Regulating and regenerating the valuable metals from the cathode materials in lithium-ion batteries by nickel-cobalt-manganese co-extraction

Effective recycling of valuable metals from the spent lithium-ion batteries (LIBs) is conducive to the rational utilization of resources and environmental protection. To shorten the recovery process and directly obtain the high-pure regenerated products, solvent extraction (co-extraction) method was employed in this work. Here, 3 mol/L (M) hydrochloride (HCl) without reductant was used as leaching agent for the leaching of cathode material, resulting in the leaching efficiency of all metals exceeding 99%. Subsequently, di-(2-ethylhexyl) phosphinic acid (P227) was used to co-extract transition metals directly from the leachate and separate them from lithium (Li). The composition of nickel (Ni), cobalt (Co), and manganese (Mn) extracted into the organic phase can be controlled by changing the extraction conditions, and the type of the cathode material was also regulated simultaneously. Finally, the loaded organic phase with a Ni-Co-Mn ratio of 1:1:1 was completely stripping with 0.4 M HCl, and the LiNi1/3Co1/3Mn1/3O2 was regenerated by oxalic acid co-precipitation the stripping solution and high temperature calcination. The regenerated LiNi1/3Co1/3Mn1/3O2 exhibits excellent electrochemical performance with 150.0 mA h g(-1) discharge capacity at 0.5 C. Therefore, the demonstrated separation and preparation integration process not only realizes the regeneration of the battery but also promotes the co-extraction technique to practical application.

Automated summary

By employing the solvent extraction method, this research successfully recovered valuable metals from spent lithium-ion batteries, achieving high efficiency metal recovery and regenerated product preparation. The control of nickel, cobalt, and manganese extraction ratios by adjusting extraction conditions and cathode material type led to the excellent electrochemical performance of the regenerated LiNi1/3Co1/3Mn1/3O2.