Glass-ceramic joining material for sodium-based battery

This study focuses on the design, characterization and testing of a new glass-ceramic sealant for Na-based batteries. The thermo-mechanical properties as well as the sintering behaviour of the new sealant have been characterized by thermal analyses and x-rays diffraction studies. The exothermic peak in the differential thermal analysis plots has been assigned to the crystallization of a calcium sodium aluminum silicate (anorthite sodian), as confirmed by the X-ray diffraction data. The activation energy for the crystallization was found to be 482.3 kJ/mol. The compatibility at the interface between the glass-ceramic sealant and beta- and alpha-alumina is examined before and after corrosion test with molten Na. Tests of this novel silica-based glass-ceramic sealant with Na at 300 °C for 250 h in a real battery operating conditions showed no reactions with Na or evidence of corrosion, as demonstrated by SEM post mortem examinations after cell disassembly.