The Battery Layers domain node, available in 3D, allows for modeling of heat transfer in battery layers cells using a homogenized approach, where the individual layers of the cell do not need to be resolved in the computational mesh.

The effective In-layer (kil) and Through-layer thermal conductivities (ktl), Density and Heat capacity values are specified by the user.

The Layer configuration setting specifies how the conductivity tensor should be calculated, and what coordinate system should be used for defining the heat equation. If the layers are oriented in a Flat parallel (pouch) configuration, the thermal conductivity tensor is defined using the default global cartesian coordinates (x, y, z). This would be the typical configuration for a pouch cell.

The Through-layer direction (plane normal) may be set to coincide with either the x, y, or z coordinate axis, and the tensor is then defined in the (x, y, z) system as either

For a Spirally wound (cylindrical) configuration, the thermal conductivity tensor is defined using the cylindrical coordinates (rc, ϕc, zc) with the origin placed in the center of each battery cylinder, and the zc-axis pointing along the Longitudinal axis of the cylinders, which is specified by the user to coincide with either the x-, y-, or z-axis.

The thermal conductivity tensor then defined in the (rc, ϕc, zc) system as

Multicylindrical coordinate systems, supporting multiple disjoint domains, are created automatically when Spirally wound (cylindrical) is selected as Layer configuration in the Battery Layers section.

Physics tab with Heat Transfer in Solids and Fluids, Heat Transfer in Solids, Heat Transfer in Fluids, or Heat Transfer in Porous Media selected: