Electrode stacking device, electrode stacking method, and electrode assembly

Abstract

The present invention provides an electrode stacking device in which a pulling unit for pulling a separator is disposed on the opposite side of an anode magazine in the width direction with respect to a stack table. The present invention also provides an electrode stacking method comprising a folding step of folding the separator an odd number of times before starting a new stacking step after a step of cutting the separator. In addition, the present invention provides an electrode assembly having a multi-layer part in which a separator is folded as an even number of layers on the lower side of an anode constituting the lowermost layer.

Description

Electrode stacking device, electrode stacking method, and electrode assembly

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0040430 filed on March 28, 2025, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to an efficient electrode stacking device and an electrode stacking method. The present invention also provides a structure of an efficiently manufactured electrode assembly.

[0003] 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.

[0004] 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.

[0005] 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 individual secondary 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 and / or charge / discharge capacity.

[0006] Meanwhile, cylindrical, prismatic, and pouch-type battery cells are known as types of unit secondary battery cells.

[0007] 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.

[0008] 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.

[0009] 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 individual secondary 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 and / or charge / discharge capacity.

[0010] Meanwhile, cylindrical, prismatic, and pouch-type battery cells are known as types of unit secondary battery cells. In particular, pouch-type battery cells generally incorporate a stacked electrode assembly in which separators and electrodes are alternately stacked.

[0011] FIGS. 1 to 4 illustrate a general zigzag stacking process. Referring to these figures, zigzag stacking is performed by stacking a positive electrode (11) and a negative electrode (12) between each layer of a separator (10) that is continuously supplied and folded in a zigzag pattern. The separator (10) is supplied through a supply roller (31) of a stacking unit (3) and is folded by a swing roller (32) that reciprocates around the supply roller (31).

[0012] This process is performed on a stack table (2) until the electrodes (11, 12) and the separator (10) are stacked in a predetermined number of layers to complete the electrode stack, and is repeated to manufacture the next electrode stack after the electrode stack is discharged. At this time, the negative electrode (12) is stacked one more layer than the positive electrode (11), so the total number of electrodes (11, 12) is generally an odd number.

[0013] FIGS. 5 and 6 illustrate the process of pulling and cutting a completed electrode stack. Referring to these drawings, the completed electrode assembly (1) is pulled from the stack table (2) through the above process. At this time, the swing roller (32) maintains its position and unfolds the separator (10) between the electrode assembly (1). The unfolded separator (10) is cut at a predetermined point, and the excess portion on the side of the electrode assembly (1) finishes the electrode assembly (1) and forms the electrode assembly, while the first end of the cut separator (10) is fixed again to the stack table (2) to form the next electrode stack.

[0014] At this time, in order to maintain the appropriate tension of the separator (10) and fix the first end thereon at a predetermined position on the stack table (2) during the pulling of the electrode assembly (1) and the cutting of the separator (10), the swing roller (32) must maintain that position.

[0015] FIGS. 7 and 8 show the cathode pickup device picking up the first cathode. Referring to these figures, since the stacking unit (3) cannot move during the pulling and cutting process of the separator (10), in order to start a new stacking process thereafter, the only option is to wait for the pulling and cutting to be finished, and then have the stacking unit (3) swing back and forth so that the cathode pickup device (34) goes to pick up the first cathode (12). This causes a time gap between the discharge of the completed electrode assembly (1) and the new electrode stacking process, thereby causing process inefficiency.

[0016] The present invention was conceived against the background of the prior art described above and aims to provide an electrode stacking device with improved process efficiency. Specifically, the present invention aims to provide an electrode stacking device that drastically reduces the preparation time between each cycle of an electrode stacking device that repeatedly performs a cycle for manufacturing an electrode assembly.

[0017] The present invention also aims to provide an electrode stacking method for manufacturing an electrode assembly, wherein the preparation time between each cycle is significantly reduced.

[0018] The present invention also has as another technical objective the provision of a structure for an electrode assembly that can be manufactured in a time-efficient manner.

[0019] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0020] To solve the above problem, the present invention provides an electrode stacking device for stacking an anode and a cathode together with a separator to manufacture an electrode assembly.

