• 文献标题:   Anomalous Capacitive Behaviors of Graphene Oxide Based Solid-State Supercapacitors
  • 文献类型:   Article
  • 作  者:   ZHANG Q, SCRAFFORD K, LI MT, CAO ZY, XIA ZH, AJAYAN PM, WEI BQ
  • 作者关键词:   graphene oxide, solidstate microcapacitor, laser reduction, diffusionles, classical molecular dynamic method
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Delaware
  • 被引频次:   40
  • DOI:   10.1021/nl4047784
  • 出版年:   2014

▎ 摘  要

Substantial differences in charge storage mechanisms exist between dielectric capacitors (DCs) and electrochemical capacitors (ECs), resulting in orders of magnitude difference of stored charge density in them. However, if ionic diffusion, the major charge transport mechanism in ECs, is confined within nanoscale dimensions, the Helmholtz layers and diffusion layers will overlap, resulting in dismissible ionic diffusion. An interesting contradiction between appreciable energy density and unrecognizable ionic diffusion is observed in solid-state capacitors made from reduced graphene oxide films that challenge the fundamental charge storage mechanisms proposed in such devices. A new capacitive model is proposed, which combines the two distinct charge storage mechanisms of DCs and ECs, to explain the contradiction, of high storage capacity yet undetectable ionic diffusion, seen in graphene oxide based supercapacitors.