Methods for destroying secondary batteries

Abstract

This invention provides a safe and simple method for destroying secondary batteries. [Solution] A method for destroying a secondary battery, comprising: a preparation step (S1) of preparing a housing in which a secondary battery is disposed and oil is stored so that at least a portion of the secondary battery is submerged; and a battery destruction step (S3) after the preparation step (S1), destroying at least the portion of the secondary battery that is submerged in the oil while the secondary battery is submerged in the oil.

Description

Technical Field

[0001] The present invention relates to a method for destroying secondary batteries.

Background Art

[0002] Secondary batteries, particularly lithium-ion batteries, have become widespread from the viewpoints of high energy density and long life. However, due to their high energy density, explosion and fire accidents occur when improper disposal is carried out, which has become a social problem.

[0003] Currently, used lithium-ion batteries are collected by local governments, electronics stores, etc., and specialized operators perform discharge treatment manually. After that, through crushing and incineration, the metal components used in the electrodes are recovered. There is always a risk of explosion and fire in these processes, and the development of a safe treatment method is desired.

[0004] Patent Document 1 discloses a method for treating a secondary battery containing metallic lithium in a negative electrode, including a steam contact step of bringing steam at 40 - 175°C into contact with a battery cell.

[0005] Patent Document 2 discloses a method for treating battery waste, including a first heat treatment step of heating the battery waste in an atmosphere containing at least one selected from the group consisting of nitrogen, carbon dioxide, and steam, and a second heat treatment step of heating the battery waste in an atmosphere different from the atmosphere in the first heat treatment step and containing a larger amount of oxygen than the first heat treatment step after switching from the atmosphere in the first heat treatment step.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

[0007] However, the conventional technology described above has the following problems. In the secondary battery processing method disclosed in Patent Document 1, metallic lithium is brought into contact with water vapor, causing the metallic lithium and water to react and produce lithium hydroxide. This reaction can reduce (deactivate) the reactivity of lithium. However, since metallic lithium and water react violently, it is not easy to control the reaction.

[0008] Furthermore, the battery waste treatment method disclosed in Patent Document 2 requires special equipment because the first heat treatment step is carried out under an inert gas while adjusting the oxygen partial pressure.

[0009] One aspect of the present invention aims to provide a safe and simple method for destroying a secondary battery. [Means for solving the problem]

[0010] As a result of diligent research to solve the above problems, the inventors of the present invention have discovered for the first time that by destroying a secondary battery while at least a portion of it is immersed in oil, it is possible to suppress the temperature rise caused by the oil, block the intrusion of air and water into the secondary battery by the oil, and detoxify the electrolyte by allowing it to flow into the oil, thereby enabling the safe destruction of the secondary battery, and have completed the present invention.

[0011] In other words, in order to solve the above problems, a method for destroying a secondary battery according to one aspect of the present invention includes a preparation step of preparing a housing in which a secondary battery is disposed and in which oil is stored so as to immerse at least a portion of the secondary battery, and a battery destruction step of destroying at least the portion of the secondary battery that is immersed in the oil, while the secondary battery is immersed in the oil after the preparation step. [Effects of the Invention]

[0012] According to one aspect of the present invention, a method for safely and easily destroying a secondary battery can be provided. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing an example of the configuration of a housing that can be used in the secondary battery destruction method according to Embodiment 1 of the present invention. [Figure 2] This is a flowchart showing the flow of a method for destroying a secondary battery according to Embodiment 1 of the present invention. [Figure 3] This is a flowchart showing the flow of a method for destroying a secondary battery according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0014] One aspect of the present invention will be described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "greater than or equal to A and less than or equal to B".

[0015] [Methods for destroying rechargeable batteries] A method for destroying a secondary battery according to one aspect of the present invention includes a preparation step of preparing a housing in which a secondary battery is disposed and in which oil is stored so as to immerse at least a portion of the secondary battery, and a battery destruction step of destroying at least the portion of the secondary battery immersed in the oil, while the secondary battery is immersed in the oil after the preparation step.

[0016] According to one aspect of the present invention, the method for destroying a secondary battery includes the battery destruction step described above, and therefore the secondary battery can be destroyed safely and easily. More specifically, in the method for destroying a secondary battery according to one aspect of the present invention, at least a portion of the secondary battery is immersed in oil during the battery destruction step, and at least the portion of the secondary battery immersed in the oil is destroyed. As a result, when the outer casing of the secondary battery is destroyed, the oil can block air, which is a source of oxygen, and water, which is a source of hydrogen and can cause thermal runaway, from entering the inside of the battery. Furthermore, as a result of the battery destruction, the electrolyte, which can cause a short circuit in the battery, flows into the oil, so the electrolyte can be safely rendered harmless without coming into contact with air and water. In addition, as oil flows into the inside of the secondary battery from the destroyed part of the outer casing, the electrodes inside the secondary battery are immersed in oil, so the reaction between the electrodes and air and water can be prevented. Moreover, even if a short circuit occurs, the cooling effect of the oil prevents the temperature of the secondary battery from rising beyond a specified temperature (e.g., 80°C, 200°C, etc.), thus preventing overheating. According to one aspect of the present invention, a method for destroying a secondary battery allows for safe disposal of the secondary battery while preventing heat generation, even when post-processing such as incineration or electrode removal is performed after the battery destruction process.

