We are going to say this right up front. The following is not another “We made a better battery in the lab and it should be in production in 5 to 10 years” story. German researchers at Fraunhofer Institute for Materials and Beam Technology IWS have created a new way to make lithium-ion batteries using a dry film instead of the semi-liquid paste employed today. The result is a better battery that is cheaper to manufacture and kinder to the environment. And it is already in small scale production! Here are the details.
Believe it or not, there is a connection between lithium-ion batteries and the manufacture of cassettes. Early li-ion battery cells were made using machinery originally designed for making audio tape. While the technology has been updated over the years, the basic process is still the same. Take a substrate like mylar or aluminum, slather it with a coating — iron oxide in the case of cassettes, an electrolyte paste loaded with solvents in the case of battery cells — wind it up on big spools, cut it to size, and voila, you’re done!
It’s that electrolyte paste that is the problem. A, it’s highly toxic, which requires elaborate protection systems for workers. B, it’s flammable. C, it takes a lot of time and energy to dry it during the manufacturing process. The Fraunhofer/Beam system eliminates all three of those issues.
“Our dry transfer coating process aims to noticeably reduce the process costs in electrode coating,” emphasizes IWS project manager Dr. Benjamin Schumm. “Manufacturers can eliminate toxic and expensive solvents and save energy costs during drying. In addition, our technology also facilitates the use of electrode materials that are difficult or even impossible to process wet-chemically.”
That last part is important news. This new technology works with sulfur-ion batteries and solid state batteries as well, opening the door to smaller, less expensive batteries with higher energy densities than are possible with today’s technology. “The technology offers great potential to replace conventional processes for paste-based electrode production in the long run,” Schumn tells Phys.org.
And here’s the best part. Finnish battery manufacturer BroadBit has already set up a small scale production line to explore how to commercialize the new technology. If commercial production proves feasible, the new process could lead to new battery factories to supply the needs of German electric car manufacturers. The lack of such factories is of major concern to the industry.
“European carmakers should be especially happy about the lower battery cost implications of the IWS team’s invention,” says a report by OilPrice.com. “These have poured billions into their EV production plans but are excessively reliant on imported battery cells. A homegrown cheaper battery production process could help them to reduce this dependence at a crucial moment when EVs, helped by government policies, have a chance to really take off.”
Dry film battery cells won’t be the end of battery innovations, but could be an important step forward for the EV revolution.