Method for disassembling chemical battery

Abstract

Provided is a method for disassembling a chemical battery, wherein a recovery rate of 95% or more for cobalt and nickel and a recovery rate of 80% or more for lithium are achieved for the chemical battery, and the method contributes to the recovery of valuable metals from the chemical battery. A method for disassembling a chemical battery comprises: an electrode assembly separation step in which the casing of the chemical battery is cut and the electrode assembly is taken out from the inside of the casing; a first peeling step in which a fixing portion of the electrode assembly obtained in the electrode assembly separation step is peeled off; and a second peeling step in which each of a positive electrode foil, a separator, and a negative electrode foil constituting the electrode assembly is peeled off. Another method for disassembling a chemical battery comprising a casing, an electrode assembly, an electrode terminal plate, and a current collector, the electrode assembly and the electrode terminal plate being electrically connected via the current collector, comprises a cutting step in which the casing and the current collector are cut. A method for disassembling a chemical battery comprising a casing, an electrode assembly, an electrode terminal plate, and a current collector comprises: a cutting step in which the casing and the current collector are cut; and an electrode assembly separation step in which the electrode assembly is extruded by an auxiliary unit.

Description

How to disassemble a chemical battery

[0001] The present invention relates to a method for disassembling a chemical battery.

[0002] With the widespread use of lithium-ion batteries, competition to secure the valuable metals used in lithium-ion batteries is intensifying. In addition to the depletion of these valuable metal resources, resource-rich countries are concerned about environmental destruction and forced labor caused by excessive mining development. Resource-poor countries are concerned about securing stable supplies and fluctuations in procurement prices. To reduce the environmental impact of excessive mining development and waste disposal, methods are being considered for recovering valuable metals such as cobalt, nickel, manganese, and lithium from discarded lithium-ion batteries and reusing them as materials for lithium-ion batteries. In recent years, the recycling rate of lithium-ion batteries has become increasingly important, and not only are valuable metals such as cobalt, nickel, and lithium contained in the cathode material being recovered, but also carbon and copper contained in the anode material, and even the separator itself. In Europe, battery regulations came into effect on August 17, 2023, requiring recovery rates of cobalt and nickel in lithium-ion batteries to be at least 95% and lithium to be at least 80% by 2031.

[0003] Furthermore, the environmental impact of lithium-ion battery recycling is also attracting attention. As we move towards a decarbonized society, efforts to prevent greenhouse gas emissions are being sought in the recycling business.

[0004] Patent Document 1 discloses a system in which used lithium ion batteries or lithium ion batteries discarded as defective products during the manufacturing process are discharged, then heated (roasted), and then crushed in a crusher such as a hammer mill or jaw crusher, and the casings, current collectors, and other components of the discarded lithium ion batteries are removed (classified) by sieving to obtain active material powder, and the active material powder is then processed to recover lithium.

[0005] Patent No. 7060899

[0006] The system for recovering lithium from used lithium-ion batteries disclosed in Patent Document 1 has the problem that valuable metals remain on the sieve during sieving, resulting in a loss of 5% or more of cobalt and nickel, making it impossible to achieve the recycling rate stipulated in the Battery Regulations. Furthermore, in conventional recycling methods for used lithium-ion batteries, carbon powder and organic matter are roasted to obtain active material powder, which generates carbon dioxide. Therefore, there has been a demand for a recycling method for used lithium-ion batteries that does not involve roasting and obtains active material powder.

[0007] The problem to be solved by the present invention is to provide a method for disassembling a chemical battery that contributes to the recovery of valuable metals from a chemical battery, achieving a recovery rate of 95% or more for cobalt and nickel and 80% or more for lithium in the chemical battery. Another problem to be solved by the present invention is to provide a method for disassembling a chemical battery that does not require roasting and suppresses the generation of carbon dioxide.

[0008] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that a method for disassembling a chemical battery, which includes an electrode assembly separation step in which the casing of the chemical battery is cut and the electrode assembly is removed from inside the casing, achieves the recycling rate stipulated in the Battery Regulations and contributes to a method for recovering valuable metals from chemical batteries without the need for roasting. The first invention of the present application was completed based on these findings.

[0009] The present inventors have found that a method for disassembling a chemical battery, in which an electrode assembly and an electrode terminal plate are electrically connected via a current collector, including a cutting step of cutting the casing and the current collector, contributes to a method for recovering valuable metals from chemical batteries that achieves the recycling rate stipulated in the Battery Regulations. The second invention of the present application has been completed based on these findings.

