Measurement of Ionic and Electronic Conductivities of Conductive Polymers in Battery Electrolyte to Guide Binder Development

Abstract

Conductive polymers are being studied increasingly as additives into lithium battery electrodes, supercapacitors and other electrochemical devices due to their ability to conduct electrons and ions and serve as binders.1 Accurately measuring the large changes of ionic and electronic conductivities in a relevant electrolyte as a function of electrochemical doping has been a challenge thus far. We have developed a methodology for such measurements that combines the use of impedance spectroscopy on interdigitated electrodes conducted in two separate electrode geometries.2 We demonstrate the wide applicability of this methodology for the measurement of conductivity of p-type and n-type conducting polymer thin films as a function of electrochemical doping in relevant battery electrolytes. Such measurements have aided the screening and selection of various p-doped polymers for lithium ion battery cathodes as well as n-doped polymers for lithium-ion battery anodes and sulfur cathodes.3 References J. Lopez, D. G. Mackanic, Y. Cui, and Z. Bao, Nat. Rev. Mater., 4, 312 (2019). B. Zayat, P. Das, B. C. Thompson, and S. R. Narayan, J. Phys. Chem. C, 125, 7533 (2021). P. Das, B. Zayat, Q. Wei, C. Z. Salamat, I.-B. Magdău, R. Elizalde-Segovia, D. Rawlings, D. Lee, G. Pace, A. Irshad, L. Ye, A. Schmitt, R. A. Segalman, T. F. Miller, S. H. Tolbert, B. S. Dunn, S. R. Narayan, and B. C. Thompson, Chem. Mater., 32, 9176 (2020).