| 摘要 |
PURPOSE:To prevent the degradation of solid electrolyte and attain the elongation of cell life by impregnating a porous absorber with at least one part of sodium which is a cathode active material. CONSTITUTION:High purity active carbon 13 as a porous absorber is immerged in the lower end part of sodium 2 which is a cathode active material. Stopping protrusions 14 prevent the floating-up of the porous absorber. Though the liquid surface L of the sodium varies up and down according to charge or discharge, at the time that the porous absorber 13 is being immerged in the lower end part of the sodium such as this, the porous absorber 13 has no possibility to be exposed above the liquid surface, even if the liquid surface varies up and down. Absorbent has function to absorb alkali and alkali-earth metals with electrochemically positive polarity such as kalium ion (K<+>), calcium ion (Ca<2+>), etc., which are impurities in the molten sodium 2, in its surface. That is, alkali and alkali-earth metals such as kalium ion (K<+>), calcium ion (Ca<2+>), etc., are more positive than sodium ion (Na<+>), therefore selectively absorbed. |