[0010] The present inventors have found that a method for disassembling a chemical battery, which includes a step of cutting the casing and current collector of the chemical battery and a step of extruding the electrode assembly by an extrusion unit inserted through the holes formed in the drilling step, achieves the recycling rate stipulated in the Battery Regulations and contributes to a method for recovering valuable metals from chemical batteries without the need for roasting. The third invention of the present application was completed based on these findings.

[0011] The present inventors have found that a method for disassembling a lithium ion battery, in which a tape securing an end of a separator constituting an electrode assembly removed from the lithium ion battery is peeled off with a brush to open the ends of the positive electrode assembly, separator, and negative electrode assembly constituting the electrode assembly, contributes to a method for recovering valuable metals from lithium ion batteries that achieves the recycling rate stipulated in the Battery Regulations. The fourth invention of the present application has been completed based on these findings.

[0012] The present inventors have discovered that a method for disassembling a chemical battery, which includes a first peeling step of peeling off the ends of two separators of an electrode assembly having a laminate in which a positive electrode foil, a first separator, a negative electrode foil, and a second separator are stacked in this order, achieves the recycling rate stipulated in the Battery Regulations and contributes to a method for recovering valuable metals from chemical batteries without the need for roasting. The fifth invention of the present application was completed based on these findings.

[0013] The first invention of the present application relates to a method for disassembling a chemical battery, the method including: an electrode body separation step in which a casing of the chemical battery is cut and an electrode body is removed from inside the casing; a first peeling step in which a fixing portion of the electrode body obtained in the electrode body separation step is peeled off; and a second peeling step in which a positive electrode foil, a separator, and a negative electrode foil that constitute the electrode body are each peeled off, and the fixing portion of the electrode body is located at an end of the separator.

[0014] A second invention of the present application relates to a method for disassembling a chemical battery, the chemical battery comprising a casing, an electrode assembly, an electrode terminal plate, and a current collector, the electrode assembly and the electrode terminal plate being electrically connected via the current collector, the method including a cutting step of cutting the casing and the current collector. Preferably, the casing is box-shaped, and the casing and the current collector are cut in a direction perpendicular to the surface on which the electrode terminal plate is attached. The cutting location is preferably at least one selected from the group consisting of the positive electrode terminal plate side and the negative electrode terminal plate side. The cutting location is more preferably the positive electrode terminal plate side and the negative electrode terminal plate side, and the cutting is performed in the order of the positive electrode terminal plate side and then the negative electrode terminal plate side, or the negative electrode terminal plate side and then the positive electrode terminal plate side. The casing and the current collector are more preferably cut from the surface on which the positive electrode terminal plate and the negative electrode terminal plate are attached in a direction facing the surface.

[0015] A third invention of the present application relates to a method for disassembling a chemical battery, the chemical battery comprising a casing, an electrode assembly, an electrode terminal plate, and a current collector, the method including a cutting step in which the casing and the current collector are cut, and an electrode assembly separation step in which the electrode assembly is pushed out by an auxiliary unit. The third invention of the present application preferably further includes a perforating step in which the casing is perforated. Preferably, the casing is box-shaped, and the end of the casing and the current collector are cut in a direction perpendicular to the surface on which the electrode terminal plate is attached in the cutting step, and the end of the casing opposite the end cut in the cutting step is perforated in the perforating step. Preferably, the casing and current collector on the negative electrode terminal plate side are cut in the cutting step. Preferably, an auxiliary unit is used, and the electrode assembly is pushed out in a direction parallel to the surface on which the electrode terminal plate is attached in the pushing step.

[0016] A fourth invention of the present application relates to a method for disassembling a chemical battery, the method including a first peeling step in which an end of an electrode assembly is peeled and opened, the electrode assembly being configured by winding a cathode foil and an anode foil via a separator, the end of which is fixed. Preferably, a brush is brought into contact with the end of the separator, which is fixed with an adhesive material, and the end of the separator is peeled off. More preferably, the brush is rotating. More preferably, the brush has a structure in which spiral protrusions are formed on a shaft and bristles are provided on the protrusions. The material of the bristles of the brush is preferably at least one selected from the group consisting of resin, metal, animal-derived, and plant-derived. The rotation speed of the brush is preferably in the range of 60 to 3000 rpm. Preferably, the fixed end of the separator is cut off, and the end of the separator is peeled off. Preferably, a resin roller is brought into contact with an end of the separator, which is fixed with an adhesive material, and the end of the separator is peeled off. Preferably, the end of the separator is fixed with tape, and the tape is peeled off with a tape remover, and the end of the separator is peeled off. The chemical battery disassembly method preferably further includes a pretreatment step in which the lithium ion battery is discharged and then the electrolyte in the lithium ion battery is extracted, an electrode assembly separation step in which cells of the lithium ion battery obtained in the pretreatment step are cut and electrode bodies are pushed out and removed from the inside of the cells, and a second peeling step in which the positive electrode body, separator, and negative electrode body are each peeled off.

