Electrode assembly, battery cell, battery cell processing device, battery pack including the same, and vehicle

Abstract

The present invention discloses an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and a vehicle including the same. The present invention provides an electrode assembly 110 including an electrode cell body part 111 in which a separator 13 is laminated between a sheet-like first electrode sheet 11 and a second electrode sheet 12, the first electrode sheet 11, the second electrode sheet 12, and the separator 13 are wound up in a jelly roll shape, and an uncoated part 15 is formed at a widthwise end of the first electrode sheet 11 and the second electrode sheet 12 where an active material layer is not coated; a plurality of cut surface parts 115 formed by cutting a part of the uncoated part 15 in a circumferential direction around a core part 112 of the electrode cell body part 111; and a plurality of forming parts 117 disposed between the cut surface parts 115 and formed by pressing and laying a non-cut part 117a of the uncoated part 15.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0046801 filed on April 9, 2021, and Korean Patent Application No. 10-2022-0040634 filed on March 31, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an electrode assembly, a device for cutting an uncoated portion of the electrode assembly, a folding device, a battery cell including the electrode assembly, and a battery pack and a vehicle including the battery cell. [Background technology]

[0003] In general, secondary batteries contain a positive electrode, a negative electrode, and an electrolyte, and generate electrical energy through a chemical reaction. Secondary batteries, which are easily applicable to a wide range of products and have electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are powered by electrical sources.

[0004] These secondary batteries have the primary advantage of dramatically reducing the use of fossil fuels and producing no by-products associated with energy consumption. For this reason, secondary batteries are attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0005] Currently, widely used types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of these unit secondary battery cells, i.e., unit battery cells 100, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting multiple battery cells in series. Alternatively, a battery pack may be configured by connecting multiple battery cells 100 in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack and the form of electrical connection can be variously set depending on the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, known types of unit secondary battery cells include cylindrical, prismatic, and pouch-type battery cells. In the case of a cylindrical battery cell, a separator, which is an insulator, is interposed between a positive electrode and a negative electrode, and the separator is wound up to form a jelly-roll-like electrode assembly. This is then inserted into a battery can to form a battery. Strip-shaped electrode tabs may be connected to the uncoated portions of the positive and negative electrodes. The electrode tabs electrically connect the electrode assembly to electrode terminals exposed to the outside. For reference, the positive electrode terminal is a cap plate of a sealing body that seals the opening of the battery can, and the negative electrode terminal is the battery can. However, conventional cylindrical battery cells with this structure have problems such as high resistance, excessive heat generation, and poor current collection efficiency due to current concentration at the strip-shaped electrode tabs connected to the positive and / or negative uncoated portions. That is, the cross-sectional area of ​​the electrode tabs may be rapidly reduced, causing a bottleneck in current flow.

[0007] Resistance and heat generation are not major issues for small cylindrical battery cells with form factors such as 18650 and 21700. However, when the form factor of cylindrical battery cells is increased to apply them to electric vehicles, a large amount of heat is generated around the electrode tabs during fast charging, which can cause the cylindrical battery cell to catch fire.

[0008] To solve these problems, a cylindrical battery cell (so-called tab-less cylindrical battery cell) has been proposed, which has a structure in which positive and negative uncoated areas are located at the top and bottom of a jelly-roll-shaped electrode assembly, respectively, and current collecting plates are welded to these uncoated areas, thereby improving current collection efficiency.

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

[0010] The electrode assembly is fabricated by stacking the first and second electrode sheets together with two separators and then winding them in one direction, with the uncoated portions of the first and second electrode sheets facing in opposite directions.

[0011] After the winding process, the uncoated portions of the first and second electrode sheets are folded toward the core, and then current collecting plates are welded to the uncoated portions.

[0012] The positive and negative uncoated regions do not have separate electrode tabs attached, and the current collecting plates are connected to external electrode terminals, forming a current path with a large cross-sectional area along the winding axis of the electrode assembly, which has the advantage of lowering the resistance of the battery cell, since resistance is inversely proportional to the cross-sectional area of ​​the path through which current flows.

[0013] In a table-less cylindrical battery cell, in order to improve the welding characteristics between the plain portion and the current collecting plate, it is necessary to apply a strong pressure to the welding point of the plain portion and bend the plain portion as flat as possible.

[0014] However, when the welding point of the non-coating portion is bent, the pattern of the non-coating portion may become irregularly distorted and deformed. In this case, the deformed portion may come into contact with the electrode plate of the opposite polarity, causing an internal short circuit or microcracks in the non-coating portion. Furthermore, as the non-coating portion adjacent to the core of the electrode assembly is bent, it may block all or a significant portion of the cavity in the core of the electrode assembly. This causes problems during the electrolyte injection process. That is, the cavity in the core of the electrode assembly serves as a passage through which the electrolyte is injected. However, if this passage is blocked, it is difficult to inject the electrolyte. Furthermore, when the electrolyte injector is inserted into the cavity, it may interfere with the non-coating portion near the core, resulting in tearing of the non-coating portion.

[0015] In addition, the bent portion of the plain area where the current collecting plate is welded must be overlapped in multiple places without any gaps. This ensures sufficient welding strength and prevents the laser from penetrating into the electrode assembly and damaging the separator or active material, even when using cutting-edge technology such as laser welding.

[0016] Korean Patent Publication No. 2022-0023100 (published on March 2, 2022) discloses a cylindrical secondary battery with an improved current collection structure. Cylindrical secondary batteries have a problem in that the current collecting plate is welded to the edge of the uncoated portion in a line contact state, reducing the cross-sectional area of ​​the weld between the current collecting plate and the uncoated portion due to the gap between the uncoated portion. This increases electrical resistance in the weld cross-sectional area, which is the path of current, increasing the amount of heat generated by the battery cell and potentially increasing the risk of fire.

[0017] Korean Patent Publication No. 2016-0110610 (published on September 22, 2016) discloses a secondary battery and a cylindrical lithium secondary battery. These secondary batteries are configured such that a first current collecting plate is electrically connected to a first uncoated portion so that it directly contacts the first uncoated portion, and a second current collecting plate is electrically connected to a second uncoated portion so that it directly contacts the second uncoated portion. This also has the problem that the contact cross-sectional area between the current collecting plate and the uncoated portion is reduced due to gaps between the uncoated portions because the first and second current collecting plates are connected to the ends of the first and second uncoated portions in a line contact state. There is a limit to how much the contact cross-sectional area can be increased. Summary of the Invention [Problem to be solved by the invention]

[0018] The present invention has been devised to solve the above-mentioned problems, and aims to provide an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and vehicle including the same, which can increase the welding cross-sectional area between the electrode assembly and the current collecting plate to expand the current path.

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

[0020] Another object of the present invention is to provide an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and vehicle including the same, which can prevent the boundary between the forming portion and the cutting surface portion from breaking or being irregularly distorted and deformed.

[0021] Another object of the present invention is to provide an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and vehicle including the same, which can reduce the amount of heat generated by the battery cell or significantly reduce the possibility of explosion.

[0022] The technical object of the present invention is not limited to the above-mentioned objects, and other unmentioned objects and advantages of the present invention can be understood from the following description and can be more clearly understood from the embodiments of the present invention. Also, it is clear that the objects and advantages of the present invention can be achieved by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0023] To solve the above-mentioned problems, the present invention can be applied to an electrode assembly including a jelly-roll-shaped electrode cell body part in which first and second electrode sheets having different polarities and a separator for insulation between them are stacked and wound up.

[0024] The sheets can be stacked in the order of the first electrode sheet, the separator, the second electrode sheet, and the separator.

[0025] The winding may be performed along the length of the stacked sheets, and the axial length of the jelly-roll-shaped electrode cell body portion formed thereby may correspond to the width of the stacked sheets.

[0026] At least one of the first electrode sheet and the second electrode sheet has a plain portion at a widthwise end portion where the active material layer is not coated. Thus, the plain portion is provided at an axial end portion of the electrode cell body portion. The plain portion may be provided on either side of the axial end portion of the electrode cell body portion or on both sides.

[0027] The uncoated portion of the electrode cell body of the electrode assembly has a plurality of cut surface portions formed by cutting away portions of the uncoated portion, and the uncoated portion remaining after the cutting away portions constitutes an uncut portion.

[0028] The cut surface portions are arranged in a plurality along a circumferential direction around the core portion, and the non-cut portion is arranged between two cut surface portions adjacent to each other in the circumferential direction.

[0029] The electrode assembly includes a plurality of forming portions formed by bending the non-cut portions.

[0030] The cut surface portion may be formed in a fan shape along a circumferential direction with the core portion of the electrode cell body portion as the center.

[0031] The cut surface may have a central angle of 30° to 180°. More specifically, the cut surface may have a central angle of 45° to 180°, and more preferably, the cut surface may have a central angle of 60° to 120°.

[0032] The cut surface portion may be formed by cutting a portion spaced a certain distance outward in the axial direction at the boundary between the non-coated portion and the maintaining portion. In other words, it can be said that the cut surface portion cuts the non-coated portion of the maintaining portion and the non-coated portion.

[0033] The forming portion may be formed radially from a core portion of the electrode cell body portion as a center.

[0034] The forming portion may be formed by bending the non-cut portion in a radial direction of the electrode cell body portion and laying it down. The non-cut portion may be laid down on a core portion side.

[0035] The formed portions may be formed uniformly in the radial direction of the electrode cell body portion.

[0036] The electrode cell body portion may be formed in a cylindrical shape.

[0037] The core portion may be formed in a hollow shape that penetrates through the center of the electrode cell body portion.

[0038] When the uncut portion is laid on the core portion, in order to prevent the core portion from being blocked by the bent uncut portion, the uncoated portion disposed closer to the core portion of the electrode assembly between the core portion and the outer periphery may be removed. The removal of the uncoated portion may be performed prior to the winding process.

[0039] That is, the non-coating portion may be removed from a predetermined section adjacent to the core portion in the winding direction.

[0040] When the sheet laminate with the core-side uncoated portion removed is wound up, the uncoated portion near the core is already removed before the cut surface portion is formed. That is, the uncut portion is not provided on the core side. Therefore, even if the uncut portion is bent toward the core, the laid-down forming portion does not block the core portion of the electrode assembly.

[0041] The present invention provides a battery cell including the electrode assembly.

