A nanosized SnSb alloy confined in N-doped 3D porous carbon coupled with ether-based electrolytes toward high-performance potassium-ion batteries
A nanosized SnSb alloy confined in N-doped 3D porous carbon coupled with ether-based electrolytes toward high-performance potassium-ion batteries
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限制在氮掺杂 3D 多孔碳中的纳米 SnSb 合金与醚基电解质相结合，用于高性能钾离子电池
DOI：
10.1039/c9ta03851e
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发表时间：
2019
影响因子：
11.9
通讯作者：
Zhao Naiqin
中科院分区：
文献类型：
--
作者：
Wang Zhiyuan;Dong Kangze;Wang Dan;Luo Shaohua;Liu Yanguo;Wang Qing;Zhang Yahui;Hao Aimin;Shi Chunsheng;Zhao Naiqin
钾离子电池（PIB）被认为是一种有前途的新一代储能装置，因为它们可以用作锂离子电池的替代或补充。然而，K+的大半径和缓慢的扩散动力学使得开发高性能PIB电极材料面临巨大挑战。在此，通过使用氯化钠模板辅助原位热解策略制备了一种限制在氮掺杂三维多孔碳中的新型锡锑合金纳米复合材料（3D SnSb@NC），并研究了作为基于二甲氧基乙烷（DME）和传统酯基（EC/DEC）电解质的PIB的阳极。由于Sn和Sb的协同作用，均匀锚定的SnSb纳米颗粒可以有效缓解钾化/去钾过程中剧烈的体积变化。 N掺杂的3D多孔碳可以防止SnSb纳米颗粒的聚集，为K+提供丰富的活性位点，促进电解质的充分渗透，并作为导电网络加速电子传输。此外，基于DME的电解质对3D SnSb@NC电极表现出优异的润湿性，并形成更薄的SEI膜，从而导致可忽略不计的表面膜阻抗和降低的电荷转移阻抗。因此，合理的3D SnSb@NC结构与优化的DME基电解质相结合，使PIB在50 mA g−1下具有357.2 mA h g−1的高可逆容量、高达90.1%的初始库仑效率（ICE）、良好的倍率性能和出色的循环稳定性，在0.5 A g−1下200次循环后容量保持率为80%。这项工作提出了一种先进的概念，用于设计具有兼容电解质的高性能 PIB 的多功能阳极材料。
Potassium-ion batteries (PIBs) have been considered as a promising new-generation energy storage device because they can be used as a replacement or complement to lithium-ion batteries. However, the large radius and the sluggish diffusion kinetics of K+ make it a great challenge to develop high-performance electrode materials for PIBs. Herein, a novel nanocomposite of SnSb alloy confined in N-doped three-dimensional porous carbon (3D SnSb@NC) is fabricated by using the NaCl template-assisted in situ pyrolysis strategy and investigated as an anode for PIBs based on dimethoxyethane (DME)-based and conventional ester-based (EC/DEC) electrolytes. The uniformly anchored SnSb nanoparticles could effectively alleviate dramatic volume variation during potassiation/depotassiation owing to the synergistic effect of Sn and Sb. N-doped 3D porous carbon prevents the aggregation of SnSb nanoparticles, provides abundant active sites for K+, facilitates sufficient infiltration of the electrolyte, and serves as a conductive network to accelerate the electron transport. Moreover, the DME-based electrolyte shows superior wettability to the 3D SnSb@NC electrode and forms a thinner SEI film, resulting in negligible surface film impedance and reduced charge transfer impedance. Consequently, the rational 3D SnSb@NC structure coupled with an optimized DME-based electrolyte makes PIBs deliver a high reversible capacity of 357.2 mA h g−1 at 50 mA g−1, an remarkable initial coulombic efficiency (ICE) of 90.1%, good rate capability, and excellent cycling stability with a capacity retention of 80% after 200 cycles at 0.5 A g−1. This work presents an advanced concept for designing multifunctional anode materials with compatible electrolytes for high-performance PIBs.