[0021] The electrode stacking device according to the present invention may be used to perform the electrode stacking method according to the present invention described below, but the method of use is not limited thereto.

[0022] The electrode stacking device comprises: a stack table; an anode magazine disposed on the first width direction side of the stack table and loaded with anodes; a cathode magazine disposed on the second width direction side of the stack table and loaded with cathodes; a stacking unit for manufacturing an electrode assembly by stacking a separator that is folded in a zigzag pattern on the stack table and the anodes and cathodes interposed between each layer of the separator; and a pulling unit disposed on the first width direction side of the stack table and gripping the completed electrode assembly from the stack table and pulling it in the first width direction.

[0023] The electrode stacking device according to the present invention has the advantage of being time-efficient, as the pulling unit is positioned on the opposite side in the width direction of the cathode magazine relative to the stack table, so that while the separator is being pulled and cut, the stacking unit can pick up the cathode and simultaneously stack the first sheet of the cathode while the completed electrode assembly is being discharged.

[0024] Herein, the stacking unit comprises: a folding unit that folds the separator in a zigzag manner while moving back and forth relative between a first relative position set in the first width direction and a second relative position set in the second width direction with respect to the stack table; an anode pickup unit that picks up the anode from the anode magazine and stacks it on the separator; and a cathode pickup unit that picks up the cathode from the cathode magazine and stacks it on the separator.

[0025] The above electrode stacking device may be used to perform the electrode stacking method according to the present invention described below, but the method of use is not limited thereto.

[0026] According to one embodiment, the folding unit may include: a supply roller that continuously supplies the separator; and a swing roller that reciprocates and swings below the supply roller and folds the separator in a zigzag pattern on both sides in the width direction. However, the structure of the electrode stacking device is not limited thereto and may have various structures, such as a structure in which the folding unit moves relative to the stack table by reciprocating with respect to the fixed folding unit.

[0027] Meanwhile, according to the above embodiment, the positive pickup unit may be installed to swing together with the swing roller on the first width direction side of the swing roller, and the negative pickup unit may be installed to swing together with the swing roller on the second width direction side of the swing roller.

[0028] According to the above embodiment, the positive pickup unit may be installed to face the positive magazine when the folding unit is placed at the first relative position, and to face the stack table when the folding unit is placed at the second relative position.

[0029] Likewise, at this time, the cathode pickup unit may be installed to face the cathode magazine when the folding unit is placed at the second relative position, and to face the stack table when the folding unit is placed at the first relative position.

[0030] According to this structure, the operation of the folding unit folding the separator can be linked at the precise timing with the operation of the positive pickup unit and the negative pickup unit picking up the positive and the negative.

[0031] The stack table may additionally include a fixing unit configured to fix an end of the separator on the first width direction side of its upper surface. By fixing the separator to the stack table, the fixing unit maintains the alignment of the separator with respect to the anode and the cathode, and provides appropriate tension to enable the separator to unfold and fold between the folding unit and the stack table.

[0032] According to one embodiment, the fixing unit may be configured to adsorb and fix the separator. However, the fixing unit may have any shape or structure as long as it is capable of performing the operation of fixing and releasing the separator to the upper surface of the stack table.

[0033] The electrode stacking device may further include a cutting unit that cuts the separator between the stack table and the pulling unit. As the cutting unit cuts the separator, the finished electrode assembly can be separated from the folding unit and discharged.

[0034] According to one embodiment, the cutting unit may include a thermal cutter that melts and cuts the separator. However, the cutting unit may have any shape or structure as long as it is capable of performing the operation of cutting the separator.

[0035] The present invention also provides an electrode stacking method using the electrode stacking device.

[0036] The electrode stacking method according to the present invention is characterized by repeating a first cycle comprising a stacking unit stacking either the anode or the cathode on the stack table and a second step in which the stacking unit folds the separator once, thereby completing the electrode assembly on the stack table; a pulling unit pulling the electrode assembly in the first width direction while the folding unit is placed at the second relative position; and a folding unit folding the separator a predetermined odd number of times, wherein the second cycle is repeated.

