Quantifying the Extent of Improved Li-ion Motion using Quasi-Elastic Neutron Scattering

Sulphide superionic materials are candidate electrolytes for all-solid-state batteries. Quasi-elastic neutron scattering (QENS) is sought to obtain bulk diffusion rates and activation energies for three Li6PS5Cl electrolytes prepared by different methods; a standard cold pressed electrolyte, a heat-treated electrolyte and a spark plasma sintered version. The ionic conductivity of the heat treated and plasma sintered Li6PS5Cl samples are substantially greater than that of the commercial cold pressed material. The post-processing noted above, typically promotes grain growth which leads to enhanced conductivities, however structural modifications when using these post processing methods has also been observed. QENS will allow us to determine the true bulk diffusion, which can then be compared to macroscopic diffusion (which considers bulk, grain boundary, and particle interface diffusion) determined by pulsed field gradient nuclear magnetic resonance allowing us to elucidate which of these factors is rate limiting for effective ion diffusion.