Electrode stacking apparatus

Abstract

The present application provides a structure of an electrode stack apparatus having a tension compensator which applies a compensating tension to a central portion of a separator to prevent the central portion and both end portions of the separator from being unevenly stretched and deformed in a zigzag stacking process.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0061913, filed on May 10, 2024, the entire contents of which are included in the document as part of this specification.

[0002] The present invention relates to the structure of an electrode stacking apparatus for a sawtooth stacking method for manufacturing electrode assemblies embedded in secondary battery cells. Background Technology

[0003] The product group offers rechargeable batteries that are easy to use and possess electrical characteristics such as high energy density. These batteries are widely used not only in portable devices but also in electric or hybrid vehicles powered by electric sources, as well as in energy storage devices. These rechargeable batteries are gaining attention as a new energy source for improving eco-friendliness and energy efficiency, not only because they have the key advantage of significantly reducing fossil fuel use, but also because they do not produce any byproducts from energy consumption.

[0004] While small mobile devices use one, two, or three battery cells per unit, medium to large devices such as vehicles require high output and large capacity. Therefore, medium to large battery modules or battery packs with multiple battery cells electrically connected are used.

[0005] Meanwhile, cylindrical, prismatic, and pouch-shaped battery cells are known as single-cell rechargeable batteries. Due to the desire to manufacture medium to large-sized battery modules that are as small and lightweight as possible, prismatic and pouch-shaped batteries, which are highly integrated and have a low weight per capacity, are primarily used as battery cells for medium to large-sized battery modules.

[0006] Among them, pouch cell batteries have various structures depending on the method of manufacturing the electrode assemblies housed within them. In particular, recently, high-capacity electrode assemblies of the stacked cell type are typically manufactured at high speed using a zigzag stacking method, which alternately stacks negative and positive electrodes between each layer of a separator folded in a zigzag pattern.

[0007] Figures 1 to 6 The stacking process of the diaphragm and electrodes via a zigzag stack is illustrated. (Refer to...) Figures 1 to 6The zigzag stacking is performed by alternately stacking a first electrode 11 and a second electrode 12 with different polarities using a zigzag folded diaphragm 13. Here, the diaphragm 13 is continuously supplied from the pinch roller 3 to the stacking platform 2, which reciprocates between a first relative position and a second relative position and folds around a first mandrel 21 and a second mandrel 22. The first mandrel 21 and the second mandrel 22 alternately clamp the diaphragm 13 while moving together with the stacking platform 2, thereby forming folds 133 and 134.

[0008] Figure 7 The diaphragm under tensile deformation is shown. (See reference...) Figure 7 The first mandrel 21 and the second mandrel 22 are configured as a pair, spaced apart from each other by a predetermined distance D along the width direction of the diaphragm 13. Therefore, when the stacking platform 2 shifts from a first relative position to a second relative position, tension is applied between the portion held by the second mandrel 22 and the pinch roller 3. Here, in the diaphragm 13, the portion held by the second mandrel 22 mainly undergoes tensile deformation, while the portion located between the pair of second mandrels 22 is almost undeformed, except for the portion closer to the second mandrel 22 which undergoes slight deformation due to friction with the second mandrel 22.

[0009] Uneven stretching deformation of the diaphragm 13 leads to protrusions or excessive dimensions in the finished electrode assembly, resulting in structural and functional defects. Therefore, there is an urgent need for technical means to solve this problem. Summary of the Invention

[0010] Technical issues

[0011] In order to solve the above-mentioned problems of the prior art, the object of the present invention is to provide a structure of an electrode stacking device that prevents uneven stretching deformation of the diaphragm in an electrode stacking device that manufactures electrode assemblies by serrated stacking.

[0012] Specifically, the purpose of this invention is to prevent non-uniform tensile deformation caused by the tension applied non-uniformly to the diaphragm by the mandrel that holds the diaphragm for folding.

[0013] Another object of the present invention is to provide a structure for an electrode stacking device that can manufacture electrode assemblies without defects such as bulges or excessive size caused by diaphragm deformation.

[0014] The technical problem to be solved by the present invention is not limited to the above-described objectives, and other objectives and advantages of the invention not described herein may be understood through the following description and will be more clearly understood through examples of the invention. Furthermore, it will be apparent that the objectives and advantages of the invention can be embodied by the means and combinations thereof indicated in the claims.

[0015] Technical solution

[0016] To address the aforementioned problems, the present invention provides a structure for an electrode stacking device, comprising: a stacking platform having a first electrode and a second electrode alternately stacked with a diaphragm having a predetermined width, wherein the diaphragm can be continuously arranged in a front-back direction and folded in a zigzag pattern, such that the first surface and the second surface of the diaphragm can be alternately exposed; a pair of pinch rollers symmetrically arranged on the left and right sides of a predetermined plane of symmetry, wherein the pair of pinch rollers can be perpendicularly spaced from the stacking platform to adjust the supply position of the diaphragm supplied to the stacking platform; and a driving unit that positions the stacking platform relative to the pair of pinch rollers within the plane of symmetry. The first relative position on the left side is shifted between a first relative position on the right side of the plane of symmetry; a pair of first mandrels spaced apart from each other by a predetermined distance in the front-rear direction and defining a right fold of the diaphragm, wherein the pair of first mandrels press a first surface of the diaphragm against the stacking platform at least when the stacking platform can be shifted from the first relative position to the second relative position; a pair of second mandrels spaced apart from each other by a predetermined distance in the front-rear direction and defining a left fold of the diaphragm, wherein the pair of second mandrels press a second surface of the diaphragm against the stacking platform at least when the stacking platform can be shifted from the second relative position to the first relative position; and a tension compensator that presses the surface of the diaphragm at least temporarily.

