JP2020142228A - Processing system and processing method of waste lithium-ion battery - Google Patents

Abstract

To provide a processing system of a waste lithium-ion battery capable of heightening efficiency of heat treatment, and capable of heat-treating a large waste lithium-ion battery without dismantling it.SOLUTION: A processing system of a waste lithium-ion battery includes a heater 2 for heat-treating the waste lithium-ion battery at a heating temperature below 400°C in order to decompose and remove an electrolytic solution contained in the waste lithium-ion battery. The heater 2 can be constituted of a grate preheater for conveying to one direction, and simultaneously heat-treating the waste lithium-ion battery.SELECTED DRAWING: Figure 1

Description

The present invention relates to a treatment system and a treatment method for a waste lithium ion battery.

Lithium-ion batteries (LIBs) are widely used in electric vehicles, mobile phones, notebook computers, and the like. The lithium ion battery is composed of a positive electrode material, a negative electrode material, an electrolytic solution, a separator and the like. The positive electrode material is formed by fixing a positive electrode active material such as lithium cobalt oxide, lithium nickel oxide, and lithium manganate to an aluminum foil with a fluorine-based binder. The negative electrode material is formed by fixing a negative electrode active material such as graphite to a copper foil with a fluorine-based binder.

In order to recover useful metals such as cobalt, nickel, manganese, and lithium from discarded lithium-ion batteries (waste lithium-ion batteries) such as used lithium-ion batteries, detoxification (decomposition and removal) of electrolytes and separators Heat treatment is performed for the purpose of reducing the volume of combustible materials such as binders.

Large-scale waste lithium-ion batteries used in electric vehicles and the like have a form of a battery module in which a plurality of battery cells are combined and a form of a battery unit in which a plurality of battery modules are combined.

Such a large waste lithium-ion battery is usually disassembled manually and then roasted (heated), sorted, and the like to recover useful metals. In such a case, a lot of time and effort will be spent to disassemble the large waste lithium ion battery. In addition, since waste lithium-ion batteries contain an electrolytic solution with a low flash point, there is a risk of ignition or explosion if a short circuit occurs.

On the other hand, Patent Document 1 provides a heat-resistant container in which a circular heat-resistant furnace having a furnace body door is provided in one place and a battery module or battery unit (battery pack) composed of a plurality of lithium-ion batteries is stored. , Sequentially, the furnace body door is opened and closed and put into a heat treatment furnace set to a constant temperature for heat treatment, and the furnace body door is sequentially opened and closed to discharge the heat-resistant container from the heat treatment furnace. ing.

Japanese Unexamined Patent Publication No. 2016-22395

In the configuration of Patent Document 1, a large waste lithium ion battery composed of a battery module or a battery unit can be heat-treated, but the heat-resistant container is put into and discharged from the heat treatment furnace through one furnace body door. Therefore, there is room for improvement in improving the efficiency of heat treatment.

The present invention has been made to solve the above problems, and it is possible to improve the efficiency of heat treatment and to heat-treat a large-sized waste lithium-ion battery without disassembling it. It is an object of the present invention to provide a processing system and a processing method for a lithium ion battery.

In order to achieve the above object, the waste lithium ion battery treatment system according to an aspect of the present invention heats the waste lithium ion battery to less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery. It is equipped with a heating device that performs heat treatment according to temperature.

According to this configuration, the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. by a heating device to decompose and remove the electrolytic solution and detoxify the electrolytic solution. Here, by using a low oxygen gas such as a combustion gas (oxygen concentration 10% or less, preferably 5% or less) as the heating gas, ignition / explosion of the electrolytic solution or the like can be prevented, and the size of the heating device can be easily increased. The efficiency of the heat treatment can be improved, and the heat treatment can be performed without disassembling a large waste lithium ion battery.

Further, the heating temperature of the waste lithium ion battery by the heating device may be 150 ° C. or higher and 250 ° C. or lower.

Further, the heating device may be configured by a great preheater that performs heat treatment while transporting the waste lithium ion battery in one direction.

By configuring the heating device with a great preheater in this way, it is possible to continuously perform the heat treatment while transporting the waste lithium ion battery, so that the efficiency of the heat treatment can be improved.

Further, a crusher for crushing the waste lithium ion battery heat-treated by the heating device may be further provided.

According to this configuration, the waste lithium ion battery after the electrolytic solution is decomposed and removed (detoxified) is crushed by a crusher, so that it can be crushed while ensuring safety, and heat exchange is performed in the subsequent roasting apparatus. It is possible to improve the performance and shorten the processing time.

