Freudenberg rolls out elastomer-based battery cell cap tech to cut weight and boost EV range

German sealing giant Freudenberg Sealing Technologies (FST) has unveiled Cell Caps 2, a next-gen battery cell cap that ditches traditional metal-and-plastic designs in favor of a liquid-elastomer injection process. The tech permanently bonds terminals directly into the cell cap structure for prismatic and cylindrical cells, slashing part counts while beefing up gas tightness, mechanical strength, and electrical insulation. FST injects liquid elastomer into the gap between battery poles and the cap base plate, creating a single-piece, ultra-light assembly that trims up to 30% off cap height—room that can be converted into extra battery capacity and longer EV range. The company is already scaling up series production of the first-gen Cell Caps and is now prepping mass production of a round-cell version that fully leverages the second-gen advantages. Freudenberg reckons the same high-volume elastomer molding process used for valve stem seals—components it already produces in the millions—will keep production costs lean. Alongside the cap breakthrough, FST rolled out expanded thermal barriers for cell-to-cell heat management and venting foam mats, all aimed at tightening EV battery safety and packaging. The new tech is on display at Battery Show Europe in Stuttgart, Germany, June 9–11.