skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Technical Report ·
DOI:https://doi.org/10.2172/7126769· OSTI ID:7126769

Work during the past year on the development of a sodium--sulfur battery system for bulk storage of energy is described. Two initial cell/module/system designs are discussed. The cell in these preliminary designs consists of many individual beta-alumina tubes used as the separator between single sodium and sulfur compartments. Heat conduction experiments were made and a complete thermal analysis of the system is given. Progress on construction of a 45-tube cell is given. A comparative cost analysis of the above multitube designs with designs consisting of bundles of cylindrical single-tube cells indicated that the latter approach would probably have a cost advantage. A statistical analysis of the effects of failure or change in performance of individual cells or modules and a study on optimization of the system cost were performed. Improvements in the microstructure, grain boundary resistance, and surface uniformity of the ceramic electrolyte resulted in cells with lower resistance and no sign of ceramic degradation after more than six months of continuous charge and discharge at constant current. Over 300 Ah/cm/sup 2/ was obtained with no limit evident, and the surface resistance problem was solved. Improvements in the design of the graphite current collector resulted in consistently high cell capacity. The utilization of sulfur achieved increased up to a value of 95%. A few cells using stainless steel containers showed no decrease in either cell capacity or cell resistance up to the present extent of testing (190 cycles for one cell) or to the time of failure due to seal failures. Supporting research included corrosion studies on container materials, sodium motion and defect structure in beta alumina, pressure--temperature stability of ..beta.. and ..beta..''-alumina, and the effects of grain orientation on the electrical properties of beta-alumina. 60 figures, 26 tables.

Research Organization:
General Electric Co., Schenectady, NY (USA). Research and Development Center
OSTI ID:
7126769
Report Number(s):
EPRI-EM-266
Country of Publication:
United States
Language:
English