Atik Jaschar, Diddens Diddo, Thienenkamp Johannes Helmut, Brunklaus Gunther, Winter Martin, Paillard Elie
Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149, Münster, Germany.
MEET Battery Research Center, University of Münster, Corrensstr. 46, 48149, Münster, Germany.
Angew Chem Int Ed Engl. 2021 May 17;60(21):11919-11927. doi: 10.1002/anie.202016716. Epub 2021 May 4.
N-alkyl-N-alkyl pyrrolidinium-based ionic liquids (ILs) are promising candidates as non-flammable plasticizers for lowering the operation temperature of poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs), but they present limitations in terms of lithium-ion transport, such as a much lower lithium transference number. Thus, a pyrrolidinium cation was prepared with an oligo(ethylene oxide) substituent with seven repeating units. We show, by a combination of experimental characterizations and simulations, that the cation's solvating properties allow faster lithium-ion transport than alkyl-substituted analogues when incorporated in SPEs. This proceeds not only by accelerating the conduction modes of PEO, but also by enabling new conduction modes linked to the solvation of lithium by a single IL cation. This, combined with favorable interfacial properties versus lithium metal, leads to significantly improved performance on lithium-metal polymer batteries.
基于N-烷基-N-烷基吡咯烷鎓的离子液体（ILs）作为降低聚环氧乙烷（PEO）基固体聚合物电解质（SPEs）工作温度的不可燃增塑剂具有很大潜力，但它们在锂离子传输方面存在局限性，比如锂离子迁移数低得多。因此，制备了一种带有七个重复单元的低聚环氧乙烷取代基的吡咯烷鎓阳离子。我们通过实验表征和模拟相结合的方法表明，当该阳离子掺入SPEs中时，其溶剂化性质使锂离子传输比烷基取代的类似物更快。这不仅通过加速PEO的传导模式来实现，还通过使单个IL阳离子与锂的溶剂化相关的新传导模式成为可能。这与对锂金属有利的界面性质相结合，显著提高了锂金属聚合物电池的性能。