[0042] The battery cell includes a battery can that houses the electrode assembly, is electrically connected to either the first electrode sheet or the second electrode sheet, and has a first polarity; a sealing cap portion that seals an open end of the battery can; and a first current collecting plate that is electrically connected to the other of the first electrode sheet and the second electrode sheet and has a second polarity.

[0043] The first current collecting plate may be fixed to and electrically connected to a forming portion of the electrode assembly by welding or the like.

[0044] Either the first electrode sheet or the second electrode sheet may be directly connected to the battery can or may be connected via a second current collecting plate.

[0045] The battery can may include a supporter portion further protruding radially inward from an inner periphery of the battery can, and the supporter portion may support the sealing cap portion.

[0046] The battery cell may further include an insulator to prevent short circuits of opposite polarities.

[0047] The insulator may be interposed between the battery can and the sealing cap to provide insulation therebetween. More specifically, the insulator may be interposed between the outer circumferential surface of the sealing cap and the inner circumferential surface of the battery can, and may be interposed between the supporter and the sealing cap.

[0048] The insulator may be interposed between the battery can and the first current collecting plate to provide insulation therebetween. For example, the insulator may be interposed between the first current collecting plate and the support portion.

[0049] The present invention provides a battery pack including at least one of the battery cells.

[0050] The present invention provides a vehicle including at least one battery pack as described above.

[0051] The present invention provides a cutting device for cutting the uncoated portion provided at the axial end of the electrode cell body of the electrode assembly.

[0052] The cutting device includes a first cutter unit that moves in the axial direction of the electrode assembly to form a first cutting line in the axial direction on the uncoated portion, and a second cutter unit that moves in the radial direction of the electrode assembly to form a second cutting line in the circumferential direction on the uncoated portion.

[0053] The second cutter forms a second cutting line that cuts a portion of the non-coating portion wound in the circumferential direction, and forms a cutting line such that the second cutting line is connected to the first cutting line.

[0054] The first cutting line and the second cutting line are connected, so that the uncoated portion surrounded by the first cutting line and the second cutting line can be cut out.

[0055] The present invention can provide a processing device including the cutting device and a press unit that bends the uncut portion that remains after being cut off by the cutting device.

[0056] The press unit presses and lays down the uncut portion of the plain portion to form a formed portion.

[0057] The non-cut portion may be radially pressed by the press portion, whereby the non-cut portion may be bent at a portion corresponding to the second cutting line and laid in the radial direction.

[0058] The first cutter unit may include a plurality of first blades arranged radially on the first cutter unit.

[0059] The first blade may extend in the axial direction and have a cutting edge formed at its axial tip.

[0060] The first cutter may further include a first vibration generating unit, which may generate minute vibrations.

[0061] The second cutter may be formed in a triangular shape so as to cut a part of the uncoated portion into a fan shape.

[0062] Two sides of the tip of the second cutter section may be formed with blades.

[0063] The second cutter unit may further include a second vibration generating unit that generates minute vibrations.

[0064] The press unit may move in the radial direction of the electrode cell body unit to lay the uncut portion of the uncoated portion on the core portion side of the electrode cell body unit.

[0065] The present invention provides a method for manufacturing the above-mentioned battery cell.

[0066] The method for manufacturing such a battery cell includes the steps of laminating a first electrode sheet, a second electrode sheet, and a separator, and winding the laminate to form an electrode assembly.

[0067] Accordingly, the electrode assembly may include an electrode cell body portion in which the electrode sheet and the separator are wound together.

[0068] The electrode cell body portion may be cylindrical.

[0069] The electrode cell body may include a hollow core.

[0070] At least one of the first electrode sheet and the second electrode sheet includes a plain portion at either side edge in the width direction where no active material layer is applied. When both the first electrode sheet and the second electrode sheet have a plain portion, the plain portion may be provided at each of both side edges in the width direction.

[0071] Accordingly, an uncoated portion may be provided at an axial end of the electrode cell body portion in a protruding form extending in the axial direction.

[0072] The non-coating portion may be removed from a predetermined section adjacent to the core portion in the winding direction.

[0073] The removal of the non-coating portion can be carried out after the electrode laminate is formed and before the winding step, and can be carried out by, for example, laser processing.

[0074] The removal of the uncoated portion may be performed at the stage of providing an electrode sheet before constructing the electrode laminate.

[0075] The removal of the non-coating portion can also be carried out after the electrode laminate is wound up to form the electrode cell body portion, and such processing can be carried out, for example, by using a cutter equipped with an ultrasonically vibrating blade.

[0076] The method for manufacturing the battery cell includes removing a portion of the uncoated portion provided at a lateral end of the electrode cell body portion.

[0077] Specifically, the removing step of the uncoated portion includes a step of cutting the uncoated portion to a predetermined depth in the axial direction while a first cutter unit moves in the axial direction of the battery cell, thereby forming a first cutting line in the uncoated portion in the axial direction.

[0078] A plurality of the first cutting lines may be provided, and the plurality of first cutting lines may be arranged radially.

[0079] In addition, the removing step of the uncoated portion may include forming the first cutting line, and then forming a second cutting line in a circumferential direction in the uncoated portion while a second cutter unit moves radially inward from the outer periphery of the battery cell.

