화학공학소재연구정보센터
Chemical Engineering Journal, Vol.258, 320-326, 2014
Ionic liquid-gelled polyvinylidene fluoride/polyvinyl acetate polymer electrolyte for solid supercapacitor
A promising ionic liquid-gelled polymer electrolyte (GPE) based on semi-crystal polyvinylidene fluoride (PVDF), amorphous polyvinyl acetate (PVAc) and ionic conductive 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) is successfully prepared via solution-casting method. The structures and morphologies of the GPEs are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the thermal stability of the GPEs is measured by thermogravimetric/differential scanning calorimetry (TG/DSC). Highly homogenous, translucent, and flexible GPE films are easily obtained by adjusting the ionic liquid (IL) contents. The PVDF/PVAc/IL (IL, 50 wt%) GPE film presents good thermal stability (similar to 300 degrees C), wide electrochemical window (>4.0 V), and acceptable ionic conductivity (2.42 x 10(-3) S cm(-1) at room temperature) as well. A 3.0 V C/C solid-state capacitor cell using this GPE film was assembled and measured. It is found that the capacitor cell shows specific capacitance of 93.3 F g(-1) (based on activated carbon) at the current density of 200 mA g(-1), and can retain more than 90% of the initial capacitance after 5000 charge-discharge cycles. (C) 2014 Elsevier B.V. All rights reserved.