Cutting device, electrode assembly, battery cell, electrode assembly processing device, battery pack and vehicle including the same, and method for manufacturing a battery cell.

Abstract

The present invention discloses a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and a vehicle including the same, and a method for manufacturing a battery cell. The present invention provides a cutting device including: a first cutter unit 210 that moves in the axial direction of the electrode assembly 110 while forming a first cutting line 113 in the axial direction on the uncoated portion 15 extending in the axial direction, and separates the portion to be cut 115a and the portion to be formed 117a based on the first cutting line 113; and a second cutter unit 220 that moves in the radial direction of the electrode assembly 110 while forming a second cutting line 16a in the circumferential direction on the uncoated portion 15 wound in the circumferential direction, and cuts out the first cutting line 113, an outer portion 117b of the portion to be formed 117a surrounded by the second cutting line 16a, and the portion to be cut 115a, so that the second cutting line 16a is connected to the first cutting line 113, thereby forming a cut surface portion 115 in the uncoated portion 15 of the electrode assembly 110.

Description

[Technical Field]

[0001] This application claims priority rights under Korean Patent Application No. 10-2021-0155213 dated November 11, 2021, and Korean Patent Application No. 10-2022-0079449 dated June 29, 2022, and all content disclosed in the documents of said Korean Patent Applications is incorporated herein by reference.

[0002] The present invention relates to a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell. [Background technology]

[0003] Typically, secondary batteries consist of a positive electrode, a negative electrode, and an electrolyte, and generate electrical energy through chemical reactions. Due to their high applicability across product lines and electrical characteristics such as high energy density, secondary batteries are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical sources.

[0004] These rechargeable batteries have the primary advantage of dramatically reducing the use of fossil fuels. They also have the advantage of producing no by-products from energy use. For these reasons, rechargeable batteries are attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0005] Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of each of these individual rechargeable battery cells, i.e., each battery cell 100, is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Alternatively, depending on the required charge and discharge capacity of the battery pack, multiple battery cells 100 can be connected in parallel to form a battery pack. Thus, the number of battery cells included in the battery pack and the electrical connection configuration can be set in various ways depending on the required output voltage and / or charge and discharge capacity.

[0006] On the other hand, cylindrical, prismatic, and pouch-type battery cells are known as types of unit secondary battery cells. In the case of a cylindrical battery cell, an insulating separator membrane is interposed between the positive and negative electrodes, and this is wound up to form a jelly roll-type electrode assembly, which is inserted into the inside of a battery can to constitute a battery. Strip-shaped electrode tabs may be connected to the blank portions of the positive and negative electrodes. The electrode tabs electrically connect the electrode assembly to the electrode terminals exposed to the outside. For reference, the positive electrode terminal is the cap plate of the sealing body that seals the opening of the battery can, and the negative electrode terminal is the battery can. However, with conventional cylindrical battery cells having such a structure, current concentrates on the strip-shaped electrode tabs connected to the blank portion of the positive electrode and / or the blank portion of the negative electrode, resulting in high resistance, high heat generation, and poor current collection efficiency. In other words, the cross-sectional area of ​​the electrode tabs decreases rapidly, which can cause a bottleneck phenomenon in current flow.

[0007] Small cylindrical battery cells with 18650 or 21700 form factors do not pose significant issues with resistance and heat generation. However, when increasing the form factor of cylindrical battery cells for application in electric vehicles, a problem can arise where the cylindrical battery cells ignite during the fast charging process, generating a lot of heat around the electrode tabs.

[0008] To solve such problems, a cylindrical battery cell having a structure with improved current collection efficiency is presented, in which a positive electrode non-coated portion and a negative electrode non-coated portion are respectively located at the upper and lower ends of a jelly roll type electrode assembly, and current collection plates are welded to these non-coated portions (so-called Tab-less cylindrical battery cell).

[0009] The first electrode sheet and the second electrode sheet have a structure in which an active material is coated on a sheet-like current collector, and include a non-coated portion on one long side along the winding direction.

[0010] The electrode assembly is manufactured by sequentially laminating the first electrode sheet and the second electrode sheet together with two separator films and then winding them in one direction. At this time, the non-coated portions of the first electrode sheet and the second electrode sheet are arranged in opposite directions to each other.

[0011] After the winding process, the non-coated portion of the first electrode sheet and the non-coated portion of the second electrode sheet are bent toward the core side. Thereafter, current collection plates are welded and joined to the non-coated portions respectively.

[0012] No electrode tabs are separately connected to the positive electrode non-coated portion and the negative electrode non-coated portion, and the current collection plates are connected to external electrode terminals, so that a current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly. Therefore, there is an advantage of reducing the resistance of the battery cell. This is because the resistance is inversely proportional to the cross-sectional area of the path through which the current flows.

[0013] In a Tab-less cylindrical battery cell, in order to improve the welding characteristics of the non-coated portion and the current collection plate, a strong pressure must be applied to the welding point of the non-coated portion to bend the non-coated portion as flat as possible.

[0014] However, when bending the weld points of the plain section, the pattern of the plain section may deform and become irregularly distorted. In this case, the deformed area may come into contact with an electrode plate of the opposite polarity, causing an internal short circuit or causing microscopic cracks in the plain section. Also, the plain section adjacent to the core of the electrode assembly may bend and block all or a portion of the cavity in the core of the electrode assembly. In this case, problems arise in the electrolyte injection process. That is, the cavity in the core of the electrode assembly is used as a passage through which the electrolyte is injected. However, if this passage is blocked, it becomes difficult to inject the electrolyte. In addition, during the process of inserting the electrolyte injection machine into the cavity, interference with the plain section near the core may occur, potentially causing the plain section to tear.

[0015] Furthermore, the bent portions of the plain sections where the current collector plates are welded must overlap in multiple layers, and there should be no gaps. Only in this way can sufficient welding strength be obtained, and even when using the latest technologies such as laser welding, it is possible to prevent the laser from penetrating into the electrode assembly and damaging the separation membrane or active material.

[0016] Korean Published Patent Publication No. 2022-0023100 (published March 2, 2022) discloses a cylindrical secondary battery with an improved current collection structure. In cylindrical secondary batteries, the current collection plate is welded in line contact with the end of the blank section, which leads to a problem in which the weld cross-sectional area between the current collection plate and the blank section is reduced by the gap between the blank section. As a result, the electrical resistance in the weld cross-sectional area, which is the current passage, increases, which can increase the amount of heat generated in the battery cell and increase the possibility of ignition.

[0017] Korean Published Patent Publication No. 2016-0110610 (September 22, 2016) discloses a secondary battery and a cylindrical lithium secondary battery. These secondary batteries disclose a configuration in which a first current collector plate is electrically connected so as to be in direct contact with a first blank area, and a second current collector plate is electrically connected so as to be in direct contact with a second blank area. However, this also has the problem that the contact cross-sectional area between the current collector plate and the blank area is reduced by the gap between the blank areas, because the first and second current collector plates are connected in a state where they are in line contact with the ends of the first and second blank areas, respectively. There are limitations to increasing the contact cross-sectional area. [Overview of the Initiative] [Problems that the invention aims to solve]

[0018] The present invention was devised to solve the above-mentioned problems and aims to provide a cutting device that can increase the welding cross-sectional area of ​​the electrode assembly and the current collector plate and expand the current path, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell.

[0019] Furthermore, the present invention aims to provide a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell, which can suppress the increase in heat generation of the battery cell and reduce the possibility of ignition even when the electrode assembly is applied to a large-capacity battery cell.

[0020] Furthermore, the present invention aims to provide a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell, which can prevent the boundary between the forming portion and the cut surface portion from tearing or deforming while being irregularly distorted.

[0021] Furthermore, the present invention aims to provide a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell, which can reduce the amount of heat generated by a battery cell or significantly reduce the possibility of explosion.

[0022] Furthermore, the present invention aims to provide a cutting device, an electrode assembly, a battery cell, an electrode assembly processing device, a battery pack and vehicle including the same, and a method for manufacturing a battery cell, which improve the cutting speed of the plain portion and enable the formation of a smooth cut surface.

[0023] The technical problems of the present invention are not limited to the objectives mentioned above. Other objectives and advantages of the present invention not mentioned can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, it is clear that the objectives and advantages of the present invention can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0024] To solve the above-mentioned problems, the present invention can be applied to an electrode assembly that includes a jelly roll-shaped electrode cell body portion formed by laminating and winding a first electrode sheet and a second electrode sheet having opposite polarities, and a separation film for insulation between them.

[0025] The sheets can be stacked in the following order: first electrode sheet, separation membrane, second electrode sheet, separation membrane.

[0026] The winding can be performed along the length direction of the stacked sheets. The axial length of the resulting jelly roll-type electrode cell body may correspond to the width of the stacked sheets.

[0027] At least one of the first electrode sheet and the second electrode sheet is provided with a plain area at its widthwise end where the active material layer is not coated. This ensures that the plain area is located at the axial end of the electrode cell body. The plain area can be located on either side of the axial end of the electrode cell body, or on both sides.

[0028] The plain portion of the electrode cell body of the electrode assembly comprises a plurality of cut surfaces formed by cutting off a portion of the plain portion. For example, a plurality of cut surfaces can be formed by cutting off the outer portion of the portion to be formed and the portion to be cut. The plain portion remaining after cutting off a portion constitutes the portion to be formed.

[0029] Multiple cut surfaces are arranged circumferentially around the core. The forming portion is positioned between two adjacent cut surfaces in the circumferential direction.

[0030] The electrode assembly includes a plurality of forming portions formed by bending the portion to be formed.

[0031] The aforementioned cut surface portion can be formed in a fan shape along the circumferential direction, centered on the core portion of the electrode cell body.

[0032] The cross-section portion may have a central angle of 30° to 180°. More specifically, the cross-section portion may have a central angle of 45° to 180°, and more preferably, a central angle of 60° to 120°.

[0033] The aforementioned cut surface can be formed by cutting a portion that is a certain distance outward in the axial direction from the boundary between the plain portion and the textured portion. In other words, the cut surface can be said to be formed by cutting the plain portion of the textured portion.

[0034] The outer end of the portion to be formed may be separated from the outer circumferential surface of the electrode cell body by a certain distance toward the center of the electrode cell body. The portion to be formed can be described as having a certain section removed from the outer circumferential surface of the electrode cell body toward the center.

[0035] The axial height of the portion to be formed can be set to be less than the distance between the outer end of the portion to be formed and the outer circumferential surface of the electrode cell body.

[0036] The forming portion can be formed radially around the core portion of the electrode cell body.

[0037] The forming portion can be formed in such a way that the portion to be formed is bent outward in the radial direction of the electrode cell body portion and laid horizontally.

