Abstract
Simple and easily integrated design of flexible and transparent electrode materials affixed to polymer-based substrates hold great promise to have a revolutionary impact on the functionality and performance of energy storage devices for many future consumer electronics. Among these applications are touch sensors, roll-up displays, photovoltaic cells, health monitors, wireless sensors, and wearable communication devices. Here, we report an environmentally friendly, simple, and versatile approach to produce optically transparent and mechanically flexible all-solid-state supercapacitor devices. These supercapacitors were constructed on tin-doped indium oxide coated polyethylene terephthalate substrates by intercalation of a polymer-based gel electrolyte between two reduced graphene oxide (rGO) thin-film electrodes. The rGO electrodes were fabricated simply by drop-casting of graphene oxide (GO) films, followed by a novel low-temperature (≤250 °C) vacuum-assisted annealing approach for the in situ reduction of GO to rGO. A trade-off between the optical transparency and electrochemical performance is determined by the concentration of the GO in the initial dispersion, whereby the highest capacitance (∼650 μF cm-2) occurs at a relatively lower optical transmittance (24%). Notably, the all-solid-state supercapacitors demonstrated excellent mechanical flexibility with a capacity retention rate above 90% under various bending angles and cycles. These attributes underscore the potential of the present approach to provide a path toward the realization of thin-film-based supercapacitors as flexible and transparent energy storage devices for a variety of practical applications.
Original language | English |
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Pages (from-to) | 11008-11017 |
Number of pages | 10 |
Journal | ACS Applied Materials and Interfaces |
Volume | 10 |
Issue number | 13 |
DOIs | |
State | Published - Apr 4 2018 |
Funding
Research (T.A., C.M.R., W.H., S.M.M., R.T.M., Z.D.H., T.K., and P.C.J.) was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract no. DE-AC05-00OR22725. XPS research was supported (G.M.V.) by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. A portion of this research is supported by DOE Office of Energy Efficiency and Renewable Energy’s Building Technologies Office under Sensors and Controls Subprogram. Other portions of this research were completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Z.D.H. gratefully acknowledges support from the National Science Foundation Graduate Research Fellowship under grant no. DGE-1650044 and the Georgia Tech-ORNL Fellowship. Support for M.S.R., W.H., and F.G.B. was provided in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship program.
Keywords
- flexible electrode
- graphene oxide
- optically transparent
- supercapacitor
- thin film