Efficient separation and selective Li recycling of spent LiFePO4 cathode
Abstract
Given the fast-growing demand for lithium-ion batteries (LIBs) and the upcoming climax of LIB retirement, efficient recycling of spent LIBs has shown increasing importance in both economic benefit and environmental conservation. The LIBs with LiFePO4 (LFP) cathodes account for half of the LIB market, so developing an appropriate recycling way for spent LFP (SLFP) batteries is imperative. In this work, a closed-loop regeneration of SLFP cathodes is proposed, in which a facile cold stimulation route is invented to peel the SLFP layer from Al foil, and then Li and Fe elements are selectively and efficiently extracted from the peeling SLFP layer under mild conditions based on an oxidant of NaClO. The leaching rate of elemental Li could reach 98.3%, and the regenerated LFP synthesized by recovered Li2CO3 and FePO4 shows exceptional performance with a discharge capacity of 162.6 mAh g-1 at 0.5 C. This regeneration route has greatly reduced the use of chemical reagents, shortened the process of impurity removal, and, therefore, realized the closed-loop regeneration of SLFP batteries.
Keywords
INTRODUCTION
Since their commercial application in the 1990s, lithium-ion batteries (LIBs) have been widely used in portable electronics and electric vehicles and in the upcoming blowout era of large-scale electrical energy storage[1-3]. The installed capacity of LIBs has increased from 64.3 GWh in 2017 to 432.7 GWh in 2022 and may exceed 6,500 GWh by 2050[4]. LiFePO4 (LFP), one of the most widely used cathode materials for LIBs, accounts for half of the LIB market. Owing to the strong energy of Fe-O and P-O bonds, the olivine crystal structure of LFP can be well maintained during the repeated lithiation/delithiation cycles, resulting in a long cycle life and good high-temperature stability of the LFP batteries[5,6]. The service life of a LFP battery is generally 5-8 years, and the next few years will be the climax of LFP battery retirement[7]. A large number of spent lithium iron phosphate (SLFP) batteries will soon pose serious environmental and social issues[8]. Therefore, developing an appropriate recycling way for SLFP batteries is a matter of great urgency.
The cathode materials contain Li and other valuable transition-metal elements, accounting for 50% of the cost of LIBs. Therefore, the recycling of spent LIBs mainly concentrates on the recovery and reuse of the cathode materials, which has obvious socioeconomic and environmental benefits[9]. For the SLFP cathode, there are two main recycling routes currently: pyrometallurgy and hydrometallurgy[10,11]. The pyrometallurgy route enriches the precious metal elements or renovates the materials via high temperature treatment[12,13]. As a traditional recovery method, pyrometallurgy is simple to operate and can be adapted to a variety of cathode materials. However, the high temperature process can lead to partial lithium loss, lowering the extraction rate of Li (< 90%)[14]. Moreover, the high-temperature process consumes vast energy and emits large quantities of greenhouse gases, so it is not a sustainable industrial production method[15]. By comparison, hydrometallurgy has advantages of high recovery efficiency, low energy consumption, and limited gas emission[16,17]. But in most of the hydrometallurgy processes, strong inorganic acid or organic acid are usually used to destroy the structure of the cathode materials and extract Li and other valuable metal elements[18-20]. Kumar et al. have proposed an organic acid-based leaching strategy to recover SLFP cathodes, in which the leaching rates of Li, Cu, and Al reach 94.83%, 96.92%, and 47.24%, respectively[18].
Peeling the cathode materials from the Al foil precisely and low-costly has great significance for the following material recovery[30]. At present, two main stripping methods have been used. One is to directly dissolve the Al foil with acid or alkali, realizing the separation of the cathode materials and Al foil[31,32]. The other is to make the binder (polyvinylidene fluoride, PVDF) invalid through heat treatment or organic solvent immersion so that the cathode materials fall off from the Al foil[33,34]. The extensive use of acid, alkali, and organic solvents increases the cost of recovery and also brings serious secondary pollution[35]. More importantly, the content of Al impurities in the cathode materials obtained by these stripping methods is often high[36]. To achieve high-quality recycling or recovery, a further impurity removal process is required, leading to a longer recovery process and loss of valuable metals.