[0080] A plurality of the second cutting lines may be provided, and the second cutting lines may extend in a circumferential direction, and the plurality of second cutting lines may be aligned in a radial direction.

[0081] The circumferential lengths of the second cutting lines may gradually increase from the core side to the outer periphery side in the radial direction.

[0082] The second cutter unit cuts the uncoated portion such that the second cutting line is connected to two circumferentially adjacent first cutting lines, thereby cutting out a portion of the uncoated portion surrounded by the circumferentially formed second cutting line and a pair of first cutting lines respectively connected to both ends of the second cutting line.

[0083] The cut surface portion formed at the cut position of the uncoated portion may be formed in a fan shape along the circumferential direction with the core portion of the electrode cell body portion as the center.

[0084] The cut surface portion may have a central angle of 60° to 120°.

[0085] The method for manufacturing the battery cell may further include forming a forming portion by bending and laying down an uncut portion, which is an uncoated portion remaining after being cut along the cutting line, in a radial direction.

[0086] The bending process can be performed by pressing the non-cut portion in the radial direction with a press portion.

[0087] The forming portion may be formed radially from a core portion of the electrode cell body portion as a center.

[0088] The forming portion may be formed such that an uncut portion of the uncoated portion is laid on a core portion side of the electrode cell body portion.

[0089] The formed portion may be formed along the radial direction of the electrode cell body portion.

[0090] The cut surface portion may be formed by cutting a portion spaced a certain distance outward in the axial direction at a boundary between the non-coating portion and the retaining portion.

[0091] The first cutter may be vibrated by a first vibration generating unit to cut the non-coating portion, and the first cutter may be an ultrasonic cutter.

[0092] The second cutter unit can cut the non-coating portion while being vibrated by the second vibration generating unit.

[0093] The second cutter unit may be an ultrasonic cutter. [Effects of the Invention]

[0094] According to the present invention, since the forming portion is welded to the current collecting plate in a state of surface contact, the larger the area of ​​the forming portion, the larger the current path between the electrode assembly and the current collecting plate can be.

[0095] According to the present invention, since the forming portion increases the current path by an area equal to the spacing between the uncoated portions, even when applied to a large-capacity battery cell, the increase in heat generation of the battery cell can be suppressed, thereby reducing the possibility of fire.

[0096] According to the present invention, after the planned cut portion and the non-cut portion in the uncoated portion are separated from each other, the planned cut portion is cut to form the cut surface portion, and the non-cut portion is pressurized and laid down to form the formed portion. This prevents the boundary portion between the formed portion and the cut surface portion from being torn or irregularly distorted and deformed when the non-cut portion is pressurized to form the formed portion.

[0097] According to the present invention, it is possible to prevent the boundary between the forming portion and the cut surface portion from being torn or deformed, thereby preventing the torn or deformed portion from coming into contact with an electrode sheet of the opposite polarity.

[0098] According to the present invention, the boundary between the non-coating portion and the supporting portion is prevented from being torn or deformed, and therefore, the active material coated on the supporting portion is prevented from being detached from the supporting portion or the bonding strength is prevented from being weakened, thereby suppressing a decrease in the performance and capacity of the battery cell.

[0099] According to the present invention, it is possible to prevent the edge of the separator from being lifted or damaged due to a broken or deformed portion at the boundary, thereby preventing a short circuit between the first electrode sheet and the second electrode sheet, and further reducing the amount of heat generated by the battery cell or the possibility of an explosion.

[0100] According to the present invention, the cut surface portion is formed by cutting the uncoated portion extending in the axial direction in the region that does not constitute the forming portion, thereby reducing the axial length occupied by the uncoated portion at both ends of the electrode cell body portion, thereby further securing the axial volume of the electrode cell body portion accommodated in the battery can, and thus further increasing the electrical capacity relative to the volume of the battery cell.

[0101] The above-mentioned effects and specific effects of the present invention will be described in conjunction with the following description of the preferred embodiment of the invention. [Brief explanation of the drawings]

[0102] [Figure 1] 1 is a plan view schematically illustrating an electrode cell stack according to the present invention. [Figure 2] 2 is a cross-sectional view showing the electrode cell stack of FIG. 1 cut in the AA direction. [Figure 3] 2 is a perspective view showing a state in which the electrode cell stack of FIG. 1 is wound up to produce an electrode cell body portion. FIG. [Figure 4] 10 is a perspective view showing a state in which a first cutter part has cut an electrode cell body part according to the present invention. FIG. [Figure 5] FIG. 2 is a perspective view showing a first cutter unit according to the present invention. [Figure 6]FIG. 3 is a rear view showing the first cutter unit according to the present invention. [Figure 7] 10 is a plan view showing a state in which a second cutter unit according to the present invention has cut an uncoated portion of an electrode cell body unit. FIG. [Figure 8] 10 is a perspective view showing a state before a second cutter unit according to the present invention cuts an uncoated portion of an electrode cell body unit. FIG. [Figure 9] 10 is a side view showing a state in which a second cutter unit according to the present invention cuts an uncoated portion of an electrode cell body unit. FIG. [Figure 10] 10 is a perspective view showing a state in which a press unit presses an uncut portion of an electrode cell body portion after a second cutter unit has cut the uncoated portion of the electrode cell body portion according to the present invention. FIG. [Figure 11] 10 is a perspective view showing a state in which a press unit according to the present invention forms a forming unit that presses an uncut portion. FIG. [Figure 12] 10 is a side view showing a state in which a press unit according to the present invention forms a forming unit that presses an uncut portion. FIG. [Figure 13] 3 is a flowchart illustrating a method for manufacturing a battery cell according to the present invention. [Figure 14] 1 is a cross-sectional view showing an electrode assembly according to the present invention; [Figure 15] 1 is a perspective view showing a state in which an electrode assembly according to the present invention is housed in a pack housing; [Figure 16] 1 is a perspective view showing a state in which a battery pack according to the present invention is mounted on a vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0103] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0104] The present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms and with various modifications. However, the present embodiments are provided to fully disclose the present invention and to fully convey the scope of the invention to those skilled in the art. Therefore, the present invention is not limited to the embodiments disclosed below, and should be understood to include all modifications, equivalents, and alternatives within the technical spirit and scope of the present invention, as well as the substitution or addition of the configuration of any embodiment with the configuration of another embodiment.

