A sustainable process for selective recovery of lithium as lithium phosphate from spent LiFePO4 batteries

et al. 2023

Ind. Eng. Chem. Res.

To develop efficient, viable, and promising routes to regenerate nano-LiFePO4 (nano-LFP) composite materials from spent LFP batteries, this paper studied phosphate approaches by taking Li3PO4 and FePO4 as raw materials. The crystalline structure, morphology, and physicochemical properties of regenerated LiFePO4 nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical measurement. Regenerated LiFePO4 owned a good olivine structure with a space group of Pnma. After being coated with carbon, rectangular-structured LiFePO4 prepared by hydrothermal synthesis exhibited high specific capacity, excellent rate capability, and good Li+ diffusivity. When the pH value was around 8.0 and the amount of the Li3PO4 raw material was 14 mmol, the discharge capacity at 0.1C was 158.6 mAh g–1 and the capacity retention rate was 99.19% at 1C after 300 cycles. Meanwhile, flake-like LiFePO4/C synthesized by the carbothermal method at 700 °C and a 14 wt % carbon mass fraction showed an initial discharge capacity of 159.0 mAh g–1 at 0.1C and a capacity retention rate of 97.45% after 300 cycles at 1C, exhibiting excellent electrochemical performance. Overall, this study provides a facile, feasible, and sustainable recovery method for the battery industry for recovering phosphate products from spent LFP cathode materials and subsequent large-scale regeneration of LiFePO4 composite materials.

Section: Introductionmentioning

confidence: 99%

Green Phosphate Route of Regeneration of LiFePO₄ Composite Materials from Spent Lithium-Ion Batteries

et al. 2023

Ind. Eng. Chem. Res.

“…At present, the recovery of cathode materials from lithium-ion batteries is mainly accomplished by leaching metals into a solution using organic or inorganic acids, followed by recovering metal ions in the solution [11]. Commonly used inorganic acids include sulfuric acid [12], hydrochloric acid [13], and phosphoric acid [14], while organic acids include citric acid [15], formic acid [16], and oxalic acid [17]. In order to make the leaching process easier and more efficient, Pourbaix plots can be thermodynamically predicted and used to determine the appropriate parameters to be employed in the leaching process [18].The metal ions in the solution can be recovered by adding a precipitant [19,20], but the precipitation reactions make it difficult to obtain only the target metal because it will coprecipitate with other metal salts [21].…”

Section: Introductionmentioning

confidence: 99%

Recovery of Li, Mn, and Fe from LiFePO4/LiMn2O4 mixed waste lithium-ion battery cathode materials

et al. 2023

J min metall B Metall

The recovery of metals from used lithium-ion battery cathode materials is of both environmental and economic importance. In this study, acid leaching stepwise precipitation was used to separate and recover lithium, iron, and manganese from the mixed cathode material LiFePO4/LiMn2O4. The thermodynamic characteristics of lithium, iron, and manganese metal phases, especially the stability region, were analyzed by Eh-pH diagrams. The sulfuric acid and hydrogen peroxide leaching system released Fe3+, Mn2+, and Li+ ions from the cathode material. Fe3+ in the leaching solution was precipitated as Fe(OH)3 and finally recovered as Fe2O3 after calcination. Mn2+ in the leaching solution was recovered as MnCO3. The remaining Li+-rich solution was evaporated and crystallized into Li2CO3. The purity of the recycled products MnCO3 and Li2CO3 met the standard of cathode materials for lithium-ion batteries. XRD and XPS analysis showed that the main phase in the leaching residue was FePO4. This process can be used to separate and recover metals from mixed waste lithium-ion battery cathode materials, and it also provides raw materials for the preparation of lithium-ion battery cathode materials.

“…The development of the electric vehicle industry is being vigorously encouraged in China. , China is increasingly reliant on electric vehicles, and the pace of electric vehicle development in China has staggeringly shifted from 29.8 GW h in 2015 to 79.2 GW h in 2020 . Due to lithium iron phosphate (LFP) batteries having outstanding thermal stability, high safety performance, excellent cycling performance, and low material cost, they are widely used in electric vehicles and hybrid vehicles. − However, after 500–2000 cycles of charge and discharge, the internal structure of the LFP batteries will change irreversibly, blocking the channel of Li + diffusion, and ultimately leading to the decommission of LFP batteries. − The global electric vehicle inventory is expected to reach 145 million by 2030. The number of the spent LFP batteries will exceed 11 million tons .…”

Section: Introductionmentioning

confidence: 99%

Advanced Solid-State Electrolysis for Green and Efficient Spent LiFePO₄ Cathode Material Recycling: Prototype Reactor Tests

Huang

et al. 2022

Ind. Eng. Chem. Res.

Spent lithium iron phosphate (LFP) battery recycling has to avoid excessive reagent cost and secondary pollution, such as waste acid. This research proposed a solid-state electrolysis method to reduce reagent cost and wastewater amount. This method was similar to the discharge mechanism of the lithium-ion battery, which innovatively adopted solid-state electrode reactions to leach Li and Fe into the phosphoric acid electrolyte. Meanwhile, several key performance indicators of such electrolyzers were evaluated. The time-space yield of the solid-state electrodes reached 108.17 g m–2 h–1. The leaching efficiency of Li and Fe reached 98.23 and 96.06%, respectively, with electric energy consumption of only 578.15 kW h per ton spent LFP cathode materials. The apparent leaching kinetics analysis determined the control step of the Li and Fe leaching process. The recovery rates of Li and Fe were 93.51 and 97.96%, respectively. Battery-grade FePO4 and Li3PO4 products were derived, which were directly employed for LiFePO4 reproduction. With further evaporation to prepare NH4H2PO4, there was no waste water in all processes of this novel recycling method. This study demonstrates the possibility of green and efficient spent LFP recovery and contributes to environmental protection and sustainable development of resources.