Self‐Healing and Shape‐Editable Wearable Supercapacitors Based on Highly Stretchable Hydrogel Electrolytes

Abstract

Shape editability combined with a self‐healing capability and long‐term cycling durability are highly desirable properties for wearable supercapacitors. Most wearable supercapacitors have rigid architecture and lack the capacity for editability into desirable shapes. Through sandwiching hydrogel electrolytes between two electrodes, a suite of wearable supercapacitors that integrate desirable properties namely: repeated shape editability, excellent self‐healing capability, and long‐term cycling durability is demonstrated. A strategy is proposed to enhance the long‐term cycling durability by utilizing hydrogel electrolytes with unique cross‐linking structures. The dynamic crosslinking sites are formed by quadruple H bonds and hydrophobic association, stabilizing the supercapacitors from inorganic ion disruption during charge–discharge processes. The fabricated supercapacitors result in the capacitance retention rates of 99.6% and 95.8% after 5000 and 10 000 charge–discharge cycles, respectively, which are much higher than others reported in the literature. Furthermore, the supercapacitor sheets can be repeatedly processed into various shapes without any capacitance loss. The supercapacitors exhibit a 95% capacitance retention rate after five cutting/self‐healing cycles, indicative of their excellent self‐healing performance. To demonstrate real‐life applicability, the wearable supercapacitors are successfully used to power a light‐emitting diode and an electronic watch.

Hydrogel with Robust Adhesion in Various Liquid Environments by Electrostatic‐Induced Hydrophilic and Hydrophobic Polymer Chains Migration and Rearrangement

“…Furthermore, the loss factor of tanδ in the rotation speed range of 0.1-100 rad s −1 showed a relatively low dependence on frequency for the hydrogel with low PTA amount, indicating its better fatigue resistance (Figure S4, Supporting Information). [24] Excess PTA made the hydrogel (PTA amount of 100%) completely white, with a thick dense outer layer and internal dense sandwich layer (Figure S5, Supporting Information). These results suggest that PTA can significantly enhance the strength of the hydrogel by increasing the cross-link density, which significantly affects the adhesion properties.…”

Triboelectric Nanogenerators Based on Super-Stretchable Conductive Hydrogels with the Assistance of Deep-Learning for Handwriting Recognition

“…In consequence, it is imminent to investigate high-quality materials for flexible TENGs. , Compared to conventional metal electrodes, electroactive hydrogels have become emerging flexible materials due to their excellent tensile strength, favorable biocompatibility, and electrical conductivity. They have been applied to electronic products such as supercapacitors, wearable biosensors, hydrogel strain sensors, and TENGs. − As a typical solid soft material, a hydrogel is abound with a significant amount of free water, where a 3D crosslinked hydrophilic polymer chain net acts as a skeleton frame. The electrical conductivity of hydrogels can be controlled by introducing appropriate conductive composites into the hydrogel substrate.…”

Swelling-resistant microgel-reinforced hydrogel polymer electrolytes for flexible all-in-one supercapacitors with high performances

“…[1][2][3][4][5] Although batteries are widely used as power sources for electronic devices due to their excellent energy density, supercapacitors are emerging as promising energy storage devices for portable function-integrated electronics due to their advantages of high-power density, long cycle life, fast charge/discharge, good safety and miniaturization. [6][7][8][9] Especially, all-in-one supercapacitors, a class of integrated supercapacitors with low interfacial resistance and mechanical stability under complex deformation, have received extensive attention. [10][11][12] Currently, in situ polymerization of polyaniline (PANI) or polypyrrole (PPy) on a hydrogel polymer electrolyte (HPE) is performed to fabricate flexible all-in-one supercapacitors.…”