3 years ago

Substrate Effects in Graphene-Based Electric Double-Layer Capacitors: The Pivotal Interplays between Ions and Solvents

Substrate Effects in Graphene-Based Electric Double-Layer Capacitors: The Pivotal Interplays between Ions and Solvents
Kefa Cen, Zheng Bo, Jing Kong, Huachao Yang, Jianhua Yan, Xia Chen, Jinyuan Yang
Graphene has been considered as a promising active material for electric double-layer capacitors (EDLCs), primarily owing to its extraordinary monolayer properties, whereas the interfacial behaviors are conspicuously impacted by underlying substrates. In this work, substrate effects on the interfacial wettability, EDL structure, and capacitive behavior of graphene-based EDLCs are delineated with numerical simulation. Unlike previous studies, a partial wetting transparency of topmost graphene is recognized for hydrophilic supports. In particular, a virtually identical capacitance is demonstrated for graphene with various supports, albeit the substantially different EDL structures stemmed from substrate effects. The achieved invariant capacitance is prominently attributed to the counterbalancing correlations between ions and proximal solvents, going beyond traditional views of modulating capacitance preferentially through ion structural evolutions. Specifically, the suppressed permittivity of apparently ordered water dipoles (i. e. detrimental solvent effects) attenuates the beneficial ionic influences (i. e. reinforced population and closer approach) on shielding the external electric fields. The as-obtained findings demonstrate the paramount importance of the substrate in mediating interfacial behaviors within electrified EDLC systems and highlight that exploiting the pivotal interplay between ions and solvents could be a novel avenue to further manipulate electrochemical performances. Evaluation of substrate effects: The influences of substrate on interfacial structure and capacitive behavior of graphene-based supercapacitors are demonstrated with numerical simulation. A partial wetting transparency of graphene is observed. Unusually, an analogous capacitance is recognized, albeit with strikingly different electrolyte structures. The pivotal interplays between ions and solvents in mediating the capacitance are demonstrated, going beyond traditional views.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/celc.201700733

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.