Our lab focuses on understanding the impact of microstructure and phase composition on the mechanical strength and on the ionic conductivity of the sodium-b’’-alumina electrolyte. These two properties are directly correlated with the power capability of the battery, but also with production cost, as thinner electrolytes results in improved power capability, but lower yield in production. Although known since the 1970s, processing of sodium-β’’-alumina into a dense material with high ion conductivity is challenging, in particular due to significant sodium loss during sintering. Reports in literature relating microstructure to ionic transport properties are lacking and reported values for the ionic conductivity vary significantly. We developed a detailed understanding, how microstructure and phase composition affect ionic conductivity and mechanical strength. Our results are also relevant for related ceramic electrolytes for all-solid-state lithium-ion batteries.
Swiss Federal Office of Energy, InnoSuisse, Horizon 2020
 D. Landmann, G. Graeber, M.V.F. Heinz, S. Haussener, C. Battaglia, Sodium plating and stripping from Na-β''-alumina ceramics beyond 100 mA/cm2, Materials Today Energy, 2020, 18, 100515.
 G. Graeber, D. Landmann, E. Svaluto-Ferro, F. Vagliani, A. Turconi, M.V.F. Heinz, C. Battaglia, Rational cathode design for high-power sodium-nickel chloride batteries, Adv. Funct. Mater. 2021, 210667.
 M.-C- Bay, M. Wang, R. Grissa, M. Heinz, J. Sakamoto, C. Battaglia, Sodium plating from Na-b''-alumina ceramics at room temperature, paving the way for fast-charging all-solid-state batteries, Adv. Energy Mater. 2019, 1902899.
 M.-C. Bay, M. V. F. Heinz, R. Figi, C. Schreiner, D. Basso, N. Zanon, U. Vogt, C. Battaglia, ACS Appl. Energy Mater. 2018, 2, 687.