Review on full-component green recycling of spent lithium iron phosphate cathode materials: From the perspective of economy and efficiency

As the core component of electric vehicles, the usage of lithium iron phosphate batteries (LFP) has increased drastically, which led to the increase of the potential environmental threats and waste of resources caused by spent LFP (SLFP). The present paper reviewed the recent recovery technology of SLFP from three main perspectives: efficient pyrometallurgy, comprehensive hydrometallurgy and simple direct regeneration. The effects of different recycling technologies on the recovery of various components in SLFP were systematically expounded and evaluated. Further, recovery cost and treatment efficiency were compared systematically to evaluate the economy and practicability of the recovery technology. In addition, a green, low-cost, effective recovery process was proposed for the recovery of all components in the SLFP combining various existing recovery technologies. The recovery process was divided into four stages: low-cost pretreatment for electrode material dissociation and chemical activity enhancement, green cycle leaching for recovering Li, efficient removal of the impurities in the product after Li extraction to produce pure FePO4, and the direct regeneration. The process achieved the recovery of all components in SLFP and ensured the economy and green of the recycling by combine various technologies. Meanwhile, the value of the recycling was maximized by diversifying product categories.