Flexible solid-like electrolytes with ultrahigh conductivity and their applications in all-solid-state supercapacitors

• Main Authors: Kumar, A. (Author), Lin, H.-Y (Author), Pattanayak, B. (Author), Tsai, H.-Y (Author), Tseng, T.-Y (Author), Winie, T. (Author), Yang, C.-C (Author)
• Format: Article
• Language: English
• Published: Royal Society of Chemistry 2018
• Subjects: All-solid-state supercapacitors; Capacitance; Charging/discharging; Electrodes; Electrolytic capacitors; Ethylene; Ethylene carbonate; Fluorine compounds; Ionic conduction in solids; Maximum power density; Multiwalled carbon nanotubes (MWCN); Poly(vinylidene fluoride-co-hexafluoropropylene); Polyvinylidene fluorides; Solid electrolytes; Solid-state electrolyte; Specific capacitance; Supercapacitor; Yarn
• Online Access: View Fulltext in Publisher; View in Scopus

 All-solid-state supercapacitors (ASSS) with solid-state electrolytes (SSEs) can be used to overcome the liquid leakage problem in devices. However, ionic conduction in solid electrolytes is one of the barriers to further improvements in ASSS. This paper describes the fabrication of a flexible SSE composed of poly(vinylidene fluoride-co-hexafluoropropylene), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and ethylene carbonate, which demonstrates an ultrahigh conductivity of 8.52 mS cm-1 and a wide 5 V operation voltage window of -2 to +3 V. Electrodes composed of active carbon, multiwall carbon nanotubes, and polyvinylidene fluoride were used as both anode and cathode to assemble a symmetrical supercapacitor. The resultant supercapacitor exhibits a maximum power density of 3747 W kg-1 at an energy density of 7.71 W h kg-1 and a maximum energy density 17.1 W h kg-1 at a power density of 630 W kg-1. It displays excellent cycling stability with 91.3% of the initial specific capacitance after 3000 charging/discharging cycles. This flexible SSE in this study demonstrates a high potential for use in energy storage, conversion, and wearable device applications. © 2018 The Royal Society of Chemistry.