[0017] The tension compensator according to the invention is configured to apply compensating tension to the transverse central portion of the diaphragm so as to prevent uneven tensile deformation of the transverse central portion and the two transverse ends when the diaphragm is clamped at its transverse ends by the first mandrel and the second mandrel.

[0018] According to an embodiment, the tension compensator may include a first tension compensator and a second tension compensator arranged symmetrically with respect to a plane of symmetry. The first tension compensator and the second tension compensator may have a fixed relative position to the pinch roller.

[0019] The first tension compensator may be positioned on the left side relative to the plane of symmetry to press the diaphragm in at least a portion of the section where the stacking platform shifts from the second relative position to the first relative position. Here, the surface pressed by the first tension compensator may be the first surface of the diaphragm.

[0020] The second tension compensator may be disposed on the right side relative to the plane of symmetry to press the second surface of the diaphragm in at least a portion of the section where the stacking platform is shifted from the first relative position to the second relative position. Here, the surface pressed by the second tension compensator may be the second surface of the diaphragm.

[0021] Here, the diaphragm may be bent relative to the pinch roll, the first tension compensator and the second mandrel at least immediately after the stacking platform is moved to the first relative position, and its extension direction may be bent relative to the pinch roll, the second tension compensator and the first mandrel at least immediately after the stacking platform is moved to the second relative position.

[0022] According to a variant, the tension compensator can be displaced in association with the stacking platform. That is, the tension compensator can have a fixed relative position with respect to the stacking platform.

[0023] In this configuration, the tension compensator can press the second surface of the diaphragm in at least a portion of the section where the stacking platform is shifted from the first relative position to the second relative position, and press the first surface of the diaphragm in at least a portion of the section where the stacking platform is shifted from the second relative position to the first relative position.

[0024] Here, the tension compensator can be retracted after the stacking stage is moved to the first relative position or the second relative position and before the first electrode or the second electrode is stacked, so as not to interfere with the diaphragm. Then the tension compensator can be positioned after the first electrode or the second electrode is stacked and before the stacking stage is moved to the second relative position or the first relative position, so as to interfere with the diaphragm.

[0025] Specifically, according to one aspect of the invention, the tension compensator may have an elongated shape having a predetermined length in the longitudinal direction, with its central portion protruding further toward the diaphragm relative to the longitudinal direction than its front and rear ends. That is, when the diaphragm approaches and contacts the tension compensator, the central portion of the tension compensator relative to the longitudinal direction may contact the diaphragm first before contacting its front and rear ends. Therefore, the tension compensator can apply a greater tension to the transverse central portion than to the two transverse ends of the diaphragm, and compensate for the uneven tension applied to the diaphragm by the first and second mandrels.

[0026] According to embodiments of the present invention, the tension compensator may comprise a roller shape having a concentric circular cross-section along the longitudinal direction. Preferably, the tension compensator is mounted to be rotatable along the diaphragm's travel direction. Here, the diameter of the tension compensator at its central portion relative to the longitudinal direction may be larger than its diameter at its front and rear ends. In this case, the tension compensator may not cause unnecessary friction with the diaphragm, and therefore may not cause excessive deformation or damage to the diaphragm. However, it is sufficient that the tension compensator extends along the longitudinal direction and protrudes toward the diaphragm at its central portion relative to the longitudinal direction compared to its front and rear ends; the tension compensator need not be rotatably mounted or have a roller shape.

[0027] According to an embodiment of the invention, the diameter of the tension compensator can increase from its front and rear ends toward its central portion relative to the front-rear direction. Since the diaphragm undergoes tensile deformation increasing from its transverse central portion toward its transverse ends due to the tension and friction provided by the first or second mandrel, the tension compensator can compensate for this deformation by having a corresponding shape.

[0028] Furthermore, preferably, the rate of increase in the diameter of the tension compensator decreases from its front and rear ends toward its central portion relative to the front-rear direction. Therefore, the actual tensile deformation applied to the diaphragm can be accurately compensated, and the contact area between the tension compensator and the diaphragm forms a smooth curve without peaks, thus preventing damage to the diaphragm.

[0029] According to another embodiment, the tension compensator may include a tapered portion whose diameter increases toward its center relative to the front-rear direction in some sections, regardless of whether the diameter increases or decreases along the entire section in the front-rear direction.

[0030] Furthermore, the predetermined length can be equal to or less than the predetermined width. That is, the tension compensator can contact only a portion of the central part of the diaphragm in the width direction, rather than the entire central part.

[0031] Specifically, the predetermined length can be equal to or less than the predetermined distance. In this case, the tension compensator may not apply tension to the portion tensioned by the first or second mandrel.

[0032] According to another aspect of the invention, the tension compensator may have an elongated shape having a predetermined first length equal to or less than a predetermined width in the front-rear direction. That is, the tension compensator may contact only a portion of the central portion of the diaphragm in the width direction, rather than the entire central portion. Therefore, the tension compensator can apply a greater tension to the transverse central portion than to the two transverse ends of the diaphragm, and can compensate for uneven tension applied to the diaphragm by the first and second mandrels.

