Sustainable glycerol carbonate electrolytes for Li-ion supercapacitors: performance evaluation of butyl, benzyl, and ethyl glycerol carbonates

Abstract

Substitution of flammable, toxic solvents in electrolytes with alternative green options is of significant commercial and environmental interest. Here, we report the synthesis and physicochemical properties of glycerol carbonate (GlyC) based solvents as electrochemically stable electrolytes for lithium ion supercapacitors. Glycerol carbonates with pendent butyl, benzyl, and ethyl side chains are all thermally stable and exhibit compositional dependent properties. Of the three glycerol-based electrolytes, the butyl and ethyl GlyC analogs exhibit the highest conductivity and discharge capacitance at room and elevated temperatures. The new electrolytes allow for safe operation of a Li-ion supercapacitor at room temperature and 100 °C, with specific capacitances between 115 and 162 F g⁻¹, and good electrochemical performance at 100 °C.