  Liquid Metal Batteries (LMBs) are a promising concept for cheap electrical
energy storage at grid level. These are built as a stable density
stratification of three liquid layers, with two liquid metals separated by a
molten salt. In order to ensure a safe and efficient operation, the
understanding of transport phenomena in LMBs is essential. With this motivation
we study thermal convection induced by internal heat generation. We consider
the electrochemical nature of the cell in order to define the heat balance and
the operating parameters. Moreover we develop a simple 1D heat conduction model
as wellas a fully 3D thermo-fluid dynamics model. The latter is implemented in
the CFD library OpenFOAM, extending the volume of fluid solver, and validated
against a pseudo-spectral code. Both models are used to study a rectangular
10x10 cm Li||Bi LMB cell at three different states of charge.
