Bead forming system for battery cell

Abstract

The present invention relates to a bead forming system for a battery cell, the bead forming system being for forming a beading part in a cylindrical battery case. The bead forming system for a battery cell comprises: a main rotary in which a plurality of holders are disposed along the edge to support a battery case; a bead forming device for forming a beading part in the battery case supported by the plurality of holders of the main rotary; a dummy cell supply rotary for supplying dummy cells to the plurality of holders of the main rotary to remove foreign substances of the bead forming device; a dummy cell withdrawal rotary for recovering the dummy cells supplied to the plurality of holders of the main rotary; and a dummy cell cleaning device for cleaning the dummy cells withdrawn by the dummy cell withdrawal rotary and transmitting the dummy cells to the dummy cell supply rotary.

Description

Bead molding system for battery cells

[0001] The present invention relates to a bead forming system for a battery cell used in the manufacture of a cylindrical battery cell.

[0002] Secondary batteries, which offer high applicability across product lines and possess electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric driving sources.

[0003] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy.

[0004] Conventionally, nickel-cadmium batteries or nickel-hydrogen batteries were widely used as secondary batteries; however, recently, lithium secondary batteries are being widely used because they exhibit almost no memory effect compared to nickel-based secondary batteries, allowing for free charging and discharging, have a very low self-discharge rate, and high energy density.

[0005] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0006] Generally, secondary batteries can be classified according to the shape of the casing into cylindrical battery cells in which the electrode assembly is embedded in a metal can, and pouch-type battery cells in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0007] For example, a cylindrical secondary battery is manufactured by inserting a jelly-roll type electrode assembly into a cylindrical battery case, forming a ring-shaped groove called a bead in the cylindrical battery case corresponding to the upper outer surface of the jelly-roll, installing a battery cap equipped with a gasket on the bead, and then clamping the top of the cylindrical battery case.

[0008] The bead formation process involves creating a ring-shaped groove on the upper surface of a cylindrical battery case by applying pressure to the side of the cylindrical battery case with a beading knife. However, when the beading knife applies pressure to the side of the cylindrical battery case to form the bead, a large amount of foreign matter is generated, and this foreign matter acts as a cause of contamination of the cylindrical secondary battery.

[0009] Therefore, effectively removing foreign substances generated during the beading process in the manufacturing of cylindrical secondary batteries is crucial for the quality control of secondary batteries.

[0010] However, in the case of conventional bead forming devices, suction is not effectively performed during the beading process, so the removal of foreign matter is not sufficiently achieved.

[0011] The present invention provides a bead molding system for battery cells that can effectively remove foreign substances generated during the beading process for manufacturing battery cells.

[0012] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description of the invention below.

[0013] A bead forming system for a battery cell according to an embodiment of the present invention for solving the above-described problem is for forming a beading portion in a cylindrical battery case. The bead forming system for a battery cell comprises a main rotary having a plurality of holders arranged along the edge to support the battery case, a bead forming device for forming a beading portion in the battery case supported by the plurality of holders of the main rotary, a dummy cell supply rotary for supplying dummy cells to the plurality of holders of the main rotary to remove foreign substances from the bead forming device, a dummy cell withdrawal rotary for recovering the dummy cells supplied to the plurality of holders of the main rotary, and a dummy cell cleaning device for cleaning the dummy cells withdrawn by the dummy cell withdrawal rotary and transferring them to the dummy cell supply rotary.

[0014] The above dummy cell supply rotary can be configured to periodically supply the dummy cells to the plurality of holders of the main rotary.

[0015] Depending on the rotation of the main rotary, the dummy cell supply rotary may be configured to supply the dummy cells to the plurality of holders of the main rotary while rotating in a direction opposite to the rotation direction of the main rotary, and the dummy cell withdrawal rotary may be configured to retrieve the dummy cells from the plurality of holders of the main rotary while rotating in a direction opposite to the rotation direction of the main rotary.

[0016] The holder can rotatably support the battery case and the dummy cell.

[0017] The bead forming device may include a beading knife that presses the side of the battery case or the dummy cell supported by the holder when the holder rotates the battery case or the dummy cell, and a backup roller located on the opposite side of the beading knife with the battery case or the dummy cell in between.

[0018] The dummy cell supported by the holder after being supplied to the main rotary may be configured to remove foreign matter by contacting the beading knife and the backup roller of the bead forming device.

