Method for manufacturing battery material

Abstract

To provide a method for manufacturing a battery material which recovers valuable metal more efficiently.SOLUTION: The method for manufacturing a battery material disclosed herein includes: a preparation step of preparing a recovery target including at least one of Ni and Co; an acid exudation step of immersing the recovery target into an acid solution and obtaining an acid exudation solution; a neutralization-precipitation step of mixing the acid exudation solution and the neutralizer with each other and obtaining a precipitation; a solid-liquid separation step of separating the precipitation into a solid material and liquid; and an ammonia exudation step of immersing the separated precipitation in the ammonia solution including ammonium ions and obtaining an ammonia exudation solution including at least one of Ni and Co.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed herein relates to a method for producing battery materials. [Background technology]

[0002] Lithium ion secondary batteries are widely used in various fields. Various materials including valuable metals such as Ni and Co are used in these lithium ion secondary batteries. For example, lithium transition metal composite oxides such as lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel cobalt composite oxide, and lithium nickel cobalt manganese composite oxide are used as the positive electrode active material. Aluminum and the like are used as the positive electrode core.

[0003] In recent years, development of recovery technologies has been promoted for recovering valuable metals from used batteries and process scraps and reusing them as battery materials. For example, Patent Document 1 discloses an example of a recovery technology for positive electrode plates. In the recovery method described in Patent Document 1, the recovery object (lithium ion battery scrap) is leached with acid, and the leaching solution obtained by the leaching is neutralized to remove at least a portion of the aluminum ions from the leaching solution to obtain a neutralized solution, and the remaining aluminum ions are extracted from the neutralized solution by performing solvent extraction on the neutralized solution. It is disclosed that cobalt (Co) and / or nickel (Ni) can be recovered from the extraction residue from which aluminum has been removed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-164971 A Summary of the Invention [Problem to be solved by the invention]

[0005] As disclosed in the above-mentioned Patent Document 1, in the conventional positive electrode plate recovery technology, at least a portion of the aluminum ions (aluminum) is precipitated and removed by neutralizing the acid leachate containing the material to be recovered. However, a portion of the precipitate may contain valuable metals (Ni and / or Co). Therefore, in the conventional positive electrode plate recovery technology, there is a risk that the valuable metals are removed from the material to be recovered, and the valuable metals cannot be sufficiently recovered.

[0006] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a method for producing a battery material with an improved recovery rate of valuable metals. [Means for solving the problem]

[0007] In order to solve the above problems, a method for producing a battery material (hereinafter, also simply referred to as a "production method") having the following configuration is provided.

[0008] The manufacturing method of a battery material disclosed herein includes a preparation step of preparing a recovery target containing at least one of Ni and Co, an acid leaching step of immersing the recovery target in an acid solution to obtain an acid leaching solution, a neutralization precipitation step of mixing the acid leaching solution with a neutralizing agent to obtain a precipitate, a solid-liquid separation step of separating the precipitate into solid and liquid, and an ammonia leaching step of immersing the separated precipitate in an ammonia solution containing ammonium ions to obtain an ammonia leaching solution containing at least one of the Ni and Co.

[0009] In the manufacturing method having the above configuration, the precipitate obtained in the neutralization precipitation step is subjected to ammonia leaching, whereby Ni and / or Co in the precipitate can be separated and dissolved in the ammonia solution, thereby improving the recovery rate of valuable metals from the target. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view that illustrates a schematic internal structure of a lithium-ion secondary battery. [Diagram 2]FIG. 2 is a perspective view that typically shows an electrode assembly of the lithium ion secondary battery shown in FIG. [Diagram 3] FIG. 3 is a flow chart illustrating a method for producing a battery material according to one embodiment. [Figure 4] FIG. 4 is a flow chart illustrating in detail the solvent extraction step in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the technology disclosed herein will be described with reference to the drawings. Matters other than those specifically mentioned in this specification and necessary for implementing the technology disclosed herein can be understood as design matters for a person skilled in the art based on the prior art in the relevant field. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in the relevant field. In addition, the expression "A to B" indicating a range in this specification includes the meaning of "A or more and B or less," as well as "preferably greater than A" and "preferably smaller than B."

[0012] 1. Items to be recalled The method for producing a battery material according to the present embodiment produces a battery material (typically, a material for a positive electrode active material of a lithium ion secondary battery, a precursor of the positive electrode active material, or a positive electrode active material) by recovering valuable metals such as Ni and Co from a predetermined recovery target. An example of the recovery target here is a used lithium ion secondary battery. Hereinafter, this lithium ion secondary battery will be specifically described. FIG. 1 is a vertical cross-sectional view that typically shows the internal structure of a lithium ion secondary battery. FIG. 2 is a perspective view that typically shows an electrode body of the lithium ion secondary battery shown in FIG. 1.

[0013] As shown in FIG. 1, the lithium ion secondary battery 1 includes a case 10, an electrode assembly 20, and an electrolyte (not shown).

[0014] (1) Case The case 10 is a box-shaped container. An electrode body 20 and an electrolyte are housed inside the case 10. For example, a metal material (such as aluminum (Al)) having a certain strength is used for the case 10. A positive electrode terminal 12 and a negative electrode terminal 14 are attached to the case 10. The positive electrode terminal 12 and the negative electrode terminal 14 are connected to the electrode body 20 inside the case 10. Specifically, the positive electrode terminal 12 is connected to a positive electrode plate 30 (see FIG. 2) of the electrode body 20. The positive electrode terminal 12 is made of aluminum (Al) or the like. On the other hand, the negative electrode terminal 14 is connected to a negative electrode plate 40 of the electrode body 20. The negative electrode terminal 14 is made of copper (Cu) or the like.

[0015] (2) Electrode body The electrode body 20 is a power generating element of the lithium ion secondary battery 1. As shown in Fig. 2, the electrode body 20 includes a positive electrode plate 30, a negative electrode plate 40, and a separator 50. The electrode body 20 shown in Fig. 2 is a wound electrode body. This wound electrode body is produced by stacking the positive electrode plate 30, the negative electrode plate 40, and the separator 50 to form a long strip-shaped laminate, and then winding the laminate. However, the structure of the electrode body 20 is not particularly limited, and may be any other conventionally known structure (such as a laminated electrode body).

