Method for producing alloy by reducing cathode materials or anode materials of waste lithium batteries with arc plasma in hydrogen atmosphere

Abstract

The present invention relates to a method for producing an alloy by reducing cathode materials or anode materials of waste lithium batteries with arc plasma in a hydrogen atmosphere. More specifically, the present invention relates to a method for producing an alloy by reducing cathode materials or anode materials of waste lithium batteries with arc plasma in a hydrogen atmosphere, wherein high-temperature arc plasma generated in the hydrogen atmosphere is used to produce a reduced alloy from LiNi0.8Co0.1Mn0.1O2 (NCM811; Lithium Nickel Cobalt Manganese Oxide), LiCoO2 (LCO; Lithium Cobalt Oxide), LiFePO4 (LFP; Lithium Iron Phosphate), Li4Ti5O12 (LTO; Lithium Titanate Oxide), etc. contained in cathode materials of waste lithium batteries.

Description

A method for manufacturing an alloy by reducing spent lithium battery cathode or anode material with arc plasma in a hydrogen atmosphere.

[0001] The present invention relates to a method for manufacturing an alloy by reducing a spent lithium battery cathode or anode material in an arc plasma in a hydrogen atmosphere, and more specifically, to a method for using high-temperature arc plasma generated in a hydrogen atmosphere to reduce LiNi contained in the spent lithium battery cathode or anode material. 0.8 Co 0.1 Mn 0.1 O2(NCM811; Lithium Nickel Cobalt Manganese Oxide), LiCoO2(LCO; Lithium Cobalt Oxide), LiFePO4(LFP; Lithium Iron Phosphate), Li4Ti5O 12 The present invention relates to a method for producing an alloy by reducing a spent lithium battery cathode or anode material in an arc plasma in a hydrogen atmosphere, characterized by producing an alloy reduced from (LTO; Lithium Titanate Oxide), etc.

[0002] Currently, as interest in eco-friendly energy gains global attention, the volume of waste batteries is rapidly increasing alongside the rise in the use of secondary batteries. According to statistical surveys, electric vehicle sales in 2023 reached 14 million units, a sixfold increase compared to 2018; consequently, the number of scrapped vehicles is projected to reach 4.11 million in 2030 and 42.77 million in 2040.

[0003] Next-generation waste battery recycling technology can alleviate environmental issues and raw material supply shortages, and reduce dependence on overseas imports of cathode materials, which are currently landfilled only in specific countries. Global companies and research institutions are devoting significant effort to developing waste battery recycling technologies, and the battery recycling market is projected to grow to approximately 200 trillion won by 2040.

[0004] In the case of lithium batteries utilized as cathode materials for conventional lithium batteries, High Ni cathode materials are mainly used in Korea, and LiNi 0.6 Co 0.2 Mn 0.2 O2(NCM622), LiNi 0.7 Co 0.2 Mn 0.1 O2(NCM721), LiNi 0.8 Co 0.1 Mn 0.1 Cathode materials such as O2 (NCM811) are primarily used. In China, which has a high volume of battery production, inexpensive LiFePO4 (LFP) is the main cathode material. Both NCM batteries and LFP materials contain valuable metals such as Ni and Co, as well as metals such as Fe, which are widely used in everyday life. Furthermore, metals like Ni, Co, and Fe have numerous applications, to the extent that they can be used as superalloys such as Super Invar. It is expected that recycling and utilizing the metals present in these battery powders will create a significant impact.

[0005] The prior patents related to waste lithium battery recycling technology currently in use are as follows.

[0006] Methods include a method for crushing and dry heat-treating cell-unit batteries and separating them through particle size separation and magnetic separation (Patent Application No. 10-2023-0038360), a method for recovering precursors such as Ni, Co, and Mn using strong sulfates (Patent Application No. 10-2021-0122698), a method for controlling the alloy size of Ni using sulfuric acid and a complex heat treatment process (Patent Application No. 10-2022-0130603), a method for extracting Co using a complex process in an acidic atmosphere utilizing a mixed solvent (Patent Application No. 10-2022-0029821), a method for obtaining lithium hydroxide through a relatively complex process (Patent Application No. 10-2020-0166203), and a method for recovering cathode material particles using an oxygen atmosphere and sodium hydroxide (Patent Application No. 10-2021-0120343).

[0007] Conventional battery recycling methods, such as the technology described above, apply a process in which waste lithium batteries are crushed and ground into black powder and recycled using wet and dry methods. However, wet and dry methods have problems in that the process is complex, time-consuming, and has a low yield, and is not environmentally friendly because it generates toxic gases and involves repeated oxidation and reduction processes.

[0008] These differences can be summarized as follows.

[0009] Prior Art No. Differences from the Present Invention Patent Application No. 10-2023-0038360 Complex process of crushing, grinding, freezing, and heat treatment Patent Application No. 10-2022-0130603 Use of sulfuric acid and complex heat treatment process Patent Application No. 10-2022-0029821 Method for extracting Co using a complex process in an acidic atmosphere utilizing a mixed solvent Patent Application No. 10-2021-0122698 Not true recycling through eco-friendly reduction using very strong sulfates Patent Application No. 10-2021-0120343 Recovery of cathode material particles through a method including an oxygen atmosphere and sodium hydroxide Patent Application No. 10-2020-0166203 Obtaining lithium hydroxide through a complex process

[0010] The present invention presents a Hydrogen Plasma Reduction (HPR) method that extracts Ni, Co, and Fe from waste batteries very quickly and simply by utilizing hydrogen and a plasma arc, deviating from conventional methods applied in the prior art that are harmful to the environment, such as strong acids and strong bases, and are complex and time-consuming.

[0011] However, there exists a prior patent that applies a technology for reducing and separating waste metals using conventional plasma reduction technology, which differs from the present invention as follows.

[0012] The invention of Patent Application No. 10-2019-0128689 is technically different from the present invention in that it utilizes plasma to process waste aluminum (metal) and extracts high-purity aluminum without using hydrogen, and in the case of waste aluminum, aluminum metal is extracted from metal rather than ceramic.

[0013] Furthermore, the inventions of Patent Applications No. 10-2016-0025143 and No. 10-2014-0047960 utilized metallic titanium in the technology for reducing impurities in titanium by generating arc plasma in a hydrogen atmosphere, and in the case of recovering copper from copper-containing waste, they utilized hydrogen generated from LPG gas in addition to recovering metal from metal, which differs from the present invention in that hydrogen is directly added.

[0014] In addition, the invention of Patent Application No. 10-1998-0058249 presents a technology for recovering valuable metals from industrial waste using plasma; however, this invention also does not use hydrogen and differs in that waste batteries are compositionally different from industrial waste.

[0015] Prior Art No. Differences from the present invention Patent Application No. 10-2019-0128689: Extraction of metal from metal. No hydrogen used when utilizing plasma. Patent Application No. 10-2016-0025143: Extraction of metal from metal. Patent Application No. 10-2014-0047960: Extraction of metal from metal. LPG gas used when utilizing plasma. Patent Application No. 10-1998-0058249: Industrial waste and waste batteries have different compositions; no hydrogen used when utilizing plasma.

[0016] Super Invar alloy is a representative low thermal expansion alloy, and the coefficient of thermal expansion (CTE) of the 64% Fe-36% Ni Invar36 alloy is 2×10⁻⁶ -6 K -1 The super Invar alloy, which is smaller and composed of Fe-32%Ni-5%Co, is 1×10⁻⁶ -7 K -1It has a coefficient of thermal expansion that is nearly zero. Due to this low thermal expansion characteristic, super Invar alloys have been used in precision processes and precision analysis equipment, and furthermore, they are materials with very high added value in future industries such as LNG vessels, semiconductors, displays, and the advanced space industry. Therefore, the method of designing high-value-added super Invar alloys from waste lithium battery powder through waste lithium battery upcycling technology can be considered a unique and excellent technology in terms of industrial applications, economic utility, and environmental contribution.

