Method for processing lithium ion secondary battery

Abstract

To stably separate, from a lithium ion secondary battery, molten metal such as aluminum, and a non-melting material.SOLUTION: There is provided a method for processing a lithium ion secondary battery, in which a lithium ion secondary battery including metal that melts at temperatures of 650°C or above and 1,000°C or below is subjected to incineration at temperatures higher than the melting point of the metal. The method includes the steps of: arranging a plurality of the lithium ion secondary batteries, in a container having a plurality of holes in the bottom thereof; subjecting the lithium ion secondary battery to incineration to separate, from the holes to the outside of the container, molten metal that flows out of the lithium ion secondary battery; and recovering a battery material, from which the molten metal has been separated, from inside the container. In the step of arranging the lithium ion secondary batteries, the lithium ion secondary batteries are arranged such that terminals of the lithium ion secondary batteries do not come into contact with each other.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for treating a lithium-ion secondary battery.

Background Art

[0002] A method of incinerating a used lithium-ion secondary battery and separating and recovering valuable materials is known. For example, Patent Document 1 discloses a recovery container for molten metal used in an incinerator for incinerating a lithium-ion secondary battery containing a metal that melts at 700°C to 1000°C at a temperature higher than the melting point of the metal. The lithium-ion secondary battery is placed thereon, and the recovery container has a shape for receiving the molten metal flowing out of the lithium-ion secondary battery. The inner surface of the recovery container is a sticking suppression surface for suppressing the sticking of the molten metal, and a support portion for supporting the lithium-ion secondary battery at a position higher than the inner surface of the bottom of the recovery container and a storage portion for storing the molten metal are formed. A support member for the lithium-ion secondary battery protruding upward from the inner surface of the bottom of the recovery container is provided.

[0003] Also, for example, Patent Document 2 discloses a method for recovering valuable materials from a lithium-ion battery, including a melting separation step of heating a waste lithium-ion battery using at least an aluminum material as a constituent material of a battery case at a temperature of 660°C or higher to melt the aluminum material, and separating the molten aluminum material from the non-molten material constituting the battery main body, and a pulverization step of pulverizing the non-molten material obtained in the melting separation step to obtain a pulverized product. In the melting separation step, the waste lithium-ion battery placed on a net-like body is heated at a temperature of 660°C or higher to melt the aluminum material and let it fall through the meshes of the net-like body, and the non-molten material constituting the battery main body is left on the net-like body, thereby separating the molten aluminum material from the non-molten material.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Patent Application Laid-Open No. 2021-138996 Patent Document 2 Japanese Patent No. 6268130 Summary of the Invention Problems to be Solved by the Invention

[0005] One embodiment of the present invention aims to stably separate molten metal such as aluminum and non-molten materials from a lithium-ion secondary battery. Means for Solving the Problems

[0006] The first aspect of the present invention is A method for treating a lithium-ion secondary battery, which includes subjecting a lithium-ion secondary battery containing a metal that melts at 650°C or higher and 1000°C or lower to a calcination treatment at a temperature higher than the melting point of the metal, a step of arranging a plurality of lithium-ion secondary batteries in a container having a plurality of holes at the bottom, a step of subjecting the lithium-ion secondary battery to a calcination treatment and separating the molten metal flowing out from the lithium-ion secondary battery from the holes to the outside of the container, and a step of recovering the battery material from which the molten metal has been separated from the inside of the container, and in the step of arranging the lithium-ion secondary batteries, the lithium-ion secondary batteries are arranged so that the terminals of the lithium-ion secondary batteries do not contact each other. This is a method for treating a lithium-ion secondary battery.

[0007] The second aspect of the present invention is In the step of arranging the lithium-ion secondary batteries, the lithium-ion secondary batteries are arranged with their terminals facing upward. This is the method for treating a lithium-ion secondary battery according to the first aspect described above.

[0008] The third aspect of the present invention is In the step of arranging the lithium-ion secondary battery, the lithium-ion secondary batteries are arranged horizontally without stacking the lithium-ion secondary batteries in the depth direction of the container, which is the method for treating a lithium-ion secondary battery according to the first aspect described above.

