Electrode assembly, method of manufacturing the same, and battery cell including the same

Abstract

According to an embodiment of the present invention, an electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Electrode tabs extending from the positive electrode or the negative electrode include a tab assembly portion in which a plurality of electrode tabs are gathered at one point by being pressed. A lower surface of the tab assembly portion has a first height with respect to one surface of the electrode assembly based on a stacking direction of the electrode assembly. The first height is a difference between a thickness of the electrode assembly and a first distance. The first distance corresponds to a sum of a thickness of the tab assembly portion and a thickness of a half-cell located at the outermost periphery of the electrode assembly.

Description

[Technical Field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0131841 dated October 5, 2021 and Korean Patent Application No. 10-2022-0124170 dated September 29, 2022, and all contents disclosed in the documents of said Korean patent applications may be incorporated as part of this specification.

[0002] The present invention relates to an electrode assembly, a manufacturing method thereof, and a battery cell including the same, and more particularly to an electrode assembly capable of preventing breakage of an electrode tab and a battery cell including the same. [Background technology]

[0003] In modern society, the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, leading to active development of technologies related to these mobile devices. Furthermore, rechargeable secondary batteries are used as a power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and other vehicles, as a solution to address air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and there is an increasing need for the development of secondary batteries.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting the most attention due to their advantages of being able to be charged and discharged freely, having a low self-discharge rate, and having a high energy density.

[0005] Depending on the shape of the battery case, secondary batteries are classified into cylindrical batteries and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch batteries, in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet.

[0006] Secondary batteries can also be classified by the structure of the electrode assembly, which is a stack of positive and negative electrodes and a separator between them. Representative examples include a jelly-roll (wound) electrode assembly, in which long sheet-type positive and negative electrodes are wound up with a separator between them, and a stack (layered) electrode assembly, in which multiple positive and negative electrodes cut to a specified size are stacked in sequence with a separator between them.

[0007] Meanwhile, in manufacturing a stacked electrode assembly to be built into a pouch-type battery, electrode tab portions to be coupled with electrode leads are gathered by being pressed by a tab guide and then prewelded. Here, the tab guide can gather the electrode tabs in the center so that the electrode tabs have a symmetrical shape, or gather them on one side so that the electrode tabs have an asymmetrical shape. However, when the electrode tabs are formed in an asymmetrical shape, there is a problem that the tension acting on each tab is different, which frequently causes the electrode tabs to break. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide an electrode assembly in which breakage of electrode tabs is prevented, and a battery cell including the same.

[0009] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0010] An electrode assembly according to one embodiment of the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Electrode tabs extending from the positive electrode or the negative electrode include a tab assembly portion formed by compressing a plurality of electrode tabs to one point. A lower surface of the tab assembly portion has a first height with respect to one surface of the electrode assembly in a stacking direction of the electrode assembly. The first height is a difference between a thickness of the electrode assembly and a first distance. The first distance corresponds to the sum of a thickness of the tab assembly portion and a thickness of a half-cell located at the outermost periphery of the electrode assembly.

[0011] The electrode tab may extend from an electrode of opposite polarity to the electrode included in the outermost half-cell.

[0012] The electrode tab may be a tab extending from one of the positive electrode or the negative electrode, and the outermost half cell may include the other of the positive electrode or the negative electrode.

[0013] The electrode tab may be a positive electrode tab connected to a positive electrode.

[0014] The first distance may be within 1 mm of the sum of the thickness of the tab assembly and the thickness of a half-cell located at the outermost periphery of the electrode assembly.

[0015] The first height may be greater than 6.2 mm and less than 8.2 mm.

[0016] The first height may be equal to or greater than 6.3 mm and equal to or less than 8.1 mm.

[0017] A manufacturing method of an electrode assembly according to another embodiment of the present invention is performed using an electrode assembly manufacturing apparatus including a tab guide, and includes the steps of adjusting a centering position of the tab guide to a first height, forming a tab gathering portion by pressing electrode tabs of the electrode assembly with the tab guide, and forming a tab joining portion by joining the closely spaced electrode tabs, wherein the first height is a difference between a thickness of the electrode assembly and a first distance, and the first distance corresponds to the sum of the thickness of the tab gathering portion and the thickness of a half-cell located at the outermost periphery of the electrode assembly.

