CN110802672B - Apparatus for punching electrode plate of battery - Google Patents

Abstract

A device for punching an electrode plate of a battery is disclosed, which can prevent a coating layer from falling off an electrode current collector by means of protrusions provided on the punching die. To this end, the device comprises: guide rollers, which convey the electrode plate including the electrode current collector and the coating layer; a die, which supports the electrode plate conveyed by the guide roller from below; The electrode plate is fixed between the die and the stripper; and the punch punches the fixed electrode plate protruding from one side surface of the die and one side surface of the stripper, wherein the die includes a top surface of the die and a portion of the die. A protrusion protrudes upward by a predetermined height at the end of the one side surface and the one side surface of the peeler adjacent to each other.

Description

Apparatus for punching electrode plate of battery

This application claims priority and benefit from and full benefit from korean patent application No. 10-2018-0091139, filed by the korean intellectual property office at 8/6/2018, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to an apparatus for punching electrode plates of a battery.

Background

A secondary battery is an electric power storage system capable of converting electric energy into chemical energy and storing the energy at a relatively high energy density. Unlike a primary battery, which is not generally charged any more, a secondary battery can be repeatedly recharged and is widely used for IT devices such as smart phones, cellular phones, notebook computers, or tablet PCs.

The secondary battery is manufactured by housing an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator located between the two electrode plates together with an electrolyte.

The electrode assembly may be formed by stacking two electrode plates and a separator and winding the stacked structure or by punching the electrode plates and stacking the punched electrode plates and the separator. Here, each of the positive and negative electrode plates may be formed by coating an active material on a foil-type current collector. The secondary battery may have a reduced capacity if the active material is released from the current collector during the punching of the electrode plate.

The above information disclosed in this background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Disclosure of Invention

Embodiments of the present invention provide an apparatus for punching an electrode plate of a battery, which can prevent a coating layer from falling off an electrode current collector by a protrusion, thereby suppressing a voltage drop and improving battery characteristics.

According to an aspect of the present invention, there is provided an apparatus for punching an electrode plate of a battery, the apparatus including: a guide roller conveying an electrode plate including an electrode current collector and a coating layer; a die for supporting the electrode plate transferred by the guide roller from below; a stripper which is positioned on the punching die and fixes the electrode plate between the punching die and the stripper while ascending and descending up and down; and a punch punching the fixed electrode plate protruding from one side surface of the die and one side surface of the stripper, wherein the die includes a protrusion protruding upward at an end portion of a top surface of the die adjacent to the one side surface of the die and the one side surface of the stripper.

The height of the protrusion from the top surface of the die may be in the range of 0.001mm to 1 mm.

The width of the protrusion, which is a length from the one side surface of the die in the first direction, may be in a range of 0.1mm to 5 mm.

The protrusion may have a top surface parallel to the top surface of the die and an inclined surface connecting the top surface of the protrusion with the top surface of the die.

The angle of the inclined surface of the protrusion may be in the range of 5 to 45 degrees.

The protrusion has a curved edge between the top surface and the inclined surface.

The radius of curvature of the edge may be in the range 0.1mm to 0.5 mm.

The protrusion may extend along an end of the top surface of the die to have a predetermined height and a predetermined width.

The stripper may have a flat planar bottom surface with the protrusion closer to the flat planar bottom surface than the top surface of the die.

As described above, the electrode plate punching apparatus according to the present invention can compress the fixing region of the electrode plate more than other regions by the protrusion provided at one end of the top surface of the die, thereby preventing the coating layer from falling off from the electrode current collector during punching of the electrode plate at the punching line of the electrode plate.

Drawings

Fig. 1 is a view showing the configuration of an apparatus for punching electrode plates of a battery according to the present invention.

Fig. 2A to 2C are views sequentially showing a punching process of the electrode plate punching apparatus shown in fig. 1.

Fig. 3A and 3B are an enlarged perspective view and an enlarged sectional view illustrating a portion of a die in the electrode plate punching device shown in fig. 1.

Fig. 4 is a perspective view showing another example of the die shown in fig. 3A.

Fig. 5A and 5B show a press line of an electrode plate pressed by the electrode plate pressing apparatus shown in fig. 1 and a press line of an electrode plate of a comparative example.

