Method for producing garnet-type compound, garnet-type compound, and all-solid lithium secondary cell containing said garnet-type compound

摘要

The present invention provides a production method that can produce a garnet-type compound containing zirconium and lithium, the compound being in the form of fine particles, with high productivity. The method produces a garnet-type compound containing Zr, Li, and element M¹ (wherein M¹ is at least one element selected from the group consisting of La, Sc, Y, and Ce) as constituent elements. The method includes a first step of (1) mixing a first raw material and a second raw material to obtain a precipitate, the first raw material being a solution containing a zirconium carbonate complex and having a pH of at least 7.0 and not more than 9.5, and the second raw material containing a compound containing the above element M¹ as a constituent element; and (2) a second step of mixing the precipitate and a third raw material containing Li as a constituent element to obtain a mixture, and then firing the mixture at a temperature of less than 1,000° C. to obtain a fired product. The first raw material is prepared by mixing, at a prescribed molar ratio, at least a compound that contains a carbonate species and a compound that contains a zirconium species.