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 (σDC = 1.2 mS cm−1 at 25 °C), high dielectric constant (εs = 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.