Hollow Sn–Ni nanoparticles coated with ion-conductive polyethylene oxide as anodes for lithium ion batteries with superior cycling stability
Hollow Sn–Ni nanoparticles coated with ion-conductive polyethylene oxide as anodes for lithium ion batteries with superior cycling stability
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DOI：
10.1039/c5ra02956b
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发表时间：
2015-05
期刊：
影响因子：
3.9
通讯作者：
Jin Zhu;Anni Jiang;Shi Yong-qian;Xin Fan;P. Dou;D. Ma;Xinhua Xu
中科院分区：
文献类型：
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作者：
Jin Zhu;Anni Jiang;Shi Yong-qian;Xin Fan;P. Dou;D. Ma;Xinhua Xu
设计了一种简单的策略来制造由离子导电聚环氧乙烷 (PEO) 涂层包围的中空 Sn-Ni 纳米颗粒 (NP)，以解决锡基阳极面临的结构和界面稳定性问题。在空心Sn-Ni@PEO NPs的独特结构中，延展性惰性Ni作为缓冲基质可以减轻Sn的体积变化。此外，弹性离子导电PEO涂层和中空内部之间的协同效应迫使活性Sn以锂化状态向内膨胀到中空空间中，从而有效地容纳大量的体积膨胀。特别是，PEO涂层不仅抑制了循环过程中不利的Sn聚集和粉碎，而且有助于在高表面积纳米结构电极上形成稳定的固体电解质界面（SEI）膜。得益于其结构特征，空心Sn-Ni@PEO NPs在100次循环后表现出584 mA h g−1的可逆容量，并且库仑效率高于99%，优于裸露的同类材料。通过恒电流充电/放电循环、循环伏安法、电化学阻抗谱和 SEM 测量验证了 PEO 涂层和中空结构对优异循环性能的贡献。
A facile strategy is designed for the fabrication of hollow, Sn–Ni nanoparticles (NPs) surrounded by ion-conductive, polyethylene oxide (PEO) coating to address the structural and interfacial stability concerns facing Sn-based anodes. In the unique architecture of hollow Sn–Ni@PEO NPs, the ductile inactive Ni as a buffer matrix can alleviate the volume change of Sn. Moreover, the synergistic effect between the elastic ion-conductive PEO coating and the hollow interior forces the active Sn to expand inward into the hollow space in the lithiated state, and thus effectively accommodates the substantial volume expansion. In particular, the PEO coating not only suppresses the unfavorable aggregation and pulverization of Sn during cycling, but also helps in forming a stable solid electrolyte interface (SEI) film on the high surface area nanostructured electrodes. Benefiting from the structural features, hollow Sn–Ni@PEO NPs exhibit a reversible capacity of 584 mA h g−1 after 100 cycles with excellent coulomb efficiency of higher than 99%, superior to the bare counterparts. The contribution to the excellent cycling performance by the PEO coating and the hollow structure is verified by galvanostatic charge/discharge cycling, cyclic voltammetry, electrochemical impedance spectroscopy and SEM measurements.