Performance enhancement of gel polymer electrolytes using sulfonated poly(ether ether ketone) for supercapacitors

Gel polymer electrolytes (GPEs) with reasonable mechanical properties are highly favorable for flexible/stretchable solid-state supercapacitors. However, the widely explored poly(acrylic acid) (PAA)-based GPEs provide unsatisfactory mechanical performance. Herein, a useful strategy is adopted to improve the performance of PAA-based GPEs by incorporating sulfonated poly(ether ether ketone) (SPEEK) chains. The optimum SPEEK-enhanced PAA GPE shows an ionic conductivity of 100 +/- 1.57 mS cm(-1), ultimate tensile strength of 4.2 +/- 0.24 kPa and elongation at break of 858%, which are larger than those of the plain PAA GPE. A supercapacitor developed using such a SPEEK-enhanced GPE also delivers higher specific capacitance, larger energy density and comparable cycling stability compared to a supercapacitor using a PAA GPE. This work suggests that rigid ionic polymers are suitable for improving the performance of GPEs with inferior mechanical properties. (c) 2021 Society of Chemical Industry

Automated summary

In this study, the performance of PAA-based GPEs was improved by incorporating SPEEK chains, resulting in enhanced ionic conductivity and mechanical properties. The supercapacitor developed using the SPEEK-enhanced GPE showed higher specific capacitance and energy density compared to the one using plain PAA GPE.