[0016] The positive electrode plate 30 includes a positive electrode core 32, which is a metal foil having electrical conductivity, and a positive electrode active material layer 34 applied to the surface of the positive electrode core 32. Aluminum (Al) or the like is used for the positive electrode core 32. The positive electrode active material layer 34 is a composite layer containing a positive electrode active material, a conductive material, a binder, and the like. The positive electrode active material is a lithium transition metal composite oxide containing at least one of nickel (Ni) and cobalt (Co). Examples of such lithium transition metal composite oxides include lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel manganese composite oxide, lithium manganese cobalt composite oxide, lithium nickel cobalt composite oxide, and lithium nickel manganese cobalt composite oxide. According to the manufacturing method of this embodiment, Ni and / or Co can be efficiently recovered from a recovery target containing such a lithium transition metal composite oxide. Examples of the conductive material include carbon materials such as acetylene black and graphite. Examples of the binder include resin materials such as polyvinylidene fluoride (PVdF).

[0017] On the other hand, the negative electrode plate 40 includes a negative electrode core 42, which is a metal foil having electrical conductivity, and a negative electrode active material layer 44 applied to the surface of the negative electrode core 42. The negative electrode core 42 is made of copper (Cu) or the like. The negative electrode active material layer 44 is a composite layer containing a negative electrode active material, a binder, a thickener, and the like. Examples of the negative electrode active material include carbon materials such as graphite, hard carbon, and soft carbon. Other examples of the negative electrode active material include lithium titanate (LTO), silicon carbide, a composite containing carbon and silicon, and silicon oxide (SiO X ) The binder may be a resin material such as styrene butadiene rubber (SBR). The thickener may be a resin material such as carboxymethyl cellulose (CMC).

[0018] The separator 50 is an insulating sheet interposed between the positive electrode plate 30 and the negative electrode plate 40. For example, a resin material such as polyethylene (PE), polypropylene (PP), polyester, cellulose, or polyamide is used for the separator 50. A heat-resistant layer containing an inorganic filler may be formed on the surface of the separator 50. Examples of such inorganic fillers include inorganic oxides such as aluminum oxide, magnesium oxide, silicon oxide, and titanium oxide; nitrides such as aluminum nitride and silicon nitride; metal hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; and clay minerals such as mica, talc, boehmite, zeolite, apatite, and kaolin.

[0019] (3) Electrolyte The electrolyte is present between the positive electrode plate 30 and the negative electrode plate 40. This allows charge carriers (Li ions) to move between the positive electrode plate 30 and the negative electrode plate 40. Examples of the electrolyte include a non-aqueous electrolyte solution and a gel electrolyte. Note that the electrolyte may be any electrolyte that can be used in a lithium ion secondary battery without any particular limitation, and does not limit the technology disclosed herein.

[0020] The lithium ion secondary battery 1 has been described above as an example of the object of collection in the manufacturing method according to the present embodiment. However, the manufacturing method disclosed herein is not limited to the method in which the lithium ion secondary battery 1 having the above-mentioned configuration is the object of collection. For example, at the manufacturing site of the lithium ion secondary battery, a part of the positive electrode plate may be cut off when the electrode body is manufactured. This cut part of the positive electrode plate (process waste material) may also contain Ni or Co, and therefore may be the object of collection in the manufacturing method disclosed herein. In addition, at the manufacturing site of the lithium ion secondary battery, some defect may occur in the electrode body after manufacture, and it may become unusable in the product. Such an electrode body may also be the object of collection because it may contain Ni or Co. In other words, the object of collection in the manufacturing method disclosed herein is not particularly limited to a specific structure as long as it contains at least one of Ni and Co as a valuable metal.

[0021] 2. Manufacturing method of battery materials The manufacturing method of the battery material according to this embodiment will be described below. Fig. 3 is a flow chart for explaining the manufacturing method according to this embodiment. Fig. 4 is a flow chart for explaining the solvent extraction step in Fig. 3 in detail.

[0022] As shown in Fig. 3, the method for producing a battery material according to this embodiment includes a preparation step S10, an acid leaching step S40, a neutralization precipitation step S50, a solid-liquid separation step S60, and an ammonia leaching step S70. The method for producing a battery material disclosed herein may further include a roasting step S20, a selection step S30, a solvent extraction step S80, a Li crystallization step S90, a precursor preparation step S100, and an active material production step S110. The manufacturing method disclosed herein may further include other steps at any stage, and the other manufacturing processes may be the same as those of the conventional method. Each step will be described below.

[0023] (1) Preparation process S10 In the preparation step S10, a collection target containing at least one of Ni and Co is prepared. As described above, the "collection target" in the technology disclosed herein may contain at least one of Ni and Co. In other words, the collection target is not limited to completed lithium ion secondary batteries, but includes process waste materials and defective parts (electrode bodies, etc.). Details of the collection target have already been described, so a duplicated description will be omitted.

[0024] (2) Roasting process S20 In the roasting step S20, the object to be recovered is heated at a predetermined temperature. This allows the liquid components (electrolyte, etc.) in the object to be recovered to be removed, and the resin components (binder, separator, etc.) to be carbonized. Furthermore, when a charged lithium ion secondary battery 1 is to be recovered, the function as a battery can be stopped by carrying out the roasting step S20. This allows the subsequent steps to be carried out safely. As for the method of the roasting step S20, any technique used in conventional recovery techniques can be used without particular limitation, and since it does not characterize the technique disclosed herein, a detailed description will be omitted.

[0025] The roasting step S20 is not essential and can be omitted as necessary. For example, there are cases where a recovery target that does not require removal of liquid components and does not require stopping the function of a battery, such as process waste of a positive electrode plate 30, is prepared in the preparation step S10. In this case, valuable metals can be efficiently recovered even if the roasting step S20 is omitted.

[0026] (3) Sorting process S30 In the sorting step S30, each component contained in the object to be collected is sorted. The sorting step S30 may be carried out by a conventional method, for example, by screening or visual inspection. For example, when the object to be collected is a process waste of a positive electrode plate 30, the positive electrode core 32 may be selected from the process waste and removed from the object to be collected. When the object to be collected is an electrode body 20, the negative electrode plate 40 may be removed from the object to be collected in addition to the positive electrode core 32. When the object to be collected is a lithium-ion secondary battery 1, the case 10 may be removed from the object to be collected in addition to the positive electrode core 32 and the negative electrode plate 40. This reduces the content of other metals (Al, Cu, etc.) in the object to be collected, which contributes to improving the recovery efficiency of valuable metals (Co, Ni).

