Cost-effective recycling of spent LiMn2O4 cathode via a chemical lithiation strategy

Abstract

The global lithium-ion battery recycling market is witnessing rapid growth considering the limited mineral resources and environmental sustainability. However, the conventional destructive recycling technology, mainly referred as pyrometallurgy and hydrometallurgy, cannot show obvious advantages in the recovering of low-value cathode (i.e. LiMn2O4, abbreviated as LMO), either judged from the perspective of environment or economy. Herein, we develop a facile and cost-effective chemical lithiation strategy to direct regenerate spent LMO cathode, and further investigate the efficacy of our technology for industrial-scale applications. Pyrene-Li compound, a highly reductive reagent capable of donating both e− and Li+, is adopted as the chemical lithiation agent to heal the Li deficiency in the degraded LMO cathode. Both the Li-deficient LMO model compounds prepared from acid delithiation method and the real degraded LMO harvested from commercial cells can be restored as original with comparable long-term stability as the pristine LMO cathode and even superior rate capability. Life-cycle analysis demonstrates that our approach is superior to conventional metallurgies because of its high economic profitability (2.78 $/kg cell) and minimal environmental impact (527 g GHG /kg cell), thus providing a brand new perspective for the recycling of low-value cathodes.