiumion batteries because they experience large volume changes during repetitive charge and discharge cycles. Such large volume changes lead to severe pulverization of the active material and loss of electrical contact between the SnO2 and carbon conductor, which in turn result in rapid capacity loss during cycling. Here, we introduce a new amorphous carbon-coated SnO2 porous carbon nanofiber (PCNF@SnO2@C) composite that not only has high sodium storage capability, but also maintains its structural integrity while ongoing repetitive cycles. Electrochemical results revealed that this SnO2-containing nanofiber composite anode had excellent electrochemical performance including high-capacity (374 mAh g(-1)), good capacity retention (82.7%), and large Coulombic efficiency (98.9% after 100th cycle).