[0027] In addition, in the sorting step S30, the objects to be collected may be subjected to a crushing process as necessary. This can improve the efficiency of sorting each component. For example, when the objects to be collected are lithium-ion secondary batteries 1, it is preferable to crush the case 10 and the electrode body 20. This makes it easier to remove the case 10, the positive electrode core 32, and the negative electrode plate 40 from the objects to be collected.

[0028] Moreover, the sorting step S30 is not a step intended to completely remove other metal components such as Al and Cu from the object to be recovered. Although details will be described later, even if other metal components remain in the object to be recovered, valuable metals (Ni and / or Co) can be sufficiently separated from other metal components in subsequent steps (e.g., neutralization precipitation step S50, ammonia leaching step S70). That is, the sorting step S30 can be omitted as necessary. For example, in the case of an object to be recovered that has a low content of other metal components (such as process waste of positive electrode plate 30), valuable metals can be efficiently recovered even if the sorting step S30 is omitted.

[0029] (4) Acid leaching process S40 In the acid leaching step S40, the object to be recovered after the preparation step S10 (or the roasting step S20 or the sorting step S30) is immersed in an acid solution. As a result, valuable metals (Ni and / or Co) in the object to be recovered are dissolved in the acid solution. In addition to valuable metals, other metal materials (such as Al) may also be dissolved in the acid solution in the acid leaching step S40. That is, the acid solution that has been subjected to the acid leaching step S40 (hereinafter also referred to as the "acid leaching solution") may contain, for example, Li, Al, Cu, Co, Ni, Mn, etc. In addition, the procedure for acid leaching may be a conventionally known procedure without any particular restrictions. As an example, the pH of the acid solution used in the acid leaching step S40 is preferably -1.5 to 1.5 (more preferably -0.5 to 0.5). As a result, the metal components in the object to be recovered can be suitably dissolved. Specific examples of the acid solution include inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid, and organic acids such as citric acid, ascorbic acid, oxalic acid, and acetic acid. In the acid leaching step S40, a reducing agent such as hydrogen peroxide can be added in addition to the acid solution. This improves the dissolution rate of the object to be recovered in the acid solution, and the acid leaching step S40 can be shortened. In the acid leaching step S40, it is preferable to perform a filtration process on the acid leaching solution after acid leaching. This allows undissolved components (carbon components, etc.) to be efficiently removed. The temperature of the acid solution is preferably 50°C or higher (more preferably 55°C or higher, particularly preferably 60°C or higher). This allows the acid leaching step S40 to be shortened. The upper limit of the temperature of the acid solution is not particularly limited, and may be 90°C or lower, 85°C or lower, or 80°C or lower. The concentration of Ni and Co (the sum of Ni and Co) in the acid leaching solution after the acid leaching step S40 is not particularly limited, but the higher the concentration, the more preferable it is from the viewpoint of productivity. Therefore, the concentration of Ni and Co (the sum of Ni and Co) in the acid leaching solution is preferably 1.0 mol / L to 2.0 mol / L. The concentration of Ni and Co (the sum of Ni and Co) in the acid leaching solution can be determined by ICP analysis.

[0030] (5) Neutralization and precipitation process S50 In the neutralization precipitation step S50, a neutralizing agent is added to the acid leaching solution obtained in the acid leaching step S40 to increase the pH of the acid leaching solution. This causes Al contained in the acid leaching solution to precipitate as hydroxide (Al(OH)3). As a result, a metal solution from which Al has been removed can be obtained from the acid leaching solution containing Li, Al, Cu, Co, Ni, Mn, etc. In addition, an alkaline solution having a pH of 11 to 15 (preferably pH 12 to 14) can be used as the neutralizing agent used in the neutralization precipitation step S50. In addition, specific examples of the neutralizing agent include an aqueous sodium hydroxide solution and calcium hydroxide. Among them, it is preferable that the neutralizing agent contains an aqueous sodium hydroxide solution. The concentration of the neutralizing agent is not particularly limited, but a higher concentration is preferable from the viewpoint of productivity. Therefore, the concentration of the neutralizing agent is preferably 10 to 30 wt%.

[0031] The pH adjusted in the neutralization precipitation step S50 is preferably pH 5.0 or more, more preferably pH 5.1 or more, and more preferably pH 5.6 or more. When the pH of the acid leaching solution is low (typically less than pH 4.5), Al in the acid leaching solution is less likely to form hydroxides. In other words, Al is less likely to be separated from the acid leaching solution. As the pH of the acid leaching solution increases, Al in the acid leaching solution can be precipitated as Al hydroxide and precipitated. In other words, Al can be more suitably separated from the acid leaching solution. On the other hand, the pH adjusted in the neutralization precipitation step S50 is not particularly limited, but as the pH increases, some of Ni and Co in the acid leaching solution may also form hydroxides and precipitate in the metal solution. Therefore, the pH adjusted in the neutralization precipitation step S50 is preferably pH 6.5 or less, and more preferably pH 6.2 or less. In addition, although details will be described later, even if some of Ni and Co are precipitated, Ni and Co can be separated from the precipitate in the subsequent step (ammonia leaching step S70).

[0032] (6) Solid-liquid separation process S60 In the solid-liquid separation step S60, the metal solution after the neutralization precipitation step S50 and the precipitate are subjected to solid-liquid separation. This makes it possible to obtain the precipitate and the metal solution containing valuable metals (Ni and / or Co) and other metal components. Since the solid-liquid separation method can be a conventionally known method, a detailed description is omitted here. The metal solution obtained in the solid-liquid separation step S60 can be subjected to each recovery step (solvent extraction step S80) described later depending on the metal components contained in the metal solution, although this is not particularly limited thereto, to recover each metal component contained in the metal solution.

[0033] As described above, in the neutralization precipitation step S50, Al in the acid leaching solution can be precipitated as hydroxide, while part of Ni and / or Co also forms hydroxide, and these hydroxides can also precipitate in the metal solution like the hydroxide of Al. That is, the precipitate obtained in the solid-liquid separation step S60 may contain valuable metals (Ni and / or Co) as hydroxides. In order to recover valuable metals (Ni and / or Co) from such precipitates, for example, it is considered to return the precipitate to the acid leaching solution obtained in the acid leaching step S40 and dissolve it. However, in this case, Al accumulates in the acid leaching solution (in other words, the Al concentration in the acid leaching solution increases), which leads to a decrease in the yield of valuable metals (Ni and / or Co), which is not preferable. Here, as shown in FIG. 3, this embodiment is characterized by further comprising an ammonia leaching step S70 in addition to the neutralization precipitation step S50 and the solid-liquid separation step S60. This allows the recovery efficiency of valuable metals (Ni and / or Co) to be significantly improved. A specific description will be given below.

