JP4358489B2 - Method for recovering valuable materials from waste secondary batteries - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a battery content having a structure in which a positive electrode plate, a negative electrode plate, and a separator are wound, an outer can that contains the battery content, and a lid that seals the outer can. The present invention relates to a valuable resource recovery method capable of efficiently recovering valuable resources from a waste secondary battery provided with an annular caulking portion that connects and fixes an outer can and a lid.
[0002]
[Prior art]
With the widespread use of portable electronic devices such as personal computers, digital cameras, video cameras, and mobile phones, or transportation means such as electric cars, hybrid cars, and bicycles with electric motors, the demand for various types of batteries as driving power sources has increased. Yes. Known batteries include primary batteries such as manganese dry batteries, alkaline manganese dry batteries, and lithium batteries, and secondary batteries such as nickel-cadmium batteries, nickel-hydrogen batteries, and lithium ion batteries. These battery electrode materials contain a lot of expensive metals such as nickel, cobalt, and rare earth metals, and it is important to collect and reuse these valuable metals from the viewpoint of resources and pollution prevention. It is.
By the way, as a form of the various batteries, a form of a box containing battery contents in a plastic box, a dry battery form using a metal thin plate as an outer can, a button battery form, and the like are known.
Conventionally, as a method for recovering valuable materials from the plastic box-shaped battery, the lid portion and the box portion of the box body of such a waste battery are horizontally cut and separated, and the battery contents are removed. Thereafter, a method of separating the negative electrode plate, the positive electrode plate, and the separator has been proposed (Japanese Patent No. 3183619).
When such a method is carried out in a dry battery adopting a metal thin plate exhibiting malleability in an outer can, that is, in order to separate the lid or bottom of the outer can of the waste dry battery, When the battery contents are to be removed by cutting in a parallel horizontal direction and separating the portion having the lid surface or bottom surface, the outer can edge of the cut portion is bent inward, and the battery internal material is cut into the cut portion. Since it is caught, it becomes difficult to remove, and there is a problem that the battery contents cannot be removed industrially.
Therefore, as a method for recovering valuable materials from such waste dry batteries, the waste dry batteries are crushed together with the cans, and by means of wind sorting, sieving, specific gravity difference separation, etc., from the outer cans, current collectors, etc. A method has been proposed in which a mixed active material of a negative electrode is separated, and further, a positive electrode active material and a negative electrode active material are separated and recovered by specific gravity difference separation.
However, it is difficult to separate and recover the positive electrode active material and the negative electrode active material with high purity from the mixed active material of the positive electrode and the negative electrode in the method of crushing the waste dry battery together with the can, and the process is complicated and efficient. There is a problem that is low.
Further, the dry battery is usually provided with an annular caulking portion for connecting and fixing the outer can and the lid portion for containing the battery contents and sealing the outer can. Since the caulking part is difficult to disassemble, it is considered that valuable materials cannot be recovered unless a method of crushing the waste dry battery together with the can body is employed.
[0003]
[Problems to be solved by the invention]
The object of the present invention is to dismantle the outer can of the waste secondary battery in one substantially simple process without adopting a method of crushing the waste dry battery together with the can, and easily From the secondary battery, which can easily separate and recover the positive electrode and the negative electrode from the separated battery contents, and can recover each active material with high purity and high yield. The object is to provide a method for collecting goods.
[0004]
[Means for Solving the Problems]
The present inventors diligently studied to solve the above problems. First, various cutting methods etc. were examined about the decomposition | disassembly of the crimping part considered to be difficult in order to disassemble a dry cell. However, it has been extremely difficult to find a method that reduces the number of steps and can be used industrially.
By the way, in the secondary battery, in order to widen the electrode area and ensure a high battery capacity, the battery contents in which the positive electrode plate, the negative electrode plate and the separator are wound in a sheet shape are usually contained in the outer can. It has the structure accommodated in. The winding of each sheet-like plate in the battery contents is wound as tightly as possible in order to improve volumetric efficiency.