[0038] The forming portion may be configured such that a certain section is removed from the outer circumferential surface of the electrode cell body portion toward the center.

[0039] The forming portions can be formed in a radial direction relative to the electrode cell body portion.

[0040] The electrode cell body can be formed in a cylindrical shape.

[0041] The core portion can be formed in a hollow shape that penetrates the center of the electrode cell body portion.

[0042] The core portion is formed in a hollow shape that penetrates the center of the electrode cell body portion, and the forming portion is laid horizontally radially outward and does not obstruct the core portion in the axial direction. The removal of the blank portion can be performed after the winding process is completed.

[0043] In this way, when forming the cut surface, the outer portion of the forming area and the cutting area are cut simultaneously. Therefore, even if the forming area is bent radially outward, the laid-down forming area does not obstruct the core portion of the electrode assembly.

[0044] The present invention provides a battery cell including the electrode assembly.

[0045] The battery cell includes a battery can containing the electrode assembly and electrically connected to either the first electrode sheet or the second electrode sheet to have a first polarity; a sealing cap portion that seals the open end of the battery can; and a first current collector plate electrically connected to the other of the first electrode sheet or the second electrode sheet to have a second polarity.

[0046] The first current collector plate can be electrically connected by fixing it to the forming portion of the electrode assembly by welding or other means.

[0047] Either the first electrode sheet or the second electrode sheet can be directly connected to the battery can, or connected via the second current collector plate.

[0048] The battery can may include a support portion that further protrudes radially inward from the inner circumference of the battery can. The support portion can support the sealing cap portion.

[0049] The battery cell may further include an insulator to prevent short circuits of opposite polarities.

[0050] The insulator can be interposed between the battery can and the sealed cap portion to provide insulation between them. More specifically, the insulator can be interposed between the outer circumferential surface of the sealed cap portion and the inner circumferential surface of the battery can, and between the support portion and the sealed cap portion.

[0051] The insulator can be interposed between the battery can and the first current collector plate to provide insulation between them. For example, the insulator can be interposed between the first current collector plate and the support portion.

[0052] The present invention provides a battery pack comprising at least one of the aforementioned battery cells.

[0053] The present invention provides an automobile comprising at least one of the aforementioned battery packs.

[0054] The present invention provides a cutting device for cutting off a blank portion provided at the axial end of the electrode cell body portion of the electrode assembly.

[0055] The cutting device includes a first cutter section that moves axially on the electrode assembly and forms a first cutting line in the axial direction on the blank portion, and a second cutter section that moves radially on the electrode assembly and forms a second cutting line in the circumferential direction on the blank portion.

[0056] The second cutter section forms a second cutting line that cuts a portion of the plain section wound in the circumferential direction, but the second cutting line is formed so as to be connected to the first cutting line.

[0057] By connecting the first cutting line and the second cutting line, the plain portion surrounded by the first cutting line and the second cutting line can be cut off.

[0058] The present invention provides a processing apparatus that includes a cutting device and a pressing unit for bending the forming portion that remains after being cut off by the cutting device.

[0059] The pressing unit forms the forming portion by applying pressure to the portion of the plain portion that is to be formed and laying it down.

[0060] The forming portion is pressed radially by the pressing portion, thereby bending the portion corresponding to the second cutting line and allowing it to lie horizontally in the radial direction.

[0061] The first cutter section may include a plurality of first blades arranged radially within the first cutter section.

[0062] The first blade extends in the axial direction and can form a cutting edge at its axial tip.

[0063] The first cutter section may further include a first vibration generating section. The first vibration generating section may generate minute vibrations.

[0064] The second cutter section forms a cut surface on the plain portion of the electrode assembly by cutting off the outer portion of the portion to be formed and the portion to be cut.

[0065] The second cutter section includes a second blade formed in a triangular shape with blades on both sides to cut the portion to be cut in a fan shape, and a third blade connected to one side of the second blade and having a blade formed to cut the outer portion of the portion to be formed.

[0066] The third blade can be formed in a triangular shape with blades on both sides.

[0067] The blade on one side of the second blade may be formed to be longer than the length of the first cutting line, and the blade on the other side of the second blade may be formed to be shorter than the length of the first cutting line.

[0068] The third blade can be connected to the outer end of the other blade of the second blade.

[0069] One side of the third blade can be formed to the same length as the width of the forming area.

[0070] The length of the other side of the third blade can be formed to be less than or equal to the length of the one side of the third blade.

[0071] The second cutter section may further include a second vibration generating section. The second vibration generating section may generate minute vibrations.

[0072] The pressing unit can move radially (radially) outward from the electrode cell body while positioning the plain portion intended for forming radially outward from the electrode cell body.

[0073] The present invention provides a method for manufacturing the battery cells described above.

[0074] The manufacturing method for these battery cells includes the step of laminating a first electrode sheet, a second electrode sheet, and a separation membrane, and then winding them up to produce an electrode assembly.

[0075] As a result, the electrode assembly can include an electrode cell body portion in which both the electrode sheet and the separation membrane are wound.

[0076] The electrode cell body portion may be cylindrical.

[0077] The electrode cell body portion may include a hollow core portion.

[0078] At least one of the first electrode sheet and the second electrode sheet includes a plain area on either side edge in the width direction where the active material layer is not applied. When both the first electrode sheet and the second electrode sheet have plain areas, these plain areas can be provided on both sides of the width direction, respectively.

[0079] This allows the electrode cell body portion to be provided with a plain portion that extends and protrudes in the axial direction at its axial end.

[0080] The outer portion of the forming area and the portion to be cut can be cut to form the cut surface.

[0081] The removal of the blank areas can also be performed after the electrode laminate has been wound up to form the electrode cell body. These processes can be carried out, for example, by a cutter equipped with an ultrasonically vibrating blade.

[0082] The method for manufacturing the battery cell includes the step of removing a portion of the blank area provided at the axial end of the electrode cell body.

[0083] Specifically, the blank portion removal step includes the step of separating the portion to be cut from the portion to be formed by moving the first cutter portion in the axial direction of the electrode cell body portion and forming a first cutting line in the blank portion of the first electrode sheet and the second electrode sheet in the axial direction.

[0084] Multiple first cutting lines can be provided. Multiple first cutting lines can be arranged radially.

[0085] Furthermore, the blank area removal step includes, after the formation of the first cutting line, a step in which the second cutter portion moves radially inward from the outer circumference of the battery cell while forming a second cutting line in the circumferential direction on the blank area.

[0086] Multiple second cutting lines can be provided. The second cutting lines extend in the circumferential direction, and multiple second cutting lines can be aligned in the radial direction.

[0087] The lengths of the multiple second cutting lines in the direction may gradually increase as you move radially from the core side to the outer circumference side.

[0088] The second cutter section moves radially through the electrode cell body section and forms a second cutting line in the circumferential direction on the plain section that has been wound in the circumferential direction. When the second cutting line is connected to the first cutting line, the outer portion of the forming section and the cutting section, which are surrounded by the first and second cutting lines, can be cut off.

[0089] The radial length of the electrode cell body portion of the forming-planned portion is formed to be shorter than the length of the first cutting line.

[0090] The axial height of the electrode cell body portion of the forming-plan portion is formed to be less than the distance between the outer end of the forming-plan portion and the outer circumferential surface of the electrode cell body portion.

[0091] The cut surface formed at the location where the plain portion has been removed can be formed in a fan shape along the circumferential direction, centered on the core portion of the electrode cell body.

[0092] The aforementioned cut surface portion may have a central angle of 60° to 120°.

[0093] The method for manufacturing the battery cell may further include the step of forming a forming portion by applying pressure to the unformed portion remaining after being cut off by the cutting line, on the radially outward side of the electrode cell body portion, thereby laying it radially outward.

[0094] The bending process can be performed by pressing the forming portion radially outward using a press unit.

[0095] The forming portion can be formed radially around the core portion of the electrode cell body.

[0096] The forming portion can be formed such that the portion to be formed on the blank portion lies radially outward from the electrode cell body portion.

[0097] The forming portion can be formed along the radial direction of the electrode cell body portion.

[0098] The aforementioned cut surface can be formed by cutting a portion that is a certain distance outward in the axial direction from the boundary between the plain portion and the textured portion.

[0099] The first cutter unit can cut the plain portion while vibrating due to the first vibration generating unit. The first cutter unit may be an ultrasonic cutter.

[0100] The second cutter section can cut the plain section while vibrating due to the second vibration generating section. The second cutter section may be an ultrasonic cutter. [Effects of the Invention]

[0101] According to the present invention, since the forming portion is welded in surface contact with the current collector plate, the current path between the electrode assembly and the current collector plate can relatively increase as the area of ​​the forming portion increases.

[0102] According to the present invention, the forming portion increases the current path by an area equal to the spacing between the plain portions. Therefore, even when applied to high-capacity battery cells, it is possible to suppress the increase in heat generation of the battery cells and reduce the possibility of ignition.

[0103] According to the present invention, after the portion to be cut and the portion to be formed in the plain area are separated from each other, the outer portion of the portion to be formed and the portion to be cut are cut to form a cut surface, and the portion to be formed is pressed radially outward and laid down to form the formed portion. This prevents the boundary between the formed portion and the cut surface from tearing or deforming irregularly when the portion to be formed is pressed.

[0104] According to the present invention, it is possible to prevent the boundary between the forming portion and the cut surface portion from tearing or deforming, thereby preventing contact with the electrode sheet of the opposite polarity at the torn or deformed portion.

[0105] According to the present invention, in order to prevent the boundary between the plain and textured areas from tearing or deforming, it is possible to prevent the active material coated on the textured area from detaching from the textured area or from weakening of the bonding force. This makes it possible to suppress a decrease in the performance and capacity of the battery cell.

[0106] According to the present invention, it is possible to prevent the edges of the separation membrane from lifting or being damaged by torn or deformed portions at the boundary. This prevents short circuits between the first electrode sheet and the second electrode sheet. Furthermore, it is possible to reduce the amount of heat generated by the battery cell or significantly reduce the possibility of explosion.

[0107] According to the present invention, by cutting the plain portion extending in the axial direction in the area that does not constitute the forming portion, a cut surface portion can be formed, thereby reducing the length occupied by the plain portion in the axial direction at both ends of the electrode cell body portion. This allows for further securing of the axial volume of the electrode cell body portion housed in the battery can. Therefore, the electrical capacity relative to the volume of the battery cell can be further increased.

[0108] According to the present invention, the second cutter unit cuts both the outer portion of the forming section and the cutting section simultaneously, thereby shortening the manufacturing time of the electrode assembly.

