13C hyperpolarized NMR by Dissolution-DNP enables snapshot detection of degradation products in lithium-ion battery electrolytes

Chloé Gioiosa (CRMN Lyon, France)

LinkedIn: @Chloé Gioiosa

Abstract: Dissolution Dynamic Nuclear Polarization (dDNP) is a powerful hyperpolarization technique enabling tremendous sensitivity gains in solution nuclear magnetic resonance (NMR). Over the last decades, researchers’ efforts have led to an extension of dDNP applications in numerous research fields. Lithium-ion batteries are among the most widespread rechargeable batteries, and a proper understanding of the physicochemical reactions at stake inside them is paramount to make them safer, more efficient, and sustainable. One of the key challenges lies in better understanding and limiting the degradation of the battery electrolyte, which can significantly impact the battery’s performance. While NMR has been used in attempts to understand these mechanisms, notably by investigating the degradation products, the intrinsic lack of sensitivity of this technique, combined with the limited accessible volume of such compounds, makes its application often challenging. This work combines several state-of-the-art dDNP methodologies, including using recently introduced hyperpolarizing polymers (HYPOP) to acquire hyperpolarized 13C NMR spectra of degraded battery electrolytes. We show that we can successfully detect 13C signals on formulated battery electrolyte solutions in different degradation stages, on a 600 MHz spectrometer, with sensitivity gains of up to 3 orders of magnitude. This work paves the way for studying lithium-ion battery electrolyte degradation under usage conditions (cycling, thermal aging, air exposure…) with a 13C detection limit below the micromolar range. This methodology has the potential to provide new insights into degradation mechanisms and the role and effectiveness of additives to mitigate electrolyte degradation.