| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject solid electrolyte highly reliable as a solid electrolyte as a constituent of sodium-sulfur cells by specifying the ratio for Li2 O and Na2 O in stock powder and also specifying the composition and crystal form of a seed crystal to be added to the stock powder. SOLUTION: This β"-alumina sintered solid electrolyte is produced by adding a seed crystal to and dispersing it in stock powder comprising Li compound powder, Na compound powder and Al compound powder followed by molding and then sintering, under the following conditions: (1) weight ratio: Li2 O/Na2 O is 0.078-0.1 in terms of oxide in the stock powder; and (2) for the seed crystal, weight ratio: Li2 O/Na2 O is 0.081-0.15, and >=50 (pref. >=80)% crystal form thereof being β"-alumina phase, and the above weight ratio being greater than that in the stock powder. This β"-alumina sintered compact is 1.5-2.5 Ωcm in resistivity at 330 deg.C and 250-350 MPa in radial crushing strength. |
