Structure Prediction of Li–Sn and Li–Sb Intermetallics for Lithium-Ion Batteries Anodes

High Resolution Image Download MS PowerPoint Slide A variety of new stable and metastable Li–Sn and Li–Sb intermetallics are presented using the ab initio random structure searching (AIRSS) and species swapping methods. These include LiSn 2 – P 4/ mmm, Li 2 Sn 3 – P 1̅, Li 7 Sn 9 – P 4 2 / n, Li 3 Sn 2 – P 2 1 / m, Li 5 Sn 3 –Im3̅ m, Li 2 Sn– Cmcm, Li 8 Sn 3 – R 3̅ m, Li 3 Sn– P 3 2, Li 7 Sn 2 – P 1̅, Li 4 Sn– P 2 1, Li 5 Sn– P 6/ mmm, Li 7 Sn– Fmmm, LiSb– P 4/ mmm, Li 8 Sb 5 – Fd 3̅ m, Li 8 Sb 3 – P 2/ c, Li 4 Sb– C 2/ m, Li 9 Sb 2 – P 3̅ m 1, Li 5 Sb– P 6/ mmm, Li 6 Sb– R 3̅ m, Li 8 Sb– Pc, and Li 9 Sb– Cmcm . The Li–Sn theoretical voltage curve was calculated to high accuracy mainly from experimentally known structures and shows excellent agreement with experimental electrochemical cycling measurements previously reported. Li 2 Sn was found on the convex hull to within density-functional theory accuracy, and its mechanical stability was investigated by calculating the density of states of the phonon spectrum. The new structures obtained by AIRSS show a consistent structural evolution of Li–Sn phases as Li concentration is increased. First-principles NMR calculations on the hexagonal and cubic Li 3 Sb phases are performed. Our NMR results are compared to findings of Johnston et al. ( Chem. Mater. 2016, 28, 4032) and proposed as a diagnostic tool to interpret experimental data.