METHOD FOR PREPARING SOLID ELECTROLYTE MATERIAL FOR ALL-SOLID-STATE LITHIUM SECONDARY BATTERY USING COMPLEX PROCESS AND METHOD FOR MANUFACTURING ALL-SOLID-STATE LITHIUM SECONDARY BATTERY COMPRISING THE SAME

摘要

(A) preparing a solid electrolyte precursor by coprecipitation reaction of a metal nitrate including lanthanum nitrate and zirconium nitrate, a complexing agent, and a mixed aqueous solution containing a pH controlling agent; (b) washing and drying the solid electrolyte precursor; (c) mixing the dried solid electrolyte precursor, any one selected from tantalum (Ta) oxide and niobium (Nb) oxide, and a lithium source to prepare a mixture; And (d) calcining the mixture to prepare a Ta or Nb doped lithium lanthanum zirconium oxide (LLZO) solid electrolyte (Ta / Nb doped LLZO) doped with either tantalum or niobium A method for producing a solid electrolyte comprising the steps of: Thus, the ion conductivity can be improved by doping a different element such as niobium or tantalum, controlling the composition of the precursor and the lithium source to control the sintering property, and controlling the crystal structure. In addition, by using the above-described method for producing a solid electrolyte in a method for manufacturing a pre-solid lithium secondary battery, the efficiency of the battery can be improved.