Research Project

In-situ and ex-situ NMR studies of lithium-ion-battery (LIB) and sodium-ion-battery (SIB) materials

The launch of research programs based on the development of innovative and more efficient carbon-free technologies for the electrification of the grid and the automotive transportation will be needed to fulfill the goal—to avoid severe climate change proposed at the Paris Climate Summit. Electrochemical energy storage and the characterization of batteries (LIB and SIB are of great importance in this field) are such programs and are also huge fields with many suppliers for materials and devices as well as numerous approaches to combine ideas, knowledge, and practical skills.

Chemical and electrochemical processes depend on redox reactions. Ions such as Li+and Na+are often directly involved in these processes and corresponding6;7Li and23Na NMR spectra, respectively, are influenced by the electronic structure of the materials under investigation. Hence it is often possible to distinguish between insulators and conductors as well as diamagnetic and paramagnetic contributions. Furthermore, the range of nuclei that can be used to gain insights into electronic and structural changes of the material (direct or indirect) is not limited to Li and Na only. Many other nuclei, e.g., I = 1/2 isotopes like 1H,13C,19F,29Si,31P, and119Sn as well as quadrupolar nuclei with I > 1/2 like2H,17O,27Al and51V, can provide useful insights.

Ex situ and in situ NMR experiments are of considerable interest because the former one traces different sites or species in different stage of electrochemical reactions; the latter one even enables monitoring of structural and electronic changes of the materials while the electrochemical process are happening. ssNMR can also obtain insights into structure and dynamics, which draw significant attention of scientists.