Patent ID: 10818968

Abstract:
A method of preparing a gallium-doped LLZO solid electrolyte includes (a) preparing a solid electrolyte precursor slurry by subjecting a mixed solution comprising a metal aqueous solution including lanthanum (La), zirconium (Zr) and gallium (Ga), a complexing agent and a pH controller to coprecipitation; (b) preparing a solid electrolyte precursor by washing and drying the solid electrolyte precursor slurry; (c) preparing a mixture by mixing the solid electrolyte precursor with a lithium source; (d) preparing a gallium-doped LLZO solid electrolyte represented by Chemical Formula 1 below by calcining the mixture at 600 to 1,000° C.; and (e) thereafter sintering the solid electrolyte represented by Chemical Formula 1 at 1,000 to 1,300° C. By adjusting amounts of starting materials and controlling flow rates of supplied materials, a high-precision cubic structure with improved sintering properties is obtained and ionic conductivity of the solid electrolyte is increased. LixGayLazZrwO12, (5≤x≤9, 0<y≤4, 2≤z≤4, 1≤w≤3).  Chemical Formula 1