Solid-state NMR studies of lithium ion dynamics across materials classes: Review update

Lithium containing solids exhibit interesting ion conducting properties because of the dynamic nature of Li+ ions. A variety of lithium solid-state NMR experiments constitute an excellent toolbox to characterize the different facets and extents of Li+ ion dynamics in solids. This review focuses on reported NMR attempts to elucidate Li+ dynamics in solids in about the past 5 years and is an update of our previous review in Ann. Rep. NMR Spectrosc. 89 (2016) 1–102. Materials which are good candidates to be used as components in lithium ion batteries or arouse basic interest in the Li ion dynamics are mentioned in this review together with fundamental parameters which govern their ion conducting behaviour. They are Li+ diffusion coefficients, ionic jump rates, activation energies and dimensionality of diffusion. The diffusion mechanisms and pathways are elucidated for a variety of materials classified based on their chemical and structural differences. Alongside the NMR methods broadly applied to Li already before 2016, some like In Situ/Operando NMR, Beta-NMR, and Field Cycling NMR have gained increased attention in the study of Li+ ion dynamics and diffusion in solids.