[0109] The effects described above, as well as the specific effects of the present invention, will be explained and described below in conjunction with the descriptions of embodiments for carrying out the invention. [Brief explanation of the drawing]

[0110] [Figure 1] This is a schematic plan view showing the electrode cell stack according to the present invention. [Figure 2]Figure 1 is a cross-sectional view showing the electrode cell stack cut in the AA direction. [Figure 3] This is a perspective view showing the electrode cell body portion after the electrode cell stack shown in Figure 1 has been wound up. [Figure 4] This is a perspective view showing the state in which the first cutter portion according to the present invention has cut the electrode cell body portion. [Figure 5] This is a perspective view showing the first cutter section according to the present invention. [Figure 6] This is a rear view showing the first cutter section according to the present invention. [Figure 7] This is a plan view showing the state in which the first cutter unit according to the present invention has cut the plain portion of the electrode cell body to form a first cutting line. [Figure 8] This is a perspective view showing the state of the second cutter section according to the present invention before it cuts the plain portion of the electrode cell body. [Figure 9] This is a plan view showing the second cutter section according to the present invention. [Figure 10] This is a side view showing the second cutter section according to the present invention cutting the plain portion of the electrode cell body. [Figure 11] This is a plan view showing the second cutter section according to the present invention cutting the portion of the blank area that is to be cut. [Figure 12] This is a plan view showing the second cutter section according to the present invention after cutting the outer portion of the plain area intended for forming and the portion intended for cutting. [Figure 13] This is a perspective view showing the second cutter section according to the present invention after cutting the outer portion of the forming section and the cutting section. [Figure 14] This is a perspective view showing the press section according to the present invention in which the forming section has been formed by folding the forming section radially outward and laying it down. [Figure 15] This is a side view showing the press section according to the present invention in which the forming section is bent radially outward to form the forming section. [Figure 16]This is a flowchart illustrating the method for manufacturing a battery cell according to the present invention. [Figure 17] This is a cross-sectional view showing the electrode assembly according to the present invention. [Figure 18] This is a perspective view showing the electrode assembly according to the present invention housed in a pack housing. [Figure 19] This is a perspective view showing the battery pack according to the present invention installed in a vehicle. [Modes for carrying out the invention]

[0111] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0112] The present invention is not limited to the embodiments disclosed below, and can be modified in various ways and embodied in various different forms. However, these embodiments are provided to complete the disclosure of the present invention and to fully inform those in the ordinary skill of the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, and should be understood to include any modifications, equivalents, or substitutions that fall within the technical spirit and scope of the present invention, as well as the substitution or addition of any configuration of one embodiment to that of another embodiment.

[0113] The accompanying drawings are provided to facilitate understanding of the embodiments disclosed herein and should not be understood as limiting the technical concept disclosed herein, but rather as including any modifications, equivalents, or substitutions that fall within the concept and technical scope of the present invention. Components in the drawings may be exaggerated in size or thickness to appear larger or smaller for ease of understanding, but this should not be interpreted as restricting the scope of protection of the present invention.

[0114] The terms used herein are used solely to describe specific examples or embodiments and are not intended to limit the invention. Furthermore, singular expressions include plural expressions unless otherwise clearly indicated in the context. Terms such as "includes" and "contains" in the specification are intended to indicate the existence of features, figures, stages, operations, components, parts, or combinations thereof described herein. That is, terms such as "includes" and "contains" in the specification should not be understood as preemptively excluding the existence or possibility of adding one or more other features, figures, stages, operations, components, parts, or combinations thereof.

[0115] Terms including ordinal numbers, such as "first," "second," etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely for the purpose of distinguishing one component from others.

[0116] When it is mentioned that one component is “linked” or “connected” to another component, it must be understood that it is directly linked to or may be connected to the other component, but that other components may exist in between. On the other hand, when it is mentioned that one component is “directly linked” or “directly connected” to another component, it must be understood that there are no other components in between.

[0117] When one component is described as being "above" or "below" another component, it must be understood that this means not only is it positioned directly above the other component, but other components may exist between them.

[0118] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as they would be generally understood by a person of ordinary skill in the art to which this invention pertains. Terms that are commonly used, similar to those defined in dictionaries, should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not, unless explicitly defined in this application, should be interpreted in an ideal or overly formal sense.

[0119] The following describes an electrode assembly according to an embodiment of the present invention.

[0120] For the sake of explanation, the direction along the length of the winding shaft of the electrode assembly 110 wound into a jelly roll in this specification is referred to as the axial direction (Y). The direction surrounding the winding shaft is referred to as the circumferential direction (X) or circumferential direction. The direction that is closer to or further away from the winding shaft is referred to as the radial direction or radial direction (Z). Of these, the direction that is closer to the winding shaft is referred to as the centripetal direction, and the direction that is further away from the winding shaft is referred to as the centrifugal direction.

[0121] Figure 1 is a schematic plan view showing the electrode cell stack according to the present invention, Figure 2 is a cross-sectional view showing the electrode cell stack of Figure 1 cut in the AA direction, and Figure 3 is a perspective view showing the electrode cell body portion manufactured by winding up the electrode cell stack of Figure 1.

[0122] Referring to Figures 1 to 3, the electrode stack 10 according to an embodiment of the present invention includes a first electrode sheet 11, a second electrode sheet 12, and a separation membrane 13. The electrode stack 10 is formed by laminating a separation membrane 13 between a sheet-like first electrode sheet 11 and a second electrode sheet 12. For example, the electrode stack 10 may consist of one first electrode sheet 11, one second electrode sheet 12, and two separation membranes 13. Alternatively, the electrode stack 10 may consist of two or more first electrode sheets 11, two or more second electrode sheets 12, and three or more separation membranes 13. As the number of first electrode sheets 11, second electrode sheets 12, and separation membranes 13 in these electrode stacks increases, the winding time and manufacturing time of the electrode assembly 110 of the desired diameter can be shortened.

[0123] The first electrode sheet 11 and the second electrode sheet 12 each include a textured portion 14 coated with an active material and a plain portion 15 not coated with an active material. The plain portion 15 can be formed on one side in the width direction of the first electrode sheet 11 and the second electrode sheet 12. At least a portion of the plain portion 15 can be used as an electrode tab on its own. When the electrode assembly 110 is wound into a cylindrical shape, the plain portion 15 of the first electrode sheet 11 may be positioned on one side in the axial direction (upper or lower side in Figure 1), and the plain portion 15 of the second electrode sheet 12 may be positioned on the other side in the axial direction.

[0124] The plain portion 15 of the first electrode sheet 11 and the plain portion 15 of the second electrode sheet 12 can be formed to have the same width. Alternatively, the plain portion 15 of the first electrode sheet 11 and the plain portion 15 of the second electrode sheet 12 can be formed to have different widths.

[0125] The first electrode sheet 11 may be a negative electrode sheet coated with a negative electrode active material, and the second electrode sheet 12 may be a positive electrode sheet coated with a positive electrode active material. Of course, the first electrode sheet 11 may be a positive electrode sheet coated with a positive electrode active material, and the second electrode sheet 12 may be a negative electrode sheet coated with a negative electrode active material.

[0126] The first electrode sheet 11 and the second electrode sheet 12 include a current collector made of metal foil and an active material layer. The metal foil may be aluminum or copper. The active material layer can be coated on one or both sides of the first electrode sheet 11 and the second electrode sheet 12.

[0127] The width of the plain section 15 is significantly narrower than the width of the textured section 14. The plain section 15 can be formed in the shape of a narrow band. The plain section 15 may also consist of multiple segmented pieces that are spaced apart along the length of the plain section 15 and formed in a sawtooth shape. The shape of the segmented pieces can be changed to a square, triangle, semicircle, inverted ellipse, parallelogram, etc.

[0128] In the present invention, the positive electrode active material coated on the first electrode sheet 11 and the negative electrode active material coated on the second electrode sheet 12 can be any active material known in the industry.

[0129] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; chemical formula Li 1+x Mn 2x Lithium manganese oxides (LiMnO2) such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7; chemical formula LiNi 1-x M x Lithiated nickel oxide, represented as O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); chemical formula LiMn 2-x M xLithium intercalation materials can be the main component, such as lithium manganese composite oxides represented as O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the lithium in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3; or composite oxides formed by combinations thereof. While there are such types of positive electrode active materials, they are not limited to these.

[0130] The positive electrode current collector has a thickness of, for example, 3 to 500 μm. These positive electrode current collectors are not particularly limited as long as they do not cause chemical changes in the battery and are conductive. For example, the positive electrode current collector can be made of stainless steel, aluminum, nickel, titanium, plastic carbon, or aluminum or stainless steel with a surface treatment of carbon, nickel, titanium, silver, etc. The electrode current collector can also have fine irregularities formed on its surface to increase the adhesion strength to the positive electrode active material. These electrode current collectors can take various forms, such as films, sheets, foils, nets, porous materials, foams, and nonwoven fabrics.

[0131] The positive electrode active material particles may be further mixed with conductive materials. These conductive materials are added, for example, in an amount of 1 to 50% by weight based on the total weight of the mixture containing the positive electrode active material. These conductive materials are not particularly limited as long as they do not cause chemical changes in the battery and have high conductivity. For example, the conductive materials can be graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or summer black; conductive fibers such as carbon fiber or metal fiber; metal powders such as carbon fluoride, aluminum, or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive oxides such as titanium oxide; or conductive materials such as polyphenylene derivatives.

[0132] Further, the negative electrode sheet is manufactured by applying and drying negative electrode active material particles on a negative electrode current collector, and may further contain components such as the above-described conductive material, binder, solvent, etc. as necessary.

[0133] The negative electrode current collector has, for example, a thickness of 3 to 500 μm. These negative electrode current collectors are not particularly limited as long as they do not cause a chemical change in the battery and have conductivity. For example, the negative electrode current collector can be made of copper, stainless steel, aluminum, nickel, titanium, plastic carbon, or a material obtained by surface-treating the surface of copper or stainless steel with carbon, nickel, titanium, silver, etc., or an aluminum-cadmium alloy, etc. Also, similar to the positive electrode current collector, fine irregularities can be formed on the surface to strengthen the binding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams, non-woven fabrics, etc.

[0134] The negative electrode active material is, for example, carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me 1-x Me’yO z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8) metal composite oxides; lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials, etc. can be used.

[0135] The binder polymer usable in the electrode sheets 11 and 12 is a component that helps to bond the electrode active material particles to conductive materials and to the electrode current collector, and is added in an amount of 1 to 50% by weight based on the total weight of the mixture containing the electrode active material. Examples of these binder polymers include polyvinylidene fluoride-co-hexafluoropropylene (PVdF), polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. Any binder polymer selected from the group consisting of propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, and carboxyl methyl cellulose, or a mixture of two or more of these, may be used, but is not limited thereto.