[0017] Furthermore, before destroying a secondary battery, a discharge process is usually required to discharge any remaining electricity from it. This is because if a secondary battery is destroyed without performing the discharge process, or if the discharge process is performed but the discharge is insufficient, there is a risk of the secondary battery igniting and exploding. The discharge process requires integrating each secondary battery into the circuit and discharging it one by one, which is a costly and time-consuming process.

[0018] In contrast, since the method for destroying a secondary battery according to one aspect of the present invention includes the battery destruction step described above, it is possible to destroy the secondary battery without discharging. Therefore, the method for destroying a secondary battery according to one aspect of the present invention may not include a discharging step before the battery destruction step, or a discharging step may be provided before the battery destruction step. However, even if not all are completely discharged, the battery destruction step can be performed. This leads to a significant reduction in the processing cost and processing time involved in destroying the secondary battery.

[0019] <Secondary battery> In this specification, "secondary battery" means a battery that can be charged and discharged. The specific type of secondary battery targeted by the method for destroying a secondary battery according to one aspect of the present invention is not particularly limited. The method for destroying a secondary battery according to one aspect of the present invention can be applied to conventionally known secondary batteries, and examples include lead-acid batteries, lithium-ion batteries, nickel-cadmium batteries, nickel-metal hydride batteries, sodium-ion batteries, etc., and it can be particularly preferably applied to lithium-ion batteries.

[0020] Also, as lithium-ion batteries, there are liquid-type lithium-ion secondary batteries using an electrolyte solution (organic solvent + lithium salt); lithium-ion polymer secondary batteries using a polymer electrolyte instead of the electrolyte solution; solid electrolyte-type lithium-ion secondary batteries using a solid electrolyte instead of the electrolyte solution, etc. These can be targeted by the method for destroying a secondary battery according to one aspect of the present invention. The method for destroying a secondary battery according to one aspect of the present invention can be particularly preferably applied to liquid-type lithium-ion secondary batteries and lithium-ion polymer secondary batteries, and among these, it can be more preferably applied to liquid-type lithium-ion secondary batteries.

[0021] The structure of the secondary battery is not particularly limited. For example, in the case of a lithium-ion battery, usually, a positive electrode, a negative electrode, and a separator provided as necessary are wound in a flat spiral shape to form a wound electrode plate group, or these are made into a flat plate shape and laminated to form a laminated electrode plate group, and these electrode plate groups are generally enclosed in an outer package.

[0022] <Enclosure> The configuration of a housing that can be used in a secondary battery destruction method according to one aspect of the present invention will be described with reference to Figure 1. Figure 1 is a perspective view showing an example of the configuration of a housing 1 that can be used in a secondary battery destruction method according to one aspect of the present invention. In Figure 1, a secondary battery 2 is placed inside the main body 11 of the housing 1, and oil 3 is stored so that the entire secondary battery 2 is submerged.

[0023] The housing 1 comprises a box-shaped main body 11, a lid 12 that closes the top opening of the main body 11, and an oil drain port 13. A secondary battery 2 is placed inside the main body 11, and oil 3 is stored inside. The size of the main body 11 is not particularly limited, as long as it has sufficient space (bottom area) to accommodate the secondary battery 2 and sufficient depth to store oil 3 so that the entire or at least a portion of the secondary battery 2 is submerged. Furthermore, the shape of the main body 11 is not limited to a box shape, and other shapes can be appropriately selected.

[0024] A lid 12 that closes the top opening of the main body 11 may be connected to one end of the top opening of the main body 11 via a known connecting member such as a hinge so as to be openable and closable. By closing the lid 12, the top opening of the main body 11 can be closed, so that the housing 1 can be safely moved with the secondary battery 2 immersed in oil 3. A known sealing member such as a gasket may be provided at the part where the lid 12 and the top opening of the main body 11 come into contact in order to improve airtightness when the lid 12 is closed.

[0025] A drain port 13 is provided on the side wall of the main body 11. By discharging the oil 3 stored inside the main body 11 to the outside of the main body 11 through the drain port 13, the recovery of used oil 3 becomes easier. The drain port 13 may also be provided on the bottom surface of the main body 11. Furthermore, the size and shape of the drain port 13 are not particularly limited.