[0105] The accompanying drawings are intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to include any modifications, equivalents, or alternatives that fall within the idea and technical scope of the present invention. The components in the drawings may be exaggerated in size or thickness for ease of understanding, but this should not be interpreted as limiting the scope of protection of the present invention.

[0106] The terms used in this specification are merely used to describe particular embodiments and are not intended to limit the present invention. Furthermore, singular terms include plural terms unless the context clearly dictates otherwise. Terms such as "comprises," "consists," and the like in the specification are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. In other words, terms such as "comprises," "consists," and the like in the specification should not be understood to preclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0107] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

[0108] When a component is referred to as being "coupled" or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that there may be other components between them. On the other hand, when a component is referred to as being "directly coupled" or "directly connected" to another component, it should be understood that there are no other components between them.

[0109] When a component is referred to as being "on top of" or "under" another component, it should be understood that it may be located not only directly on top of the other component, but that there may be other components in between.

[0110] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms commonly used and similar to dictionary definitions should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

[0111] Hereinafter, an electrode assembly according to an embodiment of the present invention will be described.

[0112] For ease of explanation, in this specification, the direction along the length of the winding shaft of the electrode assembly 110 wound in a jelly roll shape is referred to as the axial direction (Y). The direction surrounding the winding shaft is referred to as the circumferential direction (X) or peripheral direction. The direction approaching or moving away from the winding shaft is referred to as the radial direction or radial direction (Z). Of these, the direction approaching the winding shaft is particularly referred to as the centripetal direction, and the direction moving away from the winding shaft is particularly referred to as the centrifugal direction.

[0113] FIG. 1 is a plan view schematically showing an electrode cell laminate according to the present invention, FIG. 2 is a cross-sectional view showing the electrode cell laminate of FIG. 1 cut in the AA direction, and FIG. 3 is a perspective view showing the electrode cell laminate of FIG. 1 wound up to produce an electrode cell body portion.

[0114] 1 to 3, an electrode stack 10 according to an embodiment of the present invention includes a first electrode sheet 11, a second electrode sheet 12, and a separator 13. The electrode stack 10 is formed by laminating the separator 13 between sheet-like first and second electrode sheets 11 and 12. For example, the electrode stack 10 may be formed by laminating one first electrode sheet 11, one second electrode sheet 12, and two separators 13. The electrode stack 10 may also be formed by laminating two or more first electrode sheets 11, two or more second electrode sheets 12, and three or more separators 13. As the number of first electrode sheets 11, second electrode sheets 12, and separators 13 stacked in the electrode stack 10 increases, the winding time and manufacturing time for an electrode assembly 110 with a desired diameter can be shortened.

[0115] The first electrode sheet 11 and the second electrode sheet 12 each include a support portion 14 coated with an active material and an uncoated portion 15 not coated with an active material. The uncoated portion 15 may be formed on one widthwise side of the first electrode sheet 11 and the second electrode sheet 12. At least a portion of the uncoated portion 15 may itself be used as an electrode tab. When the electrode assembly 110 is wound into a cylindrical shape, the uncoated portion 15 of the first electrode sheet 11 may be disposed on one axial side (upper or lower side in FIG. 1), and the uncoated portion 15 of the second electrode sheet 12 may be disposed on the other axial side.

[0116] The uncoated portion 15 of the first electrode sheet 11 and the uncoated portion 15 of the second electrode sheet 12 may be formed to have the same width, or the uncoated portion 15 of the first electrode sheet 11 and the uncoated portion 15 of the second electrode sheet 12 may be formed to have different widths.

[0117] 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.

[0118] The first electrode sheet 11 and the second electrode sheet 12 each include a current collector made of a metal foil and an active material layer. The metal foil may be aluminum or copper. The active material layer may be coated on one or both sides of the first electrode sheet 11 and the second electrode sheet 12.

[0119] The width of the non-coating portion 15 is significantly narrower than the width of the maintaining portion 14. The non-coating portion 15 may be formed in a narrow band shape. Alternatively, the non-coating portion 15 may be composed of a plurality of sawtooth-shaped segments spaced apart along the length of the non-coating portion 15. The shapes of the segments may be changed to a rectangle, triangle, semicircle, semi-ellipse, parallelogram, etc.

