Designing Pyrrolidinium-Based Ionic Liquid Electrolytes for Energy Storage: Thermal and Electrical Behaviour of Ternary Mixtures with Lithium Salt and Carbonates
Year: 2025
Type: article
Abstract: Ionic liquids (ILs) have attracted increasing attention due to their unique physicochemical properties. Among them, 1-Methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, emerges as an ideal candidate for fundamental studies in electrochemical applications. This work aims to deepen the understanding of its conductivity performance, and potential interaction with added metal salts, providing insight into its applicability in advanced energy storage systems. Firstly, binary mixtures with ethylene carbonate have been prepared to improve the transport properties and select the optimal concentration of both components. Subsequently, lithium salt was added to design the adequate electrolyte. The thermal and electrochemical characterisation of these mixtures was performed by differential scanning calorimetry (DSC) thermogravimetric analysis (TGA) and Broad Band Dielectric Spectroscopy (BBDS). The results reveal a wide liquid range for the ternary systems studied, extending below −80 °C and above 120 °C. Additionally, they exhibit notably high conductivity values at room temperature (ranging from 0.2 S·m−1 for the most concentrated to 0.70 S·m−1 for the lowest concentrated), which highlights their suitability for advanced electrochemical applications, including but not limited to batteries. This extended liquid phase mitigates, or potentially eliminates, some of the most common issues associated with current electrolytes, such as undesired crystallisation at low temperatures. In this paper, a new promising electrolyte, consisting of a ternary mixture obtained by adding lithium salt to the eutectic composition of [C3C1Pyrr][TFSI] and ethyl carbonate is proposed.
Source: Applied Sciences
DOI: 10.3390/app15084354
Institution: Universidade de Santiago de Compostela
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W4409457075