[0017]

[0018] Meanwhile, high-entropy alloys are alloys composed of at least four major elements in equal or nearly similar compositional ratios, and they possess excellent mechanical and thermal properties. As the number of constituent elements increases, the configurational entropy (ΔS) increases, and the Gibbs free energy (ΔG) decreases. Furthermore, they are gaining attention in the metals field because properties such as mechanical, thermal, magnetic, and corrosion resistance can be controlled depending on which elements are added and in what quantities.

[0019] FeCoNiCu high-entropy alloys are alloys that possess soft magnetic properties and excellent mechanical properties, such as high strength and ductility. Various combinations of high-entropy alloys, including FeCoNiCu, FeCoNiMnAl, and FeCoNiCuAl, can be derived from waste battery materials. Due to their soft magnetic properties and excellent mechanical characteristics, such as high ductility and strength even at cryogenic temperatures, these high-entropy alloys are materials with very high industrial value, suitable for applications such as ships and pipes for polar regions, cryogenic liquid gas transport containers, electric generators, electric motors, electromagnets, and magnetic shielding materials.

[0020]

[0021] Meanwhile, Ti-Al alloys are lightweight, high-strength, corrosion-resistant, and high-heat-resistant alloys utilized as materials for aircraft engine turbine blades and high-temperature lightweight materials for aerospace applications, making them materials with very high future value. The present invention aims to design Ti-Al alloys using a hydrogen atmosphere arc plasma by recovering and utilizing valuable metals from the negative electrode material, electrode, and current collector present in spent lithium batteries.

[0022] Ti-Al alloys are alloys composed of the γ phase (TiAl phase) or the γ phase and α2 phase (Ti3Al phase). Since the main constituent elements are Ti and Al, they are inherently lightweight, and their specific gravity is only about half that of nickel superalloys, making them excellent for lightweighting aircraft materials, reducing CO2 emissions, and conserving energy resources. In addition, they possess excellent high-temperature properties, making them highly valuable materials for the aerospace industry. This invention offers significant economic and industrial advantages by going beyond simple recycling of waste batteries and upcycling them into Ti-Al alloys in a fast and very simple manner.

[0023] The present invention, aimed at solving the aforementioned problems, provides a method for producing an alloy by reducing a spent lithium battery cathode material in an arc plasma environment in a hydrogen atmosphere, which enables the rapid and efficient recovery of valuable metals contained in the spent lithium battery cathode material and the simultaneous production of a super Invar alloy.

[0024] In addition, the present invention aims to provide a method for producing an alloy by reducing a spent lithium battery cathode material in an arc plasma environment in a hydrogen atmosphere, which enables the rapid and efficient recovery of valuable metals contained in the spent lithium battery cathode material and the production of a high-entropy alloy.

[0025] Furthermore, the present invention aims to provide a method for manufacturing an alloy by reducing a spent lithium battery negative electrode material in an arc plasma environment in a hydrogen atmosphere, which enables the rapid and efficient recovery of valuable metals contained in the spent lithium battery negative electrode material by reducing the negative electrode material in an arc plasma environment in a hydrogen atmosphere, and at the same time allows for the alloy design from the spent lithium battery negative electrode material to be performed in a single step using a very simple and rapid hydrogen atmosphere arc plasma process.

[0026] In addition, the invention aims to provide a method for producing alloys by reducing spent lithium battery cathode or anode materials in an arc plasma in a hydrogen atmosphere, which enables the direct production of super Invar alloys, high-entropy alloys, TI-Al alloys, etc., with excellent properties while reprocessing oxidized cathode or anode materials of NCM, LCO, and LFP batteries in an environmentally friendly manner.

[0027] A method for manufacturing a super Invar alloy from a cathode material of a spent lithium battery using an arc plasma comprises: a first step of preparing a cathode material contained in the spent lithium battery; a second step of exposing the cathode material to a plasma arc to induce a reduction reaction; a third step of separating the plasma-reduced super Invar alloy from impurity particles; and a fourth step of mixing calcium carbonate with the separated super Invar alloy and exposing the super Invar alloy mixed with calcium carbonate to a plasma arc to induce a reduction reaction.

[0028] In the first step above, the cathode material is composed of a mixture of NCM and LFP, wherein the NCM and LFP are mixed in a ratio of 1:2 to 1:10.

[0029] The first step above is characterized by grinding the cathode material, which is a mixture of the NCM and the LFP, into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

[0030] The second step above is characterized by introducing the oxidized anode material into a hydrogen plasma reduction device (100) and reducing the anode material in a hydrogen atmosphere.

[0031] The above hydrogen plasma reduction device (100) comprises: a chamber (102) having a space formed inside; a cathode (104) installed on the inner upper surface of the chamber (102); an anode (106) installed on the inner bottom surface of the chamber (102); a power supply unit connected to the cathode (104) and the anode (106) to supply power; a supply tank (108) for supplying gas for plasma generation; and a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

[0032] The above supply tank (108) is characterized by storing hydrogen and argon gas and supplying them into the interior of the chamber (102).

[0033] The above supply tank (108) is characterized by supplying gas containing 90% argon and 10% hydrogen.

[0034] The above third step is characterized by separating the Super Invar alloy by bringing a magnetic material having magnetic force close to the anode material after reduction.

[0035] It further includes a fifth step of washing and post-processing the separated superinvar alloy.

[0036] The above super Invar alloy comprises iron, nickel, and cobalt, wherein the iron has a composition ratio of 59 at% to 65 at%, the nickel has a composition ratio of 30 at% to 36 at%, and the cobalt has a composition ratio of 4 at% to 7 at%.

[0037] According to another embodiment, the present invention comprises a method for manufacturing a super Invar alloy from a cathode material of a spent lithium battery using an arc plasma, the method comprising: a first step of preparing a cathode material contained in the spent lithium battery; a second step of exposing the cathode material to a plasma arc to induce a reduction reaction; and a third step of separating the plasma-reduced super Invar alloy from impurity particles.

[0038] In the first step above, the cathode material is composed of a mixture of NCM and LFP, wherein the NCM and LFP are mixed in a ratio of 1:2 to 1:10, and calcium carbonate (CaCO3) is additionally mixed into the mixture of NCM and LFP.

[0039] The first step above is characterized by grinding the cathode material, which is composed of a mixture of the NCM, the LFP, and the calcium carbonate, into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

[0040] According to another embodiment, the present invention comprises a method for manufacturing a high-entropy alloy from a cathode material of a spent lithium battery using an arc plasma, the method comprising: a first step of preparing a cathode material pellet using a cathode material contained in the spent lithium battery; a second step of preparing a copper pellet using a negative electrode current collector contained in the spent lithium battery; a third step of exposing a mixture of the cathode material pellet and the copper pellet to a plasma arc to induce a reduction reaction; and a fourth step of separating the plasma-reduced high-entropy alloy from impurity particles.

[0041] In the first step above, the cathode material pellet is composed of a mixture of NCM, LCO, and LFP, wherein the NCM, LCO, and LFP are mixed in a weight ratio of (5.5~8):(4~6):(1.5~3.5).

[0042] The first step above is characterized by grinding the cathode material, which is composed of a mixture of the NCM, the LCO, and the LFP, into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

[0043] In the second step above, the copper pellet is characterized by using a negative electrode current collector in the form of copper foil contained in the waste lithium battery by pelletizing it.

[0044] The copper contained in the above NCM, above LCO, above LFP, and above copper pellets is mixed in a weight ratio of (5.5~8):(4~6):(1.5~3.5):(4.5~7).

[0045] The above third step is characterized by introducing the anode material mixed with the anode material pellet and the copper pellet into a hydrogen plasma reduction device (100) and reducing the anode material in a hydrogen atmosphere.

