Comparison of Two-Dimensional Transition Metal Dichalcogenides for Electrochemical Supercapacitors
Comparison of Two-Dimensional Transition Metal Dichalcogenides for Electrochemical Supercapacitors
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DOI：
10.1016/j.electacta.2016.03.190
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发表时间：
2016-05-20
影响因子：
6.6
通讯作者：
Dryfe, Robert A. W.
中科院分区：
文献类型：
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作者：
Bissett, Mark A.;Worrall, Stephen D.;Dryfe, Robert A. W.
过渡金属二硫属化物 (TMDC) 等层状二维 (2D) 材料由于其高比表面积和多功能电子结构，在储能应用中受到越来越多的关注。在这项工作中，我们通过超声处理制备了各种少层厚 TMDC 晶体（MoS2、MoSe2、WS2 和 TiS2）的溶剂稳定分散体。首先通过多种技术对剥离材料进行表征以确定其质量。然后将这些分散体通过过滤用于形成超级电容器电极，而不使用任何其他导电添加剂或聚合物粘合剂。这些薄层 TMDC 电极被组装成对称纽扣电池装置，用于比较电化学测试。研究发现，尽管 MoS2 是研究最广泛的材料，但与高得多的电导率和较低密度的 TiS2 相比，MoS2 的电荷存储性能较差。阻抗谱用于研究纽扣电池内部的电荷存储机制，发现纽扣电池由快速但低强度的双电层电容和慢得多但高强度的离子吸附赝电容的组合组成。 (C) 2016 年作者。由爱思唯尔有限公司出版
Layered two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs) are receiving increased interest for applications in energy storage due to their high specific surface area and versatile electronic structure. In this work, we prepare solvent stabilised dispersions of a variety of few-layer thick TMDC crystals (MoS2, MoSe2, WS2, and TiS2) by ultrasonication. The exfoliated materials were first characterised by a variety of techniques to determine their quality. These dispersions were then used to form supercapacitor electrodes by filtration, without use of any further conductive additives or polymeric binders. These thin layer TMDC electrodes were assembled into symmetrical coin-cell devices for comparative electrochemical testing. It was found that despite being the most widely studied material, MoS2 suffers from inferior charge storage properties compared to the much higher conductivity and lower density TiS2. Impedance spectroscopy was used to investigate the charge storage mechanisms inside the coin cells, which were found to consist of a combination of both rapid, but low magnitude, electric double layer capacitance and much slower, but higher magnitude, ion adsorption pseudocapacitance. (C) 2016 The Authors. Published by Elsevier Ltd.