Old batteries as raw material: upcycled cells last about twice as long in tests
A team at Worcester Polytechnic Institute builds pouch cells solely from cathode and graphite material recovered from battery waste. They achieved roughly twice the cycle life.
Archive image · Photo: Kenneth C. Zirkel / Wikimedia Commons, CC BY-SA 4.0 (cropped and resized)
Researchers led by Yan Wang at Worcester Polytechnic Institute (WPI) in the US state of Massachusetts have recovered new material for lithium-ion batteries from battery waste – for the cathode as well as the graphite anode. The results were published in the journal Advanced Energy Materials (DOI 10.1002/aenm.71680); WPI presented them on 16 October.
The team converted mixed, low-nickel cathode material into an NMC622 cathode, while recovered graphite was purified and turned into battery-grade anode material. Full pouch cells made only from these materials achieved about twice the cycle life of cells using commercial materials and retained 70 percent of their capacity after 2,590 charge cycles. According to WPI, the cathode transports lithium ions better, and fewer side reactions occurred.
The process also performs well overall, according to the release: more than 95 percent of the waste materials could be used. Compared with a reference recycling route, greenhouse-gas emissions fell by 27 percent and energy consumption by 29.4 percent, while profitability rose by 22.9 percent.