JP7179559B2 - Apparatus and method for treating waste lithium-ion batteries - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus and method for treating waste lithium-ion batteries used as power sources for electric vehicles, hybrid vehicles, and the like.

A lithium-ion battery consists of a positive electrode material in which lithium, cobalt, nickel or the like is applied to an aluminum foil, a negative electrode material in which a copper foil is applied with graphite or the like, an electrolyte, a separator, and the like. Since lithium-ion batteries contain valuables such as lithium, cobalt, nickel, copper, and aluminum, recovering these valuables from discarded lithium batteries is extremely beneficial for our resource-poor country. Therefore, in order to recover the above-mentioned valuables from waste lithium ion batteries, separation and recovery by roasting, crushing or pulverization, sieving, sorting, and the like are performed.

However, the electrolyte of a lithium ion battery contains a fluorine compound (such as LiPF ₆ ) as an electrolyte, and when LiPF ₆ reacts with water, it hydrolyzes to generate toxic hydrogen fluoride. Therefore, when processing waste lithium-ion batteries, in order to safely treat volatile fluorine compounds (such as LiPF ₆ ), etc., in Patent Document 1, the volatile components of the electrolyte solution containing fluorine compounds are heated under reduced pressure. and a fluorine-fixing step of reacting the fluorine component contained in the vaporized gas with calcium to fix it as calcium fluoride.

On the other hand, in Patent Document 2, after storing a battery pack in which a plurality of battery modules in which a plurality of lithium ion battery cells are arranged are housed in a box-shaped housing in a heat-resistant container provided with an exhaust port, the heat-resistant container is put into a heat treatment furnace and the heat-resistant container is heated from the outside at a temperature lower than the melting point of aluminum, so that the battery pack in the heat-resistant container is dry distilled to separate the carbonized mixture, and the electrolyte in the battery is volatilized. Disclosed is a method for recycling waste lithium-ion batteries with extremely simple work by discharging the waste lithium ion batteries into a heat treatment furnace through an exhaust port of a heat-resistant container.

JP 2013-229326 A JP 2016-22395 A

However, after heat treatment by the techniques described in Patent Documents 1 and 2, if natural cooling is performed in the atmosphere, harmful gases containing hydrogen fluoride, hydrogen chloride, etc., are emitted from the heated waste lithium-ion batteries. There is still a safety issue because there is a possibility that In addition, the natural cooling takes a long time, which hinders efficient processing.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-described problems in the prior art, and an object of the present invention is to treat waste lithium ion batteries safely and efficiently.

In order to achieve the above object, the present invention provides an apparatus for treating waste lithium ion batteries, comprising: a heat-resistant container for containing the waste lithium-ion batteries; a heat treatment furnace for heating the heat-resistant container; and a cooling device for cooling the heat-resistant container discharged from the heat treatment furnace by the container conveying device by spraying cooling water.

According to the present invention, the heat-resistant container discharged from the heat treatment furnace can be sprayed with cooling water by the cooling device to cool the waste lithium ion batteries after the heat treatment in a short time, and the waste lithium ion batteries can be efficiently treated. can do.

The apparatus for treating waste lithium ion batteries can be provided with a pressure control device for controlling the inside of the cooling device to have a negative pressure, whereby harmful gases including hydrogen fluoride, hydrogen chloride, etc. can be prevented from being released.

Further, an exhaust gas treatment device for supplying exhaust gas from the cooling device to an exhaust gas treatment system of the cement kiln can be provided, whereby harmful gases including hydrogen fluoride, hydrogen chloride, etc. are fixed to the cement raw material in the cement manufacturing process. can be rendered harmless.

Furthermore, the present invention is a method for treating waste lithium-ion batteries, characterized by heating a heat-resistant container containing waste lithium-ion batteries and cooling only the heat-resistant container after heating by spraying cooling water. . According to the present invention, it is possible to cool the heat-treated waste lithium-ion batteries in a short time by spraying cooling water only on the heat-resistant container after heating, and to efficiently treat the waste lithium-ion batteries.

