Method for recovering active metals from lithium secondary batteries

Abstract

In a method for recovering active metals of a lithium secondary battery, a positive electrode active material mixture is prepared from a waste positive electrode of the lithium secondary battery. The positive electrode active material mixture is reacted with a reducing reaction gas to form a primary precursor mixture having a degree of reduction of a transition metal defined by equation 1 in the range of 0.24 to 1.6. A lithium precursor is recovered from the primary precursor mixture. The recovery rate of lithium can be increased by adjusting the degree of reduction of the transition metal.

Description

Technical Field

[0001] The present invention relates to a method for recovering active metals from lithium secondary batteries. More specifically, the present invention relates to a method for recovering active metals from waste positive electrodes of lithium secondary batteries. Background Art

[0002] Recently, secondary batteries have been widely used as power sources for mobile electronic devices such as camcorders, mobile phones, laptop computers, etc. and automobiles such as electric vehicles and hybrid vehicles. Lithium secondary batteries have attracted much attention among secondary batteries due to their advantages such as high operating voltage and energy density per unit weight, high charging rate, and compact size.

[0003] Lithium metal oxide can be used as an active material of a positive electrode of a lithium secondary battery. Lithium metal oxide may further contain a transition metal such as nickel, cobalt, manganese, and the like.

[0004] Since the above-mentioned high-cost valuable metals are used for the positive electrode active material, more than 20% of production cost is required to manufacture the positive electrode material. In addition, due to recent attention paid to environmental protection issues, a method for recycling the positive electrode active material is being studied.

[0005] Traditionally, a method of sequentially recovering valuable metals by leaching spent positive electrode active materials in strong acids such as sulfuric acid has been used, but wet processes can be disadvantageous in terms of regeneration selectivity and regeneration time, and can cause environmental pollution. Therefore, a method of recovering valuable metals using dry-based reactions is being studied.

[0006] For example, methods for regenerating or recovering lithium through dry reduction reactions are being studied, which requires precise control of reaction equipment and reaction conditions to improve the recovery rate of lithium.

[0007] For example, Korean Registered Patent Publication No. 10-0709268 discloses an apparatus and method for recycling waste manganese batteries and alkaline batteries, but does not provide a dry-based method for regenerating valuable metals with high selectivity and high yield. Summary of the invention

[0008] [Technical issues]

[0009] According to one aspect of the present invention, there is provided a method for recovering active metals of a lithium secondary battery with high efficiency and high purity.

[0010] [Technical means]

[0011] In a method for recovering active metals of a lithium secondary battery according to an embodiment of the present invention, a positive electrode active material mixture containing lithium-transition metal oxide is prepared from a waste positive electrode of a lithium secondary battery. The positive electrode active material mixture is reacted with a reducing reaction gas to form a primary precursor mixture having a degree of reduction of a transition metal defined by equation 1 in the range of 0.24 to 1.6. A lithium precursor is recovered from the primary precursor mixture:

[0012] [Equation 1]

[0013] Reduction degree of transition metal = (MeO phase fraction + lithium-transition metal oxide phase fraction) / (Me phase fraction)

[0014] (In Equation 1, Me includes Ni and Co, and the MeO phase fraction, the lithium-transition metal oxide phase fraction, and the Me phase fraction are determined by performing Rietveld crystal structure analysis on the X-ray diffraction ((XRD)) analysis peaks of the primary precursor mixture).

[0015] In some embodiments, the lithium-transition metal oxide may be represented by Chemical Formula 1:

[0016] [Chemical formula 1]

[0017] Li x Ni a Co b Mn c O y

[0018] (In chemical formula 1, 0 <x≤1.1,2≤y≤2.02,0<a<1,0<b<1,0<c<1,0<a+b+c≤1)。

[0019] In some embodiments, the reducing reaction gas may include hydrogen and a carrier gas, and a concentration of hydrogen in the reducing reaction gas may be in a range of 10 vol % to 40 vol %.

[0020] In some embodiments, the reaction temperature with the reducing reaction gas may be in the range of 400°C to 600°C.

[0021] In some embodiments, the primary precursor mixture may include primary lithium precursor particles and transition metal-containing particles, and the transition metal-containing particles may include Ni, Co, NiO, CoO, and MnO.

[0022] In some embodiments, the primary lithium precursor particles may include at least one of lithium hydroxide, lithium oxide, and lithium carbonate.

[0023] In some embodiments, recovering the lithium precursor may include washing the primary lithium precursor particles with water.