[0034] (7) Ammonia leaching process S70 In the ammonia leaching step S70, the precipitate precipitated in the neutralization precipitation step S50 and obtained by solid-liquid separation in the solid-liquid separation step S60 is immersed in an ammonia solution. This separates Ni and / or Co from the precipitate, and an ammonia solution in which Ni and / or Co are dissolved (hereinafter referred to as an "ammonia leaching solution") can be obtained. In detail, hydroxides of Ni and Co typically form ammine complexes in the ammonia solution. Such ammine complexes are dissolved in the ammonia solution. On the other hand, Al (and Al hydroxide) does not form ammine complexes in the ammonia solution, and typically remains as a residue (precipitate) as Al hydroxide (Al(OH)3). This allows the valuable metals (Ni and / or Co) in the precipitate to be selectively recovered. In this specification, the "ammonia solution" refers to an aqueous solution containing ammonium ions in water as a solvent.

[0035] The ammonia solution may be, for example, a commercially available product (ammonia water), or may be a solution in which at least a solvent containing water and an ammonia salt are dissolved. As the ammonia salt used in the ammonia solution, for example, ammonium hydroxide (NH4OH), ammonium sulfate ((NH4)2SO4), ammonium carbonate ((NH4)2CO3), ammonium hydrogen carbonate (NH4HCO3), ammonium chloride (NH4Cl), ammonium fluoride (NH4F), etc. may be appropriately used. These compounds may be used alone or in combination of two or more.

[0036] In some preferred embodiments, the ammonia solution preferably contains at least one selected from the group consisting of ammonium sulfate, ammonium chloride, and ammonium acetate. These have the role of a so-called pH buffer for the ammonia solution. In more detail, the pH of the ammonia solution can be lowered. By lowering the pH of the ammonia solution, the dissolution of Al in the ammonia solution is suppressed, and Ni and Co can be suitably dissolved selectively in the ammonia solution by suitably forming ammine complexes with Ni and Co. Furthermore, according to the above-mentioned configuration, the ammonia concentration of the ammonia solution can be increased, so that Ni and Co can be suitably formed ammine complexes and suitably dissolved in the ammonia solution. Therefore, Ni and Co in the precipitate can be suitably leached (recovered) selectively into the ammonia solution.

[0037] In the ammonia leaching step S70, the pH of the ammonia solution is preferably adjusted to pH 9.0 to 11.5, and more preferably adjusted to pH 9.5 to 10.0, before the ammonia leaching. As the pH of the ammonia solution decreases, Ni and Co preferably form ammine complexes, and these valuable metals (Ni and / or Co) can be preferably recovered. In addition, if the pH is too high (typically exceeding pH 11.5), a portion of the Al in the precipitate becomes a hydroxide complex ([Al(OH)4] ― ) and begins to dissolve in the ammonia solution.

[0038] In the ammonia leaching step S70, the ammonia concentration in the ammonia solution is preferably 10 wt% or more, and more preferably 20 wt% or more. As the ammonia concentration increases, Ni and / or Co favorably form ammine complexes, so that valuable metals (Ni and / or Co) can be more efficiently recovered from the precipitate. On the other hand, in view of the high volatility of ammonia, the upper limit of the ammonia concentration in the ammonia solution is, but is not limited to, for example, 35 wt% or less, and preferably 30 wt% or less.

[0039] Since the ammonium ions in the ammonia solution are used to form ammine complexes with Ni and / or Co, the pH and free ammonia concentration decrease as the ammonia leaching process progresses, compared to the initial ammonia solution (hereinafter also referred to as the "initial solution"). Therefore, additional ammonia solution may be added during the ammonia leaching process S70. This allows the pH and ammonia concentration in the ammonia solution to be kept within a suitable range, and the valuable metals (Ni and / or Co) in the precipitate can be separated more efficiently. The pH of the additional ammonia solution may be the same as or higher than the pH of the initial solution. The ammonia concentration of the additional ammonia solution may be the same as or higher than the ammonia concentration of the initial solution. The composition of the additional ammonia solution may be the same as or different from the initial solution.

[0040] The temperature of the mixed liquid in the ammonia leaching step S70 is not particularly limited, but is preferably 25° C. or higher, more preferably 40° C. or higher, and particularly preferably 60° C. or higher. This allows the time of the ammonia leaching step S70 to be shortened. On the other hand, the upper limit of the temperature of the mixed liquid is not particularly limited, but is preferably 100° C. or lower, more preferably 90° C. or lower, and particularly preferably 80° C. or lower.

[0041] The leaching time in the ammonia leaching step S70 is not particularly limited because it may vary depending on, for example, the ammonia concentration in the reaction solution and the reaction temperature, but is preferably about 0.5 hours or more, more preferably 1 hour or more, and particularly preferably 2 hours or more. On the other hand, from the viewpoint of productivity, the leaching time is preferably about 8 hours or less, more preferably 6 hours or less, and particularly preferably 4 hours or less. Although not particularly limited, it is preferable to perform the ammonia leaching step S70 while stirring the ammonia solution. This increases the contact area between the precipitate and the ammonia solution, so that valuable metals (Ni and / or Co) can be efficiently dissolved in the ammonia solution. Therefore, the leaching time can be shortened.

[0042] After the ammonia leaching step S70, the ammonia leaching solution and the residue are subjected to solid-liquid separation. This makes it possible to obtain an ammonia leaching solution in which Ni and / or Co are dissolved in the ammonia solution. The use of the ammonia leaching solution is not particularly limited, but it can be suitably used, for example, as an alkaline solution in the precursor preparation step S100 described later. In this case, the ammonia leaching solution can be used as it is as an alkaline solution without undergoing a step such as washing. That is, there is no loss of valuable metals due to washing or re-extraction. In addition, the valuable metals (Ni and / or Co) in the ammonia leaching solution can also be used as a positive electrode active material precursor. Therefore, the recovery rate of valuable metals (Ni and / or Co) contained in the recovery target can be improved.

