KR101875962B1 - Pouch type secondary battery cell with high-stiffness and Structure for assembling thereof - Google Patents

Abstract

The present invention relates to a high rigidity pouch and a secondary battery using the same. More particularly, the present invention relates to a high rigidity pouch which does not need a separate reinforcing material by using a high strength metal outer case made of a tap- For the secondary battery.
According to the present invention, it is possible to use a metallic material having rigidity by providing a groove for attaching the lead tab, and it is possible to overcome the external impact weakness which is a disadvantage of the existing pouch battery cell, .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-rigidity pouch type secondary battery cell and a cell assembly structure thereof.

The present invention relates to a high rigidity pouch type secondary battery cell and a cell assembly structure thereof, and more particularly, to a high rigidity pouch type secondary battery cell using a high strength metal material, And an assembly structure for assembling such secondary battery cells.

Lithium ion secondary batteries (including polymer batteries) are attracting attention as next-generation energy storage materials and are used in various applications such as electronic products, automobiles, and smart grids.

Lithium ion secondary batteries for automobiles have various forms according to OEM manufacturers, and they are classified into can type and pouch type. The shape of the lithium ion secondary battery was selected mainly by an OEM manufacturer, and was applied to a structure in which a module and a pack were formed in accordance with the determined cell shape. However, due to the importance of module / pack operation, it is necessary to select cell type centering on automobiles.

The can type and pouch type lithium ion secondary battery centered on OEM manufacturers currently used has room for improvement in order to be a high output, high capacity and light weight cell for automobile use.

1, in the case of a pouch type, the secondary battery 100 includes a metal layer 110, a sealing layer 113, a pouch outer layer 111, a lead tab metal layer 121, (120), and are manufactured by thermally fusing with the heat fusion dies (100-1, 100-2).

That is, a secondary battery (particularly, a polymer battery) is manufactured by forming a 120 to 200 μm film composed of an outer layer / a metal layer / an inner layer (a sealing layer) in a desired shape.

As shown in Fig. 1, the lead tabs to be electrically connected are attached by using a heat fusion mold having a certain shape so that the lead tab metal layer and the metal layer of the pouch do not come into contact with each other. At this time, the pouch deforming portion 130 is formed.

The material of the lead tab and the cross-sectional area affect the resistance of the battery cell and also affect the processing method in the direct / parallel connection.

As shown in FIG. 1, conventionally, a work is performed by using a hot-melt mold having a step, and a pouch is deformed at a step portion during the operation, and the thickness of the lead tab is usually about 0.1 to 0.4 t . Further, the thicker the thickness, the larger the amount of deformation.

Because of the thickness restriction of the lead tab, the welding process is applied when the battery cells are connected to each other, so that not only a failure occurs in the welding operation but also the reworking after the operation is impossible. The range of recycling is limited.

Also, in case of such a pouch type, the structure is hard, but the exterior material is soft and weak against external impact, so that the disadvantages are overcome by using a separate exterior material when manufacturing the module.

A diagram showing this is shown in Fig. Referring to FIG. 2, a module is fabricated by applying a technique to supplement the rigidity of the secondary battery cell using additional aluminum covers 210-1 and 210-2, a partition 220, and the like. At this time, a welding method is used as a method for connecting the secondary battery cells in series and / or in parallel.

In this process, the number of parts, the number of processes, and the number of modules increase, resulting in a cost incurred and a performance deterioration from a vehicle viewpoint.

In addition, there is a limitation in use of the lead tab thickness in order to secure the heat fusion property, and there are disadvantages in that various restrictions are imposed on assembling the module.

1. Korean Patent Publication No. 10-2010-0099063 2. Korean Patent Publication No. 10-2010-0030697 3. Korean Patent Publication No. 10-2009-0113430

The present invention has been proposed in order to solve the problems according to the related art, and it is an object of the present invention to provide a highly rigid pouch type secondary battery cell capable of lowering the cost and improving performance without increasing the number of parts / The purpose is to provide.

It is another object of the present invention to provide a highly rigid pouch-type secondary battery cell which improves the assembling performance of the module by mitigating the use limit on the lead tab thickness during heat fusion.

Another object of the present invention is to provide a cell assembling structure for assembling such highly rigid pouch type secondary battery cells in series and / or in parallel.

The present invention provides a highly rigid pouch-type secondary battery cell using a high strength metal outer sheath fabricated with a lead tab attaching portion without a separate reinforcing member, in order to achieve the above object.

Wherein the secondary battery cell comprises: an electrode jelly roll to which lead tabs are attached at both ends; An upper casing disposed at an upper end of the electrode jelly roll and having a lead tab mounting portion on which the lead tab is mounted; And a lower casing member which is fused to the upper casing by thermal fusion to be positioned at a lower end of the electrode jelly roll and in which a lead tab mounting portion to which the lead tab is mounted is selectively formed.

In this case, the lead tab attaching portion may be a planar groove formed on the frame surface of the case.

The lead tab attaching portion may be a protruding groove formed to protrude from the frame surface of the case.