[0024] In some embodiments, the transition metal-containing particles may be selectively treated with an acid solution to recover the transition metal precursor in the form of an acid salt.

[0025] In some embodiments, the degree of reduction of the transition metal of the primary precursor mixture may be in the range of 0.24 to 1.0.

[0026] In some embodiments, in forming the primary precursor mixture, the cathode active material mixture may be reacted with a reducing reaction gas in a fluidized bed reactor.

[0027] [Effects of the invention]

[0028] According to the above exemplary embodiment, the lithium precursor can be recovered from the spent positive active material by a dry-based process using a dry reduction process. Therefore, the lithium precursor can be obtained with high purity without an additional process caused by a wet process.

[0029] In an exemplary embodiment, after the dry reduction process, the ratio of the transition metal oxide phase fraction to the transition metal phase fraction can be adjusted to provide an appropriate degree of reduction for lithium recovery. Thus, the recovery rate of the desired lithium precursor can be increased while effectively extracting lithium from the lithium transition metal oxide and preventing metal aggregation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic flow chart for describing a method of recovering active metals of a lithium secondary battery according to an exemplary embodiment. DETAILED DESCRIPTION

[0031] Embodiments of the present invention provide a method for recovering active metals from lithium secondary batteries with high purity and high yield using a dry reduction reaction.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, these embodiments are provided as examples, and the present invention is not limited to the specific embodiments described herein.

[0033] As used herein, the term "precursor" is used to generally refer to a compound containing a specific metal to provide the specific metal contained in an electrode active material.

[0034] Figure 1 is a schematic flow chart for describing a method for recovering active metals of a lithium secondary battery according to an exemplary embodiment. For convenience of description, Figure 1 A schematic diagram of the reactor and process flow is shown.

[0035] Reference Figure 1, a positive electrode active material mixture (e.g., a waste positive electrode active material mixture) can be prepared from the waste positive electrode of a lithium secondary battery (e.g., S10 process).

[0036] The lithium secondary battery can include an electrode assembly that includes a positive electrode, a negative electrode, and a separator layer interposed between the positive electrode and the negative electrode. The positive electrode can include a positive electrode active material layer coated on a positive electrode current collector, and the negative electrode can include a negative electrode active material layer coated on a negative electrode current collector.

[0037] For example, the positive electrode active material included in the positive electrode active material layer can include an oxide containing lithium and a transition metal.

[0038] In some embodiments, the positive electrode active material can include a compound represented by the following Chemical Formula 1.

[0039] [Chemical Formula 1]

[0040] Li x M1 a M2 b M3 c O y

[0041] In Chemical Formula 1, M1, M2, and M3 can be transition metals selected from Ni, Co, Mn, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, or B. In Chemical Formula 1, 0 < x ≤ 1.1, 2 ≤ y ≤ 2.02, 0 < a < 1, 0 < b < 1, 0 < c < 1, and 0 < a + b + c ≤ 1.

[0042] In some embodiments, the positive electrode active material can be an NCM-based lithium oxide including nickel, cobalt, and manganese.

[0043] The waste positive electrode can be recovered by separating the positive electrode from the waste lithium secondary battery. As described above, the waste positive electrode can include a positive electrode current collector (e.g., aluminum (Al)) and a positive electrode active material layer, and the positive electrode active material layer can include a conductive material, a binder, and the above positive electrode active material.

[0044] The conductive material can include, for example, a carbon-based material such as graphite, carbon black, graphene, carbon nanotubes, etc. The binder can include a resin material such as polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, etc.

[0045] In an exemplary embodiment, the recovered waste positive electrode can be pulverized to produce a positive electrode active material mixture. Thus, the positive electrode active material mixture can be made in powder form.

[0046] As described above, the positive active material mixture may include a powder of a lithium-transition metal oxide, such as an NCM-based lithium oxide powder (e.g., Li(NCM)O2). In this case, in the NCM-based lithium oxide powder, M1, M2, and M3 in Chemical Formula 1 may be Ni, Co, and Mn, respectively.

[0047] The term "positive electrode active material mixture" used in the present application may refer to a raw material that is subjected to a reduction reaction treatment as will be described below after the positive electrode current collector is substantially removed from the waste positive electrode. In one embodiment, the positive electrode active material mixture may include positive electrode active material particles, such as NCM-based lithium oxide. In one embodiment, the positive electrode active material mixture may partially include components derived from a binder or a conductive material. In one embodiment, the positive electrode active material mixture may be substantially composed of positive electrode active material particles.

