Thermal Interface Selection Criteria for Prismatic Battery Modules
Optimal prismatic module thermal interface selection balances bulk conductivity against rheology and compliance to accommodate swelling without dielectric rupture.
Aluminum Prismatic Can
Meaning
Protective metal enclosures of rectangular shape house the electrode assemblies of lithium-ion cells to provide mechanical stability and high volumetric energy density. The aluminum prismatic can represents the standard housing choice for medium and large-format cells used in electric vehicles and stationary energy storage. This rigid enclosure protects internal layers from physical damage and prevents the ingress of moisture or air.
It also accommodates swell forces generated during cell cycling.
Structural Integrity
Sustaining internal cell pressure requires a robust wall design that prevents excessive bulging of the flat surfaces during lithiation. An aluminum prismatic can typically utilizes reinforced side walls or external module plates to manage this expansion. Excessive deformation can cause delamination of the electrode layers, which increases internal resistance and accelerates cell degradation.
Safety vents are integrated into the lid to release gas safely if internal pressure rises beyond a critical limit.
Thermal Path
Dissipation of heat occurs efficiently through the highly conductive metal walls of the container. Aluminum acts as a low-resistance path, allowing thermal energy to flow from the electrodes to external cooling plates. This cooling path keeps the cell within its optimal temperature window during cycling.
Manufacturing Process
Deep drawing represents the primary fabrication method used to form these deep, thin-walled rectangular containers from sheet metal. This process uses progressive dies to stretch the aluminum alloy into its final shape without tearing the metal. Wall thickness is kept minimal to maximize active material volume while retaining sufficient mechanical strength.
After forming, the can undergoes cleaning and surface treatment to remove drawing lubricants before electrode insertion and laser welding of the cover.