[0046] The above hydrogen plasma reduction device (100) comprises: a chamber (102) having a space formed inside; a cathode (104) installed on the inner upper surface of the chamber (102); an anode (106) installed on the inner bottom surface of the chamber (102); a power supply unit connected to the cathode (104) and the anode (106) to supply power; a supply tank (108) for supplying gas for plasma generation; and a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

[0047] The above supply tank (108) is characterized by storing hydrogen and argon gas and supplying them into the interior of the chamber (102).

[0048] The above supply tank (108) is characterized by supplying gas containing 90% argon and 10% hydrogen.

[0049] It further includes a fifth step of washing and post-treating the separated high-entropy alloy.

[0050] The high-entropy alloy comprises iron, cobalt, nickel, and copper, wherein the iron has a composition ratio of 25 at% to 28 at%, the cobalt has a composition ratio of 22 at% to 24 at%, the nickel has a composition ratio of 23 at% to 25 at%, and the copper has a composition ratio of 25 at% to 27 at%.

[0051] According to another embodiment, the present invention comprises a method for manufacturing a Ti-Al alloy from a negative electrode material of a spent lithium battery using an arc plasma, the method comprising: a first step of preparing a negative electrode pellet using a negative electrode material contained in the spent lithium battery; a second step of preparing an aluminum pellet using an aluminum current collector contained in the spent lithium battery; a third step of exposing a mixture of the negative electrode pellet and the aluminum pellet to a plasma arc to induce a reduction reaction; and a fourth step of separating the plasma-reduced Ti-Al alloy from impurity particles.

[0052] In the first step above, the cathode material pellet is composed of LTO (Lithium Titanate Oxide) cathode material, and the LTO and aluminum are mixed in a weight ratio of LTO:Al = 1:2 to 1:5.

[0053] The first step above is characterized by grinding the cathode material composed of the LTO into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

[0054] In the second step above, the aluminum pellets are characterized by using aluminum foil-shaped current collectors contained in the waste lithium battery by pelletizing them.

[0055] The above third step is characterized by introducing the cathode material mixed with the above cathode material pellet and the above aluminum pellet into a hydrogen plasma reduction device (100) and reducing the cathode material in a hydrogen atmosphere.

[0056] The above hydrogen plasma reduction device (100) comprises: a chamber (102) having a space formed inside; a cathode (104) installed on the inner upper surface of the chamber (102); an anode (106) installed on the inner bottom surface of the chamber (102); a power supply unit connected to the cathode (104) and the anode (106) to supply power; a supply tank (108) for supplying gas for plasma generation; and a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

[0057] The above supply tank (108) is characterized by storing hydrogen and argon gas and supplying them into the interior of the chamber (102).

[0058] The above supply tank (108) is characterized by supplying gas containing 90% argon and 10% hydrogen.

[0059] It further includes a fifth step of washing and post-treating the separated Ti-Al alloy.

[0060] The γ-TiAl alloy, manufactured by mixing the above LTO and the above aluminum in a weight ratio of LTO:Al = 1:3.4, is characterized by having a composition of Ti and Al of 39.8 at% and 56.2 at%, respectively.

[0061] The γ+α2-phase TiAl alloy, manufactured by mixing the above LTO and the above aluminum in a weight ratio of LTO:Al = 1:3.2, is characterized by having an Al composition of 44 at%.

[0062] According to the present invention, through a process of plasma reduction of spent lithium battery cathode materials, it is possible to recover valuable metals and simultaneously design a Super Invar alloy having desired characteristics from the spent battery cathode materials. In particular, since a Super Invar alloy, which is a superalloy, can be obtained directly through this process, there is an effect of obtaining high-value-added metals from spent lithium battery cathode materials.

[0063] Furthermore, according to the present invention, through a process of plasma reduction of spent lithium battery cathode materials, it is possible not only to recover valuable metals but also to design high-entropy alloys with desired characteristics from the spent battery cathode materials in a single step. In particular, since high-entropy alloys with excellent mechanical and thermal properties can be obtained directly through this process, there is an effect of obtaining high-value-added metals from spent lithium battery cathode materials.

[0064] In addition, according to the present invention, valuable metal alloys within the waste lithium battery negative electrode material can be easily and simply designed by utilizing a hydrogen atmosphere arc plasma, and there is an effect of enabling not only the acquisition of pure metal but also the rapid and convenient design of alloys from the waste battery negative electrode material in a single step.

[0065] In addition, since the Ti-Al alloy can be obtained directly through the process of the present invention, there is an effect of obtaining high-value-added metals from waste lithium battery negative electrode materials and current collector materials.

[0066] In addition, by utilizing a plasma reduction process in a hydrogen atmosphere, the reduction efficiency is increased and the process speed is accelerated compared to the method using conventional Ar gas. Furthermore, the rapid reaction speed enables the production of super Invar alloys, high-entropy alloys, and Ti-Al alloys.

[0067] In addition, by utilizing a hydrogen atmosphere plasma, high-value alloys can be produced more efficiently through a rapid process compared to reduction methods using conventional inert gases; furthermore, if the negative electrode material within spent lithium batteries is properly mixed, it offers the effect of easily designing the desired alloy.

[0068] FIG. 1 is a flowchart showing the process of a method for manufacturing a superinvar alloy according to a first embodiment of the present invention.

[0069] FIG. 2 is a flowchart showing the process of a method for manufacturing a superinvar alloy according to a second embodiment of the present invention.

[0070] FIG. 3 is a conceptual diagram showing a reaction process carrying out the process illustrated in FIG. 1 and FIG. 2.

[0071] Figure 4 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0072] Figure 5 shows the composition ratio of Super Invar alloy according to the mixing ratio of NCM and LFP.

[0073] Figure 6 shows an SEM image and EDS analysis results of the super-Invar alloy produced by the present invention.

[0074] FIG. 7 is an atomic tomography image of a super-Invar alloy produced by the present invention.

[0075] FIG. 8 is an SEM image and an EBSD image of a super-Invar alloy produced by the present invention.

[0076] FIG. 9 is an SEM image of a superinvar alloy manufactured by the manufacturing method according to the first embodiment.

[0077] FIG. 10 is an SEM image of a super-invar alloy manufactured by the manufacturing method according to the second embodiment.

[0078] FIG. 11 is a flowchart showing the process of a method for manufacturing a high-entropy alloy according to a third embodiment of the present invention.

[0079] FIG. 12 is a conceptual diagram showing a reaction process carrying out the process illustrated in FIG. 11.

[0080] Figure 13 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0081] Figure 14 shows an SEM image and EDS analysis results of a high-entropy alloy produced by the present invention.

[0082] Figure 15 shows the XRD analysis results of the high-entropy alloy produced by the present invention.

[0083] FIG. 16 is an SEM image and an EBSD image of a high-entropy alloy produced by the present invention.

[0084] FIG. 17 is a flowchart showing the process of a method for manufacturing a Ti-Al alloy according to a fourth embodiment of the present invention.

[0085] FIG. 18 is a conceptual diagram showing a reaction process carrying out the process illustrated in FIG. 17.

[0086] Fig. 19 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0087] Figure 20 shows an SEM image and EDS analysis results of a Ti-Al alloy produced by the present invention.

[0088] FIG. 21 is an SEM image and an EBSD image of a Ti-Al alloy produced by the present invention.

[0089] Hereinafter, with reference to the drawings, a "method for manufacturing an alloy by arc plasma reduction of a spent lithium battery positive or negative electrode material in a hydrogen atmosphere" according to an embodiment of the present invention will be described.

[0090]

[0091] A method for manufacturing super Invar alloy by arc plasma reduction of spent lithium battery cathode material in a hydrogen atmosphere

[0092]

[0093] This embodiment relates to a method for manufacturing a super Invar alloy by arc plasma reduction of spent lithium battery cathode material in a hydrogen atmosphere, wherein the LiNi contained in the spent lithium battery cathode material is reduced using high-temperature arc plasma generated in a hydrogen atmosphere. 0.8 Co 0.1 Mn 0.1 The method is characterized by producing a super-invar alloy reduced from O2 (NCM811; Lithium Nickel Cobalt Manganese Oxide), LiCoO2 (LCO; Lithium Cobalt Oxide), LiFePO4 (LFP; Lithium Iron Phosphate), etc.