[0136] Non-limiting examples of solvents used in the manufacture of the aforementioned electrodes include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water, or mixtures thereof. These solvents provide an appropriate viscosity level so that a slurry coating layer is formed on the surface of the electrode current collector to the desired level.

[0137] The separation membrane 13 comprises a porous polymer substrate and a porous coating layer located on both sides of the porous polymer substrate, the coating layer containing inorganic particles and a binder polymer.

[0138] The porous polymer substrate may be a polyolefin-based porous substrate.

[0139] The porous polyolefin substrate may be in the form of a film or a non-woven web. Having a porous structure allows for smooth movement of the electrolyte between the positive and negative electrodes. The porous structure also increases the electrolyte impregnation of the substrate itself, ensuring excellent ion conductivity, preventing an increase in the internal resistance of the electrochemical element, and thus preventing a decrease in the performance of the electrochemical element.

[0140] The polyolefin porous substrate used in this invention can be any planar porous substrate commonly used in electrochemical elements, and its material and form can be selected in various ways depending on the purpose.

[0141] The polyolefin porous substrate may, but is not limited to, a film or non-woven web formed from high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, polypropylene, or a mixture of two or more of these.

[0142] Although the aforementioned porous polyolefin substrate can have a thickness of 8 to 30 μm, this is merely an example, and thicknesses outside this range can also be used, taking into consideration mechanical properties and the high-efficiency charge-discharge characteristics of the battery.

[0143] The separation membrane 13 according to the present invention can have a thickness of 1 to 100 μm or 5 to 50 μm. If the thickness of the separation membrane 13 is less than 1 μm, the function of the separation membrane 13 may not be fully exhibited, and deterioration of mechanical properties may occur. If the thickness of the separation membrane 13 is greater than 100 μm, the characteristics of the battery may deteriorate during high-efficiency charging and discharging. Furthermore, it can have a porosity of 40 to 60% and an air permeability of 150 to 300 seconds / 100 mL.

[0144] When using the separation membrane 13 according to one embodiment of the present invention, since porous coating layers are provided on both sides of the porous polymer substrate, the impregnation performance with the electrolyte is improved, a uniform solid electrolyte interface layer can be formed, and superior air permeability can be ensured compared to conventional cross-sectional inorganic coating separation membranes 13. For example, it may be within 120 s / 100 cc. Furthermore, even if inorganic porous coating layers are provided on both sides, the thickness can be the same as that of conventional cross-sectional inorganic coating separation membranes 13. For example, it may be within ~15.0 μm.

[0145] Furthermore, when using a separation membrane 13 according to one embodiment of the present invention, the stability of the separation membrane 13 is improved, and heat resistance and compression resistance can be ensured. Specifically, heat resistance with a thermal shrinkage characteristic of 5% or less based on 180°C can be ensured, and puncture strength of 550 gf or more can be ensured. In the battery cycle using these separation membranes 13, when core deformation occurs, damage or puncture of the separation membrane 13 at the stepped portion can be prevented.

[0146] We will now describe the electrode assembly manufactured using the electrode laminate described above.

[0147] Figure 4 is a perspective view showing the state in which the electrode cell body portion according to the present invention has been cut by the first cutter portion; Figure 5 is a perspective view showing the first cutter portion according to the present invention; Figure 6 is a rear view showing the first cutter portion according to the present invention; Figure 7 is a plan view showing the state in which the first cutter portion according to the present invention has cut the plain portion of the electrode cell body portion to form the first cutting line; Figure 8 is a perspective view showing the state before the second cutter portion according to the present invention cuts the plain portion of the electrode cell body portion; Figure 9 is a plan view showing the second cutter portion according to the present invention; and Figure 10 shows the state in which the second cutter portion according to the present invention cuts the electrode cell body portion Figure 11 is a side view showing the state of cutting the plain portion of the D portion, Figure 12 is a plan view showing the state of the second cutter unit according to the present invention cutting the portion of the plain portion that is to be cut, Figure 13 is a perspective view showing the state of the second cutter unit according to the present invention cutting the outer portion of the forming portion and the portion that is to be cut, Figure 14 is a perspective view showing the state of the press unit according to the present invention forming the forming portion by bending the portion of the forming portion radially outward and laying it down.

[0148] Referring to Figures 4 to 14, the electrode assembly 110 includes an electrode cell body portion 111, a plurality of cut surface portions 115, and a plurality of forming portions 117.

[0149] The electrode cell body portion 111 is a cylindrical portion wound in a jelly roll type, with a separation membrane 13 laminated between a sheet-like first electrode sheet 11 and a second electrode sheet 12. As described above, plain portions 15 without the active material layer coating are formed at the widthwise ends of the first electrode sheet 11 and the second electrode sheet 12, and these are arranged on one axial side and the other side of the electrode cell body portion 111, respectively, and extend in the axial direction.

[0150] The electrode cell body portion 111 can be formed by winding the longitudinally elongated laminate around a winding rod (not shown) and then withdrawing the winding rod from the electrode cell body portion 111. At this time, the more first electrode sheets 11, second electrode sheets 12, and separation membranes 13 are laminated on the electrode laminate 10, the shorter the winding time and manufacturing time of the electrode assembly 110 can be. A hollow core portion 112 is formed in the electrode cell body portion 111 where the winding rod has been withdrawn.

[0151] On one axial side of the electrode cell body 111, the plain portion 15 of the first electrode sheet 11 is exposed at a certain height, and on the other axial side of the electrode cell body 111, the plain portion 15 of the second electrode sheet 12 is exposed at a certain height.

[0152] The first cutter section 210 cuts the blank portion 15 of the electrode cell body section 111 in the axial direction, separating the portion to be cut 115a and the portion to be formed 117a in the circumferential direction. A first cutting line 113 is formed between the portion to be cut 115a and the portion to be formed 117a. The portion to be cut 115a and the portion to be formed 117a are arranged alternately along the circumferential direction of the electrode cell body section 111. The first cutting line 113 is formed to extend axially from the axial end of the blank portion 15 toward the electrode cell body section 111. At this time, the portion to be cut 115a and the portion to be formed 117a maintain their upright position along the axial direction of the electrode cell body section 111.

[0153] The second cutter section 220 removes the outer portion 117b (see Figures 7 and 8) of the forming portion 117a of the blank portion 15 and the cutting portion 115a from the electrode cell body portion 111 by cutting the lower axial portion in the radial direction. The second cutter section 220 forms a second cutting line 16a (see Figures 13 and 14) extending in the circumferential direction at the lower part of the blank portion 15 in the area corresponding to the outer portion 117b of the forming portion 117a and the cutting portion 115a. The second cutting line 16a is formed along the direction around the blank portion 15 and is provided at the lower part of each radially adjacent blank portion. When both circumferential ends of the second cutting line 16a are connected to the outer portion 117b of the forming portion 117a and the first cutting lines 13 on both sides of the forming portion 115a in the circumferential direction, the outer portion 117b of the forming portion 117a and the forming portion 115a, surrounded by the pair of first cutting lines 13 and the second cutting line 16a, separate from the electrode cell body portion 111. The short plain portion remaining after the outer portion 117b of the forming portion 117a and the forming portion 115a are cut off constitutes the cut surface portion 115.

[0154] As a result, the plain portion 15 of the electrode cell body portion 111 is provided with a cut surface portion 115 and a forming portion 117a.

[0155] The first cutter section 210 that cuts the first cutting line 113 can use an ultrasonic cutter to prevent buckling that may occur when cutting the thin plain section 15 in the axial direction.

[0156] The first cutter section 210 includes a plurality of first blades 211 arranged in a direction corresponding to the radial direction of the electrode cell body section 111, and a first vibration generating section 213 to which the first blades 211 are fixed.

[0157] The first vibration generating unit 213 includes a circular plate (not shown) and a vibration source (not shown) for vibrating the circular plate.

[0158] The plurality of first blades 211 may have their base ends fixed to the surface of the circular plate of the first vibration generating unit 213, extend in a direction corresponding to the axial direction of the electrode cell body unit 111, and have sharp blades 211a at their tips.

[0159] Multiple first blades 211 are arranged radially with respect to the center of the first vibration generating section 213. For example, a pair of first blades 211 defining the forming section 117a can be formed in a cross shape at four locations with respect to the center of the first vibration generating section 213. Alternatively, the pair of first blades 211 may be arranged radially at six locations at 60° intervals. Alternatively, a pair of second blades 221 may be arranged radially at three locations at 120° intervals. The angle (θ2) between these pairs of first blades 211 can be appropriately selected depending on the diameter of the electrode cell body section 111, the capacity of the battery pack, and the shape of the current collector plates 130, 140 welded thereto.

[0160] In the embodiment, a preferred structure is exemplified in which a pair of first blades 211 defining the forming portion 117a are arranged parallel to each other. However, the pair of first blades 211 do not necessarily have to be arranged parallel to each other. For example, the pair of first blades 211 may be arranged in such a way that the distance between them gradually increases as you move towards the centripetal direction, or in such a way that the distance between them gradually increases as you move towards the centripetal direction. Also, although the first blades 211 are exemplified as being straight, the first blades 211 do not necessarily have to be straight. For example, the first blades 211 may be gently curved.

[0161] The circumferential distance between a pair of first blades 211 and another pair of adjacent first blades 211 may become shorter as you move in the centrifugal direction and longer as you move in the centrifugal direction. That is, this can define the sector shape of the cut surface 115.

[0162] For the processing of the second cutting line 16a by the second cutter section 220 described later, it is preferable that the circumferential distance between the pair of first blades 211 and the other pair of first blades 211 adjacent to them is such that it does not increase as it moves in the centrifugal direction, or does not decrease as it moves in the centrifugal direction.

[0163] The first vibration generating unit 213 may include an ultrasonic transducer. A first communication hole 215 is formed in the center of the first vibration generating unit 213 so as to communicate with the core unit 112. The first vibration generating unit 213 vibrates ultrasonically when the first blade 211 is moved axially along the electrode cell body unit 111 and cuts the plain section 15.

[0164] The first blade 211 applies an axial force to the plain section 15, but this force is not used to process the first cutting line 113. When the plain section 15 is pressed, there is a possibility that deformation may occur, such as the plain section 15 buckling or the portion of the plain section 15 near the first cutting line 113 bending or breaking.

[0165] When the first blade 211 vibrates ultrasonically, the above-mentioned phenomena are prevented when the first blade 211 cuts the blank section 15, resulting in very smooth cutting. This improves the cutting speed of the blank section 15, allowing for the smooth formation of the first cutting line 113 of the blank section 15. These first vibration generating units 213 can be configured with various vibration methods as long as they vibrate the first blade 211.

