Download all files (5.54MB)

コレクション

引用

説明:

Conventional aqueous and organic electrolytes often suffer from toxicity, flammability, poor performance at low temperatures, or limited electrochemical stability, motivating the search for environmentally-friendly alternatives. Herein, we report a comprehensive study on aqueous choline – phosphate electrolytes based on choline dihydrogen phosphate (CDHP) and mixed choline dihydrogen phosphate and choline hydrogen phosphate (CDHP + CHP) systems as green electrolytes for low-temperature energy storage devices. Both salts were synthesized via neutralization of choline hydroxide with phosphoric acid. Physicochemical analysis revealed that pure CDHP solutions exhibit acidic pH, which limits the electrochemical stability window (ESW) due to hydrogen evolution. However, the introduction of CHP effectively tunes the electrolyte pH towards near-neutral values, while simultaneously enhancing ionic conductivity. The mixed CDHP + CHP electrolyte achieved improved ESW, maintaining high conductivity across a concentration range from 1 to 5 mol ⋅ kg−1 and down to − 20°C. Electrochemical investigations on carbon/carbon symmetric capacitors using these electrolytes reveal electric double-layer (EDL) performance without redox activity in the low voltage range. However, mixed redox processes and EDL charging were observed at higher voltage, which have been evaluated with temperature-dependent electrochemical impedance spectroscopy. By modeling the Nyquist plot, absolute ion diffusion coefficients and desolvation rates have been calculated, which support the analysis of the Arrhenius plots showing that the mixed electrolyte lowers the bulk ion diffusion energy barrier for pure CDHP, driving its superior sub-zero performance.

権利情報:

• Creative Commons BY Attribution 4.0 International
  

キーワード: Choline phosphate, Anti-freezing electrolyte, carbon electrode, electric double-layer, Supercapacitor

刊行年月日: 2026-06-19

出版者: Taylor & Francis

掲載誌:

• Science and Technology of Advanced Materials (ISSN: 14686996) vol. 27 2688749

研究助成金:

原稿種別: 著者最終稿 (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.6364

公開URL: https://doi.org/10.1080/14686996.2026.2688749

関連資料:

その他の識別子:

連絡先:

更新時刻: 2026-06-24 11:55:20 +0900

MDRでの公開時刻: 2026-06-24 14:27:51 +0900