[0120] The non-coating portion 15 may have a removed section (C) near the core side, which can be removed by laser processing or the like after the electrode stack 10 is formed and before winding.

[0121] Of course, the plain portion of the section (C) may be removed in advance when the electrode sheet is provided, or the removed portion 112a of the core-side plain portion may be formed by post-processing after winding.

[0122] 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 may be any active material known in the art without any limitations.

[0123] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; 1+x Mn 2-x Lithium manganese oxides (LiMnO2), such as LiMnO4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides, such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x M x O2 (where M=Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x=0.01 to 0.3); 2-x M x The main component may be a lithium intercalation material, such as a lithium manganese composite oxide represented by LiMnO2 (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 substituted with an alkaline earth metal ion; a disulfide compound; Fe2(MoO4)3, or a composite oxide formed by a combination of these. Positive electrode active materials include, but are not limited to, the types described above.

[0124] The positive electrode current collector has a thickness of, for example, 3 to 500 μm. There are no particular limitations on the positive electrode current collector, as long as it does not induce chemical changes in the battery and is conductive. For example, the positive electrode current collector can be made of stainless steel, aluminum, nickel, titanium, baked carbon, or aluminum or stainless steel whose surface has been treated with carbon, nickel, titanium, silver, or the like. The electrode current collector can also have fine irregularities formed on its surface to increase the adhesive strength of the positive electrode active material. These electrode current collectors can be in various forms, such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.

[0125] The positive electrode active material particles may further contain a conductive material. The conductive material may be added in an amount of, for example, 1 to 50 wt % based on the total weight of the mixture containing the positive electrode active material. There are no particular limitations on the conductive material, as long as it does not induce chemical changes in the battery and has high conductivity. Examples of conductive materials that can be used include graphites such as natural graphite and artificial graphite; carbon blacks such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0126] The negative electrode sheet is prepared by coating and drying negative electrode active material particles on a negative electrode current collector, and may further contain components such as the aforementioned conductive material, binder, and solvent, as needed.

[0127] 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 induce chemical changes in the battery and have conductivity. For example, the negative electrode current collector can be made of copper, stainless steel, aluminum, nickel, titanium, fired carbon, or a material obtained by surface treatment 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.

[0128] 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.

[0129] The binder polymer usable in the electrode sheet is a component that helps bind the electrode active material particles with the conductive material and the like and also aids in binding to the electrode current collector, and is added in an amount of, for example, 1 to 50 wt % based on the total weight of the mixture including the electrode active material. Examples of these binder polymers include polyvinylidene fluoride-co-hexafluoropropylene (PVdF), polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, ethylene-vinyl acetate copolymer (polyethylene-co-vinyl acetate), polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. The binder polymer may be any one selected from the group consisting of cellulose acetate, cellulose acetate ester ...

[0130] Non-limiting examples of solvents that can be used in the manufacture of the electrode include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water, or mixtures thereof. These solvents provide an appropriate level of viscosity so that a slurry coating layer can be formed at a desired level on the surface of the electrode current collector.

[0131] The separator 13 includes a porous polymer substrate and porous coating layers disposed on both sides of the porous polymer substrate, the coating layers including inorganic particles and a binder polymer.

[0132] The porous polymer substrate may be a polyolefin-based porous substrate.

[0133] The polyolefin porous substrate may be in the form of a film or a non-woven web. The porous structure facilitates smooth electrolyte transfer between the positive and negative electrodes. The porous structure also increases the electrolyte impregnation of the substrate itself, ensuring excellent ionic conductivity and preventing an increase in the internal resistance of the electrochemical device, thereby preventing performance degradation of the electrochemical device.

[0134] The polyolefin porous substrate used in the present invention can be any planar porous substrate typically used in electrochemical elements, and its material and shape can be selected in a variety of ways depending on the intended purpose.

[0135] The polyolefin porous substrate may be, but is not limited to, a film or nonwoven 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.

[0136] The polyolefin porous substrate may have a thickness of 8 to 30 μm, but this is merely an example, and thicknesses outside the above range may be adopted in consideration of mechanical properties and efficient charge / discharge characteristics of the battery.

[0137] The separator 13 according to the present invention may have a thickness of 1 to 100 μm or 5 to 50 μm. If the thickness of the separator 13 is less than 1 μm, the separator 13 may not function sufficiently and mechanical properties may deteriorate. If the thickness of the separator 13 is more than 100 μm, battery properties may deteriorate during high-rate charge / discharge. In addition, the separator 13 may have a porosity of 40 to 60% and an air permeability of 150 to 300 seconds / 100 mL.

[0138] When using a separator 13 according to an embodiment of the present invention, porous coating layers are provided on both sides of a porous polymer substrate, which improves the electrolyte impregnation performance and allows the formation of a uniform solid electrolyte interfacial layer, thereby ensuring superior air permeability compared to conventional cross-section inorganic-coated separators 13. For example, the air permeability may be within 120 s / 100 cc. Furthermore, even when inorganic porous coating layers are provided on both sides, the thickness can be the same as that of conventional cross-section inorganic-coated separators 13. For example, the thickness may be within 15.0 μm.

