How to circumvent the size limitation of liquid metal batteries due to the Tayler instability

Highlights: → Liquid metal batteries could store large amounts of electricity. → The Tayler instability is a serious obstacle for the scale-up of those batteries. → It can be avoided by a return current through an insulated central hole. → This would allow the scale-up of liquid metal batteries to arbitrary sizes. - Abstract: Recently, a new type of battery has been proposed that relies on the principle of self-assembling of a liquid metalloid positive electrode, a liquid electrolyte, and a liquid metal negative electrode. While this configuration has been claimed to allow arbitrary up-scaling, there is a size limitation of such a system due to a current-driven kink-type instability that is known as the Tayler instability. We characterize this instability in large-scale self-assembled liquid metal batteries and discuss various technical means how it can be avoided.