Thermal convection in a liquid metal battery

TL;DR

This paper analyzes thermal convection in liquid metal batteries caused by Joule heating, highlighting its inevitability and potential impacts on efficiency and operation, with implications for larger-scale energy storage systems.

Contribution

It provides a numerical analysis of convection phenomena in liquid metal batteries, emphasizing their unavoidable presence and potential effects on battery performance.

Findings

Convection caused by Joule heating is unavoidable in larger batteries.

Convection intensity increases with battery size.

Flow can both enhance mixing and disrupt operation.

Abstract

Generation of thermal convection flow in the liquid metal battery, a device recently proposed as a promising solution for the problem of the short-term energy storage, is analyzed using a numerical model. It is found that convection caused by Joule heating of electrolyte during charging or discharging is virtually unavoidable. It exists in laboratory prototypes larger than a few cm in size and should become much stronger in larger-scale batteries. The phenomenon needs further investigation in view of its positive (enhanced mixing of reactants) and negative (loss of efficiency and possible disruption of operation due to the flow-induced deformation of the electrolyte layer) effects.