[0018] The electrode tab may extend from an electrode of opposite polarity to the electrode included in the outermost half-cell.

[0019] The electrode tab may be a tab extending from one of the positive and negative electrodes, and the outermost half cell may include the other of the positive and negative electrodes.

[0020] The first distance may have a value that is different from the sum of the thickness of the tab assembly and the thickness of a half-cell located at the outermost periphery of the electrode assembly by 1 mm or less.

[0021] The method may further include calculating the first height before adjusting the centering position to the first height.

[0022] Before the step of adjusting the centering position to the first height, the method may further include the steps of calculating the first distance and calculating the first height based on the calculated first distance.

[0023] A battery cell according to another embodiment of the present invention includes the above-described electrode assembly.

[0024] A pouch-type battery cell according to another embodiment of the present invention includes the above-described electrode assembly. [Effects of the Invention]

[0025] According to the embodiments, the electrode assembly, the manufacturing method thereof, and the battery cell including the same of the present invention can prevent the tension acting on each tab from exceeding a certain level by adjusting the shape of the electrode tab.

[0026] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0027] [Figure 1] 10A to 10C are cross-sectional views showing a process for manufacturing a tab shape of an electrode assembly. [Figure 2] 1 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention. [Figure 3] FIG. 1 is a cross-sectional view of a tab-shaped electrode assembly and a battery cell. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the present invention. The present invention may be embodied in various forms other than those described below, and is not limited to the embodiments described herein.

[0029] In order to clearly describe the present invention, parts not necessary for the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0030] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily enlarged or reduced for the convenience of explanation, and it is obvious that the present invention is not necessarily limited to those shown. In the following drawings, thicknesses are enlarged to clearly show multiple layers and regions. In the following drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0031] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where the layer, film, region, plate, or other part is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" the direction opposite to gravity. Meanwhile, just as when something is described as being "on" or "above" a part, being "below" or "below" a part should be understood with reference to the above content.

[0032] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this means that it may further include other elements, not excluding other elements, unless otherwise specified.

[0033] Also, throughout the specification, "in a plane" means a portion of the subject matter viewed from above, and "in cross section" means a portion of the subject matter viewed from the side along a vertical cross section.

[0034] An electrode assembly according to an embodiment of the present invention will now be described.

[0035] FIG. 1 is a cross-sectional view showing a tab-shaped manufacturing process of an electrode assembly.

[0036] The electrode assembly 100 of this embodiment may be a power generating element capable of charging and discharging. The electrodes included in the electrode assembly 100 may include a positive electrode 110 and a negative electrode 120, and a separator 130 may be interposed between the electrodes, so that the electrode assembly 100 may have a structure in which the positive electrode 110, the separator 130, and the negative electrode 120 are alternately stacked. The positive electrode 110 or the negative electrode 120 may be formed by coating a positive electrode active material or a negative electrode active material on a current collector, and the separator 130 may be made of an insulating material to electrically insulate the positive electrode 110 from the negative electrode 120.

[0037] In addition, the electrode assembly 100 shown in FIG. 1 may be formed by stacking a plurality of mono-cells, each mono-cell being a unit cell stacked with a separator 130 / cathode 110 / separator 130 / anode 120 or a separator 130 / anode 120 / separator 130 / cathode 110 from the bottom, and a half-cell, each half-cell being a unit cell stacked with a separator 130 / anode 120 / separator 130 or a separator 130 / cathode 110 / separator 130 from the bottom, at the outermost periphery.

[0038] An electrode tab may be located at one end of the electrode assembly 100 or at one end of the electrodes (positive electrode 110, negative electrode 120) included in the electrode assembly 100. The electrode tab may be a portion extending in one direction or both directions from each electrode (positive electrode 110, negative electrode 120). The electrode tab may be a portion to which an electrode active material is not applied. Among the electrode tabs, the electrode tab connected to the positive electrode 110 may be referred to as a positive electrode tab 112, and the electrode tab connected to the negative electrode 120 may be referred to as a negative electrode tab. In this case, the positive electrode tab 112 may be located at one end of the electrode assembly 100, and the negative electrode tab may be located at the other end of the electrode assembly 100.

