ИСТИНА

We now observe a new wave of increasing interest to superionic conductors, primarily to lithium and sodium solid state electrolytes. There could be various reasons for that, however, the works on all-solid-state batteries are the one of the main drivers. It is empowered by both fundamental interest, concerning the interfacial issues, and practice focusing on the development of safe and powerful energy storage systems. In our work, we demonstrate that the ionic conductivity of well-known Li1+xAlxGe2-x(PO4)3 glass-ceramic electrolytes can be tailored by Y2O3 additive to Li2O–Al2O3–GeO2–P2O5 melts. We found that addition of 5 vol. % of Y2O3 causes noticeable changes in further glass crystallization process as the key parameters (glass crystallization temperature, viscosity and others) are affected. Small-angle neutron scattering data suggest that Y-containing glasses are suddenly crystallized upon heat treatment producing uniform Li1+xAlxGe2-x(PO4)3 ceramics. Due to lower resistance of intergrain interfaces such samples demonstrate 0.5 mS/cm specific ionic conductivity that is nearly 5 times higher in comparison to Y-free ceramics, prepared in similar conditions. We speculate that such an effect is caused primarily by better intergrain contact in Y-containing ceramics along with a better ionic transport in grain bulk as evidenced by 7Li NMR. We further use the LAGP powders obtained by grinding of glass-ceramics for fabrication of thin (30 – 100 microns) by tape-casting.