[0043] As described above, in the manufacturing method disclosed herein, the precipitate obtained in the neutralization precipitation step is leached in an ammonia solution, so that valuable metals (Ni and / or Co) in the precipitate can be recovered. Conventionally, valuable metals (Ni and / or Co) are separated by performing a neutralization precipitation step on the acid leaching solution that has been subjected to the acid leaching step. At this time, since a part of the valuable metals (Ni and / or Co) may also precipitate together with Al as a precipitate, there is a problem that a loss of valuable metals occurs, and in order to reduce such loss, the pH cannot be sufficiently increased in the neutralization precipitation step in an attempt to suppress the precipitation of valuable metals, so that Al cannot be sufficiently separated from the acid leaching solution. On the other hand, in the manufacturing method disclosed herein, valuable metals (Ni and / or Co) can be separated from the precipitate by the ammonia leaching step, and the recovery rate of such valuable metals can be improved.

[0044] (8) Solvent extraction process S80 In the solvent extraction step S80, each metal component (Ni and / or Co) is extracted from the metal solution using a solvent extraction method. In addition, in the solvent extraction step S80, other metal components (Al, etc.) remaining in the metal solution can also be separated. Specifically, the solvent extraction step S80 in this embodiment includes a Co extraction step S81 and a Ni extraction step S82, as shown in FIG. 4. This makes it possible to prepare each of a Co solution and a Ni solution. However, in the solvent extraction step S80, steps can be added, changed, or deleted as appropriate depending on the metal components contained in the metal solution. A specific description will be given below.

[0045] (8-1) Co extraction process S81 In the Co extraction step S81, an organic solvent (first extraction liquid) that has high extractability for Co and low extractability for Li, Al, Cu, and Ni is added to the metal solution. This separates Co from the metal solution, and a Co solution in which Co is dissolved in the first extraction liquid can be obtained. Specific examples of the second extraction liquid include phosphonic acid esters such as 2-ethylhexyl phosphonic acid 2-ethylhexyl (PC-88A). The first extraction liquid may be a mixture or dilution of these extractants. Then, in the Co extraction step S81, the metal solution and the first extraction liquid are stirred and suspended. This dissolves Co in the metal solution in the first extraction liquid. Then, by leaving the two liquids to separate, a Co solution in which Co is dissolved in the first extraction liquid and a metal solution from which Co has been removed can be obtained.

[0046] In the Co extraction step S81, a back extraction process may be performed on the extracted Co solution (first extract containing Co). In this back extraction process, first, the Co solution (organic phase) and an acidic aqueous solution are stirred and mixed in a mixer or the like. Then, the mixture is left to stand until the two liquids are separated. In this way, an aqueous Co solution can be obtained. Examples of the acidic aqueous solution used in the back extraction process include sulfuric acid, hydrochloric acid, and the like (particularly sulfuric acid).

[0047] (8-2)Ni extraction process S82 In the Ni extraction step S82, an organic solvent (second extraction liquid) that has high extractability for Ni and low extractability for Li, Al, and Cu is added to the metal solution. This separates Ni from the metal solution, and a Ni solution in which Ni is dissolved in the second extraction liquid can be obtained. Specific examples of the third extraction liquid include carboxylic acid extractants such as neodecanoic acid and naphthenic acid. In addition, a back extraction process may also be performed on the Ni solution after extraction (second extraction liquid containing Ni). This allows an aqueous Ni solution to be obtained. The procedure for the back extraction process has already been described, so a duplicate description will be omitted.

[0048] (9) Li crystallization process S90 In the Li crystallization step S90, crystals of a Li compound are precipitated from the metal solution after the solvent extraction step S80. In the Li crystallization step S90, a conventionally known crystallization process can be adopted without any particular limitation. For example, in the Li crystallization step S90, sodium carbonate may be added to the metal solution. This allows lithium carbonate (Li2CO3) crystals to be precipitated. The Li compound generated in the Li crystallization step S90 is not limited to lithium carbonate. For example, lithium hydroxide (LiOH) may be generated as the Li compound as necessary. In the generation of this lithium hydroxide, first, the lithium carbonate precipitated from the metal solution is dissolved (or suspended) in a predetermined solvent. Then, calcium hydroxide is added to this solution. After that, the solvent is evaporated and removed as necessary. This allows lithium hydroxide crystals to be precipitated. However, in the manufacturing method disclosed herein, the Li crystallization step S90 is not essential. For example, when Li is not contained in the metal solution (in other words, when Li is not contained in the recovery target), the Li crystallization step S90 can be omitted.

[0049] (10) Precursor preparation process S100 In the precursor preparation step S100, a positive electrode active material precursor (metal composite hydroxide) is prepared. In the precursor preparation step S100, a conventionally known method (such as a crystallization method) can be adopted without any particular limitation. For example, an aqueous solution containing a metal element source (typically a water-soluble ionic compound) is prepared. Next, the aqueous solution containing the prepared metal element source and an alkaline solution (such as an ammonia solution) are mixed in a reaction tank, and the mixture is stirred while controlling the pH of the mixture, thereby co-precipitating and crystallizing particles of the metal composite hydroxide in the reaction tank. Here, in this embodiment, the ammonia leaching solution obtained in the ammonia leaching step S70 can be suitably used as the alkaline solution. The ammonia leaching solution contains Ni and / or Co in the ammonia solution. Therefore, the ammonia leaching solution does not need to be treated, such as washed, and can be used as it is as the alkaline solution in the precursor preparation step S100. Therefore, Co and Ni in the ammonia solution can also be crystallized as a positive electrode active material precursor. That is, the valuable metals (Ni and / or Co) recovered from the precipitate in the ammonia leaching step S70 can be used efficiently.

[0050] As described above, in the precursor preparation step S100, crystallization is performed while controlling the pH of the mixed solution. At this time, an alkaline solution (such as an aqueous NH3 solution or an aqueous NaOH solution) for adjusting the pH can be dropped into the reaction tank. The amount of Ni and Co in the metal solution obtained in the ammonia leaching step S70 can be determined by ICP analysis. For this reason, metal components such as Ni, Co, or Mn may be added depending on the composition of the target positive electrode active material. Such metal components may be added in the form of metal sulfates, hydrates, etc. In this case, various metal components obtained in the solvent extraction step S80 may be used as the metal components.

