(a) HOMO and LUMO energy levels of polymer monomers, plasticizers, and lithium salts. (b) ESP of PEGDA, HFBA, FEC, EC, and EMC. (c) Electron localization function of POSS, HFBA, and PEGDA. (d) Schematic diagrams of gel polymerization for HP and HPP. (e) Schematic representation of the three-dimensional gel structure of HPP and its internal cross-linked network. (f) Photos of HP and HPP polymers before and after combustion.