Further, even if the waste lithium ion battery crushed by the crusher is further provided with a roasting apparatus that heat-treats the waste lithium ion battery at a heating temperature of 400 ° C. or higher and lower than 660 ° C. in a reducing atmosphere or a low oxygen atmosphere. Good.

According to this configuration, organic substances such as separators and binders are decomposed, and heat treatment at a temperature (400 ° C. or higher and lower than 660 ° C.) at which aluminum used for the positive electrode material does not melt is crushed to increase the size. By performing this on a smaller waste lithium ion battery, heat exchangeability can be improved and the processing time can be shortened. It is also possible to reduce the size of the roasting apparatus.

Further, the roasting apparatus has a cylindrical body in which the inside is set to a reducing atmosphere or a low oxygen atmosphere and the outer wall is heated, and by rotating the cylindrical body, the roasting apparatus is received from the receiving port at one end of the cylindrical body. It may be composed of an externally heated rotary kiln that conveys the waste lithium ion battery toward the discharge port at the other end of the cylinder and discharges the waste lithium ion battery from the discharge port.

By configuring the roasting apparatus with an externally heated rotary kiln in this way, the receiving and discharging treatment of the waste lithium ion battery can be continuously performed, so that the efficiency of the heat treatment can be improved.

Further, in the waste lithium ion battery processing system, a crusher for crushing the waste lithium ion battery heat-treated by the heating device and a positive electrode collection for the waste lithium ion battery crushed by the crusher. A sorting machine that separates the positive electrode active material from the electric body and sorts the positive electrode active material, and a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere for the positive electrode active material sorted by the sorting machine. It may be further provided with a roasting apparatus for performing the heat treatment according to the above.

According to this configuration, the waste lithium ion battery heat-treated by the heating device is finely crushed by the crusher, the positive electrode active material is sorted by the sorting machine, and the positive electrode active material is heat-treated by the roasting device. Therefore, the roasting apparatus can be made smaller, and heat consumption can be suppressed because extra things such as an outer case and a current collector are not heated. Further, since the aluminum current collector that melts when the temperature is raised is removed before roasting, it is not necessary to set an upper limit of the roasting temperature.

Further, in the waste lithium ion battery treatment system, the positive electrode active material is separated from the positive electrode current collector of the waste lithium ion battery while crushing the waste lithium ion battery heat-treated by the heating device to separate the positive electrode active material. A crushing sorter that sorts active materials, and a roasting apparatus that heat-treats the positive electrode active material sorted by the crushing sorter at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere. May be further provided.

According to this configuration, the waste lithium-ion battery that has been heat-treated by the heating device is finely crushed by the crushing sorter, the positive electrode active material is sorted, and the waste lithium-ion battery is heat-treated by the roasting device. The roasting equipment can be made smaller, and heat consumption can be suppressed because extra things such as the outer case and current collector are not heated. Further, since the aluminum current collector that melts when the temperature is raised is removed before roasting, it is not necessary to set an upper limit of the roasting temperature.

Further, the roasting apparatus is configured to perform heat treatment in a reducing atmosphere when the waste lithium ion battery contains lithium, nickel, cobalt and manganese in the positive electrode active material, and the waste lithium ion battery is said to be said. When the positive electrode active material contains lithium, iron and phosphorus, the heat treatment may be performed in a low oxygen atmosphere.

In this way, by setting the internal atmosphere of the roasting apparatus according to the components contained in the positive electrode active material of the waste lithium ion battery, it is possible to improve the lithium recovery rate when recovering lithium in the subsequent process. ..

Further, in the method for treating a waste lithium ion battery according to an aspect of the present invention, the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery. 400 ° C. in a reducing atmosphere or a low oxygen atmosphere with respect to the heating step, the crushing step of crushing the waste lithium ion battery heat-treated by the heating step, and the waste lithium ion battery crushed by the crushing step. As described above, the roasting step of performing the heat treatment at a heating temperature of less than 660 ° C. is included.

According to this method, the electrolytic solution can be decomposed and removed and the electrolytic solution can be rendered harmless by heat-treating the waste lithium ion battery at a heating temperature of less than 400 ° C. in the heating step. Here, by using a low oxygen gas such as a combustion gas (oxygen concentration 10% or less, preferably 5% or less) as the heating gas, it is possible to prevent ignition and explosion of the electrolytic solution and the like, and the large size of the heating device used in the heating process. The heat treatment can be facilitated, the efficiency of the heat treatment can be improved, and the heat treatment can be performed without disassembling a large waste lithium ion battery. Next, in the crushing step, the waste lithium ion battery after the electrolytic solution is decomposed and removed is crushed, so that the crushing can be performed while ensuring safety. Next, in the roasting step, heat exchangeability can be improved and the processing time can be shortened by performing heat treatment on the waste lithium ion battery that has been crushed and reduced in size.

