Ionic Liquids

The synthesis and physicochemical and electrochemical characterization of ionic liquids is an important field of research for the working group. The focus is on various types of energy storage devices as areas of application.

Examples for acetate based ionic liquids. Reprinted under permission of CC BY-NC Lizenz von Zheng et al. 2025, ChemElectroChem.

Picture: Zhong Zheng

Ionic liquids (ILs) are molten salts with a melting point below 100 ° C. They are generally composed of bulky, asymmetric organic cations paired with weakly coordinating inorganic or organic anions. They exhibit a unique combination of physicochemical properties, including negligible vapor pressure, high thermal and electrochemical stability, non-flammability, and wide electrochemical windows (often reaching 5–6 V).

Ionic liquids (ILs) have attracted significant attention as electrolytes for energy storage devices. This interest stems from the ability to fine-tune their chemical and physical properties through deliberate selection and molecular design of both cations and anions. Currently, our group is dedicated to developing novel ionic liquids with tailored structural and functional properties for advanced energy storage applications. We synthesize and conduct detailed physicochemical characterization of these ILs—assessing viscosity, density, ionic conductivity, thermal stability, and electrochemical stability windows—to determine their suitability as electrolytes. Their performance is evaluated in electrical double-layer capacitors (EDLCs) and hybrid supercapacitors, where they enable cost-efficiency, high-voltage operation, improved safety, and long-term capacitance stability. By integrating synthesis, characterization, and device testing, we aim to establish clear structure-property-performance relationships to advance IL-based electrolytes for safer, more efficient, and longer-lasting electrochemical capacitors

 

  • Publications

    Zheng, Z., Liu, S., & Balducci, A.; Protic and Aprotic Acetate-Based Ionic Liquids as Electrolytes for Electrical Double Layer Capacitors. ChemElectroChem 2025, 12 (7), e202400591.

    Stettner, T., Balducci, A.; Protic ionic liquids in energy storage devices: Past, present and future perspective. Energy Storage Materials 2021, 40, 402-414.

    Béguin, F., Presser, V., Balducci, A., & Frackowiak, E.; Carbons and electrolytes for advanced supercapacitors. Advanced Materials 2014, 26 (14), 2219-2251.

Related Projects

  • NI-CONSTRUCT project logo
    Picture: NI-Construct Consortium
    NI-CONSTRUCT (DFG 23-1)

    The Project focuses on the development of heterogeneous N2 conversion reactions for delocalized and sustainable N 2 conversion pathways.
    Project Duration: 1/2022-1/2027

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Investigators

  1. Demarthe, Nicolas, Dr Postdoc, Project: DeKarbon Professorship of Applied Electrochemistry

    Room R 210
    Philosophenweg 7a
    07743 Jena

    Dr. Nicolas Demarthe
    Image: Desirée Leistenschneider
  2. Zheng, Zhong PhD Student, Project: NI-CONSTRUCT Professorship of Applied Electrochemistry

    Room R 126
    Lessingstraße 12-14
    07743 Jena

    Zhong Zheng
    Image: Anne Günther (University of Jena)