[0039] The electrode assembly 100 is connected to an electrode lead. The electrode tabs can be packed together by being pressed into one position using a tab guide or the like, and the packed electrode tabs can be joined by pre-welding. The packed electrode tabs are then connected to the electrode lead by welding or the like. Depending on the location where the electrode tabs are packed together, the electrode tabs can have a symmetrical or asymmetrical shape.

[0040] The process of forming the shape of the positive electrode tab 112 will be described in more detail below. While the following description focuses on the shape of the positive electrode tab 112 extending from the positive electrode 110, this does not preclude the application of the same to the negative electrode tab.

[0041] In addition, in the following description, it should be made clear that expressions referring to specific positions in the configuration, such as the top end, bottom end, and underside, can be based on what is shown above and what is shown below in the cross section of the electrode assembly 100 shown in the drawings.

[0042] 1 , the shape of the electrode tab can be formed by an electrode assembly manufacturing apparatus. The electrode assembly manufacturing apparatus can include a tab guide 200 that applies pressure to the electrode tab and a pre-welding apparatus 300. Here, the tab guide 200 can include a first guide 210 and a second guide 220 and can apply pressure to the electrode tab to form the tab shape.

[0043] The positive electrode tab 112 extending from one end of the positive electrode 110 may be inserted between the first guide 210 and the second guide 220. The first guide 210 and the second guide 220 may approach each other to apply pressure to the positive electrode tab 112. As a result, the positive electrode tabs 112 may be gathered together at a single point, and each positive electrode tab 112 may be bent to gather at a single point. The bent positive electrode tabs 112 may form an angle with the length direction of the electrode assembly 100. The portion where the electrode tabs are gathered together at a single point and thus form a slope may be referred to as a "tab slope portion 113," and the point where the electrode tabs are pressed may be referred to as a "tab gathering portion 114."

[0044] The positive electrode tab 112 pressed by the tab guide 200 may be welded by a pre-welding device 300. The pre-welding device 300 may be a device capable of ultrasonic welding. The pre-welding device 300 that provides ultrasonic welding may include a horn 310 and an anvil 320, and the electrode tab extending from the tab assembly 114 may be inserted between the horn 310 and the anvil 320 and welded. The electrode tab extending from the tab assembly 114 and welded in this manner may be referred to as a "tab joint 115." Meanwhile, the pre-welding device 300 only forms the tab joint 115 by applying heat to both sides of the electrode tab extending from the tab assembly 114, but is not intended to adjust its shape. Therefore, the shape of the tab joint 115 may be determined primarily by the shape of the tab assembly 114.

[0045] The shape of the electrode tab may be determined by the position of a point where the tab guide 200 presses the electrode tab. The position of the tab assembly 114 based on the stacking direction of the electrode assembly 100 may be determined by the centering position of the tab guide 200, and the overall shape of the electrode tab may be determined. Here, the stacking direction may also refer to the direction in which the electrodes and separators are stacked in the electrode assembly 100.

[0046] 1, when forming the tab assembly 114, the centering position of the tab guide 200 may be set to correspond to the position of the outermost electrode of the electrode assembly 100. Thus, the position of the tab assembly 114 based on the stacking direction of the electrode assembly 100 may correspond to the position of the outermost electrode of the electrode assembly 100. The position of the lower surface of the tab assembly 114 or the tab coupling portion 115 may correspond to the position of the outermost electrode of the electrode assembly 100.

[0047] When the position of the lower surface of the tab assembly 114 is calculated as the value of the "height (h, not shown) of the tab assembly 114" based on one surface of the electrode assembly 100, the height (h) of the tab assembly 114 may have an initial height (h0) value corresponding to the thickness value of the electrode assembly 100. The initial height (h0) may hereinafter be referred to as the "thickness of the electrode assembly 100."

[0048] 1, the position of the lower surface of the tab assembly 114 corresponds to the position of the outermost electrode located at the top of the electrode assembly 100, so the upper surface of the tab assembly 114 and / or the tab connecting portion 115 may be located higher than the top of the electrode assembly 100. As a result, in the electrode assembly 100, the tab assembly 114 and / or the tab connecting portion 115 may be located higher than the top of the electrode assembly 100.