The lead tab may be formed with a fastening hole for fastening a screw or a bolt.

Further, the upper casing or the lower casing may have fastening holes for screw or bolt fastening.

In addition, the upper casing or the lower casing may be provided with a correcting hole for precise positioning of the electrode jelly roll.

According to another aspect of the present invention, there is provided a rechargeable battery cell assembling structure, wherein the rechargeable battery cell assemblies are assembled in series or in parallel using the fastening means.

At this time, the fastening means may be a bolt type.

Further, the assembly may be characterized in that the assembly is performed in the lateral direction or the longitudinal direction.

Further, a case may be further added, and a cooling channel may be provided on the case side.

According to the present invention, it is possible to use a metallic material having rigidity by providing a groove for attaching the lead tab, and it is possible to overcome the external impact weakness which is a disadvantage of the existing pouch battery cell, .

In addition, as another effect of the present invention, it is possible to minimize external defects due to transportation and handling in manufacturing by implementing high stiffness compared to the pouch type, and to prevent defective manufacturing of module and pack system.

As another effect of the present invention, the thickness of the lead tab can be increased through the grooving of the casing for thermal fusion, so that it is possible to manufacture a module by screwing or the like without welding.

Further, as another effect of the present invention, such a screw fastening method is possible, so that it can be easily disassembled even when recycled.

1 is a view showing a state before and after thermal fusion of a secondary battery cell according to the prior art.
2 is an assembled perspective view showing a state in which a stiffener of a secondary battery cell according to a related art is further assembled.
3 is an assembled perspective view of a secondary battery cell according to an embodiment of the present invention.
FIG. 4 is an external perspective view of a secondary battery cell assembled according to FIG. 3. FIG.
5 is a perspective view of the lower casing 330 shown in FIG.
6 is a cross-sectional view of the secondary battery cell 400 shown in FIG.
7 is a first example for parallel assembly of secondary battery cells according to an embodiment of the present invention.
8 is a second example for serial assembly of secondary battery cells according to an embodiment of the present invention.
FIG. 9 is a third example for serial assembly of secondary battery cells according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a highly rigid pouch type secondary battery cell and its cell assembly structure according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is an assembled perspective view of a secondary battery cell according to an embodiment of the present invention. Referring to FIG. 3, the secondary battery cell includes an electrode jelly roll 320 to which lead tabs 321 are attached at both ends thereof; An upper casing 310 which is positioned at an upper end of the electrode jelly roll 320 and in which a lead tab attaching portion (510, 520 of FIG. 5) to which the lead tab 321 is mounted is selectively formed; And a lower casing member 330 positioned at a lower end of the electrode jelly roll 320 and having a lead tab attachment portion to which the lead tab is mounted.

A lead tab 321 is formed at both ends of the electrode jelly roll 320. Of course, the electrode jelly roll 320 includes a positive electrode plate (not shown), a negative electrode plate (not shown), and a separator (not shown).

The positive electrode plate (not shown), the negative electrode plate (not shown) and the separator (not shown) are each formed of a strip, and are arranged in the order of the positive electrode plate, the separator and the negative electrode plate.

The positive electrode plate (not shown) may be formed by mixing a binder and a conductive additive with powders for the positive electrode active material to form an active material layer in the form of a slurry and then uniformly coating the same on a conductive plate, . As the cathode active material, lithium metal oxides such as LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiCrO ₂ , or LiMn ₂ O ₄ may be used.

Since the electrode jelly roll 320 is well known in the art, further explanation will be omitted for the sake of clear understanding of the present invention.

FIG. 4 is an external perspective view of a secondary battery cell assembled according to FIG. 3. FIG. Referring to FIG. 4, the upper casing 310, the electrode jelly roll 320, and the lower casing 330 are fused by thermal fusion.

In addition, the electrode jelly roll 320 is injected into the sheathing 310, 330 of a thin metal material coated with a thermally adherable material capable of maintaining the rigidity, and then the electrode jelly roll 320 is injected with the electrolyte solution and thermally fused.

5 is a perspective view of the lower casing 330 shown in FIG. Referring to FIG. 5, lead tab attaching portions 510 and 520 are formed at the center of both ends of the lower casing member 330. The lead tab attaching portions 510 and 520 are the portions where the lead tabs 321 of FIG. 3 are mounted.

The first lead tab attaching portion 510 of the lead tab attaching portions 510 and 520 has a planar groove shape formed on the frame surface of the lower case member 330. A partial enlarged view showing this is shown on the lower left.

Alternatively, the second lead tab attaching portion 520 may have a protruding groove shape protruding from the frame surface of the casing. A partial enlarged view showing this is shown on the upper left side.

In addition, the lower casing member 330 is formed with a right-side assembling groove 530 at each inner edge so that the electrode jelly roll (320 of FIG. 3) is in a correct position. A partial enlarged view showing this is shown in the upper right corner.