[0037] In the electrode stacking device described above, the cathode magazine is positioned on the second width direction side and the pulling unit is positioned on the first width direction side relative to the stack table. Accordingly, when the completed electrode assembly is pulled in the first width direction, the folding unit is placed at the second relative position, and the cathode pickup unit is placed in a state where the cathode cannot be stacked immediately. The electrode stacking method according to the present invention solves this problem by including the folding step in which the separator is folded an odd number of times after the pulling step.

[0038] Specifically, the stacking step may be performed in the order that the cathode is stacked first, the anode and the cathode are alternately and repeatedly stacked, and finally the cathode is stacked. Accordingly, the total number of stacked anodes and cathodes is odd, and the first cycle is also performed an odd number of times.

[0039] At this time, according to one embodiment, in each second cycle, in the remaining first cycle excluding the last first cycle, the stacking unit can stack either the anode or the cathode while picking up the other.

[0040] The electrode stacking method may further include a cutting step between the pulling step and the folding step, in which the separator is cut between the stack table and the pulling unit. As the cutting step is performed, the completed electrode assembly can be separated from the folding unit and discharged.

[0041] The electrode stacking method according to one embodiment may further include a fixing step between the pulling step and the cutting step, wherein the separator is fixed to the first width direction side of the upper surface of the stack table. Specifically, the fixing step may be performed simultaneously with the cutting step. By fixing the separator to the stack table before the folding step begins, the alignment of the separator with respect to the anode and the cathode can be maintained, and appropriate tension can be provided between the folding unit and the stack table for the separator to unfold and fold.

[0042] According to one embodiment, the separator may be folded once in the folding step. However, the number of times the separator is folded in the folding step may be any number of times, provided that it is an odd number so that the stacking unit can be placed at the first relative position with the cathode pickup unit picking up the cathode just before the folding step ends and a new stacking step begins.

[0043] The present invention also provides a structure of an electrode assembly. The electrode assembly according to the present invention may be manufactured using the electrode stacking device and / or the electrode stacking method according to the present invention, but the means and method of manufacturing are not limited thereto.

[0044] The electrode assembly may include: a positive electrode; a negative electrode arranged alternately with the positive electrode along the stacking direction; and a separator folded in a zigzag and stacked together with the electrode. Each layer of the zigzag-folded separator is interposed between the positive electrode and the negative electrode, so that the positive electrode and the negative electrode can be used in a battery reaction while isolated from each other by the separator.

[0045] The electrode assembly according to the present invention is characterized in that the lowest and uppermost layers among the arrangement of the anode and the cathode are composed of the cathode, and the separator comprises a multilayer portion folded in an even number of layers on the lower side of the cathode constituting the lowest layer.

[0046] Here, the statement that the multilayer portion is folded into an even number of layers means that the multilayer portion is overlapped into an even number of layers along the stacking direction. For example, the multilayer portion may be folded once to form two layers, with two layers overlapping each other in the stacking direction and having one folding portion. Or, for example, the multilayer portion may be folded three times to form four layers, with four layers overlapping each other in the stacking direction and having three folding portions.

[0047] According to one embodiment, the multilayer portion may be formed in two layers for the energy density of the electrode assembly.

[0048] The separator may include a plurality of folding portions. Specifically, the folding portion refers to a portion having a shape that is substantially bent 180 degrees so that the separator has a leading edge facing the first width direction or the second width direction. The separator may form a zigzag shape by connecting the spaces between the folding portions that are alternately formed on the first width direction side and the second width direction side along the stacking direction.

[0049] At this time, the folding portion may include: a first folding portion surrounding the first width direction side of the cathode; a second folding portion surrounding the second width direction side of the anode; and an odd number of third folding portions constituting the multilayer portion.

[0050] However, the above folding portion may include other folding portions in addition to the first folding portion, the second folding portion, and the third folding portion. For example, the above folding portion may be formed on the upper side of the cathode constituting the uppermost layer, such that it does not surround either the anode or the cathode, nor does it constitute the multilayer portion.

[0051] At this time, the positive electrode and the negative electrode are arranged alternately, and as the negative electrode constitutes the uppermost and lowermost layers of the arrangement, the number of negative electrodes may be one more than the number of positive electrodes. Here, as the number of the first folding part and the second folding part are provided in a number corresponding to the number of positive electrodes and the number of negative electrodes, the number of the first folding part may be one more than the number of the second folding part.

