Graphene shows unique electron-transport properties owing to the density of its carriers near the Dirac point. The quantum capacitance (CQ) of graphene is an intrinsic property that has been investigated theoretically in many previous studies. However, the development of CQ theory is hindered by the limited availability of related experimental works. In this perspective, experimental works on the CQ of mechanically exfoliated graphene, graphene synthesized by chemical vapor deposition (CVD), and graphene mesosponge are briefly summarized. The impact of structural properties such as stacking layers, defects, and nitrogen doping on CQ was experimentally investigated. Furthermore, the applicability of CQ theory was extended to three-dimensional graphene frameworks. Future research on CVD-synthesized and three-dimensional graphene is expected to enhance our comprehension of the underlying nature of CQ.

Evolution of the understanding of quantum capacitance through advancements in graphene-related carbon materials
    Abstract
    1 Introduction
    2 Mechanically exfoliated graphene
    3 Graphene synthesized by chemical vapor deposition
    4 Graphene mesosponge
    5 Summary
    References

• Rui Tang(College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha 410082, China) Corresponding author