Fabrication of poly(vinyl alcohol)-graphene oxide-polypyrrole composite hydrogel for elastic supercapacitors

High-performance elastic supercapacitors represent a promising kind of energy storage devices that can be employed in soft robotics and wearable electronics. The development of novel functional materials as supercapacitor electrode is still tremendously challenging. In the present work, the conductive polyvinyl alcohol-graphene oxide-polypyrrole (PVA-GO-PPy) composite hydrogels are fabricated through in situ polymerization of pyrrole in the presence of PVA and GO and subsequent freeze-thawing. Owing to the unique porous layered-wrinkle network and functional component of PVA-GO-PPy composite hydrogels, the as-prepared hydrogels exhibit lightweight, elasticity, compressibility, formability and softness. Furthermore, the mechanically robust and microstructured PVA-GO-PPy composite hydrogels are used to construct an elastic symmetric solid-state supercapacitor with good electrochemical performance. The device exhibits long-term compression/recovery elasticity under 50% strain, and even the volumetric capacitance retention is still about 81% when the strain is up to 80%. The excellent compression/recovery elasticity and good mechanical integrity of the high-performance supercapacitor based on PVA-GO-PPy composite hydrogel open up new opportunities for next-generation electronic devices in the practical application.