[0139] Furthermore, when the separator 13 according to an embodiment of the present invention is used, the stability of the separator 13 is improved, and heat resistance and pressure resistance properties can be ensured. Specifically, heat resistance properties such as thermal shrinkage of 5% or less at 180°C can be ensured, and a puncture strength of 550 gf or more can be ensured. When core deformation occurs during the cycle of a battery using such a separator 13, damage or puncture of the separator 13 at the step portion can be prevented.

[0140] An electrode assembly manufactured using the above-described electrode laminate will now be described.

[0141] FIG. 4 is a perspective view showing a state in which a first cutter unit according to the present invention has cut an electrode cell body portion, FIG. 5 is a perspective view showing a first cutter unit according to the present invention, FIG. 6 is a rear view showing a first cutter unit according to the present invention, FIG. 7 is a plan view showing a state in which a second cutter unit according to the present invention has cut an uncoated portion of an electrode cell body portion, FIG. 8 is a perspective view showing a state before the second cutter unit according to the present invention has cut the uncoated portion of an electrode cell body portion, FIG. 9 is a side view showing a state in which the second cutter unit according to the present invention is cutting the uncoated portion of an electrode cell body portion, FIG. 10 is a perspective view showing a state in which the press unit presses the uncut portion after the second cutter unit according to the present invention has cut the uncoated portion of an electrode cell body portion, FIG. 11 is a perspective view showing a state in which the press unit according to the present invention has formed a forming portion that presses the uncut portion, and FIG. 12 is a side view showing a state in which the press unit according to the present invention has formed a forming portion that presses the uncut portion.

[0142] 4 to 12, the electrode assembly 110 includes an electrode cell body portion 111, a plurality of cutting surface portions 115, and a plurality of forming portions 117.

[0143] The electrode cell body 111 is a cylindrical portion wound up in a jelly roll shape with the separator 13 laminated between the sheet-like first electrode sheet 11 and second electrode sheet 12. As described above, the uncoated portions 15, which are not coated with an active material layer, are formed at the widthwise ends of the first electrode sheet 11 and the second electrode sheet 12, and these are disposed on one and the other axial sides of the electrode cell body 111, respectively, and extend in the axial direction.

[0144] The electrode cell body 111 can be formed by winding the laminate extending in the longitudinal direction around a winding rod (not shown) and removing the winding rod from the electrode cell body 111. In this case, the more first electrode sheets 11, second electrode sheets 12, and separators 13 are stacked on the electrode laminate 10, the shorter the winding time and manufacturing time for the electrode assembly 110 can be. The area where the winding rod is removed from the electrode cell body 111 forms a hollow core 112.

[0145] On one axial side of the electrode cell body portion 111, the uncoated portion 15 of the first electrode sheet 11 is exposed to a certain height, and on the other axial side of the electrode cell body portion 111, the uncoated portion 15 of the second electrode sheet 12 is exposed to a certain height.

[0146] Furthermore, due to the removal portion (C) of the non-coating portion, a recessed portion 112a is provided in the non-coating portion section adjacent to the core portion 112.

[0147] The first cutter unit 210 cuts the uncoated portion 15 of the electrode cell body unit 111 in the axial direction to separate the portion to be cut 115a and the non-cut portion 117a in the circumferential direction. A first cutting line 113 is formed between the portion to be cut 115a and the non-cut portion 117a. The first cutting line 113 is formed to extend in the axial direction from the axial end of the uncoated portion 15 toward the electrode cell body unit 111. At this time, the portion to be cut 115a and the non-cut portion 117a maintain a standing state along the axial direction of the electrode cell body unit 111.

[0148] The second cutter unit 220 radially cuts the axially lower portion of the portion to be cut 115a of the non-coating portion 15 to remove the portion to be cut 115a from the electrode cell body portion 111. The second cutter unit 220 forms second cutting lines 16a extending in the circumferential direction on the lower portion of the non-coating portion 15 in the area corresponding to the portion to be cut 115a. The second cutting lines 16a are formed along the circumferential direction of the non-coating portion 15 and are provided below adjacent non-coating portions arranged radially. When both circumferential ends of the second cutting line are connected to the first cutting lines 13 on both circumferential sides of the portion to be cut 115a, the portion to be cut 115a surrounded by the pair of first and second cutting lines 13 is cut from the electrode cell body portion 111. The short portion of the non-coating portion remaining after the portion to be cut 115a is cut forms the cut surface portion 115.

[0149] As a result, the uncoated portion 15 of the electrode cell body portion 111 is provided with a cut surface portion 115 and a non-cut portion 117a.

[0150] The first cutter unit 210 for cutting the first cutting line 113 may use an ultrasonic cutter to prevent buckling that may occur when cutting a thin plain portion in the axial direction.

[0151] The first cutter unit 210 includes a plurality of first blades 211 arranged in a direction corresponding to the radial direction of the electrode cell body unit 111, and a first vibration generating unit 213 to which the first blades 211 are fixed.

[0152] The first vibration generating unit 213 includes a circular plate and a vibration source for vibrating the circular plate.

[0153] The plurality of first blades 211 may have their base ends fixed to the surface of the circular plate of the first vibration generating part 213, extend in a direction corresponding to the axial direction of the electrode cell body part 111, and have sharp blades at their tips.