[0048] In some embodiments, the average particle size (D 50 ) may be 5 μm to 100 μm. Within the above range, the lithium-transition metal oxide to be recycled, such as Li(NCM)O2, may be easily separated from the positive electrode current collector, the conductive material contained in the positive electrode active material mixture, and the binder.

[0049] In some embodiments, the positive electrode active material mixture may be heat treated before being introduced into the reduction reactor to be described below. Through the heat treatment, impurities such as conductive materials and binders contained in the spent positive electrode active material mixture may be removed or reduced, and the lithium-transition metal oxide may be introduced into the reduction reactor with high purity.

[0050] The temperature of the heat treatment may be, for example, about 100° C. to 500° C., preferably about 350° C. to 450° C. Within the above range, impurities may be substantially removed while preventing the lithium-transition metal oxide from being decomposed and damaged.

[0051] For example, in the process of S20 , the positive active material mixture may react in the reduction reactor 100 to form a primary precursor mixture 80 .

[0052] like Figure 1 As shown, the reduction reactor 100 may be divided into a reactor body 130, a lower reactor portion 110, and an upper reactor portion 150. The reactor body 130 may include a heating means such as a heater or may be integrated with a heating means such as a heater.

[0053] The positive active material mixture may be supplied into the reactor body 130 through the supply flow path 106a and the supply flow path 106b. The positive active material mixture may be dripped through the first supply flow path 106a connected to the upper reactor portion 150, or may be introduced through the second supply flow path 106b connected to the bottom of the reactor body 130. In one embodiment, the first supply flow path 106a and the second supply flow path 106b may be used together to supply the spent positive active material mixture.

[0054] For example, the support unit 120 may be disposed between the reactor body 130 and the lower reactor portion 110 so that the powder of the spent positive active material mixture may be placed. The support unit 120 may include a hole or an injection hole through which a reducing reaction gas and / or a carrier gas to be described below may pass.

[0055] The reducing reaction gas for converting the positive electrode active material mixture into the primary precursor can be supplied to the reactor body 130 through the reaction gas flow path 102 connected to the lower reactor part 110. In some embodiments, the reducing reaction gas may include hydrogen (H2). The reducing reaction gas may further include a carrier gas, such as nitrogen (N2), argon (Ar), etc.

[0056] The reducing reaction gas may be supplied from the bottom of the reduction reactor 100 to contact the cathode active material mixture, so that the cathode active material mixture may react with the reducing reaction gas to be converted into a primary precursor while moving to the upper reactor part 150 or residing in the reactor body 130 .

[0057] In some embodiments, a reducing reaction gas may be injected to form a fluidized bed in the reactor body 130. Therefore, the reduction reactor 100 may be a fluidized bed reactor. The cathode active material mixture and the reducing reaction gas may contact each other in the fluidized bed while repeatedly rising, staying, and falling, thereby increasing the reaction contact time and improving the dispersion of the particles. Therefore, a primary precursor mixture 80 having a uniform size may be obtained.

[0058] However, the present inventive concept is not necessarily limited to a fluidized bed reaction. For example, a fixed reaction in which a reducing reaction gas is supplied after preloading a cathode active material mixture in a batch reactor or a tubular reactor may be performed.

[0059] The reducing reaction gas may be supplied from the lower portion of the reduction reactor 100 to contact the positive active material mixture, so that the positive active material mixture may move to the upper reactor portion 150 while expanding the reaction area and may be converted into a primary precursor.

[0060] In some embodiments, the lithium-transition metal oxide can be reduced by a reducing reaction gas to produce a primary lithium precursor including, for example, lithium oxide (e.g., LiO2), lithium hydroxide (LiOH), etc., and a transition metal or transition metal oxide. For example, Ni, Co, NiO, CoO, and MnO can be produced together with lithium oxide by a reduction reaction.

[0061] For example, as the reduction process proceeds, the Li(NCM)O2 crystal structure may collapse and Li may be released from the crystal structure. NiO and CoO may be generated from the crystal structure, and as the reduction process continues, the Ni phase and the Co phase may be generated together.

[0062] Thus, a primary precursor mixture 80 including primary lithium precursor particles 60 and transition metal-containing particles 70 (eg, transition metal or transition metal oxide) may be formed. The primary lithium precursor particles 60 may include, for example, lithium hydroxide (LiOH), lithium oxide (LiO2) and / or lithium carbonate (LI2CO3).

[0063] The transition metal-containing particles 70 may include Ni, Co, NiO, CoO, and MnO as described above.