[0019] The above dummy cell may include a cylindrical dummy cell body and a foreign matter removal ring made of silicone rubber that is detachably coupled to the dummy cell body.

[0020] A foreign matter removal ring receiving groove into which the foreign matter removal ring is fitted may be formed on one side of the above dummy cell body.

[0021] When the above dummy cell is supported by the plurality of holders of the above main rotary, the foreign matter removal ring can be configured to come into contact with the bead forming device.

[0022] The above dummy cell cleaning device may include a transfer unit that transfers the dummy cell from the dummy cell withdrawal rotary to the dummy cell supply rotary, and a cleaning unit that cleans the dummy cell moving along the transfer unit.

[0023] Additionally, the transfer unit may include a conveyor belt that moves the dummy cell received from the dummy cell withdrawal rotary, and a supply disk that rotates in accordance with the rotation of the dummy cell supply rotary and transfers the dummy cell moved by the conveyor belt to the dummy cell supply rotary.

[0024] According to the present invention, foreign substances generated during the beading process for manufacturing a battery cell can be effectively removed.

[0025] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by a person skilled in the art from the description of the invention below.

[0026] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0027] FIG. 1 is a drawing for explaining a battery cell in a manufacturing process including a battery case in which a bead is formed through a bead molding system for a battery cell according to one embodiment of the present invention.

[0028] FIG. 2 is a drawing for explaining a bead molding system for a battery cell according to one embodiment of the present invention.

[0029] FIG. 3 is a perspective view showing the holder of the main rotary and the beading knife and backup roller of the bead forming device used in a bead forming system for a battery cell according to one embodiment of the present invention.

[0030] FIG. 4 is a perspective view showing a dummy cell used in a bead molding system for a battery cell according to one embodiment of the present invention.

[0031] FIG. 5 is a cross-sectional view showing a dummy cell used in a bead molding system for a battery cell according to one embodiment of the present invention.

[0032] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid the present invention being interpreted ambiguously. Throughout the specification, like reference numerals refer to like components.

[0033] In drawings, thicknesses may be enlarged to clearly represent multiple layers and regions. Throughout the specification, the same reference numerals are used for similar parts. When a part such as a layer, film, region, or plate is described as being "above" another part, this includes not only cases where it is "immediately above" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately above" another part, it may mean that there is no other part in between. Furthermore, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only cases where it is "immediately below" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately below" another part, it may mean that there is no other part in between.

[0034] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0035] Hereinafter, a bead forming system (101) for a battery cell according to one embodiment of the present invention will be described. The bead forming system (101) for a battery cell according to one embodiment of the present invention is for forming a beading portion (54) on a cylindrical battery case (50).

[0036] Before describing the bead molding system (101) for a battery cell according to one embodiment of the present invention, we will first describe a battery cell (100) in a manufacturing process including a battery case (50) in which a beading portion (54) is formed through the bead molding system (101) for a battery cell according to one embodiment of the present invention, with reference to FIG. 1.

[0037] FIG. 1 exemplarily illustrates a beading portion (54) formed on a battery case (50) through a bead molding system (101) for a battery cell according to one embodiment of the present invention. FIG. 1 shows a cylindrical battery cell (100) in an unfinished state during the manufacturing process.

[0038] As illustrated in FIG. 1, the battery cell (100) may include an electrode assembly (10), a battery case (50), and a current collector (40).

[0039] The electrode assembly (10) may be a jelly roll type electrode assembly having a winding center hole formed in the center.

[0040] The battery case (50) may be configured to be cylindrical to accommodate the electrode assembly (10) through an opening formed at one end. The battery case (50) may include a beading portion (54) formed by a centripetal indentation near the open end.

[0041] This beading portion (54) can be formed by pressing the outer circumference of the battery case (50) and is formed so that an electrode assembly (10), which can have a size corresponding to the width of the battery case (50), does not come out through an opening formed at one end of the battery case (50).

[0042] The current collector (40) may include a negative current collector connected to a negative non-negative portion provided on the negative electrode of the electrode assembly (10), and a positive current collector connected to a positive non-negative portion provided on the positive electrode of the electrode assembly.

[0043] The current collector (40) illustrated exemplarily in FIG. 1 is a negative current collector. The negative current collector (40) can be coupled to the open-side end of the electrode assembly (10). The current collector (40) can be electrically connected to the battery case (50). Here, the current collector (40) can be coupled to the beading portion (54) of the battery case (50) by laser welding.

