物理化学学报 >> 2020, Vol. 36 >> Issue (2): 1905032.doi: 10.3866/PKU.WHXB201905032

所属专题: 超级电容器

综述 上一篇    下一篇

二维纳米片层孔洞化策略及组装材料在超级电容器中的应用

康丽萍,张改妮,白云龙,王焕京,雷志斌,刘宗怀*()   

  • 收稿日期:2019-05-07 录用日期:2019-06-04 发布日期:2019-06-10
  • 通讯作者: 刘宗怀 E-mail:zhliu@snnu.edu.cn
  • 作者简介:刘宗怀,陕西师范大学教授,生于1963年。2001年日本德岛大学工学部获得物质工学博士学位;2001–2004年日本学术振兴会博士后研究;2004年回国在陕西师范大学任教授,博士生导师。主要从事二维层状材料剥离及新型储能材料在超级电容器方面应用研究。
  • 基金资助:
    国家自然科学基金(21471093);国家自然科学基金(51772182);111引智项目支持

Two-Dimensional Nanosheet Hole Strategy and Their Assembled Materials for Supercapacitor Application

Liping Kang,Gaini Zhang,Yunlong Bai,Huanjing Wang,Zhibin Lei,Zonghuai Liu*()   

  • Received:2019-05-07 Accepted:2019-06-04 Published:2019-06-10
  • Contact: Zonghuai Liu E-mail:zhliu@snnu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21471093);the National Natural Science Foundation of China(51772182);the 111 Project

摘要:

功率密度高、倍率性能优异和循环性能好等特性使得超级电容器在储能领域显示了巨大的应用前景。尽管二维层状材料剥离形成的纳米片层不仅可为电化学反应提供独特的纳米级反应空间,而且由其组装的层状纳米电极材料具有化学和结构上的氧化还原可逆性及纳米片层水平方向上离子或电子快速传输通道。但是,纳米片层组装电极材料在纳米片层垂直方向上离子或电子传输存在障碍,对于超级电容器功率密度和能量密度的提高及实现快速能量储存非常不利。因此,如何通过改善离子或电子的快速传输,实现超级电容器大功率密度下的高能量密度是超级电容器电极材料发展的方向之一。本文主要综述了二维层状材料剥离成纳米片层,纳米片层孔洞化策略及组装孔洞化材料在超级电容器电极材料中的应用。纳米层孔洞化技术是改善层状电极材料在纳米片层垂直方向离子或电子传输的有效手段,为实现高比电容下的高倍率性能超级电容器电极材料制备提供了方法学。最后,对开发大功率密度下的高能量密度超级电容器电极材料提出了展望。

关键词: 二维层状材料, 剥离, 纳米层孔洞化, 孔洞电极材料, 超级电容器

Abstract:

Owing to their high power density, excellent rate performance, and good cycle performance, supercapacitors are widely used for energy storage applications. Two-dimensional (2D) layered materials are structural compounds having a layered host structure with a layer thickness of nanometers and a lateral dimension of several micrometers. Their layer spacing can be controlled by changing the interaction between the layers. 2D layered materials can be delaminated into nanosheets. Exfoliated nanosheet materials provide a new strategy for improving the performance of supercapacitors. Unlike bulk layered materials, the exfoliated nanosheets not only provide a unique nano-scale reaction space for electrochemical reactions, but also offer the possibility for improving the specific capacitance and storage rate of the supercapacitor. However, in 2D layered materials, the ion or electron transport in the vertical direction is obstructed, despite their fast ion and electron transport in the horizontal direction. As a result, the occurrence of electrode reactions, and hence the realization of rapid storage become difficult. It is detrimental to the power and energy densities and rapid energy storage of supercapacitors. Therefore, it is imperative to develop novel electrode materials in order to fabricate supercapacitors showinghigh energy densities at high power densities.

Porous 2D layered electrode materials offer two major advantages. First, the porous structure can alleviate the problems caused by the stacking of nanosheets during the assembly process. Second, the porous structure can effectively promote the electrolyte penetration of the electrode, which alleviates the volume changes of the electrode material during the charging-discharging process and releases the structural strain. Hence, such materials facilitate ion or electron transport, thus increasing the specific capacitance of the supercapacitor. Over the past few years, 2D nanosheet holeization has evolved as a promising approach to improve the energy density of supercapacitors at high power densities. Various porous 2D layered supercapacitor electrode materials have been developed. This paper reviews the exfoliation of 2D layered materials, nanosheet holeization strategy, and the application of assembled porous layered electrode materials in supercapacitors. In this paper, we have reviewed the exfoliation of 2D layered materials with different electric properties and the performance of 2D nanosheets. Different methods used for the preparation of holey 2D nanosheets have also been discussed. We prepared holey MnO2 nanosheets and reduced graphite oxide via redox holeization mechanism, and 2D porous nanomaterials were also prepared by using suitable templates such as hard or self-sustaining templates. These holey 2D nanosheets were used to prepare porous 2D layered electrode materials such as holey graphene/manganese dioxide composite fibers and holey graphene/polypyrrole hybrid aerogels. The capacitance of these electrode materials was investigated systematically. Finally, the prospects for the development of porous 2D layered electrode materials such as the optimization of theirrate performance, flexibility, and energy density were discussed. Novel holeization methods should be developed in order to prepare metal oxide nanosheets with controllable hole sizes. In addition, other 2D materials such as MXene should be explored.

Key words: Two-dimensional layered material, Delamination, Nanosheet holeization, Holey electrode material, Supercapacitor

MSC2000: 

  • O646