[0017] A fifth invention of the present application relates to a method for disassembling a chemical battery, the method including a first peeling step of peeling off ends of two separators constituting an electrode assembly, the electrode assembly including a laminate in which a positive electrode foil, a first separator, a negative electrode foil, and a second separator are stacked in this order, and end portions of the first separator and the second separator are fixed. The first peeling step preferably includes a peeling unit insertion step of inserting a peeling unit for the first separator and the second separator into a gap after a gap is formed between the ends of the first separator and the second separator. More preferably, the gap is formed by sucking the first separator and the second separator with a suction unit. More preferably, the peeling unit includes a rod. The chemical battery disassembly method of the fifth invention preferably further includes a pretreatment step in which the lithium ion battery is discharged and then the electrolyte in the lithium ion battery is extracted, an electrode body separation step in which the lithium ion battery cells obtained in the pretreatment step are cut and the electrode bodies are pushed out from the inside of the cells and removed, and a second separation step in which the positive electrode body, separator, and negative electrode body are each separated.

[0018] The chemical battery is more preferably a secondary battery, and even more preferably the secondary battery is a lithium ion battery.

[0019] The methods for disassembling chemical batteries according to the first to fifth aspects of the present application achieve the recycling rate stipulated in the Battery Regulations, and provide methods for disassembling chemical batteries that contribute to a method for recovering valuable metals from chemical batteries without the need for roasting.

[0020] 1 is an explanatory diagram showing the configuration of one embodiment of a method for disassembling a chemical battery according to the first to fifth aspects of the present invention; FIG. 2 is a cross-sectional view of a chemical battery 1, which is one embodiment of a chemical battery; FIG. 3 is an explanatory diagram showing a first embodiment of a cutting step; FIG. 4 is an explanatory diagram showing a second embodiment of a cutting step; FIG. 5 is an explanatory diagram showing a state in which an electrode body 3 is being pushed out from inside a casing; FIG. 6 is an explanatory diagram showing a state in which an electrode body 3 is being pushed out from inside a casing; FIG. 7 is an explanatory diagram showing four modes of the shape and size of holes formed in the drilling step; FIG. 8 is an explanatory diagram showing one embodiment of a rotating brush; FIG. 9 is an explanatory diagram showing one embodiment in which a rotating brush is in contact with an electrode body; FIG. 10 is a cross-sectional view showing one embodiment of an electrode body disassembled in the fifth aspect of the present invention; FIG. 11 is an explanatory diagram of one embodiment of a first peeling step of the fifth aspect of the present invention; FIG. 12 is an explanatory diagram of one embodiment of a first peeling step of the fifth aspect of the present invention; FIG. 13 is an explanatory diagram of one embodiment of a second peeling step of the fifth aspect of the present invention.

[0021] The first to fifth inventions of the present application will be described in more detail. Unless otherwise specified, the "to" in a numerical range indicates a range from above to below, and both end values ​​are included. Furthermore, when a numerical range is indicated, the upper and lower limits can be combined as appropriate, and the resulting numerical range is also considered to be disclosed.

[0022] The disassembly methods for chemical batteries according to the first to fifth aspects of the present invention may include a discharging step (STEP A in FIG. 1 ) of discharging the chemical battery to reduce residual charge. It is desirable that the residual charge be as small as possible. Chemical batteries generate electricity through internal chemical reactions and extract the electrical energy. They are classified into three types: primary batteries, secondary batteries, and fuel cells. A preferred chemical battery is a secondary battery, and a more preferred chemical battery is a lithium-ion battery. The chemical battery may include at least one selected from the group consisting of used chemical batteries and chemical batteries discarded as defective products during the manufacturing process.

[0023] <Cutting Step> The disassembly method for a chemical battery according to the second and third aspects of the present invention includes a cutting step in which the casing and the current collectors are cut, and the disassembly method for the fourth and fifth aspects of the present invention may include this cutting step. FIG. 2 is a cross-sectional view of a chemical battery 1, which is one embodiment of a chemical battery. The chemical battery 1 includes a casing 2, an electrode assembly 3, an electrode terminal plate 4 (positive electrode 4a and negative electrode 4b), and current collectors 5 (positive electrode current collector 5a and negative electrode current collector 5b), and the electrode assembly 3 and the electrode terminal plate 4 are covered by the casing 2. The electrode assembly 3 and the electrode terminal plate 4 are electrically connected via the current collector 5. The disassembly method for a chemical battery according to the second and third aspects of the present invention includes a cutting step in which the casing 2 and the current collectors 5 are cut, and the first, fourth, and fifth aspects of the present invention may include this cutting step. In the cutting step, the casing 2 and the electrode assembly 3 can be easily separated from each other without damaging the electrode assembly 3.

