A method for lithium recycling from end-of-life batteries

Abstract

We provide a method for recycling lithium from lithium iron phosphate batteries in an economical, environmentally efficient, and high-efficiency manner. A method for recycling lithium from a lithium iron phosphate battery, comprising the following steps: (a) a step of obtaining a Li+ aqueous mother liquor by adding iron trichloride (FeCl3) to a powder containing lithium iron phosphate (LiFePO4) obtained from a lithium iron phosphate battery; (b) a step of filtering the above Li+ aqueous solution mother liquor to separate solid residues and obtaining a Li+ leachate; (c) a step of adding a base to the above Li+ leachate to precipitate iron hydroxide (Fe(OH)3); (d) a step of recovering a lithium chloride (LiCl) solution; and (e) A step of recovering iron trichloride (FeCl3) from the iron hydroxide (Fe(OH)3) in step (c) and reusing it in step (a).

Description

Technology Field

[0001] The present invention relates to a method for recycling lithium from waste batteries. Background Technology

[0002] As the lithium-ion battery market expands rapidly, the secondary battery industry faces a high dependence on imports for key raw materials, such as lithium. Consequently, it is essential to recover important resources, including lithium, from high-lithium sources like discarded lithium-ion batteries and to recycle them to produce new cathode materials.

[0003] However, compared to batteries that use raw materials more expensive than lithium, such as nickel, cobalt, and manganese, the recycling of lithium-ion batteries offers few economic advantages. Therefore, in terms of economic feasibility, the recycling of lithium-ion batteries requires low-cost leaching agents and a simplified recycling process.

[0004] In addition, recently, issues related to landfill restoration costs and environmental pollution resulting from the disposal of lithium-ion batteries have also arisen.

[0005] Accordingly, in Non-patent Literature 1 and Patent Literature 1, it is proposed to produce an efficient new cathode material by recovering key materials from high-lithium-content raw materials, such as discarded lithium-ion batteries, and reusing them to meet the demand for lithium that relies on imports.

[0006] Meanwhile, in the case of lithium iron phosphate (LFP) batteries, there is a problem with poor economic feasibility of recycling due to the low economic value of iron (Fe) and phosphorus (P). Accordingly, the economic recycling of spent lithium iron phosphate batteries is emerging as an important research area. Non-patent literatures 2 and 3 propose a direct regeneration method as a method for recycling spent lithium iron phosphate batteries. However, this direct regeneration method is limited to high-purity LFP batteries, which limits its use and practical application in large-scale manufacturing processes.

[0007] Furthermore, in Non-Patent Literature 4, conventional leaching processes using organic acids such as sulfuric acid (H2SO4) or oxalic acid (H2C2O4) entail specific difficulties in the method of leaching trivalent iron salts. Li from the leachate + and Fe 2+ / Fe 3+ Additional processes such as solvent extraction are required to separate them, which entails a complex process. Furthermore, the use of sulfuric acid is required, and the resulting Fe2(SO4)3 and Fe2(C2O4)3 are low-value-added products. These processes increase the amount of chemicals used and wastewater generated, thereby hindering the economic and environmental efficiency of the iron salt leaching method. Therefore, to ensure the economical recycling of waste batteries, it is essential to develop a low-cost recycling method that does not compromise environmental efficiency. Prior art literature

[0008] Korean Published Patent Application 10-2021-0010523 (2021.01.26)

[0009] T. Nshizirungu et al. Journal of Hazardous Materials 393 (2020) 122367H. Pu et al. Journal of Energy Storage 111 (2025) 115421X. Li et al. Nano Energy 140 (2025) 111014Z. Zhao et al. Journal of Power Sources 628 (2025) 235939 The problem to be solved

[0010] The present invention aims to solve the above-mentioned problems by providing a method for recovering lithium, specifically lithium chloride (LiCl), which is a recyclable precursor, from spent lithium iron phosphate (LFP) batteries.

[0011] Specifically, the purpose is to provide an economical, environmentally efficient, and practical method for recovering lithium chloride (LiCl), a recyclable precursor from waste LFP batteries, by using low-cost iron trichloride (FeCl3) as an oxidizing agent and / or leaching agent, and using ammonium hydroxide (NH4(OH)) to remove impurities, thereby simplifying the process, reducing the generation of polluting by-products, and minimizing wastewater generation. means of solving the problem

[0012] The inventors added iron trichloride (FeCl3) to lithium iron phosphate (LiFePO4) obtained from an LFP battery to obtain solid FePO4 / C and Li + It was discovered that the above objective could be achieved by obtaining a mixture of aqueous mother liquor, precipitating and removing iron hydroxide (Fe(OH)3) from it, and recovering a lithium chloride (LiCl) solution, and thus the present invention was completed.

