Multi‐Foldable and Environmentally Stable All‐Solid‐State Supercapacitor Based on Hierarchical Nano‐Canyon Structured Ionic‐Gel Polymer Electrolyte

Abstract New ionic‐gel polymer electrolytes (IGPEs) are designed for use as electrolytes for all‐solid‐state supercapacitors (ASSSs) with excellent deformability and stability. The combination of the photochemical reaction‐based polymer matrix, weak‐binding lithium salt with ionic liquid, and ion dissociating solvator is employed to construct the nano‐canyon structured IGPE with high ionic conductivity (σ DC = 1.2 mS cm −1 at 25 ° C), high dielectric constant (ε s = 131), and even high mechanical robustness (bending deformation for 10 000 cycles with superior conductivity retention [ ≈ 91%]). This gives rise to ASSS with high compatibility and stability, which is compliant with foldable electronics. Consequently, this ASSS delivers remarkable electrochemical performance (specific capacitance of ≈ 105 F g −1 at 0.22 A g −1 , maximum energy density and power density of 23 and 17.2 kW kg −1 ), long lifetime ( ≈ 93% retention after 30 days), wider operating temperature ( ≈ 0–120 ° C), and mechanical stabilities with no significant capacitance reduction after mechanical bending and multiple folding, confirming the superior electrochemical durability under serious deformation states. Therefore, this ultra‐flexible and environmentally stable ASSS based on the IGPE having the nano‐canyon morphology can be a novel approach for powering up the ultra‐deformable and durable next‐generation wearable energy storage devices.