Environmental and economic assessment of structural repair technologies for spent lithium-ion battery cathode materials

The existing recycling and regeneration technologies have problems, such as poor regeneration effect and low added value of products for lithium (Li)-ion battery cathode materials with a low state of health. In this work, a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO2 cathode materials. Compared with the spent cathode material with >50% Li deficiency, the Li/Co molar ratio of the regenerated LiCoO2 cathode is >0.9, which completely removes the Co3O4 impurity phase formed by the decomposition of LixCoO2 in the failed cathode material after repair. The repaired LiCoO2 cathode materials exhibit better cycling stability, lower electrochemical impedance, and faster Li+ diffusion than the commercial materials at both 1 and 10 C. Meanwhile, Li1.05CoO2 cathodes have higher Li replenishment efficiency and cycling stability. The energy consumption and greenhouse gas emissions of LiCoO2 cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydrometallurgical recycling processes.