Manufacture, 3"-alumina electrolyte tubes

The manufacture of P"-Pl20 tubes for batteries should result in a product with high sintered density, fine closed porosity, low electrical resistivity, good mechanical strength, and close dimensions. The formation of 73"-alumina electrolyte depends on the starting materials as well as on the production process itself Different starting materials necessitate different production routes. Some key requirements which strongly influence the production process must be mentioned ... 

Almost all practical sodium-sulphur cells are based on electrolytes formed as closed tubes. These are usually manufactured by isostatic pressing, or electrophoretic deposition of powdered /3-aluminas (or their precursors)... 

Alkali metal thermo-electric converters (AMTEC) are high-efficiency (>35%) cells for the production of electricity from heat(7). A key component of this cell, as well as of Na/S batteries, is a nonporous, P"-alumina ceramic electrolyte that conducts Na ions when either system is operating ( 800 C for AMTEC, 400 C for Na/S). Despite the high performance ratings for both power sources, their widespread use is limited by a very high cost of production. The manufacture of high quality P"-alumina tubes contributes to this high cost. 

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