Further, in the method for treating a waste lithium ion battery according to an aspect of the present invention, the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery. The positive electrode active material is separated from the positive electrode current collector for the heating step, the crushing step of crushing the waste lithium ion battery heat-treated by the heating step, and the waste lithium ion battery crushed by the crushing step. A sorting step of selecting the positive electrode active material, and a roasting step of heat-treating the positive electrode active material selected by the sorting step at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere. And, including.

According to this method, the electrolytic solution can be decomposed and removed and the electrolytic solution can be rendered harmless by heat-treating the waste lithium ion battery at a heating temperature of less than 400 ° C. in the heating step. Here, by using a low oxygen gas such as a combustion gas (oxygen concentration 10% or less, preferably 5% or less) as the heating gas, it is possible to prevent ignition and explosion of the electrolytic solution and the like, and the large size of the heating device used in the heating process. The heat treatment can be facilitated, the efficiency of the heat treatment can be improved, and the heat treatment can be performed without disassembling a large waste lithium ion battery. Then, the waste lithium ion battery that has been heat-treated in the heating step is finely crushed in the crushing step, the positive electrode active material is sorted in the sorting step, and the positive electrode active material is heat-treated in the roasting step. The roasting equipment used in the process can be downsized, and heat consumption can be suppressed because extra items such as the outer case and current collector are not heated. Further, since the aluminum current collector that melts when the temperature is raised is removed before roasting, it is not necessary to set an upper limit of the roasting temperature.

Further, in the method for treating a waste lithium ion battery according to an aspect of the present invention, the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery. A crushing and sorting step of separating the positive electrode active material from the positive electrode current collector of the waste lithium ion battery and selecting the positive electrode active material while crushing the waste lithium ion battery heat-treated by the heating step and the heating step. A roasting step of heat-treating the positive electrode active material selected by the crushing and sorting step at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere is included.

According to this method, the electrolytic solution can be decomposed and removed and the electrolytic solution can be rendered harmless by heat-treating the waste lithium ion battery at a heating temperature of less than 400 ° C. in the heating step. Here, by using a low oxygen gas such as a combustion gas (oxygen concentration 10% or less, preferably 5% or less) as the heating gas, it is possible to prevent ignition and explosion of the electrolytic solution and the like, and the large size of the heating device used in the heating process. The heat treatment can be facilitated, the efficiency of the heat treatment can be improved, and the heat treatment can be performed without disassembling a large waste lithium ion battery. Then, the waste lithium ion battery that has been heat-treated in the heating step is finely crushed in the crushing and sorting step, the positive electrode active material is sorted, and the positive electrode active material is heat-treated in the roasting step. In addition to making it possible to reduce the size of the roasting equipment used in the above, heat consumption can be suppressed because extra items such as the outer case and current collector are not heated. Further, since the aluminum current collector that melts when the temperature is raised is removed before roasting, it is not necessary to set an upper limit of the roasting temperature.

The present invention has the configuration described above, makes it possible to improve the efficiency of heat treatment, and treats a waste lithium ion battery that can be heat treated without disassembling a large waste lithium ion battery. It has the effect of being able to provide a system and processing method.

FIG. 1 is a schematic diagram showing an outline of a treatment system for a waste lithium ion battery according to an example of the first embodiment. FIG. 2 is a schematic diagram showing an outline of a waste lithium ion battery processing system of an example of the second embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments.

(First Embodiment)
FIG. 1 is a schematic diagram showing an outline of a treatment system for a waste lithium ion battery according to an example of the first embodiment.

In the waste lithium ion battery processing system A, a large waste lithium ion battery (waste LIB), that is, a battery module in which a plurality of battery cells of the waste lithium ion battery are combined, and a plurality of battery modules are combined. It is intended for battery units. The battery unit is composed of, for example, a plurality of electrically connected battery modules, a control device, and a cooling device housed in a housing. In this processing system A, for example, a waste lithium ion battery mounted on an electric vehicle or a hybrid vehicle is removed, and the waste lithium ion battery (battery unit) in the removed state is processed without being disassembled. ..