[0052] Independently thereof, it is preferable that the third folding part be an even number. This means that even if the folding part includes other folding parts in addition to the first folding part, the second folding part, and the third folding part, it is preferable that the total number of folding parts be an even number.

[0053] The present invention can provide an electrode stacking device with improved process efficiency. Specifically, the present invention can provide an electrode stacking device that drastically reduces the preparation time between each cycle of an electrode stacking device that repeatedly performs a cycle for manufacturing an electrode assembly.

[0054] The present invention can also provide an electrode stacking method for manufacturing an electrode assembly, wherein the preparation time between each cycle is significantly reduced.

[0055] The present invention can also provide a structure of an electrode assembly that can be manufactured in a time-efficient manner.

[0056] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by a person skilled in the art, etc., will be omitted.

[0057] Figures 1 to 4 illustrate a general zigzag stacking process.

[0058] Figures 5 and 6 show the process of pulling and cutting the completed electrode laminate.

[0059] Figures 7 and 8 show the cathode pickup device picking up the first cathode.

[0060] FIG. 9 shows an electrode stacking device according to one embodiment.

[0061] FIG. 10 illustrates an electrode stacking method according to one embodiment.

[0062] FIGS. 11 to 13 show the first cycle of an electrode stacking method according to one embodiment being performed.

[0063] FIG. 14 shows the stacking step performed according to one embodiment.

[0064] FIG. 15 shows the pooling step performed according to one embodiment.

[0065] FIG. 16 shows the fixing step and cutting step performed according to one embodiment.

[0066] FIG. 17 shows the folding step performed according to one embodiment.

[0067] FIG. 18 shows an electrode assembly according to one embodiment, and FIG. 19 shows one cross-section thereof.

[0068] [Explanation of the symbol]

[0069] 1: Electrode assembly 10: Separator 11: Anode 12: Cathode 2: Stack table 20: Fixing unit 3: Stacking unit 31: Supply roller 32: Swing roller 33: Anode pickup unit 34: Cathode pickup unit 41: Anode magazine 42: Cathode magazine 5: Pulling unit 6: Cutting unit F1-F3: 1st-3rd folding sections

[0070] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0071] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0072] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0073] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0074] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0075] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0076] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0077] Throughout this specification, expressions related to the vertical direction and the width direction are used; however, the expression "vertical direction" (or "stacking direction") refers to any two opposing directions determined relatively, regardless of absolute orientations such as the direction of gravity, and the width direction, which includes the opposing first and second width directions, refers to any two directions that intersect the vertical direction (or stacking direction). For convenience of explanation, in the drawings included in this specification, the vertical direction is depicted as the vertical direction (vertical direction) and the width direction (first width direction and second width direction) is depicted as the horizontal direction (left-right direction); in particular, the first width direction is depicted as the right and the second width direction as the left. However, such depictions in the drawings are unrelated to any absolute reference orientation, and angles formed between the directions in the drawings (such as appearing to be orthogonal to each other) are merely for illustrative purposes and are irrelevant to the configuration of the present invention.

[0078] The present invention relates to an electrode stacking apparatus and an electrode stacking method for stacking electrodes together with a separator to manufacture an electrode assembly. The electrode stacking apparatus according to the present invention may be used in the electrode stacking method according to the present invention, but it may also be operated in a different manner.

[0079] The present invention also provides a structure of an electrode assembly. The electrode assembly according to the present invention may be manufactured using the electrode stacking device and / or the electrode stacking method according to the present invention, but the means and method of manufacturing are not limited thereto.

[0080] Meanwhile, for the sake of convenience of explanation, in one embodiment of the present invention described below, the case in which the electrode stacking device performs the electrode stacking method to manufacture the electrode assembly will be described.

[0081] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0082] FIG. 9 illustrates an electrode stacking device according to one embodiment. Referring thereto, the electrode stacking device comprises: a stack table (2); an anode magazine (41) disposed on the first width direction side of the stack table (2) and loaded with an anode (11); a cathode magazine (42) disposed on the second width direction side of the stack table (2) and loaded with a cathode (12); and a stacking unit (3) for manufacturing an electrode assembly (1) by stacking a separator (10) that is folded in a zigzag pattern on the stack table (2) and the anode (11) and the cathode (12) that are interposed between each layer of the separator (10).

