Porous Liquids as Electrolyte: A Case Study of Li+ and Mg2+ Ion Transport in Crown Ether-Based Type-II Porous Liquids

• Published in: ACS materials letters Vol. 5; no. 2; pp. 330 - 335
• Main Authors: Shin, Sun Hae Ra, Lim, Hyung-Seok, Han, Kee Sung, Robinson, Alexander J., Hollas, Aaron, Sivakumar, Bhuvaneswari M., Johnson, Samantha I., Chun, Jaehun, Wang, Wei, Murugesan, Vijayakumar, Thallapally, Praveen K.
• Format: Journal Article
• Language: English
• Published: American Chemical Society 06.02.2023
• ISSN: 2639-4979; 2639-4979
• DOI: 10.1021/acsmaterialslett.2c00956

We demonstrated an enhanced ion transport properties of type-II porous liquid-based electrolyte in which crown ether provides internal porosity and are capable of coordinating and transporting Li+ and Mg2+ ions. We investigated the solvation structure and transport properties of the porous liquid electrolytes with different functional groups and cavity sizes. Among the electrolytes studied, the 12-crown-4 (12C4)-based porous liquid electrolyte exhibited the most enhanced ionic conductivity due to size match between the crown ether cavity and the Li+ ion. Nuclear magnetic resonance and Fourier transform infrared analyses revealed that addition of crown ethers reduces the Li+ ion–solvent interaction, resulting in the formation of Li-crown ether complexes. Molecular simulations complement such observations by describing the detailed solvation environment at molecular scale, including complexation between Li+ and Mg2+ ions and 12C4. The strategy described here using crown ether-based porous liquids should be applicable to design versatile electrolytes for various metal-ion batteries.