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This content will become publicly available on April 27, 2017

Title: Pseudocapacitance and excellent cyclability of 2,5-dimethoxy-1,4-benzoquinone on graphene

Electrochemically active organic materials are emerging as low cost, naturally abundant and sustainable alternatives to their metal-based counterparts. However, their usage in energy storage systems is mainly hindered by their poor conductivity, which results in capacitance fade upon cycling. In this paper, we present a redox-active xerogel composed of 2,5-dimethoxy-1,4-benzoquinone (DMQ) decorated on reduced graphene oxide (rGO) sheets via a hydrothermal method as a high capacitance and long cycle life pseudocapacitive electrode. DMQ not only provided stable redox-active centers but also served as a spacer to avoid rGO sheets aggregation and led to a three-dimensional (3D) hierarchical electrode architecture. When a binder-free 50 μm thick rolled film was tested as a pseudocapacitive electrode, it exhibited an excellent capacitance of 650 F g-1 at 5 mV s-1 (780 F cm-3) in 1 M sulfuric acid, outperforming a large number of reported organic and inorganic electrodes. Most importantly, optimized electrodes showed an excellent capacitance retention of 99% after 25 000 cycles at 50 mV s-1. Density functional theory (DFT) calculations are further used to understand the charge storage mechanism, the preferred orientation of the adsorbed molecules, charge density distribution and density of states. In conclusion, our combined experimental and theoretical findings demonstratemore » that the careful selection of the conductive substrate, electrode architecture and organic molecules plays a crucial role in achieving high capacitance and long cycling performance.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [1]
  1. Drexel Univ., Philadelphia, PA (United States)
  2. Drexel Univ., Philadelphia, PA (United States); Huazhong University of Science and Technology, Wuhan (China)
  3. University of Picardie Jules Verne, Amiens (France); ; Centre National de la Recherche Scientifique (CNRS) (France)
  4. Huazhong University of Science and Technology, Wuhan (China)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Energy & Environmental Science
Additional Journal Information:
Journal Volume: 9; Journal Issue: 8; Journal ID: ISSN 1754-5692
Royal Society of Chemistry
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States