Mechanochemical Process Enhanced Cobalt and Lithium Recycling

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Mechanochemical Process Enhanced Cobalt and Lithium Recycling from Wasted Lithium-ion Batteries Jie Guan, Yaguang Li, Yaoguang Guo, Ruijing Su, Guilan Gao, Haixiang Song, Hao Yuan, Bo Liang, and Zhanhu Guo ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.6b02337 • Publication Date (Web): 08 Nov 2016 Downloaded from http://pubs.acs.org on November 14, 2016

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ACS Sustainable Chemistry & Engineering

Mechanochemical Process Enhanced Cobalt and Lithium Recycling from Wasted Lithium-ion Batteries Jie Guan1, Yaguang Li1, Yaoguang Guo1,*, Ruijing Su1, Guilan Gao1, 2,*, Haixiang Song3, Hao Yuan1, Bo Liang1, Zhanhu Guo3,*

1

Shanghai Cooperative Center for WEEE Recycling, School of Environmental and Materials Engineering, Shanghai Polytechnic University, Shanghai 201209, China

2

School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China

3

Integrated Composites Laboratory (ICL), Department of Chemical & Bimolecular Engineering, University of Tennessee, Knoxville, TN 37996 USA

*: Corresponding Authors Email:

[email protected] (Y. G.); [email protected] (G. G.)

[email protected] or [email protected] (Z. G.)

1

ACS Paragon Plus Environment


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Abstract Cobalt (Co) and lithium (Li), rare and valuable elements, are mainly used to prepare lithium cobalt oxide (LiCoO2) for applications in lithium-ion batteries (LIBs). Developing an effective method to recover Co and Li from the waste LIBs is of great significance. In the present study, Co and Li were extracted from pure LiCoO2 powders and the extracted cathode materials powders from the waste LIBs after acid dissolution via a mechanochemical reduction process with iron powders. For pure LiCoO2 powders, the effects of Fe to LiCoO2 mass ratio, rotation speed, and mechanochemical reduction time were examined. These parameters influenced positively the extraction of Co, while showed negligible effects on the leaching of Li. The X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses indicated a promoted extraction of Li arising from the reduction of particle sizes, magnification of specific surface area and change of the crystal structure of particles. For high-efficiency leaching of Co by the mechanochemical reduction process with iron powders, X-ray photoelectron spectroscopy (XPS) analysis indicated the changes in the valence state of Co. The actual cathode materials disassembled from the wasted LIBs pretreated by this novel mechanochemical reduction process were also explored. The results indicated that the leaching ratios of Li, Co, Mn and Ni could reach 77.15%, 91.25%, 100% and 99.9%, respectively. This novel mechanochemical process would be of great importance for the recovery of valuable metals from waste LIBs.

Keywords: Valuable Metals, Wasted Lithium-ion Batteries, Mechanochemical Reduction, Hydrometallurgy. 2


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Introduction Lithium-ion batteries (LIBs) have captured increasing attention for around 16 years, and LIBs outperformed nickel-cadmium and nickel metal-hydride rechargeable batteries, owing to excellent features of small size, high power density, no memory effect, long cycle life, high voltage, low self-discharge, etc.1-4 Therefore, LIBs are widely used in a multitude of portable electronics, especially mobile phones, personal computers, cameras, etc.5 As such, the LIBs are expanding their market share in the area of rechargeable batteries. The quantity and weight of LIBs in 2020 can surpass 25 billion units and 500 thousand tons, respectively. 6 With extensive applications of LIBs in portable electronics, it is evident that an ocean of spent LIBs will be produced after the ~1-3 years lifetime service of the LIBs.7 If the spent LIBs are simply disposed, a serious environmental concern of soil contamination would be caused by the leaked organic electrolytes as well as toxic metals (Co, Li, Cu, Mn, Ni, etc.) contained in the LIBs.8 Furthermore, the spent LIBs can be used to recover valuable metals (Co, Li, Mn, Ni, etc.) or their compounds.9 For instance, lithium cobalt oxide (LiCoO2), a shared cathode active material for commercial LIBs, accounts for 27.5 wt% in a quintessential lithium-ion secondary rechargeable battery, with a metal content of 5-20 wt% Co and 5-7 wt% Li.10,11 Therefore, the recovery of the valuable metals, especially Co and Li from the spent LIBs, is considered to be highly desirable. Recently, several studies have been reported for the recycling of Co and Li from the spent LIBs, focusing on pyrometallurgy, hydrometallurgy or bio-hydrometallurgy processes.6,12,13 Compared to the pyrometallurgical technology with the disadvantages of emission of toxic gases and consumption of intensive energy, the bio-hydrometallurgical approach is more favorable, and 3



