Volatilization of Na 2 O and Its Impact on the Processing of Solid Electrolytes

This study explores the volatilization of Na 2 O from selected solid and liquid materials, especially from a Na + superionic conductor (NaSICON) with the composition Na 3.4 Zr 2 Si 2.4 P 0.6 O 12 , with the aim of addressing the often arbitrarily chosen amount of additional sodium source used to compensate for mass loss during sintering. The measured and calculated mass losses allow for a more precise estimate of the necessary Na 2 O additions during component manufacturing on a larger scale. The practical relevance of this is discussed in the context of manufacturing tape‐cast separators for battery applications. In addition, the volatilization of Na 2 O from molten sodium silicophosphate glass and sodium phosphate is investigated in different crucible materials and atmospheres to elucidate the impact of experimental parameters, different physical states, and volatilization kinetics. With knowledge of thermodynamic processes and the vapor pressure curve, mass losses can be calculated in very good agreement with the observed data.