Nickel-rich battery recycling

Abstract

To provide nickel-rich battery recycling.SOLUTION: A method for recycling lithium from high nickel lithium batteries comprises: agitating used lithium batteries to generate a black mass of high nickel cathode materials including cathode material of at least 80% nickel; determining a quantity of a leaching acid based on a molar quantity of lithium in the black mass for achieving a molar ratio in the range of 0.4-0.70 of the leaching acid to Li in the black mass; adding the determined quantity of leaching acid to the black mass to form a leach mixture; mixing the leach mixture and heating it at 60-80°C for 1-6 hours; filtering the leach mixture with a 1-micron filter membrane for removing undissolved materials; removing dissolved nickel from the leach mixture via nanofiltration to yield a lithium sulfate solution including dissolved Li from the black mass; and concentrating the lithium sulfate via reverse osmosis and evaporation to a crystalline form.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] Related Applications This patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Patent Application No. 2022 / 0136664, entitled “NICKEL-RICH BATTERY RECYCLING,” filed September 30, 2022, the entirety of which is incorporated herein by reference. [Background technology]

[0002] background Lithium-ion (Li-ion) batteries are chemical entities suitable for secondary (rechargeable) batteries in high discharge applications such as electric vehicles (EVs) and power tools where rapid acceleration of electric motors is required. Lithium-ion batteries contain charge materials, conductive powders, and binders applied or deposited on current collectors, which are typically planar sheets of copper or aluminum. The charge materials include an anode material, typically graphite or carbon, and a cathode material, which contains a given ratio of metals such as lithium, nickel, manganese, cobalt, aluminum, iron, and phosphorus, defining the so-called "battery chemistry" of a lithium-ion battery. The preferred battery chemistry varies by supplier and application, and lithium-ion battery recycling efforts typically follow a given molar ratio of the battery chemistry for the recycled charge material product. Industry trends are moving toward more nickel-rich chemistries, often using nickel, manganese, and cobalt (NMC) in N:M:C molar ratios such as 5:3:2 (532), 6:2:2 (622), and 8:1:1 (811). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Provisional Patent Application No. 63 / 412,025 Summary of the Invention [Means for solving the problem]

[0004] overview In the battery recycling process, lithium is recovered from nickel-rich cathode material in the spent battery recycle stream. Dilute acid leaching of the high nickel content cathode material involves a mixture of sulfuric acid based on the molar amount of lithium in the cathode material. Highly selective leaching produces a lithium-rich solution with small amounts of nickel that can be removed by nanofiltration, achieving highly efficient recovery of lithium contained in the recycle stream. The amount of leaching acid based on lithium content and the amount of water based on the total black mass of the recycle stream results in highly selective, nearly pure lithium leaching when the recycle stream is derived from high nickel NMC batteries such as 811.

[0005] The configurations herein are based, in part, on the recognition that as many electric vehicles reach the end of their useful lives, a potentially large recycling stream will arise from charging materials that may generate a hazardous waste source. Unfortunately, conventional approaches to EV battery recycling tend to focus on nickel, manganese, and cobalt, which form important ratios in the battery chemistry. Lithium has often been overlooked as a profitable recycling target due to its relative abundance compared to other cathode material metals. Thus, the configurations herein substantially overcome the shortcomings of conventional EV battery recycling by recovering lithium from the cathode material by selectively leaching lithium from the black mass of granular anode and cathode materials present in the mixed recycling stream from agitated and disassembled batteries.

[0006] More specifically, the compositions herein demonstrate beneficial improvements resulting from a method of recycling Li from batteries having lithium-based charge material with a high mole ratio of nickel by combining a granular mass of charge material in a recycle stream from the battery with an amount of leaching acid based on the molar amount of lithium in the granular mass. The combined granular mass and leaching acid are heated to recover the lithium from the granular mass, resulting in a leaching selectivity of substantially all lithium with only minor impurities of residual materials such as nickel, cobalt, and manganese.

