Metal conductors fabricated through innovative polymer process by Fraunhofer Institute
The Fraunhofer Institute for Electron Beam and Plasma Technology (FEP) in Dresden, Germany, has developed a groundbreaking roll-to-roll process for producing metal-on-polymer current collectors for lithium-ion batteries. This innovation could revolutionise the battery industry, offering lighter, safer, and more energy-dense batteries that could significantly impact electric vehicles, portable electronics, and energy storage systems.
The process involves precisely applying copper and aluminum layers onto polymer films, replacing conventional metal foils (aluminium for cathodes, copper for anodes) with much lighter polymer substrates coated with metal layers that offer comparable electrical conductivity and thickness. This substitution could potentially lead to a decrease in battery weight, allowing for higher energy densities.
Beyond weight reduction, these polymer-based current collectors also introduce enhanced safety features. In the event of a short circuit, the polymer substrate melts and interrupts the current flow, significantly mitigating the risk of thermal runaway and improving battery safety. The process has been successfully demonstrated in the PolySafe project, where pouch cells made with these metal-polymer collectors showed similar electrochemical performance to conventional cells under various charging and discharging rates.
Key impacts on the future of lithium-ion battery technology include:
- **Weight Reduction:** Substituting conventional metal foils with polymer films coated with metal decreases battery weight, allowing for potentially higher energy densities. - **Enhanced Safety:** Polymer substrates provide a thermal shutdown function by melting upon overheating, reducing fire risks in batteries. - **Scalability:** The roll-to-roll manufacturing technique is adaptable to semi-industrial scale, offering manufacturers a pathway to integrate this technology into mass production. - **Maintained Performance:** Electrochemical tests confirm the new current collectors perform comparably to traditional foils, maintaining cycle stability and charge/discharge behavior.
The Technical University of Braunschweig processed the finished metal-polymer films into pouch cells and tested them for charging and discharging behavior. In these tests, the new current collectors demonstrated comparable performance and cycle stability to conventional reference cells.
This process is intended to replace metal foils as current conductors in lithium-ion batteries, and the development of these metal-polymer current collectors could lay the groundwork for lighter and safer battery cells in the future. The PolySafe project, funded by the German Federal Ministry of Research, Technology and Space, is paving the way for the implementation of this innovative technology.
Science and technology have come together in the development of metal-on-polymer current collectors at the Fraunhofer Institute for Electron Beam and Plasma Technology. This innovation could revolutionize the battery industry by offering not only lighter, safer, and more energy-dense batteries, but also enhanced safety features through the use of polymer substrates that act as a thermal shutdown mechanism in case of short circuits. This advancement, a result of the blending of materials science and manufacturing technology, has the potential to significantly impact electric vehicles, portable electronics, and energy storage systems.
