KR100472514B1 - Jelly-roll type electrode-assembly and method for making it - Google Patents

Abstract

An object of the present invention is to provide a jelly roll type electrode assembly having improved performance in terms of output, capacity, and the like, and a method of manufacturing the same, without requiring additional time and cost in manufacturing.

In order to achieve the above object, the present invention is:

Two or more pairs of insulating separators wound in direct contact with each end thereof;

Positive electrode plates and negative electrode plates alternately interposed between the separators;

Positive electrode tabs individually connected to each of the positive electrode plates; And

It provides a jelly roll-type electrode assembly having a; negative electrode tabs respectively connected to each of the negative electrode plate.

Description

Jelly-roll type electrode-assembly and method for making it

The present invention relates to a jellyroll type electrode assembly, and more particularly, to a jellyroll type electrode assembly having improved electrical properties.

As the demand for higher output power of batteries increases, it is necessary to form thinner thicknesses of the positive and negative electrode plates. However, simply reducing the thickness of the positive electrode plate and the negative electrode plate reduces the capacity of the battery, so that the length of the positive electrode plate and the negative electrode plate needs to be increased in order to achieve high output of the battery while maintaining or increasing the capacity of the battery. As a method of lengthening the length of the positive electrode plate and the negative electrode plate, there is a method of forming a single positive electrode plate and a negative electrode plate in a long way and employing two or more positive electrode plates and a negative electrode plate, respectively.

FIG. 1 shows a jelly roll electrode assembly in which one positive electrode plate 11, one negative electrode plate 12, and a separator 13 insulating the same are wound together, similar to those disclosed in Japanese Patent Laid-Open No. 2000-138052. 2, the state before winding the electrode assembly is shown.

However, in the case of the electrode assembly in which the length of the single positive plate and the negative electrode plate is longer than before, the positive electrode tab and the negative electrode tab are connected to only the ends of the positive electrode plate and the negative electrode plate. For example, unlike the case where there is no problem in current collection performance, it is necessary to have a non-coated portion (a portion where the current collector is not applied) in the middle of the positive electrode plate and the negative electrode plate and connect the positive electrode tab and the negative electrode tab to each other. This has the disadvantage of incurring additional time and cost due to the complexity of the manufacturing process.

Japanese Patent Laid-Open No. 2000-90977 discloses an electrode assembly having two pairs of positive and negative plates. However, this electrode assembly has a disadvantage in that the structure and shape of the electrode assembly to be manufactured is limited in that it has a structure that necessarily requires a positive electrode at the center thereof.

Disclosure of Invention It is an object of the present invention to solve the above problems, and to provide a jelly roll type electrode assembly having improved performance in terms of output, capacity, and the like, without requiring additional time and cost in manufacturing.

In order to achieve the above object, the present invention is:

Two or more pairs of insulating separators wound in direct contact with each end thereof;

Positive electrode plates and negative electrode plates alternately interposed between the separators;

Positive electrode tabs individually connected to each of the positive electrode plates; And

It provides a jelly roll-type electrode assembly having a; negative electrode tabs respectively connected to each of the negative electrode plate.

Preferably, the positive electrode tab is connected to one end of the positive electrode plate, and the negative electrode tab is connected to one end of the negative electrode plate.

The positive electrode tabs are disposed to face each other, the negative electrode tabs are disposed to face each other, and the positive electrode tabs and the negative electrode tabs are preferably spaced apart from each other.

The jelly roll type electrode assembly may further include a core on which one end of the separator is wound.

In addition, in order to achieve the above object, the present invention is:

Preparing at least two pairs of insulating separators, positive plates connected to positive electrode tabs, and negative plates connected to negative electrode tabs, respectively;

A first winding step of winding one end of each of the two or more pairs of insulating separators on the winding shaft;

An electrode plate interposing step of alternately interposing a positive electrode plate and a negative electrode plate between the separators; And

And a second winding step of winding the separators, the positive electrode plates, and the negative electrode plates together.

