Magneto-hydrodynamic stability of a liquid metal battery in discharge

Abstract

All liquid three layer batteries are intended as large scale electrical energy storage. The paper investigates long wave interfacial instabilities driven by the electromagnetic forces during dynamic phases of the battery charging/discharging. The liquid metal battery of 20 cm size with sodium metal anode, which is a candidate for experimental and commercial implementation, is shown to be unstable at the discharge state when the top metal layer depth is reduced below a critical level. The numerical model includes the effects of viscous friction and the horizontal wave velocities. The instability does not depend on the initial interface perturbation type.