Herein, a closed-loop regeneration of SLFP cathodes is proposed, in which a facile cold stimulation method is invented to peel the SLFP layer from Al foil, and then Li and Fe are selectively and efficiently extracted from the peelings under mild conditions based on an oxidant of NaClO [Figure 1]. The cold stimulation stripping process does not require any chemical reagents, which controls the cost of reagents and the chemical pollution from the source. Meanwhile, this method effectively reduces the content of Al impurities in the stripped cathode material, which is conducive to the following extract of Li. Furthermore, via the oxidation of NaClO, Fe2+ is oxidized to Fe3+ as FePO4 precipitation, and Li is extracted from the crystal and converted into soluble lithium salts. A saturated Na2CO3 solution is further added to precipitate Li as
Figure 1. Schematic illustration of the recycling route for the SLFP cathode.
EXPERIMENTAL SECTION
Materials and reagents
The SLFP batteries were obtained from Guangzhou Energy Very Endure Co., Ltd, China. NaClO solution (Available chlorine 12%), Na2CO3, HCl, NaOH, and sucrose were purchased from Aladdin Reagent Co., Ltd (Shanghai, China). All the chemical reagents used in this work were of analytical grade.
Experimental procedures
Stripping of SLFP cathodes
After discharging below 3.0 V, the SLFP batteries were disassembled in the glove box. The obtained SLFP cathode sheets were cut into small pieces with 1 cm. The small pieces were put into a 25 mL beaker with
Selective leaching of Li and Fe
All leaching experiments were carried out in a 500 mL beaker, with a magnetic stirrer heating and stirring. Firstly, a 5 g stripped SLFP layer was mixed with deionized water in the beaker with different solid-liquid ratios. Then, a certain volume of NaClO solution (pH = 11) was added. The pH of the reaction system was adjusted with a small amount of hydrochloric acid, and the oxidation leaching reaction was conducted at magnetic stirring of 300 r min-1. In this process, Li was selectively leached into the solution, and Fe2+ was oxidized to Fe3+ as FePO4 precipitation. At the same time, due to the oxidation of NaClO, the PVDF binder failed, and conductive carbon was released. Low-density conductive carbon floated on the upper layer of the solution, which was collected first. Then, via vacuum filtration, Li+ solution and FePO4 precipitation were obtained. The FePO4 precipitation was washed with deionized water three times and was used as a precursor for RLFP after drying. The pH of the Li+ solution was adjusted to 13 with NaOH solution, and then saturated Na2CO3 solution was added to obtain white Li2CO3 precipitation after heating and boiling for
In order to optimize the leaching conditions, the reaction time (0.5-3.0 h), temperature (20-40 °C), system pH (1-9), solid-liquid ratio (10-100 g L-1), and NaClO dosage (NaClO:SLFP = 0.85:1.05) were systematically investigated. After the leaching reaction, the content of Li, P, Fe, and Al in the solution was measured by ICP-OES. The leaching efficiency of each element is calculated using the formula reported in the literature:
where R represents the leaching rate of the target element (%), C represents the concentration of the target element in the solution (g L-1), V represents the volume of the solution (V), m represents the mass of the stripped cathode materials participating in the reaction (g), and ω% represents the mass proportion of the target element in the stripped cathode materials[37].
Regeneration of LiFePO4
The recovered Li2CO3 and FePO4 were mixed at a molar ratio of 1.05:1, and 10 wt% sucrose was added as the carbon source. Ethanol was added as a dispersant, and the mixture was ball milled for 5 h at a speed of
Characterization
The morphology and crystal structure were observed on Quanta650 FEG scanning electron microscope (FEI, America) and JEM-F200 HR-TEM (JEOL, Japan). X-ray diffraction (XRD) patterns were analyzed by XRD-6100 (Shimadzu, Japan). Fourier-transform infrared (FT-IR) spectrum was conducted by a Spectrum one FT-IR spectrophotometer (Thermo Scientific Nicolet iS20, America). X-ray photoelectron spectroscopy (XPS) was performed with an AXIS-ULTRA DLD-600W spectrometer (Kratos, Japan). The concentration of elements was analyzed by Agilent 730 ICP-OES (PerkinElmer, America).