Although only the lower casing member 330 is shown in FIG. 5, the upper casing member 310 is formed similarly to the system shown in FIG. Further, the lead tab attaching portions 510 and 520 and / or the right position attaching groove 530 are formed on both the upper casing member and the lower casing member 310 and 330.

Alternatively, as another example, the lead tapped mounting portion 520 and / or the right positioning mounting groove 530 may be formed. The lid tab attaching portions 510 and 520 and / or the right position attaching groove 530 may be formed only on the lower casing member 310. In addition, Of course, the opposite is also possible.

Here, the shape of the lead tab attaching portions 510 and 520 may vary depending on the shape of the lead tab. For example, if the lead tab is polygonal, the lead tab attaching portions 510 and 520 are also polygonal.

6 is a cross-sectional view of the secondary battery cell 400 shown in FIG. 6 is a cross-sectional view of the lead tab sealing portion of FIG. 4. FIG.

6, a lead tab 321 attached to both ends of the electrode jelly roll 320, a lead tab thermally fused portion 610 to which the lead tabs are fused by heat welding, and the electrode jelly roll 320, And the lower casing member 330 positioned at the lower end of the electrode jelly roll 320 are fused by heat welding.

Here, the lead tab 321 may be formed with a fastening hole (not shown) for a screw and / or bolt fastening method. A view showing the shape of this fastening hole is shown in Figs. 7 to 9. Fig. This will be described later.

Of course, such fastening holes may also be selectively machined on the top skin and / or the bottom skin.

According to one embodiment of the present invention, the lead tab 321 may be 0.4 t or more thick.

FIGS. 7 to 9 are views showing an example of assembling the secondary battery cells manufactured in accordance with FIG. 3 to FIG. 6 in parallel and / or in parallel.

7 is a first example for parallel assembly of secondary battery cells according to an embodiment of the present invention. Referring to FIG. 7, as an example of the two parallel battery cells ASS'Y, a module can be freely configured by using two parallel-connected battery cells.

In other words, two battery cells are assembled by using the first assembly frame 700. To this end, the assembling frame 700 and the hole-shaped fastening portions 701, 703 and 710 are formed on the battery cells. Also, in the case of a battery cell, the lead tab has a crook shape.

8 is a second example for serial assembly of secondary battery cells according to an embodiment of the present invention. Referring to FIG. 8, an example of a two-series battery cell ASS'Y is a structure in which the number of series is increased by continuous assembly.

Therefore, a module can be manufactured by only the assembly frame 900 without parts such as welding or a case, and a cooling channel is provided on the case side when a case is added, and a cooling channel can be secured only by adjusting the cell cell assembly interval.

In addition, the area of the sealing portion (dotted line) can serve as a cooling fin.

8, fastening portions 801, 803 and 810 are formed similarly to Fig. 8 and 7 illustrate a serial assembly method in which battery cells are assembled in the longitudinal direction.

FIG. 9 is a third example for serial assembly of secondary battery cells according to an embodiment of the present invention. Referring to Fig. 9, there is shown an example of four serial modules assembled in the lateral direction. 9, fastening portions 901 and 903 are formed.

100: secondary battery cell
100-1, 100-2: Heat fusion mold
110: metal layer 111: pouch outer layer
113: sealing layer 120: lead tab sealing layer
121: lead tab metal layer
130: pouch modification part 210-1, 210-2: additional aluminum cover
220: Partition
400: Secondary battery cell
310: upper casing material 320: electrode jelly roll
321: Lead tab
330: Lower casing
510, 520: lead tab mounting portion 530:
610: lead tab thermal fusing part
700,800,900: Assembly frame

Claims (8)

An electrode jelly roll to which lead tabs are attached at both ends;
An upper casing disposed at an upper end of the electrode jelly roll and having a lead tab mounting portion on which the lead tab is mounted; And
And a lower casing member which is fused to the upper casing member by thermal fusion to be positioned at a lower end of the electrode jellyroll and in which a lead tab mounting portion to which the lead tab is mounted is selectively formed,
Wherein the upper casing and the lower casing are made of a thin metal material coated with a thermally adherable material capable of maintaining rigidity, and the electrode jelly roll is inserted, and the electrolyte is injected after being injected into the high rigidity pouch type secondary battery cell .
The method according to claim 1,
Wherein the lead tab attaching portion is a planar groove formed on the frame surface of the casing.
The method according to claim 1,
Wherein the lead tab attaching portion is a projecting groove formed to protrude from the frame surface of the casing.
The method according to claim 1,
Wherein one of the lead tab, the upper casing and the lower casing is formed with a fastening hole for a screw or bolt fastening method.
The method according to claim 1,
Wherein the upper jacket material or the lower jacket material is provided with a positive positioning hole for positively assembling the electrode jelly roll.
A secondary battery cell assembly structure comprising a plurality of secondary battery cells according to any one of claims 1 to 5 assembled in series or in parallel using fastening means.
The method according to claim 6,
Wherein the fastening means is of a bolt type and the assembling is of a transverse or longitudinal direction. 8. The method of claim 7,
Wherein a case is further added, and a cooling channel is provided on a side surface of the case.

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