DOI: https://doi.org/10.55373/mjchem.v27i5.276

Keywords: Conductivity; dielectric permittivity; corn starch; polyvinyl alcohol

Abstract

Electrolytes are the critical determinant of the performance and efficiency of Electric Double‐Layer Capacitors (EDLCs). The current study addresses the analysis of solid polymer electrolytes for electrical and dielectric characteristics which were prepared from corn starch–polyvinyl alcohol (CS–PVA) blends doped with varying concentrations of lithium perchlorate, LiClO₄. In this regard, systematically evaluating the main parameters such as ionic conductivity, dielectric behavior and electrochemical stability is of utmost importance. These results showed that the enhancement of LiClO₄ concentration drastically changed the electrical properties of CS–PVA blends. Samples were prepared and were tested. The mixture with 70 wt.% LiClO₄ had the maximum ionic conductivity with a value of 2.58 × 10⁻³ S/cm at room temperature. This improvement has been attributed to the higher mobility of mobile carrier ions as well as to better segmental motion inside the polymer matrix. Dielectric analysis revealed that the sample containing a higher LiClO4 addition displayed a lower relaxation time, as well as an increased dielectric constant, indicating improved ion mobility inside the polymer matrix. The loss tangent values suggested an increased segmental motion of polymer chains with increasing content of LiClO4 in turn affecting the charge transport. Linear sweep voltammetry (LSV) was carried out to verify the electrochemical stability of this optimized electrolyte, which can sustain a potential window of 2.93 V and the measured ion transference number (TNM) achieved 0.87 showing that ionic conduction is still the main mechanism in this case. The results demonstrate the feasibility of using LiClO4 doped CS–PVA SPE as a promising biodegradable material for EDLCs applications with extensive highlights on its great electrochemical properties needed for ion transportability, high conductivity and good electrochemical stability.