Datwyler: EPDM challenging fluoroelastomers in EV sealing

Altdorf, Switzerland – Datwyler has reported some new materials-selection trends around the development of advanced sealing products that enhance the safety and performance of EV batteries.

These products, it noted, require high-performance elastomers that provide superior resistance to chemicals, temperature extremes, and mechanical stresses for various battery configurations.

Compounds must be thoroughly screened and tested for their ability to be in contact with corrosive electrolytes, and identify any possible ‘leachables’ that might impact the cell’s electrochemistry.

For battery-cell sealing, Datwyler said its latest portfolio includes high-performance elastomers like FKM (fluoroelastomer) and EPDM, each optimised for different operating conditions.

Currently, it said, the most popular sealing solutions for cell seals are “FKM and certain thermoplastics”, as they offer high thermal resistance and chemical stability.

However, according to Datwyler, many customers are now trying to replace FKM and thermoplastics with EPDM due to cost savings and potential PFAS regulations.

EPDM solutions developed by Datwyler experts offer “a cost-effective alternative with good resistance to weathering, ozone, and a wide range of temperatures,” the Swiss group stated.

While not matching the heat resistance of FKM, EPDM provides “sufficient performance” for many applications and is even better for contact with electrolytes in terms of swelling, continued Datwyler.

Concluded its report: “High-performance sealing materials like FKM and EPDM contribute to the prevention of leaks and contamination, which can cause battery failure or safety hazards.

“Balancing performance and cost with the appropriate material selection ensures competitive advantage and customer satisfaction.”