GOTHENBURG, Sweden—Engineers at the Chalmers University of Technology here have developed a massless energy storage device that functions as both a battery and a load-bearing structure. The structural battery could increase the driving range of electric cars and enable lightweight airplanes, ships and trucks, in addition to a variety consumer electronic devices.

Structural batteries are materials that, in addition to storing energy, can carry loads. In this way, the battery material can become part of the actual construction material of a product, which means that much lower weight can be achieved.

The Chalmers battery is made out of carbon-fiber composite that is as stiff as aluminum and energy-dense enough to be used commercially. It has an energy density of 30 watt-hours per kilogram.

"Investing in light and energy-efficient vehicles is a matter of course if we are to economize on energy and think about future generations,” explains Leif Asp, Ph.D., a materials science professor who is leading the R&D project. “We have made calculations on electric cars that show that they could drive for up to 70 percent longer than today if they had competitive structural batteries.”

Asp says there is still a lot of engineering work to be done before the batteries can be mass produced. However, a Swedish start-up company called Sinonus AB is in the process of developing the technology.