After the second winding step may further comprise a winding shaft removal step of removing the winding shaft.

After the winding shaft removal step, it is preferable to further include a space removing step of removing the space occupied by the winding shaft.

After the second winding step, it is preferable to further include an electrode tab fixing step of fixing the positive electrode tabs to each other and the negative electrode tabs to each other.

The preparation step preferably includes an electrode tab connecting step of connecting each positive electrode tab to one end of each positive electrode plate and connecting each negative electrode tab to one end of each negative electrode plate.

The electrode plate interposing step includes disposing the positive electrode plates such that the positive electrode tabs face each other and disposing the negative electrode plates so that the negative electrode tabs face each other, but disposing the positive electrode plates and the negative electrode plates so that the positive electrode tabs and the negative electrode tabs are spaced apart from each other. It is preferable.

Next, an embodiment of a jellyroll type electrode assembly according to the present invention will be described in detail with reference to the accompanying drawings.

3 illustrates a jellyroll electrode assembly according to the present invention, and FIG. 4 illustrates a state before winding the electrode assembly.

The jelly roll type electrode assembly includes separators 23, positive electrode plates 21, negative electrode plates 22, positive electrode tabs 21a, and negative electrode tabs 22a.

At least two pairs of the separators 23 are wound together in a state where each end thereof is in direct contact. However, the portions in which the separators are in direct contact with each other are only one end portion, and the positive electrode plate 21 or the negative electrode plate 22 is interposed from a portion spaced apart from each other by a predetermined distance in the longitudinal direction. The separators 23 have an insulating function to prevent the positive electrode plate and the negative electrode plate from directly contacting each other.

The positive electrode plate 21 and the negative electrode plate 22 are alternately interposed between the separators 23. That is, one cathode plate 21 is disposed on one side of one separator 23 and one cathode plate 22 is disposed on the other side. In the accompanying drawings, the positive electrode plate is shown to be wound on the outside of the negative electrode plate, but the negative electrode plate may be wound on the outside.

The positive electrode tabs 21a are individually connected to each of the positive electrode plates, and the negative electrode tabs 22a are individually connected to each of the negative electrode plates. The positive electrode tab and the negative electrode tab are energized with each of the positive electrode plate and the negative electrode plate. The positive electrode tab 21a and the negative electrode tab 22a are connected to only one end of each of the positive electrode plate 21 and the negative electrode plate 22. Of course, even if the positive electrode tab and the negative electrode tab is connected to the center portion of each of the positive electrode plate and the negative electrode plate, there is no problem in the performance of the battery, but it is preferable in terms of time and cost required for manufacturing the connection to the end.

Since the positive electrode tab 21a and the negative electrode tab 22a are not to be energized with each other, the positive electrode tab 21a and the negative electrode tab 22a are preferably spaced apart from each other. In order to prevent a short circuit caused by the positive electrode tab and the negative electrode tab, the positive electrode tab 21a and the negative electrode tab 22a are disposed at the center side of the electrode assembly. It is preferable to connect to the facing side. Meanwhile, in the jelly roll type electrode assembly according to the present invention, two or more positive electrode tabs and negative electrode tabs respectively exist, and the positive electrode tabs are eventually connected to the positive electrode of the electrode assembly accommodating means in which the electrode assembly is accommodated, and the negative electrode tabs eventually have electrodes. It is connected to the cathode of the assembly receiving means. Therefore, the positive electrode tabs and the negative electrode tabs may be connected to each other, and if necessary, it is preferable to be connected by a method such as welding for convenience in manufacturing. Therefore, the positive electrode tabs are preferably disposed to face each other, and likewise the negative electrode tabs are preferably disposed to face each other.