[0026] The housing 1 can be formed from various known materials, such as metal or plastic, and is preferably oil-resistant. The housing 1 may be formed from the same type of material for the main body 11 and the lid 12, or the main body 11 and the lid 12 may be formed from different types of materials.

[0027] The housing 1 is preferably a portable housing. Because the housing 1 is portable, the recovery and transport of the secondary battery can be carried out in oil, thus enabling safe recovery and transport of the secondary battery. Furthermore, because the housing 1 is portable, each step of the secondary battery destruction method according to one aspect of the present invention can be easily carried out in different locations, allowing each step to be performed under an environment suitable for that step. Here, "portable" means that the housing's installation location can be moved. The method of moving the housing is not particularly limited. For example, the housing may be moved on a vehicle, or it may be moved using means of movement such as casters provided on the bottom of the housing.

[0028] Figure 1 shows an example configuration in which the lid 12 is a hinged lid, but the lid 12 may be configured as a separate part without being connected to the main body 11. For example, the lid 12 may be a detachable lid or a sliding lid. It is also possible for the housing 1 to be configured without a lid 12.

[0029] <Oil> The specific type of oil that can be used in the method for destroying a secondary battery according to one aspect of the present invention is not particularly limited. Examples of oils that can be used include mineral oil, vegetable oil, synthetic oil, etc. Examples of mineral oils include paraffinic base oil and naphthenic base oil.

[0030] The oil is preferably one with a flash point of 250°C or higher. Oils with a flash point of 250°C or higher are classified as "flammable liquids" under the Fire Service Act enacted in Japan in 2002. Therefore, oils with a flash point of 250°C or higher offer superior safety and handling. Here, from the viewpoint of improving safety and handling, the flash point of the oil is preferably 255°C or higher, more preferably 260°C or higher, and even more preferably 265°C or higher. In this specification, the flash point of the oil refers to the value measured by the Cleveland Open Cumulonimbus (COC) method in accordance with JIS K2265-4:2007.

[0031] The following describes in detail each step included in the method for destroying a secondary battery according to one aspect of the present invention.

[0032] <1.Preparation process> The preparation step is to prepare a housing in which a secondary battery is placed and in which oil is stored so that at least a portion of the secondary battery is submerged.

[0033] By immersing the secondary battery in oil so that at least a portion of it is submerged, the desired effects can be achieved in the processes from the preparation step onward. In the preparation step, by appropriately adjusting the amount of oil stored in the housing, the direction in which the secondary battery is immersed in the oil, etc., the secondary battery can be immersed in oil so that at least a portion of it is submerged.

[0034] From the viewpoint of achieving the intended effect, it is preferable to adjust the amount of oil stored in the housing, the direction in which the secondary battery is immersed in the oil, etc., in the preparation step so that the electrodes and electrolyte can be sufficiently immersed in the oil after the housing of the secondary battery is destroyed in the battery destruction step.

[0035] Furthermore, from the viewpoint of achieving the desired effects even more effectively in the transport and battery destruction processes described later, it is preferable that a larger portion of the secondary battery is immersed in oil. For example, it is preferable to immerse the secondary battery in oil so that 50% or more of its volume (e.g., 60% or more, 70% or more, 80% or more, or 90% or more) is submerged below the oil surface, and it is more preferable to immerse the secondary battery in oil so that 100% of its volume (i.e., the entire secondary battery) is submerged below the oil surface.

[0036] The degree of cooling by oil is determined by the amount of oil. By adjusting the amount of oil stored in the casing, it is possible to adjust the upper limit of the secondary battery's temperature rise (for example, 80°C, 200°C, etc.). The more of the secondary battery immersed in oil, the lower the upper limit of the secondary battery's temperature rise can be controlled by the cooling effect of the oil.

[0037] In the preparation step, the number of secondary batteries introduced into a single housing and immersed in oil may be one or multiple. Furthermore, secondary batteries to which the secondary battery destruction method according to one aspect of the present invention can be applied include large to medium-sized secondary batteries used in automobiles and stationary batteries, as well as small secondary batteries such as household secondary batteries.

[0038] When multiple rechargeable batteries are placed in a single enclosure, they may collide with each other, making them more susceptible to external shocks than when there is only one battery. However, by immersing the batteries in oil, the oil can cushion external shocks to the batteries, thus preventing damage to the internal structure of the batteries due to external shocks. Furthermore, the cooling effect of the oil keeps the temperature of the batteries below specified values ​​(especially below 80°C, below 200°C, etc.), thus preventing overheating.

[0039] Therefore, according to one aspect of the present invention, a method for destroying secondary batteries can safely destroy multiple secondary batteries within a single housing, leading to a significant reduction in processing costs and processing time for destroying secondary batteries.