[0166] At least one of the second cutter sections 220 can cut the blank portion 15 of the electrode assembly 110 to form a cut surface portion 115. For example, four second cutter sections 220 can move simultaneously to form a cut surface portion 115. Alternatively, two cutter sections 220 can move while forming two cut surface portions 115, and then form two more cut surface portions 115. Furthermore, one cutter section 220 can move while sequentially forming cut surface portions 115 one by one. Figure 8 illustrates a case where four cutter sections 220 cut the blank portion 15, but the invention is not limited to this.

[0167] Referring to Figures 8 to 11, the second cutter section 220 includes a second blade 221 that cuts the plain section 15 in the radial direction, a third blade 222 connected to one side of the second blade 221 that cuts the plain section 15 radially together with the second blade 221, and a second vibration generating section 223 to which the second blade 221 and the third blade 222 are fixed.

[0168] The second blade 221 may have a shape in which its width narrows towards the tip. Specifically, the second blade 221 may be triangular or wedge-shaped. The apex of the second blade 221 may be formed at an angle (θ3) of 60 to 120°. The angle (θ3) of the apex of the second blade 221 is formed to correspond to the central angle (θ1) of the cut surface portion 115, which will be described later. In this embodiment, it is illustrated that the second blade 221 has an apex angle (θ3) of approximately 90°. The second blade 221 may be double-edged. That is, blades 221a and 221b may be provided at positions corresponding to the two slanted portions extending to the tip.

[0169] The third blade 222 may have a shape in which its width narrows towards the tip. Specifically, the third blade 222 may be triangular or wedge-shaped. The apex of the third blade 222 may be formed at an angle (θ4) of 60 to 120°. In this embodiment, the third blade 222 is exemplified as having an apex angle (θ4) of approximately 90°. The third blade 222 may be double-edged. That is, blades 222a and 222b may be provided at positions corresponding to the two slanted portions extending to the tip.

[0170] Furthermore, the angle (θ4) of the apex of the third blade 222 is changed by the central angle (θ3) of the second blade 221. For example, if the central angle (θ3) of the second blade 221 is 60°, the central angle (θ4) of the third blade 222 is formed to be 120°. Conversely, if the central angle (θ3) of the second blade 221 is 120°, the central angle (θ4) of the third blade 222 is formed to be 60°. As a result, the other side blade 221b of the second blade 221 and the one side blade 222a of the third blade 222 form an angle of approximately 90°. Moreover, when the third blade 222 cuts the outer portion 117b of the forming target portion 117a, the outermost edge of the forming target portion 117a is formed in line with the tangent to the electrode cell body portion 111.

[0171] As the second blade 221 and the third blade 222 advance radially to form the second cutting line 16a, the pointed tip of the second blade 221 first cuts the central part of the blank portion 15 around the planned cutting portion 115a, and the third blade 222 cuts the central part of the outer portion 117b of the planned forming portion 117a. As the second blade 221 advances in the centrifugal direction, the double blades 221a and 221b expand the second cutting line 16a on both sides in the circumferential direction, and as the third blade 222 advances in the centrifugal direction, the double blades 222a and 222b expand the second cutting line 16a on both sides in the circumferential direction. When the second blade 221 and the third blade 222 apply force to the side surface of the plain section 15 in the radial direction, the large surface areas of the second blade 221 and the third blade 222 do not contact the side surface of the plain section 15 all at once. Instead, the force is concentrated at the pointed tips and applied to the plain section 15. Therefore, when forming the second cutting line 16a on the side surface of the plain section 15, the plain section 15 is not pushed laterally and does not deform. After the tips of the second blade 221 and the third blade 222 have cut through the plain section 15, as the second cutter section 220 moves in the centrifugal direction, the two edges 222a and 222b of the second blade 221 and the third blade 222 press circumferentially along the second cutting line 16a, cutting it open. The cutting method and direction of the second cutter section 220 minimize deformation of the plain section 15.

[0172] The second vibration generating unit 223 may include an ultrasonic transducer. The second vibration generating unit 223 vibrates ultrasonically when the second blade 221 and the third blade 222 are moved radially across the electrode cell body 111 while cutting the plain section 15. This improves the cutting speed of the plain section 15, allowing for the smooth formation of the cut surface 115. Various vibration methods can be applied to these second vibration generating units 223, as long as the second blade 221 and the third blade 222 are vibrated.

[0173] One side blade 221a of the second blade 221 is formed to be longer than the length (L2) of the first cutting line 113, and the other side blade 221b of the second blade 221 is formed to be shorter than the length (L2) of the first cutting line 113 (L11>L2, L12>L2). In this case, the third blade 222 is connected to the outer end of the other side blade 221b of the second blade 221. The combined length of the other side blade 221b of the second blade 221 (L12) and the length of one side blade 222a of the third blade 222 (L12+L21) may be the same as or approximately the same as the length of one side blade 221a of the second blade 221 (L11). The tip of the second blade 221 protrudes a certain height more than the tip of the third blade 222. As a result, after the second blade 221 enters the cutting portion 115a to a certain height or more, the tip of the third blade 222 enters the outer portion 117b of the forming portion 117a and cuts. In other words, the second blade 221 and the third blade 222 begin cutting the blank portion 15 with a slight time difference, but the point at which the blank portion 15 is cut is the same.

[0174] The length (L21) of one side blade 222a of the third blade 222 is formed to be the same length as, or slightly longer than, the width (W1) of the forming area 117a. This prevents the third blade 222 from getting caught on or colliding with the second blade 221 of an adjacent second cutter 220 when the four second cutter sections 220 cut the blank area 15 simultaneously.

[0175] The length (L22) of the other blade 222b of the third blade 222 is formed to be less than or equal to the length (L21) of the one blade 222a of the third blade 222. Less than half of the other blade 222b of the third blade 222 is used to cut the outside of the forming target portion 117a. Therefore, the other blade 222b can be formed only in a portion of the other side of the third blade 222.

[0176] Referring to Figures 11 to 14, the multiple cut surfaces 115 are formed by cutting off the outer portion 117b of the forming portion 117a, which is part of the plain portion 15, and the cutting portion 115a along the circumferential direction, centered on the core portion 112 of the electrode cell body portion 111. At this time, the multiple cut surfaces 115 may be arranged at equal intervals along the circumferential direction, centered on the core portion 112. Furthermore, the multiple cut surfaces 115 can be formed to be the same size and shape.

[0177] Multiple forming portions 117 are formed by applying pressure to the forming portion 117a of the blank portion 15, which is positioned between the cut surface portions 115, in a direction that intersects the axial direction, for example, radially outward, and laying it down. Multiple forming portions 117 can be formed by applying pressure to the forming portion 117a of the blank portion 15 using a press portion 230, which will be described later, and laying it down. In this case, multiple forming portions 117 may be formed by laying down multiple non-cut pieces that constitute the forming portion 117a while they are continuously overlapping. As a result, the forming portions 117 can be formed obliquely with respect to the axial direction of the electrode cell body portion 111, or they can be laid down completely and formed flat.

[0178] The multiple forming portions 117 described above are welded to the current collection plates 130 and 140 to form current paths. Furthermore, the multiple cut surface portions 115 can also be welded to the current collection plates 130 and 140. However, since the cut surface portions 115 are welded (for example, by laser welding) to the current collection plates 130 and 140 in a line contact state, the effect of increasing the current paths is not as significant for the cut surface portions 115 compared to the forming portions 117. On the other hand, since the forming portions 117 are formed by laying the portion to be formed 117a horizontally in the radial direction, the forming portions 117 cover the gaps between the plain portions 15 that are separated by the thickness of the separation film 13. Since these formed portions 117 are welded in surface contact with the current collection plates 130 and 140, the larger the area of ​​the formed portion 117, the relatively larger the current path between the electrode assembly 110 and the current collection plates 130 and 140 can be. Because these formed portions 117 increase the current path by the combined area of ​​the spacing between the plain portions 15, even when applied to a large-capacity battery cell 100, it is possible to suppress the increase in heat generation of the battery cell 100 and reduce the possibility of ignition.

[0179] If the cut surface portion 115 is exposed without being welded to the current collector plates 130 and 140, the impregnation of the electrolyte may increase when the electrolyte is injected into the electrode assembly 110. By bending the uncut piece, the impregnation of the electrolyte may be weakened in the forming portion 117 area, but since the cut surface portion 115 is adjacent to the forming portion 117 and complements it, there is no particular problem with electrolyte impregnation.

[0180] According to the present invention, the portion to be cut 115a and the portion to be formed 117a in the plain portion 15 are separated circumferentially from each other by the first cutter portion 210 which forms the first cutting line 113 in the axial direction. Then, the outer portion 117b of the portion to be formed 117a and the lower end of the portion to be cut 115a are cut by the second cutter portion 220 to form the cut surface portion 115, and the portion to be formed 117a is pressed radially outward and laid down to form the portion to be formed 117. This prevents the boundary between the portion to be formed 117 and the cut surface portion 115 (below the first cutting line 113) from tearing or deforming irregularly while being distorted when the portion to be formed 117a is pressed.

[0181] Furthermore, since the boundary between the forming portion 117 and the cut surface portion 115 (below the first cut line 113) can be prevented from tearing or deforming, contact with the electrode sheets 11 and 12 of the opposite polarity can be prevented at the torn or deformed portion. In addition, by preventing the boundary between the plain portion 15 and the textured portion 14 from tearing or deforming, the active material coated on the textured portion 14 can be prevented from detaching from the textured portion 14 or the bonding force can be weakened. This makes it possible to suppress a decrease in the performance and capacity of the battery cell 100.

[0182] Furthermore, the edges of the separation membrane 13 can be prevented from lifting or being damaged by torn or deformed portions at the boundary (below the first cutting line 113). This prevents shortening of the first electrode sheet 11 and the second electrode sheet 12. In addition, the amount of heat generated by the battery cell 100 can be reduced or the possibility of explosion can be significantly reduced.

