CN207038562U - Soft pack battery - Google Patents

Abstract

The utility model provides a kind of soft-package battery, and it includes battery core and pack case.Pack case has the main body for housing battery core and the side sealing positioned at main body side.Wherein, side sealing has：Base portion, extend from the side horizontal of main body；And revers turn part, it is connected with base portion, inflection and is laminated on base portion.According in soft-package battery of the present utility model, because base portion directly extends from the side horizontal of main body, avoid the junction of the side of base portion and main body damaged, improve the security reliability of soft-package battery.Meanwhile the revers turn part inflection of side sealing and be laminated on base portion, so as to reduce the width of side sealing, improve the energy density of soft-package battery.

Description

Soft pack battery

technical field

The utility model relates to the field of batteries, in particular to a soft pack battery.

Background technique

In recent years, as the mileage requirements of power vehicles have become higher and higher, automobiles have also put forward more and more stringent requirements for the volumetric energy density of lithium-ion batteries, and improving the volumetric energy density of batteries is nothing more than two aspects , One is to develop new materials with high gram capacity; the other is to improve the volume utilization of batteries. For the former, cathodes with high nickel content or anodes with high graphitization are usually used to increase the energy density; for the latter, it is to optimize the structural design of the battery.

In soft-pack batteries, it has become a trend in the design of lithium-ion batteries to minimize or compress unnecessary volume waste in design. Usually, soft packs need to be packaged during the production process, and in order to ensure the strength of the sealing edge, the The packaging width has certain requirements. How to compress this part of the space while ensuring the packaging strength of the battery has become a challenge for many battery manufacturers.

In the prior art, referring to FIG. 1 , the side sealing edge S is usually bent upright and fixed to the side of the main body M, so that unnecessary waste of space can be compressed. The packaging shell 2 of the soft pack battery is usually composed of two layers of packaging film 21 (usually aluminum-plastic film). The inner fused layers 212 of the membrane 21 are bonded together. However, during the vertical bending process of the side seal S, since the bent part is the joint between the side seal S and the main body M, it is easy to damage the inner fusion layer 212 of the side seal S at the joint (refer to The circled part in FIG. 1 ) increases the risk of contact between the metal layer 213 in the packaging film 21 and the electrolyte, resulting in an increase in the ion channels inside the cell, an increase in the corrosion probability of the cell, and a decrease in the reliability of the cell.

Utility model content

In view of the problems in the background technology, the purpose of this utility model is to provide a pouch battery, which can improve the safety and energy density of the pouch battery.

In order to achieve the above purpose, the utility model provides a soft pack battery, which includes a battery cell and a packaging case. The packaging case has a main body for accommodating the electric core and side sealing edges on the side of the main body. Wherein, the side edge sealing has: a base extending horizontally from the side of the main body; and a folded portion connected to the base, folded back and folded on the base.

The beneficial effects of the utility model are as follows:

In the pouch battery according to the present invention, since the base directly extends horizontally from the side of the main body, damage to the joint between the base and the side of the main body is avoided, and the safety and reliability of the pouch battery is improved. At the same time, the folded part of the side sealing edge is folded back and folded on the base, thereby reducing the width of the side sealing edge and increasing the energy density of the pouch battery.

Description of drawings

Fig. 1 is the schematic diagram of the pouch battery of prior art;

Fig. 2 is a perspective view of an embodiment of a pouch battery according to the present invention;

Fig. 3 is a sectional view taken along line A-A of Fig. 2;

4 to 6 are schematic diagrams of different embodiments of the pouch battery of the present invention;

7 to 9 are schematic diagrams of different packaging shells of the pouch battery of the present invention;

Fig. 10 is a perspective view of another embodiment of the pouch battery according to the present invention.

Wherein, the reference signs are explained as follows:

1 cell S1 base

11-pole lug S2 folded part

2 pack shell S21 first hem

21 Packaging Film S22 Second Fold

211 Outer protective layer S23 The third hem

212 Inner fusion layer C concave cavity

213 metal layer T top edge sealing

M main body B bottom edge banding

S side edge banding

Detailed ways

The pouch battery of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 2 to FIG. 10 , the pouch battery according to the present invention includes a battery cell 1 and a packaging case 2 . The package case 2 has a main body M for accommodating the battery cell 1 and a side sealing edge S located on a side of the main body M. As shown in FIG. Wherein, the side sealing S has: a base S1 extending horizontally from the side of the main body M; and a folded portion S2 connected to the base S1, folded back and folded on the base S1.