[0007] BRIEF DESCRIPTION OF THE DRAWINGS The above and other features will become apparent from the following description of specific embodiments disclosed herein, as illustrated in the accompanying drawings, in which like reference characters refer to the same parts throughout the different views, and in which the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a context diagram of a recycling environment suitable for use in the configurations herein. [Diagram 2] FIG. 2 is a flow chart of lithium recycling in the environment of FIG. 1. [Diagram 3] 1 is a graph of leaching selectivity based on lithium to sulfuric acid ratio. [Figure 4] Charts of the quantitative results of leaching in Figs. [Diagram 5] The reverse results of leaching using a less highly nickel charged material are shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Detailed Description of the Invention Below are examples of methods and techniques for recycling batteries such as nickel-rich (NMC811, or at least 80% nickel cathode material) to selectively produce lithium with small amounts of nickel and negligible cobalt and manganese. Lithium-ion batteries are used in many applications and are becoming increasingly important for electronics, electric vehicles, and energy storage systems. To meet new EV requirements, the increasing demand for lithium places a strain on recycling from natural sources (mining, separation / concentration from ocean or lake water) or from used lithium-ion batteries. The natural resources involved are limited and traditional recycling processes are very detrimental to the environment. Used (end-of-life and / or exhausted) lithium-ion batteries are a viable source of lithium and represent a higher lithium density than most natural sources. High-nickel ternary or quaternary batteries are gaining attention due to their higher energy capacity and lower raw material costs. High-nickel batteries reach the end of their life within 5-10 years and represent the majority of used lithium-ion batteries. Early stage lithium recovery methods from black mass are becoming increasingly important to preserve lithium from used batteries. It would therefore be beneficial to develop methods for early stage, highly selective lithium leaching and recovery from high nickel NMC or NCMA batteries, which will define the majority of spent EV batteries in the near future.

[0010] FIG. 1 is a context diagram of one embodiment of a recycling environment suitable for use with the configurations herein. Referring to FIG. 1, in a battery recycling environment 100, a recycling stream 101 provides granulated battery casings 110, current collectors 111, and charge material 112 as a result of agitation (e.g., crushing, grinding, pulverization) of spent batteries 105. The agitated and disassembled batteries often result in a mixed mix including black chunks representing a mixture of both cathode material (typically NMC) and anode material (graphite and carbon). Various other impurities may also appear, such as iron, aluminum, and copper, originating from the physical casing, as well as the current collectors and internal contacts. The particular configurations herein provide for lithium to be selectively leached from spent high-nickel NMC ternary and / or NMCA quaternary lithium-ion batteries using dilute sulfuric acid.

[0011] The disclosed approach is optimal when the percentage of Ni in the battery cathode metal is 80% or more. The black mass containing the cathode material is combined in a leaching mixture 120 with a solution of a leaching acid, such as sulfuric acid, and water. A containment vessel 122 receives the black mass along with the leaching acid (sulfuric acid in this embodiment). Preferably, the molar ratio of leaching acid to lithium is 0.4-0.7 (e.g., 0.45-0.7 or 0.45-0.6) and the water (volume) to black mass solids (weight) ratio is 1-5. In other words, the sulfuric acid is based on the molar amount of Li and the water is based on the weight of the black mass.

[0012] In the containment vessel 122, the heat source 124 provides a reaction temperature of 60°C to 100°C with a reaction time of 1 hour to 6 hours. The product 130 obtained from the leachate in the containment vessel 122 provides 80-99% lithium leaching, nickel leaching is less than 3-10%, and cobalt and manganese leaching rates are negligible. Nickel impurities in the leachate can be removed by nanofiltration. The lithium in the product 130 is recovered as Li2SO4 by crystallization, or converted to LiOH by adding Ca(OH)2, CaO, Mg(OH)2 or MgO, converted to Li2CO3 by adding Na2CO3, or converted to LiF by adding NaF or HF.