The electrode assembly shown in FIG. 3 is a rectangular electrode assembly, and after winding of the positive electrode plates, the negative electrode plates, and the separators, the winding shaft for winding is removed, and thus has a flat shape. In addition, the positive electrode plates, the negative electrode plates, and the separators have a thickness thinner than those of the conventional positive electrode plates, the negative electrode plates, and the separators shown in FIG. 2, as shown in FIG. 4, and the number thereof is two or more.

In order for the battery capacity of the electrode assembly according to the present invention to be equal to or larger than that of the conventional electrode assembly, the total length should be increased as the thickness of the positive electrode plate and the negative electrode plate decreases. For example, if the thickness is 1/2, the total length of the positive and negative plates should be doubled. Therefore, if each of the positive electrode plate and the negative electrode plate of the electrode assembly according to the present invention has a length of the conventional positive electrode plate and the negative electrode plate, two sheets of positive electrode plate and negative electrode plate are required. Assuming that the length of each of the positive electrode plate and the negative electrode plate is the same as the conventional positive electrode plate and the negative electrode plate, and calculated in the same manner as described above, when the thickness is 1/3, each of the three positive plate and negative plate and six separators are required. Hereinafter, the case where the thickness of the positive electrode plate and the negative electrode plate is 1/2 will be described.

Hereinafter, a first embodiment of a method for manufacturing a jelly roll type electrode assembly according to the present invention will be described with reference to FIG. 5.

The method for manufacturing a jelly roll type electrode assembly according to the first embodiment includes a preparation step, a first winding step, an electrode plate interposing step, a second winding step, a winding shaft removing step, a space removing step, and an electrode tab fixing step.

The preparation step is a step of preparing two or more pairs of insulating separators 23, positive plate 21 to which the positive electrode tab 21a is connected, and negative plate 22 to which the negative electrode tab 22a is connected, respectively. This step includes the steps of fabricating a positive electrode plate and a negative electrode plate formed of a predetermined material and having predetermined dimensions, and connecting the electrode tabs with the positive electrode tab and the negative electrode tab, respectively. In the electrode tab connection step, as described above, it is preferable to connect the positive electrode tab and the negative electrode tab with one end of the surface facing the center of the electrode assembly of the positive electrode plate and the negative electrode plate, respectively.

The materials of the positive electrode plate and the negative electrode plate are metals having different ionization tendencies, and specifically vary according to the type of battery. The separator is formed of an insulating material, it is preferable that the separator is manufactured in a somewhat larger size than the positive electrode plate and the negative electrode plate in order to prevent shorting at the peripheral portions of the positive electrode plate and the negative electrode plate. The positive electrode tab and the negative electrode tab are formed of a conductive material, and are typically electrically connected to the positive electrode plate and the negative electrode plate by welding.

The first winding step is a step of winding one end of each of the two or more pairs of insulating separators 23 on the winding shaft. In this step, the winding shaft is rotated or the separators are rotated around the winding shaft, which is usually rotated about two to three times, but may be rotated in fewer times to save the separator. Figure 5 shows the state after the first winding step in the first embodiment of the manufacturing method of the jelly roll-type electrode assembly according to the present invention, as shown in the first embodiment the mandrel (mandrel, 24a) It is set as a winding shaft, and a pair of separators are each taken out from both sides of this winding shaft, and the edge part is wound up to the said winding shaft.

The electrode plate interposing step alternately interposes the positive electrode plates 21 and the negative electrode plates 22 between the separators 23. As shown in FIG. 5, the anode plate 21 is disposed between the two separators on both sides, and the cathode plate 21 is disposed outside the separators on the uppermost and lowermost sides. The positive electrode plate and the negative electrode plate disposed as described above are disposed in the form interposed between the separators when the positive electrode plate and the negative electrode plate are wound by the second winding step described later.

