A selective separation-recovery process based on tuning organic acid was proposed to the resource recycling of spent lithium-ion batteries (LIBs) for the first time. The low-cost preparation of CoFe₂O₄, reuse of waste acid and recovery of Li can be realized in this process, simultaneously. Li and Co in spent LIBs can be leached efficiently using citric acid as a leaching agent, and separated effectively from leaching solution by tuning oxalic acid content. The results from the characterizations of the prepared CoFe₂O₄ (CoFe₂O₄-LIBs) show that it possesses higher ratio of Co(II)/Co(III) and Fe(II)/Fe(III), larger surface specific area and more number of acid sites in comparison with pure CoFe₂O₄. Besides, CoFe₂O₄-LIBs was used to activate peroxymonosulfate (PMS) for the degradation of bisphenol A (BPA). Interestingly, its degradation performance is superior to that of pure CoFe₂O₄ and the related Co-based catalysts. The excellent degradation performance can be maintained in presence of inorganic ions (e.g., $\text{C}{\text{l}}^{-}$, $\text{HC}{\text{O}}_3^{-}$, ${\text{H}}_2\text{P}{\text{O}}_4^{-}$ and $\text{N}{\text{O}}_3^{-}$) with high concentration or humic acid. Moreover, surface-bound $\text{S}{\text{O}}_4^{\text{∙}-}$ is considered as the main reactive species for the degradation of BPA. More importantly, CoFe₂O₄-LIBs can be readily recycled by using an external magnet and own superior ability of regeneration.

首次针对废旧锂离子电池（LIBs）的资源回收提出了一种基于调谐有机酸的选择性分离回收工艺。_{该工艺可同时实现CoFe 2} O ₄的低成本制备、废酸的再利用和Li的回收。使用柠檬酸作为浸出剂可以有效地浸出废锂离子电池中的锂和钴，并通过调节草酸含量从浸出液中有效分离。制备的 CoFe ₂ O ₄ (CoFe ₂ O _{4-LIBs)表明，与纯CoFe 2} O ₄相比，它具有更高的Co(II)/Co(III)和Fe(II)/Fe(III)比、更大的比表面积和更多的酸位点。此外，CoFe ₂ O ₄ -LIBs 用于活化过氧单硫酸盐（PMS）以降解双酚A（BPA）。有趣的是，它的降解性能优于纯CoFe ₂ O ₄和相关的Co基催化剂。在无机离子（如$\text{C}{\text{l}}^{-}$,$\text{HC}{\text{○}}_3^{-}$,${\text{H}}_2\text{磷}{\text{○}}_4^{-}$和$\text{ñ}{\text{○}}_3^{-}$) 与高浓度或腐殖酸。此外，表面结合$\text{小号}{\text{○}}_4^{\text{∙}-}$被认为是降解 BPA 的主要活性物质。更重要的是，CoFe ₂ O ₄ -LIBs可以很容易地通过使用外部磁体进行回收，并且具有优越的再生能力。