[0033] According to another embodiment of the invention, the tension compensator may comprise a roller shape having a concentric circular cross-section along the front-to-back direction. Preferably, the tension compensator is mounted to be rotatable along the diaphragm's travel direction. Here, the diameter of the tension compensator at its central portion relative to the front-to-back direction may be larger than its diameters at its front and rear ends. In this case, the tension compensator may not cause unnecessary friction with the diaphragm, and therefore may not cause excessive deformation or damage to the diaphragm. However, it is sufficient that the first length is less than the width of the diaphragm, and the tension compensator need not be rotatably mounted or have a roller shape.

[0034] A tension compensator according to another embodiment of the invention may include: a pair of tapered portions whose diameter increases toward the central portion of the tension compensator relative to the front-rear direction; and a flat portion extending a predetermined second length and connected to the pair of tapered portions with a constant diameter. Therefore, pressure applied to the diaphragm by the tension compensator is prevented from concentrating at the ends of the tension compensator, thereby preventing excessive deformation or damage to the diaphragm.

[0035] Preferably, the second length is equal to or less than a predetermined distance. In this case, the flat portion applies tension to the portions of the diaphragm where no tension is applied to the first and second mandrels, and the tapered portion prevents overlap in the degree of deformation at the boundary between the tension compensator's tensioned portion and the tensioned portions of the first and second mandrels. Furthermore, due to the friction between the first and second mandrels, tensile deformation may occur in the width-direction interior portion of the diaphragm located in contact with the first mandrel; therefore, preferably, the second length is set to be sufficiently less than the predetermined distance.

[0036] According to another embodiment of the present invention, the first length may be greater than a predetermined distance and less than a predetermined width.

[0037] According to another embodiment, the first length can be equal to or less than a predetermined distance. In this case, the tension compensator may not apply tension to the portion tensioned by the first or second mandrel.

[0038] The present invention also provides a structure for an electrode stacking device, the device comprising: a stacking platform having a first electrode and a second electrode alternately stacked with a diaphragm having a predetermined width, wherein the diaphragm can be continuously arranged in a front-back direction and folded in a zigzag manner, such that a first surface and a second surface of the diaphragm can be alternately exposed; a pair of elongated pinch rollers having a predetermined length in the front-back direction, wherein the pair of pinch rollers can be symmetrically arranged on the left and right sides of a predetermined plane of symmetry, and can be perpendicularly spaced from the stacking platform to adjust the supply position of the diaphragm supplied to the stacking platform; and a driving unit that positions the stacking platform relative to the pair of pinch rollers at a first relative position on the left side of the plane of symmetry. The diaphragm is shifted between a second relative position on the right side of the plane of symmetry; a pair of first mandrels spaced apart from each other by a predetermined distance in the front-rear direction and defining a right fold of the diaphragm, wherein, at least when the stacking platform can be shifted from the first relative position to the second relative position, the pair of first mandrels press the first surface of the diaphragm against the stacking platform; a pair of second mandrels spaced apart from each other by a predetermined distance in the front-rear direction and defining a left fold of the diaphragm, wherein, at least when the stacking platform can be shifted from the second relative position to the first relative position, the pair of second mandrels press the second surface of the diaphragm against the stacking platform, wherein, the diameter of each pinch roller at the portion corresponding to the transverse central portion of the diaphragm is greater than the diameter at the portions corresponding to the two transverse ends of the diaphragm.

[0039] In other words, the tension compensator according to the invention may be included in the pinch roller, or may be the pinch roller itself. That is, according to the invention, not only when the tension compensator is provided as a separate component, but also when the shape or size of the pinch roller is changed, the effect of preventing uneven tensile deformation of the transverse central portion and two transverse ends of the diaphragm by applying compensating tension to the transverse central portion of the diaphragm can be achieved.

[0040] Here, the feature “the diameter of each pinch roller is larger at the portion corresponding to the transverse central portion of the diaphragm than at the portions corresponding to the two transverse ends of the diaphragm” also includes the case where the predetermined length is less than the predetermined width, such that the pinch roller does not have a portion corresponding to the two transverse ends of the diaphragm or its diameter is 0.

[0041] In this case, it will be apparent from the description herein that the shape of the tension compensator described above can be referenced when constituting the specific shape of the pinch roll.

[0042] Beneficial effects

[0043] The present invention can provide a structure for an electrode stacking device in which uniform tension can be applied along the width of the diaphragm.

[0044] According to an embodiment of the present invention, an electrode stacking device is provided, the electrode stacking device being provided with a tension compensator that applies compensating tension to the non-uniform tension applied to the diaphragm by the mandrel, so as to obtain uniform tensile deformation of the diaphragm.

[0045] Therefore, the electrode stacking apparatus according to the invention can manufacture electrode assemblies with minimized defects caused by diaphragm deformation, excessive size, or expansion.

[0046] Furthermore, the present invention may have various other effects, and their descriptions will be given in each embodiment, or descriptions of effects that can be readily inferred by those skilled in the art will be omitted. Attached Figure Description

[0047] Figures 1 to 6 The stacking process of the diaphragm and electrodes is shown in a serrated stack.

[0048] Figure 7 The diaphragm under stretching deformation is shown.

[0049] Figure 8 An electrode stacking device according to an embodiment of the present invention is shown.

[0050] Figure 9 The electrode stacking process according to an embodiment of the present invention is shown.

[0051] Figure 10 The electrode stacking process according to the first variant is shown.