The regenerated cathodes were made by mixing the RLFP powder, PVDF binder, and super P in a ratio of 9:0.5:0.5 with N-methyl pyrrolidone (NMP) as the solvent to get slurry. Then, the mixed slurry was uniformly coated on the Al foil and dried at 100 °C for 12 h. The half-cells were assembled with the RLFP cathode, lithium metal anode, and electrolyte in an Ar-filled glove box. The electrolyte was 1 M LiPF6 in an equal mixture of ethyl carbonate (EC) and diethyl carbonate (DEC). The relative electrochemical performances, such as rate capability and cycling stability, of RLFP and SLFP were recorded in a voltage window of 2.5-4.2 V using a Land battery test system (MIHW-200-160CH). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed using an electrochemical workstation
RESULTS AND DISCUSSION
Stripping of SLFP cathodes
The closed-loop regeneration route based on the cold stimulation peeling and NaClO oxidative extraction is illustrated in Figure 1 and Supplementary Figure 1. The strong adhesive strength of PVDF makes it difficult to separate Al and cathode materials completely. The traditional reagent dissolution method is expensive and may bring high content Al impurities in the stripped cathode materials. Here, the cold stimulation route is cheap and environmentally friendly. Figure 2A and E shows images of the untreated SLFP cathode, and Figure 2C shows the section. It can be seen that the cathode material is closely connected to the Al foil, and the electrode surface is dense and uniform. During the freeze-drying process, the SLFP layer is separated from the Al foil [Supplementary Figure 2A]. The glass transition temperature of PVDF ranges from -20 °C to -40 °C so that the long chains of PVDF will break and fail during the freeze-drying process[38]. The SEM images in Figure 2D and F show that the cathode layer separates with the Al foil, and the stripped layer becomes loose and porous. As shown in Figure 2B, the Al foil, after the cold stimulation stripping, is clean and smooth. Supplementary Figure 2C and D compares the SEM images of recycled Al foil and commercial Al foil. Obviously, there is no corrosion on the surface of the recovered Al foil. The XRD spectra in Supplementary Figure 2B show the diffraction peaks of the recovered Al foil agree well with those of the commercial Al foil [Supplementary Figure 2B]. The ICP-OES result shows that the Al impurity content is only 0.03% in the stripped SLFP cathode layer, which could be ignored [Supplementary Table 1]. Obviously, the cold stimulation route controls the Al impurity from the source, which simplifies the post processing efficiently.
Figure 2. (A and B) digital photos of SLFP cathodes and Al foil. (C and D) Cross-section SEM images of SLFP cathodes and SLFP cathodes after freeze drying. (E and F) SEM images of SLFP cathodes and peeling SLFP layers.
Leaching mechanism
As a cheap oxidant, NaClO is widely used as a bleaching agent in the industries of daily-use chemicals, papermaking, and water treatment. In this work, it was selected to leach the peeling SLFP layer via an oxidizing way. Without NaClO addition, the peeling SLFP layer was treated with ultrapure water under the same reaction conditions for comparison. No change can be observed, and no Li and Fe can be detected in the leaching solution [Supplementary Table 2]. As NaClO is added, a black granular floating substance rises. The XRD analysis shows that the floating mixture is mainly C [Supplementary Figure 3A]. Via ICP-OES analysis, the Li content in the leaching solution is identified as 1,062.48 mg L-1, and the Fe content is
ClO- + 2H+ + 2LiFePO4 = 2FePO4 + 2Li+ + H2O + Cl-.
By adding saturated Na2CO3 solution into the Li leaching solution, white Li2CO3 powder is obtained, identified by XRD analysis [Figure 3A]. The SEM images in Figure 3B demonstrate that the obtained Li2CO3 has a rod-like structure. The solid precipitate at the bottom is orthogonal FePO4 (JCPDS: 37-0478, Figure 3C), which has no impurity. The SEM and element mapping analysis [Figure 3D-F] show the FePO4 particles are uniform, and the P, Fe, and O elements are evenly distributed. The regenerated FePO4 is directly used as the precursor for the following RLFP preparation.
