Analyzing potassium-ion diffusion in aqueous solutions through pulsed-field gradient NMR

Abstract The diffusion behavior of potassium ions in aqueous solutions is crucial for advancing both fundamental science and practical applications. Pulsed-field gradient nuclear magnetic resonance (PFG-NMR) is a powerful technique for evaluating ion diffusion. However, its application to potassium has been limited by low Larmor frequency. This study reports the successful measurement of potassium-ion diffusion coefficients in various salt solutions using 39K PFG-NMR through optimizing experimental conditions. The reported data will benefit the development of advanced devices such as potassium-ion batteries.