title: Capillary electrophoresis with contactless conductivity detection for the quantification of fluoride in lithium ion battery electrolytes and in ionic liquids-A comparison to the results gained with a fluoride ion-selective electrode.
abstract: In this study, an optimized method using capillary electrophoresis (CE) with a direct contactless conductivity detector (C4D) for a new application field is presented for the quantification of fluoride in common used lithium ion battery (LIB) electrolyte using LiPF6in organic carbonate solvents and in ionic liquids (ILs) after contacted to Li metal. The method development for finding the right buffer and the suitable CE conditions for the quantification of fluoride was investigated. The results of the concentration of fluoride in different LIB electrolyte samples were compared to the results from the ion-selective electrode (ISE). The relative standard deviations (RSDs) and recovery rates for fluoride were obtained with a very high accuracy in both methods. The results of the fluoride concentration in the LIB electrolytes were in very good agreement for both methods. In addition, the limit of detection (LOD) and limit of quantification (LOQ) values were determined for the CE method. The CE method has been applied also for the quantification of fluoride in ILs. In the fresh IL sample, the concentration of fluoride was under the LOD. Another sample of the IL mixed with Li metal has been investigated as well. It was possible to quantify the fluoride concentration in this sample.
authors: University of Muenster, MEET Battery Research Center, Institute of Physical Chemistry, Münster, Germany.
authors: Marcelina
authors: M
authors: Pyschik
authors: University of Muenster, MEET Battery Research Center, Institute of Physical Chemistry, Münster, Germany.
authors: Marcel
authors: M
authors: Klein-Hitpaß
authors: University of Muenster, MEET Battery Research Center, Institute of Physical Chemistry, Münster, Germany.
authors: Sabrina
authors: S
authors: Girod
authors: University of Muenster, MEET Battery Research Center, Institute of Physical Chemistry, Münster, Germany.|Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich, Münster, Germany.
authors: Martin
authors: M
authors: Winter
authors: University of Muenster, MEET Battery Research Center, Institute of Physical Chemistry, Münster, Germany.
authors: Sascha
authors: S
authors: Nowak
mesh_terms: D004553:Electric Conductivity; D011211:Electric Power Supplies; D004573:Electrolytes / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D005459:Fluorides / Q000032:analysis*; D017736:Ion-Selective Electrodes; D052578:Ionic Liquids / Q000737:chemistry*; D057230:Limit of Detection; D008094:Lithium; D015203:Reproducibility of Results
chemical_list: D004573:Electrolytes; D052578:Ionic Liquids; D008094:Lithium; D005459:Fluorides
keywords: Capillary electrophoresis; Contactless conductivity detector; Fluoride quantification; Ionic liquids; Lithium ion battery electrolytes