Gas chromatography/Fourier transform infrared/mass spectrometry coupling: a tool for Li-ion battery safety field investigation†
As electric vehicles may have a positive impact on global warming, worldwide endeavour is devoted to improving the performance, durability and safety of Li-ion batteries considered as the most promising technology. To help the characterisation and identification of volatile compounds released upon batteries ageing or during a system malfunction-induced thermal event, we implemented the coupling of the gas chromatography (GC) technique with mass spectrometry (MS) and Fourier transform infrared (FTIR) analytical tools. Through two detailed examples related to the thermal runaway phenomenon and the battery swelling, this paper provides evidence that the complementarities of these techniques allow us to detect and then accurately identify a vast array of volatile molecules ensuing from electrochemically/chemically driven electrolyte degradation. Hence, this GC/FTIR/MS equipment will be powerful in studying the impact of new electrolyte molecules on the battery functioning or safety and in assessing its degradation state after long-term or unexpected premature capacity loss.