title: Determining the mobility of ions by transient current measurements at high voltages.
abstract: We present polarization and transient current experiments that allow an independent determination of the charge carrier density and the mobility of ions in polymer electrolytes at low charge carrier density. The method relies on a complete depletion of ions in the bulk electrolyte achieved by applying high voltages. Based on a qualitative model for the charge dynamics in this nonlinear regime, the method is exemplarily applied to a system of polymethylmethacrylate doped with small amounts of a lithium salt. The independently obtained values for the ionic mobility, the charge carrier density, and the conductivity are consistent for all salt concentrations studied. Criteria for the applicability of the method are discussed.
authors.affiliation: Institute of Physics, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120, Halle, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Kohn
authors.forename: Klaus
authors.initials: K
authors.lastname: Schröter
authors.forename: Thomas
authors.initials: T
authors.lastname: Thurn-Albrecht
mesh_terms: D004553:Electric Conductivity; D004573:Electrolytes; D007477:Ions; D008094:Lithium; D011108:Polymers; D012965:Sodium Chloride
chemical_list: D004573:Electrolytes; D007477:Ions; D011108:Polymers; D012965:Sodium Chloride; D008094:Lithium