Ефективна гідрометалургійна переробка літій залізо-фосфатних батарей з використанням розчинів оцтової кислоти

• Date: 2025
• Main Authors: Potapenko , O.V., V’yunov , O.I., Potapenko , H.V., Vavilon , K.I., Vyshnevskyi , O.A., Sirosh , V.А., Oliinyk , V.O.
• Format: Article
• Language: English
• Published: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2025
• Subjects: переробка акумуляторів; літій-залізофосфат; чорна маса; вилуговування оцтовою кислотою; гідрометалургія; екологічність
• Online Access: https://www.cpts.com.ua/index.php/cpts/article/view/820
• Journal Title: Chemistry, Physics and Technology of Surface

The selectivity of metal extraction from multi-element waste using the hydrometallurgical process is an urgent task. To extract lithium selectively from a waste, the leaching reagent should ideally react only with lithium, while FePO4 and graphite should remain in a solid state. The use of H2O2 allows one to control the degree of oxidation of the solution by oxidizing Fe2+ to Fe3+, followed by light precipitation, thus effectively suppressing iron leaching. The paper presents a method for processing the “black mass”, after mechanical separation from the current collector, using a solution of acetic acid with addition of hydrogen peroxide. In contrast to the above studies, where the object of processing was exclusively the cathode mass of a lithium iron-phosphate battery, our team used "black mass" as a raw material, which is an intermediate product in the processing of LIB, and raw materials in the processes of hydrometallurgical leaching of metals. The source of the “black mass” in our research was a lithium iron-phosphate battery HWE200A, LF54174200 3.2 V 200Ah (China). The phase composition, morphology, and particle size of the resulting compounds were analyzed by X-ray diffraction and scanning electron microscopy. Quantitative analysis of the concentration of lithium and iron, aluminum, and copper impurities in solutions was performed by Optical Emission Spectroscopy from inductively coupled plasma (ICP-OES) with an ICP spectrometer iCAP 6500 DUO (Thermo Electron Corp.) Using XRD analysis, the phase composition and crystallographic parameters of the obtained compounds and available impurities were determined. According to the results of research by the proposed method of processing the “black mass” with selective extraction of lithium compounds from spent LFP batteries, the degree of lithium extraction from the “black mass” is achieved by about 98 % with two times treating in the mixture of 0.8 M Hac + 5 wt. % H2O2. The presence of lithium in the form of SEI layer on the surface of the anode material was noted, which accounted for about 14 % of the total amount of lithium in the “black mass”. It is proved that the addition of hydrogen peroxide to a solution of acetic acid promotes the oxidation of Fe2+ to Fe3+in the crystal structure of lithium iron phosphate, which leads to a decrease in the solubility of iron. It was determined that the total amount of impurities (Fe, Al and Cu) in solutions of lithium salts did not exceed 1 %, which was precipitated in the form of corresponding hydroxides. The purity of the obtained Li2CO3, FePO4 compounds and graphite is more than 99.9 wt. %, which meets the battery purity standard and allows them to be used for LiFePO4/C synthesis and reuse in LFP batteries.