The two biggest challenges being faced by the composites industry are waste and the cost of production. Solve those two problems and you make composites the default choice for thousands of applications. Both are being addressed through an innovative project in Germany that is taking carbon fiber waste and applying it to making better batteries. It turns out carbon fiber works very well for this application.
Sustainable recycling is something that has eluded composite manufacturers since the inception of the industry. The primary hindrance to recycling is cost. Just as it is very expensive to turn carbon tow into useful carbon fiber sheets and tubes, it’s equally expensive to take carbon fiber waste and turn it into something usable without a significant loss of integrity.
German engineers from the Fraunhofer Institute for Chemical Technology think they’ve found a solution. They have developed a process capable of transforming carbon fiber waste into usable material for manufacturing fuel cells and batteries. As proof of concept, they produced a prototype bipolar plate made partially of waste material.
Replacing Graphite with Waste
The German project has been named Graphit 2.0 due to its link with natural graphite. Graphite is an allotropic form of carbon that naturally occurs in various kinds of rocks. It is often used for making batteries and fuel cells, though it is expensive and hard to get a hold of. The emergence of synthetic graphite has greatly reduced manufacture dependence on the natural form. Enter carbon fiber waste.
Through a combined thermal and mechanical recycling process, German engineers were able to harvest a secondary material – a synthetic graphite – from processed carbon fibers. It can theoretically be used in just about any application suitable to other synthetic graphite products. In the case of the German project though, batteries and fuel cells are the main target.
Carbon fiber waste is an ideal material for the project because of the electrically conductive properties of carbon. The success of the German project suggests that manufacturers could utilize their own waste and convert it to synthetic graphite that could then be sold a lot cheaper than natural graphite imported from overseas producers, like China.
Recycling Reduces Production Costs
To understand the magnitude of what the German researchers are working on, consider this amazing statistic: the average wide-body aircraft now taking to the skies is made up of more than 50% carbon fiber reinforced plastics, according to Assembly magazine. The amount of waste produced while fabricating the parts for just one Airbus 350 adds up to more than 65 tons.
Imagine if Airbus could apply the German recycling process to that waste, then turn around and sell the resulting synthetic graphite to battery and fuel cell manufacturers. They would not only cut their own production costs by offsetting them through graphite sales, but the companies that purchase the synthetic graphite would also be lowering their costs of production as well. Cheaper synthetic graphite means cheaper batteries.
Driving the German project is the reality that EU regulations are forcing manufacturers to recycle up to 85% of the total weight of a given vehicle’s waste material. So for every 100 pounds of airplane produced, Airbus is looking to recycle 85 pounds of waste. That is a lot of recycling.
Finding a viable means of recycling carbon fiber without breaking the bank would be a big deal. German researchers are well on their way to figuring out how to combine recycling with innovative new battery and fuel cell technologies. In doing so, they are paving the way for others to come up with additional ways to recycle carbon fiber waste.