Figure 3. (A and B) XRD characterization patterns and SEM images of recycled Li2CO3. (C) XRD characterization patterns of recycled FePO4. (D and E) SEM images of recycled FePO4. (F) EDS mapping of recycled FePO4 [corresponding to (D)].
Optimization of leaching conditions
The dosage of NaClO, reaction temperature, reaction time, pH of the system, and solid-liquid ratios were systematically optimized. Figure 4A shows the leaching efficiency of each element at different NaClO dosages. When the molar ratio of NaClO to SLFP reaches 1:1, the leaching rate of Li is up to 98.3%, and the leaching rate of iron can be ignored, indicating that the selective separation of Li and Fe has been achieved. The leaching efficiency of Li declines when the molar ratio of NaClO to SLFP reaches 1.05:1. This is due to the decomposition of NaClO at higher concentrations. From Figure 4B, it can be seen the leaching rate of Li reaches its highest at 30 °C and declines as temperature further increases. The latter drop can be ascribed to the accelerated decomposition rate of NaClO, which results in an incomplete leaching reaction. Figure 4C shows that Li reaches saturation in the solution after 2 h. Figure 4D shows the leaching rate increases with the decrease of pH. However, strong acidity leads to the dissolving of FePO4. Therefore, the pH of the system is controlled at 2 finally. At last, the solid-liquid ratio is evaluated from 10 g L-1 to 100 g L-1. As shown in Figure 4E, the optimal solid-liquid ratio is 50 g L-1. After optimization, the leaching rate of Li reaches 98.3%; the leaching rate of Fe is only 0.11%, and the Al content in the solution is nearly 0%. So, the overall leaching efficiencies of both Fe and Al are low, which has little impact on the final Li extraction.
Figure 4. The effects of (A) the mole ratio of NaClO and SLFP, (B) reaction temperature, (C) reaction time, (D) pH of the system, and (E) S/L ratio on leaching efficiencies of Li, P, Fe, and Al.
Kinetics analysis
To grasp the characteristics of the NaClO reactions, the kinetic model was evaluated. The oxidation reaction is considered as the rate control step in the whole leaching process. The formation of FePO4 layers in the oxidation process conforms to the typical shrinking core model, including external diffusion, internal diffusion, and chemical reaction[39]. Under certain conditions, they can act as a control step of the leaching reaction respectively. Based on the optimal leaching condition, the relations of the Li leaching efficiency with reaction temperatures (20 °C, 25 °C, 30 °C, 40 °C) and time (0-3 h) were recorded. Detailed descriptions and data were provided in Supplementary Text 1 and Supplementary Tables 3-6. As mentioned in Figure 5A, with temperature increasing, the leaching efficiency of Li rises at first and then falls. To determine the rate control step, kinetics fitting for external diffusion, internal diffusion, and chemical reaction is performed according to the corresponding kinetic equations [Supplementary Table 7]. Figure 5B shows the linear correlation coefficient R2 of internal diffusion is 0.999 at 30 °C, which is much higher than the linear correlation coefficient R2 (0.966) of external diffusion and the linear correlation coefficient R2 (0.980) of a chemical reaction. Similarly, at other temperatures, the R2 of internal diffusion [Figure 5C] is also the highest one among the steps [Supplementary Figure 4]. Therefore, it can be speculated that the internal diffusion process of the oxidant is more critical than the other two steps, which is the control step during the whole leaching reaction. According to the Arrhenius equation [Supplementary Text 2], the relationship between ln k and 1000/T is shown in Figure 5D, and the correlation coefficient is high
Figure 5. (A) The leaching efficiency of Li+ at different temperatures varies with time. (B) Kinetics fitting diagram of different leaching models at 30 °C. (C) Kinetics fitting result of internal diffusion at different temperatures varies with time. (D) Arrhenius diagram of ln k-1000/T based on the rate control step.