[0064] In an exemplary embodiment, the reduction degree of the transition metal of the primary precursor mixture 80 determined by X-ray diffraction analysis (XRD) and defined by Equation 1 may be in the range of 0.24 to 1.6.

[0065] [Equation 1]

[0066] Reduction degree of transition metal = (MeO phase fraction + lithium-transition metal oxide phase fraction) / (Me phase fraction)

[0067] In the above equation 1, Me includes Ni and Co. For example, the MeO phase may be the molar fraction of the NiO phase and the CoO phase in the primary precursor mixture produced by the reduction process. The Me phase may be the molar fraction of Ni and Co in the primary precursor mixture produced by the reduction process.

[0068] The lithium-transition metal oxide phase fraction in Equation 1 may represent, for example, the fraction of lithium-transition metal oxide that is not reacted or collapsed by the above-mentioned reduction process. The lithium-transition metal oxide may represent an NCM-based lithium oxide, and may be represented by the following Chemical Formula 1-1.

[0069] [Chemical formula 1-1]

[0070] Li x Ni a Co b Mn c O y

[0071] (In chemical formula 1-1, 0 <x≤1.1,2≤y≤2.02,0<a<1,0<b<1,0<c<1,0<a+b+c≤1)。

[0072] For the peaks obtained from the XRD analysis, the mole fractions can be obtained through crystal structure analysis by the Rietveld method.

[0073] If the reduction degree of the transition metal is less than 0.24, the transition metal may be over-reduced to generate a large amount of metal aggregates, thereby inhibiting the formation of a sufficient fluidized bed in the reactor body 130 and preventing the formation of primary lithium precursor particles 60 from adhering to the inner wall of the reactor body 130.

[0074] If the reduction degree of the transition metal exceeds 1.6, the collapse of the crystal structure of the lithium-transition metal compound may not be sufficiently induced. Therefore, the lithium precursor recovery rate may be reduced because lithium ions may not be sufficiently released.

[0075] The degree of reduction of the transition metal can be finely controlled using process conditions, such as the hydrogen concentration in the reducing reaction gas, the flow rate of the reducing reaction gas, the reaction temperature, the reduction reaction time, and the like.

[0076] In a preferred embodiment, the reduction degree of the transition metal defined by Equation 1 may be in the range of 0.24 to 1.0.

[0077] In one embodiment, the hydrogen concentration in the reducing reaction gas may be in the range of about 10 volume % to 40 volume % (vol %). As described above, the reducing reaction gas may be a mixed gas of hydrogen and a carrier gas, and the hydrogen concentration may be the volume % of hydrogen in the total volume of the mixed gas.

[0078] The temperature of the reduction reaction may be controlled within a range of about 400°C to 800°C, preferably within a range of about 400°C to 600°C, and more preferably within a range of about 400°C to 500°C.

[0079] The primary precursor mixture 80 obtained through the above-described dry reduction process may be collected for subsequent recycling process.

[0080] In one embodiment, the transition metal-containing particles 70 including nickel, cobalt, or manganese may be relatively heavier than the primary lithium precursor particles 60 , and thus the primary lithium precursor particles 60 may be discharged in advance through the outlet 160 a and the outlet 160 b to be collected.

[0081] In one embodiment, the primary lithium precursor particles 60 may be discharged through the first outlet 160a connected to the upper reactor portion 150. In this case, selective recovery of the primary lithium precursor particles 60 according to a weight gradient may be facilitated.

[0082] In one embodiment, the primary precursor mixture 80 including the primary lithium precursor particles 60 and the transition metal-containing particles 70 may be collected through the second outlet 160b connected to the reactor body 130. In this case, the primary precursor mixture 80 may be directly recovered from the fluidized bed forming area to increase yield.

[0083] In one embodiment, the primary precursor mixture 80 may be collected together through the first outlet 160a and the second outlet 160b.

[0084] The primary lithium precursor particles 60 collected through the outlet 160 may be recovered as a lithium precursor (eg, S30 process).

[0085] In some embodiments, the primary lithium precursor particles 60 may be washed with water. The primary lithium precursor particles in the form of lithium hydroxide (LiOH) may be substantially dissolved in water, separated from the transition metal precursor and previously recovered by a washing process. The lithium precursor consisting essentially of lithium hydroxide may be obtained by a crystallization process of dissolving lithium hydroxide in water, etc.

[0086] In one embodiment, primary lithium precursor particles in the form of lithium oxide and lithium carbonate may be substantially removed by a washing process. In one embodiment, primary lithium precursor particles in the form of lithium oxide and lithium carbonate may be at least partially converted to lithium hydroxide by a washing process.