[0024] FIG. 3 is an explanatory diagram showing a first embodiment of the cutting step. The casing 2 is box-shaped, and the casing 2 and the current collector 5 are cut in a direction perpendicular to the surface on which the electrode terminal plate 4 is attached. The cutting location is at least one selected from the group consisting of the positive electrode 4a side (dashed line on the left side of FIG. 3 ) and the negative electrode 4b side (dashed line on the right side of FIG. 3 ). By cutting in this direction, the casing 2 and the current collector 5 are simultaneously cut, and the casing 2 and the electrode body 3 are easily separated. When the cutting locations are the positive electrode 4a side and the negative electrode 4b side, the cutting is preferably performed in the order of the positive electrode 4a side and then the negative electrode 4b side, or the negative electrode 4b side and then the positive electrode 4a side. If the positive electrode 4a side and the negative electrode 4b side are cut simultaneously, there is a risk of current flow through the cutting machine, which is a safety hazard. By cutting in the above order, the risk of current flow can be reduced. Furthermore, the casing 2 and the current collector 5 are preferably cut from the surface (upper side in FIG. 3 ) on which the positive electrode 4 a and the negative electrode 4 b are attached in the direction opposite to that surface (lower side in FIG. 3 ) (the direction of the arrow in FIG. 3 ). The current collector 5 is weak and may shift in position when cut. In particular, cutting in this direction prevents the current collector 5 from shifting in position, allowing for accurate cutting and high reproducibility of the cut.

[0025] FIG. 4 is an explanatory diagram showing a second embodiment of the cutting process. The casing 2 is box-shaped, and the casing 2 and the current collector 5 are cut in a direction parallel to the surface on which the electrode terminal plate 4 is attached. The cutting location is the side of the casing 2 on which the electrode terminal plate 4 is attached (the lower side in FIG. 4 ). In the second embodiment, the casing 2 is preferably cut so that the electrode assembly 3 falls under its own weight. If the side opposite to the side on which the electrode terminal plate 4 is attached (the upper side in FIG. 4 ) is cut, the casing 2 and the electrode assembly 3 are in contact at the cut location, and the electrode assembly 3 will also be caught and cut. Furthermore, to separate the casing 2 and the electrode assembly 3, the current collector 5 must be cut separately. Therefore, cutting the side of the casing 2 on which the electrode terminal plate 4 is attached is preferable to cutting the side opposite to the side on which the electrode terminal plate 4 is attached.

[0026] In a second embodiment of the cutting step, a gas injection step is preferably performed before the cutting step. The gas injection step involves drilling at least one hole in the casing 2 and injecting gas through the hole. The hole is drilled at any location in the casing 2. The gas includes an inert gas, preferably an inert gas. The inert gas includes at least one selected from the group consisting of air, carbon dioxide, nitrogen, helium, neon, argon, krypton, and xenon, preferably at least one selected from the group consisting of air, carbon dioxide, and nitrogen, and more preferably air, carbon dioxide, or nitrogen. The electrode body 3 is tightly packed in the casing 2, and therefore has high resistance when falling due to its own weight. In the gas injection step, the casing 2 expands by injecting the gas, thereby reducing resistance when falling.

[0027] A band saw may be used in the electrode assembly separating step of the first invention and the cutting step of the chemical battery disassembly methods of the second to fifth inventions, which will be described later. The blade feed speed of the band saw is preferably in the range of 35 m / min or more. When the blade feed speed is in this range, the casing can be cut without generating burrs. At least one selected from the group consisting of a water jet and a laser cutter may be used instead of the band saw.

[0028] In the electrode body separation step of the first invention and the cutting step of the chemical battery disassembly methods of the second to fifth inventions, the casing 2 and the current collector 5 are preferably cut in the presence of a cooling solvent. The cooling solvent preferably contains water or silicone oil, more preferably contains water, and even more preferably is water. When the cooling solvent is used, heat generation during cutting is suppressed. Furthermore, the casing and the current collector are preferably cut in the presence of an inert gas in the cutting step. The inert gas used in the cutting step is the same as the inert gas used when drilling holes. When the inert gas is used in the cutting step, heat generation during cutting is also suppressed.