Detailed Description

Hereinafter, example embodiments of the invention will be described in detail with reference to the accompanying drawings.

The various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments disclosed are provided so that this disclosure will be thorough and complete and will convey the disclosed inventive concepts to those skilled in the art.

In addition, in the drawings, the size or thickness of various components may be exaggerated for clarity and conciseness. Like numbers refer to like elements throughout. In addition, it will be understood that when element a is referred to as being "connected to" element B, element a can be directly connected to element B or intervening elements C may be present, and element a and element B are indirectly connected to one another.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, for example, a first element, component, or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.

Referring to fig. 1, there is shown a view illustrating the construction of an apparatus for punching an electrode plate of a battery according to the present invention. Referring to fig. 2A to 2C, there are sequentially shown views illustrating a punching process of the electrode plate punching apparatus shown in fig. 1. Referring to fig. 3A and 3B, there are shown an enlarged perspective view and an enlarged sectional view illustrating a portion of a die in the electrode plate punching device shown in fig. 1.

As shown in fig. 1, the electrode plate punching apparatus may include a guide roller 110, a die 120, a stripper 130, and a punch 140. In the electrode plate punching apparatus 100, if the plate-shaped electrode plate 10 is fed between the die 120 and the stripper 130, the punch 140 descends to cut the electrode plate 10.

First, the guide roller 110 may include at least two or more guide rollers and allow the electrode plate 10 to be fed in the form of a film between the die 120 and the stripper 130 while having a constant tension. That is, the guide roller 110 may transfer the electrode plate 10 with a constant tension. The electrode plate 10 may be continuously fed between the die 120 and the stripper 130 in the first direction a by means of the guide roller 110. Here, the first direction a denotes a direction in which the electrode plate 10 is supplied.

The guide roller 110 may be disposed in front of the die 120 and the stripper 130, and the punch 140 may be disposed behind the die 120 and the stripper 130. That is, based on the die 120 and the stripper 130, the guide roller 110 and the punch 140 may be located at opposite sides in the first direction a.

Here, the electrode plate 10 may be a positive electrode plate or a negative electrode plate for a battery. The electrode plate 10 may include an electrode collector 11 and a coating layer 12, the electrode collector 11 being a thin metal sheet (e.g., a known metal foil), the coating layer 12 having a slurry including an active material coated on at least one surface of the electrode collector 11. If the electrode plate 10 is a positive electrode plate, aluminum or nickel may be used for the electrode collector 11, and a transition metal oxide may be used as the positive electrode active material of the coating layer 12. If the electrode plate 10 is a negative electrode plate, copper, a copper alloy, nickel, or a nickel alloy may be used for the electrode collector 11, and graphite or carbon may be used as the negative electrode active material of the coating layer 12. In addition, although the electrode plate 10 including the coating layers 12 on both surfaces of the electrode collector 11 is shown in the present invention, the coating layers 12 may be only on at least one surface, but aspects of the present invention are not limited thereto.

In addition, the electrode plate 10 may be wound in a roll configuration and may be supplied to the electrode plate punching apparatus 100. The electrode plate 10 may be supplied to the guide roller 110 from a member (not shown) supporting and fixing the electrode plate 10.

The die 120 may support the electrode plate 10 moved by the guide roller 110 from below. That is, the electrode plate 10 may be moved by the guide roller 110 in a state in which the bottom surface of the electrode plate 10 is in contact with the top surface 121 of the die 120. In addition, although not shown, a side or lower region of the die 120 may be fixed to the electrode plate punching apparatus 100. The specific configuration of the die 120 will be described in detail below.

Stripper 130 may be located on die 120. Here, the bottom surface 131 of the stripper 130 may face the die top surface 121 and may be a flat plane. The stripper 130 may fix the continuously supplied electrode plate 10 to the die 120 while ascending and descending. The stripper 130 is mounted to be raised and lowered by means of a common drive means (not shown), such as a hydraulic or pneumatic cylinder. Although the stripper 130 having a rectangular shape is illustrated, it may have any shape having a flat plane on a bottom surface thereof, but aspects of the present invention are not limited thereto. If the stripper 130 moves downward, the electrode plate 10 may be fixed between the die top surface 121 and the bottom surface 131 of the stripper 130. If the stripper 130 is moved upward, the electrode plate 10 may be moved along the die top surface 121 by the guide roller 110.