This processing system A includes a supply device 1, a heating device 2, a crusher 3, and a roasting device 4.

The supply device 1 is composed of, for example, a conveyor. For example, when an operator sequentially places waste lithium ion batteries to be processed on a conveyor (supply device 1), the waste lithium ion batteries are sequentially conveyed in one direction by the transfer conveyor and sequentially supplied to the heating device 2 from the transfer end.

The heating device 2 is composed of a great preheater known in this example. The Great Preheater is a device body (housing) 20 in which a plurality of heat-resistant cast steel lattice plates 21 having a large number of slit-shaped holes are connected in a ring shape by an endless chain to rotate the endless chain. A mechanism for orbiting a plurality of lattice plates 21 is provided. As a result, the heating device 2 is configured to place the waste lithium ion battery supplied from the supply device 1 on the lattice plate 21 and transport it in one direction (direction of arrow a) and discharge it from the transport end. .. Then, the waste lithium ion battery to be transported is heated by the heating gas supplied from the outside to the inside of the apparatus main body 20.

The crusher 3 is composed of, for example, a roll crusher, and is configured to crush a large waste lithium ion battery (battery unit or battery module) to the size of a battery cell.

The heating device 2 and the crusher 3 are pretreatment facilities for the roasting device 4 in the subsequent stage.

In this example, the roasting apparatus 4 is composed of an externally heated rotary kiln. The externally heated rotary kiln includes a cylindrical body 41 that rotates about a central axis, and a heating jacket 42 that is provided so as to surround the outer periphery of the cylindrical body 41. The cylindrical body 41 has a reception port 41a at one end and a discharge port 41b at the other end, and is rotatably supported with an inclination of a predetermined angle so as to be downwardly inclined from the reception port 41a toward the discharge port 41b. It is configured to rotate around the center. The waste lithium ion battery supplied from the crusher 3 to the receiving port 41a of the cylindrical body 41 is transferred (conveyed) toward the discharge port 41b by the rotation of the cylindrical body 41. The inside of the cylindrical body 41 has a reducing atmosphere or a low oxygen atmosphere (oxygen concentration of 10% or less). Then, by supplying the heating gas to the heating jacket 42 that surrounds the outer periphery of the cylindrical body 41, the outer wall of the cylindrical body 41 is heated, and the waste lithium ion battery conveyed inside the cylindrical body 41 has a reducing atmosphere. It is heat-treated in a low oxygen atmosphere and discharged as a roasted product from the discharge port 41b.

The heating jacket 42 is provided with a heating gas supply port and a discharge port, and for example, a high temperature (for example, 550 ° C.) heating gas is sent from the hot air furnace from the supply port. Further, the heating gas discharged from the discharge port is supplied to the heating device 2. The heating device 2 is provided with a heating gas supply port and a heating gas discharge port in the device main body 20. The heating gas discharged from the heating jacket 42 is cooled as necessary so as to reach a predetermined temperature (for example, 200 ° C.), and then is supplied from the supply port of the heating device 2 to the inside thereof. Then, the gas discharged from the discharge port of the heating device 2 is sent to the exhaust gas treatment facility for treatment. In this way, energy saving can be achieved by using the exhaust gas of the roasting device 4 in the heating device 2.

Next, the flow of processing of the waste lithium ion battery by this processing system A will be described. For example, a worker sequentially supplies a large-sized waste lithium-ion battery including a battery unit or a battery module to the supply device 1. The supply device 1 conveys the supplied waste lithium ion battery in one direction and supplies it to the heating device 2.

In the heating device 2, the waste lithium ion battery is heat-treated with a heating gas at about 200 ° C. while being conveyed in one direction. As a result, the electrolytic solution contained in the waste lithium ion battery can be decomposed and removed, and the electrolytic solution can be rendered harmless. By performing the heat treatment in the heating device 2 in a low oxygen atmosphere (oxygen concentration of 10% or less, preferably 5% or less), ignition and explosion of the electrolytic solution can be prevented. Further, a device such as a great preheater can be used as the heating device 2, and the size of the heating device 2 can be easily increased.

Then, the waste lithium ion battery in which the electrolytic solution is detoxified by the heating device 2 is supplied to the crusher 3, crushed to the size of a battery cell by the crusher 3, and then supplied to the roasting device 4. ..