[0044] In this way, the electric case (50) connected to the current collector (40) functions as a negative terminal. That is, the battery case (50) can have the same polarity as the negative electrode of the electrode assembly (10). To this end, the battery case (50) can be made of a material having conductivity such as metal. The material of the battery case (50) can be made of a conductive metal, such as aluminum, steel, stainless steel, etc., but is not limited thereto.

[0045] Meanwhile, a positive current collector not shown in FIG. 1 can be connected to a positive non-positive portion provided on the positive of the electrode assembly (10) at the opposite side of the cylindrical battery cell (100), that is, at the bottom of the electrode assembly (10).

[0046] Referring to FIGS. 2 to 5, a bead molding system (101) for a battery cell according to one embodiment of the present invention will be described.

[0047] FIG. 2 is a configuration diagram for explaining a bead forming system (101) for a battery cell according to one embodiment of the present invention. FIG. 3 is a perspective view showing the holder (210) of the main rotary (200), the beading knife (510) and the backup roller (520) of the bead forming device (500). FIG. 4 and FIG. 5 are drawings for explaining a dummy cell (150) used in the bead forming system (101) for a battery cell according to one embodiment of the present invention.

[0048] As illustrated in FIGS. 2 and 3, a bead forming system (101) for a battery cell according to one embodiment of the present invention includes a main rotary (200), a bead forming device (500), a dummy cell supply rotary (310), a dummy cell withdrawal rotary (320), and a dummy cell cleaning device (400).

[0049] The main rotary (200) can form a beading portion (54) on the battery case (50) while rotating the battery case (50) of a plurality of battery cells (100). A plurality of holders (210) are arranged along the edge of the main rotary (200) to support the battery case (50).

[0050] In addition, the multiple holders (210) of the main rotary (200) can support a dummy cell (150) in addition to the battery case (50) of the battery cell (100).

[0051] Additionally, a plurality of holders (210) can rotatably support the battery case (50) or dummy cell (150) of the battery cell (100). That is, the battery case (50) or dummy cell (150) of the battery cell (100) supported by the plurality of holders (210) can rotate.

[0052] The bead forming device (500) can form a beading portion (54) on the battery case (50) of a battery cell (100) supported by a plurality of holders (210) of the main rotary (200).

[0053] Specifically, the bead forming device (500) may include a beading knife (510) and a backup roller (520).

[0054] The beading knife (510) can form a beading portion (54) on the battery case (50) by pressing the battery case (50) supported by the holder (210) when the holder (210) supports and rotates the battery case (50) of the battery cell (100).

[0055] Additionally, when the holder (210) supports and rotates the dummy cell (150), the beading knife (510) comes into contact with the foreign matter removal ring (155) of the dummy cell (150), which is supported by the holder (210) and will be described later, thereby transferring the foreign matter.

[0056] The backup roller (520) may be positioned on the opposite side of the beading knife (510) with the battery case (50) or dummy cell (150) of the battery cell (100) in between. The backup roller (520) supports the battery case (50) or dummy cell (150) on the opposite side when the beading knife (510) presses the side of the battery case (50) or dummy cell (150) of the battery cell (100). At this time, the backup roller (520) rotates in the opposite direction to the rotational direction of the battery case (50) or dummy cell (150).

[0057] As described above, when the beading knife (510) presses the side of the battery case (50) of the battery cell (100) to form the beading portion (54), a large amount of foreign matter is generated.

[0058] The dummy cell supply rotary (310) supplies dummy cells (150) to a plurality of holders (210) of the main rotary (200) to remove foreign substances generated in the bead forming device (500) during the bead forming process.

[0059] Specifically, the dummy cell supply rotary (310) can supply dummy cells (150) to a plurality of holders (210) of the main rotary (200) while rotating in a direction opposite to the rotation direction of the main rotary (200) according to the rotation of the main rotary (200).

[0060] At this time, the dummy cell supply rotary (310) can periodically supply dummy cells (150) to a plurality of holders (210) of the main rotary (200). That is, after the battery case (50) of the battery cell (100) is supplied to the main rotary (200) and the bead forming process proceeds for a certain period of time, the supply of the battery case (50) of the battery cell (100) to the main rotary (200) is stopped, and dummy cells (150) are supplied to the holders (210) of the main rotary (200) through the dummy cell supply rotary (310) to remove foreign substances generated in the bead forming device (500). Then, when the foreign substances generated in the bead forming device (500) are sufficiently removed after the dummy cells (150) are supplied, the dummy cell supply rotary (310) stops supplying dummy cells (150) to the holders (210) of the main rotary (200).