[0040] The preparation step may include sub-steps as needed. In one embodiment, the preparation step may include an oil introduction step of introducing the oil into the housing and a secondary battery introduction step of immersing at least a portion of the secondary battery in the oil inside the housing. Each sub-step of the preparation step will be described in detail below.

[0041] (Oil introduction process) The oil introduction process is the process of introducing oil into the enclosure. The introduction of oil into the enclosure may be done manually or automatically by a quantitative supply device or the like.

[0042] (Secondary battery introduction process) The secondary battery installation process involves installing the secondary battery into the housing and immersing at least a portion of the secondary battery in the oil inside the housing. The installation of the secondary battery into the housing may be done manually or automatically by a robot or crane.

[0043] (Order of performing sub-processes in the preparation process) The order of the oil introduction process and the secondary battery introduction process is not particularly limited. For example, the secondary battery introduction process may be performed after the oil introduction process, or in the reverse order. Alternatively, the oil introduction process and the secondary battery introduction process may be performed simultaneously. Furthermore, the amount of oil stored in the housing may be adjusted by repeating the oil introduction process as needed, so that at least a portion of the secondary battery is immersed in oil.

[0044] (Other sub-processes of the preparation process) The preparation process may include sub-processes other than those mentioned above. For example, it may include a housing preparation process to prepare the housing before the oil introduction process and the secondary battery introduction process.

[0045] <2. Battery Destruction Process> The battery destruction step is a step performed after the preparation step in which at least a portion of the secondary battery is immersed in the oil, and at least the portion of the secondary battery immersed in the oil is destroyed. Because the battery destruction step is performed in oil, the following effects are achieved. (i) When the outer casing of a secondary battery is damaged, oil can block air, which is a source of oxygen, and water, which is a source of hydrogen and can cause thermal runaway, from entering the inside of the battery. In addition, as oil flows into the inside of the secondary battery through the damaged part of the outer casing, the electrodes inside the secondary battery are immersed in oil, which prevents the electrodes from reacting with air and water. As a result, the secondary battery can be prevented from overheating. (ii) Due to the cooling effect of the oil, the temperature of the secondary battery will only rise to a specified temperature (e.g., 80°C, 200°C, etc.), so even if a short circuit occurs, overheating can be prevented. (iii) As a result of the destruction of the secondary battery's casing, the electrolyte that causes a short circuit leaks out of the secondary battery into the oil, so the electrolyte can be safely rendered harmless without coming into contact with air and water.

[0046] After destroying the secondary battery in oil using a battery destruction process, the electrodes are removed from the destroyed secondary battery. This allows the electrodes to be removed without generating heat, as the electrolyte is rendered harmless by the battery destruction process.

[0047] In this specification, the destruction of a secondary battery means at least the destruction of the casing of the secondary battery, but other structures of the secondary battery may also be destroyed as a result of the destruction of the secondary battery.

[0048] By destroying the outer casing, the seal on the inside of the secondary battery created by the casing is broken, allowing the electrolyte to leak out of the secondary battery, and also allowing oil to flow into the secondary battery, thus immersing the electrodes inside the secondary battery in oil.

[0049] In the battery destruction process, by destroying at least the portion of the secondary battery immersed in oil, the oil can block air, which is an oxygen source, and water, which is a hydrogen source and can cause thermal runaway, from entering the battery. In addition, the electrolyte can be released into the oil without coming into contact with air and water. Furthermore, as oil flows into the secondary battery from the destroyed part, the electrodes inside the secondary battery are immersed in oil, preventing the electrodes from reacting with air and water. Moreover, the cooling effect of the oil prevents the temperature of the secondary battery from rising beyond a specified temperature (e.g., 80°C, 200°C, etc.), thus preventing overheating even in the event of a short circuit.

[0050] In the battery destruction process, the degree of destruction of the secondary battery is not particularly limited. A portion of the casing may be destroyed to the extent that the electrolyte can leak out of the secondary battery.

[0051] In the battery destruction process, the method of destroying the secondary battery is not particularly limited and can be used by known methods such as crushing or cutting. Crushing can be performed using, for example, a known crushing device. Cutting can be performed using, for example, a known cutting device such as a jaw crusher.

[0052] <3. Post-processing steps> A method for destroying a secondary battery according to one aspect of the present invention may further include a post-processing step of processing at least one of the secondary battery and the oil after the battery destruction step.

[0053] The post-processing steps include any treatment of the secondary battery and oil after the battery destruction step, and the specific type of treatment is not particularly limited. Examples of treatments for the secondary battery after the battery destruction step include treatment to obtain a battery calcined product (also called "black mass") from the secondary battery after the battery destruction step, and treatment to remove electrodes from the secondary battery after the battery destruction step.

