Ionically conducting and environmentally safe gum Arabic as a high-performance gel-like electrolyte for solid-state supercapacitors

Abstract

The development of innovative gel electrolyte is nowadays considered one of the most important features for the realization of high-safety and high-performance energy storage devices. Consequently, in the past few years, much effort have been dedicated to prepare new gel polymer electrolytes, unfortunately, they suffer from poor wettability with electrode surface which retard them to achieve high ion accessibility. Here, we propose a novel gel-like electrolyte which is prepared by exploiting the emulsifying property of low cost and environmentally safe gum Arabic (GA) as the polymer matrix and ortho-phosphoric acid (H3PO4) as the supporting electrolyte. This prepared gel electrolyte (GA/H3PO4) demonstrates excellent supercapacitive performance in the counterpart of conventional gel electrolyte of polyvinyl alcohol (PVA)/H3PO4 in all-solid-state supercapacitor. Besides the electrolytic performance, as prepared gel also exhibited the self-healing feature, no decay in capacitance was observed upon mechanically separation and restacking of both electrodes of the solid-state assembly. The prepared GA/H3PO4 electrolyte is also capable of maintaining its capacitance over 5000 repeating charge/discharge cycles.