Precisely Quantifying Electrolyte Residues in Aqueous Samples with Newly Developed Method

The recycling of lithium ion batteries is essential to achieve a circular economy. Using water during the mechanical treatment – one of the first steps in the recycling process – is under investigation. However, the generation of process water containing hazardous battery material is a drawback of wet-shredding. To purify such wastewater and recirculate it back into the environment, it is essential to accurately quantify residues even in low concentrations. A team from MEET Battery Research Center at the University of Münster has now developed a method that can be used to precisely determine organic electrolyte residues in aqueous samples. 

Detect Low Concentrations Using a Method Mix

“To prepare the substances for gas chromatographic analysis, we first transferred them quantitatively into an organic solvent by solid phase extraction,” says Julius Buchmann, PhD student at MEET Battery Research Center and the International Graduate School BACCARA (Battery Chemistry, Characterization, Analysis, Recycling and Application). This procedure enabled the researchers to additionally concentrate the sample. As a result, the team achieved very low detection limits.

Subsequently, the scientists analyzed the prepared samples using gas chromatography (GC) coupled with flame ionization detection (FID). This technique can be applied to identify and quantify volatile components of lithium ion batteries, such as the main components and main aging products of the electrolyte. “Our newly developed method is robust and ready for use in the recycling process,” summarizes Buchmann.

Detailed Results Online Available

The entire study has been published by the Julius Buchmann, Yixin Song, Dr Simon Wiemers-Meyer and Dr Sascha Nowak, MEET Battery Research Center, as well as Prof. Dr Martin Winter, MEET Battery Research Center and Helmholtz Institute Münster, in the journal “Advanced Energy and Sustainability”.