[0013] The present invention includes the following aspects.

[0014] <1> A method for recycling lithium from a lithium iron phosphate battery, comprising the following steps:

[0015] (a) Iron trichloride (FeCl3) is added to a cathode powder containing lithium iron phosphate (LiFePO4) obtained from a lithium iron phosphate battery to Li + Step of obtaining the aqueous mother liquor;

[0016] (b) The above Li + Filter the aqueous mother liquor to separate the solid residue, and Li + A solution rich in (hereinafter, Li + Step of obtaining the leachate;

[0017] (c) The above Li + A step of adding a base to the leachate to precipitate iron hydroxide (Fe(OH)3);

[0018] (d) a step of recovering a lithium chloride (LiCl) solution; and

[0019] (e) A step of recovering iron trichloride (FeCl3) from the iron hydroxide (Fe(OH)3) in step (c) and reusing it in step (a).

[0020] A method for recycling lithium from a lithium iron phosphate battery described in <1>, wherein the iron trichloride in step (a) of <2> is added in the form of an aqueous solution, and the concentration of iron trichloride in the aqueous solution is 0.15 to 1.5 M.

[0021] A method for recycling lithium from a lithium iron phosphate battery as described in <1>, wherein the iron trichloride in step (a) of <3> functions as an oxidizing agent and a leaching agent.

[0022] <4> Step (a) comprises heating at a temperature of 50 to 95°C for 0.5 to 3 hours, a method for recycling lithium from a lithium iron phosphate battery as described in <1>.

[0023] A method for recycling lithium from a lithium iron phosphate battery as described in <1>, wherein the solid residue in step (b) of <5> comprises iron phosphate (FePO4) and graphite.

[0024] The method for recycling lithium from a lithium iron phosphate battery described in <1>, wherein the base in step (c) of <6> is ammonium hydroxide (NH4OH).

[0025] <7> The above ammonium hydroxide is Li + For the leachate, 1:2 to 1:3 [ammonium hydroxide : Li + A method for recycling lithium from a lithium iron phosphate battery described in <6>, added in a volume ratio of [leaching solution].

[0026] The above base in step <8> (c) is Li + A method for recycling lithium from a lithium iron phosphate battery described in <1>, wherein the leaching solution is added to reach a pH of 7 to 9.5.

[0027] Step <9> (c) is, Li + A method for recycling lithium from a lithium iron phosphate battery as described in <1>, comprising adding hydrogen peroxide (H2O2) when the pH of the leaching solution reaches 8.

[0028] <10> The amount of hydrogen peroxide added above is the Li obtained in step (b) above. + A method for recycling lithium from a lithium iron phosphate battery described in <9>, wherein 5 to 10 ml is used for every 100 ml of leachate.

[0029] Step 〈11〉 (d) is,

[0030] Li + A step of obtaining a first solution by removing iron hydroxide precipitates from the leachate, and

[0031] A method for recycling lithium from a lithium iron phosphate battery as described in <1>, comprising the step of washing the removed iron hydroxide precipitate with deionized water to obtain a second solution.

[0032] 〈12〉Li + A method for recycling lithium from a lithium iron phosphate battery described in <11>, wherein a filter paper having a pore size of 5 μm or less is used in the step of removing iron hydroxide precipitates from a leachate to obtain a first solution.

[0033] The lithium chloride solution recovered in step (d) of <13> comprises the first solution and the second solution, a method for recycling lithium from a lithium iron phosphate battery as described in <11>.

[0034] <14> Step (e) comprises reacting iron hydroxide with an aqueous solution of 3 M hydrochloric acid (HCl), a method for recycling lithium from a lithium iron phosphate battery as described in <1>. Effects of the invention

[0035] According to the present invention, lithium can be recovered and recycled with high efficiency using inexpensive reagents. In addition, environmentally efficient recycling of lithium is possible by using low-toxicity reagents.