Regeneration of LiFePO4
The recovered Li2CO3 and FePO4 were used to synthesize RLFP directly. Figure 6A and B shows the morphology of the obtained RLFP. Compared with the commercial LFP (CLFP)
Figure 6. (A and B) SEM images of RLFP. (C) EDS mapping of RLFP [corresponding to (A)] (D) HRTEM images of RLFP nanoparticles. (E) XRD characterization patterns of SLFP and RLFP. (F) XPS spectra of Fe 2p in RLFP and SLFP.
Electrochemical performances
The electrochemical performances of SLFP and RLFP were compared. Figure 7A shows the CV curves of RLFP and SLFP from 2.5 to 4.2 V at a scanning rate of 0.1 mV s-1. The cathodic and anodic peaks of RLFP are 3.58 V and 3.29 V, respectively, corresponding to the Fe2+/Fe3+ redox reaction. The potential intervals of RLFP (0.29 V) are much smaller than that of SLFP (0.48 V), and the peak intensity of RLFP is higher, indicating that RLFP has smaller polarization and better electrochemical activity. The charge/discharge voltage plateau gap of RLFP in Figure 7B is narrower than that of SLFP, which agrees well with the CV result. The initial reversible specific capacity of RLFP is 162.6 mAh g-1, much higher than that of SLFP
Figure 7. (A) Cyclic voltammetry and (B) the initial charge/discharge curves of SLFP and RLFP. (C) The charge/discharge profiles for RLFP at different rates. (D) Rate performance and (E) long-term cycling stability at 0.5 C for 300 cycles of SLFP, RLFP, and CLFP.
The lithium-ion diffusion coefficients (DLi+) of RLFP and SLFP were analyzed by an EIS test. The Nyquist plots are shown in Supplementary Figure 7A, in which the semi-circle indicates the charge transfer resistance (Rct), and the straight line relates to the Li+ diffusion process. Obviously, the Rctof the RLFP
CONCLUSIONS
In summary, the closed-loop regeneration route based on the cold stimulation peeling combined with NaClO oxidation separation has three clear advantages. Firstly, the overall process does not involve much strong acid or base, so it is quite environmentally friendly. Secondly, the simple cold stimulation process realizes a negligible Al impurity in the stripped cathode material, which greatly simplifies the subsequent impurity removal process. Finally, the oxidation process based on NaClO realizes the selective separation of Li and Fe efficiently. The leaching rate of Li could reach 98.3%, and the RLFP synthesized by recovered
DECLARATIONS
Authors’ contributions
Methodology, investigation, and writing manuscript: Kong Y
Project administration and funding acquisition: Yuan L
Analyzed the data: Liao Y
Discussed the whole paper: Shao Y
Performed the measurements: Hao S
Conceptualization and supervision: Huang Y
Availability of data and materials
The data supporting our work can be found in the Supplementary Materials.
Financial support and sponsorship
This work was supported by the National Natural Science Foundation of China (Grant No. 22075091) and the Natural Science Foundation of Hubei Province (Grant No. 2021CFA066).
Conflicts of interest
All authors declared that there are no conflicts of interest.
Ethical approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Copyright
© The Author(s) 2023.
Supplementary Materials
REFERENCES
1. Liu H, Strobridge FC, Borkiewicz OJ, et al. Capturing metastable structures during high-rate cycling of LiFePO4 nanoparticle electrodes. Science 2014;344:1252817.
2. Yan Y, Zeng T, Liu S, Shu CZ, Zeng Y. Lithium metal stabilization for next-generation lithium-based batteries: from fundamental chemistry to advanced characterization and effective protection. Energy Mater 2023;3:300002.
3. Wu F, Maier J, Yu Y. Guidelines and trends for next-generation rechargeable lithium and lithium-ion batteries. Chem Soc Rev 2020;49:1569-614.
4. Miao Y, Liu L, Zhang Y, Tan Q, Li J. An overview of global power lithium-ion batteries and associated critical metal recycling. J Hazard Mater 2022;425:127900.
5. Fan MC, Zhao Y, Kang YQ, et al. Room-temperature extraction of individual elements from charged spent LiFePO4 batteries. Rare Met 2022;41:1595-604.
