Battery processing method and battery processing system

Abstract

This invention provides a battery processing method and a battery processing system that can efficiently recover lithium from lithium-ion batteries. [Solution] A battery processing method for processing a lithium-ion battery comprising a positive electrode material and a negative electrode material, the method comprising a first lithium deposition step of performing pulse charging while cooling the lithium-ion battery to deposit lithium on the negative electrode material.

Description

Technical Field

[0001] The present invention relates to a battery processing method and a battery processing system.

Background Art

[0002] In recent years, the adoption of lithium-ion batteries as in-vehicle batteries for electric vehicles such as electric vehicles and hybrid vehicles has been expanding. Lithium-ion batteries contain valuable substances containing lithium. It is required to recycle resources by recycling valuable substances from used lithium-ion batteries.

[0003] Patent Document 1 discloses a method of recovering lithium from a positive electrode material after increasing the amount of lithium contained in the positive electrode material by discharging a used lithium-ion battery.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The positive electrode material is generally composed of forming a positive electrode active material on a current collector foil such as aluminum. The positive electrode active material contains valuable substances such as nickel, manganese, cobalt, etc. in the case of a ternary system (NMC), for example. To recover valuable substances from the positive electrode active material, the positive electrode material is baked with a reducing agent, pulverized, and then a black mass containing the positive electrode active material is sorted. Next, the black mass is subjected to solvent extraction step by step, whereby manganese, cobalt, and nickel are sequentially extracted, and finally lithium is extracted. Therefore, it has been particularly laborious to recover lithium.

[0006] The object of this invention is to provide a battery processing method and a battery processing system that can efficiently recover lithium from lithium-ion batteries. [Means for solving the problem]

[0007] The present invention A battery processing method for processing a lithium-ion battery containing a positive electrode material and a negative electrode material, A first lithium deposition step involves performing pulse charging while cooling the lithium-ion battery to deposit lithium on the negative electrode material. The present invention provides a battery processing method that includes [a specific component]. [Effects of the Invention]

[0008] According to the present invention, lithium can be efficiently recovered from the negative electrode of a lithium-ion battery. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic block diagram illustrating the reuse system according to the first embodiment. [Figure 2] A perspective view showing the schematic configuration of a lithium-ion battery. [Figure 3] A cross-sectional view showing the general configuration of a battery cell. [Figure 4] A flowchart illustrating the general process of reusing lithium-ion batteries. [Figure 5] A schematic diagram illustrating an example of a cooling device according to the first embodiment. [Figure 6] A graph showing the relationship between the charge rate relative to the State of Charge (SOC) and the ease of lithium deposition at different cooling temperatures. [Modes for carrying out the invention]

[0010] The inventors have diligently conducted research to efficiently recover lithium from lithium-ion batteries and have discovered that lithium can be efficiently recovered from lithium-ion batteries by intentionally inducing lithium deposition (e.g., dendrites), which is undesirable in normal charging reactions, on the negative electrode material. Based on this finding, the inventors have completed a battery processing method that can efficiently recover lithium from lithium-ion batteries.

[0011] A method for reusing lithium-ion batteries according to one embodiment of the present invention is: A battery processing method for processing a lithium-ion battery containing a positive electrode material and a negative electrode material, A first lithium deposition step involves performing pulse charging while cooling the lithium-ion battery to deposit lithium on the negative electrode material. It includes.

[0012] [First Embodiment] Hereinafter, a lithium-ion battery reuse system according to the first embodiment of the present invention will be described with reference to the attached drawings. Figure 1 is a schematic block diagram showing a lithium-ion battery reuse system 200. As shown in Figure 1, the reuse system 200 includes a reuse unit 10 that reuses a lithium-ion battery 1 that has been used primarily in, for example, an electric vehicle, and a recycling unit 20 that recovers lithium from the reused lithium-ion battery 1.

[0013] The reuse unit 10 reuses the lithium-ion battery 1, which has been used for its primary purpose, as an energy storage device. Generally, the degradation state of lithium-ion batteries for electric vehicles is determined based on the State of Health (SOH), which indicates how much capacity they have when fully charged compared to when they were new. If the lithium-ion battery 1 is determined to be unsuitable for use in an electric vehicle based on its degree of degradation, it is removed from the vehicle and used in the reuse unit 10 as an energy storage device for various secondary purposes, such as storing renewable energy such as solar power and wind power, or as a backup power source during disasters. For example, if the SOH falls below 70%, it may be determined that it is unsuitable for primary use, i.e., for use in an electric vehicle.