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involves higher efficiency, lower costs and quite a few industrial requirements.14,15 However, the treatment period of bio-hydrometallurgical process is too long, and the required microbes are arduous to incubate effectively.14,15 By contrast, for the recovery of metals from spent LIBs, the broad hydrometallurgical processes, involving higher metal recovery rates with good purity, low energy consumption and minimal gas emission, are considered to be more superior, and mainly consist of acid leaching, chemical precipitation, chemical displacement reaction, solvent extraction, hydrothermal reaction, crystallization and electrochemical accumulation, etc.6,12,13 Generally, the cathode active materials, separated by a series of pretreatment steps, such as mechanical separation, and thermal processes,10,11 are leached by an acidic solution in order to transfer the target metals into the solution, and followed by the treatment of the acid leachate and final wastes to recover the metals of interest by means of chemical precipitation, chemical displacement, solvent extraction, electrochemical accumulation, etc. As such, acid leaching is a key step for the recovery of valuable metals. The leaching of LiCoO2 from spent LIBs is usually carried out by using inorganic acids, such as sulfuric, hydrochloric and nitric acids as leachants,16-22 among which higher extractions of Co and Li were obtained with the hydrochloric and nitric acids as the leaching media.23 However, for the leaching process of LiCoO2 in the hydrochloric acid media, special antisepticising equipments need to be installed to treat chlorine (Cl2) generating from HCl oxidation, leading to much more recycling cost or serious environmental problems if this kind of equipments is not available.12 Furthermore, the hydrogen peroxide is generally used as a reductant during the acid leaching, for the purpose that additional H2O2 is easy to reduce Co(III) to Co(II) present in the spent LIBs, which are favorably solubilized than the unreduced moieties; otherwise more 4


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concentrated acids are necessary to obtain comparative dissolutions.10,11,22,24 For instances, Lee et al.22 indicated that the leaching efficiency was increased by 45% for Co and 10% for Li in nitric acid leaching process with the addition of H2O2 as a reducing agent, compared with nitric acid leaching process without reducing agents. Moreover, whether H2O2 contained in the nitric acid leaching media or not, high temperature more than 75℃ is needed.12 However, the addition of H2O2 or high temperature might be regarded as promoting or activating processes for nitric acid extraction, and might result in a higher average costs and operational environmental risk. Therefore, an economic and safe recovery process of Co and Li from waste LIBs is highly desirable. The mechanochemical approach has attracted more attention for potential applications in wide ranges based on the triggered physicochemical changes, including phase transformations, structural defects, strain, amorpholization, and even direct reaction under normal temperature and pressure.25 This approach can also make technically feasible the environmental-friendly recycling of metals from some specific wastes, such as cathode ray tube funnel glass,26 tin-doped indium oxide containing waste27,28 and waste fluorescent lamps,29 while significantly improving the recycling efficiency. As aforementioned, with the traditional hydrometallurgical acid leaching of spent LIBs, little extraction of valuable metals can be obtained at room temperature without the addition of other enhanced solvents. Herein, a mechanochemical process to pretreat the spent LIBs might be supposed to a promoting or activating method for nitric acid extraction of valuable metals Co and Li. Therefore, the aim of the present study is to examine the feasibility of mechanochemical process to enhance the acid leaching of Co and Li at room temperature from the spent LIBs. 5



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Metallic iron powders served as grinding aids. Pure lithium cobalt oxide (LiCoO2) powders were selected to study the influences of mechanochemical parameters on the Co and Li extraction, such as Fe/LiCoO2 powders mass ratio, rotational speed, and mechanochemical milling time. The physicochemical changes established by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) gave insights into the mechanism of the mechanochemical method. Ultimately, the actual scrap sample separated and concentrated from the cathode materials in the waste LIBs was examined to verify the behavior of this novel process.

Experimental Materials. Lithium cobalt oxide (LiCoO2, 99.8% metals basis) powder reagent was purchased from Aladdin Industrial Co. Ltd, Shanghai, China. Iron powder (Fe, ≥ 98% in purity), and nitric acid (HNO3, AR) were obtained from Sinopharm Chemical Reagent Co., Ltd, Shanghai, China. Ultrapure water (18.2 MΩ·cm) was used for all the experiments. The spent LIBs were used in the mobile phones which were collected from Samsung Electronics Co. Ltd (The model: AB463446BC and the capacity: 800 mAh).

