| 摘要 |
PURPOSE:To depress the absorption of moisture and improve working properties such as preservation, transportation and assembly by providing a beta-alumina layer against the surface of a solid electrolytic tube body made of beta''-alumina. CONSTITUTION:In a solid electrolytic tube 5, a thin beta-alumina layer 5b having a limited sodium content which is not so sensitive to moisture is formed against the surface of a bottomed cylindrical solid electrolytic tube body 5a made of beta''-alumina by heating only the surface thereof by a gas burner. beta-alumina has a high electric resistance, compared with beta''-alumina. However, the formation of the thin beta-alumina layer on the surface of the body 5a composed of beta''-alumina enables a reduction in influence of water and also provides those having almost the same electric resistance. Hence, even if the tube 5 is preserved in the atmosphere for a long time, the absorption of moisture is depressed, and the sodium ion conductivity is properly maintained. Thus, the reduction in performance of the battery can be prevented. |