[0052] Figure 11 The electrode stacking process according to the second variant is shown.

[0053] Figure 12 The shape of a tension compensator according to an embodiment of the present invention is shown.

[0054] Figure 13 The shape of a tension compensator according to another embodiment of the present invention is shown.

[0055] [Explanation of reference numerals in the attached figures]

[0056] 11: First electrode 12: Second electrode 13: Diaphragm 131: First surface 132: Second surface 133: Left fold 134: Right fold 2: Stacking platform 20: Drive unit 21: First spindle 22: Second spindle 3: Pinch roller 4: Conveying device 51: (First) tension compensator 510: Conical portion 511: Flat portion 52: Second tension compensator S: Symmetry plane W: Width D: Distance L: Length L1: First length L2: Second length D1: First diameter D2: Second diameter Detailed Implementation

[0057] The above-described objects, features, and advantages will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to implement the technical concept of the present invention. In describing the present invention, detailed descriptions of prior art related to the present invention will be omitted where it is determined that such detailed descriptions unnecessarily obscure the spirit of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar parts.

[0058] Although terms such as "first" and "second" are used to describe various elements, these elements are certainly not limited by these terms. These terms are only used to distinguish one element from another, and unless otherwise specified, the first element may also be the second element.

[0059] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0060] In the following text, “arranging a component above (or below) a component” or “arranging a component at the top (or bottom) of a component” means not only “arranging a component in contact with the upper (or lower) surface”, but also “arranging a component above the upper (or lower) surface with another component inserted therebetween”.

[0061] Additionally, when an element is described as being “connected to” another element, “connected to” another element, or “in contact with” another element, it should be understood that the element may be “directly connected to” another element, “directly connected to” another element, or “directly in contact with” another element, or the element may be “connected to” another element, “connected to” another element, or “in contact with” another element with another element inserted therein or via another element.

[0062] Unless the context clearly specifies otherwise, the singular forms used herein include the plural forms. Terms such as “consisting of” or “comprising” as used herein should not be construed as including all elements or steps described in the specification, and should be construed as excluding some elements or steps, or including additional elements or steps.

[0063] Throughout this specification, unless otherwise specified, “A and / or B” means A, B, or A and B, and unless otherwise specified, “C to D” means from equal to or greater than C to equal to or less than D.

[0064] Although this article uses expressions related to direction such as vertical, left-right, and front-back for ease of description, these are not absolute directions related to the direction of gravity or any geographical orientation. For example, the vertical, left-right, and front-back directions used in this article can be understood as any of the three directions that intersect with the other two directions.

[0065] Preferred embodiments of the invention will be described below with reference to the accompanying drawings.

[0066] [Conventional zigzag stacking process]

[0067] Figures 1 to 6 The stacking process of the diaphragm and electrodes in a zigzag pattern is illustrated. Specifically, Figures 1 to 6 The electrode stacking apparatus for the first through sixth steps of the zigzag stacking process, which are repeatedly performed, is shown respectively. (Refer to...) Figures 1 to 6 The electrode stacking equipment includes: a stacking platform 2; a drive unit 20; a first mandrel 21; a second mandrel 22; a pinch roller 3; and a conveying device 4.

[0068] On the stacking platform 2, the first electrode 11 and the second electrode 12 are stacked alternately, with the diaphragm 13 inserted between them.

[0069] The pinch rollers 3 and the stacking platform 2 are arranged vertically and spaced apart from each other.

[0070] like Figure 1As shown, the pinch rollers 3 are a pair of rotatable roller-shaped members symmetrically arranged on the left and right sides of the virtual symmetry plane S, and the diaphragm 13 travels between the pair of pinch rollers 3 and is continuously supplied from a predetermined supply position adjusted by the pinch rollers 3. Here, the diaphragm 13 has a sheet shape extending with a predetermined width W, and is unwound from the diaphragm rollers and supplied.

[0071] The stacking stage 2 is driven by the drive unit 20 to reciprocate between a predetermined first relative position and a second relative position relative to the plane of symmetry S. Specifically, the drive unit 20 causes the stacking stage 2 to rotate about a central axis that is perpendicularly spaced from the stacking stage 2, and to reciprocate between the first relative position and the second relative position that are spaced apart in the circumferential direction of rotation at a predetermined period.

[0072] The first spindle 21 and the second spindle 22 are mounted to reciprocate relative to the central axis along with the stacking platform 2. The first spindle 21 and the second spindle 22 are arranged to be spaced apart from each other in the left-right direction relative to the stacking platform 2. The first spindle 21 and the second spindle 22 are configured as a pair that are separated by a predetermined distance in the front-back direction.

[0073] The first spindle 21 presses the first surface 131 of the diaphragm 13 against the stacking platform 2 at least when the stacking platform 2 is moved from the first relative position to the second relative position, and defines the right fold 134 of the diaphragm 13.

[0074] Specifically, refer to Figures 1 to 4 In the first step, the first mandrel 21 releases the pressure pressed against the diaphragm 13, and in the second step, it presses the first surface 131 of the diaphragm 13 against the stacking platform 2 again. In the third step, the conveying device 4 conveys and stacks the first electrode 11 onto the first surface 131 of the diaphragm 13. In the fourth step, the stacking platform 2 is moved to a second relative position, causing the diaphragm 13 to fold around the first mandrel 21 to form a right fold 134.

