Electric double layer capacitor based on activated carbon electrode and biodegradable composite polymer electrolyte

A series of polymer electrolyte based on poly(vinyl alcohol), lithium perchlorate (LiClO₄), and antimony trioxide (Sb₂O₃) was prepared via solution casting technique with distilled water as solvent. The dielectric behavior study reveals the non-Debye properties of the polymer electrolytes. In frequency dependence conductivity measurement, dispersion at low frequency was due to the interfacial resistance and space charge polarization inside the polymer electrolytes. The linear sweep voltammetry has proven that the incorporation of Sb₂O₃ into polymer matrix increases the maximum operational potential region. Electric double-layer capacitors (EDLCs) based on activated carbon electrode assembled with solid polymer electrolyte and composite polymer electrolyte has been evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge technique. CV test disclosed rectangular shapes with slight distortion, and there is no evidence for any redox currents on both anodic and cathodic sweeps, which indicates the typical behavior of EDLC. Both EDLC cells demonstrate good cyclability throughout 200 cycles with specific capacitance retention more than 90 %.