Search

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., C l − , HC O 3 − , H 2 P O 4 − and N O 3 − ) with high concentration or humic acid. Moreover, surface-bound S O 4 ∙ − 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.

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO2 and β-MnO2 are one-step prepared for catalytic oxidation of VOCs. The recovery rate of manganese can be approximately 100% while the recovery efficiency of cobalt, nickel, and lithium is less than 15%, 2%, and 1%, respectively. Compared with pure α-MnO2 and β-MnO2, transition metal-doped α-MnO2 and β-MnO2 exhibit better catalytic performance in toluene and formaldehyde removal attributed to their lower crystallinity, more defects, larger specific surface area, more oxygen vacancies, and better low-temperature redox ability. Besides, the introduction of the appropriate proportion of cobalt or nickel into MnO2 can significantly improve its catalytic activity. Furthermore, the TD/GC-MS result indicates that toluene may be oxidized in the sequence of toluene - benzyl alcohol - benzaldehyde-benzoic acid - acetic acid, 2-cyclohexen-1-one, 4-hydroxy-, cyclopent-4-ene-1,3-dione - carbon dioxide. This method provides a route for the resource utilization of spent LIBs and the synthesis of MnO2.