Battery Layers
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 node is available with a Battery Design Module license only.
The effective In-layer (kil) and Through-layer thermal conductivities (ktl), Density and Heat capacity values are specified by the user.
The homogenization of the heat equation (for solids) is performed by the use of anisotropic thermal conductivity tensors, which are defined based on the configuration (cylindrical or pouch) of the battery layers, and the effective thermal conductivity in the in-layer and through-layer directions.
The Layer configuration setting specifies how to calculate the conductivity tensor and what coordinate system to use 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) can 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
,
,
or
,
respectively.
For cylindrical batteries, the layers are typically wound around a cylindrical axis, and can be approximated by defining the anisotropic transport properties in a cylindrical coordinate system.
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 is defined in the (rc, ϕc, zc) system as
.
The Flat-sided oval (prismatic) configuration activates one Semicylinder Selection child node and one Rectangular Block Selection child node. The thermal conductivity tensor is defined in cylindrical coordinates for the Semicylinder Selection and in Cartesian coordinates for the Rectangular Block selection, as described above for the Spirally wound (cylindrical) and Flat parallel (pouch) configuration, respectively.
Figure 6-1: A typical jellyroll geometry applicable for the flat-sided oval (prismatic) option, including two semi-cylinder (dark grey) and one rectangular block (light grey) domains.
Coordinate System Selection
The settings of this section are locked and cannot be altered by the user.
Multicylindrical coordinate systems, supporting multiple disjoint domains, are created automatically and selected when Spirally wound (cylindrical) is selected as Layer configuration in the Battery Layers section. For the Flat-sided oval (prismatic) configuration, a multicylindrical coordinate system is selected for the Semicylinder Selection child node.
•
Rectangular Block Selection
•
Semicylinder Selection
Cooling of a Prismatic Battery: Application Library path Battery_Design_Module/Thermal_Management/prismatic_battery_cooling
Liquid-Cooled Prismatic Battery Pack: Application Library path Battery_Design_Module/Thermal_Management/prismatic_battery_pack_cooling
Location in User Interface
Context Menus
Heat Transfer in Solids and Fluids > Specific Media > Battery Layers
Heat Transfer in Solids > Specific Media > Battery Layers
Heat Transfer in Fluids > Specific Media > Battery Layers
Heat Transfer in Porous Media > Specific Media > Battery Layers
Ribbon
Physics tab with Heat Transfer in Solids and Fluids, Heat Transfer in Solids, Heat Transfer in Fluids, or Heat Transfer in Porous Media selected:
Domains > Specific Media > Battery Layers