Toward Joule heating recycling of spent lithium-ion batteries: A rising direct regeneration method

Lithium-ion batteries (LIBs) are critical for the rapid growth of electric vehicles (EVs), but their inherent lifespan leads to numerous retirements and resource challenges. The efficacy of conventional recycling techniques is increasingly compromised by their high energy consumption and secondary pollution, rendering them less responsive to greener and more sustainable requirement of rapid development. Thus, the direct recycling process emerged and was considered as a more expedient and convenient method of recycling compared to the conventional recycling modes that are currently in study. However, due to the reliance on the indispensable sintering process, direct recycling still faces considerable challenges, motivating researchers to explore faster, greener, and more cost-effective strategies for LIBs recycling. Inspiringly, Joule heating recycling (JHR), an emerging technique, offers rapid, efficient impurity removal and material regeneration with minimal environmental impact, addressing limitations of existing methods. This method reduces the time for direct recycling of spent LIBs by a factor of at least three orders of magnitude and exhibits significant potential for future industrial production. Unfortunately, due to the lack of systematic organization and reporting, this next generation approach to direct recycling of spent LIBs has not yet gained much interest. To facilitate a more profound comprehension of rising flash recycling strategy, in this study, JHR is distinguished into two distinctive implementation pathways (including flash Joule heating and carbon thermal shock), designed to accommodate varying pretreatment stages and diverse spent LIBs materials. Subsequently, the advantages of the recently developed JHR of spent LIBs in terms of material performance, environmental friendliness, and economic viability are discussed in detail. Ultimately, with the goal of achieving more attractive society effects, the future direction of JHR of spent LIBs and its potential for practical application are proposed and envisaged.