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Title: Development of sodium--sulfur batteries for utility application. Interim report

Technical Report ·
DOI:https://doi.org/10.2172/6801378· OSTI ID:6801378

The results of the past sixteen months of a project aimed at developing sodium--sulfur batteries for utility applications are presented. Over 150 small (16-Ah) cells were placed on test. Lifetimes up to 12,000 hours and up to 1,150 Ah/cm/sup 2/ were obtained. Cell capacities of over 80% were achieved and sustained for over 250 cycles. The most common failure mode during the period involved degradation of the glass seal between the beta-alumina tube and the alpha-alumina header. Thermocompression bonding of steel containers to the alpha alumina insulator was chosen as the first choice for the exterior seals. A new glass formulation has so far eliminated the problem with the interior beta- to alpha-alumina seal; no failures have occurred in the six months of cell testing since it was put into use. The basic unit of the system is a module which is a thermally self-sufficient package. It consists of 360 cells (300 Wh each). The cells within the module are arranged in nine bundles in series, each bundle consisting of forty cells connected in parallel. Manufacturing the cost studies of two kinds are presented. One is a cost projection for a battery system of commercial size, 100 megawatt-hours. The estimated selling price is projected to be about $38/kWh. The other study is an examination of the effect of the ceramic electrolyte tube size on the system selling price. Finally, a summary of supporting research activities is given. 68 figures, 31 tables.

Research Organization:
General Electric Co., Schenectady, N.Y. (USA). Corporate Research and Development Dept.
OSTI ID:
6801378
Report Number(s):
EPRI-EM-683
Country of Publication:
United States
Language:
English