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, Na2SO4 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.