[0054] According to one aspect of the present invention, in a method for destroying a secondary battery, the battery is rendered harmless by a battery destruction process, and then the above-mentioned treatment is performed on the secondary battery. As a result, the secondary battery does not generate heat during the post-processing step, and the secondary battery can be safely disposed of.

[0055] Furthermore, treatment of the oil after the battery destruction process can include, for example, recovering the oil from the casing and recycling the recovered oil. This allows the oil used in the secondary battery destruction method according to one aspect of the present invention to be recovered and recycled.

[0056] A method for destroying a secondary battery according to one aspect of the present invention may be one that does not include a post-processing step.

[0057] The post-processing step may include sub-steps as needed. For example, the post-processing step may include at least one of the following sub-steps (I) to (IV): (I) An incineration step in which the secondary battery after the battery destruction step is incinerated in the housing with at least a portion of the secondary battery immersed in the oil; (II) An oil discharge step of discharging the oil from inside the housing to the outside of the housing; (III) A distillation step of distilling the oil to remove the electrolyte from the oil; (IV) A battery disassembly step, which involves removing electrodes from the secondary battery after the battery destruction step.

[0058] The following provides a detailed explanation of each sub-process (I) to (IV) of the post-processing steps.

[0059] (I) Incineration process The incineration process is a process of incinerating the secondary battery after the battery destruction process within the housing while at least a portion of the secondary battery is immersed in the oil.

[0060] By including an incineration process in the post-processing steps, black mass of secondary batteries can be obtained after the battery destruction process. This black mass contains non-ferrous metals such as lithium, cobalt, manganese, and nickel, which are present in the positive electrode active material of the secondary battery. The black mass obtained in the incineration process can be used as a raw material for rare metals such as lithium, cobalt, manganese, and nickel.

[0061] In the incineration process, at least a portion of the secondary battery after the battery destruction process is immersed in oil while it is incinerated. This prevents the highly reactive metal from reacting with air and water during incineration. Furthermore, the cooling effect of the oil keeps the temperature of the secondary battery below a specified value (especially below 80°C, below 200°C, etc.). As a result, abnormal heat generation of the secondary battery during the incineration process can be suppressed. In addition, the oil also has the effect of assisting the combustion of the secondary battery.

[0062] In the incineration process, black mass can be obtained by incinerating the secondary battery after the battery destruction process at a temperature range of 250°C to 1000°C, for example. The temperature conditions in the incineration process are more preferably 300°C to 800°C, and most preferably 400°C to 700°C. The processing time for the incineration process can be adjusted according to the incineration state of the secondary battery, for example, it can be 10 minutes to 400 minutes, 30 minutes to 360 minutes, 45 minutes to 240 minutes, or 60 minutes to 120 minutes.

[0063] From the viewpoint of maximizing the cooling effect of oil and the air and water barrier effect of oil, it is preferable that a larger portion of the secondary battery is immersed in oil during the incineration process. For example, it is preferable that 50% or more of the volume of the secondary battery (e.g., 60% or more, 70% or more, 80% or more, or 90% or more) is submerged below the oil surface, and it is more preferable that 100% of the volume of the secondary battery (i.e., the entire secondary battery) is submerged below the oil surface.

[0064] ((II) Oil discharge process) The oil discharge process is a process of discharging the oil from inside the housing to the outside of the housing. The method of discharging the oil from inside the housing to the outside of the housing is not particularly limited. For example, as shown in Figure 1, if the housing 1 is equipped with an oil discharge port 13, the oil 3 can be discharged to the outside of the housing 1 from the oil discharge port 13. The oil may also be discharged to the outside of the housing by other methods. The oil discharge process allows for the recovery of used oil from the housing after the battery destruction process.

[0065] The oil discharged to the outside of the enclosure during the oil discharge process may be subjected to the distillation process described later, or it may be discarded depending on the condition of the recovered oil.

[0066] (III) Distillation Process The distillation process involves distilling the oil after the battery destruction process to remove the electrolyte. This allows for the removal of the electrolyte (more specifically, the electrolyte solution) from the oil, enabling its recycling. The electrolyte solution distilled during the distillation process can also be recycled.

[0067] The method of removing the electrolyte from the oil by distillation is not particularly limited.

[0068] The distillation process may be performed (i) with the oil stored in the casing after the battery destruction process, or (ii) on the oil discharged to the outside of the casing by the oil discharge process. From the viewpoint of facilitating distillation, it is preferable to perform the distillation process on the oil discharged to the outside of the casing by the oil discharge process.

[0069] ((IV) Battery disassembly process) The battery disassembly process is a process of removing electrodes from the secondary battery after the battery destruction process. The battery disassembly process allows for the removal of electrodes from the secondary battery after the battery destruction process. The electrodes removed in the battery disassembly process may be recycled.

[0070] The method for removing electrodes from a secondary battery after the battery destruction process is not particularly limited.

