A Self-healing Hydrogel Electrolyte Towards All-in-one Flexible Supercapacitors

The autonomously self-healable all-in-one supercapacitor is prepared by in situ rapid polymerization of electrode materials on the surface of self-healing poly (vinyl alcohol) (PVA) hydrogel electrolyte containing sulphuric acid (H2SO4). The self-healing PVA electrolyte has been achieved by physical interaction, in which dynamic hydrogen bonds between PVA chains can readily break and reform, allowing PVA hydrogel electrolyte to self-heal and regain its mechanical and electrochemical properties. The obtained PVA hydrogel displays fast self-healing capability, reliable mechanical performance (stress at 290 KPa after stretching to 238 %) and high ionic conductivity (57.8 mS cm− 1). Based on these excellent properties, an all-in-one supercapacitor with self-healing characteristics is assembled by in situ polymerization of aniline on the surface of self-healable PVA electrolyte. The self-healable all-in-one supercapacitor exhibits specific capacitance 470 mF cm− 2 at current density of 0.2 mA cm− 2 and energy density 32 µWh cm− 2 at power density 100 µW cm− 2. The broken device can be repaired itself and there is a 63% capacitance retention for the healable supercapacitor. This self-healing supercapacitor will promote the development of self-healing energy storage devices in wearable electronics.