[0014] The reuse section 10 includes a lithium-ion battery 1 that is secondarily used as a power storage device, a charging device 12, and a cooling device 201. The charging device 12 is configured to adjust the voltage and current and be capable of intermittently charging at a predetermined voltage and current (also referred to as pulse charging). The upper limit of the charging voltage by the charging device 12 is below the withstand voltage of the lithium-ion battery 1, for example, 4.3 V or less.

[0015] The cooling device 201 is not limited and may be any type of cooling device. In this embodiment, a thermostatic bath is employed as the cooling device 201.

[0016] When it is determined that the lithium-ion battery 1 cannot be properly used in the above secondary use, for example, based on the SOH, the recycling section 20 includes a disassembling device 21 that disassembles the lithium-ion battery 1 into a positive electrode material 31, a negative electrode material 35, etc. through a lithium precipitation process described later, an extraction device 22 that extracts lithium from the disassembled negative electrode material 35, and a recovery device 23 that recovers the extracted lithium. For example, when the SOH becomes 40% or less, it may be determined that it cannot be properly used in secondary use either.

[0017] FIG. 2 schematically shows the lithium-ion battery 1 mounted on an electric vehicle. The lithium-ion battery 1 constitutes a battery pack in which battery modules 4 incorporate functions such as a charge / discharge circuit and a cooling mechanism, and further, a plurality of battery modules 4 are connected to each other and housed in a case. The battery module 4 is configured by connecting a plurality of battery cells 3 in series or in parallel to each other and is adjusted to a desired capacity and voltage.

[0018] The lithium-ion battery 1 is a rechargeable lithium-ion secondary battery. In this specification, the term "lithium-ion battery" may collectively refer to battery cells, battery modules, and battery packs unless otherwise specified.

[0019] FIG. 3 is a cross-sectional view schematically showing the battery cell 3. As shown in FIG. 3, the battery cell 3 according to this embodiment is a laminated type. The battery cell 3 has a laminated electrode body 38 in which a positive electrode material 31, a separator 34, and a negative electrode material 35 are laminated in this order in the stacking direction A, and a case 40 that houses the laminated electrode body 38.

[0020] In this embodiment, the laminated electrode body 38 is configured by laminating a plurality of sets of a positive electrode material 31, a separator 34, and a negative electrode material 35 in the stacking direction A. The laminated electrode body 38 has a positive electrode current collector end portion 32a to which a plurality of positive electrode current collectors 32 are connected at one end portion (the left side in FIG. 3) in the width direction B (the left-right direction in FIG. 3) orthogonal to the stacking direction A, and a negative electrode current collector end portion 36a to which a plurality of negative electrode current collectors 36 are connected at the other end portion (the right side in FIG. 3). The battery cell 3 has an elongated rectangular shape in the width direction B when viewed from the stacking direction A.

[0021] The positive electrode material 31 has a positive electrode current collector 32 and a positive electrode active material 33 laminated on the surface of the positive electrode current collector 32 facing the separator 34. The plurality of positive electrode current collectors 32 have a positive electrode current collector end portion 32a connected to each other at one end portion (the left side in FIG. 3) in the width direction B orthogonal to the stacking direction. A metal foil suitable for the positive electrode can be preferably used for the positive electrode current collector 32. As the positive electrode active material 33, a material used as a positive electrode active material of a lithium-ion secondary battery can be used. In this embodiment, the positive electrode current collector 32 is made of aluminum, and the positive electrode active material 33 is made of NMC (nickel, manganese, cobalt).

[0022] The negative electrode material 35 comprises a negative electrode current collector 36 and a negative electrode active material 37 laminated on the surface of the negative electrode current collector 36 facing the separator 34. Multiple negative electrode current collectors 36 have negative electrode current collector ends 36a connected to each other at their other ends (right side in Figure 3) in the width direction B. A metal foil suitable for a negative electrode can preferably be used for the negative electrode current collector 36. A material used as a negative electrode active material for lithium-ion secondary batteries can be used for the negative electrode active material 37. In this embodiment, the negative electrode current collector 36 is made of copper, and the negative electrode active material 37 is a carbon material (graphite) with a layered structure.