[0071] The electrodes removed from the secondary battery during the battery disassembly process may be either the positive electrode or the negative electrode, or both.

[0072] The positive electrode, for example in the case of a lithium-ion battery, comprises a positive electrode current collector and a positive electrode active material. In addition to the above, the positive electrode may also contain a binder, conductive additives, electrolyte, etc. The positive electrode active material may include substances such as lithium, cobalt, manganese, iron, and phosphorus.

[0073] The negative electrode, for example in the case of a lithium-ion battery, comprises a negative electrode current collector and a negative electrode active material. In addition to the above, the negative electrode may also contain a binder, conductive additives, electrolyte, etc. The negative electrode active material may include, for example, aluminum, tin, magnesium, silver, antimony, carbon, etc.

[0074] According to the battery disassembly process, electrodes containing the above-mentioned useful substances can be safely extracted from secondary batteries.

[0075] The battery decomposition process involves removing at least the electrodes from the secondary battery after the battery destruction process, but other materials besides electrodes may also be extracted during the battery decomposition process. Such materials may also be recycled.

[0076] The battery disassembly process may be performed (i) inside the housing while the oil is still stored before the oil discharge process, or (ii) inside the housing after the oil discharge process. Alternatively, (iii) the secondary battery may be removed from the housing after the battery destruction process and the process may be performed outside the housing. From the viewpoint of ease of disassembly, it is preferable to perform the battery disassembly process inside the housing after the oil discharge process.

[0077] (Variations of sub-processes included in the post-processing steps and the order in which the sub-processes are carried out) The variations of the sub-processes included in the post-processing steps may be, for example, any of the following: (a) The post-processing step includes an incineration step; (b) The post-treatment process includes an incineration process and an oil discharge process; (c) The post-treatment process includes incineration, oil discharge, and distillation; (d) The post-processing steps include a battery disassembly step; (e) The post-processing steps include a battery disassembly step and an oil discharge step; (f) The post-processing steps include a battery disassembly step and a distillation step; (g) The post-processing steps include a battery disassembly step, an oil discharge step, and a distillation step; (h) The post-treatment process includes an oil discharge process; (i) The post-processing steps include distillation steps; (j) The post-treatment process includes an oil discharge process and a distillation process.

[0078] If the post-processing step includes an incineration step and an oil discharge step as described in (b) or (c) above, some of the oil inside the housing may be removed in the oil discharge step, and then the incineration step may be carried out. When some of the oil inside the housing is removed in the oil discharge step, it is preferable that a larger portion of the secondary battery is immersed in oil in the incineration step, from the viewpoint of better demonstrating the cooling effect of the oil and the air and water barrier effect of the oil. Therefore, when some of the oil inside the housing is removed in the oil discharge step, it is preferable that after the oil discharge step, for example, 50% or more of the volume of the secondary battery (for example, 60% or more, 70% or more, 80% or more, or 90% or more) is submerged below the oil surface, and it is more preferable that 100% of the volume of the secondary battery (i.e., the entire secondary battery) is submerged below the oil surface.

[0079] Furthermore, if the post-treatment process includes an oil discharge process and a distillation process, as described in (c), (g), or (j) above, it is preferable to perform the distillation process after the oil discharge process.

[0080] Furthermore, in the case of (c) above, the post-treatment process may consist of performing the oil discharge process followed by the incineration or distillation process. The order of the incineration and distillation processes in this case is not particularly limited. For example, the distillation process may be performed after the incineration process, or in the reverse order. Alternatively, the incineration and distillation processes may be performed simultaneously.

[0081] Furthermore, in the case of (d) above, the battery disassembly process may be carried out inside the housing in which oil is stored, or the battery disassembly process may be carried out outside the housing after the secondary battery has been removed from the housing after the battery destruction process.

[0082] Furthermore, if the post-processing step includes a battery disassembly step and an oil discharge step, as described in (e) or (g) above, it is preferable to perform the battery disassembly step after the oil discharge step. In the oil discharge step, some of the oil inside the housing may be removed, or all of the oil inside the housing may be removed.

[0083] Furthermore, in case (f) above, the order of the battery disassembly process and the distillation process is not particularly limited. For example, the distillation process may be performed after the battery disassembly process, or in the reverse order. Alternatively, the battery disassembly process and the distillation process may be performed simultaneously.

[0084] Furthermore, in the case of (g) above, the post-treatment step may consist of performing the oil discharge step followed by the distillation step or the battery disintegration step. The order of the battery disintegration step and the distillation step in this case is not particularly limited. For example, the distillation step may be performed after the battery disintegration step, or in the reverse order. Alternatively, the battery disintegration step and the distillation step may be performed simultaneously.

[0085] (Other sub-processes in the post-processing stage) The post-processing steps may include sub-steps other than those mentioned above.

