Aggarwal K.Yadav D.Tiwari K.Kushwaha P.Srivastava N.2025-01-132025-01-1320249477047https://dl.bhu.ac.in/ir/handle/123456789/1106The 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 (? ~ 17��s) 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%. � The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.enActivated carbonArrowroot starchCalciumPolymer-in-salt electrolytesRGOSupercapacitorArticle10.1007/s11581-024-05754-4