Investigating Lithium-Ion Batteries using Low-Field Nuclear Magnetic Resonance and Relaxometry: A Short Story
Lithium-ion batteries provide lightweight, energy dense, and efficient power for portable electronics and electric vehicles. Accompanying the rise of lithium battery technology is the need for fast, non-destructive diagnostic techniques to determine important battery performance or safety parameters. Low-field NMR and relaxometry is an ideal technique to probe lithium-ion polymer (LiPo) batteries due to its ability to penetrate the aluminum casing of these batteries. The development of a few different low-field techniques are presented here to measure different battery parameters. This includes measuring the T_1 and T_2 relaxation times of LiPo batteries at differing states of charge, magnetic resonance imaging showing T_2 as a function of position across a battery, and using pulsed field gradient 7Li nuclear magnetic resonance (NMR) to measure Li diffusion coefficients.