As described above, according to the present invention, waste lithium ion batteries can be treated safely and efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall cross-sectional view showing an embodiment of a waste lithium ion battery processing apparatus according to the present invention; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an overall vertical cross-sectional view showing an embodiment of a waste lithium ion battery processing apparatus according to the present invention; FIG. 3 is a view in the direction of arrow A in FIG. 2 and is a schematic diagram showing a cooling device and its vicinity. 1 is a vertical cross-sectional view showing a heat-resistant container used in a waste lithium-ion battery processing apparatus according to the present invention. FIG. FIG. 4 is a cross-sectional view showing the heat-resistant container just before it is put into the heat treatment furnace; It is a vertical cross-sectional view showing a heat-resistant container immediately before being put into a heat treatment furnace. It is the schematic for demonstrating the injection|throwing-in operation|movement of the heat-resistant container to a heat treatment furnace. It is the schematic for demonstrating the injection|throwing-in and discharge operation|movement of the heat-resistant container to a heat treatment furnace. It is the schematic for demonstrating the injection|throwing-in and discharge operation|movement of the heat-resistant container to a heat treatment furnace. It is the schematic for demonstrating the injection|throwing-in operation|movement of the heat-resistant container to a cooling device and a heat treatment furnace, and discharge|emission. It is a schematic diagram for explaining the discharge operation of the heat-resistant container from the cooling device.

An embodiment of the present invention will now be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, the waste lithium ion battery processing apparatus 1 according to the present invention includes a battery pack 50 in which a plurality of battery modules each having a plurality of lithium ion battery cells arranged therein are housed in a box-shaped housing. A plurality of heat-resistant containers 2 that mainly store battery packs 50, a heat treatment furnace 3, and a container transporter that puts the heat-resistant containers 2 into and out of the heat treatment furnace 3. A device 4 and a cooling device 31 for cooling the heat-resistant container 2 after heat treatment are provided.

The heat-resistant container 2, as shown in FIGS. 4 to 6, is composed of a container body 2A and a lid 2B, and has a heat-resistant temperature of at least 650.degree.

The container main body 2A includes an inner cylinder 2a formed in a cylindrical shape with an upward opening, an outer cylinder 2b having a larger diameter than the inner cylinder 2a and arranged so as to surround the inner cylinder 2a, the inner cylinder 2a and the outer cylinder 2a. It is composed of a plurality of wheels 2c arranged on the bottom surface of the cylinder 2b, two handles 2e fixed to the peripheral surface 2d of the outer cylinder 2b, and a hanger 2f protruding from the peripheral surface 2d of the outer cylinder 2b.

On the other hand, the lid 2B includes a cylindrical main body 2n that opens downward, an exhaust pipe 2g that opens in the peripheral surface of the main body 2n and protrudes obliquely upward, and a handle provided on the ceiling surface 2h of the main body 2n. 2m.

As shown in FIGS. 1 and 2, the heat treatment furnace 3 is a cylindrical vertical furnace and is heated by four gas burners 8 (8A-8D). Nozzles 11 (11A to 11D) are provided near the gas burner 8, and combustion and cooling air A is supplied into the furnace via a fan (not shown). A hearth 17 of the heat treatment furnace 3 is rotated about a vertical axis by a hearth rotating device 19 equipped with an electric motor (not shown) and positioned at a predetermined position by a positioning sensor (not shown). A secondary combustion chamber, an exhaust chimney, etc. are provided downstream of the exhaust pipe 28.

A part of the furnace wall 7 of the heat treatment furnace 3 is formed with an opening 7a separated from the outside by a vertically openable furnace body door 7b. At a position facing the opening 7a, a container conveying device 4 is provided for inserting the heat-resistant container 2 into the heat treatment furnace 3 from the opening 7a and for discharging the heat-resistant container 2 after going around the inside of the heat treatment furnace 3 from the heat treatment furnace 3. be provided.

As shown in FIGS. 1, 2 and 6, the container conveying device 4 extends in the direction of the line connecting the opening 7a of the heat treatment furnace 3 and the center of the heat treatment furnace 3 (horizontal direction in FIG. 1). forward rotation of the heat-resistant container 2 to push the heat-resistant container 2 into the heat treatment furnace 3, and a claw 4c for locking the hanger 2f provided on the outer periphery of the container body 2A of the heat-resistant container 2. , and has a pull-out portion 4 b for pulling out the heat-resistant container 2 from the heat treatment furnace 3 by negative rotation of the motor 18 . The pusher portion 4a is arranged directly above the pullout portion 4b.