[0094]

[0095] FIG. 1 is a flowchart showing the process of a method for manufacturing a super Invar alloy according to a first embodiment of the present invention, FIG. 2 is a flowchart showing the process of a method for manufacturing a super Invar alloy according to a second embodiment of the present invention, FIG. 3 is a conceptual diagram showing the reaction process carrying out the process shown in FIG. 1 and FIG. 2, and FIG. 4 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0096] To carry out the method for manufacturing the super Invar alloy of the present invention, a four-step process as illustrated in FIG. 1 or FIG. 2 is performed. FIG. 1 and FIG. 2 illustrate the present invention according to a first embodiment and the present invention according to a second embodiment, respectively, and the two embodiments are described in order.

[0097]

[0098] First embodiment

[0099]

[0100] First, as a first step, a cathode material contained in a waste lithium battery is prepared (S102). In the present invention, a super Invar alloy was manufactured using NCM and LFP cathode materials, but other cathode materials may be used. NCM and LFP can be mixed in different ratios, but it is preferable to mix them in a ratio of 1:2 to 1:10, and it was found that the composition ratio of the super Invar alloy produced when mixed in this ratio is the best.

[0101] The entire assembly, including the aluminum anode and the anode active material coated thereon, is separated from the spent lithium battery. When separating the anode material from the spent lithium battery, it is preferable to separate the anode material itself, excluding the negative electrode and separator contained within the battery cell. Since various methods can be applied to the technology for separating the anode material from the spent lithium battery, the present invention does not specifically limit the separation method.

[0102] The separated cathode material may contain a binder.

[0103] It is preferable to grind the separated cathode material into a powder form, and to grind it appropriately to a size suitable for introduction into a plasma chamber.

[0104] It is desirable to shape the crushed cathode material powder into a form optimized for the plasma reduction reaction. In the case of cathode material processed into powder form, it may be fed directly without processing, but it is preferable to pelletize the cathode material using a mold with a diameter of approximately 10 mm to 20 mm and feed it into the reduction chamber. Most preferably, pelletization can be carried out by compressing approximately 200 mg or more of cathode material to a pressure of 600 MPa or more using a mold with a diameter of 13 mm.

[0105] As the next step, the cathode material pellet is exposed to a plasma arc in a hydrogen atmosphere to induce a reduction reaction. (S104)

[0106] The initial state cathode material powder pelletized in the previous step is fed into a hydrogen plasma reduction device (100) to remove oxygen through a reduction reaction.

[0107] A hydrogen plasma reduction device (100) has a cathode (104) and an anode (106) installed inside a chamber (102), and a supply tank (108) for injecting gas for plasma generation may be provided on the outside. A gas pipe connected to the supply tank (108) is connected to a gas inlet (110) formed on one side of the chamber (102), and hydrogen and argon gases supplied from the supply tank (108) flow into the chamber (102) through the gas inlet (110).

[0108] A pressure gauge (112) and a thermometer (114) for measuring internal pressure and temperature, respectively, may be installed in the chamber (102).

[0109] Typically, the cathode (104) can be installed on the upper inner surface of the chamber (102) and extend vertically through the upper surface. The anode (106) is installed on the lower inner surface of the chamber (102), and the anode material (10) before reduction can be placed on the anode (106).

[0110] A power supply unit (not shown in the drawing) is connected to the cathode (104) and the anode (106), and power is supplied from the power supply unit to generate plasma between the cathode (104) and the anode (106).

[0111] When power is supplied to the cathode (104) and the anode (106) while supplying a plasma gas, such as argon gas, through the gas inlet (110), an arc is generated at the electrical contact, changing the argon gas into a plasma state. The heat generated from the plasma melts the anode material (10) placed on the anode (106) before reduction, and the hydrogen supplied along with the argon gas causes a reduction reaction. The hydrogen combines with the oxygen bonded to the iron (Fe) and is discharged, leaving the anode material after reduction. The super-invar alloy remains as a metallic element inside the anode material after reduction.

[0112] In the present invention, after placing the anode material (10) inside a Cu water-cooled chamber (maintained at 20°C), an arc plasma is generated in an argon and hydrogen mixed gas atmosphere while supplying a gas containing 90% argon and 10% hydrogen to reduce the oxide anode material at a very high temperature.

[0113] It is preferable to set the pressure inside the chamber (102) to be in the range of -0.8 bar to -0.4 bar during the reduction reaction. It is also preferable to set the distance between the anode material specimen to be reduced and the plasma node to be about 1 cm. Furthermore, it is preferable to set the time for generating a plasma arc to cause the reduction reaction to occur to be 2 to 10 seconds.

[0114] In order to obtain a sufficient amount of super-invar alloy from the input cathode material, it is desirable to repeat the above plasma reduction reaction about 2 to 6 times while setting the pressure, time, and the distance between the cathode material specimen and the plasma node to be the same.

[0115] As the next step, the super Invar alloy produced through the plasma reduction reaction, the current collector, and impurity particles are separated. (S106)

[0116] After the plasma reduction reaction is completed, the super Invar alloy contained in the reduced anode material extracted from the chamber (102) has magnetism. Using this magnetism, the super Invar alloy composed of metals such as nickel, cobalt, and iron can be separated. In the present invention, a magnetic material such as a neodymium magnet having a magnetic force of 0.7 T or more is used, and the magnetic material is brought close to the reduced anode material to separate it. Since the aluminum current collector contained in the anode material (10) before reduction is a paramagnetic material, it does not adhere to the magnetic material and can be separated from the super Invar alloy.

[0117] Figure 5 shows the composition ratio of the super Invar alloy according to the mixing ratio of NCM and LFP, Figure 6 shows the SEM image and EDS analysis results of the super Invar alloy produced by the present invention, Figure 7 shows the atomic tomography image of the super Invar alloy produced by the present invention, and Figure 8 shows the SEM image and EBSD image of the super Invar alloy produced by the present invention.

[0118] Ordinary Invar alloys are typically composed of 64 at% iron and 36 at% nickel, while super Invar alloys generally consist of 59–65 at% iron, 30–36 at% nickel, and 4–7 at% cobalt. Additionally, the composition range of the most widely known commercially available super Invar alloys is 63–64 at% iron, 30–32 at% nickel, and 4–6 at% cobalt.

[0119] Figure 5 is a graph analyzing the composition of a super Invar alloy produced by the manufacturing method of the present invention, and it can be seen that a super Invar alloy containing about 60 at% iron, about 35 at% nickel, and about 5 at% cobalt was produced.

[0120] It is preferable to mix NCM and LFP in a ratio of 1:2 to 1:10 when mixing them into the cathode powder. The results of producing the super Invar alloy according to the mixing ratio of NCM and LFP may vary depending on variables such as the time, temperature, and pressure of the arc plasma process and the dephosphorization process variables described later. Generally, it was confirmed that the super Invar alloy is produced most effectively when mixed in a ratio of 1:2 to 1:10.

[0121] Figure 6 shows the results of analyzing the metal collected through the above three-step process using scanning electron microscopy energy-dispersive X-ray spectroscopy. Based on the data shown in Figure 6, it can be confirmed that the composition of iron, nickel, and cobalt in the portion excluding carbon is approximately 47 at%, 25 at%, and 5 at%, respectively, which is very similar to the composition of Super Invar. For reference, the experimental results in Figure 6 are the results of applying an arc plasma reaction by mixing NCM and LFP in a 1:5 ratio.

[0122] In addition, since there can be significant discrepancies regarding light elements such as carbon in the case of scanning electron microscopy energy dispersive X-ray spectroscopy, atomic tomography analysis was additionally performed, and the results are shown in Fig. 7.