In the pouch battery according to the utility model, since the base S1 extends horizontally directly from the side of the main body M, damage to the connection between the base S1 and the side of the main body M is avoided, and the safety and reliability of the pouch battery are improved. At the same time, the folded portion S2 of the side seal S is folded back and folded onto the base S1, thereby reducing the width of the side seal S and increasing the energy density of the pouch battery.

For ultra-thin batteries, the upright and bent side seal S in the prior art exceeds the upper surface of the main body M, occupying more thickness space and reducing the energy density of the pouch battery; while the side seal S of the utility model It is arranged in horizontal stacks, occupies a small thickness space, and will not exceed the upper surface of the main body M.

In the pouch battery according to the present utility model, with reference to Fig. 2 to Fig. 9, the packaging case 2 includes two layers of packaging film 21, and the two layers of packaging film 21 enclose the main body M containing the battery cell 1 in the middle, and on the side of the main body M The square sealing connection forms the side sealing edge S.

In the pouch battery according to the present invention, the tab 11 of the battery cell 1 needs to protrude from the packaging case 2 for easy connection with the outside. Two layers of packaging film 21 are sealed and connected around the main body M to form a plurality of sealing edges, and the sealing edge T that the tab 11 of the power supply core 1 passes through is defined as the top sealing edge T, and the sealing edge on the side of the main body M is defined as the side sealing edge S. Taking the tab 11 as the center, the direction of the side of the tab 11 is the aforementioned "side", and the direction in which the tab 11 extends can be defined as "front and rear".

In an embodiment of the pouch battery according to the present invention, referring to FIG. 8 , the two-layer packaging film 21 is one packaging film, and the one packaging film is folded in half to form two connected packaging films 21 . At the same time, a cavity C is formed on one layer of packaging film 21 , and the other layer of packaging film 21 is flat.

The molding process of the pouch battery of this embodiment is described in detail below: first, a cavity C is formed on a packaging film by punching, and then the battery cell 1 is placed in the cavity C; then, the packaging film is folded in half , so that it forms two layers of packaging film 21 connected up and down, and the two layers of packaging film 21 are sealed and connected at the periphery, thereby sealing the battery cell in the cavity C, wherein, the connecting parts of the two layers of packaging film on both sides of the cavity C are The side seal S, the connecting part of the two layers of packaging film on the front side of the cavity C is the top seal T; finally, the side seal S is bent to form the base S1 and the folded part S2.

It can be seen that, during the forming process of the pouch battery, the base S1 of the side seal S is always in a horizontal state without any bending process, so the connection between the base S1 and the side of the main body M will not be damaged.

After the folded portion S2 is stacked on the base S1, the base S1 and the folded portion S2 are compacted by hot pressing to prevent the folded portion S2 from rebounding after being bent, and at the same time prevent the total thickness of the base S1 and the folded portion S2 from being greater than the thickness of the main body M .

Of course, the shape of the two-layer packaging film 21 can be set according to requirements. For example, referring to FIG. 9 , a concave cavity C can be formed on both packaging films 21 . Correspondingly, referring to FIG. 7 to FIG. 9 , the two-layer packaging film 21 can be two independent packaging films 21 or a packaging film 21 folded in half.

In another embodiment of the pouch battery according to the present utility model, referring to FIG. 8 and FIG. 10, the two-layer packaging film 21 can be a packaging film 21, and the packaging film 21 is folded in half to form two layers. The attached packaging film 21. At the same time, a cavity C is formed on one layer of packaging film 21 , and the other layer of packaging film 21 is flat. Wherein, the side folded in half is located on the side of the concave cavity C. That is to say, the two-layer packaging film forms a side seal S on one side of the cavity C, forms a top seal T on the front side of the cavity C, and forms a bottom seal B on the rear side of the cavity C.

In the pouch battery according to the present invention, referring to FIG. 7 to FIG. 9 , each packaging film 21 includes an outer protective layer 211 , an inner fusion layer 212 and a metal layer 213 between the outer protective layer 211 and the inner fusion layer 212 . Wherein, the outer protective layer 211 is preferably nylon, the inner fusion layer 212 is preferably polypropylene, and the metal layer 213 is preferably aluminum foil.

In an embodiment of the pouch battery according to the present invention, referring to FIG. 4 , the folded portion S2 only has a first folded edge S21 , which is connected to and attached to the base S1 .