The waste lithium ion battery supplied to the receiving port 41a of the roasting apparatus 4 is heat-treated while being conveyed toward the discharge port 41b by rotating the cylindrical body 41 to become a roasted product, which is discharged from the discharge port 41b. To. In the roasting apparatus 4, in order to facilitate recovery of useful metals such as cobalt in the subsequent process, it is necessary to set the temperature at which organic substances such as separators and binders can be decomposed (for example, 400 ° C. or higher). On the other hand, it is necessary to set the temperature at which the aluminum used for the positive electrode material does not melt, that is, the temperature lower than the melting point of aluminum (660 ° C.). Therefore, the heating temperature may be 400 ° C. or higher and lower than the melting point of aluminum (660 ° C.).

The roasted product discharged from the roasting apparatus 4 is further crushed and then subjected to processing such as sorting to extract useful metals such as copper, aluminum, cobalt, nickel, manganese, and lithium.

In the waste lithium ion battery processing system A of the present embodiment, the waste lithium ion battery is used in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery before the waste lithium ion battery is heat-treated at 400 ° C. or higher. It is provided with a heating device 2 that performs heat treatment at a heating temperature of less than 400 ° C. By heat-treating the waste lithium ion battery at a heating temperature of less than 400 ° C. by the heating device 2, the electrolytic solution can be decomposed and removed and the electrolytic solution can be rendered harmless. Here, by using a low oxygen gas as the heating gas, ignition / explosion of the electrolytic solution or the like can be prevented, and a device such as a great preheater can be used as the heating device 2, so that the heating device 2 can be easily enlarged. Therefore, the efficiency of the heat treatment can be improved, and the heat treatment can be performed without disassembling the large waste lithium ion battery.

In the heating device 2, it is necessary to set the heating temperature to 150 ° C. or higher in order to decompose and remove the electrolytic solution. Therefore, the heating temperature by the heating device 2 may be 150 ° C. or higher and lower than 400 ° C., and may be 150 ° C. or higher and 250 ° C. or lower.

Here, by using the Great Preheater as the heating device 2, the heat treatment can be continuously performed while transporting the waste lithium ion battery, so that the efficiency of the heat treatment can be improved.

Further, the waste lithium ion battery after the electrolytic solution is decomposed and removed (detoxified) by the heating device 2 is crushed by the crusher 3 to ensure safety and crush.

Next, in the roasting apparatus 4, heat treatment is performed at 400 ° C. or higher and lower than 660 ° C., but since the waste lithium ion battery crushed by the crusher 3 and reduced in size is heat-treated. , Heat exchangeability is improved, and processing time can be shortened. In addition, the roasting apparatus 4 can be downsized.

Here, by using an externally heated rotary kiln as the roasting apparatus 4, the waste lithium ion battery can be continuously received and discharged, so that the efficiency of the heat treatment can be improved.

The method for treating the waste lithium ion battery by the processing system A shown in FIG. 1 includes a heating step by the heating device 2, a crushing step by the crusher 3, and a roasting step by the roasting device 4.

In the processing system A of the first embodiment, the battery module and the battery unit have been described as the processing target, but the battery cell of the waste lithium ion battery can also be the processing target.

(Second Embodiment)
FIG. 2 is a schematic diagram showing an outline of a waste lithium ion battery processing system of an example of the second embodiment. In FIG. 2, elements that are the same as or correspond to those in FIG. 1 may be designated by the same reference numerals, and duplicate description thereof may be omitted.

In the second embodiment, the treatment system B of the waste lithium ion battery shown in FIG. 2 is used to improve the recovery rate of lithium contained in the positive electrode active material among the useful metals extracted from the roasted product. The possible configurations are also described. The waste lithium ion battery is composed of an exterior material serving as a battery case, a positive electrode material, a negative electrode material, an electrolytic solution, a separator and the like. The positive electrode material is formed by fixing the positive electrode active material to a positive electrode current collector (for example, an aluminum foil) with a binder. As the positive electrode active material, an oxide containing lithium is used. The negative electrode material is formed by fixing a negative electrode active material such as graphite to a negative electrode current collector (for example, copper foil) with a binder. As the binder, a resin such as PTFE or PVDF is used.

The processing system B shown in FIG. 2 includes a supply device 1, a heating device 2, a crusher 3, a sorter 5, and a roasting device 4. Here, the supply device 1, the heating device 2, the crusher 3, and the roasting device 4 can be configured by using the same ones as in FIG. However, the crusher 3 can be configured by, for example, a roll crusher as in the case of FIG. 1, but in the case of FIG. 1, a large waste lithium ion battery (battery unit or battery module) is about the size of a battery cell. It was supposed to be crushed to a size, but in the case of FIG. 2, it is configured so that it can be crushed to a size smaller than that of the battery cell.