Then, the battery contents having a thickness larger than that of the outer can so as to pass through two predetermined points of the annular caulking portion and the outer can bottom of the secondary battery having such a structure and to cut the annular portion of the caulking portion . caulking of the cuts to have a shallower depth than the depth or the deep degree cutting the electrode plate or separator positioned in the outermost periphery in contact with the outer can inside surface, by providing more than more present, decomposition is thought to be difficult It has been found that the battery can be easily disassembled and the battery contents can be removed from the outer can easily and without crushing. In particular, by providing the cuts substantially evenly over a specific number, the wound structure which is the battery contents is expanded by the action of the reaction force against the winding, The present invention has been completed by finding that the caulked portion is disassembled by force and the battery contents and the outer can are separated from each other.
[0005]
That is, according to the present invention, the battery contents having a structure in which a positive electrode plate, a negative electrode plate, and a separator are wound, an outer can that contains the battery contents, and a lid that seals the outer can, The outer can is a method for recovering valuable materials from a waste secondary battery provided with an annular caulking portion for connecting and fixing the outer can and the lid portion,
It passes through the two predetermined points of the annular caulking portion and the outer can bottom, and is located on the outermost periphery in contact with the inner surface of the outer can of the battery contents so as to cut the annular portion of the caulking portion more than the thickness of the outer can. a step of forming two or more cuts which have a shallower depth than the depth or the deep degree to cut the plate or separator (a), the outer can was cut by step (a), the step of separating the battery content There is provided a method for recovering valuable materials from a waste secondary battery including (B) and a step (C) of separating the positive electrode and / or the negative electrode from the battery contents separated in the step (B).
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
The waste secondary battery to be implemented in the recovery method of the present invention includes a battery content having a structure in which a normal positive electrode plate, a negative electrode plate, and a separator are wound, an outer can that contains the battery content, and the outer sheath There is no particular limitation as long as the secondary battery has a lid portion that seals the can, and the exterior can has an annular caulking portion that connects and fixes the exterior can and the lid portion.
An example of such a secondary battery is a secondary battery having the structure shown in FIG. In FIG. 1, the secondary battery 10 includes an outer can 11 having a bottom portion 11b, a sealing plate 12 serving as a lid, a negative electrode plate 13d, separators (13a, 13c), and a positive electrode plate 13b. It is basically composed of 13. The outer can 11 is provided with an annular caulking portion 11a for connecting and fixing the outer can 11 and the sealing plate 12. Hereinafter, the recovery method of the present invention will be described with reference to FIG.
[0007]
In the recovery method of the present invention, first, the depth of the outer can is greater than the thickness of the outer can so as to pass through two predetermined points of the annular caulking portion 11a and the outer can bottom portion 11b and to cut the annular portion of the caulking portion 11a. Step (A) of providing two or more cuts to be performed is performed.
The cut line needs to be two or more, but facilitates the separation of the outer can 11 and the battery contents 13 in the next process, and the wound product (13a) of each plate constituting the battery contents 13 13b, 13c, and 13d) are opened by the cut, the reaction force against the winding acts on the side surface of the outer can, and the side surface of the cut outer can is spread and the side surface of the outer can spreads radially outward. At the same time, it is preferable that the number of cuts is large so that the caulking portion is automatically disassembled. The number is preferably 3 or more, and more preferably 6 to 10, and the side surface of the outer can is formed into a band shape by providing the cut. Moreover, it is preferable that the space | interval of each cut | interruption becomes substantially equal.
[0008]
The depth of the cut may be equal to or greater than the thickness of the outer can 11, but the battery contents 13 are separated from the outer can 11 while keeping the original shape as much as possible. It is preferable that the electrode plate or separator located on the outermost periphery in contact with the inner surface of the outer can 11 of the article 13, here the depth at which the separator 13 a is cut or a depth shallower than the depth.
Moreover, the direction of the cut line does not necessarily have to be a vertical direction, and may pass through two predetermined points of the annular caulking portion 11a and the outer can bottom portion 11b.
Examples of the means for providing the cut include means selected from the group consisting of a cutter, a saw, high-pressure water cutting, laser cutting, plasma cutting, gas cutting, and the like. For example, a cut can be provided using the jig 20 shown in FIG.
[0009]
In FIG. 2, the jig 20 has a cylindrical shape, and has an insertion port 21 for a waste secondary battery and an outlet 23 for taking out the inserted waste secondary battery. Cutters 22 for providing book breaks are provided at equal intervals. Further, the outlet 23 has eight recessed grooves for preventing the raised portion of the cut generated when at least the outer can of the waste secondary battery is cut by the cutter 22 from being caught by the outlet 23 and difficult to take out. 23a is provided.