[0086] <4. Enclosure Transportation Process> A method for destroying a secondary battery according to one aspect of the present invention may include a housing transportation step of transporting the housing by vehicle between the preparation step and the battery destruction step.

[0087] During the housing transportation process, by transporting the secondary battery in a housing with at least a portion of it immersed in oil, (i) external shocks applied to the secondary battery can be cushioned by the oil, thereby suppressing damage to the internal structure of the secondary battery due to external shocks. As a result, heat generation due to damage to the internal structure can be prevented. Also, (ii) because the secondary battery is immersed in oil, the temperature of the secondary battery can be kept below a specified value (especially below 80°C, below 200°C, etc.). Therefore, even if the secondary battery undergoes an abnormal reaction, ignition or explosion is unlikely to occur.

[0088] A method for destroying a secondary battery according to one aspect of the present invention may be one that does not include a housing transport step.

[0089] <5. Others> A method for destroying a secondary battery according to one aspect of the present invention includes the above-described preparation step and battery destruction step, and therefore, for the reasons stated above, it can be an embodiment that does not include a discharge step. In a method for destroying a secondary battery according to one aspect of the present invention, a discharge step may be provided before the battery destruction step, but the battery destruction step can be performed even if all of the battery has not been completely discharged.

[0090] [Embodiment 1] A method for destroying a secondary battery according to Embodiment 1 of the present invention will be described in detail with reference to Figure 2. Figure 2 is a flowchart showing the flow of the method for destroying a secondary battery according to Embodiment 1 of the present invention. The arrows in Figure 2 indicate the direction of the processing flow of the method for destroying a secondary battery according to Embodiment 1 of the present invention.

[0091] As shown in Figure 2, the method for destroying a secondary battery according to Embodiment 1 of the present invention first involves preparing a housing in which a secondary battery is placed and oil is stored so that at least a portion of the secondary battery is submerged, in a preparation step S1. Preparation step S1 includes a housing preparation step S11, an oil introduction step S12, and a secondary battery introduction step S13, and the housing preparation step S11, oil introduction step S12, and secondary battery introduction step S13 are carried out in this order.

[0092] Next, in the housing transportation process S2, the housing prepared in the preparation process S1 is transported by vehicle to the location where the next battery destruction process S3 will be carried out.

[0093] Next, in the battery destruction step S3, with at least a portion of the secondary battery immersed in the oil, at least the portion of the secondary battery immersed in the oil is destroyed.

[0094] Next, in the post-processing step S4, at least one of the secondary battery and the oil after the battery destruction step S3 is processed. The post-processing step S4 includes the incineration step S41.

[0095] As described above, each step included in the method for destroying a secondary battery according to Embodiment 1 of the present invention will not be explained here.

[0096] According to the method for destroying secondary batteries in Embodiment 1 of the present invention, secondary batteries can be destroyed safely and easily, and a black mass of secondary batteries can be obtained.

[0097] [Embodiment 2] A method for destroying a secondary battery according to Embodiment 2 of the present invention will be described in detail with reference to Figure 3. Figure 3 is a flowchart showing the flow of the method for destroying a secondary battery according to Embodiment 2 of the present invention. The arrows in Figure 3 indicate the direction of the processing flow of the method for destroying a secondary battery according to Embodiment 2 of the present invention.

[0098] As shown in Figure 3, the secondary battery destruction method according to Embodiment 2 of the present invention includes a post-treatment step S4 which comprises an oil discharge step S42, a distillation step S43, and a battery disassembly step S44. The steps prior to post-treatment step S4 are the same as those in the secondary battery destruction method according to Embodiment 1 of the present invention, so they will not be described again here.

[0099] The method for destroying a secondary battery according to Embodiment 2 of the present invention involves a battery destruction step S3 followed by a post-treatment step S4 in which at least one of the secondary battery and oil after the battery destruction step S3 is treated. The post-treatment step S4 includes an oil discharge step S42, a distillation step S43, and a battery disintegration step S44, wherein the distillation step S43 or the battery disintegration step S44 is performed after the oil discharge step S42 is carried out.

[0100] As described above, the steps included in the method for destroying a secondary battery according to Embodiment 2 of the present invention will not be explained here.

[0101] According to the secondary battery destruction method of Embodiment 2 of the present invention, secondary batteries can be destroyed safely and easily, and electrodes can be safely removed from secondary batteries. Furthermore, the used oil used in the battery destruction step S3 and the electrolyte removed in the battery destruction step S3 can be recovered and recycled.

[0102] <Variation> In the above description, an example was given of a configuration in which a post-processing step S4 is performed following the battery destruction step S3, but the present invention is not limited thereto. Another embodiment of the secondary battery destruction method of the present invention may also be a configuration in which the post-processing step S4 is not performed after the battery destruction step S3.

