Freudenberg develops elastomer-based battery cell cap technology

Weinheim, Germany – Freudenberg Sealing Technologies (FST) has developed a new generation of battery cell caps that uses liquid elastomers to integrate terminals directly into the cell cap structure for prismatic and cylindrical battery cells.

In a 3 June statement, the company said the technology, called Cell Caps 2, is designed to reduce component count while improving gas tightness, mechanical robustness and electrical insulation.

According to Freudenberg, liquid elastomer is injected into the gap between the battery poles and the cell cap base plate, creating a permanent bond between the components.

The elastomer “permanently bonds” the components together, providing “excellent gas tightness, mechanical robustness, and electrical insulation – all with a minimal number of parts and very low mass,” said FST.

This, it noted, can significantly reduce the overall battery weight.

In addition to being less complex and more compact, Generation 2 technology can reduce the height of the cell cap by up to 30%, depending on customer requirements.

This advantage, explained FST, directly translates into higher energy capacity and, consequently, a longer operating time.

The development comes as the German manufacturer is ramping up its series production of the ‘Cell Caps Generation 1.’

FST said it is currently working on the mass production of “a round cell cap that fully leverages all the advantages of the next generation technology.”

In this context, the manufacturing process for these small components plays a particularly crucial role in optimising production costs.

The cell caps can be manufactured using the same technology as valve stem seals, which Freudenberg produces in the millions with high quality.

Alongside the cell cap development, the company announced expanded versions of its cell-to-cell thermal barriers and venting foam mats for battery applications.

FST is presenting the technologies at Battery Show Europe, taking place in Stuttgart, Germany 9-11 June.