An asymmetric MnO2|activated carbon supercapacitor with highly soluble choline nitrate-based aqueous electrolyte for sub-zero temperatures
Schrade S. Zhao Z. Supiyeva Z. Chen X. Dsoke S. Abbas Q.
1 September 2022Elsevier Ltd
Electrochimica Acta
2022#425
MnO2|activated carbon supercapacitors are attractive power devices that rival the electric double-layer capacitors (EDLCs) due to high reachable voltage. However, they greatly suffer from performance loss at low temperature as most of aqueous electrolytes freeze below ca. -10°C. Here, a concentrated choline nitrate-based (5 mol/L aqueous ChNO3) electrolyte is applied to extend the working temperature range due to its eutectic-like properties. In such electrolyte, water acts as hydrogen bond donor for nitrate anion and low hydration energy for large choline cations favors ionic transport. The MnO2/CNT composite electrode with a hierarchical structure has been synthesized by hydrothermal process. The presence of CNTs as core component facilitates the electron conduction, while the two-dimensional MnO2 flakes grown on the surface provide electrolyte transport pathways and improve the interfacial processes (pseudocapacitive charge/discharge). Thanks to the low hydration of choline cation, the individual activated carbon (AC, negative) and MnO2/CNT (positive) electrodes are charged symmetrically up to a cell voltage of 1.8 V. Overall, due to the wide electrochemical stability window (∼2.0 V) and anti-freezing properties of ChNO3-based aqueous electrolyte and the hierarchical design of the MnO2/CNT composite, the asymmetric supercapacitor operates down to -40 °C and displays excellent energy and coulombic efficiency with no loss of performance after several thousand cycles. This work provides a new possibility on the low temperature application of high voltage supercapacitors.
Choline nitrate , CNTs , Low temperature , MnO2 , Pseudocapacitance , Supercapacitor
Text of the article Перейти на текст статьи
Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, D-76344, Germany
Tianjin Key Laboratory of Brine Chemical Engineering and Ecological Utilization of Resources, Tianjin Engineering Center of Marine Chemical Engineering & Technology, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
Al-Farabi Kazakh National University, 71 al-Farabi Ave., Almaty, 050040, Kazakhstan
Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Institute of Semiconductors, South China Normal University, Guangzhou, 510631, China
Faculty of Chemical Technology, Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology (PUT), Poznan, 60965, Poland
Institute for Chemistry and Technology of Materials, Graz University of Technology (TU Graz), Stremayrgasse 9, Graz, 8010, Austria
Institute for Applied Materials (IAM)
Tianjin Key Laboratory of Brine Chemical Engineering and Ecological Utilization of Resources
Al-Farabi Kazakh National University
Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials
Faculty of Chemical Technology
Institute for Chemistry and Technology of Materials
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026