[0183] Furthermore, since the forming portion 117 is formed by applying pressure to the forming portion 117a with the cut surface portion 115 removed from both sides in the width direction of the forming portion 117a, the uncut pieces of the forming portion 117a can be prevented from opening up at an angle due to the spring-back phenomenon. Also, when the forming portion 117a is applied with strong pressure using the press portion 230, the forming portion 117 (the uncut pieces of the forming portion 117a) can be superimposed on the cut surface portion 115 in a state of maximum flatness and close contact. As a result, the forming portion 117 and the cut surface portion 115 are welded in a state of surface contact with the current collection plates 130 and 140, which can significantly increase the weld cross-sectional area. In addition, as the weld cross-sectional area increases, the cross-sectional area of ​​the current path increases, which has the advantage of significantly reducing the resistance of the battery cell 100. This is because resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0184] The cut surface portion 115 is formed in a fan shape along the circumferential direction, centered on the core portion 112 of the electrode cell body portion 111. The apex of the cut surface portion 115 points toward the core portion 112. Because the cut surface portion 115 is formed in a fan shape, each forming portion 117 may be arranged radially between the multiple cut surface portions 115, centered on the core portion 112. In addition, the width of the forming portion 117 on the outer side may be the same as or wider than the width on the core portion 112 side, along the central angle of the fan-shaped cut surface portion 115.

[0185] The cut surface portion 115 can have a central angle (θ1) between 60° and 120°. The central angle (θ1) is the angle at which both sides open at the vertex of the sector. When the central angle (θ1) of the cut surface portion 115 is 90°, four cut surface portions 115 can be formed in a cross shape in the circumferential direction of the plain portion 15. When the central angle (θ1) of the cut surface portion 115 is 60°, six cut surface portions 115 can be formed in the circumferential direction of the plain portion 15. When the central angle (θ1) of the cut surface portion 115 is 120°, three cut surface portions 115 can be formed in the circumferential direction of the plain portion 15. In the present invention, the central angle (θ1) of the cut surface portion 115 is not limited to the above range. For example, the central angle may be 45°, 30°, or 180°.

[0186] The cut surface portion 115 can be formed by cutting a portion 16a that is spaced a certain distance (H) axially outward from the boundary portion 16 between the plain portion 15 and the textured portion 14. As a result, the second cutter portion 220 cuts the plain portion 15 at a position spaced away from the textured portion 14, thus preventing the active material coated on the textured portion 14 from detaching. Furthermore, even if the plain portion 15 is cut while slightly deformed, damage or deformation of the textured portion 14 can be prevented.

[0187] The central angle (θ1) of the cut surface portion 115 described above can be appropriately selected considering the diameter of the electrode cell body portion 111, the capacity of the battery cell 100, etc. For example, the larger the diameter of the electrode cell body portion 111, the closer the central angle of the cut surface portion 115 can be made to 60°. This is because, as the diameter of the electrode cell body portion 111 increases, increasing the cross-sectional area of ​​the current path is advantageous in preventing heat generation and ignition, so the central angle (θ1) of the cut surface portion 115 is reduced in order to increase the area of ​​the forming portion 117. Also, the closer the central angle (θ1) of the cut surface portion 115 can be made to 60°, the larger the capacity of the electrode cell body portion 111.

[0188] The forming portions 117 can be formed radially around the core portion 112 of the electrode cell body portion 111. When four forming portions 117 are formed in a cross shape, the central angle (θ1) of the cut surface portion 115 is 90°. When six forming portions 117 are formed radially around the core portion 112, the central angle (θ1) of the cut surface portion 115 is 60°. When three forming portions 117 are formed radially around the core portion 112, the central angle (θ1) of the cut surface portion 115 is 120°. Because the forming portions 117 are formed radially around the core portion 112, the current path can be uniformly distributed in the circumferential direction of the electrode cell body portion 111.

[0189] The forming portion 117 can be formed such that the forming portion 117a of the plain portion 15 lies radially outward from the electrode cell body portion 111. This prevents the forming portion 117 from obstructing the core portion 112 of the electrode cell body portion 111. The core portion 112 can also serve as a passage through which the electrolyte is injected, and in some cases, as a passage through which a welding rod is inserted. In this respect, it is preferable that the core portion 112 is open in the axial direction.

[0190] The outer end of the forming portion 117a is separated from the outer circumferential surface of the electrode cell body portion 111 by a certain distance (L3: see Figures 12 and 13) toward the center of the electrode cell body portion 111. Furthermore, the forming portion 117 has a form in which a certain section (L3) is removed toward the center from the outer circumferential surface of the electrode cell body portion 111. Since the outer portion 117b of the forming portion 117a is in a state where a certain section (L3) is removed by the third blade 222, even if the forming portion 117 is folded radially outward, it is possible to prevent it from protruding outward from the outer circumferential surface of the electrode cell body portion 111. This allows the electrode assembly 110 to be smoothly inserted into the battery can 120 during the manufacturing of the battery cell 100. It also prevents the forming portion 117 from getting caught in the battery can 120.

[0191] The axial height (W2) of the electrode cell body portion 111 of the forming portion 117a is formed to be less than the distance (L3) between the outer end of the forming portion 117a and the outer circumferential surface of the electrode cell body portion 111. This prevents the outermost edge of the forming portion 117 from protruding outward from the outer circumferential surface of the electrode cell body portion 111, even when the forming portion 117 is formed by laying the forming portion 117a on the outer circumferential surface side of the electrode cell body portion 111.

[0192] The forming portion 117 can be formed alongside the electrode cell body portion 111 in the radial direction. The forming portion 117 can be formed symmetrically around the core portion 112 of the electrode cell body portion 111. This allows the forming portion 117 to form current paths with approximately the same area in the radial direction of the electrode cell body portion 111.

[0193] A core portion 112 can be formed in the center of the electrode cell body portion 111. The core portion 112 is formed in a hollow shape that penetrates the center of the electrode cell body portion 111. The cross-section of the core portion 112 may be circular. Because the core portion 112 is formed in a hollow shape, after the electrode assembly 110 is placed in the battery can 120, an electrolyte injection machine (not shown) can inject the electrolyte through the core portion 112. This shortens the electrolyte injection time, thereby shortening the manufacturing time of the battery cell 100. In addition, when the electrolyte injection machine is inserted into the core portion 112, it is possible to prevent the electrode sheets 11, 12 and the separation membrane 13 near the core portion 112 from getting caught and tearing or being damaged.

[0194] The electrode cell body portion 111 can be formed in a cylindrical shape. This allows the outer surface of the electrode cell body portion 111 to be placed in close contact with the inner surface of the cylindrical battery can 120.

[0195] Next, we will describe the method for manufacturing a battery cell according to the present invention.

[0196] Figure 15 is a side view showing the press section according to the present invention in which the forming section is bent radially outward to form the forming section.

[0197] Referring to Figure 15, a separation membrane 13 is laminated between a sheet-like first electrode sheet 11 and a second electrode sheet 12 (S11). At this time, the structure in which the first electrode sheet 11, the second electrode sheet 12, and the separation membrane 13 are laminated is called an electrode laminate 10. In the electrode laminate 10, the plain portion 15 of the first electrode sheet 11 protrudes to one side in the width direction of the electrode laminate 10, and the plain portion 15 of the second electrode sheet 12 protrudes to the other side in the width direction of the electrode laminate 10.

[0198] The first electrode sheet 11, the second electrode sheet 12, and the separation membrane 13 are wound into a jelly roll (S12). At this time, the electrode stack 10 is wound onto a winding rod to form an electrode assembly 110, and the winding rod is separated from the electrode assembly 110. A hollow core portion 112 is formed in the center of the electrode assembly 110 where the winding rod was withdrawn. The core portion 112 is formed to penetrate the electrode assembly 110 in the axial direction. The more first electrode sheets 11, second electrode sheets 12, and separation membranes 13 are stacked on the electrode stack 10, the shorter the winding time and manufacturing time of the electrode assembly 110 can be.

[0199] The first cutter unit 210 moves axially along the battery cell 100 and radially cuts the blank portions 15 of the first electrode sheet 11 and the second electrode sheet 12 (S13). A first cutting line 113 is formed in the radially cut portions of the blank portion 15. At this time, the portion to be cut 115a and the portion to be formed 117a are separated with respect to the first cutting line 113. The portion to be cut 115a and the portion to be formed 117a are arranged alternately along the circumferential direction of the electrode cell body 111. At this time, the portion to be cut 115a and the portion to be formed 117a maintain their upright position along the axial direction of the electrode cell body 111.

[0200] The second cutter section 220 moves radially over the electrode cell body section 111, forming a second cutting line 16a in the circumferential direction on the plain section 15 that has been wound in the circumferential direction. The second cutting line 16a is connected to the first cutting line 113, and the outer portion 117b and the portion 115a of the forming section 117a, which are surrounded by the first cutting line 113 and the second cutting line 16a, are cut off to form a cut surface portion 115 on the plain section 15 of the electrode assembly 110 (S14).

[0201] The radial length (L2-L3) of the electrode cell body portion 111 in the forming portion 117a is formed to be shorter than the length (L2) of the first cutting line 113. In this case, the forming portion 117a has a shape in which a certain section (L3) is removed from the outer circumferential surface of the electrode cell body portion 111 toward the center. This prevents the forming portion 117a from protruding outward from the outer circumferential surface of the electrode cell body portion 111 even when it is folded radially outward.

[0202] The axial height (W2) of the electrode cell body portion 111 of the forming portion 117a is formed to be less than the distance (L3) between the outer end of the forming portion 117a and the outer circumferential surface of the electrode cell body portion 111. As a result, when the forming portion 117a is laid on the outer circumferential surface side of the electrode cell body portion 111 and the forming portion 117 is formed, the outermost edge of the forming portion 117 lies on the portion of the forming portion 117a that has been removed.

[0203] The press section 230 presses the forming portion 117a of the blank portion 15 radially outward from the electrode cell body portion 111, thereby forming the forming portion 117 (S15).

[0204] In this case, the multiple forming sections 117 may be formed by having multiple non-cut pieces constituting the forming section 117a overlapping in a continuous manner. This allows the forming sections 117 to be formed at a slight angle in the axial direction of the electrode cell body section 111.

[0205] Since the cut surface portion 115 is laser-welded to the current collection plates 130 and 140 while in line contact with them, the cut surface portion 115 can hardly increase the current path. On the other hand, since the forming portion 117 is formed with the forming portion 117a laid radially outward, the forming portion 117 covers the gap between the plain portions 15 separated by the thickness of the separation film 13. Since these forming portions 117 are welded in surface contact with the current collection plates 130 and 140, the larger the area of ​​the forming portion 117, the more the current path between the electrode assembly 110 and the current collection plates 130 and 140 can relatively increase. Since these forming portions 117 increase the current path by the combined area of ​​the gap between the plain portions 15, even when applied to a large-capacity battery cell 100, it is possible to suppress the increase in heat generation of the battery cell 100 and reduce the possibility of ignition.

[0206] After the cutting portion 115a and the forming portion 117a in the plain portion 15 are separated from each other, the outer portion 117b of the cutting portion 115a and the forming portion 117a is cut to form the cut surface portion 115, and the forming portion 117a is pressed and laid down to form the forming portion 117. This prevents the boundary between the forming portion 117 and the cut surface portion 115 from tearing or deforming irregularly when the forming portion 117a is pressed to form the forming portion 117.

