KR20050000725A - Pouch type battery pack - Google Patents

Abstract

PURPOSE: A pouch battery pack is provided, to reduce the percent defective of a pack by reducing the appearance damage of a battery when a pack is disassembled. CONSTITUTION: The pouch battery pack comprises a plurality of pouch batteries(a, b), wherein an adhesive tape(20) of a low adhesion is interposed between a pouch case main body(4a, 4b) of arbitrary pouch battery and a pouch case cover of another pouch battery to be combined with the pouch battery, to allow the plurality of pouch batteries to be combined one another so as to be detachable. Also the pouch battery pack comprises a pouch battery and a pack case, wherein an adhesive tape with low adhesion is interposed between the pouch battery and the pack case to allow the pouch battery to be combined with the pack case so as to be detachable. Preferably the adhesive power of the adhesive tape is 400 gf/25 mm or less.

Description

Pouch battery pack {Pouch type battery pack}

The present invention relates to a pouch battery pack, and more particularly, a pouch battery pack that can prevent damage to the pouch envelope during the decap operation of disassembling the pack by interposing a low-adhesive adhesive tape between a plurality of pouch batteries. The present invention relates to a pouch battery pack in which a pouch battery is attached to a pack case using a low-adhesive adhesive tape.

In general, secondary batteries are rechargeable and can be miniaturized and large-capacity. Typically, nickel-hydrogen (Ni-MH) batteries and lithium (Li) secondary batteries are used.

The secondary battery may be classified into a cylindrical battery using a cylindrical aluminum can, a square battery using a square aluminum can, and a pouch-type battery housed in a thin pouch case according to the appearance of a case housing the electrode plate assembly.

The general structure of the pouch type secondary battery includes an electrode assembly for generating a predetermined current, and a pouch case surrounding and sealing the electrode assembly. The electrode assembly is formed by stacking or winding a positive electrode plate and a negative electrode plate through a separator, and have electrode tabs such as a positive electrode tab and a negative electrode tab extending from the respective electrode plates. Each of the electrode tabs is provided such that a protective tape is adhered to the surface thereof to partially protrude out of the pouch case.

The pouch case includes a pouch case body provided with an inner space for mounting the electrode assembly, and a pouch case cover formed integrally extending from one end of the pouch case body. An edge of the pouch case body is formed to be joined to the pouch case cover and to seal the pouch case body.

On the other hand, such a pouch case is often used to insulate the surface of a metallic thin plate, such as aluminum thin plate, that is, a modified polypropylene, for example, a polymer resin, such as CPP (Casted Polypropylene) to form a thermal adhesive layer on the aluminum thin plate It is apply | coated and the resin material like nylon and polyethylene terephthalate (PET) is formed in the outer surface.

As described above, when the pouch case cover is joined to the flange of the pouch case main body to form a battery pack as a single pouch battery, one protection circuit is connected to one pouch battery with the pouch case upside down. That is, the flanges of the side portions of the joined flanges from which the positive electrode tabs and the negative electrode tabs are not drawn are folded toward the side of the pouch case body, and the derived positive electrode tabs and the negative electrode tabs are folded toward the bottom surface of the inverted pouch case. Protective circuits are connected to electrode tabs such as tabs and negative electrode tabs.

In general, not only a single pouch battery as described above, but also a plurality of pouch batteries, protective circuits and other materials in the form of assembled in the frame can be mounted on a mobile phone or a notebook device. The protection circuit is not mounted for each pouch battery, but one protection circuit is mounted for a plurality of combined batteries to form one battery pack. In this case, the pouch batteries having substantially the same structure and shape are adhered to each other in close contact with each other. At this time, adhesive tapes generally sold on the market were used as a method of bonding between pouch batteries. In addition, in order to manufacture a pouch battery pack, the battery pack was formed using the conventional adhesive tape as mentioned above even when the pouch battery was attached to the pack case.

However, as a result of inspection of the defective work of the hard pack or core pack, when the internal material is not defective, it is necessary to disassemble the pack, take out the internal material, and repack the work. In this case, the conventional general adhesive tape adhered to the battery body Due to the increase in the pouch sheath or damage to the pouch sheath, the battery can not be used again.

The present invention is to solve the above problems, by using a plurality of pouch cells to form a core pack or a hard pack to form a battery pack using a low-adhesive tape to adhere the battery, or using a low-adhesive tape It is an object of the present invention to provide a pouch battery pack that manufactures a pack by attaching a pouch battery to a pack case, and thus reduces the appearance damage of the battery by deteriorating the appearance of the pack during decap work.

1 is a perspective view illustrating an assembly process of a battery pack of the present invention;

2 is a perspective view of an assembled battery pack according to the present invention;

3 is a schematic block diagram of a core pack of a battery pack of the present invention;

4 is a partial cutaway enlarged cross-sectional view of an adhesive portion;

5 is an assembled perspective view of a modification according to the present invention.

