Lightweight aluminium Cold Plates can be custom-sized to match the selected cells and the liquid flow path customised for optimum cooling of the cell’s hot spots.

 

Inter-leaved system for the cooling of pouch cells.

Coolant is targeted at the cell hot spots between the terminals.

Coolant is fed from and returned to the cooler by tubes and distributed within the Module by manifold runners.

 

 

 

Inter-leaved system for the cooling of prismatic cells.

Coolant is targeted at the cell hot spots between the terminals.

Coolant is fed from and returned to the cooler by tubes.

 

 

System designed for cooling LTO cylindrical cells. Cells are inter-leaved with cold plates and coolant is targeted at the hot spot between the terminals. System inter-connection is via tubes.

 

 

 

Cylindrical cell cooling solution. The cell’s hot spot is in direct contact with the cold plate.

Columbia Staver Ltd have designed a cold plate that can significantly reduce the delta T between individual battery cells. The Isothermal cold plate has the inlet and outlet on the same end of the plate. The inlet and outlet connectors can be customer specified and can be in line with or at 90° to the manifold.

The flow path within the plate is through a custom extrusion designed to the customer’s specified width and length. This design can be customised to enable the Cold Plate to become the central component in a complex battery pack assembly.

The internal geometry within the manifold controls the flow of coolant into the channels of the extrusion. When analysed by advanced CFD the standard geometry offers very good isothermalisation. However, customers have different design requirements and cooling challenges.

Using the CFD software the geometry within the manifold can be adjusted and this subtly changes the pressure distribution and hence the balance of the liquid flowing down specific channels within the extrusion.

Shown in the images below is an example, the image on the left shows the results with the standard internal geometry. After running the CFD optimisation program 15% of the cells showed an improvement of 1°c and 75% of the cells improved by 0.5°C. This improvement can be seen in the image on the right.

Production

These Isothermal cold plates have been designed for high volume production, that’s why the flow path is a custom designed extrusion. Columbia-Staver recognise that in the early stages of a project where small volumes of prototypes might be required, paying for a custom extrusion tool might prove to be prohibitive.

Columbia-Staver can manufacture by CNC machining and brazing a flow path that will exactly replicate the form fit and function of the extruded part:

In applications where weight and space are at a premium, Columbia-Staver can offer the ideal solution. The stamped and bonded plate is made from two layers of very thin (typically 0.8mm) aluminium. The flow path is designed and then printed onto one of these layers and the layers are placed together. The plates then go through a heating and pressing process that diffusion bonds the two plates together. The printed flow path is then expanded using high pressure air to form a bubble.
These plates can be small to cool individual pouch cells or large to enable cylindrical or prismatic cells to be cooled.

 

 

In order to prevent the two layers from ballooning, dimples connect the top and bottom layers. These dimples also create turbulence in the coolant flow enhancing thermal performance.

 

 

 

The flow path can be optimised to achieve the desired thermal performance.

 

Columbia-Staver have developed the epoxy bonded multilayer cold plate.
This technology is ideal for prototypes and small production runs as no tooling investment is required.
The middle layer forms the flow path and can be customised so that the cold plate can mimic:

• Bubble plates
• Friction stir welded plates
• Serpentine plates
• Parallel flow extruded plates

 

Finished Cold plate with the three layers Epoxy bonded together and connector blocks fitted with “O” ring sealing

 

 

Image of Cold Plate with the upper layer made transparent. This shows the flow path, in this case designed to perform like a Bubble Plate

 

 

 

Exploded image showing the three individual layers, connector blocks and fixing screws

 

 

 

Three plane Cold Plate