[0023] The positive electrode active material 33 and the negative electrode active material 37 contain an electrolyte 39. The electrolyte 39 is, for example, an organic solvent on which lithium ions can move. In this embodiment, the electrolyte 39 contains dimethyl carbonate (DMC), ethylene carbonate (EC), and diethyl carbonate (DEC) in a volume ratio of 1:1:1, and lithium hexafluoride phosphate (LiPF6) at a concentration of 1 mol / L.

[0024] The separator 34 is positioned between the positive electrode material 31 and the negative electrode material 35, physically and electrically separating them. The separator 34 may be a porous material having multiple minute pores through which lithium ions can pass. In this embodiment, the separator 34 is a porous membrane made of polyolefin.

[0025] Case 40 has a pair of first cases 41 and second cases 42 provided on both sides of the stacking direction A of the stacked electrode body 38. The first case 41 and the second case 42 are formed in a hat-shaped cross section. The first case 41 has a pair of flange portions 41a located at both ends in the width direction B, and a main body portion 41b located between the pair of flange portions 41a and bulging in a direction away from the second case 42 in the stacking direction A. Similarly, the second case 42 has a pair of flange portions 42a and a main body portion 42b bulging in a direction away from the first case 41.

[0026] Case 40 is formed by joining a first case 41 and a second case 42 with the positive electrode current collector end 32a and the negative electrode current collector end 36a sandwiched between their respective flange portions 41a and 42a. That is, with the laminated electrode body 38 housed in case 40, the positive electrode current collector end 32a and the negative electrode current collector end 36a are sandwiched between the pair of flange portions 41a and 42a, and the remaining portion of the laminated electrode body 38 is housed in the space defined between the pair of main body portions 41b and 42b. With the laminated electrode body 38 housed in case 40, it is pressed against the pair of main body portions 41b and 42b at a predetermined pressure in the stacking direction A. An example of the tab 43 according to the present invention is formed by the portion of the battery cell 3 sandwiched between the pair of flange portions 41a and 42a.

[0027] Next, the reuse of lithium-ion battery 1 will be explained. Figure 4 is a flowchart that schematically shows the reuse process of lithium-ion battery 1. As shown in Figure 4, if lithium-ion battery 1 that was installed in an electric vehicle is determined to be in a deteriorated state that makes it unsuitable for use in an electric vehicle, for example based on SOH, it is removed from the electric vehicle and a reuse process (step S1) is carried out in the reuse unit 10 for secondary use.

[0028] When the lithium-ion battery 1 is used for secondary purposes and is used as an energy storage device 11, and is determined to be in a predetermined state of degradation, the reuse unit 10 performs a lithium deposition process (step S2) to deposit lithium onto the negative electrode material 35, following the secondary use. In the lithium deposition process S2, lithium is deposited onto the negative electrode material 35. In the lithium deposition process S2, pulse charging is performed on the lithium-ion battery 1 while cooling it to deposit lithium onto the negative electrode material 35.

[0029] Figure 5 is a schematic diagram of the cooling device 201. Figure 5 also schematically shows the battery cell 3 that is cooled by the cooling device. As shown in Figure 5, the cooling device 201 is provided in pairs on both sides of the stacking direction A of the battery cell 3. Alternatively, one side of the pair of cooling devices 201 may be in a form in which a single cooler covers the entire width direction B of the battery cell 3, or, as shown in Figure 5, it may be in a form in which multiple pairs of cooler 202 are divided along the width direction B of the battery cell 3. In this embodiment, there is a central cooler pair 202A that cools the central part 3a of the battery cell 3, and cooler pairs 202B and 202C that cool both sides 3b and 3c of the battery cell 3. When the cooler pairs 202 are divided, they are not limited to three, but may be divided into two or four or more. For example, by cooling the battery cell 3 with only the central cooler pair 202A, lithium is preferentially deposited in the negative electrode material 35 located in the central part rather than at the ends in the width direction B. Furthermore, the coolers are not limited to a pair configuration; for example, they may be arranged only on one side of the stacking direction A (the upper or lower side in Figure 5).

