Bipolar batteries are lithium-ion batteries which, like fuel cells, consist of stacked electrodes connected in series. In contrast to conventional lithium-ion batteries, these electrodes have a "bipolar" structure. This means that the active materials for the cathode of the battery and the active materials for the anode are applied to a common electrode carrier. The individual lithium-ion cells are then no longer packed separately in aluminum housings, but only the finished electrode stack is given a fixed housing. This eliminates the need for housing components and connecting elements, which saves costs and space in the vehicle. Instead, the space freed up can be filled with more active material. This allows the battery to store more energy and increases the vehicle's range. This is the charm of lithium-ion bipolar batteries, which have so far only been manufactured and tested on a laboratory scale.
In order to master the challenges, not only must the framework conditions be right, it also requires close integration of the partners gathered in the project. These range from the manufacture of improved bipolar electrodes based on lithium nickel manganese cobalt oxides and graphite as storage materials (Fraunhofer IKTS), to scaling assembly technology up to 100 x 30 cm² (Thyssenkrupp System Engineering), connecting an electrical battery monitoring system (IAV) and safety simulation to address specific vehicle requirements (Daimler).