Two-Dimensional Tin Disulfide Nanosheets for Enhanced Sodium Storage
Two-Dimensional Tin Disulfide Nanosheets for Enhanced Sodium Storage
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DOI：
10.1021/acsnano.5b05229
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发表时间：
2015-11-01
期刊：
影响因子：
17.1
通讯作者：
Yan, Qingyu
中科院分区：
文献类型：
--
作者：
Sun, Wenping;Rui, Xianhong;Yan, Qingyu
由于钠的丰富，钠离子电池被认为是锂离子电池在电网储能方面的补充。然而，现有阳极的容量低、倍率能力差、循环稳定性差等问题严重阻碍了SIB的实际应用。本文通过简单的回流法制备了厚度为3-4 nm的超薄二维SnS_2纳米片，以增强钠的储存。SnS_2纳米片具有较高的Na~+表观扩散系数和快速的钠/脱盐反应动力学。在半电池中，纳米片在0.1Ag(-1)时的可逆容量为733mAhg(-1)，在2Ag(-1)时仍保持高达435mAhg(-1)的可逆容量。在50次循环中，0.1Ag(-1)的容量保持率高达647 mAh g(-1)，这是目前为止SnS2的最好性能，表明纳米片状结构除了有利于提高倍率性能外，还有利于提高循环稳定性。SnS2纳米片在Na3V2(PO4)(3)阴极的全电池中也显示出令人鼓舞的性能。此外，还利用非原位X射线衍射仪和高分辨透射电子显微镜研究了钠的储存机理。高的比容量、良好的倍率性能和循环耐久性表明SnS2纳米片作为高性能SIB的阳极具有很大的潜力。
Sodium-ion batteries (SIBs) are considered as complementary alternatives to lithium-ion batteries for grid energy storage due to the abundance of sodium. However, low capacity, poor rate capability, and cycling stability of existing anodes significantly hinder the practical applications of SIBs. Herein, ultrathin two-dimensional SnS2 nanosheets (3-4 nm in thickness) are synthesized via a facile refluxing process toward enhanced sodium storage. The SnS2 nanosheets exhibit a high apparent diffusion coefficient of Na+ and fast sodiation/desodiation reaction kinetics. In half-cells, the nanosheets deliver a high reversible capacity of 733 mAh g(-1) at 0.1 A g(-1), which still remains up to 435 mAh g(-1) at 2 A g(-1). The cell has a high capacity retention of 647 mA h g(-1) during the 50th cycle at 0.1 A g(-1), which is by far the best for SnS2, suggesting that nanosheet morphology is beneficial to improve cycling stability in addition to rate capability. The SnS2 nanosheets also show encouraging performance in a full cell with a Na3V2(PO4)(3) cathode. In addition, the sodium storage mechanism is investigated by ex situ XRD coupled with high-resolution TEM. The high specific capacity, good rate capability, and cycling durability suggest that SnS2 nanosheets have great potential working as anodes for high-performance SIBs.