Battery cell gripper and jig device comprising same

Abstract

The present invention relates to a battery cell gripper for gripping a cylindrical battery cell, and a jig device comprising same. The battery cell gripper, according to an embodiment of the present invention, includes: a holder for clamping the side surface of a cylindrical battery cell; and a first direction transfer unit for transferring the holder in a first direction which connects both base surfaces of the cylindrical battery cell.

Description

Battery cell gripper and jig device including the same

[0001] The present invention relates to a battery cell gripper for clamping a cylindrical battery cell when welding an electrode assembly and a current collector plate included in a cylindrical battery cell, and a jig device including the same.

[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] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack and the electrical connection type can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, cylindrical, prismatic, and pouch-type battery cells are known as types of unit secondary battery cells. In the case of a cylindrical battery cell, a separator acting as an insulator is interposed between the positive and negative electrodes, and this is wound to form a jellyroll-shaped electrode assembly, which is then inserted into a battery case to constitute the battery. Additionally, a current collection plate may be connected to the unoccupied portions of the positive and negative electrodes, respectively, and the current collection plate electrically connects the electrode assembly with the electrode terminals exposed to the outside. For reference, the positive terminal may be a cap plate of a sealing body that seals the opening of the battery case, and the negative terminal may be the battery case. However, according to conventional cylindrical battery cells having such a structure, current is concentrated in the strip-shaped electrode tabs connected to the unoccupied portions of the positive or negative electrodes, resulting in high resistance, excessive heat generation, and poor current collection efficiency.

[0006] Generally, resistance and heat generation are not major issues for small cylindrical battery cells; however, if the form factor is increased for application in electric vehicles, a problem may arise where the cylindrical battery cells ignite due to the significant heat generated around the electrode tabs during rapid charging.

[0007] To solve these problems, a cylindrical battery cell with an improved current collection efficiency was developed by designing a jellyroll-type electrode assembly such that an anode-free section and a cathode-free section are located at the top and bottom, respectively, and welding a current collection plate to these non-parts.

[0008] In this structure, welding of the foil-shaped uncoated portion and the current collector plate is essential. However, as the shape of the current collector plate welded to the positive side and the current collector plate welded to the negative side differs, a welding process suitable for those shapes is required, and if the cylindrical battery cell moves during welding, deviations in the welding angle and welding position may occur.

[0009] Accordingly, the present invention provides a battery cell gripper for stably clamping a cylindrical battery cell during welding of an electrode assembly and a current collector plate.

[0010] In addition, the present invention provides a jig device including the aforementioned battery cell gripper.

[0011] 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.

[0012] According to an embodiment of the present invention, a battery cell gripper for gripping a cylindrical battery cell includes a holder for clamping the side surface of the cylindrical battery cell and a first direction transfer unit for moving the holder in a first direction connecting the bottom surfaces of both sides of the cylindrical battery cell.

[0013] The first direction transfer unit may include one of a linear motor or a ball screw motor.

[0014] The above holder may include at least one pair of gripping fingers facing each other with a cylindrical battery cell in between.

[0015] In addition, a curved gripping groove may be formed in the area where the pair of gripping fingers come into contact with the cylindrical battery cell.

[0016] The above gripping groove can be formed in a shape corresponding to the curved surface of the side of the cylindrical battery cell.

[0017] In addition, the battery cell gripper described above may further include a second direction transfer unit that adjusts the distance between the pair of gripping fingers.

[0018] The above second direction transfer unit may include one of a linear motor or a ball screw motor.

[0019] Additionally, the holder may include a pair of first gripping fingers facing each other with a cylindrical battery cell in between, and a pair of second gripping fingers spaced apart from the pair of first gripping fingers in the first direction and facing each other with a cylindrical battery cell in between.

[0020] In addition, according to an embodiment of the present invention, a jig device for clamping a cylindrical battery cell during welding of an electrode assembly and a contact plate comprises a base, a battery cell gripper provided on the base and clamping a side surface of the cylindrical battery cell, and one or more welding masks provided on the base and in contact with at least one bottom surface of the cylindrical battery cell. The battery cell gripper comprises a holder that clamps a side surface of the cylindrical battery cell and a first direction transfer unit that transfers the holder in a first direction so that at least one bottom surface of the cylindrical battery cell comes into close contact with the one or more welding masks.

