High strength and toughness poly (vinyl alcohol)/gelatin double network hydrogel fabricated via Hofmeister effect for polymer electrolyte

In this study, a versatile poly (vinyl alcohol)/gelatin hydrogel electrolyte (PGN) with excellent mechanical properties and electrochemical performance is prepared via a simple and green route based on double network strategy. Herein, Na 2 SO 4 introduced into double network by soaking strategy can be used as the role of ionic donator and Hofmesiter series. PGN gels have exhibited a porous 3D network structure and based on the fabrication strategy of freeze–thaw and Hofmeister effect, there are not any irreversible chemical cross-linked in the gel. As a result, the PGN gel has outstanding tensile strength (1.0 Mpa), stability (582 %) and toughness (3.2 MJ m −3 ). Especially, the assembled supercapacitor of rGO gel as electrodes and PGN gel as electrolyte shows ideal electrochemistry performance (specific capacitance, 83.6 F g −1 at 1 A/g). This study is desirable for application in supercapacitor devices using natural polymer via a simple and green method.