Corrosion sodium sulfur battery

A prerequisite of long-life sodium/sulfur batteries is that the cells contain suitable corrosion-resistant materials which withstand the aggressively corrosive environment of this high—temperature system. Stackpool and Maclachlan have reported on investigations in this field [17], The components in an Na/S cell are required to be corrosion-resistant towards sodium, sulfur and especially sodium polysulphides. Four cell components suffer particularly in the Na/S environment the glass seal, the anode seal, the cathode seal, and the current collector (in central sodium arrangements, the cell case). 

Much of the effort to develop the Na/S battery was aimed at its use in electric vehicles. Current applications of this advanced battery system are now mainly in the stationary battery area, but feasibility studies were done on the recycling of this system before the EV development efforts were suspended. Sodium/sulfur batteries contain reactive and corrosive materials, but not toxic ones. By treatment of the battery waste, the reactivity problems can be removed. 

Reclamation. Ultimately all batteries, including sodium/sulfur, will reach their end of life and must be reclaimed or disposed of in some manner. In addition to sodium and sulfur, sodium polysulflde is classified as a hazardous material because of its corrosivity. Chromium or chromium compounds are still being used as coatings for containment corrosion protection. Therefore sodium/sulfur batteries used in all terrestrial applications have to be returned to a processing center for proper recycling, reclamation, or disposal. 

Minck, R. W. (1982) Corrosion problems of the sodium-sulfur battery. DOEMeetingonHigh TemperatureCorrosionProblems in Battery Systems, London, 13-14 July 1982 Minck, R. W. (1983) Practical experiences with beta-alumina. Research Assistance Task Force Meeting en Beta-Alumina for Sodium-SulfurCells, Oak Ridge,Tennessee, USA 8-10March 1983... 

Sodium cells20-23 operate at fairly high temperatures (300-400 °C) and require an inert atmosphere (argon) in a sealed, corrosion-resistant vessel (e.g., Cr-coated steel). Furthermore, leakage of liquid Na could obviously have dire consequences. Nevertheless, sodium-sulfur cells have received serious consideration as rechargeable batteries ... 

Sodium/sulfur and sodium/metal chloride technologies are similar in that sodium is the negative electrode material and beta-alumina ceramic is the electrolyte. The solid electrolyte serves as the separator and produces 100% coulombic efficiency. Applications are needed in which the battery is operated regularly. Sodium/nickel chloride cells have a higher open-circuit voltage, can operate at lower temperatures, and contain a less corrosive positive electrode than sodium/sulfur cells. Nevertheless, sodium/nickel chloride cells are projected to be more expensive and have lower power density than sodium/sulfur cells. 

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