[0083] The above electrode stacking device may be used to perform the electrode stacking method described below, but the method of use is not limited thereto.

[0084] The stacking unit (3) comprises: a folding unit (31, 32) that folds the separator (10) in a zigzag manner by moving back and forth between a first relative position set in the first width direction and a second relative position set in the second width direction relative to the stack table (2); an anode pickup unit (33) that picks up the anode (11) from the anode magazine (41) and stacks it on the separator (10); and a cathode pickup unit (34) that picks up the cathode (12) from the cathode magazine (42) and stacks it on the separator (10).

[0085] According to one embodiment, the folding unit (31, 32) may include: a supply roller (31) that continuously supplies the separator (10); and a swing roller (32) that reciprocates swinging below the supply roller (31) and folds the separator (10) in a zigzag pattern on both sides in the width direction. However, the structure of the electrode stacking device is not limited thereto and may have various structures, such as a structure in which the folding unit (31, 32) moves relative to the stack table (2) by reciprocating swinging with respect to the fixed folding unit (31, 32).

[0086] An electrode stacking method according to one embodiment is performed using the electrode stacking device.

[0087] FIG. 10 illustrates an electrode stacking method according to one embodiment. Hereinafter, the electrode stacking apparatus and the electrode stacking method according to one embodiment will be described in detail with reference to the drawings for each step.

[0088] FIGS. 11 to 13 show the first cycle of the electrode stacking method according to one embodiment being performed, and FIG. 14 shows the stacking step according to one embodiment being performed. Here, the folding unit (31, 32) of FIGS. 11 and 13 is positioned at the first relative position, and the folding unit (31, 32) of FIGS. 12 and 14 is positioned at the second relative position. Referring again to FIG. 10 in conjunction with these figures, the electrode stacking method includes a stacking step (S1) of stacking the anode (11) and the cathode (12) together with the separator (10) to complete the electrode assembly (1).

[0089] As shown in FIG. 10, the electrode stacking method according to the present embodiment is performed by repeating a first cycle (C1) a predetermined number of times. The first cycle (C1) may consist of a first step (S11) in which the stacking unit (3) stacks either the anode (11) or the cathode (12) on the stack table (2), and a second step (S12) in which the stacking unit folds the separator (10) once. By repeating this process, the anode (11) and the cathode (12) are stacked alternately, and the separator (10) may be interposed between each of the anode (11) and the cathode (12) by folding it in a zigzag pattern.

[0090] At this time, in each second cycle (C2), in the remaining first cycle (C1) excluding the last first cycle (C1), the stacking unit (3) can stack either the anode (11) or the cathode (12) while picking up the other.

[0091] According to one embodiment, the positive pickup unit (33) may be installed to swing together with the swing roller (32) on the first width direction side of the swing roller (32), and the negative pickup unit (34) may be installed to swing together with the swing roller (32) on the second width direction side of the swing roller (32).

[0092] Specifically, the positive pickup unit (33) may be installed to face the positive magazine (41) when the folding unit (31, 32) is placed at the first relative position, and to face the stack table (2) when the folding unit (31, 32) is placed at the second relative position.

[0093] Likewise, at this time, the negative pickup unit (34) may be installed to face the negative magazine when the folding unit (31, 32) is placed at the second relative position, and to face the stack table (2) when the folding unit (31, 32) is placed at the first relative position.

[0094] According to this structure, the operation of the folding unit (31, 32) folding the separator (10) can be linked at the precise timing with the operation of the positive pickup unit (33) and the negative pickup unit (34) picking up the positive (11) and the negative (12).

[0095] According to one embodiment, the stacking step (S1) can begin with the folding unit (31, 32) positioned at the first relative position, so that the cathode pickup unit (34) picks up the cathode (12) and faces the stack table (2). Subsequently, the first cycle (C1) is repeated a predetermined odd number of times until the electrode assembly (1) is completed. Specifically, the stacking step (S1) can be performed in the order that the cathode (12) is stacked first, the anode (11) and the cathode (12) are alternately and repeatedly stacked, and finally the cathode (12) is stacked. After the stacking step (S1) is completed, the folding unit (31, 32) can be positioned at the second relative position so that the separator (10) covers the last stacked cathode (12).

