Ultrathin hybrid nanobelts of single-crystalline VO2 and Poly (3,4-ethylenedioxythiophene) as cathode materials for aqueous zinc ion batteries with large capacity and high-rate capability
Ultrathin hybrid nanobelts of single-crystalline VO2 and Poly (3,4-ethylenedioxythiophene) as cathode materials for aqueous zinc ion batteries with large capacity and high-rate capability
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单晶VO2和聚(3,4-乙撑二氧噻吩)超薄杂化纳米带作为大容量、高倍率水系锌离子电池正极材料
DOI：
10.1016/j.jpowsour.2020.228223
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发表时间：
2020-07-01
影响因子：
9.2
通讯作者：
Chu, Paul K.
中科院分区：
文献类型：
--
作者：
Liu, Xiong;Xu, Guobao;Chu, Paul K.
设计和制备大容量、高倍率性能的水溶液锌离子电池正极材料具有挑战性。本文中，合成包含单晶VO 2和聚（3，4-亚乙基二氧噻吩）（PEDOT）（命名为VO 2-PEDOT）的杂化纳米带作为AZIB的阴极材料。纳米带具有低于10 nm的厚度、大量暴露的VO 2（001）面和离散的PEDOT导电层。系统的结构和电化学评估表明，由于VO 2-PEDOT纳米带的独特结构所带来的协同效应，在Zn（CF 3SO 3）（2）电解质中，质子和Zn 2+同时插入VO 2主体中是有效的。Zn/VO 2-PEDOT电池显示出涉及两种载体的存储机制，其提供了非凡的性能，包括在0.05 Ag-1下超过0.7 V的高工作电压36.3%的540 mAhg（-1）的高容量，在10 Ag-1下231.2 mAhg（-1）的高倍率容量，优异的循环稳定性，高达1000次循环，容量保持率为84.5%。此外，50 μ m厚的独立电极组成的pH 7VO 2-PEDOT纳米带具有大的面积容量为1.35 μ Ahcm（-2）在5 Ag-1。这些结果为VO 2基阴极的电化学提供了机理上的见解，并揭示了一种提高AZIB性能的新策略，特别是在电网规模储能方面。
Design and fabrication of cathode materials with large capacity and high-rate capability in aqueous zinc ion batteries (AZIBs) are challenging. Herein, ultrathin hybrid nanobelts comprising single-crystalline VO2 and poly (3,4-ethylenedioxythiophene) (PEDOT) (designated as VO2-PEDOT) are synthesized as cathode materials for the AZIBs. The nanobelts have a thickness below 10 nm, large amount of exposed VO2 (001) facets and discrete PEDOT conductive layers. Systematic structural and electrochemical assessment reveals that simultaneous proton and Zn2+ insertion into the VO2 host is efficient in the Zn(CF3SO3)(2) electrolyte due to synergistic effects rendered by unique structure of the VO2-PEDOT nanobelts. The Zn/VO2-PEDOT battery that shows a storage mechanism involving two carriers delivers extraordinary performance including a high capacity of 540 mAhg(-1) with 36.3% beyond a high operating voltage of 0.7 V at 0.05 Ag-1, high rate capability of 231.2 mAhg(-1) at 10 Ag-1, excellent cycling stability up to 1000 cycles with capacity retention of 84.5%. Moreover, the 50 mu m thick freestanding electrode consisting of ultrathin VO2-PEDOT nanobelts has a large areal capacity of 1.35 mu Ahcm(-2) at 5 Ag-1. The results provide mechanistic insights into the electrochemistry of VO2-based cathodes and reveal a new strategy to improve the performance of the AZIBs especially with regard to grid-scale energy storage.