The sorter 5 is configured so that the positive electrode active material can be separated from the positive electrode current collector and the positive electrode active material can be sorted and taken out from the waste lithium ion battery crushed by the crusher 3. As the sorter 5, for example, a sieve shaker in which a plurality of alumina balls having a diameter of about 20 to 30 mm are placed on a sieve having an appropriate spread (for example, a spread of about several mm) can be used. By using the alumina balls in this way, the vibrating alumina balls partially give a large number of impacts to the positive electrode material and the negative electrode material, and promote the separation (separation) of the active material from the positive electrode and negative electrode current collectors. The finely divided positive electrode and negative electrode active materials can be dropped under the sieve. Therefore, in reality, not only the positive electrode active material but also the negative electrode active material (including a small amount of impurities other than the active material) is taken out under the sieve by the sorting machine 5 and supplied to the roasting apparatus 4, and the waste lithium other than these is discharged. The exterior material of the ion battery, the current collector, etc. are sent to another processing facility (not shown).

The supply of the active material or the like from the sorter 5 to the roasting apparatus 4 can be configured to be performed, for example, via a rotary feeder. Further, the supply of the roasted product from the roasting apparatus 4 to the useful metal extraction apparatus can be configured to be performed, for example, via a double flap damper.

In the present embodiment, since the positive electrode active material and the negative electrode active material are mainly supplied to the roasting apparatus 4, the roasting apparatus 4 can be miniaturized. Further, since the current collector (aluminum foil or the like) is not supplied to the roasting apparatus 4, the heat treatment can be performed without considering the embrittlement of the current collector.

Next, the flow of processing of the waste lithium ion battery by this processing system B will be described. The processing system B can process not only a large-sized waste lithium-ion battery composed of a battery unit or a battery module but also a battery cell. For example, a waste lithium ion battery including a battery cell, a battery unit, or a battery module is sequentially supplied to the supply device 1 by an operator. The supply device 1 conveys the supplied waste lithium ion battery in one direction and supplies it to the heating device 2.

In the heating device 2, the waste lithium ion battery is heat-treated with a heating gas at a heating temperature of 150 ° C. or higher and lower than 400 ° C. while being conveyed in one direction. As a result, the electrolytic solution contained in the waste lithium ion battery can be decomposed and removed, and the electrolytic solution can be rendered harmless. By performing the heat treatment in the heating device 2 in a low oxygen atmosphere (oxygen concentration of 10% or less, preferably 5% or less), ignition and explosion of the electrolytic solution can be prevented.

Then, the waste lithium ion battery in which the electrolytic solution is detoxified by the heating device 2 is supplied to the crusher 3, crushed by the crusher 3 to a size smaller than the battery cell, and then supplied to the sorter 5. .. Then, the sorting machine 5 sorts the positive electrode active material and the negative electrode active material as described above, and these are supplied to the roasting apparatus 4.

The positive electrode active material and the negative electrode active material supplied to the receiving port 41a of the roasting apparatus 4 are heat-treated while being conveyed toward the discharge port 41b by the rotation of the cylindrical body 41 to become a roasted product, and become a roasted product. Is discharged from. The roasting apparatus 4 here is configured to perform heat treatment at a heating temperature of 500 ° C. or higher in a reducing atmosphere (for example, CO concentration 1%) or a low oxygen atmosphere (for example, O ₂ concentration 1 to 5%). ..

The roasted product discharged from the roasting apparatus 4 is supplied to a useful metal extraction facility that extracts useful metals such as lithium, and useful metals such as lithium are extracted (recovered).

[Lithium elution test]
A roasted product was produced using a test apparatus simulating this processing system B, and a lithium elution test was conducted in which lithium was eluted from the roasted product.

Further, here, regarding the case where the roasting conditions (internal atmosphere and heating temperature in the roasting apparatus 4) are changed for each of the two types (NCM type and LFP type) of the lithium ion batteries to be processed. Lithium elution test was performed. In this lithium elution test, a magnetic stirrer is used to immerse the roasted product in a container filled with water, stir, and add sulfuric acid as appropriate to adjust the pH (hydrogen ion index) to generate a lithium eluate. did. Further, in the case of both the NCM type and the LFP type batteries, the heating condition in the heating device 2 was a low oxygen gas (O ₂ concentration 5%) as an atmospheric gas and a heating temperature of 250 ° C.