[0030] In the lithium deposition process S2, the lithium-ion battery 1 is charged while being cooled by the cooling device 201 under predetermined cooling conditions. Here, the graph in Figure 6 shows the relationship between the charge rate relative to the State of Charge (SOC) and the ease of lithium deposition for each temperature. Specifically, lithium is more likely to be deposited on the negative electrode material 35 when charging is performed in the region above the curve at each temperature. SOC is an index that indicates the charge state of the battery, and represents the battery capacity when the fully charged state is 100% and the completely discharged state is 0%. As shown in Figure 6, lithium is more likely to be deposited in the lithium-ion battery 1 as the SOC increases and / or as the temperature decreases.

[0031] In the lithium deposition process S2, it is preferable to cool the lithium to the temperature at which deposition begins. Here, the "temperature at which deposition begins" is determined by the State of Charge (SOC) and charge rate of the lithium-ion battery 1. For example, Figure 6 shows the relationship between SOC and charge rate when the "temperature at which deposition begins" is 0°C, -10°C, or -20°C, as shown by a curve (hereinafter referred to as the "temperature curve"). For example, if X is the measured value of the SOC of the lithium-ion battery 1 to be reused, and Y is the charge rate in the arbitrarily selected lithium deposition process, then, as shown in Figure 6, the intersection of X and Y lies between the -10°C and -20°C temperature curves. In this case, -20°C to -10°C is the "temperature at which deposition begins". The method for measuring the SOC of the lithium-ion battery 1 is not particularly limited, and known methods may be used. For example, an SOC-open-circuit voltage (OCV) curve may be derived based on a known battery model for the lithium-ion battery 1 in question, and the OCV of the battery may be measured and applied to the SOC-OCV curve to calculate the SOC.

[0032] The cooling temperature varies depending on the operating environment and type of the lithium-ion battery 1. For example, if the lithium-ion battery 1 is a so-called capacity type (also called energy type) installed in an electric vehicle, the cooling temperature may be 20°C or lower, 10°C or lower, 0°C or lower, -5°C or lower, -10°C or lower, -20°C or lower, or -30°C or lower, and may be -50°C or higher, -40°C or higher, -30°C or higher, -25°C or higher, or -20°C or higher. From the viewpoint of reliably depositing lithium in the cooling portion, a temperature of 10°C or lower is preferred. In addition, to prevent lithium from depositing throughout the entire lithium-ion battery 1 due to excessive cooling, a cooling temperature of -40°C or higher is preferred. In one embodiment, the cooling temperature may be between -40°C and 10°C.

[0033] While not bound by theory, setting the cooling temperature within the above range allows for the deposition of lithium seed crystals relatively early in the lithium deposition process S2, potentially leading to the deposition of more lithium after the completion of the lithium deposition process S2.

[0034] In this specification, a lithium-ion battery 1 is described as a capacity-type battery if its energy density is 600 Wh / L or higher. A lithium-ion battery 1 is described as a high-power type battery if its power density (kW / kg or kW / L) is 4000 kW / L or higher.

[0035] The cooling rate during cooling may be, for example, 0.1°C / min to 50°C / min. From the viewpoint of unevenly distributing lithium deposition, a cooling rate of 1°C / min to 50°C / min is preferable. In this disclosure, "cooling rate" is a parameter based on the temperature inside the battery, not the ambient temperature.

[0036] Furthermore, in the lithium deposition process S2, the lithium-ion battery 1 is pulse-charged while being cooled to deposit lithium on the negative electrode material 35. By cooling the lithium-ion battery 1 in the lithium deposition process S2, lithium seed crystals can be deposited on the negative electrode material 35 relatively early during the pulse charging of this process. As pulse charging continues, lithium is successively deposited on these seed crystals, and lithium crystals grow. Therefore, depositing lithium seed crystals on the negative electrode material 35 at an early stage can lead to the deposition of more lithium after the completion of the lithium deposition process S2.

[0037] Furthermore, in the lithium deposition step S2, the lithium-ion battery 1 is pulse-charged. In conventional charging (also called continuous charging), the normal charging reaction may occur along with the deposition of lithium. On the other hand, when the lithium-ion battery 1 is subjected to pulse charging, which has a higher instantaneous output compared to continuous charging, more energy is expended on the lithium deposition reaction, which requires high energy, so more lithium can be deposited efficiently compared to the normal charging reaction.

[0038] The conditions for pulse charging vary depending on the operating environment and type of the lithium-ion battery 1. For example, if the lithium-ion battery 1 is a so-called capacitive type used in electric vehicles, the pulse charging frequency is 0.1 to 100 Hz, preferably 0.1 to 10 Hz, and more preferably 0.1 to 1 Hz. The pulse charging voltage can be 3.8 to 4.3 V.