[0051] (11) Active material generation step S110 In the active material generating step S110, a battery material (positive electrode active material) is generated using the metal compound obtained in the precursor producing step S100 and a Li compound (e.g., Li2CO3, etc.). For example, the positive electrode active material precursor (metal composite hydroxide) obtained in the precursor producing step S100 is mixed with a Li compound, and the mixture is fired. This makes it possible to produce a positive electrode active material (lithium transition metal composite oxide) for a lithium ion secondary battery. Note that the Li compound obtained in the Li crystallization step S90 may be used as the Li compound.

[0052] The manufacturing method of the battery material according to the present embodiment has been described above. As described above, in the manufacturing method according to the present embodiment, an ammonia leaching step is performed in which the precipitate obtained by the neutralization precipitation step is immersed in an ammonia solution. As a result, Ni and / or Co contained in the precipitate can be dissolved in the ammonia solution to obtain an ammonia leaching solution containing Ni and / or Co. Therefore, the valuable metals (Ni and / or Co) precipitated as part of the precipitate during the neutralization precipitation step can be suitably recovered (manufactured), in other words, the recovery rate of the valuable metals can be improved. In addition, the ammonia leaching solution obtained by the manufacturing method disclosed herein can be used as it is in the precursor preparation step S100 without performing a step such as washing. As a result, the valuable metals (Ni and / or Co) contained in the ammonia leaching solution can be used as a positive electrode active material precursor. Therefore, the valuable metals (Ni and / or Co) can be efficiently recovered, and the recovery rate of the valuable metals can be significantly improved.

[0053] 3. Other embodiments An embodiment of the technology disclosed herein has been described above. Note that the technology disclosed herein is not limited to the above embodiment, and includes other embodiments in which various configurations are modified. Other examples of the embodiment of the technology disclosed herein will be described below.

[0054] (a) Changes in the solvent extraction process The specific processing procedure in the solvent extraction step S80 can be changed as appropriate. For example, the solvent extraction step S80 in the above embodiment includes a Co extraction step and a Ni extraction step. This allows the Co solution and the Ni solution to be extracted separately. However, in the solvent extraction step S80, Ni and Co may be extracted simultaneously. This allows the manufacturing efficiency to be improved by shortening the process.

[0055] In addition, the steps that can be included in the solvent extraction step S80 are not limited to the Co extraction step and Ni extraction step described above. For example, when the metal solution further contains manganese (Mn) as a metal component, the solvent extraction step S80 can further include a Mn extraction step for extracting Mn from the metal solution. The means for the Mn extraction step is not particularly limited, but it can be performed by adding an organic solvent (third extraction liquid) that has high extractability for Mn and low extractability for Li, Al, Cu, Co, and Ni to the metal solution. As the third extraction liquid, a phosphate ester extractant, an oxime extractant, or the like can be used. A specific example of a phosphate ester extractant is di-2-ethylhexyl phosphoric acid (D2EHPA), etc. Specific examples of oxime extractants include 2-hydroxy-5-nonylacetophenone oxime (LIX84), 5-dodecylsalicylardoxime (LIX860), and 5-nonylsalicylaldoxime (ACORGA M5640). The third extractant may be a mixture or dilution of these extractants. The Mn solution after extraction (third extractant containing Mn) may also be subjected to back-extraction treatment. The specific extraction method and back-extraction treatment method may be the same as those in the Co extraction step S81 and Ni extraction step S82 described above, and therefore will not be described here.

[0056] (b) Omission of the solvent extraction process Moreover, according to the manufacturing method disclosed herein, the solvent extraction step S80 can be omitted. Specifically, as described above, in the technology disclosed herein, Al can be separated from the metal solution by the neutralization precipitation step S50. This can result in a solution containing valuable metals (Ni and / or Co) at high purity. Therefore, when a recovery target that does not contain Cu, such as process waste of the positive electrode plate 30, is used, a mixture of valuable metals (aqueous solution containing a metal element source) used in the precursor preparation step S100 can be obtained without carrying out the solvent extraction step S80.

[0057] On the other hand, when the metal solution contains Li, the following means can be given as an example of a means for recovering Li. First, when performing the roasting step S20, a non-metallic chlorine compound (such as HCl) is added to the recovery target and roasted. As a result, Li in the recovery target reacts with the non-metallic chlorine compound to generate LiCl. Next, a water leaching step is performed in which the recovery target after roasting is immersed in water. Since the above LiCl is a water-soluble compound, Li can be recovered simply by contacting the recovery target with water. As a result, while recovering (producing) Li in the metal solution, a mixture of valuable metals (aqueous solution containing a metal element source) used in the precursor production step S100 can be obtained without performing the solvent extraction step S80. That is, the description of the above embodiment is not intended to limit each step. In the manufacturing method disclosed herein, each step may be appropriately added, deleted, or changed as necessary.

[0058] (c) Addition of Li separation process In some embodiments, the metal solution after the solvent extraction step S80 may be subjected to a Li separation step. The Li separation step is a step of further removing Cu and Al from the metal solution to prepare a high-concentration Li solution. This allows a high-purity Li compound to be obtained in the Li crystallization step S90. The means for preparing the Li solution is not particularly limited, and it is preferable to appropriately adopt a conventionally known means such as a solvent extraction method or an ion exchange method. Instead of the Li concentration step, only evaporation of the solvent may be performed. Even in this case, a high-concentration Li solution can be obtained.

[0059] (d) Addition of Li enrichment process In addition, a Li concentration step may be performed on the metal solution after the Li separation step. In this Li concentration step, the Li solution is heated to evaporate the solvent. This makes it possible to obtain a high-concentration Li solution, thereby improving the crystallization efficiency in the Li crystallization step S90. This Li concentration step may be performed on a metal solution that has not been subjected to the Li separation step. In this case, a high-concentration Li solution can also be obtained.

[0060] [Test example] Test examples relating to the technology disclosed herein will be described below. Note that the contents of the test examples described below are not intended to limit the technology disclosed herein.

[0061] <Test Example 1: Study of pH during neutralization precipitation process> (Example 1) [Sample preparation] In this test, the positive electrode plate was used as the object to be collected, and the following process was carried out on the object to be collected. Specifically, the positive electrode plate used had a positive electrode core (Al foil) with a positive electrode active material layer applied to its surface. The positive electrode active material used in this test was lithium nickel cobalt manganese composite oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2) was used. The positive electrode plate was crushed and sieved through a 500 μm mesh sieve to obtain a powder for use as a test sample. When the powder for the test sample was analyzed by ICP, the mass ratio of Al to the total amount of Ni and Co in the sample was found to be 4 wt%.