[0021] The first direction transfer unit of the battery cell gripper may include one of a linear motor or a ball screw motor.

[0022] The holder of the battery cell gripper may include at least one pair of gripping fingers facing each other with the cylindrical battery cell in between.

[0023] A curved gripping groove may be formed in the area where the above pair of gripping fingers come into contact with the cylindrical battery cell.

[0024] The above gripping groove can be formed in a shape corresponding to the curved surface of the side of the cylindrical battery cell.

[0025] The above-described jig device may further include a second direction transfer unit that adjusts the spacing between the pair of gripping fingers of the battery cell gripper.

[0026] The second direction transfer unit of the battery cell gripper may include one of a linear motor or a ball screw motor.

[0027] The holder of the battery cell gripper may include a pair of first gripping fingers facing each other with a cylindrical battery cell in between, and a pair of second gripping fingers spaced apart from the pair of first gripping fingers in the first direction and facing each other with a cylindrical battery cell in between.

[0028] According to the present invention, a cylindrical battery cell can be stably clamped during welding of an electrode assembly and a current collection plate.

[0029] 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.

[0030] FIG. 1 shows an exemplary form of a cylindrical battery cell that is gripped by a battery cell gripper and a jig device including the same, according to one embodiment of the present invention.

[0031] FIG. 2 is a drawing for explaining a battery cell gripper and a jig device including the same according to an embodiment of the present invention.

[0032] Figures 3 and 4 are drawings for explaining the operating state of the battery cell gripper of Figure 1.

[0033] 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.

[0034] In the drawings, thicknesses have been enlarged to clearly represent various layers and regions. Throughout the specification, the same reference numerals have been 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 means 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 means that there is no other part in between.

[0035] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0036]

[0037] A battery cell gripper (501) and a jig device (101) including the same according to one embodiment of the present invention are for stably clamping a cylindrical battery cell (100) during welding of an electrode assembly (10) and a current collection plate (40).

[0038] Before describing the battery cell gripper (501) and the jig device (101) including the same according to one embodiment of the present invention, first, with reference to FIG. 1, we will describe an exemplary form of a cylindrical battery cell (100) that is gripped by the battery cell gripper (501) and the jig device (101) including the same according to one embodiment of the present invention during laser welding.

[0039] The cylindrical battery cell (100) illustrated in FIG. 1 represents an unfinished state during the manufacturing process. As illustrated in FIG. 1, the cylindrical battery cell (100) may include an electrode assembly (10), a battery case (50), and a current collection plate (40).

[0040] The electrode assembly (10) may be a jelly roll type electrode assembly having a winding center hole formed in the center.

[0041] The battery case (50) may be configured to accommodate an 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.

[0042] 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).

[0043] The current collector plate (40) may include a negative current collector plate connected to a negative electrode non-negative portion provided on the negative electrode of the electrode assembly (10), and an positive current collector plate connected to a positive electrode non-negative portion provided on the positive electrode of the electrode assembly.

[0044] Meanwhile, the current collection plate (40) illustrated exemplarily in FIG. 1 is a negative current collection plate. This current collection plate (40) can be coupled to the open-side end of the electrode assembly (10). The current collection plate (40) can be electrically connected to the battery case (50). Here, the current collection plate (40) can be coupled to the beading portion (54) of the battery case (50) by laser welding.

[0045] In this way, the electric case (50) connected to the current collection plate (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, or stainless steel, but is not limited thereto.

[0046] Meanwhile, a positive current collector plate 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).

[0047] Although a cylindrical battery cell (100) that is gripped by a battery cell gripper (501) and a jig device (101) including the same according to one embodiment of the present invention during a welding process has been described above, the cylindrical battery cell (100) that is gripped by the battery cell gripper (501) and the jig device (101) including the same according to one embodiment of the present invention is not necessarily limited to a cylindrical battery cell (100) having a structure as described above.

[0048]

[0049] Hereinafter, a battery cell gripper (501) and a jig device (101) including the same according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4.

[0050] Referring to FIG. 2, the jig device (101) includes a base (200), a battery cell gripper (501) according to one embodiment of the present invention, and a welding mask (400).

[0051] The base (200) can support the battery cell gripper (501) to be described later and the welding mask (400) to be described later. For example, a guide rail may be formed on the base (200) to assist in the movement of the second direction transfer unit (520) of the battery cell gripper (501) to be described later. That is, the second direction transfer unit (520) can move in the second direction along the guide rail formed on the base (200). Here, the guide rail may be made in various shapes and structures known to those skilled in the art to which the present invention belongs.