[0009] A fourth aspect of the present invention is stacking and fixing a plurality of the containers in which the lithium-ion secondary batteries are arranged, and subjecting them to the incineration treatment, which is the method for treating a lithium-ion secondary battery according to the first aspect described above.

[0010] A fifth aspect of the present invention is the container has an inclined portion in which at least one surface of the side surface is inclined toward the outside of the container, in the step of recovering the battery material from the container, the container is tilted, and the battery material is recovered from the container through the inclined portion, which is the method for treating a lithium-ion secondary battery according to the first aspect described above.

[0011] A sixth aspect of the present invention is in the step of arranging the lithium-ion secondary battery, when the height of the lithium-ion secondary battery is h, the lithium-ion secondary battery is arranged in the container having a depth greater than h and less than 2h, which is the method for treating a lithium-ion secondary battery according to the first aspect described above.

Advantages of the Invention

[0012] According to an embodiment of the present invention, a molten metal such as aluminum and a non-molten material can be stably separated from the lithium-ion secondary battery.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] <Findings Obtained by the Inventor> First, the findings obtained by the inventor will be described.

[0015] For example, when a lithium ion secondary battery is placed in a container as described in Patent Document 1 and incineration treatment is performed, there is a problem that a large amount of other battery materials are mixed into the molten metal such as aluminum, making it difficult to separate them.

[0016] Also, for example, when a certain amount or more of lithium ion secondary batteries are placed on a net-like body as described in Patent Document 2 and incineration treatment is performed, when using the net-like body, since the strength of the net-like body is low, the posture of the lithium ion secondary battery is likely to become unstable during the incineration treatment, and the terminals may come into contact with conductive materials (such as containers), causing a short circuit and the risk of sudden heat generation and ignition. Also, the efficiency of recovering the non-molten materials remaining on the net-like body is not considered.

[0017] The inventors have conducted intensive studies on the above problems. As a result, a process of arranging a plurality of lithium-ion secondary batteries in a container having a plurality of holes at the bottom, a process of incinerating the lithium-ion secondary batteries, and separating the molten metal flowing out from the lithium-ion secondary batteries to the outside of the container through the holes, and a process of recovering the battery material from which the molten metal has been separated from the container are performed. In the process of arranging the lithium-ion secondary batteries, it has been found that the lithium-ion secondary batteries can be stably incinerated by arranging a plurality of lithium-ion secondary batteries so that the terminals of the lithium-ion secondary batteries do not contact each other. According to the above processing method, the molten metal such as aluminum and the non-molten material can be stably separated. In addition, the generation of sudden heat generation and ignition due to terminal contact can be prevented during storage and transportation before incineration and when charging into the heating furnace.

[0018] [Details of Embodiments of the Present Invention] Next, an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to these examples, and is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0019] In this specification, "A to B" means a numerical range of "A or more and B or less".

[0020] [First Embodiment of the Present Invention] (1) Processing Container for Lithium-Ion Secondary Battery First, the processing container 10 for lithium-ion secondary batteries (hereinafter, also simply referred to as the container 10) used in this embodiment will be described. As shown in FIGS. 1(a), (b), 2, and 4, the container 10 houses a lithium-ion secondary battery 20 containing a metal that melts at 650°C or higher and 1000°C or lower, such as aluminum (hereinafter, also referred to as molten metal), and is used when performing incineration treatment at a temperature higher than the melting point of the molten metal. Considering the heating temperature of the incineration treatment, the material of the container 10 is preferably SUS304, for example. FIGS. 1(a) and (b) are schematic views showing an example of the container 10 used in this embodiment, FIG. 1(a) is a plan view seen from above, and FIG. 1(b) is a side view.

[0021] As shown in Fig. 1(a), the container 10 has a plurality of holes 11 at the bottom. The plurality of holes 11 are holes for separating the molten metal flowing out from the lithium-ion secondary battery 20 during the incineration process outside the container 10. Thereby, the separation between the molten metal such as aluminum and other battery materials can be stably performed.

