We calculate the ionic conductivity using 𝜎 = 𝑡 𝑅 𝑏 𝐴 where t is the thickness and A is the area of the pelletized solid-state electrolyte. The corresponding Nyquist plots and ionic conductivities are shown in Figure . The measured conductivities of LIC, LYC, LPSC and LAGP agree with previous reports . In LAGP, the measured ionic conductivity increased after sintering, but still remained low, typical when the grain boundary resistance is high . Larger grain boundary resistance did not affect NMR measurements as the NMR results in LAGP did not change significantly before and after sintering. respectively. The relaxation rates 1/T1 , 1/T2 , 1/T2* and 1/T1,δ are plotted as a function of temperatures for in Figure .