The punch 140 may move up and down along one side surface of the stripper 130 and one side surface of the die 120 and may punch the protruding electrode plate 10. Here, the electrode plate 10 may be fixed between the die 120 and the stripper 130. In addition, one side surface of the stripper 130 and one side surface of the die 120 may serve as a guide line for movement of the punch 140. As shown in fig. 2A to 2C, the punch 140 may punch the fixed electrode plate 10 protruding from one side surface of the die 120 and one side surface of the stripper 130. The punch 140 is installed to be elevated up and down by means of a general driving device (not shown) such as a hydraulic cylinder or a pneumatic cylinder.

As shown in fig. 3A and 3B, the die 120 has a substantially flat top surface 121 and a flat one side surface 123 bent in a substantially vertical direction from the die top surface 121. One side surface 123 may be a surface adjacent to the punch 140 and may function as a guide line during punching by the punch 140. In addition, the die 120 may further include a protrusion 122 protruding upward at an end of the die top surface 121 adjacent to the one side surface 123. Here, an end of the die top surface 121 adjacent to the one side surface 123 may be referred to as a top surface end of the die 120.

The protrusion 122 may have a protrusion top surface 122a extending parallel to the die top surface 121 and an inclined surface 122b connecting the protrusion top surface 122a with the die top surface 121.

The protrusion 122 may extend along the top surface end of the die 120 in the second direction B. Here, the second direction B may be a direction perpendicular to the first direction a in which the electrode plates 10 are supplied, preferably a direction of the width of the electrode plates 10 perpendicular to the first direction a. The protrusion 122 may protrude upward to have the same height at the entire end of the die top surface 121. In addition, the protrusions 122 may be closer to the bottom surface 131 of the stripper 130 than the die top surface 121. In addition, the fixing region 10a of the electrode plate 10 fixed between the die 120 and the stripper 130 may be more compressed than other regions by the protrusion 122. Here, the fixing region 10a of the electrode plate 10 denotes a portion of the electrode plate 10 fixed between the protrusion top surface 122a and the bottom surface 131 of the stripper 130 during the punching of the electrode plate 10. In addition, a region of the electrode plate 10 protruding from the fixing region 10a toward the punch 140 may be punched. That is, the fixing region 10a of the electrode plate 10 may be a region closest to the punching line 10b of the electrode plate 10 punched by the punch 140. Preferably, the pressing line 10b of the electrode plate 10 fixed between the die 120 and the stripper 130 may be located on the same line as one side surface 123 of the die 120.

Since the die 120 compresses the fixing region 10a of the electrode plate 10 more by the protrusion 122, the coating layer 12 on the press line 10b of the electrode plate 10 can be prevented from falling off the electrode collector 11.

The protrusion 122 may be disposed along the die top surface 121 to have a width W and a height H. Here, the width W of the protrusion 122 denotes a length from the one side surface 123 in the first direction a, and preferably a length of the protrusion top surface 122a in the first direction a. In addition, the height H of the protrusion 122 may represent a distance from the die top surface 121 to the protrusion top surface 122 a.

The width W of the protrusion 122 from the one side surface 123 may be in the range of 0.1mm to 5 mm. If the width W of the protrusion 122 is less than 0.1mm, the coating layer 12 on the press line 10b of the electrode plate 10 cannot be prevented from falling off from the electrode current collector 11 during the press of the electrode plate 10. In addition, if the width W of the protrusion 122 is greater than 5mm, since the pressure locally applied to the fixing region 10a of the electrode plate 10 may be reduced due to the increase in the width of the protrusion 122, resulting in a reduction in the compression ratio, it is not possible to prevent the coating layer 12 from falling off from the electrode current collector 11.