[0036] According to the present invention, the time required for the lithium recycling process can be reduced. Brief explanation of the drawing

[0037] FIG. 1 is a flowchart of the method of the present invention for recovering lithium chloride (LiCl) from an LFP battery. Specific details for implementing the invention

[0038] The invention described herein provides a method for recycling lithium from lithium iron phosphate (LFP) batteries. Specifically, it provides a method for recovering lithium chloride (LiCl) with high efficiency from end-of-life waste LFP batteries.

[0039] FIG. 1 illustrates the method of the present invention for recovering lithium chloride (LiCl) from an LFP battery in steps.

[0040] The present invention relates to (a) adding iron trichloride (FeCl3) to a cathode powder containing lithium iron phosphate (LiFePO4) obtained from a lithium iron phosphate battery, thereby Li + It includes the step of obtaining an aqueous solution mother liquid.

[0041] The above step begins by discharging the spent LFP battery and then decomposing it to obtain cathode powder containing lithium iron phosphate. Discharging the LFP battery is a safety measure to prevent fire accidents. The obtained cathode powder contains lithium iron phosphate, and preferably contains lithium iron phosphate and graphite.

[0042] Next, an oxidizing agent is added to the obtained cathode powder. When an oxidizing agent is added to the cathode powder containing lithium iron phosphate, Li + Li rich in + An aqueous mother liquor can be obtained.

[0043] As an oxidizing agent added to the cathode powder, iron trichloride (FeCl3) is preferred in terms of low cost and environmental efficiency. Iron trichloride can function not only as an oxidizing agent but also as a leaching agent.

[0044] It is preferable that iron trichloride be added to the LiFePO4 cathode powder in the form of an aqueous solution. The concentration of iron trichloride in the aqueous solution may be 0.15 to 1.5 M, and is preferably 0.75 to 1 M. If the concentration of iron trichloride is low, Li + The leaching yield of may decrease. Meanwhile, if the concentration of iron trichloride is high, Li + The amount of iron-containing impurities in the leachate increases, and therefore, the amount of base added to remove the iron-containing impurities must be increased.

[0045] In one embodiment of the present invention, iron trichloride is dissolved in deionized water at 20 to 25 °C. The iron trichloride dissolved in deionized water is Fe 3+ and Cl -It can be completely dissociated to create an acidic solvent environment.

[0046] The reaction of adding iron trichloride to a cathode powder containing lithium iron phosphate is initiated by heating a mixture of the cathode powder and an aqueous solution of iron trichloride. The reaction of adding iron trichloride preferably includes heating and stirring at a temperature of 50 to 95°C using a hot plate for 0.5 to 3 hours.

[0047] The present invention comprises: (b) the above Li + Filter the aqueous mother liquor to separate the solid residue, and Li + It includes the step of obtaining the leachate.

[0048] Li obtained through the above step (a) + The aqueous mother liquor contains solid residues. Therefore, a purification process is required to remove the solid residues. Li + The solid residue contained in the aqueous mother liquor preferably includes iron phosphate (FePO4) and graphite.

[0049] The above solid residue is Li + The aqueous mother liquor is separated by filtration. Li + Filter paper can be used for filtration of the aqueous solution. After filtration, Li + By removing solid residues separated from the aqueous mother liquor, Li + A leachate is obtained.

[0050] The present invention includes the step of (c) adding a base to the Li+ leaching solution to precipitate iron hydroxide (Fe(OH)3).

[0051] Li obtained through step (b) above + The leaching solution contains a significant amount of lithium, but also includes residual impurities. Therefore, a purification process is required to remove the residual impurities. Li + The residual impurities present in the leachate are preferably Fe 2+and Fe 3+ Includes

[0052] To remove residual impurities, Li + A base may be added to the leachate. The base may be a weak base or a strong base. The base may be ammonium hydroxide (NH4OH), sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2), as well as Fe 3+ Organic amines that can form a complex with, for example, triethanolamine (TEA), ethylenediamine, and glycine, may be, but are not limited to, these.

[0053] Li + When adding a base to the leachate, pH control can be very important. By adding a base, Li + The pH of the leachate may increase. In this case, the base is Li + It is added so that the pH of the leachate reaches 7 to 9.5, preferably 8 to 9.5.

[0054] Preferably, ammonium hydroxide (NH4OH) may be used. When using ammonium hydroxide, Li + It is possible to remove impurities capable of forming metal hydroxides, such as iron and aluminum, from the leaching solution, and at the same time, Li + The pH of the leaching solution can be increased. This increases the recovery efficiency of lithium chloride. In addition, when ammonium hydroxide is used as a base, there is an advantage that removing ammonium chloride (NH4Cl) coexisting in the lithium chloride solution is relatively easier than removing other chlorides (e.g., sodium chloride). Furthermore, there is an advantage that the added value of the ammonium chloride produced in this separation process is greater than that of other chlorides (e.g., sodium chloride).

