Sudhakar, Y.N.Muthu, M.Bhat, D.K.2026-02-052015Materials for Renewable and Sustainable Energy, 2015, 4, 3, pp. -21941459https://doi.org/10.1007/s40243-015-0051-zhttps://idr.nitk.ac.in/handle/123456789/26228A new borax cross-linked biodegradable solid polymer electrolyte based on hydroxyethyl cellulose and phosphoric acid (H<inf>3</inf>PO<inf>4</inf>) was prepared. Characterizations of doped and undoped SPE were done using Fourier transform infrared spectroscopic and electrochemical studies. The ionic conductivity of the films increased with increase in acid concentration and the ionic conductivity obtained at 303 K was 4.1 × 10-3 S cm-1. Furthermore, effects of acid concentration on ionic conductivity and activation energy were discussed. Dielectric studies showed long tail-like feature indicating capacitive nature. A supercapacitor was fabricated and its electrochemical characteristics were studied. The supercapacitor showed a fairly good specific capacitance of 83 F g-1 at 2 mV s-1 and galvanostatic charge-discharge studies showed the mirror-like pattern with 98 % columbic efficiency. Cyclic stability was measured up to 2000 cycles. © 2015 The Author(s).Activation energyBiodegradable polymersBorate mineralsCelluloseCrosslinkingElectric dischargesElectrolytic capacitorsIonic conductivityPolyelectrolytesSodium borateSolid electrolytesSupercapacitorElectrochemical characteristicsElectrochemical studiesFourier transform infra redsGalvanostatic charge dischargesH3PO4Hydroxyethyl celluloseMethyl celluloseSolid polymer electrolytesPhosphoric acid