Fraunhofer Institute for Ceramic Technologies and Systems in Dresden, Germany, says it has developed new technology in the lab that could increase electric car range to 1,000 kilometers or more. The secret? More batteries in the same space. Ceramics play a large part in the process. In a conventional battery pack, the individual battery cells are surrounded by a separate outer casing. All those casings take up half of the space inside each battery pack. The connections to each cell are points where electrical resistance is high, reducing available power.
The EMBATT from Fraunhofer does things differently. Individual battery cells are not strung together separately side by side in small sections. Instead, they are stacked directly one above the other across a large area. The entire structure for the housing and the contacting is therefore eliminated, which allows more batteries to fit into every car. Conversely, a car could use a smaller, less expensive battery to keep retail prices down.
Fraunhofer has developed a bipolar electrode, an idea borrowed from fuel cell technology. A metallic tape is coated on both sides with ceramic storage materials. That makes one side the anode and the other side the cathode. “We use our expertise in ceramic technologies to design the electrodes in such a way that they need as little space as possible, save a lot of energy, are easy to manufacture, and have a long life,” says Dr. Mareike Wolter, project manager at Fraunhofer.
Because of the direct connection of the cells in the battery pack, the current flows over the entire surface of the battery, dramatically reducing internal electrical resistance. In addition, the electrodes of the batteries are designed to release and absorb energy very quickly. “With our new packaging concept, we hope to increase the range of electric cars in the medium term up to 1000 kilometers,” says Wolter.
The scientists at Fraunhofer mix ceramic powders with polymers and electrically conductive materials to form a suspension. “This formulation has to be specially adapted for the front and back of the tape,” Wolter explains. It is applied to the tape in a roll-to-roll process. “One of the core competencies of our institute is to adapt ceramic materials from the laboratory to a pilot scale and to reproduce them reliably,” Wolter says.
Like all laboratory advances, commercial applications may be many years away. Fraunhofer is working with partners ThyssenKrupp System Engineering and IAV Automotive Engineering to refine the process. It expects to have prototypes of its new batteries installed in electric cars for testing purposes by 2020.
Source: Electric Cars Report