[0123] As shown in Fig. 7, upon atomic tomography analysis, the composition of Super Invar was observed to be approximately 32 at% nickel, about 7 at% cobalt, and about 60 at% iron. Therefore, it can be seen that a Super Invar alloy can be obtained by utilizing metals through the arc plasma reduction reaction of the present invention.

[0124] In addition, Super Invar exhibits a face-centered cubic (FCC) crystal structure. As a result of the electron backscatter diffraction (EBSD) analysis shown in Fig. 7, it was confirmed that the Super Invar structure possesses an FCC crystal structure. Therefore, it was confirmed that a Super Invar alloy was manufactured in terms of microstructure and composition.

[0125] As the next step (4), the completeness of the super Invar alloy is improved through a dephosphorization process. To this end, calcium carbonate pellets are mixed with a reduction cathode material containing the super Invar alloy, and a hydrogen plasma reduction reaction is carried out again with the calcium carbonate mixed in. (S108)

[0126] In the case of the super Invar alloy obtained by the present invention, phosphorus (P) may be segregated in the crystal grains, which can adversely affect the thermal and mechanical properties of the alloy. Therefore, to improve the quality of the super Invar alloy, a process to remove phosphorus (P) originating from LFP powder is required.

[0127] In the present invention, a 'phosphorus-containing super Invar alloy' obtained through a process of steps 1 to 3 is mixed with calcium carbonate (CaCO3) pellets, and the mixed super Invar alloy is exposed to a hydrogen plasma. As described above, NCM and LFP can be mixed in a ratio of 1:2 to 1:10 in the cathode material powder introduced for the manufacture of the super Invar alloy, and it is preferable to introduce calcium carbonate powder in an amount equal to that of LFP powder.

[0128] In addition, it is desirable to manufacture calcium carbonate in pellet form and mix it with the cathode material pellets.

[0129] When a plasma oxidation reaction is carried out after mixing calcium carbonate pellets, the calcium oxide generated from the calcium carbonate can separate phosphorus from the superinvar alloy elements.

[0130]

[0131]

[0132] As the final fifth step, the dephosphorized and separated Super Invar alloy undergoes post-processing steps such as washing. (S110)

[0133]

[0134] 2nd embodiment

[0135]

[0136] In the present invention according to the first embodiment, a process is included in which calcium carbonate pellets are mixed with a metal (anode material including a super Invar alloy) produced as a result of a hydrogen plasma reduction reaction, and then phosphorus is removed through a second hydrogen plasma reduction reaction.

[0137] In the manufacturing method according to the second embodiment, a method of adding calcium carbonate in advance during the process of manufacturing the cathode material powder was applied.

[0138] As shown in FIG. 2, the cathode material of a waste lithium battery is extracted and crushed, and calcium carbonate powder is mixed with the cathode material powder and prepared in the form of pellets (S202, S204). That is, by mixing calcium carbonate in advance into the cathode material pellets to be fed into the hydrogen plasma reduction device (100), the process of removing phosphorus along with the production of the super invar alloy proceeds simultaneously during the hydrogen plasma reduction reaction.

[0139] The cathode material and calcium carbonate powder are mixed, compressed in a mold to form pellets, then introduced into a plasma chamber, and an arc plasma is generated in a hydrogen atmosphere to induce a reduction reaction. (S206)

[0140] Super Invar alloy generated through a plasma reduction reaction can be separated and collected as a ferromagnetic material, and an alloy material can be manufactured through post-processing. (S208, S210)

[0141] Figure 9 is an SEM image of a super Invar alloy manufactured by the manufacturing method according to the first embodiment, and Figure 10 is an SEM image of a super Invar alloy manufactured by the manufacturing method according to the second embodiment, confirming that super Invar alloys having similar compositions can be manufactured despite detailed differences in the two processes.

[0142] Figure 9 shows the result of manufacturing with the mixing ratio of NCM:LFP:CaCO3 set to 1:8:2, and Figure 10 shows the result of manufacturing with the mixing ratio of NCM:LFP:CaCO3 set to 1:6:6.

[0143]

[0144]

[0145] A method for manufacturing a high-entropy alloy by reducing spent lithium battery cathode material with arc plasma in a hydrogen atmosphere.

[0146]

[0147] This embodiment relates to a method for manufacturing a high-entropy alloy by arc plasma reduction of spent lithium battery cathode material in a hydrogen atmosphere, wherein the LiNi contained in the spent lithium battery cathode material is reduced using high-temperature arc plasma generated in a hydrogen atmosphere. 0.8 Co 0.1 Mn 0.1 The method is characterized by producing a high-entropy alloy reduced from O2 (NCM811; Lithium Nickel Cobalt Manganese Oxide), LiCoO2 (LCO; Lithium Cobalt Oxide), LiFePO4 (LFP; Lithium Iron Phosphate), etc.

[0148]

[0149] Third embodiment

[0150]

[0151] FIG. 11 is a flowchart showing the process of a method for manufacturing a high-entropy alloy according to a third embodiment of the present invention, FIG. 12 is a conceptual diagram showing the reaction process carrying out the process shown in FIG. 11, and FIG. 13 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0152] To carry out the high-entropy alloy manufacturing method of the present invention, a five-step process as shown in FIG. 11 is performed.

[0153] First, as a first step, a cathode material contained in a waste lithium battery is prepared. (S302) In the present invention, a high-entropy alloy was manufactured using NCM, LCO, and LFP cathode materials, but other cathode materials may be used.

[0154] The entire assembly, including the aluminum anode and the anode active material coated thereon, is separated from the spent lithium battery. When separating the anode material from the spent lithium battery, it is preferable to separate the anode material itself, excluding the negative electrode and separator contained within the battery cell. Since various methods can be applied to the technology for separating the anode material from the spent lithium battery, the present invention does not specifically limit the separation method.

[0155] The separated cathode material may contain a binder.

[0156] It is preferable to grind the separated cathode material into a powder form, and to grind it appropriately to a size suitable for introduction into a plasma chamber.

[0157] It is desirable to shape the crushed cathode material powder into a form optimized for the plasma reduction reaction. In the case of cathode material processed into powder form, it may be fed directly without processing, but it is preferable to pelletize the cathode material using a mold with a diameter of approximately 10 mm to 20 mm and feed it into the reduction chamber. Most preferably, pelletization can be carried out by compressing approximately 200 mg or more of cathode material to a pressure of 600 MPa or more using a mold with a diameter of 13 mm.

[0158] In the present invention, copper is mixed with pelletized cathode material powder. It is preferable to use copper from materials contained in spent lithium batteries, and in the present invention, high-purity copper foil used as a negative electrode current collector is used. Since the copper current collector is obtained in the form of a metal lump, it can be pelletized for use. Copper pellets are exposed to plasma together with NCM, LCO, and LFP mixed pellets. At this time, the mixing ratio is preferably set by weight as NCM:LCO:LFP:Cu = (5.5~8):(4~6):(1.5~3.5):(4.5~7). Most preferably, the composition is configured so that NCM:LCO:LFP:Cu = 6:5:2.4:6. However, the mixing ratio may vary when using actual cathode materials and copper current collectors from spent lithium batteries.

[0159] It is known that the magnetism of high-entropy alloys increases as the copper content increases. Therefore, by adding more copper, the magnetism of high-entropy alloys can be enhanced, thereby increasing their industrial utility value in applications such as electric generators, electric motors, and magnetic shielding materials.

[0160] As the next step, the cathode pellets and copper pellets are exposed to a plasma arc in a hydrogen atmosphere to induce a reduction reaction. (S306)

[0161] The initial state cathode material powder and copper pelletized in the previous step are introduced into a hydrogen plasma reduction device (100) to remove oxygen through a reduction reaction.

