Dual cation Kgu/PAM Gel polymer electrolyte with high ionic conductivity and mechanical strength for flexible All-Solid-State supercapacitors

Abstract

Gel polymer electrolytes (GPEs) have attracted much attention due to their excellent flexibility, good interface contact, and high safety in solid-state supercapacitors (SSCs). However, in practical applications, GPEs still face low ionic conductivity and poor mechanical strength. This study delineates a novel dual-cationic Kgu/PAM GPE, the ion diffusion coefficients in which are 1.51 × 10-8 cm2 s−1 (K+) and 4.77 × 10-9 cm2 s−1 (Na+), respectively. Radial distribution function and in-situ Fourier transform infrared spectroscopy have confirmed that the migration mechanism of dual-cations in Kgu/PAM is through the long-range hydration channels, which is depended on the continuous formation of binding water facilitated by movement of Kgu and PAM chain segments. When assembled dual-cationic Kgu/PAM GPE to a flexible solid-state asymmetric supercapacitor, it delivers a high ionic conductivity (86.9 mS cm−1), an excellent energy rate density (86.1 Wh kg−1) and outstanding power density (476 W kg−1). In addition, dual-cationic Kgu/PAM GPE exhibits an excellent strain threshold of 910 % and remarkable mechanical strength of 35 KPa, good flexibility and flame retardant, highlighting the potential for its practical application in various fields. Collectively, these findings herald a novel paradigm in the development of secure and efficacious flexible wearables.