[0096] FIG. 15 shows a pulling step performed according to one embodiment. Referring again to FIG. 10, the electrode stacking method includes a pulling step (S2) in which the electrode assembly (1) is pulled in the first width direction while the folding unit (31, 32) is placed at the second relative position. According to one embodiment, a pulling unit (5) may be used to perform the pulling step (S2).

[0097] The electrode stacking device includes a pulling unit (5) disposed on the first width direction side of the stack table (2) and gripping the completed electrode assembly (1) from the stack table (2) and pulling it in the first width direction.

[0098] The electrode stacking device has the advantage of being time-efficient, as the pulling unit (5) is positioned on the opposite side of the width direction of the cathode magazine (42) relative to the stack table (2), so that while the separator (10) is being pulled and cut, the stacking unit (3) can pick up the cathode (12) and simultaneously stack the first sheet of the cathode (12) while the completed electrode assembly (1) is being discharged.

[0099] Referring again to FIG. 15, as the pulling unit (5) pulls the electrode assembly (1) in the first width direction, the separator (10) can be unfolded and extended between the folding unit (31, 32) and the pulling unit (5).

[0100] FIG. 16 shows the fixed step and the cutting step performed according to one embodiment. Referring again to FIG. 10, the electrode stacking method may additionally include a cutting step (S4) between the pulling step (S2) and the folding step (S5) in which the separator (10) is cut between the stack table (2) and the pulling unit (5). As the cutting step (S4) is performed, the completed electrode assembly (1) can be separated from the folding unit (31, 32) and discharged.

[0101] Additionally, the electrode stacking method may further include a fixing step (S3) between the pulling step (S2) and the cutting step (S4) for fixing the separator (10) to the first width direction side of the upper surface of the stack table (2). Specifically, the fixing step (S3) may be performed simultaneously with the cutting step (S4). By fixing the separator (10) to the stack table (2) before the folding step (S5) begins, the alignment of the separator (10) with respect to the anode (11) and the cathode (12) can be maintained, and appropriate tension can be provided for the separator (10) to unfold and fold between the folding unit (31, 32) and the stack table (2).

[0102] According to one embodiment, a fixing unit (20) and a cutting unit (6) may be used to perform the fixing step (S3) and the cutting step (S4).

[0103] The stack table (2) may additionally include a fixing unit (20) configured to fix an end of the separator (10) on the first width direction side of its upper surface. The fixing unit (20) can maintain alignment of the separator (10) with respect to the anode (11) and the cathode (12) by fixing the separator (10) to the stack table (2), and can provide appropriate tension to allow the separator (10) to unfold and fold between the folding unit (31, 32) and the stack table (2).

[0104] According to one embodiment, the fixing unit (20) may be configured to adsorb and fix the separator (10). However, the fixing unit (20) may have any shape or structure as long as it is capable of performing the operation of fixing and releasing the separator (10) to the upper surface of the stack table (2).

[0105] The electrode stacking device may further include a cutting unit (6) for cutting the separator (10) between the stack table (2) and the pulling unit (5). As the cutting unit (6) cuts the separator (10), the finished electrode assembly (1) can be separated from the folding unit (31, 32) and discharged.

[0106] According to one embodiment, the cutting unit may include a heat cutter that melts and cuts the separator (10). However, the cutting unit may have any shape or structure as long as it is capable of performing the operation of cutting the separator (10).

[0107] FIG. 17 shows a folding step performed according to one embodiment. Referring again to FIG. 10, the electrode stacking method includes a folding step (S5) in which the folding unit (31, 32) folds the separator (10) a predetermined odd number of times.

[0108] In the electrode stacking device described above, the cathode magazine (42) is positioned on the second width direction side and the pulling unit (5) is positioned on the first width direction side relative to the stack table (2). Accordingly, when the completed electrode assembly (1) is pulled in the first width direction, the folding unit (31, 32) is placed at the second relative position, and the cathode pickup unit (34) is placed in a state where it cannot immediately stack the cathode (12). The electrode stacking method according to the present invention solves this problem by including the folding step (S5) in which the separator (10) is folded an odd number of times after the pulling step (S2).

