Supporting Critical Raw Material Circularity – Graphite from Waste LIBS to Zn-Air Batteries

Abstract

The use of Li-ion batteries (LIBs) in electrical vehicles and consumer electronics is continuously on the rise which means that the amount of spent LIB (SLIB) is on the rise as well. The sustainable recycling of SLIB for production of secondary resources will prevent the loss of valuable materials and ensures safe and economical management of used batteries. During industrial black mass recycling process only Co and Ni from SLIBs is currently recycled, though LIBs contain many other valuable materials too. Graphite, which is used as an anode active material in LIBs, is discarded as a waste during industrial recycling process. Repurposing inexpensive waste graphite has a huge potential to be alternative for pristine graphite.In this research a novel way to prepare bifunctional oxygen electrocatalyst from industrially produced and hydrometallurgically leached black mass leach residue is shown. The recycling leach residue is utilized as a valuable raw material, graphite and transition metal (Co, Mn, Ni) source, with N-precursor for the synthesis of N-Me-C graphite-based electrocatalyst. For the first time the battery metal residues, left into SLIBs recycling waste, are strategically exploited to achieve metal co-doping of graphite-based material. Battery derived electrocatalysts demonstrated promising electrocatalytic activity towards ORR and OER in alkaline media. Moreover, the novel bifunctional oxygen electrocatalysts were used in a rechargeable Zn-air battery as an air cathode catalyst and achieved a high-power density of 104 mW·cm-2 (Figure 1). The advantageous electrochemical activity of the catalyst materials was linked with its surface morphology, structure, porosity, and elemental composition.This research shows the great potential of SLIBs black mass leach residue as a resource for the more sustainable production of high performance and low-cost bifunctional oxygen electrocatalyst appliable in Zn-air battery. Figure 1