Article

 

Design of aqueous redox-enhanced electrochemical capacitors with high specific energies and slow self-discharge Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/m613n030j

Descriptions

Attribute NameValues
Creator
Abstract
  • Electrochemical double-layer capacitors exhibit high power and long cycle life but have low specific energy compared with batteries, limiting applications. Redox-enhanced capacitors increase specific energy by using redox-active electrolytes that are oxidized at the positive electrode and reduced at the negative electrode during charging. Here we report characteristics of several redox electrolytes to illustrate operational/self-discharge mechanisms and the design rules for high performance. We discover a methyl viologen (MV)/bromide electrolyte that delivers a high specific energy of ~14 Wh kg⁻¹ based on the mass of electrodes and electrolyte, without the use of an ion-selective membrane separator. Substituting heptyl viologen for MV increases stability, with no degradation over 20,000 cycles. Self-discharge is low, due to adsorption of the redox couples in the charged state to the activated carbon, and comparable to cells with inert electrolyte. An electrochemical model reproduces experiments and predicts that 30–50 Wh kg⁻¹ is possible with optimization.
  • This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Nature Publishing Group. The published article can be found at: http://www.nature.com/ncomms/2015/150804/ncomms8818/full/ncomms8818.html
Resource Type
DOI
Date Available
Date Issued
Citation
  • Chun, S. E., Evanko, B., Wang, X., Vonlanthen, D., Ji, X., Stucky, G. D., & Boettcher, S. W. (2015). Design of aqueous redox-enhanced electrochemical capacitors with high specific energies and slow self-discharge. Nature Communications, 6, 7818. doi:10.1038/ncomms8818
Journal Title
Journal Volume
  • 6
Rights Statement
Funding Statement (additional comments about funding)
  • This work was supported by Advanced Research Projects Agency-Energy (ARPA-E), Department of Energy (DOE) of the United States (Award No. DE-AR0000344). D.V. acknowledges support from BioSolar Incorporation and the Swiss National Science Foundation (SNF-PBBSP2-144291). S.W.B. acknowledges support from the Research Corporation for Science Advancement as a Cottrell Scholar.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

Items