Electrolyte-Dependent Electrochemical Performance of a Lead-Free Semiconducting Co(II)-Halide Hybrid for Aqueous Supercapacitors
7 affiliations
- 1Faculty of Sciences of Sfax
- 2University of Sfax
- 3Department of Chemical Engineering, Engineering Faculty
- 4Sivas Cumhuriyet University
- 5Department of Inorganic Chemistry, Faculty of Chemical Technology
- 6University of Chemistry and Technology Prague
- 7Bordeaux INP, ICMCB, UMR 5026, Pessac, France, F-33600
Abstract
Developing affordable and stable electrode materials is crucial for advancing sustainable supercapacitor technologies. In this study, a lead-free Co(II)-halide hybrid material (CoTEA) was synthesized via slow evaporation and evaluated as an electrode for aqueous electrochemical energy storage. Single-crystal X-ray diffraction showed a zero-dimensional structure consisting of isolated tetrahedral units separated by tetraethylammonium cations. Morphological and spectroscopic analyses confirmed the crystalline nature and the Co(II) oxidation state of the material. Optical measurements indicated semiconducting behavior with a band gap of 3.64 eV. The electrochemical response of CoTEA was highly dependent on the electrolyte used. At 5 mV s-1, specific capacitances of 5.01, 22.24, and 21.37 F g-1 were recorded in 1 M H2SO4, 0.5 M Na2SO4, and 6 M KOH, respectively. While Na2SO4 yielded the highest capacitance at the lowest scan rate, KOH demonstrated better rate performance and lower charge-transfer resistance, suggesting more efficient interfacial kinetics. In 6 M KOH, CoTEA achieved a GCD-specific capacitance of 21.41 F g-1 at 0.5 A g-1 and maintained about 85% of its initial capacitance after 3000 cycles. These results underscore the significant impact of electrolyte composition on the charge-storage behavior of CoTEA and present it as a promising, tunable material for aqueous supercapacitor applications.strong influence of electrolyte composition on the charge-storage behavior of CoTEA and highlight it as a promising tunable material for aqueous supercapacitor applications.
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BibTeX
@misc{abid2026electrolytedependent,
title = {{Electrolyte-Dependent Electrochemical Performance of a Lead-Free Semiconducting Co(II)-Halide Hybrid for Aqueous Supercapacitors}},
author = {Dhouha Abid and Emna Ben Messaoud and Ayten Ateş and Sana Akir and Philippe Guionneau and Stanislav Pechev and Nathalie Daro and Zakaria Elaoud},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15008470/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008470/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Electrolyte-Dependent Electrochemical Performance of a Lead-Free Semiconducting Co(II)-Halide Hybrid for Aqueous Supercapacitors
AU - Dhouha Abid
AU - Emna Ben Messaoud
AU - Ayten Ateş
AU - Sana Akir
AU - Philippe Guionneau
AU - Stanislav Pechev
AU - Nathalie Daro
AU - Zakaria Elaoud
PY - 2026
DA - 2026/09/08
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008470/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008470/v1
AB - Developing affordable and stable electrode materials is crucial for advancing sustainable supercapacitor technologies. In this study, a lead-free Co(II)-halide hybrid material (CoTEA) was synthesized via slow evaporation and evaluated as an electrode for aqueous electrochemical energy storage. Single-crystal X-ray diffraction showed a zero-dimensional structure consisting of isolated tetrahedral units separated by tetraethylammonium cations. Morphological and spectroscopic analyses confirmed the crystalline nature and the Co(II) oxidation state of the material. Optical measurements indicated semiconducting behavior with a band gap of 3.64 eV. The electrochemical response of CoTEA was highly dependent on the electrolyte used. At 5 mV s-1, specific capacitances of 5.01, 22.24, and 21.37 F g-1 were recorded in 1 M H2SO4, 0.5 M Na2SO4, and 6 M KOH, respectively. While Na2SO4 yielded the highest capacitance at the lowest scan rate, KOH demonstrated better rate performance and lower charge-transfer resistance, suggesting more efficient interfacial kinetics. In 6 M KOH, CoTEA achieved a GCD-specific capacitance of 21.41 F g-1 at 0.5 A g-1 and maintained about 85% of its initial capacitance after 3000 cycles. These results underscore the significant impact of electrolyte composition on the charge-storage behavior of CoTEA and present it as a promising, tunable material for aqueous supercapacitor applications.strong influence of electrolyte composition on the charge-storage behavior of CoTEA and highlight it as a promising tunable material for aqueous supercapacitor applications.
ER -