[0029] <Electrode Assembly Separation Step> The disassembly method for a chemical battery according to the first invention includes an electrode assembly separation step (STEP 1 in FIG. 1 ) in which the casing of the chemical battery is cut and the electrode assembly is removed from the inside of the casing. The disassembly methods for a chemical battery according to the second, fourth, and fifth inventions may also include this electrode assembly separation step. The electrical connection between the electrode assembly 3 and the electrode terminal plate 4 via the current collector 5 is severed in the cutting step. In the first embodiment of the cutting step, the electrode assembly 3 is pushed out from the inside of the casing and removed from the side where the casing 2 and current collector 5 are cut. FIG. 5 is an explanatory diagram showing the electrode assembly 3 being pushed out from the inside of the casing 2. The electrode assembly 3 is pushed toward the positive electrode 4a (in the direction of the arrow in FIG. 5 ) and removed from the positive electrode 4a side. The electrode assembly 3 may also be removed from the negative electrode 4b side.

[0030] In the electrode body separation step of the first invention, the casing is cut and the electrode body is removed from inside the casing. The electrode body separation step of the first invention makes it possible to separate aluminum derived from the casing that is not needed as active material powder. In existing methods, aluminum is crushed together with the electrode body, sieved, and separated. In this process, the valuable metals remain on the sieve, reducing the recovery rate of the valuable metals. This inconvenience is resolved in the electrode body separation step, making it possible to suppress a decrease in the recovery rate of the valuable metals. Furthermore, because the separated casing is not mixed with other materials, it can be recycled as an aluminum resource as is. After the casing is cut in the electrode body separation step, the electrolyte in the casing is recovered as a resource.

[0031] The disassembling method for a chemical battery of the third invention includes an electrode assembly separation step in which the electrode assembly is extruded by an extrusion unit. If the cutting locations are on the positive electrode 4a side and the negative electrode 4b side, the electrode assembly may be extruded from the casing by an extrusion unit moving from the positive electrode 4a side or the negative electrode 4b side. If the disassembling method for a chemical battery of the present invention includes a drilling step described below, the electrode assembly may be extruded from the casing by an extrusion unit inserted through the hole formed in the drilling step. Figure 4 is an explanatory diagram showing the electrode assembly 3 being extruded from inside the casing 2. Using an extrusion unit 7, the electrode assembly 3 is extruded toward the positive electrode 4a side parallel to the surface on which the electrode terminal plate 4 is attached (in the direction of the arrow in Figure 6). The electrode assembly 3 may be removed from the negative electrode 4b side.

[0032] The portion of the extrusion unit 7 that comes into contact with the electrode body may be in the form of one or more rods. The shape of the tip of the rod is not limited to a particular shape. The shape of the tip includes at least one selected from the group consisting of a sphere, a cone, a triangular pyramid, and a square pyramid.

[0033] A step corresponding to the thickness of the casing may occur between the lower surface of the electrode assembly and the floor during the electrode assembly separation process, which may damage the outermost separator of the electrode assembly. To prevent this damage, an auxiliary unit 8 may be used to fill the step. The auxiliary unit 8 is not limited to a specific unit. An example of the auxiliary unit 8 is a roller.

[0034] The electrode body separation step of the third invention also makes it possible to separate aluminum derived from the casing, which is not required as active material powder.

[0035] <Perforation Step> The method for disassembling a chemical battery according to the third aspect of the present invention may include a perforation step in which the casing is perforated. The perforations may be made at any location in the casing. The perforation step may be performed before, after, or simultaneously with the cutting step. The number of holes formed in the perforation step is one or more. The shape of the holes formed in the perforation step is not limited to a specific shape. The shape may include at least one selected from the group consisting of a circle, a polygon, and a star.

[0036] 7A and 7B are explanatory diagrams showing four modes of the shape and size of the hole formed in the perforation step. When the hole formed in the perforation step is circular, the diameter of the circle may be the smallest size through which the extrusion unit can pass (FIG. 7A), or may be from one end of the casing to the other end (FIG. 7B). When the hole formed in the perforation step is rectangular, the size of the rectangle may be the smallest size through which the extrusion unit can pass (FIG. 7C), or may be the entire casing (FIG. 7D).

[0037] The disassembly method for a chemical battery according to the third aspect of the present invention may further include an inert gas injection step of injecting an inert gas into the holes formed in the perforation step. When the casing is inflated by the inert gas, the electrode assembly is more easily removed in the electrode assembly separation step described below. The inert gas includes at least one selected from the group consisting of carbon dioxide, nitrogen, helium, neon, argon, krypton, and xenon, preferably at least one selected from the group consisting of carbon dioxide and nitrogen, and more preferably carbon dioxide or nitrogen.