6. Zhang B, He Y, Gao H, et al. Unraveling the doping mechanisms in lithium iron phosphate. Energy Mater 2022;2:200013.
7. Ciez RE, Whitacre JF. Examining different recycling processes for lithium-ion batteries. Nat Sustain 2019;2:148-56.
8. Nanda S, Berruti F. Municipal solid waste management and landfilling technologies: a review. Environ Chem Lett 2021;19:1433-56.
9. Gangaja B, Nair S, Santhanagopalan D. Reuse, recycle, and regeneration of LiFePO4 cathode from spent lithium-ion batteries for rechargeable lithium- and sodium-ion batteries. ACS Sustain Chem Eng 2021;9:4711-21.
10. Song X, Hu T, Liang C, et al. Direct regeneration of cathode materials from spent lithium iron phosphate batteries using a solid phase sintering method. RSC Adv 2017;7:4783-90.
11. Zhao Y, Yuan X, Jiang L, et al. Regeneration and reutilization of cathode materials from spent lithium-ion batteries. Chem Eng J 2020;383:123089.
12. Makuza B, Tian Q, Guo X, Chattopadhyay K, Yu D. Pyrometallurgical options for recycling spent lithium-ion batteries: a comprehensive review. J Power Sources 2021;491:229622.
13. Holzer A, Windisch-kern S, Ponak C, Raupenstrauch H. A novel pyrometallurgical recycling process for lithium-ion batteries and its application to the recycling of LCO and LFP. Metals 2021;11:149.
14. Liu F, Peng C, Porvali A, Wang Z, Wilson BP, Lundström M. Synergistic recovery of valuable metals from spent nickel-metal hydride batteries and lithium-ion batteries. ACS Sustain Chem Eng 2019;7:16103-11.
15. Jin S, Mu D, Lu Z, et al. A comprehensive review on the recycling of spent lithium-ion batteries: urgent status and technology advances. J Clean Prod 2022;340:130535.
16. Yao Y, Zhu M, Zhao Z, Tong B, Fan Y, Hua Z. Hydrometallurgical processes for recycling spent lithium-ion batteries: a critical review. ACS Sustain Chem Eng 2018;6:13611-27.
17. Jung JC, Sui P, Zhang J. A review of recycling spent lithium-ion battery cathode materials using hydrometallurgical treatments. J Energy Stor 2021;35:102217.
18. Kumar J, Shen X, Li B, Liu H, Zhao J. Selective recovery of Li and FePO4 from spent LiFePO4 cathode scraps by organic acids and the properties of the regenerated LiFePO4. Waste Manag 2020;113:32-40.
19. Yue XH, Zhang CC, Zhang WB, Wang Y, Zhang FS. Recycling phosphorus from spent LiFePO4 battery for multifunctional slow-release fertilizer preparation and simultaneous recovery of Lithium. Chem Eng J 2021;426:131311.
20. Qiu HJ, Hao XD, Gui YX, Liu XT, Chen G, Gao L. Recent progresses in recycling technology for cathode materials from spent lithium iron phosphate batteries. Modern Chem Ind 2022;42:60-4, 69.
21. Ji G, Ou X, Zhao R, et al. Efficient utilization of scrapped LiFePO4 battery for novel synthesis of Fe2P2O7/C as candidate anode materials. Resour Conserv Recycl 2021;174:105802.
22. He K, Zhang ZY, Zhang FS. A green process for phosphorus recovery from spent LiFePO4 batteries by transformation of delithiated LiFePO4 crystal into NaFeS2. J Hazard Mater 2020;395:122614.
23. Dai Y, Xu Z, Hua D, Gu H, Wang N. Theoretical-molar Fe3+ recovering lithium from spent LiFePO4 batteries: an acid-free, efficient, and selective process. J Hazard Mater 2020;396:122707.
24. Yang Y, Zheng X, Cao H, et al. A closed-loop process for selective metal recovery from spent lithium iron phosphate batteries through mechanochemical activation. ACS Sustain Chem Eng 2017;5:9972-80.
25. Peng D, Zhang J, Zou J, et al. Closed-loop regeneration of LiFePO4 from spent lithium-ion batteries: a “feed three birds with one scone” strategy toward advanced cathode materials. J Clean Prod 2021;316:128098.
