Adsorption of metal atoms on silicene: stability and quantum capacitance of silicene-based electrode materials

Abstract

Metal-doping with the formation of a metal–vacancy complex results in an obvious increase of silicene's quantum capacitance.

Engineering 2D Materials: A Viable Pathway for Improved Electrochemical Energy Storage

“…[106][107][108] Similar chemical doping (e.g., B, P, S, and F) was also investigated to enhance the power performance via improving the surface pseudocapacitance [109] and quantum capacitance, [110] regulating interface compatibility, [109] enlarging potential window and so on. [111][112][113][114][115][116][117][118][119][120][121][122][123][124][125][126] Like in the case of graphene, chemical doping of other 2D materials can also regulate the energy storage performance.…”

“…There are several ways that chemical doping could offer to contribute to the improvement in energy storage performance, including the pseudocapacitance (with new redox active center), boosted charge mobility and DOS at the Fermi level (e.g., charge charrier density, the C q in Equations (2) and (3), a new gap to give quantum capacitance ( C tot increased, Equation (2)), the increased interlayer spacing to improve ion accessibility and C dielec ( C tot increased, Equation (2)), the enhanced stability, and the newly formed charge injection to improve binding ability with ions (reducing the d in Equation (1)). [ 101–126 ] A quick instance is O functional groups on graphene's surface, which offer additional pseudocapacitance. Nevertheless, these O‐functionalized groups are generally unstable, reducing the charge mobility of graphene.…”

2 D Materials for Electrochemical Energy Storage: Design, Preparation, and Application

“…However, recent reports have shown that the electronic density of states (DOS) of electrode materials has as ignificant influence on the total capacitance (C tot ), in contrast to electric double-layer capacitance (C EDL ). [19] Thisc apacitance from the low DOS of the electrode is called quantum capacitance (C Q ) which can be directly achieved from electronic structure computations. For example, graphene can produce C Q easily when used as the electrode material in EDLCs.…”

Design, characterization, and application of elemental 2D materials for electrochemical energy storage, sensing, and catalysis

“…Among other group IV elemental 2D materials, silicene has been investigated using density functional theory (DFT). 195,196 With the first-principles theory, it was shown that the quantum capacitance of silicene was larger than that of graphene due to the lower Fermi velocity near the Dirac point. Furthermore, the introduction of defects with doping could be utilized to increase the quantum capacitance.…”