Kong Ming, Liu Yan, Zhou Bin, Yang Kaixuan, Tang Jianfeng, Zhang Ping, Zhang Wen-Hua
College of Materials Science and Engineering, Sichuan University, Chengdu, 610064, China.
Sichuan Research Center of New Materials, Institute of Chemical Materials, China Academy of Engineering Physics, Chengdu, 610200, China.
Small. 2020 Oct;16(43):e2001976. doi: 10.1002/smll.202001976. Epub 2020 Sep 28.
Antimony is an attractive anode material for sodium-ion batteries (SIBs) owing to its high theoretical capacity and appropriate sodiation potential. However, its practical application is severely impeded by its poor cycling stability caused by dramatic volumetric variations during sodium uptake and release processes. Here, to circumvent this obstacle, Sb@C@TiO triple-shell nanoboxes (TSNBs) are synthesized through a template-engaged galvanic replacement approach. The TSNB structure consists of an inner Sb hollow nanobox protected by a conductive carbon middle shell and a TiO -nanosheet-constructed outer shell. This structure offers dual protection to the inner Sb and enough room to accommodate volume expansion, thus promoting the structural integrity of the electrode and the formation of a stable solid-electrolyte interface film. Benefiting from the rational structural design and synergistic effects of Sb, carbon, and TiO , the Sb@C@TiO electrode exhibits superior rate performance (212 mAh g at 10 A g ) and outstanding long-term cycling stability (193 mAh g at 1 A g after 4000 cycles). Moreover, a full cell assembled with a configuration of Sb@C@TiO //Na (VOPO ) F displays a high output voltage of 2.8 V and a high energy density of 179 Wh kg , revealing the great promise of Sb@C@TiO TSNBs as the electrode in SIBs.
由于具有较高的理论容量和合适的钠化电位，锑是一种有吸引力的钠离子电池（SIBs）阳极材料。然而，在钠的嵌入和脱出过程中，由于其体积的剧烈变化导致循环稳定性差，严重阻碍了其实际应用。在此，为了克服这一障碍，通过模板参与的电化学生成置换法合成了Sb@C@TiO三壳层纳米盒（TSNBs）。TSNB结构由一个内部的Sb空心纳米盒组成，该纳米盒由导电的碳中间壳层和TiO纳米片构成的外壳层保护。这种结构为内部的Sb提供了双重保护，并提供了足够的空间来容纳体积膨胀，从而促进了电极的结构完整性和稳定的固体电解质界面膜的形成。得益于合理的结构设计以及Sb、碳和TiO的协同效应，Sb@C@TiO电极展现出优异的倍率性能（在10 A g时为212 mAh g）和出色的长期循环稳定性（在1 A g下循环4000次后为193 mAh g）。此外，采用Sb@C@TiO//Na（VOPO）F配置组装的全电池显示出2.8 V的高输出电压和179 Wh kg的高能量密度，这表明Sb@C@TiO TSNBs作为SIBs电极具有巨大的潜力。