A furnace front chamber 23 is provided adjacent to the openable furnace door 7b (left side in FIG. 1), and a cooling device 31 is provided adjacent to the furnace front chamber 23 (right side in FIG. 3). . A slide base 21 is installed in the tangential direction of the heat treatment furnace 3 (vertical direction in FIG. 1) and is movable by a conveying device 29. The slide base 21, in FIG. It is configured to be movable between the furnace front chamber 23 and the cooling device 31 with the doors 24 and 25 separated.

The cooling device 31 is adjacent to the furnace front chamber 23 across an openable door 25, and includes spray devices 31a to 31c for spraying cooling water to the heat-resistant container 2 discharged from the heat treatment furnace 3. . The spray device 31 a sprays cooling water onto the ceiling of the heat-resistant container 2 , and the spray devices 31 b and 31 c spray cooling water onto the sides of the heat-resistant container 2 . Also, a drain port 31d is formed in the bottom surface of the cooling device 31 for collecting water after spraying.

In addition, a pressure control device is provided to control the inside of the cooling device 31 to have a negative pressure. A suction device and a controller or the like for controlling the suction device so that the measured value of the pressure gauge becomes a negative pressure are provided. Further, an exhaust gas treatment device (not shown) is provided for supplying the exhaust gas from the cooling device 31 to an exhaust gas treatment system of the cement kiln.

Next, a method for processing waste lithium ion batteries using the waste lithium ion battery processing apparatus 1 having the above configuration will be described. In the following description, a case where the processing device 1 processes the battery pack 50 that has been removed from a hybrid vehicle, an electric vehicle, or the like will be exemplified.

The temperature inside the heat treatment furnace 3 is raised to 650° C., and a crane or the like (not shown) is used to move the heat-resistant container 2N containing the battery pack 50 to the right end of the slide base 21 as shown in FIG. Place. After opening the door 24, the slide base 21 is moved to the right via the transfer device 29, the heat-resistant container 2 is moved to the front of the furnace door 7b, and then the door 24 is closed to open the furnace door 7b. Then, the pusher portion 4a of the container conveying device 4 is advanced to load the heat-resistant container 2N into the heat treatment furnace 3. As shown in FIG. As a result, the heat-resistant container 2N is placed on the hearth 17 of the heat treatment furnace 3, at the 9 o'clock position in FIG.

After retracting the pusher portion 4a of the container transfer device 4, the furnace door 7b is closed, and the hearth 17 is rotated counterclockwise by 45° via the hearth rotating device 19. As shown in FIG. This 45° rotation is not particularly limited, but for example, the hearth 17 is set to rotate once every 5 hours by rotating the hearth 17 by 45° every 37.5 minutes. ing.

By repeating the above operation seven times, on the hearth 17 of the heat treatment furnace 3, as shown in FIG. is placed on

During the above operation, the heat-resistant container 2 is heated from the outside while making one revolution in the heat treatment furnace 3, so that the inside of the heat-resistant container 2 becomes a reducing atmosphere, and the battery pack 50 stored in the heat-resistant container 2 is made of resin. Plastics such as the housing are in a state of being separated from materials containing useful metals such as lithium, cobalt, nickel and manganese as a carbonized mixture by dry distillation. Since the heat-resistant container 2 is heated at a temperature (650° C.) lower than the melting point (660° C.) of aluminum, the aluminum component used in the battery pack 50 does not melt. Further, the electrolyte in the battery volatilizes and is discharged into the heat treatment furnace 3 through the exhaust pipe 2g of the heat-resistant container 2 together with gas generated by thermal decomposition of combustible substances such as plastics. The unburned gas in the heat treatment furnace 3 is led to the secondary combustion chamber and burned at a temperature (800° C.) higher than the temperature of the heat treatment furnace 3 (650° C.).

Before the heat-resistant container 2 makes one turn in the heat treatment furnace 3, as shown in FIG. 23. At this time, the door 24 is closed.

