Ionic Liquid-Based Electrolyte Membranes for Medium-High Temperature Lithium Polymer Batteries

Guk-Tae Kim; Stefano Passerini; Maria Carewska; Giovanni Battista Appetecchi

doi:10.3390/membranes8030041

Ionic Liquid-Based Electrolyte Membranes for Medium-High Temperature Lithium Polymer Batteries

Membranes (Basel). 2018 Jul 10;8(3):41. doi: 10.3390/membranes8030041.

Authors

Guk-Tae Kim^{1

2}, Stefano Passerini^{3

4}, Maria Carewska⁵, Giovanni Battista Appetecchi⁶

Affiliations

¹ Helmholtz Institute Ulm-Karlsruhe Institute of Technology, Helmholtzstrasse 11, 89081 Ulm, Germany. guk-tae.kim@kit.edu.
² Karlsruher Institute of Technology (KIT), P.O. Box 3640, 76021 Eggenstein-Leopoldshafen, Germany. guk-tae.kim@kit.edu.
³ Helmholtz Institute Ulm-Karlsruhe Institute of Technology, Helmholtzstrasse 11, 89081 Ulm, Germany. stefano.passerini@kit.edu.
⁴ Karlsruher Institute of Technology (KIT), P.O. Box 3640, 76021 Eggenstein-Leopoldshafen, Germany. stefano.passerini@kit.edu.
⁵ ENEA, Agency for New Technologies, Energy and Sustainable Economic Development, DTE-PCU-SPCT, Via Anguillarese 301, 00123 Rome, Italy. maria.carewska@enea.it.
⁶ ENEA, Agency for New Technologies, Energy and Sustainable Economic Development, SSPT-PROMAS-MATPRO, Via Anguillarese 301, 00123 Rome, Italy. gianni.appetecchi@enea.it.

Abstract

Li⁺-conducting polyethylene oxide-based membranes incorporating N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide are used as electrolyte separators for all-solid-state lithium polymer batteries operating at medium-high temperatures. The incorporation of the ionic liquid remarkably improves the thermal, ion-transport and interfacial properties of the polymer electrolyte, which, in combination with the wide electrochemical stability even at medium-high temperatures, allows high current rates without any appreciable lithium anode degradation. Battery tests carried out at 80 °C have shown excellent cycling performance and capacity retention, even at high rates, which are never tackled by ionic liquid-free polymer electrolytes. No dendrite growth onto the lithium metal anode was observed.

Keywords: N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide; ionic liquids; lithium polymer batteries; poly(ethyleneoxide); polymer electrolytes.