• 文献标题:   Capacitance of edge-free three-dimensional graphene: New perspectives on the design of carbon structures for supercapacitor applications
  • 文献类型:   Article
  • 作  者:   TANG R, NOMURA K, INOUE K, KOTANI M, KYOTANI T, NISHIHARA H
  • 作者关键词:   quantum capacitance, threedimensional graphene, supercapacitor, templated carbon, chemical vapor deposition
  • 出版物名称:   ELECTROCHIMICA ACTA
  • ISSN:   0013-4686 EI 1873-3859
  • 通讯作者地址:  
  • 被引频次:   2
  • DOI:   10.1016/j.electacta.2022.141009 EA AUG 2022
  • 出版年:   2022

▎ 摘  要

The current target for expanding the application scope of supercapacitors is to increase their energy density (E) beyond 20 Wh kg-1. In this regard, edge-free carbon materials show considerable potential because of their high working voltage (U) in organic electrolytes; however, their capacitance (C) remains limited. In this study, we synthesized edge-free three-dimensional (3D) graphene materials with different numbers of graphene stacking layers (nstack). These carbon materials have similar pore morphologies and an edge-free structure because a template method and annealing at 1800 & DEG;C were applied, respectively. These features allowed C to remain unaffected by the pore size effect, wettability, parasitic side reactions, and pseudocapacitance. Our results suggested that increasing nstack slightly enhances the areal C; however, such an increase cannot compensate for the decrease in C attributed to the decrease in the specific surface area. We also confirmed that the C of 3D graphene materials has a quantum origin, which results in a "butterfly shaped " cyclic voltammetry curve; we also successfully quantified the quantum capacitance (CQ) for the complete understanding of the origin of C. Based on this knowledge, we estimated that this 3D graphene material can yield a high E of 43 Wh kg-1 once CQ is optimized.