[0049] In addition, the electrode assembly 100 is housed in a battery cell pouch to be manufactured as a pouch cell. If the tab assembly 114 or tab connecting portion 115 is located above the top end of the electrode assembly 100, some of the electrode tabs may be pulled during the process of sealing the electrode assembly 100 in the battery cell case, which may result in breakage. In addition, if the centering position is set as shown in Figure 1, there is a problem that the electrode tabs may interfere with the tab guide 200 and the pre-welding device 300 during the process of applying pressure to the electrode tabs and welding them.

[0050] Therefore, this embodiment aims to provide an electrode assembly 100 and a manufacturing method thereof that minimizes the above-mentioned problems by changing the shape of the electrode tabs from the conventional one. The electrode assembly 100 and the manufacturing method thereof of this embodiment changes the centering position of the tab guide 200, thereby changing the shape of the electrode tabs, i.e., the position of the tab assembly portion 114, and forming a margin in the electrode tabs, thereby preventing breakage of the electrode tabs.

[0051] The electrode assembly 100 of this embodiment will be described in more detail below with reference to FIG.

[0052] FIG. 2 is a cross-sectional view showing an electrode assembly according to one embodiment of the present invention.

[0053] 2, when the tab assembly 114 is formed in the electrode assembly 100 of this embodiment, the centering position of the tab guide 200 can be set to a position a predetermined distance away from the outermost electrode. By adjusting the centering position, the position of the lower surface of the tab assembly 114 can be positioned lower than the uppermost end of the electrode assembly 100, thereby preventing the above-mentioned phenomenon of the electrode tabs lifting up. When the position of the lower surface of the tab assembly 114 is calculated as the value of the "height (h) of the tab assembly 114" based on one surface of the electrode assembly 100, the height (h) of the tab assembly 114 can have a value of a first height (h1) that is smaller than a value of an initial height (h0), which is the thickness of the electrode assembly 100.

[0054] Here, the predetermined distance may be referred to as a first distance. In FIG. 2, the first height (h1), which is the height value of the lower surface of the tab assembly 114, may correspond to a value obtained by subtracting the first distance from the initial height (h0), which corresponds to the thickness of the electrode assembly 100.

[0055] At this time, the first distance can be calculated taking into consideration the thickness of the half cell and the electrode tab located at the outermost periphery of the electrode assembly 100.

[0056] Specifically, to prevent the tab assembly 114 from rising up, the centering position may need to be adjusted downward by the thickness of the tab assembly 114. The thickness of the tab assembly 114 may correspond to the thickness of the positive electrode tabs 112 and may be referred to as the second thickness (t2). That is, the centering position may need to be adjusted downward by the second thickness (t2) or by a value slightly larger or smaller than the second thickness (t2).

[0057] Also, when the negative electrode half cell is located at the outermost periphery of the electrode assembly 100 as shown in FIG. 2, the centering position may need to be adjusted downward by the thickness of the half cell to prevent the tab assembly 114 from rising up. The thickness of the half cell may be referred to as the first thickness (t1). That is, the centering position may need to be adjusted downward by the first thickness (t1) or by a value slightly larger or smaller than the first thickness (t1).

[0058] Therefore, the first distance may correspond to the sum of the first thickness (t1) and the second thickness (t2). Here, "corresponding" may mean not only that the first distance and the sum of the first thickness (t1) and the second thickness (t2) are equal, but also that the first distance and the sum of the first thickness (t1) and the second thickness (t2) may differ within a predetermined range. The first height (h1) may correspond to the thickness (h0) of the electrode assembly 100 minus the first thickness (t1) and the second thickness (t2).

[0059] In particular, in the case of a pouch-type battery cell, when one side of the pouch is flat and the other side houses the electrode assembly 100 (so-called one-cup cell), the electrode tab lifting phenomenon can be prevented. At this time, the electrode tab (positive electrode tab 112) extending from the electrode 110 (positive electrode) of the opposite polarity to the electrode 120 (negative electrode) included in the half cell located at the outermost periphery of the electrode assembly 100 is prevented from lifting, and the tab assembly part 114 can be maintained flat.

[0060] For example, in the case of a pouch battery cell, which is a one-cup cell, the top of the outermost stack cell is a half cell, and the half cell does not have a positive electrode tab. When implemented as in the present invention, the electrode tab (positive electrode tab 112) extending from the positive electrode 110 of the opposite polarity to the negative electrode 120 included in the half cell located at the outermost edge of the electrode assembly 100 is prevented from floating, and the tab assembly 114 can be maintained flat.

