Improved polymer chain movement in Poly(Vinyl Alcohol)–Potassium hydroxide gel polymer electrolytes with nanostructured Cobalt(II,III) oxide fillers for supercapacitor

Designing high-performance polymer-based electrolytes is crucial for enhancing the conductivity of electrochemical capacitors. In this study, a highly conductive polymer/inorganic hybrid electrolyte was developed to improve the ionic conductivity by increasing the free volume between the polymer chains. The filler promotes the movement of OH⁻ ions in the polymer gel electrolyte and enhances the device performance by facilitating the rapid movement of the polymer chains. In particular, rod-like or other similarly shaped fillers promote the formation of ionic conduction networks to improve the ionic conductivity. The use of the urchin-shaped Co₃O₄ (U–Co₃O₄) filler (4 wt%) facilitates a high ionic conductivity of 2.61 × 10⁻² S cm⁻¹ at room temperature because the U–Co₃O₄ surface acts as a conductive network in the polymer matrix contributing to the rapid ionic transport. Therefore, an optimal filler morphology is for increasing the performance of gel polymer electrolytes.