26. Li H, Xing S, Liu Y, Li F, Guo H, Kuang G. Recovery of lithium, iron, and phosphorus from spent LiFePO4 batteries using stoichiometric sulfuric acid leaching system. ACS Sustain Chem Eng 2017;5:8017-24.
27. Yu J, Wang X, Zhou M, Wang Q. A redox targeting-based material recycling strategy for spent lithium ion batteries. Energy Environ Sci 2019;12:2672-7.
28. Du H, Kang Y, Li C, et al. Easily recyclable lithium-ion batteries: recycling-oriented cathode design using highly soluble LiFeMnPO4 with a water-soluble binder. Battery Energy 2023;2:20230011.
29. Xu J, Jin Y, Liu K, et al. A green and sustainable strategy toward lithium resources recycling from spent batteries. Sci Adv 2022;8:eabq7948.
30. Liu H, Zhang JL, Liang GQ, Wang M, Chen YQ, Wang CY. Selective lithium recovery from black powder of spent lithium-ion batteries via sulfation reaction: phase conversion and impurities influence. Rare Met 2023;42:2350-60.
31. Fan E, Li L, Wang Z, et al. Sustainable recycling technology for Li-ion batteries and beyond: challenges and future prospects. Chem Rev 2020;120:7020-63.
32. Li L, Fan E, Guan Y, et al. Sustainable recovery of cathode materials from spent lithium-ion batteries using lactic acid leaching system. ACS Sustain Chem Eng 2017;5:5224-33.
33. Jing Q, Zhang J, Liu Y, Zhang W, Chen Y, Wang C. Direct regeneration of spent LiFePO4 cathode material by a green and efficient one-step hydrothermal method. ACS Sustain Chem Eng 2020;8:17622-8.
34. Liu K, Zhang FS. Innovative leaching of cobalt and lithium from spent lithium-ion batteries and simultaneous dechlorination of polyvinyl chloride in subcritical water. J Hazard Mater 2016;316:19-25.
35. Ji Y, Jafvert CT, Zyaykina NN, Zhao F. Decomposition of PVDF to delaminate cathode materials from end-of-life lithium-ion battery cathodes. J Clean Prod 2022;367:133112.
36. Widijatmoko SD, Fu G, Wang Z, Hall P. Recovering lithium cobalt oxide, aluminium, and copper from spent lithium-ion battery via attrition scrubbing. J Clean Prod 2020;260:120869.
37. Xu Y, Qiu X, Zhang B, et al. Start from the source: direct treatment of a degraded LiFePO4 cathode for efficient recycling of spent lithium-ion batteries. Green Chem 2022;24:7448-57.
38. Hronsk V, Jozef M. Thermally stimulated depolarization and mechanical relaxation study of glass transition in polyvinylidene fluoride. Acta Phys Slovaca 2002;52:91-100. Available from: https://www.researchgate.net/publication/256086873 [Last accessed on 8 Nov 2023]
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Kong Y, Yuan L, Liao Y, Shao Y, Hao S, Huang Y. Efficient separation and selective Li recycling of spent LiFePO4 cathode. Energy Mater 2023;3:300053. http://dx.doi.org/10.20517/energymater.2023.57
AMA Style
Kong Y, Yuan L, Liao Y, Shao Y, Hao S, Huang Y. Efficient separation and selective Li recycling of spent LiFePO4 cathode. Energy Materials. 2023; 3(6): 300053. http://dx.doi.org/10.20517/energymater.2023.57
Chicago/Turabian Style
Kong, Yuelin, Lixia Yuan, Yaqi Liao, Yudi Shao, Shuaipeng Hao, Yunhui Huang. 2023. "Efficient separation and selective Li recycling of spent LiFePO4 cathode" Energy Materials. 3, no.6: 300053. http://dx.doi.org/10.20517/energymater.2023.57
ACS Style
Kong, Y.; Yuan L.; Liao Y.; Shao Y.; Hao S.; Huang Y. Efficient separation and selective Li recycling of spent LiFePO4 cathode. Energy Mater. 2023, 3, 300053. http://dx.doi.org/10.20517/energymater.2023.57
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