[0039] Pulse charging is preferably performed using high-rate pulse charging. In this specification, high-rate pulse charging means charging with a large current that intentionally generates lithium in the negative electrode material 35 during pulse charging.

[0040] For example, if the lithium-ion battery 1 is a capacity type, it is preferable to pulse charge it with a current of, for example, 2C or more. Also, if the lithium-ion battery 1 is a so-called high-output type (also called a power type) installed in a hybrid vehicle, it is preferable to pulse charge it with a current of, for example, 10C or more. Here, a current of 1C means the current required to fully charge each lithium-ion battery in one hour. High-rate pulse charging allows for more efficient deposition of lithium on the negative electrode material 35 by intermittently charging over a predetermined period of time.

[0041] If the charging current due to high-rate pulse charging becomes excessive, undesirable side reactions may occur, such as gasification of the electrolyte 39 due to heat generation, deformation and damage to each component, and excessive charging current is undesirable from the standpoint of energy saving. For example, if the lithium-ion battery 1 is a capacity type, it is preferable to set the upper limit of the charging current to about 3C. On the other hand, if the lithium-ion battery 1 is a high-output type, it is preferable to set the upper limit of the charging current to about 20C.

[0042] In the lithium deposition step S2, the lithium-ion battery 1 only needs to be charged while cooled. The cooling of the lithium-ion battery 1 by the cooling device 201 and the charging of the lithium-ion battery 1 by the charging device 12 may be started simultaneously, or one may start first. That is, after cooling by the cooling device 201 is performed, charging by the charging device 12 may be performed while the cooled state by the cooling device 201 is maintained. From the viewpoint of depositing lithium seed crystals as early as possible, it is preferable to start cooling first.

[0043] Next, the lithium-ion battery 1 is removed from the reuse section 10 and the battery dismantling process (step S3) is performed by the dismantling device 21. In the battery dismantling process, the lithium-ion battery 1 is dismantled into its constituent components, such as the positive electrode material 31, separator 34, negative electrode material 35, and case 40. If the intention is to recover only lithium, at least the negative electrode material 35 may be dismantled. The dismantling device 21 may be any device that automatically dismantles the lithium-ion battery 1. Alternatively, the lithium-ion battery 1 may be dismantled manually using tools or the like without using the dismantling device 21.

[0044] Next, a lithium extraction process (step S4) is carried out. In lithium extraction process S4, lithium is extracted from the disassembled negative electrode material 35. In lithium extraction process S4, the negative electrode current collector 36 and negative electrode active material 37 are removed from the negative electrode material 35 by the extraction device 22, after which the negative electrode material 35 is leached with water and filtered, and an aqueous solution containing lithium ions is extracted.

[0045] Alternatively, lithium may be efficiently extracted by preferentially subjecting the portion of the disassembled negative electrode material 35 that has a larger amount of lithium deposited in the lithium deposition step S2 or the second lithium deposition step S22 described later to the lithium extraction step S4.

[0046] Finally, a lithium recovery process (step S5) is carried out. In lithium recovery process S5, lithium is recovered from an aqueous solution containing lithium ions. In lithium recovery process S5, the lithium is dissolved in carbonated water by the recovery device 23 and then filtered to recover lithium as lithium carbonate.

[0047] The negative electrode material 35 is generally constructed by laminating graphite in layers on a current collector foil made of, for example, copper. Therefore, it contains fewer valuable substances compared to the positive electrode material 31, which contains multiple valuable substances such as cobalt, nickel, and manganese. As a result, lithium can be efficiently recovered from the negative electrode material 35 without the need for stepwise solvent extraction of multiple valuable metals, as is required when recovering lithium from the positive electrode material 31.

[0048] In the first embodiment described above, the lithium-ion battery 1 is provided in the form of a battery pack in the reuse process S1, and then the lithium deposition process S2 is carried out as an example, but the invention is not limited to this. The lithium-ion battery 1 may be provided in the form of a battery module 4 or a battery cell 3 in the reuse process S1 and / or the lithium deposition process S2.

[0049] [Second Embodiment] In the second embodiment, lithium deposition step S12 is performed instead of lithium deposition step S2 according to the first embodiment. The lithium deposition step S12 differs in that, in addition to lithium deposition step S2 according to the first embodiment, a second lithium deposition step S22 is also employed. The second lithium deposition step S22 is a step in which the lithium-ion battery 1 is discharged, and then pulse charging is performed to deposit lithium on the negative electrode material 35, and this process is repeated at least once.