[0062] [Acid leaching process] Next, the test sample was mixed with a mixture (pH 0.01) of sulfuric acid (H2SO4) (concentration 2 mol / L) as an acid solution and hydrogen peroxide (H2O2) (concentration 0.6 mol / L) as a reducing agent. The acid solution was then stirred at a stirring speed of 600 rpm for 6 hours while being maintained at 80°C. After stirring, the acid leachate was filtered, and the resulting acid leachate was analyzed by ICP to measure the amounts of Al, Ni, and Co. The ICP measurement results showed that the concentrations of Ni and Co (the sum of Ni and Co) in the acid leachate were 1.0 mol / L.

[0063] [Neutralization precipitation process] The acid leachate obtained above was maintained at 25°C, and a 10 wt% sodium hydroxide solution was dropped into the acid leachate while stirring at a stirring speed of 600 rpm. When the pH of the acid leachate reached 5.1, the dropping of sodium hydroxide was stopped. After the dropping was stopped, stirring was continued at a stirring speed of 600 rpm for 10 minutes, and it was confirmed that the pH did not change. Then, the metal solution and the precipitate were separated into solid and liquid by filtration.

[0064] (Example 2) In the neutralization precipitation step, the dropping of sodium hydroxide was stopped when the pH of the acid leaching solution reached 5.6. The rest of the procedure was the same as in Example 1.

[0065] (Example 3) In the neutralization precipitation step, the dropping of sodium hydroxide was stopped when the pH of the acid leaching solution reached 6.2. Except for this, the same procedure as in Example 1 was followed.

[0066] [Residual rate in metal solution during neutralization precipitation process] The residual ratios of valuable metals (Ni, Co) and Al in the metal solution of each example after the neutralization precipitation step were calculated. Specifically, first, the metal solution was subjected to ICP to measure the amounts of Ni, Co, and Al in the metal solution. Then, based on the following formulas (1) and (2), the residual ratios of Ni and Co in the metal solution and the residual ratio of Al in the metal solution were calculated, respectively, compared to the acid leachate of each example (i.e., before the neutralization precipitation step). The results are shown in Table 1. Ni, Co remaining rate in metal solution (%) = {(amount of Ni in metal solution + amount of Co in metal solution) / (amount of Ni in acid leachate + amount of Co in acid leachate) × 100 ... (1) Al remaining rate in metal solution (%) = (Amount of Al in metal solution / Amount of Al in acid leachate) × 100…(2)

[0067] [Ni,Co ratio in the precipitate during the neutralization precipitation process] In addition, the ratio of the amount of valuable metals (Ni, Co) to the amount of Al in the precipitate for each example after the neutralization precipitation process was calculated. Specifically, first, the amount of each of Ni, Co, and Al in the precipitate was measured by performing ICP on the precipitate after the neutralization precipitation process. Then, the ratio of the amount of valuable metals (Ni, Co) in the precipitate for each example was calculated based on the following formula (3). The results are shown in Table 1. Ni,Co ratio in precipitate (%) = {(Ni mass in precipitate + Co mass in precipitate) / Al mass in precipitate} × 100…(3)

[0068] [Table 1]

[0069] As shown in the results in Table 1, in Example 1, where the pH during precipitation was 5.1 in the neutralization precipitation step, the Al residual rate in the metal solution was 1.5%. This shows that the Al contained in the acid leaching solution was roughly neutralized and precipitated when the pH of the acid leaching solution was neutralized to 5.1. Comparing Examples 1 to 3, the higher the pH during precipitation, the lower the Al residual rate in the metal solution, and Example 3, where the pH during precipitation was 6.2, had the lowest Al residual rate in the metal solution. On the other hand, Example 3 had the lowest Ni,Co residual rate in the metal solution and the highest Ni,Co ratio in the precipitate.

[0070] <Test Example 2: Study of the ammonia leaching process> (Example 4) [Ammonia leaching process] Ammonia leaching was performed on the precipitate obtained by the neutralization precipitation process described above. Specifically, first, ammonia water (ammonia concentration in the solution: 1.5 wt%) with a pH of 11.2 was prepared as an ammonia solution. Then, the precipitate according to Example 1 obtained by the neutralization precipitation process described above was placed in the ammonia solution. Then, the ammonia solution was stirred for 2 hours at a stirring speed of 600 rpm while being maintained at 80°C. If a decrease in pH in the solution was observed during stirring, the pH was adjusted to 11.2 by adding additional ammonia solution with an ammonia concentration of 28 wt%. After stirring, the ammonia leaching solution and the residue were separated into solid and liquid by filtration.

[0071] (Example 5) In Example 5, the ammonia leaching step was carried out in such a manner that the pH of the ammonia solution was 12.1 (ammonia concentration in the solution: 10.0 wt%). The rest of the procedure was the same as in Example 4.

[0072] (Example 6) In Example 6, 2 mol / L of ammonium sulfate ((NH4)2SO4) was added as a pH buffer to ammonia water with a pH of 12.1 (ammonia concentration in the solution of 10.0 wt%) as the ammonia solution. As a result, the ammonia leaching process was performed with the pH of the ammonia solution at 9.6. The rest of the procedure was the same as in Example 4.

[0073] (Examples 7 to 9) In Example 7, the precipitate from Example 2 was used in an ammonia leaching step, otherwise similar to Example 4. In Example 8, the precipitate from Example 2 was used in an ammonia leaching step, otherwise similar to Example 5. In Example 9, the precipitate from Example 2 was used in an ammonia leaching step, otherwise similar to Example 6.

[0074] (Example 10 to Example 12) In Example 10, the precipitate from Example 3 was used in an ammonia leaching step, otherwise similar to Example 4. In Example 11, the precipitate from Example 3 was used in an ammonia leaching step, otherwise similar to Example 5. In Example 12, the precipitate from Example 3 was used in an ammonia leaching step, otherwise similar to Example 6.

[0075] (Example 13) In Example 13, the ammonia leaching step was carried out while maintaining the temperature of the ammonia solution at 25° C., except for this, the procedure was the same as in Example 12.

