Contact

Dr. Tom Weier

Head Liquid metal battery
t.weierAthzdr.de
Phone: +49 351 260 2226

Thermal effects in liquid metal batteries

During charge and discharge of a liquid metal battery, heat will be release by Ohmic heating. The heat will be transfered by convection, conduction and radiation. A thermal management ensures that the global cell temperature stays in the desired range (fig. 1).

Thermal effects LMB

Fig. 1: Convection, radiation and heat conduction interact in a liquid metal battery.

The electrolyte layer (consisting of a molten salt) has the highest resistance of the three phases; fig. 2 shows a typical temperature profile. The bottom metal will be heated from above - it will be stably stratified. The upper metall will be heated from below - convection will set in.

Temperature profile

Fig. 2: Typical vertical temperature profile in a liquid metal battery.

Typically, thermal convection cells will appear in the upper metal layer and the electrolyte. At HZDR we study Rayleigh-Bénard convection with the objective of enhancing mass transfer and increasing the efficiency of liquid metal batteries. For that purpose we developed recently a multiphase solver for OpenFOAM using the Oberbeck-Boussinesq approximation for describing thermal convection in all three liquid layers.

Rayleigh-Benard convection LMB

Fig. 3: Thermal convection in the anode of a liquid metal battery.

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