LAUSR

Flexible energy‐storage devices lay the foundation for a convenient, advanced, fossil fuel‐free society. However, the fabrication of flexible energy‐storage devices remains a tremendous challenge due to the intrinsic dissimilarities between electrode and electrolyte. In this study, a strategy is proposed for fabricating a flexible electrode and electrolyte entirely inside a matrix. First, a nest‐structural and redox‐active ionohydrogel with excellent stretchability (up to 3000%) and conductivity (167.9 mS cm−1) is designed using a hydrated ionic liquid (HIL) solvent and chemical foaming strategy. The nest‐structure ionohydrogel provides sufficient “highways” and “service area”, and the cation in HIL facilitates the reaction, transportation, and deposition of benzoquinone. Subsequently, in situ, a novel benzoquinone crystal–gel interface (CGI) is in situ fabricated on the surface of the ionohydrogel through electrochemical deposition of benzoquinone. Thus, an integrated CGI‐gel platform is successfully achieved with a middle body as an electrolyte and the surficial redox‐active CGI membrane for electrochemical energy conversion and storage. Based on the CGI‐gel platform, an extreme simple and effective “stick‐to‐use” strategy is proposed for constructing flexible energy‐storage devices and then a series of flexible supercapatteries are fabricated with high stretchability and capacitance (5222.1 mF cm−2 at 600% strain), low self‐discharge and interfacial resistance and a wearable, self‐power and intelligent display.