[0022] The shape and number of the holes 11 do not matter as long as they can sufficiently collect the molten metal such as aluminum and maintain the required bottom strength, but the size of the holes is preferably such that a sphere with a diameter of 10 mm can pass through. For example, it can be an elliptical slit shape, with a length of 50 to 200 mm and a width of 10 to 30 mm. As shown in Fig. 1(a), it is preferable that the plurality of holes 11 have slits extending in the long side direction of the container 10 and are arranged at predetermined intervals. The material, thickness, shape, and number of the holes at the bottom are preferably such that they can maintain the bottom strength so that the posture of the lithium-ion secondary battery does not become unstable before the lithium-ion secondary battery is deactivated during the incineration process.

[0023] The depth d of the container 10 is preferably, for example, 50 mm or more and 400 mm or less. When assuming that the height of the lithium-ion secondary battery 20 (for example, plate-shaped) to be processed is 210 mm, the above numerical range is set to a depth at which the lithium-ion secondary battery 20 can be stacked in one layer and cannot be stacked in two layers (if stacked in two layers, the lithium-ion secondary battery 20 will protrude from the container 10). Thereby, the contact between the terminals 21 of the lithium-ion secondary battery 20 can be suppressed. Note that, as shown in Fig. 1(b), when a recess 14 is provided on the side surface, the depth d of the container 10 indicates the depth of the portion where the recess 14 is provided (in other words, the minimum value of the depth of the container 10).

[0024] As shown in FIG. 1(b), the container 10 preferably has an inclined portion 12 at least one side surface of which is inclined outward of the container. Thereby, when collecting the battery material from which the molten metal has been separated from the inside of the container 10, by tilting the container 10, the battery material can be easily collected from the inside of the container 10 from the inclined portion 12.

[0025] The inclination angle θ (see FIG. 1(b)) of the inclined portion 12 is preferably, for example, 30 degrees or more and 45 degrees or less. If the inclination angle θ is less than 30 degrees, it may be difficult to collect the battery material. On the other hand, by setting the inclination angle θ to 30 degrees or more, it becomes easier to collect the battery material. On the other hand, if the inclination angle θ exceeds 45 degrees, the number of lithium-ion secondary batteries 20 that can be arranged in the container 10 decreases with respect to the total length of the container 10, and the processing efficiency may decrease (because it is not suitable to arrange the lithium-ion secondary battery 20 on the inclined surface as the posture is not stable). On the other hand, by setting the inclination angle θ to 45 degrees or less, the processing efficiency of the lithium-ion secondary battery 20 can be maintained.

[0026] The total area of the plurality of holes 11 is preferably 50% or less of the bottom area of the container 10, and more preferably 10% or more and 40% or less. If the total area of the plurality of holes 11 is less than 10% of the bottom area, it may be difficult to separate the molten metal outside the container 10. On the other hand, by setting the total area of the plurality of holes 11 to 10% or more of the bottom area, it becomes easier to separate the molten metal outside the container 10. On the other hand, if the total area of the plurality of holes 11 exceeds 40% of the bottom area, the strength of the container 10 may decrease. Also, during storage and transportation and when loading into the heating furnace, the posture of the lithium-ion secondary battery 20 becomes unstable, the terminals 21 of the lithium-ion secondary battery 20 may come into contact, and there is a risk of causing a fire due to a short circuit. On the other hand, by setting the total area of the plurality of holes 11 to 40% or less of the bottom area, the posture of the lithium-ion secondary battery 20 can be stabilized, the contact of the terminals 21 during storage, transportation, and when loading into the heating furnace can be suppressed, and the strength of the container 10 during the incineration process can be maintained. Note that the bottom area of the container 10 refers to the area of the flat portion excluding the inclined surfaces such as the inclined portion 12.

[0027] As shown in Fig. 1(b), a plurality (two in this embodiment) of cylindrical support portions 13 are provided on the outer side of the bottom surface of the container 10. The support portion 13 serves as, for example, a fork pocket when transporting the container 10 with a forklift or the like. Thereby, the container 10 can be easily transported. Further, as shown in Fig. 1(a), it is preferable that the plurality of holes 11 are arranged avoiding the portions where the support portions 13 are provided.