[0109] In the above folding step (S5), the separator (10) may be folded once. However, the number of times the separator (10) is folded in the above folding step (S5) may be any number of times, provided that it is an odd number of times so that the stacking unit (3) can be placed at the first relative position with the cathode pickup unit (34) picking up the cathode (12) just before the above folding step (S5) ends and a new stacking step (S1) begins.

[0110] Referring again to FIG. 10, the electrode stacking method is configured such that a second cycle (C2) including the stacking step (S1), the pulling step (S2), the fixing step (S3), the cutting step (S4), and the folding step (S5) is repeated. Accordingly, by using the electrode stacking method, an electrode assembly can be manufactured efficiently without unnecessary interruptions or preparation time.

[0111] The electrode assembly described below may be manufactured using the electrode stacking device and / or the electrode stacking method according to the present invention, but the means and method of manufacturing are not limited thereto.

[0112] FIG. 18 shows an electrode assembly according to one embodiment, and FIG. 19 shows one cross-section thereof. Referring thereto, the electrode assembly (1) may include: a positive electrode (11); a negative electrode (12) arranged alternately with the positive electrode (11) along a stacking direction; and a separator (10) that is folded in a zigzag and stacked together with the electrode (10). Each layer of the zigzag-folded separator (10) is interposed between the positive electrode (11) and the negative electrode (12), so that the positive electrode (11) and the negative electrode (12) can be used in a battery reaction while being isolated from each other by the separator (10).

[0113] The electrode assembly (1) according to the present invention is characterized in that the lowest and uppermost layers among the arrangement of the anode (11) and the cathode (12) are composed of the cathode (12), and the separator (10) includes a multilayer portion () folded in an even number of layers on the lower side of the cathode (12) constituting the lowest layer.

[0114] Here, the statement that the multilayer section is folded into an even number of layers means that the multilayer section is overlapped into an even number of layers along the stacking direction. For example, the multilayer section may be folded once to form two layers, with two layers overlapping each other in the stacking direction and having one folding section. Or, for example, the multilayer section may be folded three times to form four layers, with four layers overlapping each other in the stacking direction and having three folding sections.

[0115] According to one embodiment, the multilayer portion may be formed in two layers for the energy density of the electrode assembly (1).

[0116] The above separator (10) may include a plurality of folding portions. Specifically, the folding portion refers to a portion of the separator (10) that has a shape that is substantially bent 180 degrees so that it has a leading edge facing the first width direction or the second width direction. The separator (10) may form a zigzag shape by connecting the folding portions that are alternately formed on the first width direction side and the second width direction side along the stacking direction.

[0117] At this time, the folding portion () may include: a first folding portion (F1) that wraps around the first width direction side of the cathode (12); a second folding portion (F2) that wraps around the second width direction side of the anode (11); and an odd number of third folding portions (F3) that constitute the multilayer portion ().

[0118] However, the above folding portion may include other folding portions in addition to the first folding portion (F1), the second folding portion (F2), and the third folding portion (F3). For example, the above folding portion may be formed above the cathode (12) constituting the uppermost layer, so as not to surround either the anode (11) or the cathode (12), and not to constitute the multilayer portion.

[0119] At this time, the positive electrode (11) and the negative electrode (12) are arranged alternately, and as the negative electrode (12) constitutes the uppermost and lowermost layers of the arrangement, the negative electrode (12) may be one more than the positive electrode (11). Here, as the first folding part (F1) and the second folding part (F2) are provided in a number corresponding to the positive electrode (11) and the negative electrode (12), respectively, the number of the first folding part (F1) may be one more than the number of the second folding part (F2).

[0120] Independently thereof, it is preferable that the third folding part () be an even number. This means that even if the folding part () includes other folding parts in addition to the first folding part (F1), the second folding part (F2), and the third folding part (F3), it is preferable that the total number of the folding part () be an even number.

[0121] The embodiments described above should be understood as exemplary in all respects and not limiting, and the scope of the invention will be defined by the claims set forth below rather than by the detailed description above. Furthermore, the meaning and scope of the claims set forth below, as well as all modifications and variations derived from equivalents thereof, should be interpreted as being included within the scope of the invention.