Experimental procedure and analysis A planetary ball mill (DECO-PBM-V-0.4L, DECO, China) was used for the experiments. Stainless steel pots with a volume of 100 mL and balls with a diameter of 10.0 mm were used as grinding bodies for the ball milling experiments. Prior to each experiment, certain aliquots were transferred to the reactor vessel to obtain the desired amounts. The rotation speed of the planetary disk was set as a certain value and the rotation direction changed automatically every 30 min. After 6


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the milling, all of the samples were collected for characterization as well as acid leaching. To avoid the interference of other substances and exactly elucidate the mechanochemical mechanism, pure LiCoO2 powders were firstly selected to study the influences of mechanochemical parameters on the Co and Li extraction and physicochemical changes established by XRD, SEM and XPS. Ultimately, the leaching of Co and Li in the waste cathode materials from spent LIBs after mechanochemical process was also examined. Prior to mechanochemical treatment, the spent LIBs were pretreated by discharging, dismantling and separating of cathode materials, which were followed by heat treatment to realize the separation of the cathode materials and the aluminum foil, and removal of the polyvinylidene fluoride (PVDF) binder and acetylene black conductive agent. The detailed pretreatment was presented in the Supporting Information (SI). All the batch leaching experiments were performed in 100 mL HNO3 solution with the concentration of 1 mol/L in a conical flask with a 200 mL capacity immersed in a constant temperature bath at 25 ± 2 ℃ under magnetic stirring. Briefly, 0.3 g grounded samples were added into 1 mol/L HNO3 solution. After immersed for 2 h, the samples were centrifuged. 1 mL leaching sample was diluted in a 50 mL colorimetric tube with ultrapure water. After that, the sample solutions were detected with an inductively coupled plasma-atomic emission spectrometry (ICP-AES) instrument (iCAP-6300, THERMO, U.S.). Briefly, the solution was diluted 50 times with ultrapure water before testing. The detection limits of Co and Li were 0.005 and 0.002μ g/mL, respectively. The metal leaching efficiency was calculated according to Eq. 1.

7



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R

C0  V0 100% m  w%

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(1)

where R is the metal leaching efficiency; C0 is the mass concentration of metal ions in the leachate; V0 is the volume of leachate; m is the mass of samples; and w% is the metal mass fraction.

Characterization of the samples Besides the ICP determinations above, the chemical composition changes of the solid samples during the mechanochemical process were also characterized. XRD was conducted using an X-ray Diffractionmeter (D8 ADVANCE, BRUKER-AXS Corporation, Germany) with Cu Kα radiation at a scan speed of 8° (2θ) per minute ranging from of 2θ = 10 - 80°. The SEM observations were carried out on a JSM 6400, JEOL from Japan. XPS was conducted using X-ray photoelectron spectrometry (ESCALAB 250Xi, Thermo-VG Scientific, USA), and operated via monochromatic Al-Ka X-ray source (1486.6 eV) at 150 W.

Results and Discussion Evaluation of the performance of mechanochemical process. To evaluate the performance of the leaching efficiency of the samples, the powders pretreated by the mechanochemical process were tested. The results show that less than 23% of Co and 39% of Li can only be released from pure LiCoO2 powders after leaching for 2 h (Figure 1). However, even leaching for 4 h, only less than 31% of Co and 55% of Li can be extracted (Figure S1), indicating that direct acid leaching is not an effective approach for the extraction of Co and Li. Compared with direct leaching of the raw sample, the Li extraction of both activated sample (pure LiCoO2 pretreatment by milling) and mechanochemical sample (LiCoO2 and Fe with the mass ratio at 1:1 pretreatment by milling) was increased significantly after leaching for 2 h. However, the dissolution of Co from pure LiCoO2 8


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power after ground for 250 min cannot be increased significantly by acid leaching. By comparison, the leaching efficiency of Co was increased to around 80% as the reductive metallic iron was added during the mechanochemical pretreatment process, showing a good performance for extraction of valuable metals.

Figure 1 Extraction of Co and Li from different samples (Raw sample: pure LiCoO2; Activated sample: pure LiCoO2 after ground; Mechanochemical sample: ground samples of LiCoO2 and Fe with mass ratio of 1:1). Conditions: grinding time = 250 min, rotate speed = 650 rpm.