[0013] Figure 2 is a flow chart 200 for recycling lithium in the environment of Figure 1. With reference to Figures 1 and 2, a method for recycling lithium from Li-ion batteries includes, in step 201, identifying a Li-ion recycle stream based on high nickel (NMC811 and above) spent batteries. Selective leaching of lithium occurs most readily when the nickel concentration in the charged material / black mass is high. This is because nickel dissolves in Ni in the presence of leaching acid. 3+ From Ni 2+ In step 202, a granular mass of charge material is received in a recycle stream from a battery having a high nickel lithium-based charge material, and a leach acid is combined with the granular mass based on the molar amount of lithium in the granular mass, as shown in step 203. Sulfuric acid may be used as the leach acid, alternatively hydrochloric acid, acetic acid, nitric acid, formic acid, oxalic acid, boric acid, or other suitable organic or inorganic acids may be used based on their ability to selectively dissolve lithium without introducing excess nickel into the leach solution.

[0014] This involves calculating or otherwise determining the amount of leaching acid based on achieving a 0.45 to 0.7 molar ratio of H2SO4 to Li in the charging material, as shown in step 204. The amount of acid can be generalized to be about 2 to 1 lithium to sulfate, and therefore the amount of acid is based on the mole ratio of lithium in the cathode portion of the black mass. The construction of the battery will dictate the ratio of cathode and anode materials, which in most cases will be approximately substantially equal, and the battery chemistry will indicate the metals that combine with the lithium to define the cathode material. Recall that leaching is most selective when nickel is about 80% of the cathode material.

[0015] A heat source 124 heats the granular mass and leaching acid mixture 120 to recover lithium from the granular mass, achieving highly selective lithium leaching over a period of several hours.

[0016] The disclosed approach provides a simple, unique and cost-effective method for recycling lithium. In a typical configuration, high nickel NMC or NMCA black mass (BM) is dispersed in a known amount of dilute sulfuric acid solution (H2SO4 / cathode molar ratio = 0.45-0.70, H2O(v) / BM(w) ratio = 1-5). The mixture is then stirred at 60-100°C for 1-6 hours. After reaction, the mixture is filtered through a 1 micron filter membrane. Nickel impurities are then removed by nanofiltration (NF). The cleaned permeate from nanofiltration is a lithium sulfate solution. This solution is further concentrated by reverse osmosis (RO) filtration, followed by crystallization of lithium sulfate from the concentrate by further evaporation. The lithium in the RO concentrate can be recovered as Li2CO3 precipitate by addition of sodium carbonate or as lithium halide by precipitation with sodium fluoride or hydrofluoric acid. The lithium sulfate in the RO concentrate can also be converted to lithium hydroxide by adding calcium, magnesium hydroxide, or magnesium oxide, removing the by-product calcium or magnesium sulfate precipitate by ultrafiltration, and then crystallizing LiOH from the filtrate.

[0017] Figure 3 is a graph 300 of leaching selectivity based on the ratio of lithium to sulfuric acid. In Figure 3, the percentage leached of Li (301) is shown along with the percentage leached of Ni (303), which can be subsequently removed to produce substantially pure lithium sulfate, at various ratios of sulfuric acid to Li on the horizontal axis 305. The results disclosed show high lithium leaching and selectivity. There is a negligible percentage of Ni leached with Li, preferably 10% or less. The amount of Co and Mn leached is negligible.

[0018] Figure 4 shows a chart 400 of the quantitative results of the leaching in Figures 1-3. Referring to Figure 4, three leaching tests are shown that vary the molar ratio of leaching acid to lithium, demonstrating substantial recovery of Li with minimal leaching of Ni.

[0019] FIG. 5 shows the reverse result 500 of leaching using a less high nickel charge material. As shown above, the high nickel content in the cathode material, at least 80% Ni as in the case of NMC-811, contributes to the highly selective nature of the leaching recovery of virtually all of the lithium. FIG. 5 shows the difference with a lower nickel charge material such as NMC-622. Lithium (501) still accounts for the majority of the leached metals, but the metals of the other cathode materials appear in more undesirable amounts. For example, Ni content (503) has the second highest leaching yield, followed by Co (505) and Mn (507).

