In Situ Polymerization of Xanthan/Acrylamide for Highly Ionic Conductive Gel Polymer Electrolytes with Unique Interpenetrating Network

Gel polymer electrolyte (GPE) is the key to assembling high-performance solid-state supercapacitors (SSCs). Poly­(acrylamide) (PAM) is considered as an important GPE matrix because of its good water solubility, the ease of hydrogen bond formation, and its excellent gel properties. However, the high crystallinity of linear polymer PAM impedes ion migration, and PAM has high flammability in air, which may cause safety problems. In this work, xanthan/PAM-based GPE (XP-GPE) was successfully prepared by an in situ polymerization method. Xanthan and linear PAM chain can form a dual network by hydrogen bond forming between the amide group of PAM and the hydroxyl group of xanthan. This greatly reduces the high crystallinity of PAM macromolecule, realizes the active migration of lithium ion between chain segments, and improves the electrochemical performance. SSCs prepared with XP-GPE and activated carbon electrodes show excellent specific capacitance (589 mF cm–2 at current density of 5 mA cm–2) and ionic conductivity (46.96 mS cm–1). Furthermore, the SSC shows outstanding flame retardant property. And the electrochemical performance of the flexible SSC has little change under bending conditions, providing an opportunity to develop safe and efficient flexible wearable SSCs.