Kinsey Thomas, Glynn Kaitlin, Cosby Tyler, Iacob Ciprian, Sangoro Joshua
The Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37916, United States.
Department of Chemistry, US Naval Academy, Annapolis, Maryland 21402, United States.
ACS Appl Mater Interfaces. 2020 Sep 30;12(39):44325-44334. doi: 10.1021/acsami.0c12381. Epub 2020 Sep 16.
Polymerized ionic liquids are a promising class of versatile solid-state electrolytes for applications ranging from electrochemical energy storage to flexible smart materials that remain limited by their relatively low ionic conductivities compared to conventional electrolytes. Here, we show that the polymerization of the vinyl cationic monomer, 1-ethyl-3-vinylimidazolium with the bis(trifluoromethanesulfonyl)imide counteranion, under nanoconfinement within 7.5 ± 1.0 nm diameter nanopores results in a nearly 1000-fold enhancement in the ionic conductivity compared to the material polymerized in bulk. Using insights from broadband dielectric and Raman spectroscopic techniques, we attribute these results to the role of confinement on molecular conformations, ion coordination, and subsequently the ionic conductivity in the polymerized ionic liquid. These results contribute to the understanding of the dynamics of nanoconfined molecules and show that polymerization under nanoscale geometric confinement is a promising path toward enhancing ion conductivity in polymer electrolytes.
聚合离子液体是一类很有前景的多功能固态电解质，可用于从电化学储能到柔性智能材料等各种应用，但与传统电解质相比，其相对较低的离子电导率仍然限制了它们的应用。在此，我们表明，在直径为7.5±1.0纳米的纳米孔内进行纳米限域时，乙烯基阳离子单体1-乙基-3-乙烯基咪唑鎓与双（三氟甲磺酰）亚胺抗衡阴离子的聚合，与本体聚合的材料相比，离子电导率提高了近1000倍。利用宽带介电和拉曼光谱技术的见解，我们将这些结果归因于限域对分子构象、离子配位以及随后对聚合离子液体中离子电导率的作用。这些结果有助于理解纳米限域分子的动力学，并表明在纳米尺度几何限域下进行聚合是提高聚合物电解质中离子电导率的一条有前景的途径。