[0207] Furthermore, it is possible to prevent the edges of the separation membrane 13 from lifting or being damaged due to tears or deformation at the boundary. This prevents shortening of the first electrode sheet 11 and the second electrode sheet 12. In addition, it is possible to reduce the amount of heat generated by the battery cell 100 or significantly reduce the possibility of explosion.

[0208] The cut surface portion 115 can be formed in a fan shape along the circumferential direction, centered on the core portion 112 of the electrode cell body portion 111. The apex of the cut surface portion 115 points toward the core portion 112. Because the cut surface portion 115 is formed in a fan shape, each forming portion 117 may be arranged radially between multiple cut surface portions 115, centered on the core portion 112.

[0209] The cut surface portion 115 can have a central angle (θ1) of 60° to 120°. For example, if the central angle (θ1) of the cut surface portion 115 is 90°, four cut surfaces 115 can be formed in a cross shape in the circumferential direction of the plain portion 15. If the central angle (θ1) of the cut surface portion 115 is 60°, six cut surfaces can be formed in the circumferential direction of the plain portion 15. If the central angle (θ1) of the cut surface portion 115 is 120°, three cut surfaces can be formed in the circumferential direction of the plain portion 15.

[0210] The cut surface portion 115 can be formed by cutting a portion (second cutting line 16a) that is a certain distance axially outward from the boundary portion 16 between the plain portion 15 and the textured portion 14. As a result, the second cutter portion 220 cuts the plain portion 15 at a position 16a that is separated from the textured portion 14, thus preventing the active material coated on the textured portion 14 from detaching. Furthermore, even if the plain portion 15 is cut while slightly deformed, damage or deformation of the textured portion 14 can be prevented.

[0211] The forming portions 117 can be formed radially around the core portion 112 of the electrode cell body portion 111. When four forming portions 117 are formed in a cross shape, the central angle (θ1) of the cut surface portion 115 is 90°. When six forming portions 117 are formed radially around the core portion 112, the central angle (θ1) of the cut surface portion 115 is 60°. When three forming portions 117 are formed radially around the core portion 112, the central angle (θ1) of the cut surface portion 115 is 120°. Because the forming portions 117 are formed radially around the core portion 112, the current path can be uniformly distributed in the circumferential direction of the electrode cell body portion 111.

[0212] The forming portion 117 can be formed such that the forming portion 117a of the blank portion 15 lies horizontally on the radially outward side of the electrode cell body portion 111. This prevents the forming portion 117 from protruding outward from the outer surface of the electrode cell body portion 111, allowing the electrode assembly 110 to be smoothly inserted into the battery can 120 during the manufacturing of the battery cell 100. It also prevents the forming portion 117 from getting caught in the battery can 120.

[0213] The forming portion 117 can be formed along the radial direction of the electrode cell body portion 111. The forming portion 117 can be formed symmetrically around the core portion 112 of the electrode cell body portion 111.

[0214] The first cutter unit 210 cuts the plain section 15 while vibrating due to the first vibration generating unit 213. The first vibration generating unit 213 may include an ultrasonic transducer. Because the first cutter unit 210 vibrates while cutting the plain section 15, the cutting performance and cutting speed of the plain section 15 can be improved.

[0215] The second cutter section 220 cuts the plain section 15 while vibrating due to the second vibration generating section 223. The second vibration generating section 223 may include an ultrasonic transducer. Because the second cutter section 220 vibrates while cutting the plain section 15, the cutting performance and cutting speed of the plain section 15 may be improved.

[0216] In the processing of the cut surface described above, it is preferable to perform the processing with the first cutter first, followed by the processing with the second cutter.

[0217] We will now describe a battery cell manufactured using the electrode assembly described above.

[0218] Figure 17 is a cross-sectional view showing the electrode assembly according to the present invention.

[0219] Referring to Figure 17, the battery cell 100 according to the present invention includes an electrode assembly 110, a battery can 120, a sealing cap portion 150, and a first current collector plate 130.

[0220] Since the electrode assembly 110 is substantially the same as described above, its explanation will be omitted.

[0221] The electrode assembly 110 is housed inside the battery casing 120. The battery casing 120 is electrically connected to either the first electrode sheet 11 or the second electrode sheet 12 to exhibit a first polarity. The battery casing 120 can be formed from a conductive material so that current can flow through it. For example, the battery casing 120 can be manufactured from materials including stainless steel and aluminum. The battery casing 120 can be formed in a cylindrical shape with an open end on one side.

[0222] The sealing cap portion 150 seals the open end of the battery can 120. The sealing cap portion 150 is installed to insulate it from the battery can 120. The sealing cap portion 150 prevents external foreign matter and moisture from penetrating into the inside of the battery can 120.

[0223] The first current collector plate 130 has a second polarity, which means it is electrically connected to the other one of the first electrode sheet 11 and the second electrode sheet 12. The first current collector plate 130 may be positioned between the electrode assembly 110 and the sealing cap portion 150. The first current collector plate 130 is electrically connected to the sealing cap portion 150. The first current collector plate 130 can be welded to the other blank portion 15 of the first electrode sheet 11 and the second electrode sheet 12. In this case, the forming portion 117 of the blank portion 15 can be welded in surface contact with the first current collector plate 130, and the cut surface portion 115 of the blank portion 15 can be welded in line contact with the first current collector plate 130. This increases the weld cross-sectional area between the blank portion 15 and the first current collector plate 130, which increases the cross-sectional area of ​​the current path and significantly reduces the electrical resistance of the battery cell 100. Furthermore, the amount of heat generated by the battery cell 100 can be reduced, thereby lowering the possibility of the battery cell 100 catching fire.

[0224] The first electrode sheet 11 may be a negative electrode sheet, and the second electrode sheet 12 may be a positive electrode sheet. Alternatively, the first electrode sheet 11 may be a positive electrode sheet, and the second electrode sheet 12 may be a negative electrode sheet.

[0225] The electrolyte is injected into the battery can 120 described above via the core portion 112 of the electrode assembly 110.

[0226] The electrolyte is A + B - It may also be a salt having a structure like the following. Here, A + Li + kaNa + , K + It contains alkali metal cations such as these, and ions consisting of combinations thereof. And B - is, F - Cl - , Br - , I - NO3 - , N(CN)2 - BF4 - ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - BF2C2O4 - BC4O8 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - , C4F9SO3 - CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2) 2CH - (SF5)3C - (CF3SO2)3C- CF3(CF2)7SO3 - CF3CO2 - CH3CO2 - SCN - , and (CF3CF2SO2)2N - It contains one or more anions selected from the group consisting of the following.

[0227] The electrolyte can also be used dissolved in an organic solvent. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), gamma-butyrolactone, or mixtures thereof.

[0228] The sealing cap portion 150 covers the first current collector plate 130 and may further include an insulator 157 whose edge is interposed between the inner circumferential surface of the support portion 122 and the first current collector plate 130. The insulator 157 electrically insulates the sealing cap portion 150 from the battery can 120.

[0229] The insulator 157 may be made of an insulating polymer resin. For example, the insulator 157 may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0230] The sealed cap portion 150 includes a cap plate 151 that is installed to block the open end of the battery can 120. The cap plate 151 can be formed in an overall disc shape. An external terminal 152 is formed at the center of the cap plate 151, protruding outward (towards the upper side in Figure 17).

[0231] The sealed cap section 150 includes a vent plate 153 positioned below the cap plate 151. The vent plate 153 ruptures when the internal pressure of the battery can 120 exceeds a set pressure. These vent plates 153 prevent the battery cells 100 from exploding.

[0232] The vent plate 153 and the first current collector plate 130 are electrically connected by the lead portion 155. The vent plate 153 also contacts the cap plate 151, forming part of the current path.

[0233] A support portion 122 is formed on the lower side of the open end of the battery can 120, recessing into the inside of the battery can 120. A vent plate 153 and a cap plate 151 are stacked on top of the support portion 122.

[0234] Insulators 157 are interposed on the inner surface of the support portion 122 and around the vent plate 153 and cap plate 151. The insulators 157 cover the first current collector plate 130, and their ends are interposed between the inner circumferential surface of the support portion 122 and the first current collector plate 130. These insulators 157 constitute a part of the sealed cap portion 150.

[0235] A clamping portion 123 is formed at the open end of the battery can 120 to pressurize the cap plate 151 and the insulator 157. The clamping portion 123 bends the open end of the battery can 120 inward, sealing the space between the cap plate 151 and the open end of the battery can 120. The support portion 122 allows the clamping portion 123 to press and fix the first current collector plate 130 and the vent plate 153 together, thereby restricting the movement of the first current collector plate 130 and the vent plate 153, which can improve the assembly stability of the battery cell 100. It can also prevent the airtight seal of the battery can 120 from being leaked due to external impact.

[0236] Either the first electrode sheet 11 or the second electrode sheet 12 of the battery can 120 can be electrically connected via the second current collector plate 140. In this case, the second current collector plate 140 can be welded to a blank portion 15 formed on either the first electrode sheet 11 or the second electrode sheet 12. The cut surface portion 115 and the forming portion 117 of the blank portion 15 can be welded to the second current collector plate 140 by laser. This increases the weld cross-sectional area between the blank portion 15 and the second current collector plate 140, thereby increasing the cross-sectional area of ​​the current path and significantly reducing the electrical resistance of the battery cell 100. It also reduces the amount of heat generated by the battery cell 100, lowering the possibility of the battery cell 100 catching fire.

[0237] Furthermore, it goes without saying that the plain portion 15 formed on either the first electrode sheet 11 or the second electrode sheet 12 can be directly welded to the inner surface of the battery can 120.

[0238] Figure 18 is a perspective view showing the electrode assembly according to the present invention housed in a pack housing.

[0239] Referring to Figure 18, the battery pack according to an embodiment of the present invention includes an assembly of electrically connected cylindrical battery cells 100 and a pack housing 101 that houses them. The cylindrical battery cells 100 may be any of the battery cells 100 according to the embodiments described above. For convenience of illustration, the drawings omit the depiction of components such as busbars (not shown), cooling units (not shown), and external terminals (not shown) for the electrical connection of the cylindrical battery cells 100.

[0240] The battery pack can be mounted on the vehicle 300. The vehicle 300 is an example and may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes four-wheeled vehicles and two-wheeled vehicles.

[0241] Figure 19 is a diagram illustrating a vehicle including a battery pack according to the present invention.

