Isolating Contiguous Fe Atoms by Forming a Co-Fe Intermetallic Catalyst from Spent Lithium-Ion Batteries to Regulate Activity for Zinc-Air Batteries

The recycling of spent lithium-ion batteries (LIBs) has become a necessity for recovering valuable resources and protecting the environment to support sustainable development. We report the design of a highly efficient CoFe/C catalyst by combining the Co and Fe wastes from spent LIBs with sawdust-derived carbon, which were cathode materials in zinc- air batteries (ZABs). As a result of the electrostatic attraction between the Co3+/Fe3+ cations and the hydroxyl groups in sawdust, CoFe nanoparticles are uniformly dispersed in the CoFe/C catalyst after annealing. The Fe atoms in the CoFe nanoparticles are all isolated into single sites by the Co atoms, which redistribute the electrons in the CoFe/C catalyst. The catalyst produced a Pt-like dissociative mechanism, contribu ting to an excellent oxygen reduction reaction performance. After assembly in ZABs, the CoFe/C catalyst cathode exhibits a long cycling stability of 350 h and an impressive power density of 199.2 mW cm(-2). The CoFe/C catalyst cathode has also been used in flexible ZABs to power LEDs or charge a mobile phone. The work combines spent LIBs with sawdust to fabricate high-performance catalysts, which could reduce environmental pollution and realize high economic value.

Automated summary

In this study, a highly efficient CoFe/C catalyst was designed by combining spent lithium-ion batteries with sawdust. The catalyst exhibited excellent performance in zinc-air batteries, showing high oxygen reduction reaction activity, long cycling stability, and impressive power density. It was also successfully applied in flexible zinc-air batteries to power LEDs or charge a mobile phone.