[0061] Additionally, the cycle in which the dummy cell supply rotary (310) supplies dummy cells (150) to the main rotary (200) can be set differently depending on the size of the battery cell (100) and the specifications of the bead forming system (101) for the battery cell.

[0062] In this way, the dummy cell (150), which is supplied to the main rotary (200) through the dummy cell supply rotary (310) and supported by the holder (210), comes into contact with the beading knife (510) and backup roller (520) of the bead forming device (500) to remove foreign matter adhering to the beading knife (510) and backup roller (520).

[0063] The dummy cell extraction rotary (320) retrieves dummy cells (150) supplied to a plurality of holders (210) of the main rotary (200).

[0064] Specifically, the dummy cell extraction rotary (320) can retrieve dummy cells (150) from a plurality of holders (210) of the main rotary (200) while rotating in a direction opposite to the rotation direction of the main rotary (200) according to the rotation of the main rotary (200).

[0065] The dummy cell cleaning device (400) washes the dummy cell (150) withdrawn by the dummy cell withdrawal rotary (320) and then transfers it back to the dummy cell supply rotary (310).

[0066] Specifically, the dummy cell cleaning device (400) may include a transfer unit (410) and a cleaning unit (450).

[0067] The transfer unit (410) can transfer dummy cells (150) from the dummy cell withdrawal rotary (320) to the dummy cell supply rotary (310).

[0068] For example, the transfer unit (410) may include a conveyor belt (411) that moves a dummy cell received from a dummy cell extraction rotary (320), and a supply disk (412) that rotates together with the rotation of the dummy cell supply rotary (310) and transfers the dummy cell (150) moved by the conveyor belt (411) to the dummy cell supply rotary (310).

[0069] The cleaning unit (450) can clean the dummy cell (150) moving along the transfer unit (410).

[0070] Specifically, the cleaning unit (450) can clean a dummy cell (150) moving along a conveyor belt (411), and if the cleaning unit (450) is wet, it may include a dryer for drying the dummy cell (150).

[0071] With this structure, the dummy cell cleaning device (400) can automatically clean the dummy cell (150) that was supplied to the main rotary (200) after retrieving it and supply it back to the main rotary (200). That is, there is no need to replace the dummy cell (150) or stop the operation of the battery cell bead molding system (101) for cleaning the dummy cell (150).

[0072] Accordingly, the bead forming system (101) for a battery cell according to one embodiment of the present invention can not only prevent defects caused by foreign substances during the bead forming process but also improve the speed of the bead forming process.

[0073] Referring to FIGS. 4 and 5, the dummy cell (150) may include a cylindrical dummy cell body (151) and a foreign matter removal ring (155) made of silicone rubber that is detachably coupled to the dummy cell body (151). At this time, a foreign matter removal ring receiving groove (152) into which the foreign matter removal ring (155) is fitted may be formed on one side of the dummy cell body (151). Accordingly, if the foreign matter removal ring (155) fails to perform its function or becomes damaged due to repeated use, the foreign matter removal ring (155) can be detached from the dummy cell body (151) and replaced.

[0074] When a dummy cell (150) of such a structure is supported by a plurality of holders (210) of the main rotary (200) and rotates, the foreign matter removal ring (155) comes into contact with the beading knife (510) and backup roller (520) of the bead forming device (500) and removes foreign matter adhering to the beading knife (510) and backup roller (520). Since the foreign matter removal ring (155) is made of silicone rubber and has a higher adhesive force to foreign matter than the beading knife (510) and backup roller (520), foreign matter adhering to the beading knife (510) and backup roller (520) can easily adhere to the foreign matter removal ring (155).

[0075] According to this configuration, foreign substances generated during the beading process for manufacturing the battery cell (100) can be effectively removed.

[0076] Additionally, since the dummy cell cleaning device (400) can automatically clean the dummy cell (150) that was supplied to the main rotary (200) after retrieving it and supply it back to the main rotary (200), there is no need to replace the dummy cell (150) or stop the operation of the battery cell bead molding system (101) for cleaning the dummy cell (150).