[0103] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0104] 〔summary〕 A method for destroying a secondary battery according to Embodiment 1 of the present invention includes a preparation step of preparing a housing in which a secondary battery is disposed and oil is stored so as to immerse at least a portion of the secondary battery, and a battery destruction step of destroying at least the portion of the secondary battery immersed in the oil, while at least a portion of the secondary battery is immersed in the oil, after the preparation step.

[0105] In the method for destroying a secondary battery according to aspect 2 of the present invention, in aspect 1 described above, it is preferable that the secondary battery is a lithium-ion battery.

[0106] The method for destroying a secondary battery according to embodiment 3 of the present invention may further include a post-processing step in which at least one of the secondary battery and the oil is processed after the battery destruction step, as in embodiment 1 or 2 described above.

[0107] A method for destroying a secondary battery according to aspect 4 of the present invention may include, in aspect 3 above, an incineration step in which the secondary battery after the battery destruction step is incinerated in the housing with at least a portion of the secondary battery immersed in the oil.

[0108] In the method for destroying a secondary battery according to aspect 5 of the present invention, the post-processing step in aspect 3 above may include an oil discharge step of discharging the oil from inside the housing to the outside of the housing.

[0109] In the method for destroying a secondary battery according to embodiment 6 of the present invention, the post-treatment step may include a distillation step of distilling the oil to remove the electrolyte from the oil, in the above embodiment 3 or 5.

[0110] The method for destroying a secondary battery according to embodiment 7 of the present invention may also include a battery disassembly step in which the post-processing step is to remove electrodes from the secondary battery after the battery destruction step, in embodiment 3, 5, or 6 described above.

[0111] In the method for destroying a secondary battery according to embodiment 8 of the present invention, in embodiment 6 or 7 described above, the post-treatment step may be a method in which the distillation step or the battery disassembly step is performed after the oil discharge step is performed.

[0112] The method for destroying a secondary battery according to aspect 9 of the present invention may also include a housing transport step between the preparation step and the battery destruction step, in any one of aspects 1 to 8 described above, wherein the housing is transported by vehicle.

[0113] A method for destroying a secondary battery according to embodiment 10 of the present invention may also include, in any one of embodiments 1 to 9 above, an oil introduction step of introducing the oil into the housing and a secondary battery introduction step of immersing at least a portion of the secondary battery in the oil inside the housing. [Industrial applicability]

[0114] This invention can be used in the disposal of secondary batteries, particularly lithium-ion batteries. [Explanation of Symbols]

[0115] 1 cabinet 2 Secondary battery 3 oil 11 Main body 12 Lid 13 Oil drain port S1 Preparation process S11 Enclosure preparation process S12 Oil introduction process S13 Secondary battery introduction process S2 Enclosure transportation process S3 Battery Destruction Process S4 Post-processing process S41 Incineration Process S42 Oil discharge process S43 Distillation Process S44 Battery disassembly process

Claims

1. Preparation steps include preparing a housing in which a secondary battery is arranged and oil is stored so that at least a portion of the secondary battery is submerged, After the preparation step, a battery destruction step is performed in which, with at least a portion of the secondary battery immersed in the oil, at least the portion of the secondary battery immersed in the oil is destroyed. A method for destroying secondary batteries, including [specific components / materials].

2. The method for destroying a secondary battery according to claim 1, wherein the secondary battery is a lithium-ion battery.

3. A method for destroying a secondary battery according to claim 1 or 2, further comprising a post-processing step of processing at least one of the secondary battery and the oil after the battery destruction step.

4. The method for destroying a secondary battery according to claim 3, wherein the post-processing step includes an incineration step of incinerating the secondary battery after the battery destruction step in the housing with at least a portion of the secondary battery immersed in the oil.

5. The method for destroying a secondary battery according to claim 3, wherein the post-processing step includes an oil discharge step of discharging the oil from inside the housing to the outside of the housing.

6. The method for destroying a secondary battery according to claim 3 or 5, wherein the post-processing step includes a distillation step of distilling the oil to remove the electrolyte from the oil.

7. The method for destroying a secondary battery according to claim 3, 5, or 6, wherein the post-processing step includes a battery disassembly step of removing electrodes from the secondary battery after the battery destruction step.

8. The method for destroying a secondary battery according to claim 6 or 7, wherein the post-treatment step is performed after the oil discharge step, the distillation step or the battery disassembly step is performed.

9. A method for destroying a secondary battery according to any one of claims 1 to 8, further comprising a housing transport step of transporting the housing by vehicle between the preparation step and the battery destruction step.

10. The aforementioned preparation step is, An oil introduction step for introducing the oil into the housing, A secondary battery introduction step involves immersing at least a portion of the secondary battery in the oil inside the housing, A method for destroying a secondary battery according to any one of claims 1 to 9, including the following:

Images