[0055] Ammonium hydroxide is Li + For the leachate, 1:2 to 1:3 [ammonium hydroxide : Li+ It is preferable to add it in a volume ratio of the [leaching solution].

[0056] By adding a base, Li + Fe contained in the leachate 3+ It can precipitate as iron hydroxide (Fe(OH)3). However, Li + Fe contained in the leachate 2+ is not precipitated, and Li + It still exists in a dissolved state in the leachate. Li + Fe contained in the leachate 2+ To remove, Fe 2+ to Fe 3+ It is necessary to oxidize it to Li. + By adding hydrogen peroxide (H2O2) to the leaching solution, Fe 2+ Ga Fe 3+ It is oxidized to. At this time, hydrogen peroxide is Li + It is preferable to add it when the pH of the leachate reaches 8. The amount of hydrogen peroxide added is the Li obtained in step (b) above. + For every 100 ml of leachate, 5 to 10 ml is preferred. Oxidized Fe 3+ It can be precipitated as iron hydroxide.

[0057] As described above, the iron hydroxide precipitated by the addition of a base and hydrogen peroxide is Li + The leachate can be separated by filtration. Li + For filtration of the leachate, filter paper may be used, and preferably, filter paper with a pore size of 5 μm or less may be used. After filtration, Li + Remove iron hydroxide separated from the leachate. Li from which iron hydroxide has been removed + The leachate is prepared to undergo a concentration process to recover the lithium chloride (LiCl) solution.

[0058] The present invention includes (d) a step of recovering a lithium chloride (LiCl) solution.

[0059] The recovered lithium chloride solution includes the following first solution, and preferably includes the following first solution and second solution.

[0060] The first solution is Li in step (c). + It is a solution obtained by removing precipitated iron hydroxide from the leachate.

[0061] Since lithium remains in the iron hydroxide removed during the process of obtaining the first solution, the remaining lithium can be recovered from it. The second solution is Li + It is a solution obtained by washing the iron hydroxide removed from the leachate with deionized water.

[0062] The present invention includes the step of (e) recovering iron trichloride (FeCl3) from the iron hydroxide (Fe(OH)3) precipitated in step (c) and reusing it in step (a).

[0063] The iron hydroxide removed after precipitation in step (c) above can be reused without being discarded, preferably after being washed with deionized water in step (d) above.

[0064] To reuse iron hydroxide, iron trichloride is recovered by reacting iron hydroxide with a strong acid. It is preferable to dissolve iron hydroxide in an aqueous hydrochloric acid (HCl) solution, and it is even more preferable to dissolve iron hydroxide in a 3 M aqueous hydrochloric acid solution. It is preferable to react the iron hydroxide with the aqueous hydrochloric acid solution at 80 to 90°C for 15 to 30 minutes. It is preferable that the molar ratio of iron hydroxide to hydrochloric acid in the aqueous hydrochloric acid solution is 5:1 to 1:5.

[0065] Iron trichloride recovered from iron hydroxide is reused in step (a) as an oxidizing agent and / or leaching agent.

[0066] The present invention is not limited to a method for recycling lithium from waste LFP batteries, but also provides a method for recycling iron phosphate (FePO4) and graphite.

[0067] In a method for recycling lithium from waste LFP batteries, the Li of step (a) + The solid residue removed from the aqueous mother liquor may include iron phosphate (FePO4) and graphite.

[0068] To separate iron phosphate and graphite from the above solid residue, an acid can be added to the solid residue to obtain an iron phosphate leaching solution. A strong inorganic acid is preferred, and hydrochloric acid is more preferred. When using hydrochloric acid, a 2 to 5 M aqueous hydrochloric acid solution is preferred.

[0069] The reaction for adding acid preferably includes heating at a temperature of 50 to 95°C for 0.5 to 3 hours.

[0070] Graphite is recovered from the obtained iron phosphate leachate through filtration. The recovered graphite can be recycled.

[0071] The iron phosphate leachate remaining after graphite recovery is dried at room temperature and recovered as iron phosphate in powder form. The recovered iron phosphate can be recycled.

[0072] Examples

[0073] The present invention will be explained in more detail below by way of examples, but the present invention is not limited by these examples.

