Investigating Ca²⁺ salt–based polymer-in-salt electrolyte for future energy storage systems

The scientific community is continuously putting efforts to improve the energy/power density of energy storage devices, which leads to development of novel materials with enhanced electrochemical properties. Polymer-in-salt electrolytes (PISEs) are expected to have faster ion transport and hence may result in improved power density. In the present study, Ca salt–based PISE is synthesized using glutaraldehyde (GA)–crosslinked arrowroot starch as host matrix. The synthesized PISE has high conductivity (~ 0.01 S/cm), wide electrochemical stability window (ESW > 3 V), and small characteristic relaxation time (τ ~ 17 µs) indicating the possibility of faster response in any device fabricated using synthesized PISEs. Fabricated supercapacitor, using the highest conducting PISE with rGO as electrode, has specific capacitance ~ 17 F/g at 1 mV/s and high power density 2.1 kW/kg with coulombic efficiency (CE) of > 90.05% and with CAC as electrode, specific capacitance ~ 125 F/g at 1 mV/s and high power density 2.1 kW/kg with coulombic efficiency (CE) of > 99%.