[0162] A hydrogen plasma reduction device (100) has a cathode (104) and an anode (106) installed inside a chamber (102), and a supply tank (108) for injecting gas for plasma generation may be provided on the outside. A gas pipe connected to the supply tank (108) is connected to a gas inlet (110) formed on one side of the chamber (102), and hydrogen and argon gases supplied from the supply tank (108) flow into the chamber (102) through the gas inlet (110).

[0163] A pressure gauge (112) and a thermometer (114) for measuring internal pressure and temperature, respectively, may be installed in the chamber (102).

[0164] Typically, the cathode (104) can be installed on the inner upper surface of the chamber (102) and extend vertically through the upper surface. The anode (106) is installed on the inner bottom surface of the chamber (102), and the anode material (20) before reduction can be placed on the anode (106). In the present invention, a mixture of anode material pellets and copper pellets is referred to as the 'anode material (20)'.

[0165] A power supply unit (not shown in the drawing) is connected to the cathode (104) and the anode (106), and power is supplied from the power supply unit to generate plasma between the cathode (104) and the anode (106).

[0166] When power is supplied to the cathode (104) and anode (106) while supplying a plasma gas, such as argon gas, through the gas inlet (110), an arc is generated at the electrical contact, changing the argon gas into a plasma state. The heat generated from the plasma melts the anode material (20) placed on the anode (106) before reduction, and the hydrogen supplied along with the argon gas causes a reduction reaction. The hydrogen combines with the oxygen bonded to the iron (Fe) and is discharged, leaving the anode material after reduction. The high-entropy alloy remains as a metallic element inside the anode material after reduction.

[0167] In the present invention, after placing the anode material (20) inside a Cu water-cooled chamber (maintained at 20°C), an arc plasma is generated in an argon and hydrogen mixed gas atmosphere while supplying a gas containing 90% argon and 10% hydrogen to reduce the oxide anode material (20) at a very high temperature.

[0168] It is preferable to set the pressure inside the chamber (102) to be in the range of -0.8 bar to -0.4 bar during the reduction reaction. It is also preferable to set the distance between the anode material specimen to be reduced and the plasma node to be about 1 cm. Furthermore, it is preferable to set the time for generating a plasma arc to cause the reduction reaction to occur to be 2 to 10 seconds.

[0169] In order to obtain a sufficient amount of high-entropy alloy from the cathode material (20) introduced, it is desirable to repeat the above plasma reduction reaction 2 to 6 times while setting the pressure, time, and distance between the cathode material specimen and the plasma node to be the same.

[0170] In the next step, the high-entropy alloy produced through the plasma reduction reaction and the impurity particles are separated (S308). When the high-entropy alloy produced through the plasma reduction reaction is contained within the anode material (20) in powder form, the pure high-entropy alloy can be collected by applying impact to the reduced powder.

[0171] Figure 14 shows an SEM image and EDS analysis results of a high-entropy alloy produced by the present invention, Figure 15 shows the XRD analysis results of a high-entropy alloy produced by the present invention, and Figure 16 shows an SEM image and EBSD image of a high-entropy alloy produced by the present invention.

[0172] The composition of an ideal quaternary high-entropy alloy must be synthesized such that each element is equal to or close to 25 at%. As a result of analyzing the alloy produced and collected by the manufacturing method of the present invention using scanning electron microscopy energy-dispersive X-ray spectroscopy, it was confirmed that the compositions of Fe, Co, Ni, and Cu were approximately 27 at%, 23 at%, 24 at%, and 26 at%, respectively, which is the composition of an ideal quaternary high-entropy alloy. Furthermore, since phosphorus (P), which is introduced into the alloy from LFP powder and adversely affects alloy performance (such as reduced ductility), was not detected, it was confirmed that the alloy can be obtained solely through hydrogen plasma exposure without an additional dephosphorization process.

[0173] In addition, it is known that in the case of high-entropy alloys, alloying elements must be dissolved in a single crystal structure such as FCC (Face-Centered Cubic) or BCC (Body-Centered Cubic). It has been reported that the FeCoNiCu high-entropy alloy has an FCC crystal structure. Through the X-ray diffraction test results in Fig. 15, it can be seen that the FeCoNiCu alloy synthesized using the technology of the present invention has an FCC single phase.

[0174] As shown in Fig. 16, it can be confirmed that it has an FCC single crystal structure in the results of electron backscatter diffraction (EBSD) analysis.

[0175] As the final fifth step, the separated high-entropy alloy undergoes post-processing steps such as washing. (S310)

[0176]

[0177] Method for manufacturing Ti-Al alloy by arc plasma reduction of spent lithium battery negative electrode material in a hydrogen atmosphere

[0178]

[0179] This embodiment relates to a method for manufacturing a Ti-Al alloy by arc plasma reduction of spent lithium battery negative electrode material in a hydrogen atmosphere, wherein the Li4Ti5O contained in the spent lithium battery negative electrode material is reduced using high-temperature arc plasma generated in a hydrogen atmosphere. 12 It is characterized by manufacturing a reduced Ti-Al alloy from (LTO; Lithium Titanate Oxide).

[0180]

[0181] FIG. 17 is a flowchart showing the process of a method for manufacturing a Ti-Al alloy according to the fourth embodiment of the present invention, FIG. 18 is a conceptual diagram showing the reaction process carrying out the process shown in FIG. 17, and FIG. 19 is a conceptual diagram showing the detailed structure of a plasma chamber.

[0182] To carry out the method for manufacturing the Ti-Al alloy of the present invention, a five-step process as shown in FIG. 17 is performed.

[0183] First, as a first step, a negative electrode material contained in a waste lithium battery is prepared. (S402) In the present invention, a Ti-Al alloy was manufactured using an LTO (Lithium Titanate Oxide) negative electrode material, but other negative electrode materials may be used.

[0184] LTO anode material is separated from spent lithium batteries that have been disposed of. When separating the anode material from the spent lithium batteries, it is preferable to separate the anode material itself, excluding the positive electrode and separator contained within the battery cell. Since various methods can be applied to the technology for separating the anode material from spent lithium batteries, the present invention does not specifically limit the separation method.

[0185] The separated cathode material may contain a binder.

[0186] It is preferable to grind the separated cathode material into a powder form, and to grind it appropriately to a size suitable for introduction into a plasma chamber.

[0187] It is desirable to shape the crushed cathode powder into a form optimized for the plasma reduction reaction. In the case of cathode material processed into powder form, it may be fed directly without processing, but it is preferable to pelletize the cathode material using a mold with a diameter of approximately 10 mm to 20 mm and feed it into the reduction chamber. Most preferably, pelletization can be carried out by compressing approximately 200 mg or more of cathode material to a pressure of 600 MPa or more using a mold with a diameter of 13 mm.

[0188] Then, aluminum pellets are prepared by pelletizing the aluminum current collector contained in the spent lithium battery (S404). It is preferable to use aluminum from the material contained in the spent lithium battery, and in the present invention, high-purity aluminum foil used as a positive current collector is used. Since the aluminum current collector is obtained in the form of a metal lump, it can be pelletized for use, and the aluminum pellets are mixed with LTO negative electrode material pellets and exposed to plasma. At this time, the mixing ratio is preferably LTO:AL = 1:2 to 1:5 by weight.

[0189] At this time, the mixing ratio for manufacturing the γ-TiAl alloy is most preferably LTO:Al = 1:3.4 by weight, and the mixing ratio for manufacturing the γ+α2-phase TiAl alloy is most preferably LTO:Al = 1:3.2 by weight. However, the mixing ratio may differ when using the negative electrode material of a waste lithium battery and the aluminum current collector.

[0190] As the next step, the cathode pellets and aluminum pellets are exposed to a plasma arc in a hydrogen atmosphere to induce a reduction reaction. (S406)

[0191] The initial state cathode material powder and aluminum pelletized in the previous step are introduced into a hydrogen plasma reduction device (100) to remove oxygen through a reduction reaction.