[0074] (Composition of LiFePO4 powder)

[0075] Table 1 shows the results of three repeated analyses of cathode powder containing LiFePO4 obtained from waste LFP batteries using ICP-OES.

[0076] Content (wt%) Li Fe P Mn Co Al Ni Cu Zn Na Analysis 1 4.91 34.29 19.27 0.01 0.00 0.05 0.01 0.01 0.02 2.60 Analysis 2 4.48 33.35 18.37 0.01 0.00 0.06 0.00 0.00 0.02 0.51 Analysis 3 4.51 32.97 19.19 0.01 0.00 0.01 0.01 0.01 0.00 0.42 average 4.63 33.53 18.94 0.01 0.00 0.04 0.00 0.00 0.00 1.27

[0077] (Preparation of FeCl3 aqueous solution)

[0078] 16.2 g of FeCl3 was dissolved in deionized water at room temperature to prepare 0.75 M, 0.85 M, 0.95 M, and 1 M aqueous solutions of FeCl3, respectively.

[0079] <Test Example 1. Test of Leaching Efficiency According to Concentration of FeCl3 Aqueous Solution>

[0080] (Example 1-1)

[0081] In a reactor, 10 g of LiFePO4 obtained from spent LFP batteries and 100 ml of a 0.75 M FeCl3 aqueous solution were mixed, and heating and stirring were performed at 95 ℃ for 2.5 hours to Li + The aqueous mother liquor was obtained. Li + The aqueous mother liquor is filtered through a filter paper with a pore size of 5 μm to remove solid residues, and Li + A leachate was obtained. The obtained Li + The content of Li, Fe, and P in the leachate is shown in Table 2.

[0082] (Examples 1-2 to 1-4)

[0083] In Example 1-1, Li obtained by varying only the concentration of the FeCl3 aqueous solution + The content of Li, Fe, and P in the leachate is shown in Table 2.

[0084] Examples FeCl 3 Aqueous solution concentration (M) Li + Content (%) in leachate Li Fe P 1-1 0.75 <94 0 <0.01 1-2 0.85 <95 0 <0.01 1-3 0.95 95 0 <0.01 1-4 1 >98 0 <0.01

[0085] <Test Example 2. Li Leaching Efficiency Test>

[0086] A 1 M aqueous FeCl3 solution was prepared by dissolving 16.2 g of FeCl3 in 100 ml of distilled water. In a reactor, 10 g of LiFePO4 obtained from spent LFP batteries and 100 ml of the 1 M aqueous FeCl3 solution were mixed, and heating and stirring were carried out at 95 ℃ for 2.5 hours to Li + The aqueous mother liquor was obtained. Li + The aqueous mother liquor is filtered through a filter paper with a pore size of 5 μm to remove solid residues, and Li + A leachate was obtained. The obtained Li + The content of Li, Fe, and P in the leachate is shown in Table 3.

[0087] In Table 3 below, (a) is the Li / Fe / P content in LiFePO4 obtained from spent LFP batteries, and (b) is Li + (c) represents the Li / Fe / P content in the leaching solution, and (c) represents the Li / Fe / P content in the solid residue (FePO4 / C).

[0088] Content (wt%) Leaching efficiency (%) (a) (b) (c) Li 4.63 4.55 0.08 98.27 Fe 33.53 34.2 35.70 N / A P 18.94 0.53 18.00 N / A

[0089] <Test Example 3. Li Recovery Rate Test>

[0090] 50 ml of NH4OH is added to 100 ml of the leachate obtained in Test Example 2. When the pH of the solution reaches 8, 25 ml of H2O is added. The Li / Fe / P content and Li recovery rate of the LiCl solution obtained by removing the precipitate are shown in Table 4.

[0091] Content (wt%) Li recovery rate (%) Before removing sediment After removing sediment Li 4.55 4.45 97.80 Fe 34.2 0.04 N / A P 0.53 0.01 N / A

[0092] <Comparative Example>

[0093] LiFePO4 obtained from spent LFP batteries was subjected to a leaching reaction in the same manner as in Example 1-1, under the combination of oxidation reagent and precipitation reagent and temperature conditions shown in Table 4. The Li leaching efficiency, Li recovery efficiency, and final Li yield are shown in Table 5.

