Configuring a Stacked Cell

Defining the Dimensions of a Stacked Cell

The cell dimensions are specified in Simcenter Battery Design Studio within the battery cell definition. For a stacked configuration, the battery cell imported into Simcenter STAR-CCM+ includes the positive and negative electrodes and tabs, and also the separators.

More information on the parameters that Simcenter STAR-CCM+ uses is given below. Other cell components, such as packaging and busbars, are not imported into Simcenter STAR-CCM+.

The cell dimensions depend on the following attributes:

To see a summary of the values that are used to define the cell size, select the Report node in the battery window. The cell dimensions are in the Stack Properties section.

Electrode Height and Width

You can define the electrode size in the battery window. In the left panel, select the appropriate node, + Electrode or - Electrode. Then, in the right-side of the window, enter the appropriate height and width values for the electrode.

When you set the electrode sizes, ensure that the width of the negative tab is larger than the width of the positive tab.

Tab Height, Width, and Offset Values

You can also define the tab dimensions in the + Electrode or - Electrode node. You can specify the tab height and width, and also define the offset of the tab from the left edge of the electrode.

The tab offset values are specified from the edge of each electrode individually. Since the negative electrode is typically wider than the positive electrode, you need to set the relative position of the electrodes in order to align the tabs correctly.

Separator Offset Values

You can define the size of the separators in the battery window. In the left panel, select the Builders > Simple node, and then select the Offsets tab.

The X and Y offset values of the Negative wrt separator property specify how far the separator layer extends from edges of the negative electrode. For example, if the negative electrode was 88 mm wide, specifying an Xoffset value of 1 mm would result in a separator layer 90 mm wide.

Relative Position of Electrodes

You can also define the relative position of electrodes in the Offsets tab of the Builders > Simple node. The Positive wrt negative setting defines the position of the positive electrode relative to the negative electrode. The relative position is defined in the X and Y offset values. These values specify the distances from the left edge of the negative electrode to the left edge of the positive electrode, and from the top edge of the negative electrode to the top edge of the positive electrode.

By default, all these values are set to 1 mm. You need to change these values if you have changed the width or height of the electrodes, or if you want to define wider or narrower separators.

Electrode Thickness

To review the total thickness of each electrode, select the + Electrode > Formulation node, or the - Electrode > Formulation node. The total thickness is displayed under the Computed Electrode Properties, next to Thickness (w/collector). This value includes the thickness of the collector and coating for a single electrode.

Separator Thickness

You can define the thickness of the separators in the battery window. To set the separator thickness, select the Separator node. In the table, modify the appropriate values in the Thickness column.

Number of Electrodes in Stack

You can define the number of electrode layers in the stack. In the battery window, select the Builders > Simple node, then select the Stack tab. The Total # of electrodes including ends box specifies the total number of electrodes in the cell.

The selected option for End Electrodes affects the values that you can specify. If you select Both Negative or Both Positive, the total number of electrodes must be odd. If you select Pos(right)/Neg, the total number of electrodes must be even.

The number of separators in the cell is equal to the (total # electrodes + 1), that is, a separator layer between adjacent electrodes and an additional separator at either end of the stack.