(2 × 4)-Type tetra-PEG ion gels were prepared through a copper-free azide–alkyne cycloaddition reaction between tetra-branched poly(ethylene glycol) and linear tetra(ethylene glycol). The tensile tests showed that the reaction efficiency of the cross-linking was over 90%. The prepared ion gels exhibited high mechanical toughness and stretchability characteristic of tetra-PEG gels. The electrochemical window of the ion gels was the same as that of the ionic liquid inside the gel. The ionic conductivity of the ion gel (30 wt% polymer concentrations) was 8.9 × 10−4 S cm−1 (25 °C, anhydrous conditions).
