Technology focus: Oil-exuding silicone for automotive battery seals

Wacker has developed a new oil-exuding liquid silicone rubber for sealing applications in electric vehicle battery cooling systems.

In a recent release, Wacker said the material was developed particularly for connector seals and other sealing elements used in the cooling circuits of EV traction batteries.

According to the group, the crosslinked elastomer "continuously releases silicone oil from its surface," creating a lubricating film intended to facilitate machine assembly of moulded parts.

The silicone also combines coolant resistance with a low compression set, which Wacker said helps seals maintain their performance under prolonged pressure.

In testing, samples retained most of their mechanical properties after 1,000 hours in a glycol-water mixture at 125°C, recording a compression set of 44%.

The silicone material has a Shore A hardness of 60 and can be stretched by 270% without cracking or damage, according to Wacker.

It also retains elasticity at temperatures down to -45°C.

Potential applications include weather packs as well as sealing elements for EV battery cooling circuits.