| 摘要 |
PROBLEM TO BE SOLVED: To obtain a β"-alumina ceramic sintered compact having high mechanical strength and a sodium-sulfur secondary battery using the sintered compact. SOLUTION: When powdery starting material is produced so as to obtain a β"-alumina ceramic sintered compact having a uniform fine structure and high mechanical strength, α-alumina, a sodium salt and a structure stabilizing agent such as a lithium salt are mixed, pulverized and subjected to phase transition to β"-alumina by heat treatment in a vessel made of a spinel compd. consisting of magnesium oxide or magnesium and aluminum or made of magnesium oxide to which <40% magnesium-aluminum spinel has been added. |
