The German company Duesenfeld discharged the battery completely and filled it with nitrogen in a closed grinder. The flammable electrolyte liquid is evaporated and pumped out, followed by the precipitation of powder. In this way, 96% of the materials in the battery can be recycled.
With the increasing trend of electric mobility, a series of high-performance electric vehicles have been put on the market. Now, it's time to think about what to do with the batteries when these cars are involved in accidents or scrap. Since March 2019, researcher Rolf Widmer and colleagues at the Swiss National Federal Laboratory Empa have been working with the Car Recycling Foundation on related projects. They analyze car recycling systems, study costs and ecological footprints, and perform model calculations to estimate the number of used batteries in the future. Finally, they propose appropriate strategies.
Cold or hot cycle?
Most lithium-ion batteries do not use the cold crushing method like Duesenfeld, but instead heat them in the oven before grinding. The market leader in this regard is Umicore of Belgium. During thermal cycling, the battery's thin copper foil melts, along with cobalt and nickel, forming a recyclable alloy. However, lithium, graphite, liquid electrolytes, and aluminum in the battery burn into slag.
In addition to heat recovery and cold crushing with inert gas, there are other automatic decomposition methods. In order to prevent the fire, Swiss professional battery recycling company Batrec Industrie AG shattered some batteries in a humid environment. Empa experts will compare all methods.
Transportation problem
Finding the best recycling system must not only consider crushing, but also establish a supply chain. Daniel Christen, managing director of the Swiss Automobile Recycling Foundation, said: "Car batteries damaged during an accident may suddenly burn. These batteries have so far only been transported in special containers as dangerous goods." This is expensive and time-consuming. . Christen is looking for a cheaper solution to "disarm" the battery and deliver it to the processing company. Some methods are available: For example, the Swiss Blubox company uses a "Firebox" made by a Dutch manufacturer. This is a freight container with a built-in fire extinguishing system that can hold a whole vehicle or a larger capacity "disassembled" battery.
Finally, freight forwarders and car recyclers must be trained to avoid injuries when recycling end-of-life electric vehicles. There is now a related database that provides information to rescuers. Firefighters can enter the license plate number on the computer to identify electric vehicles on the spot. The tablet will show how to disconnect the battery. With the same information, electric vehicles can also be disassembled safely.
Many issues need to be resolved
Many issues remain to be resolved before a recycling system is established. How will the used battery market develop? In the future, it is worthwhile to repair used batteries with new battery components and put them back on the market, just like refurbishing an engine or transmission. In "Second Life", will old car batteries become fixed solar storage units? How long does it take for a decommissioned battery to enter a recycling company? Do we need to increase our recycling capacity, or do automakers collect and recycle most of the batteries themselves?
This will largely depend on the market prices of raw materials, such as the value of lithium, cobalt, nickel and graphite. At the same time, depending on the price and performance of the new battery, and affected by the political environment, the latter can set the framework conditions and issue regulations.