[0028] As shown in Fig. 1(a), in a plan view seen from above, when the plurality of holes 11 are in a slit shape, it is preferable that the longitudinal direction thereof intersects (or is orthogonal to) the longitudinal direction of the support portion 13. In other words, it is preferable that the intersection of the longitudinal direction of the plurality of holes 11 and the longitudinal direction of the support portion 13 exists on the bottom surface. Thereby, the strength of the container 10 can be improved. Further, since deformation of the container 10 during the incineration process is suppressed, the container 10 can be easily reused.

[0029] As shown in Fig. 1(a), in a plan view seen from above, it is preferable that the direction in which the inclined portion 12 is inclined and the longitudinal direction of the support portion 13 are orthogonal (or intersect). In other words, it is preferable that the intersection of the direction in which the inclined portion 12 is inclined and the longitudinal direction of the support portion 13 exists on the bottom surface. Thereby, even when the container 10 is tilted in the direction in which the inclined portion 12 is inclined with a forklift or the like, it is possible to prevent the fork from coming off.

[0030] As shown in Fig. 1(a), in a plan view seen from above, it is preferable that the longitudinal direction of the plurality of holes 11 and the direction in which the inclined portion 12 is inclined are substantially parallel (or coincide). In this specification, substantially parallel includes not only being completely parallel but also including cases where there is a deviation of 10° or less from parallel.

[0031] As shown in Fig. 1(b), it is preferable to provide a detachable lid 15 on the upper surface of the container 10. Thereby, oxidation of non-molten metals such as black mass remaining in the container can be suppressed.

[0032] FIG. 2 is a schematic view showing a state in which a plurality of containers 10 are stacked and fixed. As shown in FIG. 2, a plurality of recesses 14 can be provided on the upper side of the side surface of the container 10. When a plurality of containers 10 are stacked, it is preferable that the support portion 13 of the upper container 10a and the recess 14 of the lower container 10b are fitted together. Thereby, it becomes possible to collectively incinerate a large number of lithium-ion secondary batteries 20 without stacking the lithium-ion secondary batteries 20 in one container 10. Further, as shown in FIG. 2, since the bottom of the upper container 10a serves as a lid for the lower container 10b, the oxidative combustion during incineration can be appropriately controlled without providing a lid 15 on the lower container 10b. Incidentally, as shown in FIG. 2, it is preferable to provide a lid 15 on the upper surface of the uppermost container (container 10a in FIG. 2). Further, when stacking the containers 10, a guide (not shown) may be provided on the side surface or the like so that positioning is easy.

[0033] As shown in FIG. 1(b) and FIG. 2, it is preferable that the lid 15 is also provided with the support portion 13. Further, as shown in FIG. 2, the lid 15 can also be used as a tray for molten metal such as aluminum by being installed, for example, below the lower container 10b.

[0034] It is preferable that, for example, alumina is coated on the inner wall (inside the side surface and inside the bottom surface) of the container 10. Thereby, it is possible to suppress the molten metal from staying in the container 10 for a long time, and to suppress the deterioration and deformation of the container 10.

[0035] (2) Method for treating lithium-ion secondary battery Next, a method for treating a lithium-ion secondary battery according to this embodiment will be described. The lithium-ion secondary battery 20 contains a metal (molten metal) that melts at 650°C or higher and 1000°C or lower, such as aluminum. The method for treating a lithium-ion secondary battery according to this embodiment is a treatment method in which incineration is performed at a temperature higher than the melting point of the molten metal such as aluminum. FIG. 3 is a flowchart showing an example of the method for treating a lithium-ion secondary battery according to this embodiment. The incineration treatment is preferably at 700°C or higher and 1000°C or lower, and more preferably at 750°C or higher and 900°C or lower. As shown in FIG. 3, the method for treating a lithium-ion secondary battery according to this embodiment has, for example, an arrangement step S101, an incineration step S102, and a recovery step S103.

[0036] (Arrangement step S101) The arrangement step S101 is, for example, a step of arranging a plurality of lithium-ion secondary batteries 20 in a container 10 having a plurality of holes 11 at the bottom. FIG. 4 is a schematic diagram showing an example of a case where a plurality of lithium-ion secondary batteries 20 (for example, plate-shaped) are arranged in the container 10.