[0242] Referring to Figure 19, a vehicle 300 according to one embodiment of the present invention includes a battery cell 100 according to one embodiment of the present invention. The vehicle is powered and operated by the battery cell 100 according to one embodiment of the present invention.

[0243] As described above, the present invention has been explained with reference to the illustrative drawings. However, the present invention is not limited by the embodiments and drawings disclosed herein, and it is obvious to an ordinary person skilled in the art that various modifications can be made within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described and explained while embodiments of the present invention have been described above, it is natural to acknowledge that the effects that can be predicted by such configuration should also be recognized. [Explanation of Symbols]

[0244] 10 Electrode Stack 11. First electrode sheet 12. Second electrode sheet 13 Separation membrane 14 Landed part 15 Plain section 16 Boundary 16a Second cutting line 100 battery cells 101 Pack Housing 110 Electrode assembly 111 Electrode cell body 112 Core section 113 First Cutting Line 115 Cut section 115a Section to be cut 117 Forming section 117a Forming planned section 117b Outer part of the area to be formed 120 Battery Can 121 Battery can body 122 Supporters Department 123 Clamping section 130 First current collection plate 132 Center hole 140 Second current collection plate 150 Sealing cap section 151 Cap Plate 152 External terminals 153 Vent Plate 155 Lead section 157 Insulators 210 First cutter section 211 First Blade 211a First blade 213 First vibration generating section 215 1st communication hole 220 Second Cutter Section 221 Second Blade 221a One side of the second blade 221b Other side of the second blade 222 Third Blade 222a One side of the third blade 222b Other side of the third blade 223 Second vibration generating section 230 Press Department 300 vehicles

Claims

1. A cutting device for cutting at least a portion of the blank portion (15) of an electrode cell body portion (111) which is wound up in a laminated state, and has a blank portion (15) at the widthwise end of at least one of the sheets of the first electrode sheet (11) and the second electrode sheet (12) where the active material layer is not coated, the device for cutting at least a portion of the blank portion (15) of the electrode assembly (110), A first cutter section (210) moves axially along the electrode assembly (110) and forms a first cutting line (113) in the axial direction on the plain section (15) that extends axially, and separates the section to be cut (115a) and the section to be formed (117a) with respect to the first cutting line (113), and A second cutter section (220) forms a cut surface (115) on the plain portion (15) of the electrode assembly (110) by forming a second cutting line (16a) in the circumferential direction on the plain portion (15) that is wound in the circumferential direction while moving radially on the electrode assembly (110), and by cutting off the outer portion (117b) of the forming target portion (117a) and the target portion (115a) surrounded by the first cutting line (113) and the second cutting line (16a) such that the second cutting line (16a) is connected to the first cutting line (113), thereby forming a cut surface (115) on the plain portion (15) of the electrode assembly (110). including, Cutting device.

2. The first cutter section (210) includes a plurality of first blades (211) arranged radially and extending in the axial direction. The cutting device according to claim 1.

3. The first cutter section (210) further includes a first vibration generating section (213). The cutting device according to claim 1.

4. The second cutter section (220) is A second blade (221) is formed in a triangular shape with blades (221a, 221b) on both sides, so as to cut the portion to be cut (115a) in a fan shape, and A third blade (222) is connected to one side of the second blade (221) and has blades (222a, 222b) formed on it to cut the outer portion (117b) of the forming target portion (117a). including, A cutting device according to any one of claims 1 to 3.

5. The third blade (222) is formed in a triangular shape with blades (222a, 222b) on both sides. The cutting device according to claim 4.

6. The side cutting edge (221a) of the second blade (221) is formed to be longer than the length of the first cutting line (113), The other blade (221b) of the second blade (221) is formed to be shorter than the length of the first cutting line (113), The third blade (222) is connected to the outer end of the other blade (221b) of the second blade (221). The cutting device according to claim 4.

7. One side cutting edge (222a) of the third blade (222) is formed to have the same length as the width of the forming portion (117a), The cutting device according to claim 4.

8. The length of the other side blade (222b) of the third blade (222) is formed to be less than or equal to the length of the one side blade (222a) of the third blade (222). The cutting device according to claim 4.

9. The second cutter section (220) further includes a second vibration generating section (223). The cutting device according to claim 1.

10. A cutting device according to claim 1, and The plain portion (15) presses and lays down the uncut forming portion (117a) to form the forming portion (117) with a press portion (230). An electrode assembly processing apparatus, including, The pressing section (230) is moved radially outward from the electrode cell body section (111) to lay the forming portion (117a) of the blank section (15) radially outward from the electrode cell body section (111). Electrode assembly processing equipment.

11. A step of manufacturing an electrode cell body (111) by laminating and winding a sheet-like first electrode sheet (11), a second electrode sheet (12), and a separation membrane (13), The first cutter section (210) moves in the axial direction of the electrode cell body section (111) and forms a first cutting line (113) in the axial direction on the blank sections (15) of the first electrode sheet (11) and the second electrode sheet (12), and separates the section to be cut (115a) and the section to be formed (117a) with respect to the first cutting line (113). The second cutter section (220) moves radially along the electrode cell body section (111) and forms a second cutting line (16a) in the circumferential direction on the plain section (15) that has been wound in the circumferential direction, and the second cutting line (16a) is connected to the first cutting line (113), thereby cutting off the outer portion (117b) of the forming target section (117a) surrounded by the first cutting line (113) and the second cutting line (16a), and the target section (115a), thereby forming a cut surface section (115) on the plain section (15) of the electrode assembly (110), and The pressing section (230) presses the forming portion (117a) of the blank portion (15) radially outward from the electrode cell body portion (111) to form the forming portion (117). including, A method for manufacturing a battery cell (100).

12. The radial length of the electrode cell body portion (111) of the forming portion (117a) is formed to be shorter than the length of the first cutting line (113). A method for manufacturing a battery cell (100) according to claim 11.

13. The axial height of the electrode cell body portion (111) of the forming portion (117a) is formed to be less than the distance between the outer end of the forming portion (117a) and the outer circumferential surface of the electrode cell body portion (111). A method for manufacturing a battery cell (100) according to claim 11.

14. The cut surface portion (115) is formed in a fan shape along the circumferential direction, centered on the core portion (112) of the electrode cell body portion (111). A method for manufacturing a battery cell (100) according to any one of claims 11 to 13.

15. The aforementioned cut surface portion (115) has a central angle of 60° to 120°. A method for manufacturing a battery cell (100) according to claim 14.

16. The forming portion (117) is formed radially around the core portion (112) of the electrode cell body portion (111), A method for manufacturing a battery cell (100) according to claim 11.

17. The forming portion (117) is formed such that the forming portion (117a) of the blank portion (15) lies horizontally outside the electrode cell body portion (111). A method for manufacturing a battery cell (100) according to claim 11.

18. The forming portion (117) is formed along the radial direction of the electrode cell body portion (111), A method for manufacturing a battery cell (100) according to claim 11.

19. The cut surface portion (115) is formed by cutting a portion that is a certain distance outward in the axial direction from the boundary portion (16) between the plain portion (15) and the textured portion (14). A method for manufacturing a battery cell (100) according to claim 11.

20. The first cutter section (210) vibrates due to the first vibration generating section (213) and cuts the plain section (15). A method for manufacturing a battery cell (100) according to claim 11.

21. The second cutter section (220) vibrates due to the second vibration generating section (223) and cuts the plain section (15). A method for manufacturing a battery cell (100) according to claim 11.

22. An electrode cell body portion (111) is formed in which a separation membrane (13) is laminated between a sheet-like first electrode sheet (11) and a second electrode sheet (12), and the first electrode sheet (11), the second electrode sheet (12), and the separation membrane (13) are wound into a jelly roll, and plain portions (15) where the active material layer is not coated are formed at the widthwise ends of the first electrode sheet (11) and the second electrode sheet (12). A plurality of cut surfaces (115) are defined by a first cutting line (113) formed axially in the plain portion (15) and a second cutting line (16a) formed circumferentially connected to the first cutting line (113), and are arranged along the circumferential direction with respect to the core portion (112) of the electrode cell body portion (111), and A plurality of forming portions (117) are arranged between the plurality of cut surface portions (115) in the circumferential direction, and are defined by the fact that the portion of the plain portion (15) between a pair of adjacent first cut lines (113) in the circumferential direction is formed to be inclined with respect to the axial direction or to be formed to be flat, including, Electrode assembly (110).

23. The cut surface portion (115) is formed in a fan shape along the circumferential direction, centered on the core portion (112) of the electrode cell body portion (111). The electrode assembly (110) according to claim 22.

24. The aforementioned cut surface portion (115) has a central angle of 30° to 180°. The electrode assembly (110) according to claim 23.

25. The second cutting line (16a) defining the cut surface portion (115) is formed at a portion a certain distance outward in the axial direction from the boundary portion (16) between the plain portion (15) and the textured portion (14). The electrode assembly (110) according to claim 22.

26. The plain portion (15) constituting the forming portion (117) is separated by a certain distance (L3) from the outer circumferential surface of the electrode cell body portion (111) toward the central side of the electrode cell body portion (111). The electrode assembly (110) according to claim 22.

27. The axial length (W2) of the plain portion (15) that constitutes the forming portion (117) is formed to be less than the certain distance (L3). The electrode assembly (110) according to claim 26.

28. The forming portion (117) is formed radially around the core portion (112) of the electrode cell body portion (111), The electrode assembly (110) according to claim 22.

29. The forming portion (117) is formed such that the plain portion (15) constituting the forming portion (117) lies horizontally on the radially outward side of the electrode cell body portion (111). The electrode assembly (110) according to claim 22.

30. The forming portion (117) is formed in which a certain section is removed from the outer circumferential surface of the electrode cell body portion (111) toward the center. The electrode assembly (110) according to claim 29.

31. The core portion (112) is formed in a hollow shape that penetrates the center of the electrode cell body portion (111), and the forming portion (117) is laid horizontally radially outward so as not to obstruct the core portion (112) in the axial direction. The electrode assembly (110) according to claim 29.

32. Electrode assembly (110) according to any one of claims 22 to 31, A battery can (120) containing the electrode assembly (110) and electrically connected to either the first electrode sheet (11) or the second electrode sheet (12), which has a first polarity, A sealing cap portion (150) that seals the open end of the battery can (120), and A first current collector plate (130) having a second polarity is electrically connected to the other of the first electrode sheet (11) and the second electrode sheet (12), including, Battery cell (100).

33. The first current collector plate (130) is welded to the forming portion (117). The battery cell (100) according to claim 32.

34. A battery cell (100) according to claim 33, comprising at least one of the following: Battery pack.

35. A battery pack comprising at least one of the battery packs described in claim 34, vehicle.

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