A Comparative Study of Thermally and Electromagnetically Driven Flow in the Electrolyte of Liquid Metal Batteries and Their Effects on Ion Transport

High-temperature liquid metal batteries (LMBs) are regarded as a promising candidate for grid-scale stationary energy storage. Numerical simulation is an important method to investigate physical phenomena such as fluid flow and mass transfer inside the LMB. At present, most models of the LMB electrolyte treat molten salt as a conductive fluid with a certain conductivity, while ignoring the ion distribution inside it. In this work, we develop a multi-field coupled model of LMB and comparatively analyze the thermally driven flow and electromagnetically driven flow in the molten salt electrolyte for the first time. Subsequently, we discuss the effects of flow on ion transport and electrochemical performance. Additionally, this model elucidates some experimental phenomena, such as the origin of the inhomogeneous deposition of intermetallic compounds and the reason why LMB can withstand ultra-high current densities. This work provides a deeper understanding of the internal mechanism of liquid metal batteries.