Greater range for electric vehicles
Electric propulsion is an important building block in the development of a climate-friendly transport system. One of the associated challenges is the loss of range in such vehicles during winter.
Fuel-powered vehicles are heated by the waste heat created by the combustion process in the engine. In the case of electric cars, on the other hand, the same battery that drives the car must also provide the power to keep the vehicle at a comfortable temperature. As a result, the battery loses more energy, reducing the car’s range by up to 50 percent on cold days.
The heat storage technology developed by DLR scientists at the Institute of Vehicle Concepts in Stuttgart, in conjunction with the Institute of Materials Physics in Space at the Cologne site and other partners from the felds, of industry and research, can take over the heating function in an electric car and thus substantially increase the range of electric vehicles at low outdoor temperatures.
Using metallic latent heat storage, the researchers were able to develop an energy storage system that can store heat at a very high energy level and thus completely relieve the drive battery of the requirement to heat the interior of the car, too. Metallic latent heat storage materials, such as aluminium-silicon alloys, have a very high specifc energy density, resulting in small, lightweight storage systems.
In a phase-change material, latent heat is absorbed by the material and it changes from one phase to another, for instance from solid to liquid. This heat can be released again by the opposite phase transition. One familiar example of this is pocket warmers, which release energy when the liquid inside them solidifes. With a small volume and tiny mass, they store more energy than other types of thermal storage materials and are therefore well suited for space-saving installation in electric cars.
In addition to increasing range and comfort, heat accumulators should also reduce costs for electric vehicles. By using cost-effcient, readily available storage materials, combined with a simple system design, high-performance thermal storage materials are much less expensive than the traction batteries in electric vehicles, and can thus contribute to sustainable and affordable mobility.
German Aerospace Center (DLR)
Mirko Klein Altstedde · E-Mail: firstname.lastname@example.org · DLR.de/en