Heat is a concern for battery packs; it can reduce the battery charge rate, resulting in increased charging time, and can even lead to damage of temperature-sensitive batteries. Today, auto OEMs are looking for effective thermal management designs as they compete for longer range EVs.
Battery pack manufacturers realize that sometimes, an ordinary gap filler or thermal pad won’t meet the high bond strength requirement of their design. If a part needs to be secured to a cooling attachment, chances are thermal conductivity will be an issue. To meet this need, thermally conductive adhesives are key as they solve both the structural and thermal requirements.
Knowing this, it is important to consider the following points when searching for a structural adhesive for a battery pack:
- What are you looking to bond?
- What are the substrates that will be bonded?
- What surface treatments or cleaning is needed to achieve optimal bond strength?
- What bond strength do you need?
- Is thermal conductivity a necessity for this application?
- Is your manufacturing facility equipped to handle adhesives?
Meeting with an application engineer will help determine what material will best meet the specifications needed. Of note, typically the higher the thermal conductivity needed, the more expensive the solution may be, which is why it important to determine what is required for each situation. If the application calls for simply attaching the battery pack to an enclosure, a less expensive, non-thermally conductive structural adhesive may be the correct solution for your need. If the battery pack must endure a high vibration application, such an in an EV, then high bond strength is essential. A structural adhesive can provide the strong bond needed to ensure a batteries, modules, and pack remains securely attached.
In terms of thermal conductivity, tests have shown that reducing a battery’s temperature has a proven outcome: for every 10-degree-Celcilus reduction in temperature, it effectively doubles a battery’s life. For this reason, using a thermally conductive material is preferred to reduce battery temperatures.
The application engineer will review your product’s manufacturing process to determine what type of adhesive would be recommended for your process: both one and two-part adhesives are available. The two-part adhesives are most frequently specified, as they are significantly stronger, pass rigorous environmental testing, and are more flexible to fit your already existing processes. Also, 2K adhesives can cure rapidly at room temperature and do not require heating of battery packs which can be harmful to the finished product. Additionally, the bond achieved with the structural adhesives is considered permanent and is dispensed in a thixotropic bead that can be used for any geometry and retain its shape while completely inverted on a surface prior to assembly
The specifications for LORD Thermally Conductive Structural Adhesives showcase our high strength and conductivity: Three of our products fall into this category at 0.6-3.0 w/mK including urethanes, acrylics and epoxies. These products are available in 50 mL cartridges to 55-gallon drums.
As battery technologies evolve, the ability to manage heat during charge and discharge cycles is crucial for optimizing performance. LORD’s adhesives are fully customizable and compatible with cylindrical, pouch and prismatic battery cells. LORD application engineers are available to assist you in finding the best cost-targeted solution for your thermal management needs, helping optimize your process and improve performance. Contact us today to find the best solution for your needs.
For more information, watch this video on the use of structural adhesives to assemble electronics.