Influence of Fe/LiCoO2 mass ratio. The Fe/LiCoO2 mass ratio was potentially critical for the extraction of Co and Li, since the leaching efficiency changed when the reductive metallic iron was added. Figure 2 shows the leaching efficiency of Li stay almost the same for both the activated sample and the mechanochemical reduction sample of different mass ratios. However, the extraction of Co was increased from 23% to 80% with the addition of Fe, and the maximum dissolution rate of Co (80%) was obtained when the Fe/LiCoO2 mass ratio was above 1:1. When 9



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the Fe/LiCoO2 mass ratios were above 1:1, the leaching of Co was almost constant. Therefore, Fe/LiCoO2 mass ratio of 1:1 was chosen to explore the subsequent research.

Figure 2 Influence of Fe/LiCoO2 mass ratio on Co and Li leaching. Conditions: grinding time = 250 min, rotate speed = 650 rpm.

Influence of rotating speed. Figure 3a represents the leaching rates of the Co and Li dissolved from the powders ground at different rotation speeds. In milling process conducted by the planetary ball mill, different rotation speeds provided different energies, which significantly affected the reaction rate of the mechanochemical reduction. The extraction of Co increased with increasing the rotation speed, and around 80% Co was obtained at rotation speeds over 450 rpm. However, the Li extraction was not increased significantly, and this might be related to the crystal structure change. Figure 3b demonstrates the dramatic change of crystal structure of the ground sample powders. The results show that the XRD pattern intensity decreased and the full width at half10


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maximum (FWHM) of all peaks was also broadened with the increase of rotation speed, and ultimately the peaks of LiCoO2 disappeared.

Figure 3 Influence of rotate speed on Co and Li leaching (a) and XRD pattern change (b). Conditions: grinding time = 250 min, Fe/LiCoO2 mass ratio = 1:1.

Influence of mechanochemical reduction time. Figure 4a shows the mechanochemical reduction time ranging from 0 to 250 min. The leaching rate of Co and Li increased higher with the prolonged mechanochemical reduction time. The extraction of Co and Li was increased from 23% to 80% and from 39% to 63%, respectively, when the reaction time was extended from 0 to 100 min, and the recovery ratio of Co and Li was stable at a high level when the reaction time was over 100 min. Furthermore, the XRD pattern intensity decreased with increasing the grinding time, and the peaks of LiCoO2 disappeared after ground for 100 min (Figure 4b), indicating that the higher leaching of Li and Co might arise from the amorphous LiCoO2 crystal.

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Figure 4 Influence of mechanochemical reduction time on Co and Li leaching (a) and XRD pattern change (b) Conditions: rotate speed = 650 rpm, Fe/LiCoO2 mass ratio = 1:1.

Characterization analysis and mechanism discussion. To elucidate the reaction mechanism in details, physicochemical changes were also investigated. As shown in Figure 3b and Figure 4b, for the samples pretreated by mechanochemical process with the addition of Fe, the XRD pattern intensity decreased and the FWHM of all peaks was also broadened with the increases of both rotation speed and grinding time. When the rotation speed and grinding time were over 550 rpm and 100 min, respectively, the peaks of LiCoO2 could disappear. In addition, the peaks of the activated samples ground without Fe are also decreased slowly (Figure S2). According to the previous studies related to mechanically activated process,30, 31 the crystal structure of the particles was destroyed and gradually transformed to an amorphous state due to the friction and impact during the grinding process. Meanwhile, the internal stress of crystal lattice would also increase with the progress of grinding. Figure

5

shows

the

morphologies

of

mechanically

activated

samples

and

mechanochemically reduced LiCoO2 powders observed by SEM. The raw materials of pure LiCoO2 with relatively larger particle sizes, whether mixed with reductive metallic iron or not, a 12


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significant reduction of the sizes could be observed after the grinding process. Furthermore, the surfaces of the particles became much rougher with the grinding time increased for both mechanically activated and mechanochemical reduction samples (Figure 5b, c, d＆e). As such, the reduction of particle size and the increase in specific surface area of particles could improve the leaching process, and a change in the crystal structure of particles also could be a reason for the significant reduction of the apparent activation energy of the leaching process. Hence, an obviously increased extraction ratio of Li from acid solution could be achieved. However, Co was hardly extracted from the activated samples by acid leaching even the crystal structure had been disordered, due to the stable chemical bonds between the Co atoms and O atoms (the states of Co in the activated sample were not changed as discussed by the following XPS analysis, Figure 6a ＆b).

