Scientists at Worcester Polytechnic Institute (WPI) have proposed an approach that could turn mixed lithium-ion battery waste into valuable materials. The study was published in the journal Advanced Energy Materials. The work was led by Professor Yan Wang.
Battery recycling today often focuses on recovering cathode materials - the positive electrode. Mixed waste is difficult to process into high-value products. Wang's team set out to improve two components at once: the cathode material and graphite.
From mixed cathode materials with low nickel content, the researchers produced a high-performance NMC622 cathode. In addition, they purified and modified the recovered graphite to obtain battery-grade anode material (the anode is the negative electrode).
Laboratory tests showed improved lithium-ion transport and cycling stability in the cathode, as well as better interfacial kinetics and durability in the graphite anode. The materials were then used to assemble full pouch cells - soft battery cells in a film casing. These had fewer side reactions, and their service life was roughly twice that of cells with commercial materials: after 2,590 cycles, 70% of capacity remained.
The authors also assessed possible economic and environmental effects. By their calculations, the process makes it possible to use more than 95% of the waste, raise profitability by 22.9%, and cut greenhouse gas emissions by 27% and energy consumption by 29.4% compared with a reference recycling route.
The results point to a path beyond simply extracting raw materials from old batteries: complex waste is turned into components for high-performance batteries. This could support more closed-loop battery production and reduce the resources and energy needed to create new materials. However, these are still laboratory results, not a ready industrial product.