(385j) Synthesizing Highly Crystalline Graphite Powder for Lithium-Ion Battery Anodes from Bulk Polyethylene Waste

Upcycling plastic waste into graphite solves an issue controlling supply chain stability and creating a new path for graphite manufacturing. However, synthesizing graphite from plastic waste, particularly polyethylene (PE) plastics, remains a significant challenge because it requires a stabilization process that has not been studied as a pathway for large-scale upcycling of bulk plastic wastes. In this work, we demonstrated a straightforward method of air processing yielding a carbonaceous material (or carbon char) from PE bulk plastic waste using solid additives. The air processing developed in this study overcomes the oxygen diffusion bottlenecks for processing bulk PE waste, therefore achieving char yield over three orders of magnitude with values as high as 20 wt.% from bulk PE plastics, compared to without using solid additives. We also proved that thermally stabilized PE materials can be converted into highly crystalline flake graphite via low-temperature catalytic graphitization. The assembled anode PE-derived graphite showed comparable electrochemical performance, such as reversible rate performance and long-term cyclic stability, to the current-use battery-grade graphite, thus providing a scalable method to upcycle PE plastic waste into high-value carbon materials and is adaptable to practical applications.