[0077] Accordingly, the bead forming system (101) for a battery cell according to one embodiment of the present invention can not only prevent defects caused by foreign substances during the bead forming process but also improve the speed of the bead forming process.

[0078] Meanwhile, although terms indicating direction such as up and down have been used in this specification, these terms are used merely for convenience of explanation, and it is obvious to a person skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0079] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0080] < Explanation of Symbols >

[0081] 100: Battery cell

[0082] 101: Bead molding system for battery cells

[0083] 150: Dummy cell

[0084] 151: Dummy cell body

[0085] 152: Foreign matter removal ring receiving groove

[0086] 155: Foreign matter removal ring

[0087] 200: Main Rotary

[0088] 210: Holder

[0089] 310: Dummy cell supply rotary

[0090] 320: Dummy Cell Withdrawal Rotary

[0091] 400: Dummy cell cleaning device

[0092] 410: Transfer unit

[0093] 411: Conveyor belt

[0094] 412: Supply disk

[0095] 450: Tax Administration

[0096] 500: Bead forming device

[0097] 510: Beading knife

[0098] 520: Backup Roller

[0099] The present invention can be used to provide a bead molding system for battery cells that can effectively remove foreign substances generated during the beading process for manufacturing battery cells.

Claims

1. A bead forming system for a battery cell for forming a beading portion in a cylindrical battery case, A main rotary with multiple holders arranged along the edges to support the battery case; A bead forming device for forming a beading portion on a battery case supported by the plurality of holders of the main rotary above; A dummy cell supply rotary for supplying dummy cells to the plurality of holders of the main rotary to remove foreign substances from the bead forming device; A dummy cell extraction rotary for recovering the dummy cells supplied to the plurality of holders of the main rotary; and A dummy cell cleaning device that cleans the dummy cell withdrawn by the dummy cell withdrawal rotary and transfers it to the dummy cell supply rotary. A bead molding system for battery cells including 2. In Paragraph 1, A bead forming system for a battery cell, characterized in that the above dummy cell supply rotary periodically supplies the dummy cells to the plurality of holders of the above main rotary.

3. In Paragraph 1, According to the rotation of the above main rotary, The above dummy cell supply rotary rotates in a direction opposite to the rotation direction of the main rotary and supplies the dummy cells to the plurality of holders of the main rotary, and A battery cell bead forming system characterized by the above-mentioned dummy cell extraction rotary retrieving the dummy cells from the plurality of holders of the main rotary while rotating in a direction opposite to the rotation direction of the main rotary.

4. In Paragraph 1, A bead forming system for a battery cell, characterized in that the holder rotatably supports the battery case and the dummy cell.

5. In Paragraph 4, The above bead forming device is, A beading knife that presses the side surface of the battery case or the dummy cell supported by the holder when the holder rotates the battery case or the dummy cell; and A backup roller located on the opposite side of the beading knife, with the battery case or the dummy cell in between. A bead molding system for a battery cell characterized by including 6. In Paragraph 5, A bead forming system for a battery cell, characterized in that the dummy cell, supported by the holder after being supplied to the main rotary, comes into contact with the beading knife and the backup roller of the bead forming device to remove foreign matter.

7. In Paragraph 1, The above dummy cell is, Cylindrical dummy cell body; A foreign matter removal ring made of silicone rubber and detachably coupled to the above-mentioned dummy cell body. A bead molding system for a battery cell characterized by including 8. In Paragraph 7, A bead molding system for a battery cell, characterized in that a foreign matter removal ring receiving groove into which the foreign matter removal ring is fitted is formed on one side of the dummy cell body.

9. In Paragraph 7, A bead forming system for a battery cell, characterized in that when the dummy cell is supported by the plurality of holders of the main rotary, the foreign matter removal ring contacts the bead forming device.

10. In Paragraph 1, The above dummy cell cleaning device is, A transfer unit that transfers the dummy cell from the dummy cell withdrawal rotary to the dummy cell supply rotary; A cleaning unit that cleans the dummy cell moving along the above transfer unit. A bead molding system for a battery cell characterized by including 11. In Paragraph 10, The above transfer unit is, A conveyor belt for moving the dummy cell received from the above dummy cell extraction rotary; A supply disc that rotates in accordance with the rotation of the dummy cell supply rotary and transfers the dummy cells moved by the conveyor belt to the dummy cell supply rotary. A bead molding system for a battery cell characterized by including

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