A stretchable, fully self-healable, temperature-tolerant, and water-proof supercapacitor using TUEG₃ capped gold nanosheets on oxime-carbamate bonded polyurethane film and organohydrogel

In this study, we demonstrate a stretchable, fully self-healable, temperature-tolerant, and water-proof supercapacitor with high electrochemical performance via a deliberate selection of materials and device architecture. Distinct from previous works, our whole supercapacitor is stretchable and self-healable, owing to the application of specially devised stretchable and self-healing oxime-carbamate based polyurethane (OC-PU) substrate film, self-healing polymer (poly(ether-thioureas) triethylene glycol) capped Au nanosheet current collector (TUEG₃-Au NS) and newly synthesized organohydrogel electrolyte. The fabricated supercapacitor exhibits a high electrochemical performances (specific capacitance of 1650.5F g⁻¹, energy density of 14.58 Wh kg⁻¹, power density of 2181.75 W kg⁻¹, and capacitance retention of 89 % after 10,000 cycles) with a capacitance retention of 81 % over stretching by 40 % even after repetitive healing from damages, the self-healing of all components (full self-healing) over repetitive damages with a capacitance recovery by over 83 %, a wide operational temperature range from −20 to 60 °C with retaining over 91 % of capacitance at RT. Furthermore, a μ-LED is stably operated with the supercapacitor immersed in water regardless of the mechanical deformation and self-healing from damage due to self-bonded encapsulation layer of hydrophobic OC-PU film. With a vertically integrated patch device consisting of the fabricated supercapacitor and a strain sensor, bio-signals are detected using the stored energy of the supercapacitor even after self-healing from damages over the temperature range from −20 to 60 °C. This work suggests the high application potential of our high performance multi-functional supercapacitor as an integrated energy storage device for wearable electronics featuring longevity and stability under harsh environments.