Closed-loop recycling of cathode material from spent lithium-ion batteries via collaborative leaching and direct...

The efficient recycling of valuable metals in spent lithium-ion batteries is extremely important to alleviate the imblance between supply and demand of key metals. This article focuses on the direct regeneration mechanism of ternary cathode materials, with the objectives of pretreatment, valuable metal leaching, and in-situ recombination of waste lithium-ion batteries. Results show that the transition metals of cathode materials were reduced to metal oxides including CoO, NiO and MnO after reduction roasting. The leaching efficiency of Ni, Mn, and Co were 91.27 %, 87.45 %, and 88.57 %, respectively at a reaction time of 40 min and a reaction temperature of 80 °C. Subsequently, in-situ regeneration research of motor materials was conducted. The regenerated cathode material presents high sphericity and uniform particle size distribution and a complete layered α-NaFeO₂ crystal structure with a low cation mixing degree and layered structure. Besides, the crystal structure of the material assumes clear lattice fringes and a good crystallization degree. The electrochemical results show that the regenerated materials exhibit excellent reversible discharge capacity and cyclic stability of 143.7 mAh/g first discharge capacity, and the reversible capacity remained at 137.2 mAh/g after 50 cycles, with a retention rate of 94.8 %, which has the application prospect of commercial electrode materials. The proposed recycling process in this paper lays a theoretical foundation for developing a short-range, clean, and green recycling process for spent lithium-ion batteries.