[0075] Similarly, at least when the stacking platform 2 shifts from the second relative position to the first relative position, the second mandrel 22 presses the second surface 132 of the diaphragm 13 against the stacking platform 2 and defines the left fold 133 of the diaphragm 13.

[0076] Specifically, refer to Figures 4 to 6 and Figure 1 In the fourth step, the second mandrel 22 releases the pressure on the diaphragm 13, and in the fifth step, it presses the first surface 131 of the diaphragm 13 against the stacking platform 2. In the sixth step, the conveying device 4 conveys and stacks the second electrode 12 onto the second surface 132 of the diaphragm 13. In the first step, the stacking platform 2 is moved to a first relative position, causing the diaphragm 13 to fold around the second mandrel 22 to form a left fold 133.

[0077] When steps one through six are repeated several times, an electrode assembly with a structure in which the first electrode 11 and the second electrode 12 are alternately laminated by each layer of a diaphragm 13 folded in a serrated pattern.

[0078] Here, a predetermined tension is continuously applied to the diaphragm 13 to achieve a precise supply speed and smooth operation of the diaphragm 13.

[0079] Figure 7 The diaphragm under tensile deformation is shown. (See reference...) Figure 7 In the first step, when the diaphragm 13 is folded by the pressure applied to it by the second mandrel 22, the second mandrel 22 provides a reaction force against the tension applied to the diaphragm 13. Here, specific portions of the two lateral ends of the diaphragm 13 that contact the second mandrel 22 receive greater tension than their lateral center portion, causing uneven tensile deformation in the diaphragm 13. Therefore, the right folded portion 134 undergoes deformation with its lateral center portion drooping inward, and due to the frictional force applied by the second mandrel 22, the portion adjacent to the inner end of the second mandrel 22 undergoes slight tensile deformation in the width direction of the diaphragm 13.

[0080] This phenomenon can occur not only in the same way as with the second mandrel 22, but also in the same way as with the first mandrel 21. That is, in the fourth step, because the first mandrel 21 presses down on the diaphragm 13 and provides a reaction force against the tension, uneven tensile deformation may occur in the left fold 133.

[0081] The features of the present invention described below are intended to solve such problems. However, the present invention is not necessarily limited to performing the above-described processes using an electrode assembly device having the above-described structure.

[0082] [Arrangement of tension compensators]

[0083] An electrode stacking device according to an embodiment of the present invention includes a reference. Figures 1 to 6 The described electrode stacking device is structured and used to manufacture electrode assemblies by repeatedly performing steps similar to the first to sixth steps, respectively. The electrode assembly device according to an embodiment of the invention is characterized by further including a tension compensator as described below. However, it should be understood that the invention also includes the application of the tension compensator described below to another type of electrode stacking device for serrated stacking.

[0084] In the following text, refer to Figures 8 to 11 The structure of the electrode stacking device according to the present invention, as well as the arrangement and operation of the tension compensator, are described.

[0085] Figure 8 An electrode stacking device according to an embodiment of the present invention is shown. (Refer to...) Figure 8 The electrode stacking device according to the invention includes a tension compensator 51, which presses the surface of the diaphragm 13 at least temporarily.

[0086] According to the tension compensator 51 of the present invention, compensating tension is applied to the transverse central portion of the diaphragm 13 in order to prevent the transverse central portion and the two transverse ends from undergoing uneven tensile deformation when the diaphragm 13 is clamped at its transverse ends by the first mandrel 21 and the second mandrel 22.

[0087] Figure 9 The electrode stacking process according to an embodiment of the present invention is illustrated. See also Figure 9 According to an embodiment of the present invention, the tension compensator 51 may include a first tension compensator 51 and a second tension compensator 52 arranged symmetrically with respect to the plane of symmetry S. The first tension compensator 51 and the second tension compensator 52 may have a fixed relative position with respect to the pinch roller 3.

[0088] The first tension compensator 51 is positioned on the left side relative to the plane of symmetry S to press the diaphragm 13 in at least a portion of the section where the stacking platform 2 is shifted from the second relative position to the first relative position. Specifically, the first tension compensator 51 may press the diaphragm 13 during the sixth step S6, the first step S1, and the second step S2. However, the first tension compensator 51 may be arranged to press the diaphragm 13 only in the first step S1. In this case, the surface pressed by the first tension compensator 51 may be the first surface 131 of the diaphragm 13.

[0089] The second tension compensator 52 is positioned on the right side relative to the plane of symmetry S to press the diaphragm 13 in at least a portion of the section where the stack platform 2 is shifted from the first relative position to the second relative position. Specifically, the second tension compensator 52 may press the diaphragm 13 during the third step S3 to the fifth step S5. However, the second tension compensator 52 may be arranged to press the diaphragm 13 only in the fourth step S4. In this case, the surface pressed by the second tension compensator 52 may be the second surface 132 of the diaphragm 13.

[0090] Here, the diaphragm 13 can be bent in its extension direction relative to the pinch roller 3, the first tension compensator 51 and the second mandrel 22 at least in the first step S1, and can be bent in its extension direction relative to the pinch roller 3, the second tension compensator 52 and the first mandrel 21 at least in the fourth step S4.

[0091] Figure 10 The electrode stacking process according to the first variant is shown. (Refer to...) Figure 10According to the first variant, the tension compensator 51 can be displaced in association with the stacking platform 2. That is, the tension compensator 51 can have a fixed relative position with respect to the stacking platform 2.