<Brief description of symbols for the main parts of the drawings>

a: first pouch battery b: second pouch battery

2a, 2b, 6a, 6b: flange 4a, 4b: pouch case body

8a, 8b: electrode tab 10a, 10b: sealing part

14a, 14b: pouch case cover 20: adhesive tape

22, 26: adhesive layer 24: adhesive base material

In order to achieve the above object, the pouch battery pack according to the present invention includes a plurality of pouch batteries, a low-adhesive adhesive tape is provided between the pouch case body of any pouch battery and the cover of another pouch battery to be bonded thereto. It is characterized in that the plurality of pouch battery is interposed detachably coupled to each other.

As another feature of the present invention, the pouch battery pack of the present invention includes a pouch battery and a pack case, interposed a low-adhesive adhesive tape between the pouch battery and the pack case, the pouch battery and the pack case is removable from each other. It is characterized by being coupled to.

Optionally, the adhesive force of the adhesive tape is preferably 400 gf / 25 mm or less.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 illustrates a process of assembling a plurality of pouch batteries with an adhesive tape. Since the first pouch battery (a) and the second pouch battery (b) have substantially the same shape and structure, the configuration of each battery will be described based on the first pouch battery which is one of them.

In the structure of a general pouch battery, although not shown in the drawing, the battery assembly is mounted and covered with a pouch case cover 14a inside the pouch case body 4a, and the pair of electrode tabs 8a is sealed. 10a protrudes outward. In FIG. 1, such a pouch battery is shown in an inverted shape. On both sides of the pouch case body 4a, flanges 2a and 6a are formed in the longitudinal direction.

Between the first pouch battery (a) having the above-described structure and the second pouch battery (b) having a substantially same shape, an adhesive tape 20 having adhesiveness on both sides is interposed, so that the first pouch battery and the second The pouch battery is bonded by an adhesive tape. The shape of the adhesive tape is not limited to the quadrangle as shown in FIG. 1 and may have various shapes such as a circle as necessary. However, since the adhesive tape 20 is adhered to the pouch case cover 14a of the first pouch battery a and the pouch case body 4b of the second pouch battery b, the size of the adhesive tape 20 is It is smaller than or equal to the size of the pouch case cover 14a and the pouch case body 4b, and the adhesive tape does not protrude out of the battery.

The pouch case body 4b of the second pouch battery b, which is in contact with the pouch case cover 14a of the first pouch battery a with the adhesive tape 20 therebetween, has both flanges ( 2b, 6b) protrude to a position higher than or at least the same height, so that when the adhesive tape 20 is interposed, both sides of the adhesive tape 20 are separated from the pouch case cover 14a of the first pouch battery and the second pouch battery. It comes in contact with the pouch case body 4b.

FIG. 2 shows a perspective view of a state in which the first pouch battery a and the second pouch battery b are bonded to each other and a protective circuit is further mounted. Two electrode tabs 8a of the first pouch cell a and two electrode tabs 8b of the second pouch cell are connected to the protection circuit 30, and the protection circuit 30 is one of a plurality of adjacent pouch cells. It is mounted on top of either seal, preferably on top of the seal of the pouch battery with the seal exposed to the outside.

3 is a block diagram showing a schematic configuration of a core pack of the battery pack according to the present invention. 3 illustrates a core pack state using two pouch cells as an example. However, the present invention is not limited to using two pouch displacers, and three or more pouch cells may be used as necessary. Between the first pouch cell (a) and the second pouch cell (b) having substantially the same structure and shape are interposed double-sided adhesive tape 20 for adhering the two pouch cells are bonded to each other. In addition, each of the electrode tabs 8a and 8b of the first pouch battery and the second pouch battery may be electrically connected to the protection circuit 30 to form a core pack. The pack work put together in a frame makes a complete battery pack.

The plurality of pouch cells bonded as described above may be separated by a force exceeding the adhesive force of the adhesive tape when the decap work is required.

4 is an enlarged cross-sectional view partially showing a portion where an adhesive tape, a first pouch battery, and a second pouch battery are bonded to each other; The adhesive tape 20 has a structure in which adhesive layers 22 and 26 having constant adhesive strength are applied to both surfaces of the adhesive base material 24. Accordingly, the adhesive layer 22 applied to one side of the adhesive base material 24 is attached to the pouch case cover 14a of the first pouch battery, and the adhesive layer 26 applied to the other side of the adhesive base material 24. ) Is attached to the pouch case body 4b of the second pouch battery so that the first pouch battery and the second pouch battery are integrated through the adhesive tape 20.

