The traction battery is the core of an Electric Vehicle. In all circumstances, it is essential to protect its high-voltage components from moisture and dirt, even in long-term operation. At the same time, it must be possible to open battery housings for maintenance. That’s why automakers are turning to housings with a large cover that allows good access to all components. But the cross-section and dimensions of such seals must be adapted exactly to a specific battery. Changes are impossible without fabricating a new tool. As a result, straight sealing profiles come into use for very small production runs, such as the manufacture of prototypes.
With the "Profile-to-Gasket," or "P2G," concept, a solution meeting these needs has recently become available. Lithium-ion batteries equipped in this way have proven themselves in the Renault Zoe EV. This housing seal is based on a simple principle. The two basic functions of "sealing" and "fixing" are achieved in separate parts of the sealing profile. In this way, a compressible hollow profile on the outer side of the seal, which can be up to 15 mm wide, ensures that no fluids or particles penetrate into the housing. This hollow profile also guarantees the tolerance compensation required in a housing seal. On the inner side, there is a fixation strip that can attach the seal to the housing. The design makes it possible to manufacture the P2G seal as an endless band and trim it to the required length in each case. With targeted incisions in the attachment area, it is possible to guide the seal in tight radii around corners. Both concave and convex radii can be achieved. This solution can cover any given geometry.
Another advantage of the endless profile is that it can securely seal even very large battery housings – an important feature in view of the trend toward greater ranges. The hollow profile promotes this characteristic. By screwing down the housing and cover, the profile is compressed to a height of about 1.5 mm, whereby the fixation strips function as an end block while balancing out potential production tolerances. The low tensile stresses that emerge in the installed state ensure a high degree of mechanical tightness even during the housing’s torsions during driving.
• Prevents penetration of fluid particle in the housing
• Adaptable for any geometry of the battery
• Seal very large batteries
• Provides high mechanical strength during driving