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Cost Effective, Optimized Na+ and Multi-Valent Ion Conducting Membranes


Nabatteries, including both NSBs and NMBs, are built upon a Na+ conducting solid state membrane. The most widely used is doped ? ?-Al2O3, a structure of alternating closely-packed slabs and loosely-packed layers that allows for facile transport of Na+ in elevated temperatures. For a satisfactory performance, the Na-batteries are built upon a thick solid electrolyte (?1.0 mm) and operated at 300-350oC. The solid oxide membranes are prepared via sophisticated ceramic processing, including extruding/casting and varied stages of heating or sintering. Alternatively NaSICON has been reported lately for Na-batteries that can operate at lower temperatures than that required for NSBs and NMBs. There however remain challenges for this type of membranes in conductivity, long term stability, etc. In addition to sodium, other membrane chemistries are of interest to enable the usage of other low-cost, multivalent materials (magnesium or aluminum as examples) that would increase energy density and improve cost. Lithium-based chemistries are specifically discouraged from this call. Applications are sought to develop low cost, robust solid state membranes that can allow for satisfactory operation of Naand other multivalent cation-based batteries at temperatures <250oC. An ideal membrane should exhibit: 1) high cation conductivity, 2) excellent structural and mechanical stability, 3) good chemical stability to adjacent components during operation at elevated temperatures, and 4) low cost in raw materials and manufacturing.

Questions – contact Imre Gyuk,

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