The NCM-based battery is a battery containing lithium, nickel, cobalt, and manganese in the positive electrode active material. The LFP-based battery is a battery containing lithium, iron, and phosphorus in the positive electrode active material. In both batteries, aluminum foil is used for the positive electrode current collector, graphite is used for the negative electrode active material, and copper foil is used for the negative electrode current collector.

[Lithium elution test results]
For battery NCM system, the dissolution rate of lithium for roasted roasted product at a heating temperature of 570 ° C. in a low oxygen atmosphere (O ₂ concentration of 1%) was 55%. On the other hand, the elution rate of lithium for the roasted product roasted at a heating temperature of 570 ° C. in a reducing atmosphere (CO concentration 1%) was 85%.

As described above, in the case of NCM-based batteries, a higher elution rate was obtained when roasting in a reducing atmosphere than when roasting in a low oxygen atmosphere. The same test was conducted on the roasted product when the heating temperature was 520 ° C., but a higher elution rate was obtained when the heating temperature was raised. It is considered that this is because when the heating temperature is raised in the reducing atmosphere, the reaction between the positive electrode active material and CO proceeds, and the positive electrode active material changes to a form in which lithium is relatively easily dissolved in water.

Also, if the battery LFP system, the dissolution rate of lithium for roasted roasted product at a heating temperature of 570 ° C. in a low oxygen atmosphere (O ₂ concentration of 1%) was 28%. On the other hand, the elution rate of lithium for the roasted product roasted at a heating temperature of 570 ° C. in a reducing atmosphere (CO concentration 1%) was 9%.

As described above, in the case of the LFP-based battery, a higher elution rate was obtained when roasting in a low oxygen atmosphere than when roasting in a reducing atmosphere. The same test was conducted on the roasted product when the heating temperature was 520 ° C., but a higher elution rate was obtained when the heating temperature was raised. It is considered that this is because when the heating temperature is raised in a low oxygen atmosphere, the reaction between the positive electrode active material and oxygen proceeds, and the positive electrode active material changes to a form in which lithium is relatively easily dissolved in water.

As described above, in the case of NCM type batteries, roasting in a reducing atmosphere is suitable for recovering lithium, and in the case of LFP type batteries, roasting in a low oxygen atmosphere is suitable. ing. Further, in any case, the heating temperature is preferably 500 ° C. or higher, more preferably 550 ° C. or higher.

In the waste lithium ion battery treatment system B of the present embodiment, the effect of providing the waste lithium ion battery with the heating device 2 for heat treatment of less than 400 ° C. is the same as in the case of the treatment system A of the first embodiment. Is.

In the present embodiment, the waste lithium ion battery that has been heat-treated by the heating device 2 is finely crushed by the crusher 3, the active material is taken out by the sorting machine 5, and the battery is roasted by the roasting device 4. The roasting apparatus 4 can be made smaller and the heat consumption of the roasting apparatus 4 can be suppressed. Further, since the aluminum current collector that melts when the temperature is raised is removed before roasting, it is not necessary to set an upper limit of the roasting temperature.

Further, when the waste lithium ion battery is an NCM type battery, the lithium recovery rate can be improved when the lithium is recovered in the subsequent process by roasting in the reducing atmosphere in the roasting apparatus 4. Further, when the waste lithium ion battery is an LFP type battery, the lithium recovery rate can be improved when the lithium is recovered in the subsequent process by roasting in the roasting apparatus 4 in a low oxygen atmosphere.

The method for treating the waste lithium ion battery by the processing system B shown in FIG. 2 includes a heating step by the heating device 2, a crushing step by the crusher 3, a sorting step by the sorting machine 5, and a roasting step by the roasting device 4. Includes.

Further, in the processing system B shown in FIG. 2, a crushing and sorting machine 6 may be used instead of the crushing machine 3 and the sorting machine 5. The crushing and sorting machine 6 is configured to separate the positive electrode active material from the positive electrode current collector of the waste lithium ion battery and take out the positive electrode active material while crushing the waste lithium ion battery heat-treated by the heating device 2. For example, it can be configured by using a device such as a striking type or shear type crusher equipped with a lattice. Actually, not only the positive electrode active material but also the negative electrode active material and the like are taken out by the crushing and sorting machine 6 and supplied to the roasting apparatus 4. The method for treating the waste lithium ion battery in this case includes a heating step by the heating device 2, a crushing and sorting step by the crushing and sorting machine 6, and a roasting step by the roasting device 4.