[0052] A welding mask (400) is provided on a base (200) so as to be in contact with at least one side bottom surface of a cylindrical battery cell (100). If a welding process is performed on both sides bottom surfaces of the cylindrical battery cell (100), the welding mask (40) may be provided on each side bottom surface of the cylindrical battery cell (100). Then, the welding mask (400) is pressed against one side bottom surface of the cylindrical battery cell (100) by a battery cell gripper (501) to be described later, and thus the welding mask (400) presses the current collection plate (40) against the welding portion of the electrode assembly (10).

[0053] In this way, the electrode assembly (10) and the current collection plate (40) of the cylindrical battery cell (100) are fixed using the welding mask (40) and the battery cell gripper (501) to be described later, so that transfer is performed without a separate loading and unloading procedure for welding, and on-the-fly welding can be performed quickly and accurately in a scanning manner through a laser welding machine.

[0054] For example, the welding mask (400) may be provided with an elongated hole. Then, a laser irradiated from a laser welder may move in a scanning manner along the length direction of the elongated hole of the welding mask (400) to proceed with welding. This laser welding may be performed by partially melting the welding area of ​​the current collector plate (40), or by interposing solder for welding between the current collector plate (40) and the beading portion (54) of the battery case (50).

[0055] A battery cell gripper (501) is provided on a base (200) and clamps the side of a cylindrical battery cell (100).

[0056] Specifically, the battery cell gripper (501) includes a holder (550) and a first direction transfer unit (510). Additionally, the battery cell gripper (501) may also include a second direction transfer unit (520).

[0057] The holder (550) clamps the side of the cylindrical battery cell (100). Specifically, the holder (550) may include at least one pair of gripping fingers (551, 552) facing each other with the cylindrical battery cell (100) in between.

[0058] In addition, a curved gripping groove (5515, 5525) may be formed in the area where at least one pair of gripping fingers (551, 552) come into contact with the cylindrical battery cell (100). At this time, the gripping groove (5515, 5525) may be formed in a shape corresponding to the curved surface of the side surface of the cylindrical battery cell (100). For example, the gripping groove (5515, 5525) may be formed in a groove shape having a radius of curvature equal to or slightly smaller than the radius of curvature of the curved surface of the side surface of the cylindrical battery cell (100). Here, forming the radius of curvature of the gripping groove (5515, 5525) slightly smaller is intended to allow the gripping fingers (551, 552) to grip the cylindrical battery cell (100) tightly.

[0059] Accordingly, the cylindrical battery cell (100) can be clamped by at least one pair of gripping fingers (551, 552) with a portion of the side surface of the cylindrical battery cell (100) being received in the gripping grooves (5515, 5525) of the gripping fingers (551, 552). That is, the at least one pair of gripping fingers (551, 552) can grip the cylindrical battery cell (100) having a curved surface more stably, thereby effectively preventing movement of the cylindrical battery cell (100) during welding.

[0060] Additionally, in one embodiment of the present invention, the gripping fingers (551, 552) may be replaced with different types of gripping fingers (551, 552) depending on the size of the cylindrical battery cell (100). For example, if the type of cylindrical battery cell (100) to be gripped by the jig device (101) changes, the gripping fingers (551, 552) may be replaced with different types of gripping fingers (551, 552) having a gripping groove (5515, 5525) formed with a radius of curvature equal to the radius of curvature of the curved surface of the side surface of the changed cylindrical battery cell (100).

[0061] Additionally, the holder (550) may include a pair of first gripping fingers (551) facing each other with the cylindrical battery cell (100) in between, and a pair of second gripping fingers (552) spaced apart from the pair of first gripping fingers (551) in a first direction and facing each other with the cylindrical battery cell in between. Accordingly, the holder (550) can support the side surface of the cylindrical battery cell (100) at four locations.

[0062] As described above, since the holder (550) supports the side surface of the cylindrical battery cell (100) at four points with a pair of first gripping fingers (551) and a pair of second gripping fingers (552) having gripping grooves (5515, 5525), it is possible to prevent the cylindrical battery cell (100) from moving while clamped to the holder (550), and to suppress deviations in the welding angle and welding position of the cylindrical battery cell (100) during welding as much as possible.

