Direct recycling of spent cathode material at ambient conditions via spontaneous lithiation
摘要
Direct recycling is a promising route for the sustainable management of end-of-life spent cathodes. However, its practical implementation is greatly restricted as most existing methods require heating or high-pressure conditions during the lithiation step to overcome the thermodynamic obstacles and realize lithium replenishment. In this study, we explored a strategy to realize spontaneous lithiation via simple solid–liquid mixing at ambient conditions. The thermodynamic barrier of the lithiation reaction was reduced by self-adsorbed amyloxylithium, which can spontaneously adsorb on the surface of degraded cathode particles without an external driving force. This strategy can regenerate both laboratory-dismantled LiNi0.6Co0.2Mn0.2O2 from 10 Ah pouch cells and industrial-dismantled LiNi0.5Co0.2Mn0.3O2 black mass. The capacity retention rate of a 1 Ah pouch cell assembled using regenerated LiNi0.5Co0.2Mn0.3O2 as cathode material was 80.5% after 500 cycles. The proposed strategy has big economic advantages over conventional pyro- and hydrometallurgical methods, as evidenced by the techno-economic analysis, accompanied by obvious environmental benefits, as evidenced by reduced CO2 emissions. This work provides a viable approach for the direct recycling of spent cathode material, improving the circularity of the battery industry.