Depending on the performed analysis you can extract different parameters.
If following the Bruce-Vincent method you can extract the lithium transference number, if needed.
Other analysis, such as cronopotentiometry testing at constant current, will provide the mechanical stability of the electrolyte against dendrite growth.
Instead, if you perform Electrochemical Impedance Spectroscopy you can obtain the resistance of the system and, knowing the geometrical parameters, the ionic conductivity.
Some examples can be found here: Article Composite solid-state electrolyte based on hybrid poly(ethyl...