Highly concentrated aqueous binary solutions of acetate salts are promising systems for different electrochemical applications, for example, energy storage devices. The very high solubility of CH3COOK allows us to obtain water-in-salt electrolyte concentrations, thus reducing ion activity and extending the cathodic stability of an aqueous electrolyte. At the same time, the presence of Li+ or Na+ makes these solutions compatible with intercalation materials for the development of rechargeable alkaline-ion batteries. Although there is a growing interest in these systems, a fundamental understanding of their physicochemical properties is still lacking. Here, we report and discuss the physicochemical and electrochemical properties of a series of solutions based on 20 mol kg-1 CH3COOK with different concentrations of CH3COONa. The most concentrated solution, 20 mol kg-1 CH3COOK + 7 mol kg-1 CH3COONa, gives the best compromise between transport properties and electrochemical stability, displaying a conductivity of 21.2 mS cm-1 at 25 °C and a stability window of up to 3 V in “ideal” conditions, i.e., using a small surface area and highly electrocatalytic electrode in a flooded cell. Careful Raman spectroscopy analyses help to address the interaction network, the phase evolution with temperature, and the crystallization kinetics.

Khalid, S., Pianta, N., Bonizzoni, S., Ferrara, C., Lorenzi, R., Paleari, A., et al. (2023). Structure–Property Correlations in Aqueous Binary Na+/K+–CH3COO– Highly Concentrated Electrolytes. JOURNAL OF PHYSICAL CHEMISTRY. C, 127(20), 9823-9832 [10.1021/acs.jpcc.3c01017].

Structure–Property Correlations in Aqueous Binary Na+/K+–CH3COO– Highly Concentrated Electrolytes

Khalid, Shahid
Primo
;
Pianta, Nicolò
Secondo
;
Bonizzoni, Simone;Ferrara, Chiara;Lorenzi, Roberto;Paleari, Alberto;Mustarelli, Piercarlo
Penultimo
;
Ruffo, Riccardo
Ultimo
2023

Abstract

Highly concentrated aqueous binary solutions of acetate salts are promising systems for different electrochemical applications, for example, energy storage devices. The very high solubility of CH3COOK allows us to obtain water-in-salt electrolyte concentrations, thus reducing ion activity and extending the cathodic stability of an aqueous electrolyte. At the same time, the presence of Li+ or Na+ makes these solutions compatible with intercalation materials for the development of rechargeable alkaline-ion batteries. Although there is a growing interest in these systems, a fundamental understanding of their physicochemical properties is still lacking. Here, we report and discuss the physicochemical and electrochemical properties of a series of solutions based on 20 mol kg-1 CH3COOK with different concentrations of CH3COONa. The most concentrated solution, 20 mol kg-1 CH3COOK + 7 mol kg-1 CH3COONa, gives the best compromise between transport properties and electrochemical stability, displaying a conductivity of 21.2 mS cm-1 at 25 °C and a stability window of up to 3 V in “ideal” conditions, i.e., using a small surface area and highly electrocatalytic electrode in a flooded cell. Careful Raman spectroscopy analyses help to address the interaction network, the phase evolution with temperature, and the crystallization kinetics.
Articolo in rivista - Articolo scientifico
Water-in-salt electrolytes, raman, acetate salts, DSC, electrochemistry
English
13-mag-2023
2023
127
20
9823
9832
open
Khalid, S., Pianta, N., Bonizzoni, S., Ferrara, C., Lorenzi, R., Paleari, A., et al. (2023). Structure–Property Correlations in Aqueous Binary Na+/K+–CH3COO– Highly Concentrated Electrolytes. JOURNAL OF PHYSICAL CHEMISTRY. C, 127(20), 9823-9832 [10.1021/acs.jpcc.3c01017].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/416801
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