[0092] In this configuration, the tension compensator 51 can press the second surface 132 of the diaphragm 13 in at least some sections where the stacking platform 2 shifts from the second relative position to the first relative position, and can also press the first surface 131 of the diaphragm 13 in at least some sections where the stacking platform 2 shifts from the first relative position to the second relative position. Specifically, the tension compensator 51 can press the diaphragm 13 in each of the first step S1 and the fourth step S4.

[0093] Here, the tension compensator 51 can retract after the stacking platform 2 is moved to the first relative position or the second relative position, and before the first electrode 11 or the second electrode 12 is stacked (i.e., between the second step S2 and the fifth step S5, after the first electrode 11 or the second electrode 12 is stacked and before the stacking platform 2 is moved to the second relative position or the first relative position) so as not to interfere with the diaphragm 13. That is, the tension compensator 51 can be positioned to interfere with the diaphragm 13 again between the second step S2 and the fourth step S4 and between the fifth step S5 and the first step S1.

[0094] Figure 11 The electrode stacking process according to the second variation is shown. (Refer to...) Figure 11 According to the second variation, the tension compensator may be included in the pinch roller 3, or it may be the pinch roller 3 itself. That is, according to the embodiments of the present invention, not only when the tension compensator is provided separately, but also when the shape or size of the pinch roller 3 is changed, the effect of preventing uneven tensile deformation of the transverse central portion and the two transverse ends of the diaphragm 13 can be obtained by applying compensating tension to the transverse central portion of the diaphragm 13.

[0095] Specifically, in a pair of pinch rollers 3, the left pinch roller can apply pressure to the diaphragm 13 during the sixth step S6, the first step S1, and the second step S2. Here, the surface pressed by the first tension compensator 51 can be the first surface 131 of the diaphragm 13.

[0096] Similarly, in a pair of pinch rollers 3, the right pinch roller can apply pressure to the diaphragm 13 during the third step S3 to the fifth step S5. Here, the surface applied by the second tension compensator 52 can be the second surface 132 of the diaphragm 13.

[0097] [Shape of the tension compensator]

[0098] The tension compensator according to the invention may have a size or shape suitable for applying tension to a diaphragm to compensate for the tension applied by a first mandrel and a second mandrel. Although the following... Figure 12 and Figure 13 All examples show the first tension compensator placed in the first step; however, solutions to problems related to the shape and size of the tension compensator described below can be applied independently of the arrangement of the tension compensator described above, i.e., applied to all the above-described embodiments, first variants, and second variants of the invention. In the following, reference is made to... Figure 12 and Figure 13 The shape of the tension compensator according to the present invention will be described.

[0099] Figure 12 The shape of a tension compensator according to an embodiment of the present invention is shown. (Refer to...) Figure 12 According to an embodiment of the invention, the tension compensator 51 may have an elongated shape with a predetermined length l in the front-rear direction, and the tension compensator protrudes further toward the diaphragm 13 relative to its central portion in the front-rear direction than its front and rear ends. That is, when the diaphragm 13 approaches and contacts the tension compensator 51, the tension compensator 51 may first contact the diaphragm 13 relative to its central portion in the front-rear direction before contacting its front and rear ends. Therefore, the tension compensator 51 may apply a greater tension to the transverse central portion than to the two transverse ends of the diaphragm 13, and compensate for the uneven tension applied to the diaphragm 13 by the first mandrel 21 and the second mandrel 22.

[0100] According to an embodiment of the invention, the tension compensator 51 may comprise a roller shape having a concentric circular cross-section along the longitudinal direction. Preferably, the tension compensator 51 is mounted so as to be rotatable along the travel direction of the diaphragm 13. Here, the first diameter D1 at the front and rear ends of the tension compensator 51 may be smaller than the second diameter D2 at the central portion relative to the longitudinal direction. In this case, the tension compensator 51 may not cause unnecessary friction with the diaphragm 13, and therefore may not cause excessive deformation or damage to the diaphragm 13. However, it is sufficient that the tension compensator 51 extends along the longitudinal direction and protrudes towards the diaphragm 13 relative to the central portion of the longitudinal direction compared to its front and rear ends, and the tension compensator 51 need not be rotatably mounted or have a roller shape.

[0101] According to an embodiment of the invention, the diameter of the tension compensator 51 can increase from its front end and rear end toward its central portion relative to the front-rear direction. Since the diaphragm 13 is subjected to tensile deformation increasing from its transverse central portion toward its transverse end due to the tension and friction provided by the first spindle 21 or the second spindle 22, the tension compensator 51 can compensate for this deformation by having a corresponding shape.

[0102] Furthermore, preferably, the rate of increase in the diameter of the tension compensator 51 decreases from its front and rear ends toward its central portion relative to the front-rear direction. Therefore, the actual tensile deformation applied to the diaphragm 13 can be accurately compensated, and the contact area between the tension compensator 51 and the diaphragm 13 forms a smooth curve without peaks, thus preventing damage to the diaphragm 13.

[0103] Figure 13 The shape of a tension compensator according to another embodiment of the present invention is shown. (Refer to...) Figure 13 The tension compensator 51 may have an elongated shape with a predetermined first length L1 equal to or less than a predetermined width W in the front-to-back direction. That is, the tension compensator 51 may contact only a portion of the central portion of the diaphragm 13 in the width direction, rather than the entire central portion. Therefore, the tension compensator 51 may apply a greater tension to the transverse central portion of the diaphragm 13 than to the two transverse ends, and may compensate for the uneven tension applied to the diaphragm 13 by the first mandrel 21 and the second mandrel 22.

