Recent advancements and perspectives in conductive hydrogel-based flexible all-in-one supercapacitors

Abstract

Flexible supercapacitors (FSCs) have been widely studied due to their advantages such as high power density, long cycle life, high safety, and excellent mechanical properties. Compared with the traditional "sandwich" structure FSCs, flexible all-in-one supercapacitors (FASCs) exhibit lower interface resistance and enhanced deformation resistance, making them more suitable for flexible wearable electronics. Conductive hydrogels (CHs), which combine high electrical conductivity with robust mechanical properties, show unique potential in supercapacitor (SC) applications. However, a comprehensive review of CH applications in FASCs remains lacking. This review summarizes recent preparation methods and multifunctional properties of typical CH-based FASCs. First, the fundamental concepts and preparation strategies of FASCs are introduced. Subsequently, their functional characteristics-including electrochemical performance, deformation tolerance, self-healing capability, wide-temperature adaptability, and biodegradability-are systematically discussed. Furthermore, applications of FASCs in wearable electronic devices are explored. Finally, challenges and future research directions for CH-based FASCs are outlined.