[0037] In the arrangement step S101, a plurality of lithium-ion secondary batteries 20 are arranged so that the terminals 21 of the lithium-ion secondary batteries 20 do not contact each other. When the shape of the lithium-ion secondary battery 20 is a shape that is likely to fall when arranged, it is preferable to make an arrangement that is not likely to fall, for example, by narrowing the interval between the lithium-ion secondary batteries. Thereby, the posture of the lithium-ion secondary battery 20 can be stabilized, contact of the terminals 21 during storage and transportation and when being introduced into the heating furnace can be suppressed, and the strength of the container 10 during the incineration treatment can be maintained.

[0038] In the arrangement step S101, for example, as shown in FIG. 4, it is preferable to arrange the terminals 21 of the lithium-ion secondary batteries 20 facing upward. Thereby, since it becomes difficult for the terminals 21 to contact the container 10, the lithium-ion secondary battery 20 can be stably incinerated.

[0039] In the arrangement step S101, for example, it is preferable to arrange a plurality of lithium-ion secondary batteries 20 horizontally without stacking the lithium-ion secondary batteries 20 in the depth direction of the container 10. That is, as shown in FIG. 4, it is preferable to arrange a plurality of lithium-ion secondary batteries 20 with the directions in which the terminals 21 of the lithium-ion secondary batteries 20 face aligned upward. Thereby, it is possible to suppress the terminals 21 of the lithium-ion secondary batteries 20 from coming into contact with each other and causing rapid combustion.

[0040] In the arrangement step S101, for example, when the height of the lithium-ion secondary battery 20 to be processed is h, it is preferable to prepare a container 10 having a depth greater than h and less than 2h and arrange the lithium-ion secondary battery 20 therein. Thereby, since a container 10 that enables stacking of the lithium-ion secondary batteries 20 in one layer and does not enable stacking in two layers is used, it is possible to suppress the terminals 21 of the lithium-ion secondary batteries 20 from coming into contact with each other and causing rapid combustion.

[0041] In the arrangement step S101, for example, as shown in FIG. 2, it is preferable to stack and fix a plurality (two layers in FIG. 2) of containers 10 in which the lithium-ion secondary batteries 20 are arranged and subject them to incineration treatment. Thereby, it becomes possible to collectively incinerate a large number of lithium-ion secondary batteries 20 without stacking the lithium-ion secondary batteries 20 in one container 10. Further, as shown in FIG. 2, since the bottom and the lid 15 of the upper container 10a serve as the lid of the lower container 10b, it is possible to appropriately control the oxidative combustion during the incineration treatment without providing the lid 15 on the lower container 10b. Note that, as shown in FIG. 2, it is preferable to provide the lid 15 on the upper surface of the uppermost container (container 10a in FIG. 2).

[0042] In the arrangement step S101, for example, as shown in FIG. 4, after placing the lithium-ion secondary battery 20 in the container 10, it is preferable to provide a lid 15 on the upper surface of the container 10. Thereby, oxidation of the lithium-ion secondary battery 20 during the incineration process can be appropriately suppressed. Further, it is preferable to provide a support portion 13 having the same shape as the support portion 13 provided in the container 10 below the lid 15. In this case, the support portion 13 can be used when moving the lid 15 alone. Further, in a state where the upper portion of the container 10 is closed by the lid 15, the support portion 13 of the lid 15 is fitted into the concave portion 14 of the container 10, so that not only oxidation suppression of the battery but also deformation of the lid 15 and the container 10 due to heat during incineration can be suppressed. Furthermore, by providing side walls around the lid 15 to form a tray shape, the container 10 can also be stacked on the lid 15. In this case, the molten metal can be stored and recovered on the upper surface of the lid 15. Further, in order to improve the convenience during metal recovery, unevenness for forming an ingot may be provided on the upper surface of the lid 15.

