SODIUM--SULPHER BATTERY SYSTEM

The development of the hollow-glass-fiber sodium--sulfur battery progressed significantly. Glass fiber quality improved greatly, and the fiber spinning and assembly machinery was made capable of more uniform operation. Impurities in the sulfur, including H, C, Zn exp ++ , and Al exp +++ , do not appear to affect cell lifetime, while impurities in the Na are important. The Ca and ''oxide'' contents of the Na must be held to low levels. Corrosion products of a 316 stainless steel case are harmless to at least 75-day lifetimes. The Mg content of aluminum alloys can leach out in the catholyte and cause cell resistance to increase. Lifetime does not seem to be a function of total current passed or current density across the fibers. On 1000-fiber, 0.5-Ah cells, over 1400 deep charge--discharge cycles were achieved in 75 days of operating life. A larger 5-Ah cell went through 130 cycles at over 80 percent depth. Cell resistance and capacity remained constant, even at the exp 1 / sub 2 hour rate. At lesser depths of discharge, the cells lasted longer. Failure was usually in the fibers when ''dirty'' Na was used, and usually just below the tube sheet when ''clean'' Na was used. An updated estimate of ''cost for sale'' of the bare cell is approximately $23.15 per kWh, based on 0.8-kWh cells. 21 figures, 3 tables. (ERA citation 02:048834)

  • Corporate Authors:

    Dow Chemical Company

    2800 Mitchell Drive
    Walnut Creek, CA  USA  94598

    Energy Research and Development Administration

    20 Massachusetts Avenue, NW
    Washington, DC  USA  20590
  • Authors:
    • Levine, C A
  • Publication Date: 1976-11-1

Media Info

  • Pagination: 68 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00169502
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: EY-76-C-02-2565
  • Files: TRIS
  • Created Date: Mar 14 1978 12:00AM