EMBATT bipolar battery


Bipolar cell concept for Li-ion batteries.
FESEM image of a bipolar LFP/LTO electrode.

The EMBATT technology is a bipolar battery concept developed by Fraunhofer IKTS and partners from the industry with the aim of achieving energy densities of more than 450 Wh/l on the system level based on conventional Li-ion active materials, thus increasing the reach of electric vehicles The standout feature of the bipolar structure is that both electrodes are applied onto the same distributor foil, which means they can be stacked directly onto one another and electrically wired in series. Compared with a monopolar structure, a large part of the packaging and connecting materials can be done away with, and the battery can reach higher system voltages.

Bipolar electrode foils differ from conventional electrodes in the materials used and in that they require special, highly accurate processing. Because of the stacked structure and the wiring in series, the concepts poses high quality requirements to the coating technology; accurate balancing becomes paramount. The working group manufactures electrodes coated on both sides with the LFP/LTO material system up to 300 mm coating width in a roll-to-roll process; then the electrodes are used in bipolar lab test cells by the "Cell Design and Testing" working group. In order to increase the energy density of the EMBATT battery still further, the working group currently strives to introduce new electrolyte materials with higher capacity