| 摘要 |
PROBLEM TO BE SOLVED: To improve the corrosion resistance of a positive electrode lid or battery jar so as to be contributable to longer life time of a battery by constituting at least one of the positive electrode lid and the battery jar through the use of an iron containing carbon and at least one among lanthanum, cerium, and yttrium, each of which has a specified concentration or less. SOLUTION: At least one of a positive electrode lid 4 and a battery jar 9 is formed of a low carbon steel or iron, containing 0.03% or less of carbon and 0.01-0.3% of at least one of lanthanum, cerium and yttrium. In such a sodium-sulfur battery, the iron preferably has a chromium-iron alloy layer formed by chromizing or a chromium-aluminum-iron alloy layer formed by calorizing on the surface. Accordingly, a chromium-iron alloy layer which is highly corrosion-resistance to sodium polysulfide or a high concentration chromium-aluminum-iron alloy layer which is corrosion-resistance to sodium polysulfide can be formed on the surface.
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