The invention relates to a LLZO preparation method, a thermal
cell quasi-
solid electrolyte, and a preparation method thereof. The preparation method of the quasi-
solid electrolyte comprises followingsteps: raw materials including Li2CO3, La2O3, ZrO2, H2C2O4, and an
alkali metal halide are subjected to purification treatment, the needed Li2CO3, La2O3, H2C2O4, and ZrO2 are weighed, are grinded to be uniform, and are introduced into a sealed stainless steel tank for
roasting at 1200 DEG C, natural cooling is carried out, an obtained product is subjected to ball milling to be uniform so as to obtain the
lithium lanthanum zirconium oxygen solid state
electrolyte (Li7La3Zr2O12, LLZO); the LLZO and an
alkali metal halide co-
molten salt are mixed again, the temperature is increased to 400 to 500DEG C under protection of
argon gas rapidly, repeat
vacuum pumping and slow pressurizing are carried out so that infiltration of the co-
molten salt into the porous LLZO is realized, natural cooling iscarried out, and an obtained product is subjected to ball milling so as to obtain the thermal
cell quasi-solid electrolyte. The prepared thermal
cell quasi-solid electrolyte is low in
crystal boundary resistance, and high in
ion mobility, and
heat stability.