Review on the recycling of anode graphite from waste lithium-ion batteries

In the drive to reduce carbon emissions, the widespread adoption of electric vehicles (EVs) has surged, with Lithium-Ion Batteries (LIBs) emerging as the preferred power source due to their environmental benefits and technical advantages. LIBs contain a significant proportion (12%—20%) of graphite, crucial for their anode's electrode active material, sourced primarily through mining and synthesis. However, concerns arise as a few countries, notably China, Turkey, and Brazil, control over 78% of the world's natural graphite reserves, highlighting potential supply chain risks. In addition to that, synthesizing graphite is expensive, and with the ever-increasing demand for EVs, the prices are expected to increase even further. Recycling graphite from waste LIBs extracted from EVs and electronic devices could potentially be a secondary source of graphite. This recycled graphite source can mitigate supply chain risk, preserve natural resources, lower prices, and decrease environmental pollution. This comprehensive review examines various pretreatment techniques and methodologies for recycling graphite from waste LIBs. It also provides a comparative discussion on the purity and recovery of graphite, its challenges, and prospects in LIB recycling technologies. This review serves as a valuable guide for researchers seeking sustainable practices and recycling methodologies in the EV industry.