Together with RISE Department Polymer, Fiber and Composite in Sweden and Fraunhofer IWU and FiberCheck in Germany, AP&T has developed a new type of battery housing for electric cars. By combining aluminum foam and carbon fiber based sheet molding compound (C-SMC) composite in one and the same component, they have succeeded in reducing its weight and increasing its collision safety. The manufacturing itself is done in a single forming step.
Adequately protecting the heart of the car – the battery pack – is a vital target for all electric car manufacturers. At the same time, efforts are always being made to reduce the weight. So, what’s the optimal solution?
“Today, battery housings can be manufactured using steel, aluminum, SMC materials, or even a combination of multiple materials to meet requirements for cost, lightweight design, and safety,” explains Dr. Michael Machhammer, Manager of Development for Forming Processes & Tooling at AP&T.
The collaboration parties’ solution combines many of the features that car manufacturers demand. Compared to the sheet metal battery housing that was used as a reference, they have achieved an 18% weight reduction. Simulation results has also shown significantly improved collision safety. During side impacts, the side pole simulation results showed 75% less material deformation, and in the bollard test simulation (impact from below), there was an improvement of approximately 30%.
Cost-effective manufacturing
For a new design solution to be industrialized, it is vital that it can be produced in a rational and cost-effective process, and here too, the collaboration project has delivered. The entire component is manufactured in a single step. C-SMC material is applied onto the aluminum foam-composite material along with special embroidered sensors. To achieve high accuracy during forming, using a servohydraulic press and dedicated tool is recommended. The integrated sensors can measure temperature, humidity, and various other parameters within the battery pack that may affect the capacity and lifespan of the battery cells.
“Our results show how the next generation of optimized battery housings can be designed and manufactured. Now we look forward to bringing our solution to interested OEMs and Tier 1 suppliers,” says Dr. Machhammer.
Who has done what in the project?
· AP&T designed and manufactured the tool, and the demonstrator component was manufactured by RISE using a servohydraulic press produced by AP&T.
· RISE manufactured the demonstrator component at its test facility in Piteå, Sweden.
· Fraunhofer IWU designed and conducted simulations of the component.
· FiberCheck designed and manufactured the sensors, which were integrated in the C-SMC/aluminum foam hybrid structure during the one-shot compression molding conducted at RISE.
· Vinnova, Sweden’s innovation agency, contributed funding.
