Metal conductors are being developed through innovative techniques by researchers at Fraunhofer.
A groundbreaking development in the field of lithium-ion battery technology is taking shape, thanks to a new approach to current collectors developed within the "PolySafe" project. Funded by the Federal Ministry of Research, Technology, and Space, this project aims to replace traditional metal foils as current collectors with lighter and safer alternatives.
The Fraunhofer Institute for Electron Beam and Plasma Technology FEP in Dresden has developed a roll-to-roll process for coating polymer films with copper or aluminum on both sides. This process produces metal-on-polymer current collectors that are lighter than conventional metal foils, potentially increasing the energy density of lithium-ion battery cells.
The coating process applies copper and aluminum layers up to one micrometer thick per side on 12-micrometer thick PET films. Remarkably, the coating is applied to both sides of the PET films and without significant wrinkling on rolls up to 60 centimeters wide.
The resulting metal-polymer current collectors can achieve electrical conductivity and layer thickness comparable to conventional metal foils. In testing, these new current collectors showed similar power and cycle stability to conventional reference cells, confirming that the new technology can maintain battery performance while offering benefits in weight reduction and safety.
The polymer carrier in the new current collectors is designed to melt in the event of a short circuit, interrupting the current flow and preventing thermal runaway. This feature enhances battery safety by preventing dangerous overheating.
Pouch cells made with these metal-on-polymer collectors were tested for their charging and discharging behavior. Practical tests found comparable electrochemical performance and cycle stability as those made with conventional metal foils, confirming that the new technology can maintain battery performance while offering benefits in weight reduction and safety.
The roll-to-roll process efficiently deposits copper or aluminum layers up to about 1 µm thick on both sides of PET films, making it suitable for semi-industrial manufacturing and integration into electrodes. This approach thus provides a promising way to produce lithium-ion batteries that are both safer and have higher energy density through advanced current collector design and materials engineering.
In summary, the innovative metal-polymer current collectors developed within the "PolySafe" project offer several potential benefits:
- Increased energy density: The lighter metal-on-polymer collectors reduce battery weight, allowing more active material per cell volume or weight. - Improved safety: The polymer substrate melts under excessive heat conditions (e.g., short circuit), acting as a thermal fuse that interrupts current and prevents thermal runaway. - Maintained performance: Electrochemical tests found comparable charge/discharge behavior and cycle stability to conventional foil cells. - Manufacturing feasibility: The roll-to-roll coating process is scalable and produces high-quality, wrinkle-free films suitable for battery production.
This promising development could pave the way for safer, higher-energy lithium-ion batteries, with potential applications in a wide range of industries.
- The advancements in lithium-ion battery technology, achieved through the PolySafe project, have significant implications for the field of science, as the project aims to improve battery safety and increase energy density by employing lighter metal-on-polymer current collectors.
- In the realm of health-and-wellness and fitness-and-exercise, this development could lead to the creation of wearable devices with longer battery life, thanks to the increased energy density offered by the new metal-polymer current collectors.
- This breakthrough in lithium-ion battery technology, with its emphasis on safety and energy efficiency, is a notable contribution to general-news and technology domains, potentially revolutionizing various industries that rely on lithium-ion batteries, from electronic devices to electric vehicles.