[0104] According to another embodiment of the invention, the tension compensator 51 may comprise a roller shape having a concentric circular cross-section along the front-rear direction. Preferably, the tension compensator 51 is mounted so as to be rotatable along the travel direction of the diaphragm 13. Here, the diameter of the tension compensator 51 at its central portion relative to the front-rear direction may be larger than the diameter at its front and rear ends. In this case, the tension compensator 51 may not cause unnecessary friction with the diaphragm 13, and therefore may not cause excessive deformation or damage to the diaphragm 13. However, it is sufficient that the first length L1 is less than the width W of the diaphragm 13, and the tension compensator 51 need not be rotatably mounted or have a roller shape.

[0105] According to another embodiment of the invention, the tension compensator 51 may include: a pair of tapered portions 510, the diameter of which increases toward the center of the tension compensator relative to the front-rear direction; and a flat portion 511 extending a predetermined second length L2 and connected to the pair of tapered portions 510 with a constant diameter. Therefore, the pressure applied to the diaphragm 13 by the tension compensator 51 is prevented from concentrating at the end of the tension compensator 51, thereby preventing excessive deformation or damage to the diaphragm 13.

[0106] Preferably, the second length L2 is equal to or less than the predetermined distance D. In this case, the flat portion 511 applies tension to the portions of the diaphragm 13 where no tension is applied to the first spindle 21 and the second spindle 22, and the tapered portion 510 can prevent overlap of the degree of deformation at the boundary between the portion of the tension compensator 51 where tension is applied and the portions of the first spindle 21 and the second spindle 22 where tension is applied. Furthermore, due to the friction between the first spindle 21 and the second spindle 22, tensile deformation may occur in the portion of the diaphragm 13 located within the width direction of the portion contacting the first spindle 21; therefore, preferably, the second length L2 is set to be sufficiently less than the predetermined distance D.

[0107] According to another embodiment of the present invention, the first length L1 may be greater than the predetermined distance D and less than the predetermined width W.

[0108] According to another embodiment of the invention, the first length L1 may be equal to or less than a predetermined distance D. In this case, the tension compensator 51 may not apply tension to the portion of the first spindle 21 or the second spindle 22 that is not under tension.

[0109] It should be understood that the described embodiments are illustrative in all respects and not restrictive, and the scope of the invention will be indicated by the appended claims rather than the detailed description described herein. Furthermore, the meaning and scope of the claims described below, as well as all changes and modifications derived from equivalent concepts, should be interpreted as being included within the scope of the invention.

[0110] Although the invention has been described with reference to exemplary accompanying drawings, it should be understood that the invention is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications are possible without departing from the scope and spirit of the invention. Furthermore, although the operational effects of configurations according to the invention are not explicitly described in the description of embodiments of the invention, it should be understood that predictable effects will also be recognized through configuration.

Claims

1. An electrode stacking device, the electrode stacking device comprising: A stacking platform having a first electrode and a second electrode, the first electrode and the second electrode being alternately stacked with a diaphragm having a predetermined width, wherein the diaphragm is continuously arranged in a front-back direction and folded in a zigzag manner, such that the first surface and the second surface of the diaphragm are alternately exposed; A pair of pinch rollers are arranged symmetrically on the left and right sides of a predetermined plane of symmetry, wherein the pair of pinch rollers are perpendicularly spaced from the stacking platform to adjust the supply position of the diaphragm supplied to the stacking platform. A drive unit that shifts the position of the stacking platform relative to the pair of pinch rollers between a first relative position on the left side of the plane of symmetry and a second relative position on the right side of the plane of symmetry; A pair of first mandrels, the pair of first mandrels being spaced apart from each other by a predetermined distance along the front-back direction and defining the right fold of the diaphragm, wherein the pair of first mandrels press the first surface of the diaphragm against the stacking platform at least when the stacking platform is moved from the first relative position to the second relative position; A pair of first mandrels, spaced apart from each other by a predetermined distance along the front-rear direction and defining a left fold of the diaphragm, wherein a pair of second mandrels press the second surface of the diaphragm against the stacking platform at least when the stacking platform shifts from the second relative position to the first relative position; and An elongated tension compensator having a predetermined length in the front-rear direction to at least temporarily press the surface of the diaphragm, the tension compensator having a central portion relative to the front-rear direction that protrudes further toward the diaphragm than the front and rear ends of the tension compensator.

2. The electrode stacking device according to claim 1, wherein, The tension compensator includes: A first tension compensator, disposed on the left side relative to the plane of symmetry, presses against the first surface of the diaphragm in at least a portion of the section where the stacking platform is shifted from the second relative position to the first relative position; and A second tension compensator is disposed on the right side relative to the plane of symmetry and presses the second surface of the diaphragm in at least a portion of the section in which the stacking platform is shifted from the first relative position to the second relative position.

3. The electrode stacking device according to claim 1, wherein, The tension compensator: is displaced in association with the stacking platform; presses the second surface of the diaphragm in at least a portion of the section of the stacking platform that is displaced from the first relative position to the second relative position; and presses the first surface of the diaphragm in at least a portion of the section of the stacking platform that is displaced from the second relative position to the first relative position.

4. The electrode stacking device according to claim 1, wherein, The tension compensator includes a roller shape having a concentric circular cross-section along the front-back direction, and The diameter of the tension compensator at its central portion relative to the front-rear direction is greater than the diameter at its front and rear ends.