[0038] <First Peeling Step> The electrode assembly of a chemical battery disassembled by the chemical battery disassembly methods of the first to fourth inventions includes a positive electrode foil, a separator, and a negative electrode foil. The positive electrode foil, separator, and negative electrode foil constituting the electrode assembly are all film-like. The positive electrode foil is disposed on one side of the separator, and the negative electrode foil is disposed on the other side of the separator, and these are wound, folded, or the like to form a single unit. The end of the separator is fixed with a fixing means such as tape, adhesive, or crimping; i.e., the fixed portion of the electrode assembly is located at the end of the separator. If the positive electrode foil and the negative electrode foil can be separated, the chemical battery disassembly methods of the first and fourth inventions may include a first peeling step (STEP 2 in FIG. 1 ) in which the fixed portion of the electrode assembly obtained in the electrode assembly separation step is peeled off, and the chemical battery disassembly methods of the second and third inventions may include this first peeling step (STEP 2 in FIG. 1 ). In the first peeling step, the fixing portion is peeled off by a peeling unit. The peeling unit is not limited to a specific peeling unit. Examples of the peeling unit include a brush, a cutting unit, a roller, a tape remover, a scraper, etc. Although peeling off the fixing portion has not been considered in the past, automation of peeling off the fixing portion has been considered in the chemical battery disassembly methods of the first to fourth inventions. Note that the first peeling step is not performed manually but by the peeling unit. The end of the separator on which the positive electrode foil is disposed and the end of the separator on which the negative electrode foil is disposed, which are peeled off in the first peeling step, respectively, become the start of winding in the second peeling step described below.

[0039] The preferred peeling unit is a brush. The preferred brush is a rotary brush. The rotation speed of the rotary brush is preferably in the range of 60 rpm or higher. More preferably, the rotary brush 9 has a structure in which spiral protrusions 10 are formed on a rotation shaft 20, and the protrusions 10 are formed by bristles (see FIG. 8). When the end of the separator is fixed with tape 21, the rotary brush 9 is rotated while the protrusions 10 formed by the bristles are brought into contact with the surface including the tape 21 so that the rotation shaft 20 of the rotary brush 9 is parallel to the surface of the film-like positive electrode body, separator, and negative electrode body, and the tape 21 is peeled off (see FIG. 9).

[0040] The rotating brush 9 may have a structure in which a rotation axis 20 of the rotating brush 9 is perpendicular to the surfaces of the film-like positive electrode body, separator, and negative electrode body, and the bristles are provided on a disk. The material of the bristles of the rotating brush may be at least one selected from the group consisting of resin, metal, animal-derived, and plant-derived materials.

[0041] The brush may be toothbrush-shaped, in which case the brush moves back and forth to peel off the fixing part.

[0042] Another preferred peeling unit is a cutting unit. The edge of the separator may be cut by the cutting unit to peel off the edge of the separator. A more preferred cutting unit is an ultrasonic cutter.

[0043] Another preferred peeling unit is a roller. Preferably, the rotation axis of the roller is parallel to the surfaces of the film-like positive electrode body, separator, and negative electrode body, and the roller is brought into contact with the end of the separator to peel off the end of the separator. The material of the roller may be at least one selected from the group consisting of resin, metal, animal-derived, and plant-derived materials. Furthermore, one or more grooves may be formed in the surface of the roller.

[0044] Another preferred peeling unit is a tape peeling agent applicator. When the end of the separator is fixed with tape, the tape peeling agent is applied to the tape by the tape peeling agent applicator, and the end of the separator is peeled off.

[0045] The electrode assembly disassembled in the fifth invention comprises a laminate in which a positive electrode foil, a first separator, a negative electrode foil, and a second separator are stacked in this order, and the terminal ends of the first separator and the second separator are fixed by a fixing means such as tape, adhesive, or crimping. The first separator, positive electrode foil, second separator, and negative electrode foil are all in the form of a film. These are wound, folded, or the like to form a single unit. Figure 10 is a cross-sectional view showing one embodiment of the electrode assembly. The electrode assembly 17 comprises a laminate in which the positive electrode foil 13, the first separator 11, the negative electrode foil 14, and the second separator 12 are stacked in this order. The terminal ends of the first separator 11 and the second separator 14 are fixed.

[0046] In order to peel off the positive electrode foil 13, the first separator 11, the negative electrode foil 14, and the second separator 12 in a second peeling step of a fifth invention described below, it is necessary to peel off the end portions of the first separator 11 and the second separator 12. The disassembling method for a chemical battery of the fifth invention includes a first peeling step of peeling off the ends of the two separators constituting the electrode assembly. The first peeling step of the fifth invention preferably includes a peeling unit insertion step of inserting a peeling unit for the first separator 11 and the second separator 12 into a gap formed between the ends of the first separator 11 and the second separator 12. More preferably, the gap is formed by sucking the first separator 11 and the second separator 12 with a suction unit. The first separator 11 and the second separator 12 are made of resin films, and if they are pinched and peeled off, they may be damaged, making it difficult to peel off the positive electrode foil and the negative electrode foil. When the first separator 11 and the second separator 12 are peeled off by being sucked by a suction unit, damage to the first separator 11 and the second separator 12 is prevented.

