Non-Faradaic-based supercapacitor fabricated with fish skin gelatin biopolymer electrolyte

Abstract

Fish gelatin (FS)–based polymer electrolytes doped with lithium perchlorate (LiClO4) are prepared via the solution cast method. The ionic conductivity of undoped pure FS film has been identified to be (9.29 ± 0.89) × 10-11 S cm-1 and increased to (3.58 ± 0.58) × 10-6 S cm-1 with the inclusion of 25 wt.% LiClO4 where this conductivity is mainly by ions due to the condition of te < ti. X-ray diffraction (XRD) analysis showed that 25 wt.% LiClO4 provides the most amorphous electrolyte. From the Fourier transform infrared (FTIR) spectroscopy, the shifting of amide A functional group peak indicates that cations from LiClO4 have formed interaction with the polymer. FS-LiClO4 electrolyte has been found to be electrochemically stable up to 1.88 V via linear sweep voltammetry (LSV). An electrical double-layer capacitor (EDLC) has been tested for 150 cycles where the specific capacitance at the 1st cycle is 28.2 F g-1.