Almond gum based biopolymer electrolyte: A gateway to efficient lithium-ion conduction for supercapacitor application
摘要
This study focuses on analysing the transportation of lithium ions in Almond gum based solid biopolymer electrolyte (SBE). The SBE was prepared by a facile solution-casting technique. The prepared electrolyte was further analysed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transference number measurement (TNM), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and cyclic voltammetry (CV). XRD analysis revealed a gradual reduction in crystallinity as the salt concentration increased. FTIR spectroscopy established the existence of oxygen-rich functional groups that facilitate Li+ ion transport. EIS analysis at room temperature revealed that incorporating LiBr profoundly improved the ionic conductivity by five orders of magnitude from 5.35 × 10− 9 S cm− 1 (pristine sample LB0) to 2.91 × 10− 4 S cm− 1 (25 wt% of LiBr sample LB25). Transference number measurements further confirmed that ions are the dominant charge carriers, with a total ionic transference number of 0.91. The highest-conducting SBE exhibited an electrochemical stability window of up to 2 V. A symmetrical supercapacitor was constructed using activated carbon as the electrode material and the highest-performing SBE as the electrolyte. The CV analysis of the fabricated symmetrical supercapacitor exhibited no oxidation or reduction peaks, confirming a non-Faradaic charge storage mechanism. At a scan rate of 5 mV s− 1, the device delivered a specific capacitance of 20.32 F g− 1. GCD analysis showed a specific capacitance, energy, and power density of 21.12 F g− 1, 2.93 Wh Kg− 1, and 274.96 W Kg− 1, respectively.