FIG. 5 shows an embodiment modified from the embodiment shown in FIGS. 1 to 4. In more detail, FIG. 5 illustrates a process in which the pouch battery and the pack case are combined and assembled. 1 to 4 illustrate the case where the pouch batteries are coupled to each other, but FIG. 5 illustrates a structure in which the pouch battery is adhered to the pack case using an adhesive tape. The pack case 34 to which the pouch case cover 14a 'of the pouch battery a' is to be provided has a mounting portion 32 having a complementary shape to accommodate the pouch case cover. A low-adhesive adhesive tape is interposed between the pouch battery a 'and the pack case 34 so that the pouch battery is detachably bonded to the pack case. In more detail, a low-adhesive adhesive tape having an adhesive layer on both sides is interposed between the pouch case cover 14a 'of the pouch battery a' and the mounting portion of the pack case in which the pouch battery is accommodated and seated. The pouch cell and the pack case are adhered to both sides of the adhesive tape, and as a result, the pouch cell and the pack case are combined. If decap work is required after the gluing operation, the pouch battery and the pack case can be separated by applying a force exceeding the adhesive strength of the adhesive tape.

Although FIG. 5 illustrates a single pouch battery adhered to a pack case, a plurality of combined pouch cells may be adhered to the pack case in the same manner. That is, the adhesive tape may be interposed between the pouch battery and the battery, and the adhesive tape may be interposed between the pouch battery and the pack case.

On the other hand, the adhesive force is a numerical value of the force that the tape or the binder is attached to other objects, and the standardized method of measuring the adhesive force of tapes is based on the method of KSP36978, the Korean standard. Adhesion is measured by measuring the peeling force of a tape or the like on the SUS plate. In general, adhesion is expressed in units of gf / mm.

In general, the adhesive force of the conventional adhesive tape used to bond the battery is more than 550gf / 25mm. If the adhesive strength of the adhesive tape is high, the adhesion performance of the battery will be excellent, but the pouch is often damaged during the decap operation of disassembling the pack. In addition, if the adhesive strength is too low, the reliability of the adhesive, which is the original purpose of the adhesive tape, becomes poor. Therefore, it is desirable that the adhesive force of the adhesive tape be maintained at an appropriate level so as to have a reliable adhesive strength without damaging the pouch during the decap operation.

In the case of adhering a plurality of pouch batteries, the experiment results for damage to the pouch case body or the pouch case cover according to the adhesive force of the adhesive tape interposed between the pouch case body and the pouch case cover of polyethylene terephthalate (PET) In the case where the adhesive force of the adhesive tape was 550 gf / 25 mm or more, the rate at which the appearance of the pouch was damaged during decapping exceeded an average of 50%. On the other hand, when the adhesive strength of the adhesive tape was 500gf / 25mm for the pouches of the same material and shape, the pouch appearance damage rate was 45% on average during the decap work. Also, when the adhesive force of the adhesive tape was 400gf / 25mm for the pouches of the same material and shape, the pouch appearance damage rate was 10% on average during the decap operation, and in this case, the adhesive strength between the cells was maintained at a reliable level. Furthermore, in the case of the adhesive tape having an adhesive force of 300 gf / 25 mm or less, the damage rate of the appearance was significantly decreased, but correspondingly, the adhesive strength between the batteries was also significantly reduced.

Even when the decap work was carried out by interposing the adhesive tape between the pouch battery and the pack case, the same results as in the adhesion test between the pouch batteries were also obtained.

In summary, when the adhesive force of the adhesive tape is less than 400gf / 25mm it can be seen that the damage rate of the pouch shell is significantly lowered to show the desirable performance.

After adhering the pouch battery using the adhesive tape having the above adhesive strength, if a defective product is found in the manufacturing process of the battery pack, but the defect is not in the internal material such as the battery or the protection circuit, the battery is bonded with the adhesive tape. Separate the available internal materials by decapturing the batteries from each other or by removing the batteries from the case. In this case, the pouch battery adhered by the adhesive tape having the adhesive force of 400 gf / 25 mm or less, the pouch battery is separated without damaging the outer skin of the pouch, the pouch battery maintains the good condition, the separated pouch battery is reused separately Can be.

According to the present invention as described above, the following effects can be obtained.

First, the phenomenon in which the pouch is increased during decap work is significantly prevented, and the appearance defect rate is lowered. Specifically, the pouch battery pack according to the present invention has an appearance defect rate lowered from 50% to 10% or less.

Second, since the appearance of the pouch does not increase during the decap operation, it is easy to put the pouch battery in the pack because the space between the packs does not become thick and maintains an appropriate thickness when the pack is configured with the pouch battery.

Third, it is possible to prevent the pouch from being damaged by preventing the pouch from being damaged.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (4)

In the pouch battery pack comprising a plurality of pouch batteries, A pouch battery pack, characterized in that the pouch battery is interposed between the pouch case body of any pouch battery and the pouch case cover of another pouch battery to be coupled thereto so that the plurality of pouch cells are detachably coupled to each other. The method of claim 1, The adhesive force of the adhesive tape is a pouch battery pack, characterized in that less than 400gf / 25mm. In the pouch battery pack including a pouch battery and a pack case, A low-adhesive adhesive tape is interposed between the pouch battery and the pack case, so that the pouch battery is detachably coupled to the pack case. The method of claim 3, wherein The adhesive force of the adhesive tape is a pouch battery pack, characterized in that less than 400gf / 25mm.