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 Li_xCoO₂ 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, Li_1.05CoO₂ 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.