Figure 5 SEM images of LiCoO2 powders: (a) raw materials, (b) activated samples (grinding time = 150 min, rotate speed = 650 rpm), (c) activated samples (grinding time = 250 min, rotate speed = 650 rpm), (d) mechanochemical reduction samples (grinding time = 100 min, rotate speed = 650 rpm, Fe/LiCoO2 mass ratio = 13



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1:1), (e) mechanochemical reduction samples with metallic iron (grinding time = 250 min, rotate speed = 650 rpm, Fe/LiCoO2 mass ratio = 1:1).

In order to gain more evidence for the enhanced leaching mechanism of Co during the mechanochemical reduction process with reductive metallic iron, XPS was performed to determine the valence states of metals in the examined samples. Calibration was conducted using C 1s peak of 284.8 eV. The photoelectron spectra of O 1s, Co 2p, and Fe 2p in LiCoO2 powders were analyzed by XPS (Figure 6). The binding energy (BE) of Co 2p3/2 in activated samples is at 779.86 eV (Figure 6a), consistent very well with that of 779.9 eV reported for LiCoO2.32, 33 Meanwhile, the BE of O 1s spectrum in activated samples (Figure 6(b)) is at 529.45 eV, which can be also in good agreement with the values of 529.0 and 529.6 eV reported for LiCoO2 by Elp et al.33 As shown in Figure 6(a), the Co 2p spectrum in the mechanochemically reduced samples showed a satellite structure. Herein, the intense satellite structures have been about 5-6 eV above the Co 2p3/2 and the Co 2p1/2 transitions, in the case of high-spin Co2+ (S = 3/2) compounds.34 However, the satellites in activated samples were very weak, and located about 10 eV above the core level lines, in the case of diamagnetic Co3+ (S = 0).35 The Co 2p3/2-Co 2pl/2 separation could increase with more unpaired electrons.36 And the separation was 15.0 eV for diamagnetic Co3+, 15.4 eV for low-spin Co2+ and 16.0 eV for high-spin Co2+ ions.35 In this work, the Co 2p spectrum of the mechanochemically reduced samples in Figure 6(a) shows satellite structure about 6 eV above the main Co 2p transition and the Co 2p3/2-Co 2p1/2 separation was found to be 15.6 eV. The Co 2p spectrum of activated samples shows satellite structure about 10 eV above the main Co 2p transition and the Co 2p3/2-Co 2p1/2 separation is found to be 15.1 eV. These results indicate that the valence state of Co was not changed after activated process without Fe, i.e. Co(III), while the 14


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oxidation state of Co was changed from Co(III) to Co(II) after mechanochemical reduction process with Fe. This might be responsible for the difficult extraction of Co from the activated sample but easy extraction from the mechanochemical reduction sample by acid leaching. The Fe 2p spectra for the mechanochemical reduction sample are shown in Fig. 6(c). The BEs of Fe 2p1/2 and Fe 2p2/3 were measured as 724 and 710.76 eV. According to the handbook of X-ray photoelectron spectroscopy,37 the peaks of Fe(III) in Fe2O3 are located at 724.3 eV for Fe 2p1/2, and 710.7 eV for Fe 2p3/2 respectively. That is to say that Fe2O3 appeared after mechanochemical reduction process with Fe. Two resolved peaks can be observed in each spectrum of the O ls in Figure 6(b). The larger binding energy peak is broader in the mechanochemical reduction samples than that on the activated samples, which is caused by the formation of Fe2O3 and the break of LiCoO2. Therefore, the change of valence state in Co was proposed for the mechanochemical reduction process (Eq.2). 3Co(III) + Fe(0) → 3Co(II) + Fe(III)

(2)

Based on these prior observations, the destroyed crystal structure, amorphous state and much rougher surfaces of LiCoO2 were the reasons that leaching efficiency of Li was improved. And the high leaching efficiency of Co was improved by the valence state change of Co in the LiCoO2 in the mechanochemical reduction process with iron powders.

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Figure 6 XPS core level spectra of Co, O, and Fe in different samples. 16