[0122] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

1. Stack table; An anode magazine disposed on the first width direction side of the stack table above and loaded with anodes; A cathode magazine disposed on the second width direction side of the stack table above, with cathodes loaded therein; A stacking unit for manufacturing an electrode assembly by stacking a separator that is folded in a zigzag pattern on the stack table and the anode and cathode interposed between each layer of the separator; and A pulling unit disposed on the first width direction side of the stack table and gripping the completed electrode assembly from the stack table and pulling it in the first width direction; The above stacking unit is: A folding unit that folds the separator in a zigzag pattern while moving back and forth relative between a first relative position set in the first width direction and a second relative position set in the second width direction based on the stack table above; A positive electrode pickup unit that picks up the positive electrode from the above positive electrode magazine and stacks it on the separator; and An electrode stacking device comprising: a cathode pickup unit that picks up the cathode from the cathode magazine and stacks it on the separator.

2. In claim 1, the folding unit is: A supply roller for continuously supplying the above-mentioned separator; and A swing roller that reciprocates swinging below the supply roller and folding the separator in a zigzag pattern on both sides in the width direction; The above positive pickup unit swings together with the swing roller on the first width direction side of the swing roller, and The above-mentioned cathode pickup unit is an electrode stacking device that swings together with the swing roller on the second width direction side of the swing roller.

3. In claim 2, the positive pickup unit faces the positive magazine when the folding unit is placed at the first relative position, and faces the stack table when the folding unit is placed at the second relative position, and The above-described cathode pickup unit is an electrode stacking device that faces the cathode magazine when the folding unit is placed at the second relative position and faces the stack table when the folding unit is placed at the first relative position.

4. An electrode stacking device according to claim 1, wherein the stack table further comprises a fixing unit configured to fix an end of the separator membrane to the first width direction side of its upper surface.

5. An electrode stacking device according to claim 4, wherein the fixing unit is configured to adsorb and fix the separator.

6. The electrode stacking device of claim 1, wherein the electrode stacking device further comprises a cutting unit for cutting the separator between the stack table and the pulling unit.

7. An electrode stacking device according to claim 6, wherein the cutting portion includes a thermal cutter that melts and cuts the separator.

8. An electrode stacking method using the electrode stacking apparatus of Claim 1, wherein A stacking step in which the electrode assembly is completed on the stack table by repeating a first cycle, comprising a first step in which the stacking unit stacks either the anode or the cathode on the stack table, and a second step in which the stacking unit folds the separator once, a predetermined odd number of times; A pulling step in which, with the folding unit positioned at the second relative position, the pulling unit pulls the electrode assembly in the first width direction; and An electrode stacking method in which a second cycle is repeated, sequentially comprising a folding step in which the above-mentioned folding unit folds the above-mentioned separator a predetermined odd number of times.

9. The electrode stacking method of claim 8, wherein the electrode stacking method further comprises a cutting step of cutting the separator between the stack table and the pulling unit between the pulling step and the folding step.

10. The electrode stacking method of claim 9, wherein the electrode stacking method further comprises a fixing step of fixing the separator to the first width direction side of the upper surface of the stack table between the pulling step and the cutting step.

11. An electrode stacking method according to claim 8, wherein the separator is folded once in the folding step.

12. Anode; A cathode arranged alternately with the anode along the stacking direction; and A separator folded in a zigzag pattern and stacked together with the electrode; comprising, The lowest and uppermost layers of the arrangement of the anode and the cathode are composed of the cathode, and The above separator is an electrode assembly comprising a multilayer section folded in an even number of layers below the cathode constituting the lowest layer.

13. In claim 12, the separator comprises a plurality of folding portions, and The above folding part is: A first folding part that surrounds the first width direction side of the above-mentioned cathode; A second folding part surrounding the second width direction side of the above-mentioned anode; and An electrode assembly comprising an odd number of third folding sections constituting the above multilayer section.

14. An electrode assembly according to claim 13, wherein the number of the first folding portions is one more than the number of the second folding portions.

15. The electrode assembly according to claim 13, wherein the folding portion is an even number of electrodes.

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