[0192] A hydrogen plasma reduction device (100) has a cathode (104) and an anode (106) installed inside a chamber (102), and a supply tank (108) for injecting gas for plasma generation may be provided on the outside. A gas pipe connected to the supply tank (108) is connected to a gas inlet (110) formed on one side of the chamber (102), and hydrogen and argon gases supplied from the supply tank (108) flow into the chamber (102) through the gas inlet (110).

[0193] A pressure gauge (112) and a thermometer (114) for measuring internal pressure and temperature, respectively, may be installed in the chamber (102).

[0194] Typically, the cathode (104) can be installed on the inner upper surface of the chamber (102) and extend vertically through the upper surface. The anode (106) is installed on the inner bottom surface of the chamber (102), and the cathode material (30) before reduction can be placed on the anode (106). In the present invention, a mixture of cathode material pellets and aluminum pellets is referred to as the 'cathode material (30)'.

[0195] A power supply unit (not shown in the drawing) is connected to the cathode (104) and the anode (106), and power is supplied from the power supply unit to generate plasma between the cathode (104) and the anode (106).

[0196] When power is supplied to the cathode (104) and anode (106) while supplying a plasma gas, such as argon gas, through the gas inlet (110), an arc is generated at the electrical contact, changing the argon gas into a plasma state. The heat generated from the plasma melts the pre-reduction cathode material (30) placed on the anode (106), and hydrogen supplied along with the argon gas causes a reduction reaction. The hydrogen combines with the oxygen bonded to the iron (Fe) and is discharged, leaving the post-reduction cathode material. The Ti-Al alloy remains as a metallic element inside the cathode material after reduction.

[0197] In the present invention, after placing the cathode material (30) inside a Cu water-cooled chamber (maintained at 20°C), an arc plasma is generated in an argon and hydrogen mixed gas atmosphere while supplying a gas containing 90% argon and 10% hydrogen to reduce the oxide cathode material (30) at a very high temperature.

[0198] It is preferable to set the pressure inside the chamber (102) during the reduction reaction to be in the range of -0.8 bar to -0.4 bar. It is also preferable to set the distance between the cathode material specimen to be reduced and the plasma node to be about 1 cm. And it is preferable to set the time for generating a plasma arc to cause the reduction reaction to be 30 seconds to 60 seconds.

[0199] In order to obtain a sufficient amount of Ti-Al alloy from the introduced cathode material (30), it is desirable to repeat the above plasma reduction reaction about 10 to 20 times while setting the pressure, time, and distance between the cathode material specimen and the plasma node to be the same.

[0200] In the next step, the Ti-Al alloy produced through the plasma reduction reaction and the impurity particles are separated (S408). When the Ti-Al alloy produced through the plasma reduction reaction is contained within the cathode material (30) in powder form, the pure Ti-Al alloy can be collected by applying impact to the reduced powder.

[0201] Figure 20 shows an SEM image and EDS analysis results of a Ti-Al alloy produced by the present invention, and Figure 21 shows an SEM image and EBSD image of a Ti-Al alloy produced by the present invention.

[0202] Commercially available γ-TiAl alloys for aircraft materials are γ-phase alloys with an Al composition of 49–65 at%. As a result of analyzing a Ti-Al alloy obtained with a weight ratio of LTO:Al = 1:3.4 using scanning electron microscopy energy-dispersive X-ray spectroscopy, it was confirmed that the compositions of Ti and Al were approximately 39.8 at% and 56.2 at%, respectively, which are very similar to the composition of an ideal γ-TiAl alloy. Through electron backscatter diffraction analysis (EBSD), it was confirmed that the alloy consists of a single γ-TiAl phase, thereby confirming the synthesis of a γ-TiAl alloy in terms of composition and microstructure.

[0203] In addition, by controlling the mixing ratio of LTO and Al, γ+α2 phase TiAl alloys used as lightweight, high-heat-resistant aircraft materials can also be designed using the technology of the present invention. The alloy obtained with a weight ratio of LTO:Al = 1:3.2 contains 35 to 48 at% Al and is characterized by a microstructure in which two phases, γ phase and α2 phase, coexist. Through the results of scanning electron microscopy energy-dispersive X-ray spectroscopy and electron backscatter diffraction analysis shown in Fig. 21, it was confirmed that the composition of the γ+α2 phase TiAl alloy synthesized using this patent technology contains 44 at% Al and exhibits a microstructure in which two phases, γ-TiAl and α2-TiAl, coexist.

[0204] By adjusting the LTO:Al mixing ratio during the process of manufacturing an alloy using the technology of the present invention, it is possible to produce all phases including α-Ti phase, β-Ti phase, α2-TiAl phase, and even TiAl intermetallic (intermetallic compound) alloy phases.

[0205] As the final fifth step, the separated and collected Ti-Al alloy undergoes post-processing steps such as washing. (S410)

[0206] Although preferred embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the technical configuration of the present invention described above may be implemented in other specific forms without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive, and the scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

1. A method for manufacturing a super Invar alloy from the cathode material of a spent lithium battery using arc plasma, wherein A first step of preparing a cathode material included in the above-mentioned spent lithium battery; A second step of exposing the above-mentioned anode material to a plasma arc to induce a reduction reaction; A third step for separating plasma-reduced super-Invar alloy and impurity particles; A method for producing a superinvar alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, comprising: a fourth step of mixing calcium carbonate into the separated superinvar alloy and exposing the superinvar alloy mixed with calcium carbonate to a plasma arc to induce a reduction reaction.

2. In Paragraph 1, A method for producing a super Invar alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, characterized in that, in the first step above, the cathode material is composed of a mixture of NCM and LFP, wherein the NCM and LFP are mixed in a ratio of 1:2 to 1:

10.

3. In Paragraph 2, A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, wherein the first step is characterized by grinding a cathode material composed of a mixture of the NCM and the LFP into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

4. In Paragraph 1, A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, wherein the second step above is characterized by introducing the oxidized cathode material into a hydrogen plasma reduction device (100) and reducing the cathode material in a hydrogen atmosphere.

5. In Paragraph 4, The above hydrogen plasma reduction device (100) is A chamber (102) in which a space is formed inside; A cathode (104) installed on the inner upper surface of the chamber (102); An anode (106) installed on the inner bottom surface of the chamber (102); A power supply unit connected to the above-mentioned negative electrode (104) and the above-mentioned positive electrode (106) to supply power; A supply tank (108) for supplying gas for plasma generation; A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in an arc plasma atmosphere in a hydrogen atmosphere, comprising: a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

6. In Paragraph 5, A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in a hydrogen atmosphere using arc plasma, characterized in that the supply tank (108) stores hydrogen and argon gas and supplies it into the chamber (102).

7. In Paragraph 6, A method for producing a super Invar alloy by reducing a spent lithium battery cathode material in a hydrogen atmosphere using arc plasma, characterized in that the supply tank (108) supplies a gas containing 90% argon and 10% hydrogen.

8. In Paragraph 1, A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in a hydrogen atmosphere using arc plasma reduction, wherein the third step above involves reducing a magnetic material having magnetic force and bringing it close to the cathode material to separate the super Invar alloy.

9. In Paragraph 1, A method for producing a superinvar alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, further comprising a fifth step of washing and post-treating the separated superinvar alloy.

10. In Paragraph 1, The above super-invar alloy contains iron, nickel, and cobalt, and The above iron has a composition ratio of 59 at% to 65 at%, and The above nickel has a composition ratio of 30 at% to 36 at%, and A method for producing a super Invar alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, characterized in that the above-mentioned cobalt has a composition ratio of 4 at% to 7 at%.

11. A method for manufacturing a super Invar alloy from the cathode material of a spent lithium battery using arc plasma, wherein A first step of preparing a cathode material included in the above-mentioned spent lithium battery; A second step of exposing the above-mentioned anode material to a plasma arc to induce a reduction reaction; A method for producing a super Invar alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, comprising a third step of separating the plasma-reduced super Invar alloy and impurity particles.

