Printable multi-walled carbon nanotubes thin film for high performance all solid state flexible supercapacitors

Abstract

All-solid-state flexible supercapacitor is assembled using multi-walled carbon nanotubes (MWCNT) and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] based gel polymer electrolyte. Flexible electrodes on polyethylene-terephthalate (PET) substrate were made by inkjet printed azide functionalized MWCNT (f-MWCNT), serving both as electrodes and charge collector. Fabricated supercapacitor f-MWCNT/gel polymer electrolyte/f-MWCNT (f-MWCNT SC) demonstrated high power and energy performance as a gel polymer electrolyte based all solid-state flexible supercapacitor. f-MWCNT SC demonstrates high specific capacitance 235F/g at 5mV/s in wide operating potential range of 3V. Short relaxation time constant (Ͽo) (248ms) with high apparent diffusion coefficient (Da) 2.25ÿ10⿿8cm2/s resulted in very high energy density 16.2Wh/kg and power density 45kW/kg at 1A/g. f-MWCNT SC exhibits high flexibility and excellent cycling stability with capacity retention >90% after 5000 galvanostatic charge discharge cycles.