Electromagnetically driven convection suitable for mass transfer enhancement in liquid metal batteries

The electrical potential in a battery jumps at each electrode-electrolyte interface. We present a model for computing three-dimensional current and potential distributions, which accounts for such internal voltage jumps. Within the framework of the finite volume method we discretize the Laplace and gradient operators such that they account for internal jump boundary conditions. After implementing a simple battery model in OpenFOAM we validate it using an analytical test case, and show its capabilities by simulating the current distribution and discharge curve of a Li||Bi liquid metal battery.

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“…Specifically, we would like to extend the model by convection [18,19], heat transfer [73,77] and electrode kinetics.…”

Section: Discussionmentioning

confidence: 99%

Modeling discontinuous potential distributions using the finite volume method, and application to liquid metal batteries

Weber

Landgraf

Mushtaq

et al. 2019

Electrochimica Acta

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“…4(c). The internal resistance, JH e /σ e , has a large impact on the value of E cell at t = 0 because we somewhat arbitrarily choose the large value H e ≈ 1 cm, but other values for H e can be used in (13). The piece of information that is important in Fig.…”

Section: Without Solutal Buoyancymentioning

confidence: 99%

“…[10] followed by the numerical simulations in Ref. [11][12][13] all suggest that the electrovortex mechanism combined with thermal buoyancy can yield a nonnegligible flow in the alloy, but the mixing of the alloy itself, i.e., its spatially and temporally varying composition was not considered in these references. A first attempt to model mixing in the alloy was done in Ref.…”

Section: Introductionmentioning

confidence: 99%

Solutal buoyancy and electrovortex flow in liquid metal batteries

Herreman

Bénard²,

Nore³

et al. 2020

Phys. Rev. Fluids

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Solutal buoyancy has a large impact on the flow of the alloy phase composing the positive electrode in liquid metal batteries. During discharge solutal buoyancy creates a stabilizing stratification, during charge it creates a vigorous solutal convection. In this article we provide new physical understandings of the role of solutal buoyancy during both charge and discharge. In particular we find that during discharge the electrovortex mechanism is in general not strong enough to counter the stabilizing effect of solutal buoyancy, and therefore this mechanism cannot be used to mix the alloy as is sometimes suggested in the literature. We show that the mixing capability of a generic flow in the alloy phase can be estimated by comparing the typical flow magnitude U to two velocity scales: U p and U m . Below U p the flow cannot mix the alloy, and above U m the flow significantly opposes solutal buoyancy. Although we focus on Li||Pb-based batteries, these simple mixing criteria can be used during the discharging phase in other types of liquid batteries. We also present new, fully three-dimensional simulations of solutal convection during the charging cycle. These simulations suggest scaling laws for the magnitude of the convective flow, the time for the onset of solutal convection, and the typical inhomogeneity level in the alloy during charge. We propose physical arguments to explain these scaling laws.

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“…Both types of forcing are considered simultaneously in Weber et al. (2018). That paper also studies the effects of supplying the current with a wire that is perpendicular to the axis of the battery.…”

Section: Introductionmentioning

confidence: 99%