Broadband benchtop NMR is a powerful tool for the quality control of battery electrolytes, it allows rapid feedback on a chemical composition of these complex mixtures. That can include analysis of solvents using ¹H NMR, fluorinated salts and stabilising agents with ¹⁹F NMR, ³¹P and ¹¹B to analyse those same salts as well as ⁷Li and ²³Na to understand the properties of cation species in solution. In this application note we use a combination of ¹H and ¹⁹F NMR to rapidly diagnose the source of observed in-cell performance difference between two commercial Li-ion battery electrolytes. This performance difference is found to be the result of electrolyte degradation resulting from a well known hydrolysis reaction. ¹⁹F NMR reaction monitoring is then used on a similar electrolyte to understand the competing kinetics of the degradation reaction allowing for more complete understanding of this process which could lead to better ways of stabilising future electrolytes. Finally, pulsed field gradient NMR is used to measure observable differences in the physical properties of “good” and degraded electrolytes.

By downloading this application note you will learn:

• how broadband benchtop NMR gives rapid feedback on electrolyte quality
• how reaction monitoring allows understanding of electrolyte degradation processes
• how these degradation processes affect key electrolyte physical properties