When the heat-resistant container 2 makes one turn in the heat treatment furnace 3, the furnace door 7b is opened to advance the pull-out portion 4b of the container transfer device 4 to the position of the heat-resistant container 2, and as shown in FIG. A hook 4c provided on the heat-resistant container 2 is engaged with a hanger 2f provided on the heat-resistant container 2. As shown in FIG. Then, the pull-out portion 4b is retracted, and as shown in FIG. 9, the heat-resistant container 2T after heat treatment is pulled out from the heat treatment furnace 3 and placed on the slide base 21, and the furnace body door 7b is closed.

Next, after the doors 24 and 25 are opened, the slide base 21 is moved to the right to move the new heat-resistant container 2N containing the battery pack 50 to the front of the furnace door 7b. 2T is moved to the cooling device 31 and the doors 24 and 25 are closed. This state is shown in FIG.

From the state of FIG. 10, a new heat-resistant container 2N is put into the heat treatment furnace 3 in the manner described above and heated, and the heat-treated heat-resistant container 2T is cooled by the cooling device 31. In the cooling device 31, the spray device 31a sprays cooling water onto the ceiling of the heat-resistant container 2T, and the spray devices 31b and 31c spray cooling water onto the side surfaces of the heat-resistant container 2T. The water after spraying is recovered from the drain port 31d. With conventional natural cooling, it takes about 6 hours to cool the battery pack 50 heated to about 650° C. to about 150° C., but with cooling by this cooling water spray, it takes about 1 hour, that is, one-sixth of the conventional cooling time. The cooling process is completed in about. Moreover, even if the battery pack weight or the heating temperature changes, the cooling process can be shortened by adjusting the amount of sprayed water.

Next, after opening the doors 24 and 25, the slide base 21 on which the cooled heat-resistant container 2C is placed is moved to the left and conveyed to the next process by a crane or the like.

In the heat-treated heat-resistant container 2C after cooling, the battery pack 50 inside is crushed and classified to remove the carbonized mixture, and then useful metals such as lithium, cobalt, nickel, and manganese are further separated. Further, the crushed material of the battery pack 50 is subjected to a magnetic separator to separate magnetic substances such as iron casings and screws from Mik-Metal consisting of copper and aluminum. After separating into foil and aluminum foil laminate, it can be further separated into copper foil and aluminum foil by a sorter.

Harmful gases containing hydrogen fluoride, hydrogen chloride, etc. from the cooling device 31 are supplied to the exhaust gas treatment system of the cement kiln by the exhaust gas treatment device, and are fixed in cement raw materials in the cement manufacturing process to render them harmless.

The heat treatment furnace 3 does not have to have a rotating hearth 17, and a batch type furnace is also applicable. Various furnaces using electricity or heavy oil can also be used as heat sources, and exhaust gas from existing manufacturing facilities, for example, cement baking equipment, can be used as heat sources.

In the present embodiment, the battery pack 50 is heat-treated as it is without removing the battery cells individually. The heat-resistant container 2 containing the removed items may be placed in the heat treatment furnace 3 for heat treatment.

1 waste lithium ion battery processing device 2 heat-resistant container 3 heat treatment furnace 4 container transport device 7 furnace wall 8 (8A to 8D) gas burner 11 (11A to 11D) nozzle 17 hearth 18 motor 19 hearth rotating device 21 slide base 23 Front chambers 24, 25 Door 29 Transfer device 31 Cooling device 50 Battery pack

Claims (4)

a heat-resistant container for housing waste lithium-ion batteries;
a heat treatment furnace for heating the heat-resistant container;
a container conveying device for loading and unloading the heat-resistant container into and from the heat treatment furnace;
and a cooling device for cooling the heat-resistant container discharged from the heat treatment furnace by the container conveying device by spraying cooling water. 2. The apparatus for treating waste lithium ion batteries according to claim 1, further comprising a pressure control device for controlling the inside of said cooling device to have a negative pressure. 3. The apparatus for treating waste lithium ion batteries according to claim 1, further comprising an exhaust gas treatment device for supplying exhaust gas from said cooling device to an exhaust gas treatment system of a cement kiln. Heat the heat-resistant container containing the waste lithium-ion battery,
A method for treating waste lithium-ion batteries, comprising spraying cooling water only on the heat-resistant container after heating to cool the container.

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