Nanoscale pore measurements in an all-solid-state lithium-ion battery with ultra-small-angle X-ray scattering (USAXS)

In a high performance all-solid-state lithium-ion battery (ASSLiB), lithium-ion should be smoothly transported to minimize overpotential. Nanoscale pores in the ASSLiB can inhibit ionic transportation; therefore, the pore structure should be measured and nanoscale pores should be prevented for high performance batteries. In this study, laboratory-scale ultra-small-angle X-ray scattering (USAXS) measurements are proposed to evaluate the nanoscale pores in ASSLiBs. The results measured with the USAXS are validated by comparing them with synchrotron radiation (SR) X-ray nanotomography data. The pore volumetric density distributions from the USAXS measurements are very close to those from SR X-ray nanotomography; this demonstrates that the nanoscale pores in ASSLiBs can be measured by USAXS. USAXS measurements of pore structures of solid electrolytes prepared from micron-scale and submicron-scale particles solid electrolyte (SE) reveal that the pore structure is not simply dependent on the SE particle size.