Stretchable, self-adhesion and durable polyacrylamide/polyvinylalcohol dual-network hydrogel for flexible supercapacitor and wearable sensor

Abstract

Conductive hydrogels show great promise in the field of flexible electronics, but traditional hydrogels have some problems such as poor environmental tolerance, being easy to damage and not being durable. In this work, polyacrylamide (PAM) was used as the main network, and polyvinylalcohol (PVA) was added to construct a dual network hydrogel. Simultaneously, LiTFSI was added to improve hydrogel ionic conductivity, and multiple interionic and intermolecular interactions formed within the gel, significantly improving the gel's mechanical properties and durability. The area specific capacitance of the hydrogel-based supercapacitor is 383.4 mF cm−2, and it still maintains a high cycle life of 90.35 % after 10,000 cycles. The hydrogel-based strain sensor shows fatigue resistance, rapid recovery after 400 stretches, high sensitivity (GF = 3.83 at 300–400 %), and the ability to detect human motion. Therefore, the multi-functional properties of PAM/PVA/LiTFSI hydrogels are expected to play a demonstration role in a new generation of flexible electronic products.