Oxygen-driven selective lithium recovery from spent LiFePO4 batteries using malic acid

Solar-assisted lithium metal recovery from spent lithium iron phosphate batteries

Lithium recovery from spent LiFePO4 batteries is significant to prevent resource depletion and environmental pollution. In this study, the employment of "water in salt" electrolyte in LiFePO4 battery enlightened us to develop a novel method for the selective recovery of lithium from spent LiFePO4 batteries through oxidizing LiFePO4 to FePO4 with sodium persulfate (Na2S2O8). Effect of several variables on the Li leaching efficiency was investigated. Additionally, combined thermodynamic analysis and characterization of XRD, XPS were employed to investigate the leaching mechanism. More than 99% of Li can be selectively leached in 20 min at ambient temperature with only 0.05 times excess of Na2S2O8. The high leaching efficiency can be ascribed to the stability and without destruction for the solid structure during the oxidation leaching. A closed-loop process was then proposed for recycling entire spent LiFePO4 batteries, and finally high purity Li2CO3 (99 wt %) was successfully prepared. The process is economically feasible and environmentally friendly and has great potential for the industrial-scale recycling of spent LiFePO4 batteries.

Selective recovery of lithium from spent lithium iron phosphate batteries.

Simultaneous cathode liberation and selective lithium recovery from spent LiFePO4 batteries via sodium persulfate–assisted roasting

One of the most significant challenges for resource conservation and sustainable energy development is the separation of lithium from spent lithium-ion batteries. In this study, a simple and cost-effective direct electrochemical approach was employed for recovering lithium from spent LiFePO4 batteries using a chemometric approach. A two-step process was applied to recover Li from the spent LiFePO4 batteries. The process begins with the leaching of lithium into the Na2SO4 electrolyte solution, followed by the precipitation of lithium as Li3PO4 in a subsequent step. The electrochemical leaching conditions for lithium were investigated through a face-centered central composite experimental design. The leaching efficiency and selectivity of lithium were achieved at about 92 and 96%, respectively. The selectivity of the process was confirmed by scanning electron microscopy with energy dispersive X-ray spectroscopy and inductively coupled plasma optical emission spectroscopy analysis, which clearly showed that the other metals remained nearly constant prior to as well as following the leaching process. Furthermore, the X-ray diffraction and inductively coupled plasma optical emission spectroscopy analysis verified the precipitation and purity efficacy of recovered Li3PO4, which were 89 and 99%, respectively. The direct electrochemical lithium recovery from lithium-ion batteries could offer higher efficacy compared to the conventional hydrometallurgical lithium recovery, which involves several separation steps for impurity elements. This efficient and flexible approach signifies a notable advancement in purification and separation technology, providing an eco-friendly solution for lithium recovery from spent lithium-ion batteries. This study introduces a viable approach for developing a recycling process for spent lithium-ion batteries that aligns with the ultimate goal of achieving carbon neutrality.

Selective recovery of lithium from spent lithium iron phosphate batteries using oxidation pressure sulfuric acid leaching system

Selective Recovery of Lithium, Iron Phosphate and Aluminum from Spent Lifepo4 Batteries Using a Combination of Leaching and Magnetically Assisted Separation

High-power ultrasound facilitation of the generality for LiFePO4 regeneration

With the increasing use of electric vehicles, the demand for lithium iron phosphate batteries (LiFePO4) has risen sharply. Therefore, the recycling of metals from these batteries at the end of their life is necessary. In this study, a hydrometallurgical process for the recovery of lithium phosphate from spent LiFePO4 batteries was developed. The effects of the parameters on the recovery process, consisting of leaching, solvent extraction, and precipitation were investigated. The addition of H2O2 to the H2SO4 solution was ineffective for the selective leaching of Li(I) over iron. The results showed that Li(I) and iron were completely dissolved by 1.5 mol/L H2SO4, 100 g/L pulp density at 25 ?C for 60 min at 300 rpm. After oxidation of Fe(II) in the leaching solution by addition of H2O2, Fe(III) was completely separated from the solution by five steps of cross-flow extraction with 1.0 mol/L D2EHPA at room temperature. The loaded Fe(III) was successfully separated by four steps of cross-current stripping with 50% (v/v) aqua regia solution. Finally, most Li(I) was recovered by precipitation of lithium phosphate from the iron-free raffinate by maintaining the pH of the solution at 11 and the temperature at 95 ?C for 30 min. The optimum conditions for the complete dissolution of LiFePO4 batteries by sulfuric acid solution and for the separation of iron and lithium ions from the leaching solutions were determined. A hydrometallurgical process was proposed for the recovery of pure lithium phosphate from spent LiFePO4 batteries.

A simple green method for in-situ selective extraction of Li from spent LiFePO4 batteries by synergistic effect of deep-eutectic solvent and ozone

A perspective on the recovery mechanisms of spent lithium iron phosphate cathode materials in different oxidation environments

Synergistic carbon-sulfur co-roasting driven sustainable and selective recovery of lithium from spent ternary lithium-ion batteries.

Gas evolution characterization and phase transformation during thermal treatment of cathode plates from spent LiFePO4 batteries

This study investigated the gaseous products evolution behaviors and the recovery performance of cathode materials from spent LiFePO4 batteries by vacuum pyrolysis. The thermogravimetric-differential scanning calorimetry analysis coupled with electron ionization mass spectrometry (TG-DSC-EI-MS) results indicated that inorganic gases (H2O, CO, CO2), alkane gases (CH4, C2H4, C2H6, CH3OH, C3H6, C3H4O3, C4H8O3), and fluoride-containing gases (HF, OPF3, C2H2F2) were the resulting gaseous products in the vacuum pyrolysis of cathode materials. At the same time, the gaseous product species and relative yield were significantly affected by pyrolysis temperature. Combined with the GC-MS analysis of pyrolysis tar obtained from vacuum pyrolysis simulation experiments, it could be inferred that pyrolysis tar was formed as a result of the cleavage and recombination of chemical bonds in solvents. The simulation experiments also showed that the increase of vacuum pyrolysis temperature and decrease of residual gas pressure enhanced the recovery efficiency of cathode materials. Further, the carbon and fluorine content of the cathode materials were found to decrease slowly during vacuum pyrolysis, while the aluminum content increased. When the vacuum pyrolysis temperature was above 600 °C, Al foils ablated and even melted to strips. The phase composition of cathode materials was still LiFePO4 after vacuum pyrolysis. The leaching performance tests of cathode materials demonstrated that the increase of vacuum pyrolysis temperature and decrease of residual gas pressure can lead to the decrease of leaching efficiency for Fe. This technology offers an efficient way to recycle organic compounds and valuable materials from spent LiFePO4 batteries, and it has been demonstrated to be of good economic benefit and energy savings.

A green process for phosphorus recovery from spent LiFePO4 batteries by transformation of delithiated LiFePO4 crystal into NaFeS2