MANN+HUMMEL is selectively working to develop solutions for future products connected to low-emission mobility. A newly developed coolant particle filter and a coolant dryer cartridge for the oil-cooled battery of the fully electric FF91 from Faraday Future are the latest examples. Both products offer high performance and extend the service life of the batteries.

When it comes to electric mobility, extending the range is the name of the game. The success of an electric vehicle with customers largely depends on the driving range of the vehicle. The US American start-up Faraday Future is therefore relying on high voltage batteries for its first vehicle in series production, the FF91. The energy density can be increased to achieve a range up to respectively 600 kilometers according to the EPA standard or 700 kilometers according to the NEFZ standard.

 

"The core of battery electric vehicles is the battery. We need to ensure that the system is performing at its best under all conditions."

Mirco Schön, Key Account Manager Electric Mobility

 

However, thermal management and cooling is required for the batteries to achieve this performance. A particularly efficient type of cooling is possible by directing a flow of non-conductive cooling oil around the individual battery cells. The challenge here is to keep the oil clean. This is because deposits in the fine channels of the cooling system can cause irreversible damage to the channels and therefore also the battery system. This can lead to a decrease in performance or even battery failure. The same risk is present with free water which can occur at low ambient temperatures.

A systematic approach

It is impossible to prevent harmful particles and water penetrating the coolant circuit. This is because of initial dirt from the production process and elastomer wear. The coolant expansion tank, however, represents a further potential entry point for particles or water. It serves to compensate for changes in the volume of cooling oil caused by temperature fluctuations. The system has to be open in order to function and therefore it is not reliably protected against dirt and water. As it only takes a few blocked cooling channels to significantly reduce performance, better protection and the removal of water is decisive to improve efficiency. Such measures improve battery performance.

MANN+HUMMEL with its extensive experience in the filtration and separation of liquids has now for the first time developed a particle filter and a dryer cartridge for the cooling system of the high voltage batteries of Faraday Future. The spin-on filter designed by MANN+HUMMEL uses the specially developed MULTIGRADE eM-CO filter media. This media is fully synthetic, free of fiberglass and highly resistant to chemicals. MULTIGRADE eM-CO 180.1 separates 99.5 percent of particles greater than 180 micrometers while minimizing pressure drop. A drainage grid maintains the ideal spacing of the pleats. The modular interface of the metal housing can easily be adapted to meet the requirements of the respective customer to enable the particle filter to be used for various different applications.

 

The coolant dryer cartridge with its highly efficient adsorbent material allows the coolant system to remove even the smallest volume of undesired water and therefore constantly maintains the high oil quality. As a result, there are no more risks to the battery system caused by icing or corrosion. In addition, the risk of short circuits through the loss of the insulating characteristics of the oil is removed. The adsorber and the cartridge material are resistant to cold and aggressive oils. The installation in the coolant tank was realized using a screw-in unit which simplifies servicing. When the cartridge is replaced within the prescribed service interval, the oil can be used over the complete driving cycle even if there is an ingress of a large amount of water as the coolant dryer cartridge reliably adsorbs the water. A water sensor is available as an option in order to detect the water content of the oil.

 

The combination of the coolant particle filter and coolant dryer cartridge allows MANN+HUMMEL to protect oil-cooled high voltage battery systems against dirt and water. Against the background of electric mobility, the expertise to make this possible is literally being driven forward. This is because vehicles with a greater driving radius are making more progress. This is true for hybrid, fuel cell and battery‑powered electric drives.