[0087] In some embodiments, the primary lithium precursor particles 60 can react with a carbon-containing gas such as carbon monoxide (CO), carbon dioxide (CO2), etc. to obtain lithium carbonate (e.g., Li2CO3) as a lithium precursor. A crystalline lithium precursor can be obtained by reacting with a carbon-containing gas. For example, lithium carbonate can be collected by injecting a carbon-containing gas together during a washing process.

[0088] The temperature of the crystallization reaction using the carbon-containing gas may be in the range of, for example, about 60° C. to 150° C. Within the above temperature range, lithium carbonate with high reliability may be produced without damaging the crystal structure.

[0089] As described above, according to exemplary embodiments, a lithium precursor may be recovered from a spent positive electrode through a continuous dry process.

[0090] In comparative examples, wet processes such as leaching with a strong acid solution can be used to recover lithium or transition metals from waste secondary batteries. However, the selective separation of lithium is limited in wet processes. In addition, a washing process is required to remove solution residues, and byproducts such as hydrates may increase due to contact with the solution.

[0091] However, according to an embodiment of the present invention, the lithium precursor can be collected through a dry reduction reaction without using a solution, so that the yield can be improved and by-products can be reduced, and an environmentally friendly process design without wastewater treatment can be implemented.

[0092] Furthermore, the degree of reduction of transition metals can be controlled to facilitate the extraction of lithium, and lithium precursors can be recovered with high purity and high yield while preventing metal aggregation.

[0093] In some embodiments, a transition metal precursor may be obtained from the collected transition metal-containing particles 70 (eg, S40 process).

[0094] For example, the primary lithium precursor particles 60 may be collected through the outlet 160a and the outlet 160b, and then the transition metal-containing particles 70 may be recovered. Thereafter, the transition metal-containing particles 70 may be treated with an acid solution to form a precursor in the form of an acid salt of each transition metal.

[0095] In one embodiment, the primary lithium precursor particles 60 and the transition metal-containing particles 70 may be collected together and a washing process may be performed. In this case, the primary lithium precursor particles 60 may be converted and dissolved into a lithium precursor such as lithium hydroxide, and the transition metal-containing particles 70 may be precipitated. The precipitated transition metal-containing particles 70 may be collected again and treated with an acid solution.

[0096] In one embodiment, sulfuric acid can be used as the acid solution. In this case, NiSO4, MnSO4 and CoSO4 can each be recovered as a transition metal precursor.

[0097] As described above, the lithium precursor can be collected by a dry process, and then the transition metal precursor can be selectively extracted using an acid solution, so that the purity and selectivity of each metal precursor can be improved, and the load of the wet process can be reduced, and the amount of wastewater and by-products can also be reduced.

[0098] Hereinafter, preferred embodiments are proposed to more specifically describe the present invention. However, the following examples are only used to illustrate the present invention, and those skilled in the relevant art will clearly understand that various changes and modifications can be made within the scope and spirit of the present invention. Such changes and modifications are appropriately included in the appended claims.

[0099] Example 1

[0100] 1 kg of positive electrode material separated from waste lithium secondary batteries was heat treated at 450 ° C for 1 hour. The heat-treated positive electrode material was cut into small pieces and ground to obtain a Li-Ni-Co-Mn oxide positive electrode active material sample. 20 g of the positive electrode active material sample was placed in a fluidized bed reactor, and a mixed gas of 20% by volume hydrogen / 80% by volume nitrogen was injected from the bottom of the reactor at a flow rate of 400 mL / min for 4 hours while the internal temperature of the reactor was maintained at 455 ° C to obtain a primary precursor mixture.

[0101] After the reduction degree of the transition metal was determined using the XRD analysis of the obtained primary precursor mixture, the primary precursor mixture and water (19 times; based on weight) were added and stirred. The concentration of lithium dissolved in water was analyzed to measure the recovery rate of lithium based on the weight ratio of lithium dissolved in water relative to the weight of lithium in the initial positive active material sample.

[0102] Example 2

[0103] The same procedure as in Example 1 was carried out except that the reaction time was changed to 3 hours.

[0104] Example 3

[0105] 2 g of the same positive electrode active material sample as in Example 1 was placed in a tubular reactor. The internal temperature of the reactor was maintained at 450° C., and a mixed gas of 40% by volume hydrogen / 60% by volume nitrogen was injected at a flow rate of 50 mL / min for 3 hours to obtain a primary precursor mixture. Thereafter, the reduction degree of the transition metal and the recovery rate of lithium were determined by the same method as in Example 1.

