# Numerical simulation of rolling pad instability in cuboid liquid metal batteries

## TL;DR

This paper uses numerical simulations to analyze the rolling pad instability in liquid metal batteries, revealing how density differences influence stability and wave behavior, which is crucial for large-scale energy storage applications.

## Contribution

It provides a detailed numerical analysis of the electromagnetic interfacial wave dynamics in liquid metal batteries, highlighting the impact of density ratios on stability and wave coupling.

## Key findings

- Density ratio determines stability and wave type.
- Instability significantly affects battery operation.
- Simulation confirms earlier theoretical conclusions.

## Abstract

The rolling pad instability is caused by electromagnetic interactions in systems of horizontal layers with strongly different electric conductivities. We analyze the instability for a simplified model of a liquid metal battery (LMB), a promising device for large-scale stationary energy storage. Numerical simulations of the flow and the dynamics of electromagnetically coupled interfacial waves are performed using OpenFOAM. The work confirms the earlier conclusions that the instability is a significant factor affecting battery's operation. The critical role played by the ratio between the density differences across the two interfaces is elucidated. It is found that the ratio determines the stability characteristics and the type (symmetrically or antisymmetrically coupled) of dominant interfacial waves.