Biobased epoxy resins from cardanol for potassium-ion conducting gel polymer electrolytes

In this work, biobased membranes were developed for potential application as gel polymer electrolytes (GPEs) for potassium ion batteries (KIBs). The proposed membranes were crosslinked via ring-opening reaction of a cardanol-derived epoxy resin with glutaric, succinic and hexahydro-4-methylphthalic anhy-dride. The curing time and temperature and the reaction kinetic were studied by non-isothermal differential scanning calorimetry. Gravimetric gel content measurements and dynamic mechanical thermal analysis confirmed the high-network connectivity of such biobased membranes.The electrochemical characteriza-tion perfomed on such systems reported excellent swelling performances, electrochemical stability towards potassium metal and suitable ionic conductivity (10‒3 S cm‒1 ) at room temperature.