The jig 20 can be used by a simple method in which the waste secondary battery is inserted from the insertion port 21 of the jig 20 and removed from the outlet 23 from the side where the caulking portion of the waste secondary battery is provided. At this time, when the jig 20 is fixed and used, the cut provided in the waste secondary battery is formed in the vertical direction. Further, a spiral cut is formed by passing the waste secondary battery while rotating the jig 20 or the waste secondary battery. Then, by using such a jig 20, the waste secondary battery taken out from the outlet 23 is taken out with the caulking portion disassembled, and the battery contents and the outer can are almost simultaneously with the removal. Since it is obtained in a separated state, the step (A) and the step (B) described later can be carried out continuously.
[0010]
In the recovery method of the present invention, next, the step (B) of separating the outer can 11 cut in the step (A) from the battery contents 13 is performed.
As in the example using the jig 20 described above, this step (B) can be performed continuously from the step (A), and when the caulking portion 11a is not automatically disassembled or the battery contents 13 are automatically Even if not separated from each other, the windings (13a, 13b, 13c, and 13d) of the plates constituting the battery contents 13 are opened by the cuts, and act to spread the side surface of the cut outer can. Therefore, the battery contents 13 can be easily separated from the outer can 11. At this time, if necessary, the battery contents 13 may be separated by spreading the outer can using tools such as pliers and clamps.
[0011]
Next, in the recovery method of the present invention, the step (C) of separating the positive electrode and / or the negative electrode from the battery contents 13 separated in the step (B) is performed.
The battery contents 13 separated from the outer can in the step (B) is separated from the positive electrode plate, the negative electrode plate, the separator, the lid, the gasket, the insulating plate, etc. in the form of the manufacturing process, so the positive electrode and / or the negative electrode Can be easily separated. Depending on the state of the waste secondary battery, the negative electrode active material may adhere to the separator or the outer can, but since it is not mixed with the positive electrode active material, there is no significant problem in separation. Further, when the electrode and the cover surface are connected by the lead portion, the lead portion can be separated at this point.
[0012]
In the recovery method of the present invention, it is sufficient that the steps (A) to (C) described above are included. Further, from the positive electrode and / or the negative electrode separated in the step (C), each of the positive electrode active materials by a known method, etc. In the case where the negative electrode active material is attached to the separator and the outer can, a step of recovering the negative electrode active material from the separator and the outer can can be performed. For example, it is preferable that the negative electrode active material is collected from the negative electrode, the separator, and the outer can and the positive electrode active material is separately collected from the positive electrode by water flow without crushing the electrode plate. At that time, it is effective to use a vibration sieve, an ultrasonic cleaner or the like. When the recovered active material contains a binder, a conductive material, and an unsorted active material, it is preferable to perform sieving and specific gravity separation. Since there is little if any active material that has not been separated, there is no significant reduction in the recovery rate due to this work. Alternatively, the separated and collected negative electrode and positive electrode are separately crushed and crushed and sieved to collect the active material. If necessary, impurities may be further removed by sieving and specific gravity separation as described above. . In addition, after performing steps (A) to (C), the active material can be dissolved in an acid, an alkali, or the like and recovered by a chemical precipitation method.
The recovery method of the present invention does not employ a conventional method of crushing the waste secondary battery together with the can, so that the active material of the positive electrode and / or the negative electrode can be recovered with high purity and high yield and reused. become. In addition, the outer cans, current collectors and the like separated by this method can be reused. Furthermore, the recovered active material can be used as the active material as it is or after being dissolved and made into a master alloy, re-dissolved, adding the necessary amount of elements, adjusting the composition, and It becomes.
[0013]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these.
Example 1
An AA size nickel-hydrogen battery was used as a waste secondary battery. The negative electrode of this battery is 8.7 g of a rare earth-nickel-based hydrogen storage alloy as an active material, punching metal as a current collector, the positive electrode is 6.3 g of nickel hydroxide as an active material, nickel foam as a current collector, and a separator. A polypropylene non-woven fabric, an outer can, and a cover surface made of steel are used.
The jig 20 shown in FIG. 2 described above was fixed, and the waste secondary battery was allowed to pass through as described above, thereby separating the waste secondary battery into an outer can, a sealing plate, and battery contents. Separation of the battery contents could be easily performed by gently opening the crimped portion of the cut outer can by hand. At this time, the lead portion connecting the positive electrode and the battery lid surface was cut.
