Volume 41: Energy Transitions toward Carbon Neutrality: Part IV

Enhancing the Discharge Performance of Liquid Metal Batteries through External Magnetic Fields Xianbo Zhou, Kai Jiang, Kangli Wang

Abstract

Liquid metal batteries are considered a competitive alternative for grid-level stationary energy storage. In this study, we investigated the effects of external magnetic fields on the charge and discharge performance of this all-liquid battery composed of three layers of fluids. Experimental results indicate that, at the current density of 500 mA cm-2, the application of a 100 mT magnetic field increases the discharge voltage by 34.64% compared to the case without a magnetic field. At a higher current density of 1000 mA cm-2, applying a 50 mT magnetic field results in a 74.5% increase in discharge voltage, demonstrating significant effects. Furthermore, we develop a numerical model using a multiphysics simulation software to uncover the underlying mechanisms. The Lorentz force generated by the interaction of the external magnetic field and discharge current induces a swirling flow in the phi direction. At sufficiently high flow velocities, turbulent flow with a notable |z| direction component is formed, assisting the transport of Li atoms in the positive electrode, reducing concentration polarization, and thereby enhancing the discharge voltage.

Keywords liquid metal battery, external magnetic field, turbulence, concentration polarization, discharge voltage