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Cobalt and Lithium Extraction from the Wasted LIBs. To verify the effectiveness of novel mechanochemical reduction process for the pretreatment of valuable metals leaching from spent LIBs in acidic solutions, the actual cathode materials disassembled from waste LIBs were also examined, and the experimental conditions were the same. The metal contents of the cathode materials are shown in Table S1. Compared with pure materials, the extractions of Li, Co, Mn and Ni were all increased obviously after 2 h leaching in a 1mol/L HNO3 solution at room temperature, which were in good agreement with the aforementioned results. It is worth mentioning that the extraction of Co, Mn and Ni was significantly higher than that of activated samples. The yields of Co increased from 20.43% to 91.25%, and the yields of Mn and Ni also increased from 33.19% and 38.67% to 100% and 99.9%, respectively, between actual material and mechanochemical reduction samples (Figure 7a). In addition, over 99% of Fe can be leached out by this mechanochemical reduction process in acid solutions. Figure7b shows the XRD patterns of different samples. The crystal structure changed dramatically, and the XRD pattern intensity was decreased and the peaks nearly disappeared in both the activated and mechanochemical reduction samples. Compared with many other studies, the leaching efficiency is relatively higher. For example, the leaching efficiency of Co is 70% under the conditions of 2 mol/L H2SO4+5% H2O2 with a leaching time of 1 h at 75 °C,38 and 90% of Co under the conditions of 1.5 mol/L DL-malic acid (C4H5O6)+2.0% H2O2 with a leaching time of 40 min at 90 °C,

14

and also 45% of Co by

bioleaching using Aspergillus niger.39 Compared with these present conditions of 1 mol/L HNO3 with leaching time of 2 h at room temperature, the aforementioned conditions in the previous 17



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studies38,14,39 need higher acid concentrations and higher temperature, which might result in more environmental risk and operational difficulties. Therefore, the results of cathode materials disassembled from waste LIBs further illustrate that the mechanochemical reduction process with Fe is an effective pretreatment approach.

Figure7 Yields of Li, Co, Mn and Ni extracted from different samples (a) and XRD pattern of the different samples; (b) Conditions: grinding time = 250 min, rotation speed = 550 rpm, Fe/LiCoO2 mass ratio = 1:1.

Conclusions An enhanced leaching for valuable metals in dilute acid solution from wasted LIBs via mechanochemical reduction process with Fe is examined. The mass ratios of Fe/LiCoO2, rotation speed and mechanochemical reduction time have positive influences on the leaching of Co, while almost have no effects on the extraction of Li. Based on the characterization analysis conducted by XRD, SEM and XPS, the mechanochemical mechanism was proposed. The reduction of particle sizes, increase of specific surface area, and changes of the crystal structure of particles by mechanical activation enhance the leaching of Li. While, for high-efficiency extraction of Co, besides for the aforementioned reasons for Li, the mechanochemical reduction by Fe to change the valence state of Co played a dominant role. Ultimately, over 77% of Li, 91% of Co, 100% of Mn 18


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and 99% of Ni can be extracted from actual wasted LIBs pretreated by this novel mechanochemical reduction process in dilute acid solutions. The present study presents a promising technology for cyclic regeneration of valuable metals from waste LIBs.

Acknowledgments We gratefully appreciate the financial supports from Natural Science Foundation of China (51678353), Shanghai Sailing Program (15YF1404300), Shanghai “Chenguang” Program (15CG60), Shanghai Natural Science Foundation (No. 15ZR1416800), Shanghai University Youth Teacher Funding Program (ZZZZEGD15011), Cultivate discipline fund of Shanghai Polytechnic University (XXKPY1601) and Eastern Scholar Professorship Grant. The authors also acknowledge the Graduate Student Funding Program of Shanghai Polytechnic University (A01GY16F030), Project supported by Shanghai Cooperative Centre for WEEE Recycling (ZF1224), Shanghai Pudong New Area of Science and Technology Development Fund (PKJ2015C07 & PKJ2015-C14), and Qingpu “Industry-University-Institute” Cooperation Development Fund (Qing 2015-9). Supporting Information Pretreatment of the waste cathode materials; Metal contents; Influence of direct leaching time; XRD patterns of activated sample. This material is available free of charge via the Internet at http://pubs.acs.org.

References (1) Etacheri, V.; Marom, R.; Ran, E.; Salitra, G.; Aurbach, D. Challenges in the Development of Advanced LiIon Batteries: A Review. Energ Environ. Sci. 2011, 4, 3243-3262. 19



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Table of Content Entry Mechanochemical Process Enhanced Cobalt and Lithium Recycling from Wasted Lithium-ion Batteries Jie Guan1, Yaguang Li1, Yaoguang Guo1,*, Ruijing Su1, Guilan Gao1, 2,*, Haixiang Song,3 Hao Yuan1, Bo Liang1, Zhanhu Guo3,*

The mechanochemical process demonstrated to enhance the acid leaching of valuable metals under ambient conditions. This process might open a new pretreat method for Li-ion batteries recycling and provide an alternative to the industries.

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Mechanochemical Process Enhanced Cobalt and Lithium Recycling

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