[0020] In a particular configuration, the disclosed method for recycling lithium from high nickel lithium batteries includes agitating a spent lithium battery recycle stream to produce a black mass of high nickel cathode material containing at least 80% nickel cathode material, and determining an amount of sulfuric acid based on the molar amount of lithium in the black mass to achieve a molar ratio of H2SO4-Li ranging between 0.4-0.70, or generally a molar ratio of lithium to acid of about 2-1, or more specifically a molar ratio of 2.0 moles of Li to 1.0-1.2 moles of sulfuric acid. In this approach, the determined amount of sulfuric acid and the black mass are combined to form a leach mixture, and the leach mixture is then mixed and heated at 60-80°C for 1-6 hours. The leach mixture is filtered through a 1 micron filter membrane to remove undissolved material from the black mass, and dissolved nickel is removed from the leach mixture by nanofiltration to obtain a lithium sulfate solution containing dissolved Li from the black mass. The recycled charge material precursor can be recovered by concentrating the lithium sulfate into a crystalline form by reverse osmosis and evaporation.

[0021] Although the systems and methods defined herein have been particularly shown and described with reference to embodiments thereof, those skilled in the art will understand that various changes in form and details can be made therein without departing from the scope of the invention as encompassed by the appended claims. [Explanation of symbols]

[0022] 100 Battery Recycling Environment 101 Recycling process 105 Batteries 110 Battery casing 111 Current collector 112 Charging materials 120 Leaching mixture 120 mixture 122 Containment Vessel 124 Heat source 130 Product 200 Flowchart 201 Process 202 Process 203 Process 204 Process 300 Graphs Percentage of leaching of 301Li Percentage of 303 Ni leaching 305 horizontal axis 400 Charts 500 results 501 Lithium 503 Ni 505 Co 507 Mn

Claims

1. 1. A method for recycling lithium from batteries, comprising: combining a quantity of leaching acid from a battery recycle stream with a quantity of granular mass of charge material, said quantity of leaching acid being based on the molar amount of lithium in said granular mass; heating the combined granular mass and leach acid; recovering lithium from said granular mass; A method comprising:

2. 10. The method of claim 1, wherein the granular mass of charge material comprises a cathode material having at least 80 mole percent nickel.

3. 2. The method of claim 1, wherein the amount of leaching acid is based on achieving a molar ratio of 0.4 to 0.7 of leaching acid to Li in the granular mass of charged material.

4. 10. The method of claim 1, wherein the granular mass of the charge material is received from a recycling stream of batteries having lithium-based charge material.

5. 5. The method of claim 4, wherein the recycle stream is based on cells having a cathode material of at least 80% nickel.

6. 2. The method of claim 1, wherein the molar ratio of the leaching acid to Li in the granular mass is from 0.045 to 0.

6.

7. 10. The method of claim 1, wherein the lithium recovered from the granular mass contains less than 10% nickel.

8. 10. The method of claim 1, wherein the lithium recovered from the granular mass contains between 3% and 10% nickel.

9. 10. The method of claim 1, wherein the leaching agent comprises an acid selected from the group consisting of sulfuric acid, hydrochloric acid, acetic acid, nitric acid, formic acid, oxalic acid, and boric acid.

10. 1. A method for recycling lithium from a high nickel lithium battery, comprising: agitating a recycled stream of spent lithium batteries to produce a black mass of high-nickel cathode material comprising at least 80% nickel cathode material; determining the amount of leaching acid based on the molar amount of lithium in the black mass to achieve a molar ratio of leaching acid to Li in the black mass in the range of 0.4 to 0.70; adding said determined amount of leaching acid to said black mass to form a leaching mixture; mixing and heating the leaching mixture at 60-80°C for 1-6 hours; filtering the leaching mixture through a 1 micron filter membrane to remove undissolved materials; removing dissolved nickel from the leach mixture by nanofiltration to produce a lithium sulfate solution containing dissolved Li from the black mass; concentrating the lithium sulfate into crystalline form by reverse osmosis and evaporation; A method comprising:

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