[0050] In the discharge in the second lithium deposition step S22, the discharge rate is not particularly limited, and for example, the discharge may be performed at the same rate as the charging performed in the lithium deposition step S2. Furthermore, the discharge may be pulsed discharge or continuous discharge, but continuous discharge is preferred.

[0051] The discharge in the second lithium deposition step S22 may be carried out by a reuse system 200 that newly includes a discharge device, as shown in Figure 1, or by employing a device capable of discharging as the charging device 12. The discharge device can adjust the voltage and current to continuously discharge at a predetermined voltage and current. Alternatively, it may be configured to discharge intermittently at a predetermined voltage and current. The upper limit of the discharge voltage by the discharge device is less than or equal to the withstand voltage of the lithium-ion battery 1, for example, 4.3V or less.

[0052] The cooling conditions in the second lithium deposition step S22 may be any of the conditions listed in the description of the lithium deposition step S2. Furthermore, depending on the degradation state of the battery, the absorption state of lithium ions in the negative electrode active material 37, etc., the cooling conditions in the second lithium deposition step S22 may be different from those in the lithium deposition step S2. For example, in the second lithium deposition step S22, from the viewpoint of depositing more lithium seed crystals than in the lithium deposition step S2, the cooling temperature may be 1°C, 2°C, 3°C, or 5°C lower than that of the lithium deposition step S2.

[0053] The pulse charging conditions in the second lithium deposition step S22 may be any of the conditions listed in the description of the lithium deposition step S2. Furthermore, depending on the battery degradation state, the cooling conditions in the second lithium deposition step S22 may differ from those in the lithium deposition step S2. For example, in the second lithium deposition step S22, the pulse charging rate may be higher than that of the lithium deposition step S22, from the viewpoint of depositing more lithium than in the lithium deposition step S22.

[0054] In the second lithium deposition step S22, discharge and pulse charging are performed at least once. From the viewpoint of depositing more lithium on the negative electrode material 35 after the completion of the second lithium deposition step S22, the number of repetitions of discharge and pulse charging may be 2 or more, 3 or more, 5 or more, 7 or more, 8 or more, or 10 or more, and is preferably 3 or more. Furthermore, as the number of repetitions of discharge and pulse charging increases, the amount of lithium that can be deposited on the negative electrode material 35 converges to a constant value, so an excessive number of repetitions leads to energy loss. Therefore, the number of repetitions may be 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, or 8 or less, and is preferably 10 or less.

[0055] During the second lithium deposition step S22, the rising temperature causes the re-ionized lithium to be absorbed in the region of the negative electrode active material 37 where lithium ion absorption capacity still remains (active region). Subsequent cooling and charging deposit more lithium, and further heating causes lithium ions to be absorbed in the active region of the negative electrode active material 37. By repeating this process, the total amount of lithium ions absorbed by the negative electrode active material 37 converges to a certain upper limit. Therefore, by repeating the heating, cooling, and charging steps in the second lithium deposition step S22 an appropriate number of times, more lithium can be deposited on the negative electrode material 35 compared to the case where only the second lithium deposition step S22 is performed.

[0056] In the second embodiment described above, the lithium-ion battery 1 is provided in the form of a battery cell 3 in the reuse process S1, and then the second lithium deposition process S12 is carried out as an example, but the invention is not limited to this. The lithium-ion battery 1 may be provided in the form of a battery pack or battery module 4 in the reuse process S1 and / or the second lithium deposition process S12. In this case, a cooling device 201 may be pre-built inside the battery pack or battery module 4.

[0057] The lithium-ion battery 1 reuse system 200 relating to this disclosure is not limited to the configuration described in the above embodiment, and various modifications are possible.

[0058] In the above embodiment, a laminated lithium-ion battery was described as an example, but it is not limited to this. For example, a cylindrical or rectangular lithium-ion battery may be used, which is constructed by winding a strip-shaped laminated electrode body, in which a strip-shaped positive electrode material, a strip-shaped separator, and a strip-shaped negative electrode material are stacked in the stacking direction A, into a cylindrical or rectangular shape. In the case of cylindrical and rectangular types, the stacking direction corresponds to the radial direction perpendicular to the winding direction.