[0106] Example 4

[0107] The same procedure as in Example 3 was performed except that the reaction temperature was adjusted to 430° C. and a mixed gas of 20 vol % hydrogen / 80 vol % nitrogen was injected at a flow rate of 50 mL / min for 5 hours.

[0108] Example 5

[0109] The same process as in Example 2 was performed except that a mixed gas of 15 vol % hydrogen / 80 vol % nitrogen was used.

[0110] Comparative Example 1

[0111] The same procedure as in Example 1 was carried out except that the reaction temperature was changed to 470° C. and the reaction time was changed to 3 hours.

[0112] Comparative Example 2

[0113] The same procedure as in Example 3 was performed except that the reaction temperature was maintained at 450° C. and a mixed gas of 12.5 vol % hydrogen / 87.5 vol % nitrogen was injected at a flow rate of 50 mL / min for 5 hours.

[0114] Comparative Example 3

[0115] The same procedure as in Example 3 was performed except that the reaction temperature was maintained at 465° C. and a mixed gas of 30 vol % hydrogen / 70 vol % nitrogen was injected at a flow rate of 30 mL / min for 1.5 hours.

[0116] Comparative Example 4

[0117] The same procedure as in Comparative Example 3 was performed except that the mixed gas injection time was changed to 1 hour.

[0118] In each of the examples and comparative examples, the degree of reduction of the transition metal according to equation 1 was determined by Rietveld refinement analysis of the XRD peaks of the primary precursor mixture, and the recovery rate of lithium was determined after mixing with water. The evaluation results are shown in Table 1 below.

[0119] [Table 1]

[0120]

[0121] Referring to Table 1, when the reduction degree of the transition metal was adjusted within the range according to the above-described embodiment of the present invention, a significantly higher lithium recovery rate was obtained, compared with the lithium recovery rate of the comparative example.

Claims

1. A method for recovering active metals from a lithium secondary battery, comprising: preparing a positive electrode active material mixture containing lithium-transition metal oxide from a waste positive electrode of a lithium secondary battery; reacting the cathode active material mixture with a reducing reaction gas to form a primary precursor mixture having a degree of reduction of the transition metal defined by Equation 1 in a range of 0.24 to 0.77; and recovering a lithium precursor from the primary precursor mixture, Wherein, forming the primary precursor mixture comprises reacting the cathode active material mixture with the reducing reaction gas in a fluidized bed reactor: [Equation 1] Reduction degree of transition metal = (MeO phase fraction + lithium-transition metal oxide phase fraction) / (Me phase fraction) In Equation 1, Me includes Ni and Co, and the MeO phase fraction, the lithium-transition metal oxide phase fraction, and the Me phase fraction are determined by performing Rietveld crystal structure analysis on X-ray diffraction (XRD) analysis peaks of the primary precursor mixture.

2. The method for recovering active metals from lithium secondary batteries according to claim 1, wherein: The lithium-transition metal oxide is represented by Chemical Formula 1: [Chemical formula 1] Li x Ni a Co b Mr c O y In chemical formula 1, 0 <x≤1.1,2≤y≤2.02,0<a<1,0<b<1,0<c<1,0<a+b+c≤1。 3. The method for recovering active metals from lithium secondary batteries according to claim 1, wherein: The reducing reaction gas includes hydrogen and a carrier gas, and a concentration of hydrogen in the reducing reaction gas is in a range of 10 volume % to 40 volume %.

4. The method for recovering active metals from lithium secondary batteries according to claim 1, wherein: The reaction temperature with the reducing reaction gas is in the range of 400°C to 600°C.

5. The method for recovering active metals from lithium secondary batteries according to claim 1, wherein: The primary precursor mixture includes primary lithium precursor particles and transition metal-containing particles, and The transition metal-containing particles include Ni, Co, NiO, CoO and MnO.

6. The method for recovering active metals from lithium secondary batteries according to claim 5, wherein: The primary lithium precursor particles include at least one of lithium hydroxide, lithium oxide and lithium carbonate.

7. The method for recovering active metals from lithium secondary batteries according to claim 5, wherein: The recovering of the lithium precursor includes washing the primary lithium precursor particles with water. 8 . The method for recovering active metals of lithium secondary batteries according to claim 5 , further comprising selectively treating the transition metal-containing particles with an acid solution to recover the transition metal precursor in the form of an acid salt.

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