Laser-based drying of battery electrode layers

In order to introduce competitive mass market solutions for the production in electro mobility, costs for battery cell manufacturing have to be significantly reduced. The substitution of conventional furnace processes through innovative laser processes presents a significant energy saving potential as well as a considerable reduction of the installation space for the corresponding roll-to-roll system. A laser-based drying process of water-based battery electrode films (anodes as well as cathodes) is developed which needs to fulfill the requirement of not exceeding temperatures of 240°C in the temperature-sensitive, 50-100µm thick films. By laser-drying of battery electrodes, coin cell capacities of about 355 mAh/g (equal to those of conventionally produced cells) can be achieved. By implementing a technology demonstrator in the form of a laser drying module, the scalability of the process can be shown in an in-line coating demonstrator. Using 450 W of laser power, area rates of about 50 cm²/s can be achieved while reducing the energy consumption by about 50% in comparison to conventional oven processes. Among the application fields are laser-based drying of conventional battery electrodes in mobile devices as well as solid state electrodes in thin film batteries for small and mobile applications such as smart patches, lighted labelling etc.