The position of the electrode tab 21a, 22a of the completed jelly roll type electrode assembly is not only connected to which position of the electrode plate 21, 22, but also by how the electrode tabs are arranged before the second winding step described later. It is decided. Preferably, when the jelly roll type electrode assembly is completed, the positive electrode tab 21a and the negative electrode tab 22a are disposed to be spaced apart from each other, and the positive electrode tabs and the negative electrode tabs are preferably disposed to face each other. There are various arrangements of the positive electrode tab and the negative electrode tab satisfying such a condition. For example, as illustrated in FIG. 3, both the positive electrode tab and the negative electrode tab may be disposed on the upper side of the electrode assembly, but may be spaced apart in the horizontal direction. These may be disposed to face each other, but may be spaced apart in the longitudinal direction (in this case, as described below, the core 24b is disposed at the center of the electrode assembly and the positive and negative tabs are disposed on both sides of the core. For example, the negative electrode tab may be disposed at the center of the electrode assembly, and the positive electrode tab may be disposed at the periphery of the electrode assembly. In addition, one of the positive electrode tab and the negative electrode tab may be disposed above the electrode assembly and the other may be disposed downward. It is possible. FIG. 5 shows a state in which the electrode plate intervening step is completed, and it can be seen that the positive electrode tabs and the negative electrode tabs are disposed at the same position in the longitudinal direction, respectively, to satisfy the above condition.

The second winding step is a step of winding together the separators 23, the positive electrode plates 21, and the negative electrode plates 22 arranged as described above. This step is also performed by rotating the winding shaft, or by rotating the separators 23, the positive electrode plates 21, and the negative electrode plates 22 around the winding axis.

The winding shaft removal step is to remove the mandrel 24a, which is an unnecessary winding shaft in the completed electrode assembly. The mandrel must have a width greater than that of the positive electrode plate, negative electrode plate, and separator to be supported by another member, if the size of the battery is not an important factor or after the second winding step of the positive electrode plate, negative electrode plate, and separators. If cut to have the same width as the one with the largest width it does not have to be removed. Of course, since the volume occupied by Mandrel is an element that increases the size of the entire battery, it is preferable to be removed, but in the process of removing it, the arrangement of the positive electrode plate, the negative electrode plate, and the separator may be disturbed. If the thickness of is thin, it does not have to be removed. Therefore, this step is not necessary step in the present invention.

The space removing step is a step required when the mandel is removed by the winding shaft removing step, and removes the space occupied by the mandel by compression.

The electrode tab fixing step may be performed independently of the winding shaft removing step after the second winding step, and is to fix the positive electrode tabs between the positive electrode tabs and the negative electrode tabs by welding with each other. . Thus, fixing the same electrode tabs to each other is preferable for the subsequent battery assembly process.

In Fig. 5, in order to clearly show the wound state of the separator and the electrode plate, they are shown to have a somewhat exaggerated thickness, but the separator or the like is welded to the positive electrode tab and the negative electrode tab without being excessively bent with respect to each other. It is thin enough to be fixed.

Hereinafter, a second embodiment of a method for manufacturing a jelly roll type electrode assembly according to the present invention will be described with reference to FIG. 6 based on other matters than the first embodiment.

The second embodiment differs from the first embodiment in that two pairs of separators are pulled out from one side of the winding shaft, and the end thereof is wound around the winding shaft. As a result, both the positive electrode tabs 21a and the negative electrode tabs 22a are biased toward one side of the electrode assembly. Compared to the first embodiment, this embodiment has the advantage of saving the work space required to perform the first winding step and the second winding step.

FIG. 7 illustrates an electrode plate interposition step in a method of manufacturing a cylindrical jelly roll type electrode assembly having a core 24b in the middle of the electrode assembly. The cylindrical jelly roll electrode assembly is different from the rectangular jelly roll electrode assembly in that a core 24b is disposed at the center thereof, and the first winding step and the second winding step are performed based on the second winding step. Does not remove the core even after is terminated. Since the cylindrical jelly roll-type electrode assembly preferably has a perfect cylindrical shape possible after the second winding step is finished, the core has a cylindrical shape basically considering the volume increased by the positive electrode tab and the negative electrode tab. It is desirable to cut properly. In the electrode assembly, it is preferable that the positive electrode tabs 21a and the negative electrode tabs 22a are disposed to face each other with the core in the middle. In addition, in order for the positive electrode tabs and the negative electrode tabs to face each other, the length w of FIG. 7 (the circumferential length of the jelly roll when the tab is interposed between the separators) is about x (n + 1/2) long. It is preferable to set it as. N is a number selected from 0 and a natural number.

