Preparation method of thermally stretchable modified LAGP glass and ceramic electrolyte fiber

The invention discloses modified LAGP glass capable of being thermally stretched, the structural general formula of the modified LAGP glass is Li < 1.5 + x > Al < 0.5 > Ge < 1.5 > P < 3-x > SixO12. YM. ZN, M is a rare earth oxide, N is a fluxing agent, x is more than or equal to 0 and less than or equal to 0.5, y is more than or equal to 0 and less than or equal to 0.1, and z is more than or equal to 0 and less than or equal to 0.15. The thermally stretchable modified LAGP glass can be prepared by melting at 1200-1300 DEG C by a melting quenching method, compared with the prior art, the thermally stretchable modified LAGP glass has the advantages that the thermal stability is good, the glass transition temperature range T is more than 100 DEG C, the thermally stretchable modified LAGP glass can be drawn into fibers at 100-120 DEG C above the DSC temperature, ceramic electrolyte fibers can be obtained through high-temperature crystallization treatment, and the thermally stretchable modified LAGP glass has the