5. The electrode stacking device according to claim 4, wherein, The diameter of the tension compensator increases from the front end and the rear end of the tension compensator toward the central portion of the tension compensator relative to the front-rear direction.

6. The electrode stacking device according to claim 5, wherein, The rate of increase of the diameter of the tension compensator decreases from the front end and the rear end of the tension compensator toward the central portion of the tension compensator relative to the front-rear direction.

7. The electrode stacking device according to claim 4, wherein, The tension compensator includes a tapered portion having a diameter that increases toward the central portion of the tension compensator relative to the front-rear direction.

8. The electrode stacking device according to claim 1, wherein, The predetermined length is equal to or less than the predetermined width.

9. The electrode stacking device according to claim 8, wherein, The predetermined length is equal to or less than the predetermined distance.

10. An electrode stacking device, the electrode stacking device comprising: A stacking platform having a first electrode and a second electrode, the first electrode and the second electrode being alternately stacked with a diaphragm having a predetermined width, wherein the diaphragm is continuously arranged in a front-back direction and folded in a zigzag manner, such that the first surface and the second surface of the diaphragm are alternately exposed; A pair of pinch rollers are arranged symmetrically on the left and right sides of a predetermined plane of symmetry, wherein the pair of pinch rollers are perpendicularly spaced from the stacking platform to adjust the supply position of the diaphragm supplied to the stacking platform. A drive unit that shifts the position of the stacking platform relative to the pair of pinch rollers between a first relative position on the left side of the plane of symmetry and a second relative position on the right side of the plane of symmetry; A pair of first mandrels, the pair of first mandrels being spaced apart from each other by a predetermined distance along the front-back direction and defining the right fold of the diaphragm, wherein the pair of first mandrels press the first surface of the diaphragm against the stacking platform at least when the stacking platform is moved from the first relative position to the second relative position; A pair of second mandrels, spaced apart from each other by a predetermined distance along the front-rear direction and defining a left fold of the diaphragm, wherein the pair of second mandrels press the second surface of the diaphragm against the stacking platform at least when the stacking platform shifts from the second relative position to the first relative position; and An elongated tension compensator having a predetermined first length along the front-back direction equal to or less than the predetermined width, so as to press the surface of the diaphragm at least temporarily.

11. The electrode stacking apparatus according to claim 10, wherein, The tension compensator includes: A first tension compensator, disposed on the left side relative to the plane of symmetry, presses against the first surface of the diaphragm in at least a portion of the section where the stacking platform is shifted from the second relative position to the first relative position; and A second tension compensator is disposed on the right side relative to the plane of symmetry and presses the second surface of the diaphragm in at least a portion of the section in which the stacking platform is shifted from the first relative position to the second relative position.

12. The electrode stacking apparatus according to claim 10, wherein, The tension compensator: is displaced in association with the stacking platform; presses the second surface of the diaphragm in at least a portion of the section of the stacking platform that is displaced from the first relative position to the second relative position; and presses the first surface of the diaphragm in at least a portion of the section of the stacking platform that is displaced from the second relative position to the first relative position.

13. The electrode stacking device according to claim 10, wherein, The tension compensator includes a roller shape having a circular cross-section along the front-rear direction, and The diameter of the tension compensator at its central portion relative to the front-rear direction is greater than the diameter at its front and rear ends.

14. The electrode stacking apparatus according to claim 13, wherein, The tension compensator includes: A pair of tapered portions, the diameter of which increases toward the center of the tension compensator relative to the front-rear direction; and A flat portion, which extends a predetermined second length and connects the pair of tapered portions with a constant diameter.

15. The electrode stacking apparatus according to claim 14, wherein, The second length is equal to or less than the predetermined distance.

16. The electrode stacking apparatus according to claim 10, wherein, The first length is equal to or less than the predetermined distance.

17. An electrode stacking apparatus, the electrode stacking apparatus comprising: A stacking platform having a first electrode and a second electrode, the first electrode and the second electrode being alternately stacked with a diaphragm having a predetermined width, wherein the diaphragm is continuously arranged in a front-back direction and folded in a zigzag manner, such that the first surface and the second surface of the diaphragm are alternately exposed; A pair of elongated pinch rollers having a predetermined length in the front-rear direction, wherein the pair of pinch rollers are symmetrically arranged on the left and right sides of a predetermined plane of symmetry and are perpendicularly spaced from the stacking platform to adjust the supply position of the diaphragm supplied to the stacking platform. A drive unit that shifts the position of the stacking platform relative to the pair of pinch rollers between a first relative position on the left side of the plane of symmetry and a second relative position on the right side of the plane of symmetry; A pair of first mandrels, spaced apart from each other by a predetermined distance along the front-rear direction and defining a right fold of the diaphragm, wherein the pair of first mandrels press the first surface of the diaphragm against the stacking platform at least when the stacking platform is moved from the first relative position to the second relative position; and A pair of second mandrels, spaced apart from each other by a predetermined distance along the front-rear direction and defining a left fold of the diaphragm, wherein the pair of second mandrels press the second surface of the diaphragm against the stacking platform at least when the stacking platform shifts from the second relative position to the first relative position. The diameter of each of the pinch rollers at the portion corresponding to the transverse central portion of the diaphragm is greater than the diameter at the portions corresponding to the two transverse ends of the diaphragm.

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