The performance data of the lightweight electrical sports car "Elise-E" that Evonik Industries presents are impressive: The vehicle weighs 950 kg, has a power of 150 kW, accelerates from 0 to 100 km/h in 4.4 seconds. The top speed is limited to 200 km/h. "The purpose of exhibiting the vehicle is to show the automotive industry what can be achieved with our expertise in chemicals," says Klaus Hedrich, Head of the Evonik Automotive Industry Team. Thanks to the combined use of innovative storage technology, lightweight components, and tires with reduced rolling resistance, the sports car is the first-ever model to weigh less than 1,000 kilograms. With the exhibit, Evonik is demonstrating that electrical cars, which are currently used primarily as city vehicles, can also be part of the sports car segment.
The vehicle is a combination of automotive components made with the specialty chemical components of the Essen-based Group and the sophisticated automotive technology of the British sports car manufacturer Lotus. The necessary power comes from a lithium ion battery with the globally unique Cerio storage technology. At the core of this battery is the ceramic high-performance separator Separion, which is extremely thin and highly heat-resistant. It separates the anode reliably from the cathode and sets new standards for lithium ion cells in terms of cycle stability, performance output and safety by using additional components. In addition, the separator allows for the highly compact design of the battery cells, which results in high energy density at a low weight.
The weight of the electrical sports car’s body has also been reduced with Evonik technologies. The sandwich structure with the structural foam Rohacell and carbon fibers makes the body 60-70 percent lighter than a comparable steel structure. Evonik applied a new resin infusion process with an innovative epoxy resin formula based on the Vestamin hardener technology to manufacture it. This process allows for class-A surfaces and reliable quality in the serial manufacture of composite automotive body parts. Side windows made of Plexiglas also contributed to the weight reduction, as they have a weight-saving potential of 40-50 percent compared to conventional mineral glass. In addition to reduced weight, further advantages of the glazing consist of excellent transparency, high resistance to weather, pleasant acoustics and excellent shaping properties.
Vehicles with less weight and high power have to be safe and sustainable on the road. In this fast-running electrical vehicle, this is ensured by special lightweight tires, which were developed with high-performance Silica Ultrasil and the silane Si 363 manufactured by Evonik. They reduce the rolling resistance of the tires by approx. 20 percent, leading to energy savings of about five percent. A look at the scale provides evidence that the effort has paid off handsomely: This is the first time for such a sports car to weigh less than 1,000 kg.