Next, the positive electrode and the negative electrode were taken out by manually unwinding the positive electrode plate, the separator, and the negative electrode plate that were wound and laminated. The positive electrode was able to be taken out cleanly without the active material layer collapsing. Since the negative electrode active material was partially attached to the separator and the outer can, the attached negative electrode active material was also recovered by washing with water. The collected positive electrode and negative electrode were each washed with water to separate and collect into a current collector and an active material. The above operation was performed on a total of 100 waste secondary batteries.
As a result, an average of one battery, 8.2 g of hydrogen storage alloy, 6.0 g of nickel hydroxide, and 1.6 g of foamed nickel were recovered.
[0014]
Comparative Example 1
100 nickel-hydrogen batteries having the same AA size as in Example 1 were used, and crushed into lumps of 1 cm or less using a uniaxial crusher. This crushed material was sieved by a wet method. On the upper side of the sieve, nickel foam, which is a positive electrode current collector that does not break finely, and positive electrode active material attached to it, punching metal, which is a negative electrode current collector, separator debris and outer cans, and insulation Plastics were collected. What passed through the sieve screen was a negative electrode active material peeled off from the punching metal and a positive electrode active material peeled off from the foamed nickel. The recovered powder at this stage had a composition ratio of about 60% for the negative electrode active material and about 40% for the positive electrode active material. The recovered powder was sufficiently stirred in a container filled with water, and separated into a negative electrode active material and a positive electrode active material by specific gravity difference separation. The recovered powder contained about 95% of the negative electrode active material and about 5% of the positive electrode active material.
As a result, an average of one battery and about 6.5 g of hydrogen storage alloy (however, mixed powder with about 0.35 g of nickel hydroxide) were obtained. Moreover, nickel hydroxide, foamed nickel, and the outer can were not effectively separated as described above.
[0015]
【The invention's effect】
In the recovery method of the present invention, in particular, since the above-mentioned step (A) is adopted, the waste secondary battery is discarded by a substantially simple single cutting step without adopting a method of crushing the waste secondary battery together with the can body. The outer can of the secondary battery can be disassembled, and the outer can and the battery contents can be easily separated. In addition, since the separated battery contents are obtained in a state substantially similar to the state at the time of manufacture, the positive electrode and the negative electrode can be easily separated and recovered, and each active material is separated and recovered with high purity and high yield. can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view for explaining the structure of a waste secondary battery used in the present invention.
FIG. 2 is a schematic view for explaining a jig that can be used in the recovery method of the present invention.
[Explanation of symbols]
10: Waste secondary battery
11: Exterior can
11a: Caulking part
11b: Exterior can bottom
12: Sealing plate
13: Battery contents
13a, 13c: Separator
13b: Positive electrode plate
13d: Negative electrode plate
20: Jig
22: Cutter

Claims (4)

A battery content having a structure in which a positive electrode plate, a negative electrode plate, and a separator are wound, an outer can that contains the battery content, and a lid portion that seals the outer can. A method for recovering valuable materials from a waste secondary battery provided with an annular caulking portion for connecting and fixing a can and a lid,
It passes through the two predetermined points of the annular caulking portion and the outer can bottom, and is located on the outermost periphery in contact with the inner surface of the outer can of the battery contents so as to cut the annular portion of the caulking portion more than the thickness of the outer can. the step of providing two or more cuts which have a shallower depth than the depth or the deep degree cutting the electrode plate or separator and (a),
A step (B) of separating the outer can cut by the step (A) and the battery contents;
A method for recovering valuable materials from a waste secondary battery, comprising a step (C) of separating the positive electrode and / or the negative electrode from the battery contents separated in the step (B).   2. The recovery method according to claim 1, wherein, in step (A), the intervals between the cuts are substantially equal, and three or more cuts are provided. 3. The recovery method according to claim 1, wherein in the step (A), each cut is provided by means selected from the group consisting of a cutter, a saw, a high-pressure water cutting, a laser cutting, a plasma cutting and a gas cutting. . The recovery method according to any one of claims 1 to 3 , wherein the active material is separated from the positive electrode and the negative electrode obtained in the step (C) without crushing the electrode plate.

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