[0043] (Incineration step S102) The incineration step S102 is, for example, a step of incinerating the lithium-ion secondary battery 20 and separating the molten metal flowing out from the lithium-ion secondary battery 20 to the outside of the container 10 through the hole 11. For the incineration treatment, a known heating furnace or the like can be used. The separated molten metal may be, for example, collected after arranging another recovery container below the container 10 after the incineration treatment. In the arrangement step S101, when a plurality of containers 10 are stacked and fixed, in the incineration step S102, it is preferable to incinerate the plurality of containers 10 together in a stacked state. Even in this case, since the molten metal flows out from the upper container 10a to the lower container 10b and is finally separated outside the container 10, the processing efficiency of the lithium-ion secondary battery 20 can be improved.

[0044] In the incineration step S102, for example, it is preferable to incinerate the lithium-ion secondary battery 20 in a reducing atmosphere. Thereby, oxidation of various metals contained in the lithium-ion secondary battery 20 can be suppressed. From this viewpoint, it is preferable to use the stacking of the containers 10 and the lid 15.

[0045] (Recovery Step S103) In the recovery step S103, for example, after incineration treatment, the container 10 is carried out of the heating furnace, and a battery material (such as a metal material other than the molten metal contained in the lithium-ion secondary battery 20) from which the molten metal has been separated is recovered from inside the container 10.

[0046] When the container 10 has the inclined portion 12, in the recovery step S103, it is preferable to tilt the container 10 and recover the battery material from inside the container 10 from the inclined portion 12. Thereby, the battery material can be recovered simply. At this time, if a member such as a fork of a forklift is inserted into the support portion 13 and the member is moved to tilt the container 10, the battery material can be efficiently recovered.

[0047] By the above steps, the lithium-ion secondary battery 20 can be stably incinerated. Specifically, the lithium-ion secondary battery 20 can be incinerated, and the separation of the molten metal such as aluminum and other battery materials can be stably performed.

[0048] <Other Embodiments of the Present Invention> Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

[0049] For example, in the above-described embodiment, as shown in FIG. 1(b), the case where the inclined portion 12 is provided only on one side of the container 10 has been described. However, the inclined portion 12 may be provided on both sides of the container 10. In this case, in the recovery step S103, when tilting the container 10 to recover the battery material from inside the container 10, the degree of freedom in the tilting direction increases. However, from the viewpoint of maintaining the processing efficiency, since the number of lithium-ion secondary batteries 20 that can be arranged inside the container 10 decreases with respect to the total length of the container 10 and the processing efficiency may decrease, it is preferable to provide the inclined portion 12 only on one side of the container 10 as in the above-described embodiment.

[0050] Further, for example, in the above-described embodiment, as shown in FIG. 2, the case where the containers 10 are stacked and fixed in two stages has been described. However, in the arrangement step S101, the containers 10 may be stacked and fixed in three or more stages. In this case, more lithium ion secondary batteries 20 can be processed at once. Note that the upper limit of the number of stages of the stacked containers 10 is preferably, for example, five stages or less so that the total weight does not become too large.

Example

[0051] Next, examples according to the present invention will be described. These examples are examples of the present invention, and the present invention is not limited by these examples.

[0052] (Example 1) In Example 1, as shown in FIG. 1, a SUS304 container 10 having a depth of 250 mm, a length of 1630 mm, and a width of 920 mm, with a slit-shaped hole having a size of 100 mm in length and 20 mm in width and an inclined portion of about 40° was used to perform incineration treatment on a lithium ion secondary battery 20 (height 170 mm, longitudinal width 25 mm, lateral width 100 mm). First, the lithium ion secondary batteries 20 with a total weight of 360 kg were divided into two and placed in each of the two containers 10. Specifically, 30 batteries were vertically packed without gaps in the width direction of one container 10 so that the terminals were on the upper surface, and arranged in 6 rows in the length direction. The two containers 10 were stacked in two stages, and the support portion 13 of the second-stage container 10 was fitted into the recess 14 of the first-stage container 10 and fixed. Further, the second-stage container 10 was covered with a lid 15.

[0053] Next, the two-stage stacked containers 10 were carried into a heating furnace and incinerated at 850° C. for 4 hours under reduced pressure. The molten metal (aluminum) flowing out from the lithium ion secondary battery 20 separated outside the container 10 through the plurality of holes 11 and was collected in a recovery container arranged below the container 10.

