• 文献标题:   Molecular Origin of Electric Double-Layer Capacitance at Multilayer Graphene Edges
  • 文献类型:   Article
  • 作  者:   YANG HC, ZHANG XL, YANG JY, BO Z, HU M, YAN JH, CEN KF
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICAL CHEMISTRY LETTERS
  • ISSN:   1948-7185
  • 通讯作者地址:   Zhejiang Univ
  • 被引频次:   22
  • DOI:   10.1021/acs.jpclett.6b02659
  • 出版年:   2017

▎ 摘  要

Multilayer graphenes have been widely used as active materials for electric double-layer capacitors (EDLCs), where their numerous edges are demonstrated to play a crucial role in charge storage. In this work, the interfacial structure and capacitive behaviors of multilayer graphene edges with representative interlayer spacing are studied via molecular dynamics (MD) simulations. Compared with planar graphite surfaces, edges can achieve a 2-fold increase in the specific capacitance at a wider interlayer spacing of similar to 5.0 angstrom. Unusually, the molecular origins for achieved charge storage are predominantly attributed to the structural evolutions of solvents occurring in the double layer, going beyond the traditional views of regulating the capacitance by ion adsorption/separation. Specifically, diverse ionic distributions exhibit similar screening ability and EDLC thickness, while water molecules can counterbalance the interfacial electric fields more effectively at edge site. The as-obtained findings will be instructive in designing graphenebased EDLCs for advanced capacitive performances.