[0061] Below, we will describe experiments and their results for selecting the optimized centering position and the position of the tab group 114. The experiments described below are for setting the optimized centering position and determining an appropriate first distance.

[0062] The thickness (h0) of the electrode assembly 100 used in the following experiments is 7.6 mm to 7.7 mm, the thickness (t1) of the outermost half cell is 0.24 mm, and the thickness (t2) of the positive electrode tab 112 is 0.21 mm.

[0063] FIG. 3 shows a cross section of a tab-shaped electrode assembly and battery cell.

[0064] The table in FIG. 3 is for comparing the effect of the tab shape depending on the height (h) of the tab assembly 114, and shows four cases of height (h) values ​​of 5.2 mm, 6.2 mm, 7.2 mm, and 8.2 mm.

[0065] In this case, since the sum of the first thickness (t1) and the second thickness (t2) is 0.45 mm, the value obtained by subtracting the sum of the first thickness (t1) and the second thickness (t2) from the thickness (h0) of the electrode assembly 100 can be 7.15 mm to 7.25 mm. Therefore, 5.2 mm can be expressed as [(h0) - {(t1) + (t2) + 2}] mm, 6.2 mm can be expressed as [(h0) - {(t1) + (t2) + 1}] mm, 7.2 mm can be expressed as [(h0) - {(t1) + (t2)}] mm, and 8.2 mm can be expressed as [(h0) - {(t1) + (t2) - 1}] mm. In other words, the table of FIG. 3 describes the cases where the first distance differs from the sum of the first thickness (t1) and the second thickness (t2) by -1, 0, +1, or +2.

[0066] 3 shows the results of measuring the shape of the electrode tab using a 3D camera, with the horizontal axis representing the measured distance and the vertical axis representing the depth value. A larger value on the vertical axis, i.e., a larger depth value, indicates that the tab shape is bent, resulting in a larger margin being formed on the electrode tab.

[0067] According to the experimental results, when the height (h) of the tab assembly 114 is 5.2 mm or 6.2 mm, it was observed that the electrode tabs located at the bottom were pulled when the electrode assembly 100 was inserted into the cell case. Considering this, it was confirmed that when the height (h) of the tab assembly 114 is 6.2 mm or less, excessive tension is applied to some of the electrode tabs of the battery cell, which increases the risk of the electrode tabs breaking.

[0068] On the other hand, if the height (h) of the tab assembly 114 is 8.2 mm, the pre-welding process is performed at a relatively high position, which may cause the tab assembly 114 or the tab connecting portion 115 to float above the outermost electrode. Therefore, if the height (h) of the tab assembly 114 is 8.2 mm or more, excessive tension may be applied to the electrode tabs located at the top after the electrode assembly 100 is inserted into the cell case, as with the conventional electrode assembly 100, which may result in breakage of the electrode tabs.

[0069] However, when the height (h) value of the tab assembly 114 is 7.2 mm, the graph shows that the electrode tabs have a large depth overall, and the cross-sectional image of the battery cell does not show that excessive tension is generated in any particular tab. Therefore, compared to other cases, when the height (h) value of the tab assembly 114 is 7.2 mm, it can be confirmed that an appropriate margin is formed in the electrode tabs, and breakage of the electrode tabs may be minimized.

[0070] Considering the above results, it is preferable that the height (h) of the lower surface of the tab assembly 114 based on one surface of the electrode assembly 100 is greater than 6.2 mm and less than 8.2 mm. The height (h) of the lower surface of the tab assembly 114 may be greater than 6.3 mm and less than 8.1 mm, or greater than 6.7 mm and less than 7.7 mm, and preferably between 7.15 mm and 7.25 mm.

[0071] Therefore, the appropriate height (h) of the tab assembly 114, i.e., the first height (h1), may be the thickness (h0) of the electrode assembly 100 minus the first distance, where the first distance may be within 1 mm of the sum of the thickness (t1) of the half cell and the thickness (t2) of the positive electrode tab 112. The first distance may be greater than {(t1) + (t2) - 1} mm and less than {(t1) + (t2) + 1} mm. The first height may be greater than [h0 - {(t1) + (t2) + 1}] mm and less than [h0 - {(t1) + (t2) - 1}] mm. The first height may be greater than [h0 - {(t1) + (t2) + 0.9}] mm and less than [h0 - {(t1) + (t2) - 0.9}] mm. Alternatively, the first height can be equal to or greater than [h0-{(t1)+(t2)+0.5}] (mm) and equal to or less than [h0-{(t1)+(t2)-0.5}] (mm).

