Highly self-adhesive, compressible, stretchable, all hydrogel-based supercapacitor for wearable/portable electronics

The increasing popularity of portable/wearable multifunctional electronic devices has highlighted the need for multifunctional power-supply devices. To fulfill this need, we firstly designed a highly self-adhesive and deformable polyacrylamide-based hydrogel electrode. Inspiration by mussels, nanofillers with the design of confined nanospace that formed by the composite of polydopamine-reduced graphene oxide and a compound of cobalt-nickel bimetal oxide and cobalt nitride was involved in the as-prepared hydrogel electrode. This design endows the as-prepared electrode with both the impressive self-adhesive property as well as electrochemical performance. Secondly, a multifunctional all hydrogel-based supercapacitor was assembled by the same as-prepared polyacrylamide hydrogel matrix of electrodes and an electrolyte. The self-adhesive property of both electrode and electrolyte provides a tightly connected interface to ensure structural stability and results in a highly electrical stability during different deformations. Moreover, this multifunctional all hydrogel-based supercapacitor can adhere to the tissue and be used as a functional electronic component as both energy storage and power-supply device. This designed multifunctional supercapacitors can provide insights for further strategies to address energy storage alternatives for portable/wearable electronics.