Electrodes for electric energy storage

Schematic design of a double layer capacitor
© Fraunhofer IWS Dresden
Schematic design of a double layer capacitor

Roll-to-roll and aqueous solution based processes were developed to deposit anode and cathode coatings for lithium ion cells. This effort is part of a larger project DeLIZ, which involves a production technology demonstration center for lithium ion cells. Using water as a solvent is a safer and less costly alternative to the widely used but flammable NMP. The main components for the deposition at the anode side are graphite powder (MCMB) , a polymeric binder and water. The cathode is made from a LiFePO4 powder suspension, binder and water as well. The coated and calendered electrode foils can be cut using an IWS-developed industrial remote laser cutting process.

Related IWS projects address the development of materials and electrode for double layer capacitors (supercaps). The development and testing efforts focus on highly porous carbon materials. A special pore design shows a significant increase in energy and power densities. Roll-to-roll processes are used as well to efficiently produce supercap electrodes.