[0072] A method for manufacturing an electrode assembly according to an embodiment of the present invention will now be described. It should be noted that the numbers in parentheses, such as S1000, are not actually shown in the drawings, but are used to easily distinguish between steps.

[0073] The electrode assembly manufacturing method described below can be performed by an electrode assembly manufacturing apparatus including the above-described tab guide 200 and full pre-welding device 300. The electrode assembly manufacturing apparatus described in this embodiment may include a controller, and the operation of the electrode assembly manufacturing apparatus may be controlled through the controller. In addition to the controller, the electrode assembly manufacturing apparatus may further include a measurement unit, an input unit, and / or a communication unit, and may measure the thickness of the electrode assembly 100, etc. through the measurement unit, receive information input from a user through the input unit, and receive information from an external device through the communication unit. In addition, information measured, input, or received by the electrode assembly manufacturing apparatus may be processed by the control unit.

[0074] The manufacturing method (S1000) of the electrode assembly of this embodiment includes: Step S1100: adjusting the centering position of the tab guide 200 to a first height h1; forming a tab assembly 114 (S1200); The step of forming the tab connection portion 115 (S1300) may be included.

[0075] In step (S1100), the centering position of the tab guide 200 may be adjusted based on a first height (h1). Here, the first height (h1) may be a value obtained by subtracting a first distance from an initial height (h0) corresponding to the thickness of the electrode assembly 100. The first distance may be a value corresponding to the sum of a first thickness (t1) corresponding to the thickness of the half cell and a second thickness (t2) corresponding to the thickness of the positive electrode tab 112. More specifically, the first distance may be equal to or greater than {(t1) + (t2) - 1} mm and equal to or less than {(t1) + (t2) + 1} mm.

[0076] Meanwhile, according to an embodiment, the first height (h1) and / or the first distance may be a value calculated by a control unit included in the electrode assembly manufacturing apparatus including the tab guide 200 and / or the pre-welding device 300, or may be a value input by a user or received from an external device.

[0077] In addition, the thickness (h0), the first thickness (t1) and / or the second thickness (t2) of the electrode assembly 100 may be values ​​measured by a measuring unit included in the above-mentioned electrode assembly manufacturing apparatus, input by a user, or received from an external device.

[0078] Therefore, the manufacturing method of the electrode assembly (S1000) of this embodiment may include a step of acquiring the first height (h1) before the step of adjusting the centering position of the tab guide 200 to the first height (h1) (S1100). Here, the step of acquiring the first height (h1) may be embodied as a step of receiving the first height (h1) through the input unit or receiving it from an external device through the communication unit. Alternatively, the step of acquiring the first height (h1) may be embodied as a step of calculating the first height (h1). In this case, the step of calculating the first height (h1) may be performed by the control unit.

[0079] Here, calculating the first height (h1) may include acquiring a first distance and calculating the first height based on the first distance. The acquiring the first distance may be embodied as receiving the first distance from a user via an input unit or from an external device via a communication unit. Alternatively, acquiring the first distance may be embodied as calculating the first distance. The calculating the first distance may be performed by a control unit.

[0080] Here, the step of calculating the first distance may include the steps of acquiring the thickness (h0), the first thickness (t1), and / or the second thickness (t2) of the electrode assembly 100, and calculating the first distance based on the acquired values. In this case, the "step of acquiring the thickness (h0), the first thickness (t1), and / or the second thickness (t2) of the electrode assembly 100" may be embodied as the step of measuring the values ​​via a measurement unit, receiving them from a user via an input unit, or receiving them from an external device via a communication unit.

[0081] In step S1200, the tab guide 200 may form the tab assembly 114 by pressing the electrode tabs of the electrode assembly.

[0082] Step (S1200) may include inserting the positive electrode tab 112 between the first guide 210 and the second guide 220, moving the first guide 210 and the second guide 220 toward each other, applying pressure to the positive electrode tab 112, and forming a tab assembly portion 114 on the positive electrode tab 112.

