Eddy current separation for recovering aluminium and lithium-iron phosphate components of spent lithium-iron phosphate batteries

Abstract

With the rapid development of the electric vehicle market since 2012, lithium-iron phosphate (LFP) batteries face retirement intensively. Numerous LFP batteries have been generated given their short service life. Thus, recycling spent LFP batteries is crucial. However, published information on the recovery technology of spent LFP batteries is minimal. Traditional separators and separation theories of recovering technologies were unsuitable for guiding the separation process of recovering metals from spent LFP batteries. The separation rate of the current method for recovering spent LFP batteries was rather low. Furthermore, some wastewater was produced. In this study, spent LFP batteries were dismantled into individual parts of aluminium shells, cathode slices, polymer diaphragms and anode slices. The anode pieces were scraped to separate copper foil and anode powder. The cathode pieces were thermally treated to reduce adhesion between the cathode powder and the aluminium foil. The dissociation rate of the cathode slices reached 100% after crushing when the temperature and time reached 300℃ and 120 min, respectively. Eddy current separation was performed to separate nonferrous metals (aluminium) from aluminium and LFP mixture. The optimized operation parameters for the eddy current separation were feeding speed of 1 m/s and magnetic field rotation speed of 4 m/s. The separation rate of the eddy current separation reached 100%. Mass balance of the recovered materials was conducted. Results showed that the recovery rate of spent LFP can reach 92.52%. This study established a green and full material recovery process for spent LFP batteries.

A review of physical processes used in the safe recycling of lithium ion batteries

“…[103] applied electrostatic separation on three battery samples, and was able to separate a conductive (Electrode and coating) fraction with a 98.98 % grade, and a nonconductive (polymer) fraction with a 99.6 % grade. Eddy current separators can be utilised to separate ferrous metals, non-ferrous metals, and non-metals [61,104], and also aluminium from copper foils [105]. However to date there is nothing to indicate that these processes are utilised at scale for separation of lithium ion battery components.…”

To shred or not to shred: A comparative techno-economic assessment of lithium ion battery hydrometallurgical recycling retaining value and improving circularity in LIB supply chains

“…Several direct and indirect methods exist and many municipal waste processing sites integrate a variety of these techniques to produce bins of segregated waste with varying values depending on the purity of feedstock and efficiency of the segregation steps. The main sorting methods and the properties on which their separation is based are listed in Table 1 (Gundupalli et al, 2017;Sommerville et al, 2020;Bi et al, 2020;Bi et al, 2019;Al-Thyabat et al, 2013).…”

Exfoliation of Active Materials Synchronized with Electrolyte Extraction from Spent Lithium‐Ion Batteries by Supercritical CO2

“…However, the pyrolytic gas and tar mainly composed of light alkenes, aromatic long chain alkenes and light alcohols will inevitably bring the cost and burden of secondary pollutant treatment. [14] In addition, some innovative experiments were performed by different research groups, involving low-temperature molten salt technology, [15] cryogenic grinding, [16] eddy current separation, [17] ultrasonic-assisted acid scrubbing, [18] aqueous exfoliating and extracting solution (AEES) [19] and waste oilbased methyl ester solvent. [20] Figure 1 shows these innovative explorations in latest years.…”