[0063] The first direction transfer unit (510) is configured to move the holder (550) in a first direction connecting the two bottom surfaces of the cylindrical battery cell (100). In FIG. 2, the arrow indicates the first direction. That is, the first direction transfer unit (510) transfers the holder (550) in the first direction so that at least one bottom surface of the cylindrical battery cell (100) comes into close contact with one or more welding masks (400).

[0064] For example, when welding both bottom surfaces of a cylindrical battery cell (100), two welding masks (400) may be arranged to each contact both bottom surfaces of the cylindrical battery cell (100). Then, the first direction transfer unit (510) can move the holder (550) holding the cylindrical battery cell (100) in a direction toward the welding mask (400) that contacts the bottom surface of the cylindrical battery cell (100) where welding is performed. That is, the first direction transfer unit (510) can move the holder (550) so that the bottom surface of the cylindrical battery cell (100) is in close contact with the welding mask (400), thereby pressing the welding mask (400) against the cylindrical battery cell (100).

[0065] For example, the first direction transfer unit (510) of the battery cell gripper (501) may include one of a linear motor or a ball screw motor. However, one embodiment of the present invention is not limited thereto, and the first direction transfer unit (510) may be made of various devices known to those skilled in the art to which the present invention belongs, as long as it is configured to move the holder (550) in a linear reciprocating motion in the first direction.

[0066] In one embodiment of the present invention according to the configuration described above, the jig device (101) can bring one side bottom surface of the cylindrical battery cell (100) into close contact with the welding mask (400) through the first direction transfer unit (510) included in the battery cell gripper (501) without the need to provide a separate pressing device for pressing the welding mask (400) against the bottom surface of the cylindrical battery cell (100).

[0067] The second direction transfer unit (520) can adjust the spacing between at least one pair of gripping fingers (551, 552) with the cylindrical battery cell (100) in between. For example, as shown in FIG. 3, when the at least one pair of gripping fingers (551, 552) release the clamping of the cylindrical battery cell (100) after the welding process is completed, the second direction transfer unit (520) can widen the spacing between the at least one pair of gripping fingers (551, 552). And as shown in FIG. 4, in order to grip the cylindrical battery cell (100) to be welded again, the second direction transfer unit (520) can transfer the at least one pair of gripping fingers (551, 552) in the second direction. In FIG. 3 and FIG. 4, the arrow indicates the second direction.

[0068] For example, the second direction transfer unit (520) of the battery cell gripper (501) may include one of a linear motor or a ball screw motor. However, one embodiment of the present invention is not limited thereto, and the second direction transfer unit (520) may be made of various devices known to those skilled in the art to which the present invention belongs, provided that it is configured to move the gripping fingers (551, 552) in a linear reciprocating motion in the second direction to adjust the spacing of at least one pair of gripping fingers (551, 552).

[0069] Additionally, as described above, a guide rail (not shown) may be formed on the base (200) to assist in the movement of the second direction transfer unit (520), and the second direction transfer unit (520) may move in the second direction along the guide rail formed on the base (200).

[0070]

[0071] According to one embodiment of the present invention, by such a configuration, a cylindrical battery cell (100) can be stably clamped when welding the electrode assembly (10) and the current collection plate (40).

[0072] Specifically, the cylindrical battery cell (100) can be clamped by at least one pair of gripping fingers (551, 552) with a portion of the side surface of the cylindrical battery cell (100) being received in the gripping grooves (5515, 5525) of the gripping fingers (551, 552). That is, the at least one pair of gripping fingers (551, 552) can grip the cylindrical battery cell (100) having a curved surface more stably, thereby effectively preventing movement of the cylindrical battery cell (100) during welding.

[0073] In addition, since the holder (550) of the battery cell gripper (501) supports the side surface of the cylindrical battery cell (100) at four points with a pair of first gripping fingers (551) and a pair of second gripping fingers (552), each having a gripping groove (5515, 5525), it is possible to prevent the cylindrical battery cell (100) from moving while clamped to the holder (550), and to suppress deviations in the welding angle and welding position of the cylindrical battery cell (100) during welding as much as possible.

[0074] Additionally, the jig device (101) can bring the bottom surface of the cylindrical battery cell (100) into close contact with the welding mask (400) through the first direction transfer unit (510) included in the battery cell gripper (501) without the need to provide a separate pressing device for pressing the welding mask (400) against the bottom surface of the cylindrical battery cell (100).

