Battery packs and modules sealing
Battery modules are indispensable in automotive applications such as electric vehicles. EVs are developing fast and are becoming part of our daily lives. Whether it is your municipal bus running on electricity, the truck silently delivering your products, or your neighbor’s bicycle or scooter moving almost as fast as a car : batteries are everywhere, often without us even noticing.But what exactly is a battery pack?
A battery pack is designed to store energy and release it later as a source of electricity. It is the core element that enables electrification across multiple industries, from mobility to renewable energy storage.
A battery pack is composed of modules, which themselves are assemblies of multiple cells : cylindrical, prismatic, or pouch cells. When combined, these cells form a battery module. Several modules are then integrated into a battery pack, along with a housing (case), electronic management systems (BMS), and thermal management components.
To optimize weight, durability, and performance, modern battery packs increasingly rely on adhesive bonding instead of traditional fastening methods like bolts or screws. This approach reduces weight, distributes mechanical stress more evenly, and minimizes vibrations throughout the system.
Adhesives and resins are therefore critical materials inside a battery pack. Beyond their use within the cells themselves (for example, sealing the electrolyte), they play several key roles at the pack level.
1. Battey case sealing
The battery pack enclosure plays a critical role in ensuring the safety and durability of the entire system. It must remain perfectly sealed throughout its lifetime, despite exposure to demanding environmental and operating conditions. It must be perfectly sealed to operate safely in real-world conditions. Adhesives and sealants are used to create a reliable barrier against external elements such as moisture, dust, and chemicals. In automotive applications, the sealing system must withstand water ingress, temperature fluctuations, and continuous vibrations.
This ensures long-term reliability and safety, even in harsh environments (rain, road conditions, temperature variations).
2. TIM : Thermal Interface Material
Thermal management is one of the most critical aspects of battery pack design. Lithium-ion cells generate heat during operation, and excessive temperature or uneven heat distribution can negatively impact performance, lifetime, and safety. Thermal Interface Materials (TIMs) are used between battery modules, cooling plates, and the enclosure to optimize heat transfer. Their primary function is to fill microscopic air gaps between surfaces, replacing insulating air with a thermally conductive material.
By maintaining a uniform temperature across the battery pack, TIMs help prevent hot spots, improve energy efficiency, and reduce the risk of thermal runaway. As a result, they are essential for both performance optimization and system safety.
3. Potting and encapsulation
Electronic components within a battery pack, such as the Battery Management System (BMS), require robust protection to ensure reliable operation over time. These components are particularly sensitive to environmental exposure, electrical stress, and mechanical vibrations.
Potting and encapsulation involve covering or embedding electronic assemblies in protective resins. This process provides electrical insulation, preventing short circuits and ensuring safe operation in high-voltage environments. It also protects components from moisture, dust, and chemical exposure. In addition, potting materials help absorb mechanical stresses caused by shocks and vibrations, which are common in automotive and industrial applications.
Overall, potting and encapsulation significantly enhance the durability and reliability of battery electronics, reducing the risk of failure and extending the lifetime of the system.
- Tin free, siloxane free
- Paintable sealant
- Heat and cold resistance
- ATF and oils resistance
- Heat conductive (2,0 W/m.K)
- TIM : Thermal Interface Material
- Fixing of components mounted on substrates
- Strong adhesion to a wide range of materials
- After curing, it becomes a rubber-like strong elastic material. It has significantly higher strength and elongation than other elastic adhesives
- The pot life (gel time) after mixing of the two components is relatively long, thereby allowing sufficient time for application
- The curing time can be shortened by heating after bonding, so the curing speed can be controlled according to the situation
