Thymol and Nickel Chloride Boost Ionic Conductivity in PVA Electrolytes for Low-Voltage Storage

Researchers developed solid polymer electrolyte films from polyvinyl alcohol, thymol plasticizer, and nickel chloride. The best formulation reached an ionic conductivity of 9.45 x 10^-6 S/cm with an ion transference number of 0.964, meaning charge moves mostly through ions rather than electrons. FTIR and dielectric measurements confirmed polymer-salt complex formation and interfacial polarization effects. The tradeoff is clear: adding nickel chloride raised conductivity but lowered thermal stability, and the electrochemical stability window stayed at 1.92 V. That keeps these films in low-voltage energy storage territory, not high-voltage solid-state batteries. The authors position the work as a baseline for bio-based, plasticized PVA electrolytes, which is a fair reading of the results.