Freudenberg’s new DIAvent maxFlow vents over 190 liters per second in EV battery thermal runaway events

Freudenberg Sealing Technologies has introduced the DIAvent maxFlow, a cutting-edge thermal runaway vent designed specifically for lithium-ion vehicle batteries. This new degassing element significantly improves safety by delivering over 190 litres per second at 300 mbar differential pressure, which is 2.5 times the flow rate of its predecessor, the DIAvent HighFlow. The innovation lies in its use of a profiled metal spring instead of the traditional rubber umbrella, enabling the valve to snap open instantly when a critical pressure threshold is reached, thereby expelling hot gases more rapidly and reducing the risk of thermal events spreading across battery cells. The design of the DIAvent maxFlow also offers enhanced operational precision and reliability. Its trigger pressure can be finely adjusted between 50 and 200 mbar with minimal tolerance, outperforming conventional burst disks that lack such accuracy and cannot reclose once activated. Unlike burst disks, the maxFlow valve’s reversible mechanism allows for non-destructive end-of-line testing of fully assembled battery packs, providing a significant quality control benefit during production. This feature ensures that the valve remains functional and intact, improving overall manufacturing efficiency and safety assurance. In addition to its performance advantages, the DIAvent maxFlow boasts a compact and robust construction. Measuring 86 by 86 millimetres with a slim 12.1-millimetre installation height, the valve meets stringent protection standards including IPX9K and IP6KX, and carries UL94 V0 flame-retardancy certification. It is designed for flexible mounting options, including standard M6 bolts, clips, and bayonet fittings, and incorporates an integrated PIP seal to accommodate minor housing unevenness. These specifications underline Freudenberg’s commitment to delivering a reliable, easy-to-install solution that enhances battery safety. Daniel Uhl, Head of Product Management at Freudenberg Sealing Technologies, emphasised that the DIAvent maxFlow addresses the shortcomings of previous venting solutions within a single product. By combining rapid response, precise triggering, and the ability to reseal and be tested non-destructively, the valve represents a significant advancement in battery safety technology. As electric vehicle adoption continues to grow, innovations like the DIAvent maxFlow will be critical in mitigating the risks associated with thermal runaway events and improving the overall resilience of battery systems.