In another embodiment of the pouch battery according to the present invention, the folded portion S2 is folded back into a plurality of stacked folded edges. Specifically, referring to FIG. 2 and FIG. 3 , the plurality of folded edges include: a first folded edge S21 connected to the base S1; and a second folded edge S22 connected to the first folded edge S21 and clamped on the first folded edge S21. Between side S21 and base S1. During the molding process of the pouch battery, the side sealing edge S needs to be trimmed, resulting in the exposed metal layer 213 on the end surface of the free end of the side sealing edge S, and the exposed metal layer 213 is likely to cause a short circuit. In this embodiment, however, the free end of the side seal S (that is, the free end of the second fold S22) is clamped between the first fold S21 and the base S1, so the metal layer 213 exposed on the end surface is covered by the first fold. The side S21 and the base S1 are coated, so as to insulate and seal the metal layer 213 .

In yet another embodiment of the pouch battery according to the present invention, the folded portion S2 is folded back into a plurality of stacked folded edges. Specifically, referring to FIG. 5 , the plurality of folded edges include: a first folded edge S21, connected to and attached to the base S1; and a second folded edge S22, connected to the first folded edge S21, and the first folded edge S22 The hem S21 is sandwiched between the second hem S22 and the base S1.

In yet another embodiment of the pouch battery according to the present invention, the folded portion S2 is folded back into a plurality of stacked folded edges. Specifically, referring to FIG. 6 , the plurality of folded edges include: a first folded edge S21 connected to the base S1; a second folded edge S22 connected to the first folded edge S21 and clamped between the first folded edge S21 and the base Between S1; and the third edge S23, connected to the second edge S22 and clamped between the first edge S21 and the second edge S22.

The folded portion S2 that is folded back into a plurality of stacked folded edges can effectively reduce the overall width of the side seal S and increase the energy density of the battery. During the forming process of the pouch battery, multiple folded edges are formed by bending the side seal S multiple times.

Claims (10)

1. A soft pack battery, comprising a battery cell (1) and a packaging case (2); The packaging case (2) has a main body (M) for accommodating the battery cell (1) and a side sealing edge (S) on the side of the main body (M); It is characterized in that, Side banding (S) has: a base (S1) extending horizontally from the sides of the main body (M); and The folded portion (S2) is connected to the base portion (S1), folded back and folded onto the base portion (S1). 2. The pouch battery according to claim 1, characterized in that, the folded part (S2) has only the first folded edge (S21), is connected with the base part (S1) and is attached to the base part (S1). 3. The pouch battery according to claim 1, characterized in that, the folded portion (S2) is folded back into a plurality of stacked folded edges. 4. The pouch battery according to claim 3, wherein the plurality of folded edges comprise: a first flap (S21), connected to the base (S1); and The second hem (S22) is connected to the first hem (S21) and clamped between the first hem (S21) and the base (S1). 5. The pouch battery according to claim 3, wherein the plurality of folded edges comprise: a first hem (S21), connected to and attached to the base (S1); and The second edge (S22) is connected to the first edge (S21), and the first edge (S21) is clamped between the second edge (S22) and the base (S1). 6. The pouch battery according to claim 3, wherein the plurality of folded edges comprise: The first folded edge (S21) is connected to the base portion (S1); a second flap (S22), connected to the first flap (S21) and sandwiched between the first flap (S21) and the base (S1); and The third edge (S23) is connected to the second edge (S22) and clamped between the first edge (S21) and the second edge (S22). 7. The soft pack battery according to claim 1, characterized in that, the packaging shell (2) comprises two layers of packaging film (21), and the two layers of packaging film (21) form a space for storing the battery cell (1) in the middle. The main body (M) is sealed and connected at the side of the main body (M) to form a side sealing edge (S). 8. The pouch battery according to claim 7, characterized in that, A cavity (C) is formed on one layer of packaging film (21), and the other layer of packaging film (21) is flat; or, Concave cavities (C) are formed on the two layers of packaging films (21). 9. The pouch battery according to claim 7, characterized in that, The two-layer packaging film (21) is two independent packaging films (21); or, The two-layer packaging film (21) is one packaging film, and the one packaging film is folded in half to form two connected packaging films (21). 10. The soft pack battery according to claim 7, characterized in that each packaging film (21) comprises an outer protective layer (211), an inner fusion layer (212) and an outer protective layer (211) and an inner fusion layer ( 212) between metal layers (213).