US EPA

4790898 

Journal Article 

Ion Chromatography with Post-column Reaction and Serial Conductivity and Spectrophotometric Detection Method Development for Quantification of Transition Metal Dissolution in Lithium Ion Battery Electrolytes 

Vortmann-Westhoven, B; Diehl, M; Winter, M; Nowak, S 

2018 

Yes 

Chromatographia
ISSN: 0009-5893
EISSN: 1612-1112 

81 

7 

995-1002 

10.1007/s10337-018-3540-2 

WOS:000436846100004 

We present a method for the separation and determination of transition metals in electrolytes based on ion chromatography (IC) with post-column reaction (PCR) and serial conductivity and spectrophotometric detection. Three IC columns [Metrosep C4-250/4.0 (column A), Metrosep C6-250/4.0 (column B), and Nucleosil 100-5SA-250/4.6 (column C)] with different capacities, and stationary phases were used and compared with each other for method development. All spectrophotometric measurements were carried out with 4-(2-pyridylazo)resorcinol (PAR) as PCR reagent at a wavelength of 500 nm. To characterize the precision of the separation, the selectivity for the analysis of transition metals (nickel, cobalt, copper, and manganese) in the presence of large amounts of lithium and the resolution of the peaks were determined and compared with one another. Furthermore, the limits of detection (LOD) and quantification (LOQ) were determined for the transition metals. The LODs and LOQs determined by column C were as follows: cobalt (LOD/LOQ): 9.4 A mu g L-1/31.3 A mu g L-1, manganese (LOD/LOQ): 7.0 A mu g L-1/23.5 A mu g L-1, and nickel (LOD/LOQ): 6.3 A mu g L-1/21.1 A mu g L-1. Finally, the concentration of transition metal dissolution of the cathode material Li1Ni1/3Co1/3Mn1/3O2 (NCM) was investigated for different charge cut-off voltages by the developed IC method. 

Ion chromatography; Post-column reaction; Spectrophotometric detection; Lithium ion cell; Metal dissolution