[0047] 11 to 13 are explanatory diagrams of one embodiment of the first peeling step. The ends of the first separator 11 and the second separator 12 peeled from the electrode assembly 17 are sucked and pulled by suction units 15a and 15b, respectively. At this point, the terminal ends of the first separator 11 and the second separator 12 are fixed. A gap is immediately formed between the ends of the first separator 11 and the second separator 12 (FIG. 11). The suction units 15a and 15b may be connected to a vacuum pump (not shown) or an ejector. Preferably, the negative electrode foil 14 is positioned above the second separator 12, and the suction force of suction unit 15b sucking the second separator 12 is slightly stronger than the suction force of suction unit 15a sucking the first separator 12. A peeling unit 16 is inserted into the gap and moved (in the direction of the arrow in FIG. 12). Eventually, the pair of the first separator 11 and the positive electrode foil 13 and the pair of the second separator 12 and the negative electrode foil 14 are peeled off ( FIG. 13 ). The portion where the peeling unit 16 contacts the first separator 11 and the second separator 12 may be rod-shaped. The cross-sectional shape of the rod is not limited to a particular shape. The cross-sectional shape may be a circle, an ellipse, a triangle, a rectangle, or a pentagon.

[0048] <Second Peeling Step> The method for disassembling a chemical battery according to the first aspect of the present invention includes a second peeling step (STEP 3 in FIG. 1 ) in which the positive electrode foil, separator, and negative electrode foil constituting the electrode assembly are each peeled off, and the methods for disassembling a chemical battery according to the second to fourth aspects of the present invention may include this second peeling step (STEP 3 in FIG. 1 ). After the adhesive portion is peeled off, the positive electrode foil, separator, and negative electrode foil that have been wound together are each peeled off. The peeled positive electrode foil, separator, and negative electrode foil may each be wound up.

[0049] The disassembly method for a chemical battery according to the fifth aspect of the present invention may include a second peeling step (STEP 3 in FIG. 1 ) in which the first separator 11, the positive electrode foil 13, the second separator 12, and the negative electrode foil 14 constituting the electrode assembly are peeled off. When the ends of the first separator 11 and the second separator 12 are pulled, the first separator 11 and the positive electrode foil 13 are peeled off due to the difference in Young's modulus, and the second separator 12 and the negative electrode foil 14 are also peeled off. FIG. 14 is an explanatory diagram of one embodiment in which the first separator 11, the positive electrode foil 13, the second separator 12, and the negative electrode foil 14 are peeled off. The first separator 11, the positive electrode foil 13, the second separator 12, and the negative electrode foil 14 peeled off in the second peeling step may each be wound up.

[0050] The chemical battery disassembly methods of the first to fifth inventions may include a pulverization step (STEP 4a in FIG. 1 ) of pulverizing the positive electrode foil obtained in the second peeling step. The positive electrode foil powder obtained in the pulverization step may be dissolved in an acid solution and subjected to a step (STEP 4b in FIG. 1 ) of recovering the valuable metals. Furthermore, the positive electrode foil obtained in the second peeling step may be dissolved in an acid solution without being pulverized and subjected to a step (STEP 4b in FIG. 1 ) of recovering the valuable metals. The positive electrode foil obtained from a chemical battery that does not contain an electrolyte, such as a defective product, may be reused as the positive electrode foil for a chemical battery (STEP 4c in FIG. 1 ). The negative electrode foil obtained in the second peeling step may be dissolved in an acid solution without being pulverized and subjected to a step (STEP 4c in FIG. 1 ) of recovering the valuable metals.

[0051] If the positive electrode foil and the negative electrode foil cannot be separated, the positive electrode foil and the negative electrode foil may be roasted, and the remaining components from which carbon has been removed may be dissolved in an acid solution to recover the valuable metals (hereinafter, may be referred to as a valuable metal recovery process).

[0052] The chemical battery disassembly methods of the first to fifth inventions do not include the crushing and sieving steps that conventional methods for recovering valuable metals from discarded lithium-ion batteries include, in which the entire chemical battery is crushed and the resulting crushed material is sieved. Therefore, the chemical battery disassembly method of the present invention does not lose the valuable metals that would have been lost in the crushing and sieving steps. As a result, the chemical battery disassembly method of the present invention contributes to a method for recovering valuable metals from chemical batteries that achieves the recovery rate specified in the Battery Regulations. Furthermore, because the chemical battery disassembly method of the present invention can obtain positive electrode foil powder without a roasting step, the chemical battery disassembly method of the present invention can suppress the generation of carbon dioxide and contribute to reducing environmental impact.

