Water-in-Salt Battery Electrolyte for High-Voltage Supercapacitors: A Fundamental Study on Biomass and Carbon Fiber Electrodes

In this study, we investigated the use of a water-in-salt electrolyte (WiSE) for enhancing the performance of carbon-based supercapacitor electrodes. The all-biomass electrode and a peroxyacetyl nitrate-derived porous carbon fiber electrode (PPCF) were chosen as two examples for evaluating their electrochemical performance. WiSE provides a stable wide voltage window of 3 V, effectively inhibits undesirable water-splitting reactions. The presence of pseudocapacitance behavior, as evidenced by cyclic voltammetry scans, contributed to higher charge storage capacity. As a result, a high areal energy density and power density of 2.2 mWh cm(-2) and 11.7 mW cm(-2) were achieved for the all-biomass electrode, and a high areal energy density and power density of 0.4 mWh cm(-2) and 12.1 mW cm(-2) were achieved for the PPCF electrode. Overall, when coupled with carbon-based electrodes WiSE shows great promise for high-voltage supercapacitor applications, providing a balance between charge storage kinetics and interface stability. (c) 2024 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited. All rights, including fortext and data mining, AI training, and similar technologies, are reserved.