[0059] Although the explanation was given on a cell-by-cell basis, it can also be done on a module-by-module or battery pack-by-battery basis. If done on a battery pack basis, a pressing device, cooling device, etc. may be pre-installed inside the battery pack.

[0060] [Note] According to the lithium-ion battery 1 reuse system 200 relating to this disclosure, the following aspects are provided.

[0061] [Aspect 1] A battery processing method for processing a lithium-ion battery containing a positive electrode material and a negative electrode material, A first lithium deposition step involves performing pulse charging while cooling the lithium-ion battery to deposit lithium on the negative electrode material. A battery processing method, including the following.

[0062] [Aspect 2] In the first lithium deposition step, the temperature is cooled to the point where lithium begins to precipitate. The battery processing method described in Embodiment 1.

[0063] [Aspect 3] The battery processing method according to embodiment 1 or 2, wherein in the first lithium deposition step, the lithium-ion battery is cooled to a temperature range of -40°C to 10°C.

[0064] [Aspect 4] The battery processing method according to any one of embodiments 1 to 3, wherein the first lithium deposition step is performed by high-rate pulse charging.

[0065] [Aspect 5] The battery processing method according to any one of embodiments 1 to 4, wherein in the first lithium deposition step, the pulse charging is performed at a pulse charging frequency of 0.1 Hz to 100 Hz.

[0066] [Aspect 6] A second lithium deposition step is performed, which involves discharging the lithium-ion battery after the first lithium deposition step, and then performing pulse charging to deposit lithium on the negative electrode material, and repeating this process at least once. A battery processing method according to any one of embodiments 1 to 5, further including the above.

[0067] [Aspect 7] A battery dismantling step, which involves dismantling at least the negative electrode material from the lithium-ion battery, A lithium extraction step for extracting lithium from the negative electrode material, A battery processing method according to any one of embodiments 1 to 6, further comprising the above.

[0068] [Aspect 8] A battery processing system for processing lithium-ion batteries, which include a positive electrode material and a negative electrode material, A cooling device capable of cooling the lithium-ion battery, The lithium-ion battery and a charging device capable of pulse charging A battery processing system, including a battery processing system.

[0069] [Aspect 9] The lithium-ion battery and a discharge device capable of discharging The battery processing system according to embodiment 8, further comprising: [Explanation of Symbols]

[0070] 1. Lithium-ion battery 3 battery cells 4 Battery Modules 10. Reuse Department 12 Charging device 20 Recycling Department 21 Demolition equipment 22 Extraction device 23 Recovery device 31 Cathode material 34 Separator 35. Negative electrode material 38. Stacked electrode body 39 Electrolyte 40 cases 200 Reuse Systems 201 Cooling device

Claims

1. A battery processing method for processing a lithium-ion battery containing a positive electrode material and a negative electrode material, A first lithium deposition step involves performing pulse charging while cooling the lithium-ion battery to deposit lithium on the negative electrode material. A battery processing method, including the following.

2. In the first lithium deposition step, the temperature is cooled to the point where lithium begins to precipitate. The battery processing method according to claim 1.

3. The battery processing method according to claim 1, wherein in the first lithium deposition step, the lithium-ion battery is cooled to a temperature range of -40°C to 10°C.

4. The battery processing method according to claim 1, wherein the first lithium deposition step is performed by high-rate pulse charging.

5. The battery processing method according to claim 1, wherein in the first lithium deposition step, the pulse charging is performed at a pulse charging frequency of 0.1 Hz to 100 Hz.

6. A second lithium deposition step is performed, which involves discharging the lithium-ion battery after the first lithium deposition step, and then performing pulse charging to deposit lithium on the negative electrode material, and repeating this process at least once. The battery processing method according to claim 1, further comprising:

7. A battery dismantling step, which involves dismantling at least the negative electrode material from the lithium-ion battery, A lithium extraction step for extracting lithium from the negative electrode material, The battery processing method according to claim 1, further comprising:

8. A battery processing system for processing lithium-ion batteries, which include a positive electrode material and a negative electrode material, A cooling device capable of cooling the lithium-ion battery, The lithium-ion battery and a charging device capable of pulse charging A battery processing system, including a battery processing system.

9. The lithium-ion battery and a discharge device capable of discharging The battery processing system according to claim 8, further comprising:

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