In addition, the height H of the protrusion 122 from the die top surface 121 may be in the range of 0.001mm to 1 mm. If the height H of the protrusion 122 is less than 0.001mm, the coating layer 12 on the press line 10b of the electrode plate 10 cannot be prevented from falling off from the electrode current collector 11 during pressing. In addition, if the height H of the protrusion 122 is greater than 1mm, the fixing region 10a of the electrode plate 10 may be deformed and damaged. More preferably, the height of the protrusion 122 may be in the range of 0.05mm to 0.1 mm.

The angle C of the inclined surface 122b of the protrusion 122 may be in the range of 5 degrees to 45 degrees. When the height H and the width W of the protrusion 122 are varied, the angle C of the inclined surface 122b of the protrusion 122 may be varied within the above-described range. The inclined surface 122b may be linear or may have a curved profile.

For example, as shown in fig. 3B, the inclined surface 122B of the protrusion 122 may be linear. For another example, as shown in fig. 4, the inclined surface 122b of the protrusion 122 may have a curved profile. If the inclined surface 122b of the protrusion 122 has a curved profile, the edge connecting the protrusion top surface 122a and the inclined surface 122b may be curved.

If the edges connecting the protrusion top surface 122a and the inclined surface 122b are curved as described above, the radius of curvature of the curved edges may be in the range of 0.1mm to 5 mm.

Referring to fig. 5A, a photographed image of a punching line 10B of the electrode plate 10 punched by the electrode plate punching apparatus 100 shown in fig. 1 is shown, and referring to fig. 5B, a photographed image of a punching line 20B of the electrode plate 20 punched by a die without a protrusion (comparative example) is shown.

Here, when the protrusion 122 has a width W of 1mm and a height H of 0.1mm and the electrode plate 10 is punched by the electrode plate punching apparatus 100, a photographed image of the electrode plate 10 shown in fig. 5A is obtained.

If the protrusion 122 is provided at one end of the top surface 121 of the die 120, as shown in fig. 5A, the fixing region 10a of the electrode plate 10 is compressed more than other regions of the electrode plate 10 by the protrusion 122. Therefore, the coating layer 12 on the press line 10b of the electrode plate 10 may be prevented from falling off from the electrode collector 11 during pressing. In contrast, if the die has a flat top surface without protrusions, the coating layer 22 on the punching line 20B of the electrode plate 20 is peeled off from the electrode collector 21 during punching, as shown in fig. 5B.

As described above, when the electrode plate 10 is punched according to the electrode plate punching apparatus 100 of the present invention, the coating layer 12 can be prevented from falling off the electrode current collector 11 by the protrusion 122, thereby suppressing a voltage drop of the battery and improving battery characteristics.

While the electrode plate punching apparatus of the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims (9)

1. A device for punching an electrode plate of a battery, the device comprising: Guide rollers to transport electrode plates including electrode current collectors and coating layers; A die that supports from below the electrode plates conveyed by guide rollers; a stripper that is positioned on the die and that lifts up and down while fixing the electrode plate between the die and the stripper; and A punch that punches a fixed electrode plate protruding from one side surface of the die and one side surface of the stripper, Wherein, the die includes a protrusion protruding upward at an end of the top surface of the die adjacent to the one side surface of the die and the one side surface of the stripper. 2. The apparatus of claim 1, wherein the height of the protrusion from the top surface of the die is in the range of 0.001 mm to 1 mm. 3. The apparatus of claim 1, wherein the protrusion has a width in the range of 0.1 mm to 5 mm, the width being a length from the one side surface of the die in a first direction, the first direction is a direction perpendicular to the one side surface of the die. 4. The apparatus of claim 1, wherein the protrusion has a top surface parallel to the top surface of the die and an inclined surface connecting the top surface of the protrusion with the top surface of the die. 5. The device of claim 4, wherein the angle of the inclined surface of the protrusion is in the range of 5 degrees to 45 degrees. 6. The device of claim 4, wherein the protrusion has a curved edge between the top surface and the inclined surface. 7. The device of claim 6, wherein the radius of curvature of the edge is in the range of 0.1 mm to 5 mm. 8. The apparatus of claim 1, wherein the protrusion extends along the end of the top surface of the die to have a predetermined height and a predetermined width. 9. The apparatus of claim 1, wherein the stripper has a flat, planar-shaped bottom surface, and the protrusion is closer to the flat, planar-shaped bottom surface than a top surface of the die.

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