Broadband Terahertz Conductivity of Solid-state Polymer Electrolytes

Dr. Hassan Hafez1, Ms. Johanna Weidelt1, Dr. Jijeesh Nair2, Dr. Diddo Diddens2, Dr. Wentao Zhang1, Mr. Felix Pfeiffer2, Mr. Tiago de Oliveira Schneider3, Prof. Markus Meinert3, Dr. Tomoki Hiraoka1, Ms. Linda Nesterov1, Dr. Masoud Baghernejad2, Prof. Dmitry Turchinovich1
1Bielefeld University, Bielefeld, Germany. 2Helmholtz-Institute Münster, Münster, Germany. 3Technical University of Darmstadt, Darmstadt, Germany


The polyethylene oxide (PEO)-based polymer electrolytes containing lithium salts pave the way for the development of safe lithium batteries with high energy storage capacity. Enabled by the flexibly vibrating polymer matrix, the Li-ion transport occurs via hopping along and between the polymer chains. Here, terahertz (THz) time-domain spectroscopy over a frequency range extending from 0.1 THz to 7 THz is applied to investigate the conduction properties of PEO-based electrolytes with lithium salts, and to elucidate the associated dependence of the THz conductivity on the content of the added lithium salt and the electrolyte temperature.