Probing Li ion dynamics in amorphous xLi2SO4⋅(1 − x)LiPO3 by quasielastic neutron scattering.

Abstract The diffusion dynamics of a series of lithium sulfate substituted phosphate glass materials xLi 2 SO 4 ⋅(1 − x)LiPO 3 has been probed by quasielastic neutron scattering. Amorphous Li ion conductors are attractive as electrolyte materials for all-solid state batteries because they are highly isotropic and chemically stable. Local disorder is expected to reduce barriers to ion migration – leading to improved ionic conductivity relative to their crystalline counterpart – while minimizing unwanted electron transport. We report Li self-diffusion in these materials on a length scale comparable to the interatomic spacings, obtaining values D ≃ 55 ± 4 × 10−8 cm2/s at 450 K. Elastic neutron scattering measurements show an alteration of the phosphate chain backbone of the glass material. Highlights • Amorphous Li electrolyte materials xLi 2 SO 4 (1-x)LiPO 3 are probed via quasielastic neutron scattering • Li ion diffusion is found to isotropic on length (few Å) and time scales (ns) probed by neutron backscattering spectroscopy • The diffusion constant for compositions x=0.3 & 0.4 is found to be 55x10−8 cm/s, diffusion for x=0 was below detection limit. [ABSTRACT FROM AUTHOR]