Although the present invention has been described with reference to the embodiments shown in the 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. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, a jelly roll type electrode assembly having improved performance in terms of output, capacity, and the like without requiring additional time and cost in manufacturing is provided.

1 is a perspective view showing a conventional jelly roll type electrode assembly,

FIG. 2 is an exploded perspective view illustrating the jellyroll type electrode assembly shown in FIG. 1;

3 is a perspective view illustrating a jellyroll electrode assembly according to the present invention;

4 is an exploded perspective view illustrating the jellyroll type electrode assembly shown in FIG. 3;

5 is a plan view showing an electrode plate interposition step of the first embodiment of the method for manufacturing a jelly roll type electrode assembly according to the present invention;

6 is a plan view illustrating an electrode plate interposition step in a second embodiment of a method for manufacturing a jellyroll type electrode assembly according to the present invention;

7 is a plan view showing an electrode plate interposition step of the method for producing a cylindrical jelly roll type electrode assembly.

Explanation of symbols on the main parts of the drawings

10, 20: jelly roll type electrode assembly 11, 21: the positive electrode plate

11a and 21a: positive electrode tabs 12 and 22: negative electrode plate

12a and 22a: negative electrode tabs 13 and 23: separators

24a: Mandrerel 24b: core

Claims (10)

Two or more pairs of insulating separators wound in direct contact with each end thereof; Positive electrode plates and negative electrode plates alternately interposed between the separators; Positive electrode tabs individually connected to each of the positive electrode plates; And And negative electrode tabs individually connected to each of the negative electrode plates. And the positive electrode tabs are disposed to face each other, the negative electrode tabs are disposed to face each other, and the positive electrode tabs and the negative electrode tabs are spaced apart from each other. The method of claim 1, The positive electrode tab is connected to one end of the positive electrode plate, the negative electrode tab is a jelly roll type electrode assembly, characterized in that connected to one end of the negative electrode plate. delete The method according to claim 1 or 2, A jelly roll-type electrode assembly further comprises a core on which one end of the separator is wound. Preparing at least two pairs of insulating separators, positive plates connected to positive electrode tabs, and negative plates connected to negative electrode tabs, respectively; A first winding step of winding one end of each of the two or more pairs of insulating separators on the winding shaft; An electrode plate interposing step of alternately interposing a positive electrode plate and a negative electrode plate between the separators; And And a second winding step of winding the separators, the positive electrode plates, and the negative electrode plates together. The method of claim 5, wherein And a winding shaft removing step of removing the winding shaft after the second winding step. The method of claim 6, And a space removing step of removing the space occupied by the winding shaft after the winding shaft removing step. The method of claim 5, wherein And a second electrode tab fixing step of fixing the positive electrode tabs to each other and fixing the negative electrode tabs to each other after the second winding step. The method according to any one of claims 5 to 8, The preparation step is a jelly roll electrode assembly manufacturing method comprising the step of connecting each positive electrode tab to one end of each positive electrode plate and connecting each negative electrode tab to one end of each negative electrode plate. The method according to any one of claims 5 to 8, The electrode plate interposing step includes disposing the positive electrode plates such that the positive electrode tabs face each other and disposing the negative electrode plates so that the negative electrode tabs face each other, but disposing the positive electrode plates and the negative electrode plates so that the positive electrode tabs and the negative electrode tabs are spaced apart from each other. Jelly roll type electrode assembly manufacturing method characterized in that.