Greater Safety for Lithium-ion Batteries

The Problem

Until now, there have been separate solutions for each scenario in the battery housing. Both had their weak points. During normal operation, a porous PTFE film handles the pressure equalization. But it is sensitive to mechanical influences. In addition, particles and fluid media can contaminate the film, which impairs its permeability and thus the battery’s “respiration.” Emergency degassing employs a rupture disc in the housing. It bursts open automatically under extreme pressures. The housing then remains open, potentially leading to the creation of a flammable gas-air mixture.

The Solution

DIAvent® Highflow performs both functions and can be modified for attachment to any battery housing. During normal driving, “respirating” layers of nonwovens in the umbrella valve regulate the exchange of air and pressure. They also keep water and dirt out. In an emergency or accident, a sealing lip allows the escape of large quantities of gas. Its special silicone elastomer responds precisely to predetermined pressure differences. Once the gas escapes, the elastic sealing lip springs back and closes the housing. Short-term pressure peaks can also be cushioned in this way.