[0054] After incineration, the container 10 and the recovery container were each removed from the heating furnace. The fork of the forklift was inserted into the support portion 13 to lift the container 10, and then the container 10 was tilted to quickly and efficiently recover the battery material. The weight of the recovered battery material was 259.2 kg, and the weight of the aluminum recovered in the recovery container was 100.8 kg. It was confirmed that the aluminum was cleanly separated. Also, it was confirmed that the container 10 after incineration was not deformed. Further, no sudden heat generation or ignition occurred in the heating furnace during incineration.

[0055] (Comparative Example 1) In Comparative Example 1, as shown in Fig. 5(a), a box-shaped container 100 (with a lid) without a plurality of holes 11 or inclined portions 12 was used. A support member similar to that in Example 1 of Patent Document 1 (see Fig. 6 of Patent Document 1) was provided at the bottom of the container 100, and the same amount of lithium-ion secondary batteries 20 as in Example 1 were put into one container 100 for incineration treatment. The conditions of the incineration treatment were the same as those in Example 1.

[0056] After incineration treatment, when the inside of the container 100 was checked, although some aluminum was separated at the bottom below the support member, there was also a lot of contamination of the battery material. As shown in Fig. 5(b), the aluminum 101 and the battery material 102 were not sufficiently separated. Also, it was confirmed that the container 100 was deformed and a part of the lithium-ion secondary battery 20 had scattered outside the container 100.

[0057] From the above, by using the treatment method which is an embodiment of the present invention, only aluminum, which is a molten metal, flowed out of the container, and the other non-molten battery materials (especially black mass) remained inside the container. Also, during incineration, the posture of the lithium-ion secondary battery became stable and no sudden heat generation or ignition due to short circuit occurred.

Explanation of Reference Numerals

[0058] 10, 10a, 10b Containers (treatment containers) 11 Holes 12 Inclined portions 13 Support portion 14 Concave part 15 Lid 20 Lithium-ion secondary battery 21 Terminal 100 Container 101 Aluminum 102 Battery material S101 Placement process S102 Incineration process S103 Recovery process

Claims

1. A method for treating a lithium-ion secondary battery, which includes a metal that melts at a temperature of 650 °C or higher and 1000 °C or lower, and which comprises subjecting the lithium-ion secondary battery to incineration treatment at a temperature higher than the melting point of the metal, the step of arranging a plurality of lithium-ion secondary batteries in a container having a plurality of holes at the bottom, the step of subjecting the lithium-ion secondary battery to incineration treatment and separating the molten metal flowing out from the lithium-ion secondary battery from the holes to the outside of the container, and the step of recovering the battery material from which the molten metal has been separated from inside the container, wherein, in the step of arranging the lithium-ion secondary batteries, the plurality of lithium-ion secondary batteries are arranged so that the terminals of the lithium-ion secondary batteries do not contact each other. A method for treating a lithium-ion secondary battery.

2. The method for treating a lithium-ion secondary battery according to claim 1, wherein, in the step of arranging the lithium-ion secondary batteries, the terminals of the lithium-ion secondary batteries are arranged in an upward direction.

3. The method for treating a lithium-ion secondary battery according to claim 1, wherein, in the step of arranging the lithium-ion secondary batteries, the plurality of lithium-ion secondary batteries are arranged horizontally without stacking the lithium-ion secondary batteries in the depth direction of the container.

4. The method for treating a lithium-ion secondary battery according to claim 1, wherein a plurality of the containers in which the lithium-ion secondary batteries are arranged are stacked and fixed and subjected to the incineration treatment.

5. The container has an inclined portion in which at least one side surface is inclined toward the outside of the container, and in the step of recovering the battery material from inside the container, the container is tilted and the battery material is recovered from inside the container through the inclined portion. The method for treating a lithium-ion secondary battery according to claim 1.

6. The method for treating a lithium-ion secondary battery according to claim 1, wherein, in the step of arranging the lithium-ion secondary batteries, when the height of the lithium-ion secondary battery is h, the lithium-ion secondary battery is arranged in the container having a depth of more than h and less than 2h.

Images