Investigating the environmental impacts of different direct material recycling and battery remanufacturing technologies on two types of retired lithium-ion batteries from electric vehicles in China.

• Life cycle assessment of different advanced direct materials recycling routes for two types of batteries is conducted. • The carbon footprint and cumulative energy demand can be significantly reduced by battery remanufacturing with recycled materials. • Eighteen environmental indicators of NCM and LFP batteries are comprehensively investigated. • Environmental assessment can promote the development of direct material recycling technology for batteries. Recycling lithium-ion batteries from electric vehicles is a meaningful way to alleviate the global resource crisis and supply chain risks. However, the environmental impacts caused by different advanced recycling technologies of batteries have not been extensively discussed. This study conducts a process-based life cycle assessment for three typical direct recycling methods and a hydrometallurgical recycling method for the lithium nickel cobalt manganese oxide (NCM) and lithium iron phosphate (LFP) batteries. Then, the potential of reducing the environmental burden through battery remanufacturing with recycled materials is investigated. The results show that the environmental burden of direct material recycling of NCM and LFP batteries is reduced by more than 10% and 30% compared with that of hydrometallurgy. Most environmental indicators of NCM are higher than those of LFP during the recycling process due to the difference auxiliary materials and recycled products. If only cathode materials and foils are recycled, the smallest environmental difference between NCM and LFP is only 1.6%. Compared with batteries manufactured with raw materials, the environmental impacts of NCM and LFP batteries remanufactured with recycled materials can be reduced by more than 20% and 32%. Moreover, the more battery materials obtained by the direct material recycling routes, the greater the environmental benefits through battery remanufacturing. [ABSTRACT FROM AUTHOR]