An electrical double-layer capacitor (EDLC) is a supercapacitor type that offers higher energy density and capacitance than an electrolytic capacitor. EDLC bridges the energy or power gap between the batteries, fuel cells, and dielectric capacitors. Most EDLCs are fabricated using electrolytic solutions, many of which are highly corrosive, leading to heavy, bulky, and leaky devices. This research assembled an EDLC employing a plasticised solid polymer electrolyte based on lithium iodide (LiI) doped corn starch. Glycerol was used as the plasticiser. The fabricated EDLC was characterised using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) techniques. The specific capacitance obtained from EIS was 1.74 F g–1. By analysing the Nyquist plot obtained from EIS, charge transfer resistance (Rct) and equivalent series resistance (ESR) were determined. CV of the EDLC was carried out at various sweep rates. The highest specific capacitance of 4.66 F g–1 was obtained at a 50 mV s–1 sweep rate. The EDLC was charged and discharged ten times at 1 mA constant current. From GCD, the specific capacitance was found to be in the 4.36 – 5.57 F g-1 range. From these results, starch-LiI-glycerol showed potential as a candidate for electrolyte material for energy device applications.Keywords: Electrolyte, electrical double-layer capacitor, glycerol, lithium iodide, solid polymer, starch, specific capacitance