[0076] [Ni, Co remaining rate in residue] The residual rate of valuable metals (Ni, Co) in the residue for each example after the ammonia leaching process was calculated. Specifically, first, the amount of each of Ni, Co, and Al in the residue was measured by performing ICP on the residue. Then, based on the following formula (4), the ratio of the amount of valuable metals (Ni, Co) in the residue to the amount of Al in the residue for each example was calculated. The results are shown in Table 2. Ratio of Ni, Co in residue (%) = {(amount of Ni in residue + amount of Co in residue) / amount of Al in residue} × 100 ... (4)

[0077] [Al leaching rate in ammonia leaching solution] The Al leaching rate in the ammonia leachate for each example after the ammonia leaching process was calculated. Specifically, first, the amount of Al in the ammonia leachate was measured by performing ICP on the ammonia leachate. Then, the ratio of the amount of Al in the ammonia leachate to the amount of Al in the residue for each example was calculated based on the following formula (5). The results are shown in Table 2. Al leaching rate in ammonia leaching solution (%) = (Amount of Al in ammonia leaching solution / Amount of Al in residue) × 100 ... (5)

[0078] [Table 2]

[0079] As shown in the results of Table 2, in Example 4, in which the pH of the ammonia solution was 11.2, the Ni,Co ratio in the residue was significantly reduced compared to the Ni,Co ratio in the precipitate (i.e., before the ammonia leaching process). In addition, the Al leaching rate in the ammonia leaching solution in Example 4 was 0.2%. This shows that in Example 4, Ni and Co in the precipitate were preferably and selectively recovered by ammonia leaching. On the other hand, as shown in Example 5, when the pH of the ammonia solution was 12.1, the recovery effect of Ni and Co in the precipitate by ammonia leaching was observed, but the Al leaching rate in the ammonia leaching solution was higher than that in Example 4. In addition, when Examples 4 to 6 were compared, Example 6, in which ammonium sulfate was included in the ammonia solution, had the lowest Al leaching rate in the ammonia leaching solution and the lowest Ni,Co ratio in the residue.

[0080] As shown in the results of Examples 7 to 9 and Examples 10 to 12, it can be seen that the same results as in Examples 4 to 6 can be obtained when using the precipitates of Examples 2 and 3, which have different pH during neutralization precipitation. The result of Example 13 shows that Ni and Co can be selectively recovered from the precipitate even when the temperature of the ammonia solution is 25°C, and Al leaching into the ammonia leachate is also suppressed. Comparing Example 12 and Example 13, the Ni and Co ratios in the residue were lower in Example 12, where the temperature of the ammonia solution was 80°C.

[0081] Although the technology disclosed herein has been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. In other words, the technology disclosed herein includes the embodiments described in items 1 to 7 below.

[0082] <Item 1> A preparation step of preparing a recovery target containing at least one of Ni and Co; an acid leaching step of immersing the recovery target in an acid solution to obtain an acid leaching solution; a neutralization precipitation step of mixing the acid leachate with a neutralizing agent to obtain a precipitate; A solid-liquid separation step of separating the precipitate into solid and liquid; and an ammonia leaching step of immersing the separated precipitate in an ammonia solution containing ammonium ions to obtain an ammonia leaching solution containing at least one of the Ni and the Co. Manufacturing method for battery materials.

[0083] <Item 2> 2. The method for producing a battery material according to item 1, wherein the pH of the ammonia solution is adjusted to 9.0 to 11.5 and the ammonia leaching step is carried out.

[0084] <Item 3> 3. The method for producing a battery material according to item 1 or 2, wherein the ammonia solution contains at least one selected from the group consisting of ammonium sulfate, ammonium chloride, and ammonium acetate.

[0085] <Item 4> 4. The method for producing a battery material according to any one of items 1 to 3, further comprising a precursor preparation step of preparing a positive electrode active material precursor using the ammonia leaching solution obtained in the ammonia leaching step.

[0086] <Item 5> 5. The method for producing a battery material according to any one of items 1 to 4, wherein the ammonia leaching step is carried out at a temperature of the ammonia solution of 25 to 100°C.

[0087] <Item 6> 6. The method for producing a battery material according to any one of items 1 to 5, wherein in the neutralization precipitation step, the acid leaching solution is neutralized to a pH of 5.0 to 6.5.

[0088] <Item 7> 7. The method for producing a battery material according to any one of items 1 to 6, wherein the target to be recovered includes at least one selected from the group consisting of lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel manganese composite oxide, lithium manganese cobalt composite oxide, lithium nickel cobalt composite oxide, and lithium nickel manganese cobalt composite oxide. [Explanation of symbols]

[0089] 1. Lithium-ion secondary battery 10 Cases 12 Positive terminal 14 Negative terminal 20 Electrode body 30 Positive plate 32 Positive electrode core 34 Cathode active material layer 40 Negative plate 42 Negative electrode core 44 Negative electrode active material layer 50 Separator

Claims

1. A preparation step of preparing a recovery target containing at least one of Ni and Co; an acid leaching step of immersing the recovery target in an acid solution to obtain an acid leaching solution; a neutralization precipitation step of mixing the acid leachate with a neutralizing agent to obtain a precipitate; A solid-liquid separation step of separating the precipitate into solid and liquid; and an ammonia leaching step of immersing the separated precipitate in an ammonia solution containing ammonium ions to obtain an ammonia leaching solution containing at least one of the Ni and the Co. Manufacturing method for battery materials.

2. The method for producing a battery material according to claim 1, wherein the pH of the ammonia solution is adjusted to 9.0 to 11.5 and the ammonia leaching step is carried out.

3. 3. The method for producing a battery material according to claim 1, wherein the ammonia solution contains at least one selected from the group consisting of ammonium sulfate, ammonium chloride, and ammonium acetate.

4. The method for producing a battery material according to claim 1 or 2, further comprising a precursor preparation step of preparing a positive electrode active material precursor by using the ammonia leaching solution obtained in the ammonia leaching step.

5. 3. The method for producing a battery material according to claim 1, wherein the ammonia leaching step is performed at a temperature of the ammonia solution of 25 to 100° C.

6. 3. The method for producing a battery material according to claim 1, wherein the acid leaching solution is neutralized to a pH of 5.0 to 6.5 in the neutralization precipitation step.

7. 3. The method for producing a battery material according to claim 1, wherein the target to be recovered includes at least one selected from the group consisting of a lithium nickel composite oxide, a lithium cobalt composite oxide, a lithium nickel manganese composite oxide, a lithium manganese cobalt composite oxide, a lithium nickel cobalt composite oxide, and a lithium nickel manganese cobalt composite oxide.

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