Thermal adhesives in lithium-ion battery packs

Thermal adhesives - Thermal management in lithium-ion battery packs

Thermal adhesives play a crucial role in lithium-ion battery packs, especially in electric vehicles (EVs), by facilitating efficient heat dissipation and maintaining optimal operating temperatures. Here's a breakdown of their applications in lithium cell connections.

1. Cell-to-Cell Bonding:

• Heat Dissipation: Lithium-ion cells generate heat during operation due to internal resistance. Thermal adhesives between cells create a thermally conductive pathway, allowing heat to spread evenly and dissipate more effectively. This prevents localized hot spots that can accelerate battery degradation and compromise safety.

• Structural Support: Adhesives provide mechanical bonding between cells, enhancing the structural integrity of the battery pack. This is particularly important in cell-to-pack designs where individual cells are directly integrated into the battery pack structure.

• Electrical Insulation: While primarily designed for thermal conductivity, these adhesives offer electrical insulation, preventing short circuits between adjacent cells.

2. Cell-to-Cooling Plate Bonding:

• Efficient Heat Transfer: Thermal adhesives bond cells to cooling plates or heat sinks, which are essential components of the battery thermal management system. The adhesive facilitates efficient heat transfer from the cells to the cooling system, maintaining optimal operating temperatures.

• Uniform Contact: The adhesive ensures uniform contact between the cell and the cooling plate, maximizing the heat transfer area and efficiency.

3. Module-to-Pack Bonding:

• Thermal Management at the Module Level: Battery packs with modular designs, and thermal adhesives are used to bond individual modules to the pack structure. This helps manage heat dissipation at the module level, further enhancing overall thermal management.

• Structural Integrity: Adhesives contribute to the structural integrity of the battery pack by bonding modules together and to the pack housing.

Key Considerations for Thermal Adhesives:

• Thermal Conductivity: The primary requirement is high thermal conductivity to ensure efficient heat transfer.

• Adhesion Strength: The adhesive provides strong bonding to maintain contact between components under various operating conditions.

• Electrical Insulation: The adhesive should be electrically insulating to prevent short circuits.

• Chemical Compatibility: The adhesive must be chemically compatible with the cell materials and other components in the battery pack.

• Long-Term Reliability: The adhesive must maintain its properties over a wide temperature range and throughout the battery's lifespan.

In conclusion, thermal adhesives are essential for effective thermal management in lithium-ion battery packs. They facilitate heat dissipation, enhance structural integrity, and contribute to the overall safety and performance of the battery system.