[0083] In step S1300, the closely spaced electrode tabs may be bonded to form a tab bonded portion 115. The tab bonded portion 115 may be joined through welding. The pre-welding device 300 may form the tab bonded portion 115 by heating the closely spaced electrode tabs through welding.

[0084] The step S1300 may include a step in which the pre-welding device 300 heats the crowded positive electrode tabs 112 and a step in which the tab joints 115 are formed on the positive electrode tabs 112.

[0085] Meanwhile, the electrode assembly 100 of this embodiment described above can be housed in a cell case together with an electrolyte and provided to a battery cell.

[0086] A battery cell according to an embodiment of the present invention may include an electrode assembly 100 in which a plurality of electrodes and a plurality of separators are alternately stacked, electrode leads connected to electrode tabs extending from the plurality of electrodes, and a cell case that seals the electrode assembly with one end of the electrode lead protruding.

[0087] The battery cells described above may be stacked in one direction to form a battery cell stack, or may be modularized to form a battery pack together with a Battery Management System (BMS) that manages the temperature and voltage of the battery and / or a cooling device. The battery pack may be applied to various devices. For example, the device to which the battery pack is applied may be a means of transportation such as an electric bicycle, an electric vehicle, or a hybrid vehicle. However, the devices described above are not limited thereto, and the battery pack according to this embodiment may be used in various devices other than the above examples, which also fall within the scope of the present invention.

[0088] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0089] 100 Electrode Assembly 110 Positive electrode 112 Positive electrode tab 120 negative electrode 130 Separation membrane 200 Tab Guide 300 Pre-welding Equipment

Claims

1. a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; an electrode tab extending from the positive electrode or the negative electrode includes a tab gathering portion in which a plurality of electrode tabs are gathered into one point by being pressed; a lower surface of the tab assembly has a first height with respect to one surface of the electrode assembly in a stacking direction of the electrode assembly; the first height is a difference between a thickness of the electrode assembly and a first distance; The electrode assembly, wherein the first distance is within 1 mm of the sum of the thickness of the tab assembly and the thickness of a half-cell located at the outermost periphery of the electrode assembly.

2. 2. The electrode assembly of claim 1, wherein the electrode tab extends from an electrode of opposite polarity to the electrode included in the outermost half-cell.

3. the electrode tab is a tab extending from either the positive electrode or the negative electrode, The electrode assembly of claim 1 , wherein the outermost half cell includes the other of the positive electrode and the negative electrode.

4. The electrode assembly according to claim 1 , wherein the electrode tab is a positive electrode tab connected to the positive electrode.

5. The electrode assembly of claim 1 , wherein the first height is greater than 6.2 mm and less than 8.2 mm.

6. 2. The electrode assembly of claim 1, wherein the first height is greater than or equal to 6.3 mm and less than or equal to 8.1 mm.

7. A method for manufacturing an electrode assembly performed by an electrode assembly manufacturing apparatus including a tab guide, adjusting a centering position of the tab guide to a first height; forming a tab assembly by pressing the electrode tabs of the electrode assembly with the tab guide; and forming a tab joint by joining the closely spaced electrode tabs; the first height is a difference between a thickness of the electrode assembly and a first distance; The method for manufacturing an electrode assembly, wherein the first distance is a value that is within 1 mm of the sum of the thickness of the tab assembly and the thickness of a half-cell located at the outermost periphery of the electrode assembly.

8. The method for manufacturing an electrode assembly according to claim 7 , wherein the electrode tab extends from an electrode having a polarity opposite to that of the electrode included in the outermost half-cell.

9. The electrode tab is a tab extending from either a positive electrode or a negative electrode, The method of claim 7 , wherein the outermost half cell includes the other of the positive electrode and the negative electrode.

10. Before the step of adjusting the centering position to the first height, The method for manufacturing an electrode assembly according to claim 7 , further comprising the step of calculating the first height.

11. Before the step of adjusting the centering position to the first height, calculating the first distance; and The method for manufacturing an electrode assembly according to claim 7 , further comprising the step of calculating the first height based on the calculated first distance.

12. A battery cell comprising the electrode assembly according to any one of claims 1 to 6.

13. A pouch-type battery cell comprising the electrode assembly according to any one of claims 1 to 6.

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