Production scraps to raw materials: low-cost method for implementing lithium iron phosphate cathode scraps back to production lines

In recent years, the increased production of lithium-ion batteries (LIBs) has been causing significant amounts of production scraps that require efficient, economical, and environmentally viable recycling methods. This study investigates strategies for integrating low-temperature direct recycling of lithium iron phosphate (LFP) production scraps into battery manufacturing. Scrap LFP cathode active material (CAM) was direct recycled at 200 °C in air and 400 °C in N2. The recycled CAM was blended in different amounts (100, 50, 30%-wt) with commercial CAM. Two slurry compositions were considered based on CAM: polyvinylidene fluoride: carbon black ratios (80:10:10 and 92:5:3), and coin cells were manufactured and tested. Results indicate that recycled CAM can be directly reprocessed in new batteries exhibiting excellent electrochemical performance (154 mAh g−1, equivalent to pristine material) when the slurry included 30%-wt CAM recycled at 200 °C in air and 100%-wt CAM recycled at 400 °C in N2. Compared to virgin slurry material cost (9.06 €/kgslurry) and environmental impact (8.27 kg CO2/kgslurry), incorporating 30%-wt CAM recycled at 200 °C in air reduced costs to 6.59 €/kgSlurry and emissions to 6.21 kgCO2/kgslurry, and 100%-wt CAM recycled at 400 °C in N2 corresponded to 3.77 €/kgSlurry and 2.45 kgCO2/kgslurry. These findings clearly demonstrate that closed-loop integration of low-temperature direct recycling of LFP cathode scraps into cell manufacturing reduces material costs and environmental impact while maintaining high electrochemical performance.