Solutal convection

Solutal convection appears in the positive electrode of a liquid metal battery. Discharing such a cell, a light metal alloys into a heavy metal. When reversing the current flow - and charging the liquid metal battery - light metal is removed from the surface of the positive electrode. Consequently, heavy metal accumulates at the surface. This local concentration gradient leads to a density gradient and to flow structures as shown below.

Solutal convection appears only when charging a liquid metal battery. It enhances mass transfer and thereby improves the efficiency of the cell. Discharge of a liquid metal battery leads in contrast to a stable density stratification. This in turn suppresses fluid flow.

Moreover, solutal convection can in certain cells also be observed in the electrolyte layer of liquid metal batteries.

Publications

• Duczek, C.
  Modeling electrochemical processes in liquid metal batteries with a focus on mass transfer in molten salt electrolytes
  PhD thesis, Technische Universität Dresden (2025)
• Personnettaz, P.; Landgraf, S.; Weier, T.; Weber, N.; Eckert, S.
  Schaltungsanordnungen mit elektrochemischer Zelle und Verfahren zum Betrieb einer elektrochemischen Zelle
  German patent DE 10 2020 134 881
• Duczek, C.; Weber, N.; Nash, W.; Sarma, M.; Weier, T.
  Solutal convection in Na–Zn liquid metal batteries and its impact on self-discharge
  Physics of Fluids 37(2025) 023370
• Duczek, C.; Horstmann, G. M.; Ding, W.; Einarsrud, K. E.; Gelfgat, A. Y.; Godinez-Brizuela, O. E.; Kjos, O. S.; Landgraf, S.; Lappan, T.; Monrrabal, G.; Nash, W.; Personnettaz, P.; Sarma, M.; Sommerseth, C.; Trtik, P.; Weber, N.; Weier, T.
  Fluid mechanics of Na-Zn liquid metal batteries
  Applied Physics Reviews 11(2024), 041326
• Personnettaz, P.; Klopper, T. S.; Weber, N.; Weier, T.
  Layer coupling between solutal and thermal convection in liquid metal batteries
  International Journal of Heat and Mass Transfer 188(2022) 122555
• Weber, N.; Duczek, C.; Horstmann, G.M.; Landgraf, S.; Nimtz, M.; Personnettaz, P.; Weier, T.; Sadoway, D.R.
  Cell voltage model for Li-Bi liquid metal batteries
  Applied Energy 209(2022) 118331
• Personnettaz, P.; Landgraf, S.; Nimtz, M.; Weber, N.; Weier, T.
  Effects of current distribution on mass transport in the positive electrode of a liquid metal battery
  Magnetohydrodynamics 56(2020) 247-254
• Herreman, W.; Bénard, S.; Nore, C.; Personnettaz, P.; Cappanera, L.; Guermond, J.-L.
  Solutal buoyancy and electrovortex flow in liquid metal batteries
  Physical Review Fluids 5(2020) 074501
• Personnettaz, P.; Landgraf, S.; Nimtz, M.; Weber, N.; Weier, T.
  Mass transport induced asymmetry in charge/discharge behavior of liquid metal batteries
  Electrochemistry Communications 105(2019) 106496
• Kelley, D.; Weier, T.
  Fluid mechanics of liquid metal batteries
  Applied Mechanics Reviews 70(2018) 020801