12. In Paragraph 11, A method for producing a super Invar alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, characterized in that, in the first step above, the cathode material is composed of a mixture of NCM and LFP, wherein the NCM and LFP are mixed in a ratio of 1:2 to 1:10, and calcium carbonate (CaCO3) is additionally mixed into the mixture of NCM and LFP.

13. In Paragraph 12, A method for producing a super Invar alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, wherein the first step is characterized by grinding a cathode material composed of a mixture of the NCM, the LFP, and the calcium carbonate into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

14. A method for manufacturing a high-entropy alloy from the cathode material of a spent lithium battery using arc plasma, wherein A first step of preparing a cathode material pellet using the cathode material contained in the above-mentioned waste lithium battery; A second step of preparing copper pellets using the negative current collector included in the above-mentioned waste lithium battery; A third step of exposing a mixture of the above-mentioned anode material pellets and the above-mentioned copper pellets to a plasma arc to induce a reduction reaction; A method for producing a high-entropy alloy by reducing a spent lithium battery cathode material in an arc plasma atmosphere, comprising: a fourth step of separating the plasma-reduced high-entropy alloy and impurity particles.

15. In Paragraph 14, A method for producing a high-entropy alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, characterized in that, in the first step above, the cathode material pellet is composed of a mixture of NCM, LCO, and LFP, wherein the NCM, LCO, and LFP are mixed in a weight ratio of (5.5~8):(4~6):(1.5~3.5).

16. In Paragraph 15, A method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, wherein the first step is characterized by grinding a cathode material composed of a mixture of the NCM, the LCO, and the LFP into a powder form, and compressing the cathode material processed into a powder form in a mold to form pellets.

17. In Paragraph 15, A method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, characterized in that, in the second step above, the copper pellet is formed by pelletizing a negative electrode current collector in the form of copper foil contained in the waste lithium battery.

18. In Paragraph 17, A method for producing a high-entropy alloy by reducing a spent lithium battery cathode material in an arc plasma in a hydrogen atmosphere, characterized in that the copper contained in the above NCM, above LCO, above LFP, and above copper pellets is mixed in a weight ratio of (5.5~8):(4~6):(1.5~3.5):(4.5~7).

19. In Paragraph 14, The above third step is characterized by introducing the cathode material, which is a mixture of the cathode material pellet and the copper pellet, into a hydrogen plasma reduction device (100) and reducing the cathode material in a hydrogen atmosphere, a method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere.

20. In Paragraph 19, The above hydrogen plasma reduction device (100) is A chamber (102) in which a space is formed inside; A cathode (104) installed on the inner upper surface of the chamber (102); An anode (106) installed on the inner bottom surface of the chamber (102); A power supply unit connected to the above-mentioned negative electrode (104) and the above-mentioned positive electrode (106) to supply power; A supply tank (108) for supplying gas for plasma generation; A method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma atmosphere in a hydrogen atmosphere, comprising: a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

21. In Paragraph 20, A method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma atmosphere in a hydrogen atmosphere, characterized in that the supply tank (108) stores hydrogen and argon gas and supplies it into the interior of the chamber (102).

22. In Paragraph 21, A method for producing a high-entropy alloy by reducing a spent lithium battery cathode material in an arc plasma atmosphere, characterized in that the supply tank (108) supplies a gas containing 90% argon and 10% hydrogen.

23. In Paragraph 14, A method for producing a high-entropy alloy by reducing a waste lithium battery cathode material in an arc plasma in a hydrogen atmosphere, further comprising a fifth step of washing and post-treating the separated high-entropy alloy.

24. In Paragraph 14, The above high-entropy alloy includes iron, cobalt, nickel, and copper, and The above iron has a composition ratio of 25 at% to 28 at%, and The above cobalt has a composition ratio of 22 at% to 24 at%, and The above nickel has a composition ratio of 23 at% to 25 at%, and A method for producing a high-entropy alloy by arc plasma reduction of a spent lithium battery cathode material in a hydrogen atmosphere, characterized in that the copper has a composition ratio of 25 at% to 27 at%.

25. A method for manufacturing a Ti-Al alloy from the negative electrode material of a spent lithium battery using arc plasma, wherein A first step of preparing a negative electrode pellet using the negative electrode material contained in the above-mentioned waste lithium battery; A second step of preparing aluminum pellets using the aluminum current collector contained in the above-mentioned waste lithium battery; A third step of exposing a mixture of the above-mentioned cathode material pellets and the above-mentioned aluminum pellets to a plasma arc to induce a reduction reaction; A method for producing a Ti-Al alloy by arc plasma reduction of a spent lithium battery negative electrode material in a hydrogen atmosphere, comprising: a fourth step of separating the plasma-reduced Ti-Al alloy and impurity particles.

26. In Paragraph 25, A method for producing a Ti-Al alloy by arc plasma reduction of a spent lithium battery negative electrode material in a hydrogen atmosphere, characterized in that, in the first step above, the negative electrode pellet is composed of an LTO (Lithium Titanate Oxide) negative electrode material, and the LTO and the aluminum are mixed in a weight ratio of LTO:Al = 1:2 to 1:

5.

27. In Paragraph 26, A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in an arc plasma in a hydrogen atmosphere, wherein the first step above involves crushing the negative electrode material composed of the LTO into a powder form and compressing the negative electrode material processed into a powder form in a mold to form pellets.

28. In Paragraph 26, A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in an arc plasma in a hydrogen atmosphere, characterized in that, in the second step above, the aluminum pellets are formed by pelletizing and using a current collector in the form of aluminum foil contained in the waste lithium battery.

29. In Paragraph 25, A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in an arc plasma in a hydrogen atmosphere, wherein the third step above involves introducing a negative electrode material mixed with the negative electrode material pellet and the aluminum pellet into a hydrogen plasma reduction device (100) and reducing the negative electrode material in a hydrogen atmosphere.

30. In Paragraph 29, The above hydrogen plasma reduction device (100) is A chamber (102) in which a space is formed inside; A cathode (104) installed on the inner upper surface of the chamber (102); An anode (106) installed on the inner bottom surface of the chamber (102); A power supply unit connected to the above-mentioned negative electrode (104) and the above-mentioned positive electrode (106) to supply power; A supply tank (108) for supplying gas for plasma generation; A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in an arc plasma atmosphere in a hydrogen atmosphere, comprising: a gas inlet (110) formed on one side of the chamber (102) and connected to a gas pipe connected to the supply tank (108).

31. In Paragraph 30, A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in a hydrogen atmosphere using arc plasma, wherein the supply tank (108) stores hydrogen and argon gas and supplies it into the chamber (102).

32. In Paragraph 31, A method for producing a Ti-Al alloy by reducing a spent lithium battery negative electrode material in a hydrogen atmosphere using arc plasma, characterized in that the supply tank (108) supplies a gas containing 90% argon and 10% hydrogen.

33. In Paragraph 25, A method for producing a Ti-Al alloy by reducing a waste lithium battery negative electrode material in an arc plasma in a hydrogen atmosphere, further comprising a fifth step of washing and post-treating the separated Ti-Al alloy.

34. In Paragraph 26, A method for producing a Ti-Al alloy by arc plasma reduction of a spent lithium battery negative electrode material in a hydrogen atmosphere, wherein the γ-TiAl alloy, prepared by mixing the above LTO and the above aluminum in a weight ratio of LTO:Al = 1:3.4, is characterized in that the composition of Ti and Al is 39.8 at% and 56.2 at%, respectively.

35. In Paragraph 26, A method for producing a Ti-Al alloy by arc plasma reduction of a spent lithium battery negative electrode material in a hydrogen atmosphere, wherein the γ+α2-phase TiAl alloy, prepared by mixing the above LTO and the above aluminum in a weight ratio of LTO:Al = 1:3.2, is characterized by having an Al composition of 44 at%.

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