Freudenberg Sealing Technologies has introduced an optimized sealing material for e-mobility applications. The company said this offers an alternative to PFAS-containing thermoplastic and FKM seals. This new line of elastomer seals for EV batteries provides enhanced sealing performance, ensures battery longevity, and complies with environmental regulations. the company said.

OEMs Drive Demand for Elastomer Seals for EV Batteries

The electric vehicle market continues to expand, placing greater importance on battery life, thermal safety, and performance. OEMs in Europe and the United States now demand materials that meet stricter sustainability standards. Freudenberg said it has responded by creating elastomer seals for EV batteries that outperform thermoplastics, especially in thermal runaway scenarios.

Elastomers Maintain Shape During Stress

Thermoplastics traditionally used in battery seals have long-chain macromolecules that don’t cross-link chemically. These deform over time during charge cycles. In contrast, elastomers contain cross-linked chains, allowing them to respond elastically and maintain their form despite temperature-driven expansion and contraction.

“Our O-rings made from the new elastomer therefore prevent electrolyte from leaking out of the battery cell or impurities from entering the cell,” explained David Kuhne, Application Engineer at Freudenberg Sealing Technologies. “You shouldn’t think of a battery cell as a rigid construct – it ‘breathes’. When the temperature in the battery cell rises from ambient levels to – as a rule – ranges of up to 60°C, the cell expands and then contracts in the same way as it cools. Elastomers show significant advantages over thermoplastics during this continuous stress.”

Materials and Manufacturing Boost Efficiency

Freudenberg said it designed this sealing material with sustainability and efficiency in mind. Customers testing the new elastomer reported a tenfold improvement in leakage rates over conventional seals. The company also improved its process engineering to support high-volume production, it said.

“Premature capacity loss, which has been observed in cells sealed with conventional elastomers, can result from minimal but still present impurities in the sealing material,” said Dr. Stefan Schneider, Head of Material Development. “The infiltration of moisture into the cell has a similar effect. It can cause the decomposition of electrolyte components. These aspects were considered when the new material was developed.”