Recycling of spent lithium-ion batteries in view of graphite recovery: A review

Given the exponential increase in the number of lithium-ion batteries (LIBs) used in electric cars and the sizeable quantity of waste produced at the end of their lifespans, efficient recycling of used lithium-ion batteries offers tremendous promise for practical application. While considerable efforts have been devoted to the recycling of cathode materials and other valuable components in spent lithium-ion batteries, sufficient attention has not been directed towards the spent anode graphite. Given the risks associated with limited resource supply and environmental pressure, the regeneration of spent graphite anodes from electric vehicle batteries has become a critical issue. As a preferred option, the direct regeneration strategy has been innovatively proposed to recover targeted graphite materials. To better comprehend this topic, three types of graphite are highlighted and categorized based on the source of the LIBs. Their special features, advantages, and challenges are also summarized and evaluated. More significantly, it is anticipated that the outcomes of this work could emphasize the importance of graphite recycling in the overall recycling of the spent lithium-ion battery industry.