[0053] REFERENCE SIGNS LIST 1...chemical battery, 2...casing, 3...electrode body, 4a...positive electrode terminal plate, 4b...negative electrode terminal plate, 5a...positive electrode side current collector, 5b...negative electrode side current collector, 6...tape, 8...auxiliary unit, 9...rotating brush, 10...projection, 20...rotating shaft, 11...first separator, 12...second separator, 13...positive electrode foil, 14...negative electrode foil, 15...suction unit, 16...peeling unit, 17...electrode body.

Claims

1. A method for disassembling a chemical battery, comprising: an electrode body separation step in which the casing of the chemical battery is cut and the electrode body is removed from inside the casing; a first peeling step in which the fixing portion of the electrode body obtained in the electrode body separation step is peeled off; and a second peeling step in which the positive electrode foil, separator, and negative electrode foil that constitute the electrode body are each peeled off, and the fixing portion of the electrode body is located at the end of the separator.

2. A method for disassembling a chemical battery, the chemical battery comprising a casing, an electrode body, an electrode terminal plate, and a current collector, the electrode body and the electrode terminal plate being electrically connected via the current collector, the method comprising a cutting step of cutting the casing and the current collector.

3. The method for disassembling a chemical battery according to claim 2, wherein the casing is box-shaped and the casing and current collector are cut in a direction perpendicular to the surface on which the electrode terminal plate is attached.

4. The method for disassembling a chemical battery according to claim 3, wherein the cutting location is at least one selected from the group consisting of the positive electrode terminal plate side and the negative electrode terminal plate side.

5. A method for disassembling a chemical battery as described in claim 4, wherein the cutting locations are on the positive electrode terminal plate side and the negative electrode terminal plate side, and cutting is performed in the order of the positive electrode terminal plate side and then the negative electrode terminal plate side, or the negative electrode terminal plate side and then the positive electrode terminal plate side.

6. A method for disassembling a chemical battery, the chemical battery comprising a casing, an electrode body, an electrode terminal plate, and a current collector, the method comprising: a cutting step in which the casing and the current collector are cut; and an electrode body separation step in which the electrode body is pushed out by an auxiliary unit.

7. The method for disassembling an electrochemical battery according to claim 6, further comprising a step of perforating the casing.

8. A method for disassembling a chemical battery as described in claim 7, wherein the casing is box-shaped, the end of the casing and the current collector are cut in a direction perpendicular to the surface on which the electrode terminal plate is attached in the cutting step, and the end of the casing opposite to the end cut in the cutting step is perforated in the perforating step.

9. The method for disassembling a chemical battery according to claim 8, wherein the casing and current collector on the negative terminal plate side are cut in the cutting step.

10. A method for disassembling a chemical battery, comprising a first peeling step in which an end of an electrode body is peeled off and opened, the electrode body being configured by winding a positive electrode foil and a negative electrode foil with a separator interposed therebetween, and the end of the separator being fixed.

11. A method for disassembling an electrochemical battery according to claim 10, wherein a brush is brought into contact with the end of the separator fixed with an adhesive material, and the end of the separator is peeled off.

12. The method for disassembling an electrochemical battery according to claim 11, wherein the brush is rotating.

13. A method for disassembling a chemical battery as described in claim 11, wherein the brush has a structure in which spiral projections are formed on a shaft and bristles are provided on the projections.

14. A method for disassembling a chemical battery, comprising a first peeling step of peeling off the ends of two separators that constitute an electrode body, the electrode body comprising a laminate in which a positive electrode foil, a first separator, a negative electrode foil, and a second separator are stacked in this order, and the end portions of the first separator and the second separator are fixed.

15. A method for disassembling a chemical battery according to claim 14, wherein the first peeling step includes a peeling unit insertion step in which, after a gap is formed between the ends of the first separator and the second separator, peeling units for the first separator and the second separator are inserted into the gap.

16. The method for disassembling an electrochemical battery according to claim 15, wherein the first separator and the second separator are sucked by a suction unit to form the gap.

17. The method for disassembling an electrochemical battery according to claim 15, wherein the peeling unit comprises a rod.

18. A method for disassembling a chemical battery according to any one of claims 1 to 17, wherein the chemical battery is a secondary battery.

19. The method for disassembling a chemical battery according to claim 18, wherein the secondary battery is a lithium ion battery.

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