From the above description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed only as an example and is provided for the purpose of teaching those skilled in the art the best aspects of carrying out the present invention. The details of its structure and / or function can be substantially changed without departing from the spirit of the present invention.

INDUSTRIAL APPLICABILITY The present invention is useful as a treatment system and a treatment method for waste lithium ion batteries, which can improve the efficiency of heat treatment and can heat treatment without disassembling a large waste lithium ion battery. ..

A, B Waste lithium-ion battery processing system 1 Supply device 2 Heating device 3 Crusher 4 Roasting device 5 Sorter 6 Crush sorter

Claims (12)

The waste lithium ion battery is provided with a heating device that heat-treats the waste lithium ion battery at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery.
Waste lithium-ion battery processing system. The heating temperature of the waste lithium ion battery by the heating device is 150 ° C. or higher and 250 ° C. or lower.
The waste lithium ion battery processing system according to claim 1. The heating device is
It is composed of a great preheater that heat-treats while transporting the waste lithium-ion battery in one direction.
The waste lithium ion battery processing system according to claim 1 or 2. A crusher for crushing the waste lithium ion battery heat-treated by the heating device is further provided.
The waste lithium ion battery processing system according to any one of claims 1 to 3. The waste lithium ion battery crushed by the crusher is further provided with a roasting apparatus that heat-treats the waste lithium ion battery at a heating temperature of 400 ° C. or higher and lower than 660 ° C. in a reducing atmosphere or a low oxygen atmosphere.
The waste lithium ion battery processing system according to claim 4. The roasting device
The cylindrical body has a cylindrical body whose outer wall is heated with a reducing atmosphere or a low oxygen atmosphere inside, and by rotating the cylindrical body, a waste lithium ion battery received from an inlet at one end of the cylindrical body is received. It is composed of an externally heated rotary kiln that conveys the inside of the cylinder toward the discharge port at the other end of the cylinder and discharges it from the discharge port.
The waste lithium ion battery processing system according to claim 5. A crusher for crushing the waste lithium ion battery heat-treated by the heating device, and
A sorter that separates the positive electrode active material from the positive electrode current collector and sorts the positive electrode active material from the waste lithium ion battery crushed by the crusher.
A roasting apparatus for heat-treating the positive electrode active material sorted by the sorter at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere is further provided.
The waste lithium ion battery processing system according to any one of claims 1 to 3. A crushing sorter that separates the positive electrode active material from the positive electrode current collector of the waste lithium ion battery and sorts the positive electrode active material while crushing the waste lithium ion battery heat-treated by the heating device.
The positive electrode active material sorted by the crushing sorter is further provided with a roasting apparatus that heat-treats the positive electrode active material at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere.
The waste lithium ion battery processing system according to any one of claims 1 to 3. The roasting device
When the waste lithium ion battery contains lithium, nickel, cobalt and manganese in the positive electrode active material, it is configured to perform heat treatment in a reducing atmosphere.
When the waste lithium ion battery contains lithium, iron and phosphorus in the positive electrode active material, it is configured to perform heat treatment in a low oxygen atmosphere.
The waste lithium ion battery processing system according to claim 7 or 8. A heating step in which the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery.
A crushing step of crushing the waste lithium ion battery heat-treated by the heating step, and
The waste lithium ion battery crushed by the crushing step includes a roasting step of performing a heat treatment at a heating temperature of 400 ° C. or higher and lower than 660 ° C. in a reducing atmosphere or a low oxygen atmosphere.
How to dispose of waste lithium-ion batteries. A heating step in which the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery.
A crushing step of crushing the waste lithium ion battery heat-treated by the heating step, and
A sorting step of separating the positive electrode active material from the positive electrode current collector and selecting the positive electrode active material from the waste lithium ion battery crushed by the crushing step.
A roasting step of heat-treating the positive electrode active material selected by the sorting step at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere is included.
How to dispose of waste lithium-ion batteries. A heating step in which the waste lithium ion battery is heat-treated at a heating temperature of less than 400 ° C. in order to decompose and remove the electrolytic solution contained in the waste lithium ion battery.
A crushing and sorting step of separating the positive electrode active material from the positive electrode current collector of the waste lithium ion battery and selecting the positive electrode active material while crushing the waste lithium ion battery heat-treated by the heating step.
A roasting step of heat-treating the positive electrode active material selected by the crushing and sorting step at a heating temperature of 500 ° C. or higher in a reducing atmosphere or a low oxygen atmosphere is included.
How to dispose of waste lithium-ion batteries.

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