[0094] Combination of oxidizing agent / precipitating agent T (℃) Li leaching efficiency (%) Li recovery efficiency (%) Li final yield (%) Example 1-1 FeCl3 / NH4OH <95 >98 97.80 96.12 Comparative Example 1 FeCl3 / Spray Pyrolysis <500 >99 >96 N / A Comparative Example 2 Na2S2O8 / NaOH or KOH <100 >99 N / A 32 Comparative Example 3 H2SO4 / H2O2+NaOH <50 >99 N / A 57 Comparative Example 4 HCOOH / H2O2+NaOH <50 >73 N / A 37 Comparative Example 5 CH3COOH / H2O2+NaOH <50 >99 N / A 68 Comparative Example 6 H2SO4 / NaOH <110 >96 87.5 N / A

[0095] Comparative Example 1 showed excellent lithium recovery efficiency, but since lithium recovery was performed at 500°C, it is disadvantageous in terms of energy consumption. In Comparative Examples 2, 3, 5, and 6, a significant amount of lithium was leached, but the final lithium yield was not sufficiently high, so it is not suitable for the recycling method of LFP batteries. In Comparative Examples 3 and 6, a significant amount of lithium was leached, but harmful inorganic acids such as sulfuric acid are not suitable for the environmentally friendly and sustainable recycling method of LFP batteries.

Claims

Claim 1 A method for recycling lithium from a lithium iron phosphate battery comprising the following steps: (a) adding iron trichloride (FeCl3) to a cathode powder containing lithium iron phosphate (LiFePO4) obtained from a lithium iron phosphate battery, thereby Li + Step of obtaining an aqueous mother liquor; (b) the Li + Filter the aqueous mother liquor to separate the solid residue, and Li + Step of obtaining a leachate; (c) the above Li + Ammonium hydroxide (NH4OH) in the leachate, Li + A step of adding so that the pH of the leachate reaches 7 to 9.5 and adding hydrogen peroxide (H2O2) to precipitate iron hydroxide (Fe(OH)3); (d) a step of recovering a lithium chloride (LiCl) solution; and (e) a step of recovering iron trichloride (FeCl3) from the iron hydroxide (Fe(OH)3) in step (c) and reusing it in step (a). Claim 2 A method for recycling lithium from a lithium iron phosphate battery according to claim 1, wherein the iron trichloride in step (a) is added in the form of an aqueous solution, and the concentration of iron trichloride in the aqueous solution is 0.15 to 1.5 M. Claim 3 A method for recycling lithium from a lithium iron phosphate battery, wherein, in claim 1, the iron trichloride in step (a) functions as an oxidizing agent and a leaching agent. Claim 4 A method for recycling lithium from a lithium iron phosphate battery, wherein, in claim 1, step (a) comprises heating at a temperature of 50 to 95°C for 0.5 to 3 hours. Claim 5 A method for recycling lithium from a lithium iron phosphate battery according to claim 1, wherein the solid residue in step (b) comprises iron phosphate (FePO4) and graphite. Claim 6 In claim 1, the ammonium hydroxide is Li + For the leachate, 1:2 to 1:3 [ammonium hydroxide : Li + A method for recycling lithium from a lithium iron phosphate battery, added in a volume ratio of [leaching solution]. Claim 7 In claim 1, in step (c), hydrogen peroxide (H2O2) is Li + A method for recycling lithium from a lithium iron phosphate battery, adding when the pH of the leachate reaches 8. Claim 8 In claim 7, the amount of hydrogen peroxide added is the Li obtained in step (b). + A method for recycling lithium from a lithium iron phosphate battery, wherein 5 to 10 ml is used for every 100 ml of leachate. Claim 9 In claim 1, step (d) is Li + A method for recycling lithium from a lithium iron phosphate battery, comprising the steps of removing an iron hydroxide precipitate from a leachate to obtain a first solution, and washing the removed iron hydroxide precipitate with deionized water to obtain a second solution. Claim 10 In Article 9, Li + A method for recycling lithium from a lithium iron phosphate battery, wherein a filter paper with a pore size of 5 μm or less is used in the step of removing iron hydroxide precipitates from a leachate to obtain a first solution. Claim 11 A method for recycling lithium from a lithium iron phosphate battery, wherein the lithium chloride solution recovered in step (d) comprises the first solution and the second solution. Claim 12 A method for recycling lithium from a lithium iron phosphate battery, wherein, in claim 1, step (e) comprises reacting iron hydroxide with an aqueous solution of 3 M hydrochloric acid (HCl). Claim 13 delete Claim 14 delete

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