[0075]

[0076] Although the actions are depicted in a specific order in the drawings, it should not be understood that the actions must be executed in the specific order depicted or in sequential order, or that all depicted actions must be executed to obtain the desired result.

[0077] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment.

[0078] < Explanation of Symbols >

[0079] 10: Electrode assembly

[0080] 40: Current collection plate

[0081] 50: Battery case

[0082] 54: Bidding Department

[0083] 100: Cylindrical battery cell

[0084] 101: Jig device

[0085] 200: Bass

[0086] 400: Welding mask

[0087] 501: Battery Cell Gripper

[0088] 510: First direction transfer unit

[0089] 520: Second direction transfer unit

[0090] 550: Holder

[0091] 551: 1st Gripping Finger

[0092] 552: The Second Griping Finger

[0093] 5515, 5525: Waste paper groove

[0094] The present invention can be used to provide a battery cell gripper for stably clamping a cylindrical battery cell during welding of an electrode assembly and a current collector plate.

Claims

1. A battery cell gripper for gripping a cylindrical battery cell, A holder for clamping the side of a cylindrical battery cell; and A first direction transfer unit that moves the above holder in a first direction connecting the bottom surfaces of both sides of a cylindrical battery cell. A battery cell gripper including 2. In Paragraph 1, A battery cell gripper characterized in that the first direction transfer unit comprises one of a linear motor or a ball screw motor.

3. In Paragraph 1, A battery cell gripper characterized by the holder comprising at least one pair of gripping fingers facing each other with a cylindrical battery cell in between.

4. In Paragraph 3, A battery cell gripper characterized by having a curved gripping groove formed in the area where the above-mentioned pair of gripping fingers contact a cylindrical battery cell.

5. In Paragraph 4, A battery cell gripper characterized in that the above-mentioned gripping groove is formed in a shape corresponding to the curved surface of the side surface of a cylindrical battery cell.

6. In Paragraph 3, A battery cell gripper characterized by further including a second direction transfer unit for adjusting the spacing between the above-mentioned pair of gripping fingers.

7. In Paragraph 6, A battery cell gripper characterized in that the second direction transfer unit comprises one of a linear motor or a ball screw motor.

8. In Paragraph 1, The above holder is, A pair of first gripping fingers facing each other with a cylindrical battery cell in between; A pair of second gripping fingers spaced apart in the first direction from the pair of first gripping fingers and facing each other with a cylindrical battery cell in between. A battery cell gripper characterized by including 9. A jig device for clamping a cylindrical battery cell during welding of an electrode assembly and a contact plate, base; A battery cell gripper provided on the above base and clamping the side of a cylindrical battery cell; and One or more welding masks provided on the base and in contact with at least one bottom surface of the cylindrical battery cell Includes, The battery cell gripper mentioned above is, A holder for clamping the side of a cylindrical battery cell; and A first direction transfer unit that transfers the holder in a first direction so that at least one bottom surface of the cylindrical battery cell is in close contact with the one or more welding masks. A jig device characterized by including 10. In Paragraph 9, A jig device characterized in that the first direction transfer section of the battery cell gripper comprises one of a linear motor or a ball screw motor.

11. In Paragraph 9, A jig device characterized in that the holder of the battery cell gripper comprises at least one pair of gripping fingers facing each other with a cylindrical battery cell in between.

12. In Paragraph 11, A jig device characterized by having a curved gripping groove formed in the area where the above-mentioned pair of gripping fingers contact a cylindrical battery cell.

13. In Paragraph 12, A jig device characterized in that the above-mentioned gripping groove is formed in a shape corresponding to the curved surface of the side surface of a cylindrical battery cell.

14. In Paragraph 11, A jig device characterized by further including a second direction transfer unit that adjusts the spacing between the pair of gripping fingers in the battery cell gripper.

15. In Paragraph 14, A jig device characterized in that the second direction transfer section of the battery cell gripper comprises one of a linear motor or a ball screw motor.

16. In Paragraph 9, The holder of the battery cell gripper above is, A pair of first gripping fingers facing each other with a cylindrical battery cell in between; A pair of second gripping fingers spaced apart in the first direction from the pair of first gripping fingers and facing each other with a cylindrical battery cell in between. A jig device characterized by including

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