As EV battery designs continue to explore new pack shapes, Freudenberg Sealing Technologies has developed a new, flexible busbar sealing technology that enables media-tight over-molding and works with rectangular and round busbars. The company is displaying the new sealant alongside new DIAvent components and a few other new-ish products at The Battery Show, taking place October 6-9 in Detroit, Michigan, highlighting the company’s commitment to developing new technologies for high-performance EVs.
Freudenberg designed its new sealant to protect electronics from oil coolant leakage in both low- and high-voltage applications, and to withstand temperatures between -40 and +200°C (-40 and +392°F). It’s also more leak-resistant and easier to assemble than traditional sealants.
“Even in a highly confined space with a complex geometry, we can create a tight and flexible seal,” Tania Hagel, global VP of OEM Sales for Freudenberg Sealing Technologies, told SAE Media. “In the case of mechanical stress or thermal expansion, our unique mix of chemicals and materials provides for the chemical adhesion. We’re putting together elastomers to metal and plastic to prevent any micro-cracks or leaks.”
Freudenberg’s new busbar sealant is available now.
Freudenberg also displayed two new versions of its DIAvent pressure equalization element for high-energy-density battery systems. The new DIAvent maxFlow unit has a reversible, open degassing vent that provides a full degassing rate near the opening pressure threshold, the company said, along with an activation level that can be adjusted between 50 and 200 mbar (0.725 and 2.90 psi). The DIAvent Hybrid unit offers an emergency degassing ability along with permanent bidirectional pressure equalization.
“The Hybrid integrates an aluminum cover and has a lightweight body,” Hagel said. “Not only does that help with temperature resistance – I think it was up to, like, 600 C – but it also provides for direct contact to the housing with no creeping.”
Another benefit of the new DIAvent units, Hagel said, is that they were designed with customers’ assembly lines in mind. She said Freudenberg engineers visit plants to see how things are assembled and what tools the operators are using.
“The assembly lines are already put in place, and we have to fit within that,” she said. “A lot of times, you have to fit things within a certain space and be able to activate them and put them in and assemble them in a robust manner. When we talk about the low height of the DIAvent, for example, that has to do with customer feedback on how they’re assembling the product. Because you can’t stress the operators out. We have to take that into consideration in everything we do.”
In Detroit, these new items were showcased alongside other recent Freudenberg technologies, including battery cell caps and a 3D Waveguide Antenna. The company’s advanced fluid connectors prevent leakage while being vibration-resistant.
“It’s not just sealing,” Hagel said. “It’s also centering, it’s protecting, and that’s all in one component.” The fluid connectors feature flexible membranes and have special sealing beads, “that ensure a reliable seal even when the parts are misaligned,” she said.
