Battery box of the future

The use of lightweight components is becoming increasingly important for the production of vehicles. Future-oriented developments of electrically driven vehicles only achieve their efficiency goals through the consistent use of extremely lightweight materials such as aluminum. Aluminum foam combines many advantages, such as extreme lightness, ductility, recyclability and excellent absorption and conductivity, making it ideal for the automotive industry of the future.

Havel metal foam offers a product tailored to the customer. From drawing to serial production, we provide everything.

Battery housing for electric vehicles

A trend-setting development of the Havel metal foam is the battery housing for electric vehicles. Low weight, good crash behavior, high rigidity and possibilities for temperature regulation predestine these newly developed vehicle components for use in electric vehicles.

The battery case of the Havel Lite® series is made entirely of aluminum foam sandwiches. Due to the versatile properties of the foam, the product is ideally suited for use as a sheathing of batteries in the automotive industry.

Aluminum foam sandwich panels between the battery cells act as spacers and crash absorbers. The aluminum foam can also be integrated with profiles or tubes for battery cooling.

Manufacturing technologies

Direct foaming of a pipe system into the metal foam core. A metallurgical bond of the cover sheets is thus possible.

Subsequent insertion of the pipe system in the metal foam core. The cover sheets are subsequently glued to the metal foam.

Development

Current designs of electric vehicles are based on conventional combustion engine vehicles, but contain the safety-related battery technology mostly on the vehicle underbody. Protecting the battery modules is therefore a very high priority. Protecting the battery system from a damaging collision from below requires new solutions and extensive testing. One of these new solutions is the protection of the battery cells by aluminum foam sandwiches with aluminum cover layers (AAS).

Tests

The EVERSAFE project simulated underbody impact in which a vehicle weighing 943 kg and traveling at 40 km / h crossed a semicircular obstacle whose highest point was higher than the lowest battery case point. As a result of overrunning, it comes to the impact load on the housing.

Heat exchange

When using lithium-ion batteries in electric vehicles, three main aspects have to be considered from a thermal point of view:

At temperatures below 0 ° C, the performance of the battery and thus the range drops significantly.

At temperatures above 30 ° C the aging of the battery increases strongly.

At temperatures above 40 ° C irreversible damage to the battery may occur.

The thermal effects on a battery, such as self-heat, due to the internal battery resistance, outside temperature and heat losses, must therefore be controlled and regulated by heating or cooling.

Thermal management

Using the manufacturing technologies we apply, it is possible to integrate pipes and profiles into the metal foam, thus taking advantage of the good thermal conductivity of the aluminum. Depending on the overall thickness of the aluminum foam core, the internal cavities created can be used to lay additional conduits for flowing media used for cooling or heating of the battery cells installed in the housing.

Construction

The dimensions of the battery case correspond to the specifications of the customer. The bottom plate is designed as a continuous sandwich-plate. This is to ensure the requirement for tightness. The production of the housing walls can be integral or differential.

Integral production

The housing walls are produced by wedge-shaped or rectangular recesses. Advantages of this variant are the reduction of the joints and the imperviousness due to a closed outer cover layer.

Differential manufacturing

In the differential production, the housing is made of a plurality of individual components, which are joined together by welding or gluing.

Friedrich Schuller