[0154] The plurality of first blades 211 are arranged radially with respect to the center of the first vibration generating unit 213. For example, a pair of first blades 211 defining the non-cut portion 117a may be formed in four locations in a cross shape with respect to the center of the first vibration generating unit 213. Alternatively, the pair of first blades 211 may be arranged radially at six locations at 60° intervals. Alternatively, the pair of second blades 221 may be arranged radially at three locations at 120° intervals. The angle between the pair of first blades 211 can be appropriately selected depending on the diameter of the electrode cell body 111, the capacity of the battery pack, and the shape of the current collecting plate to be welded thereto.

[0155] In the embodiment, a preferred structure is illustrated in which the pair of first blades 211 defining the non-cut portion 117a are arranged parallel to each other. However, the pair of first blades 211 do not necessarily need to be arranged parallel to each other. For example, the pair of first blades 211 may be configured so that the distance between them gradually increases toward the centrifugal direction, or the distance between them gradually increases toward the centripetal direction. Furthermore, although the first blades 211 are illustrated as being linear, the first blades 211 do not necessarily need to be linear. For example, the first blades 211 may be gently curved.

[0156] The circumferential distance between one pair of first blades 211 and another adjacent pair of first blades 211 becomes closer in the centripetal direction and becomes farther away in the centrifugal direction. In other words, this can define the fan shape of the cutting surface portion 115.

[0157] In order to process the second cutting line by the second cutter unit 220 described later, it is preferable that the circumferential distance between the pair of first blades 211 and another pair of first blades 211 adjacent to it is closer to each other in the centripetal direction, or closer to each other in the centrifugal direction.

[0158] The first vibration generating unit 213 may include an ultrasonic vibrator. A first communication hole 215 is formed in the center of the first vibration generating unit 213 to communicate with the core unit. The first vibration generating unit 213 generates ultrasonic vibrations when the first blade 211 moves in the axial direction of the electrode cell body unit 111 and cuts the uncoated portion 15.

[0159] If the force with which the first blade 211 presses the plain portion 15 in the axial direction is not used to process the cutting line 113, and the force pressing the plain portion 15 down may cause deformation such as buckling of the plain portion 15 or warping or bending of the portion of the plain portion 15 near the first cutting line 113.

[0160] When the first blade 211 is ultrasonically vibrated, the above-mentioned phenomenon is prevented when the first blade 211 cuts the non-coating portion 15, and the cutting process is performed very smoothly. This improves the cutting speed of the non-coating portion 15 and makes it possible to smoothly form the first cutting line 113 in the non-coating portion 15. Various vibration methods can be applied to the first vibration generating unit 213 as long as it vibrates the first blade 211.

[0161] The second cutter unit 220 includes a second blade 221 that cuts the uncoated portion 15 in the radial direction, and a second vibration generating unit 223 to which the second blade 221 is fixed.

[0162] The second blade 221 may have a shape in which its width becomes thinner toward the tip. Specifically, the second blade 221 may have a triangular plate or a wedge-shaped plate. For example, the apex of the second blade 221 may be formed at an angle (θ2) of 60 to 120 degrees. The angle (θ2) of the apex of the second blade 221 is formed to correspond to the central angle of the cutting surface portion 115 described below. In the embodiment, the twelfth blade 221 has an apex angle of approximately 90 degrees, for example. The second blade 221 may be double-edged. That is, cutting edges may be provided at positions corresponding to two oblique sides extending to the tip.

[0163] As the second blade advances radially to form the second cutting line, the sharp tip of the second blade first cuts the circumferential center of the section to be cut 115a of the non-coated area. As the second blade advances centripetally, the two blades expand the second cutting line to both sides in the circumferential direction. When the second blade applies force to the side of the non-coated area in the radial direction, the force is concentrated at the sharp tip, rather than contacting the side of the non-coated area all at once. Therefore, when forming the second cutting line on the side of the non-coated area, the non-coated area is pressed to the side and does not deform. After the tip cuts the non-coated area, the second cutter moves centripetally, and the two blades of the second cutter apply pressure to the second cutting line in the circumferential direction to cut it. The cutting method and direction of the second cutter minimize deformation of the non-coated area.

[0164] The second vibration generating unit 223 may include an ultrasonic vibrator. The second vibration generating unit 223 generates ultrasonic vibrations when the second blade 221 moves in the radial direction of the electrode cell body 111 and cuts the uncoated portion 15. This may improve the cutting speed of the uncoated portion 15 and allow the cut surface 115 to be formed smoothly. The second vibration generating unit 223 may use various vibration methods as long as it vibrates the second blade 221.

[0165] A recess 112a is formed between the uncoated portion 15 and the core portion 112 on one or both axial sides of the electrode cell body portion 111. The recess 112a is formed in an annular shape so as to surround the core portion 112.

[0166] The radial width (W2) of the recessed portion 112a may be the same as, slightly wider than, or narrower than the height (W1) of the uncoated portion 15. The recessed portion 112a is formed concentrically with the core portion 112. The recessed portion 112a may be flush with the cut surface portion 115 or slightly lower than the cut surface portion 115.

[0167] The plurality of cut surface portions 115 are formed by cutting out portions to be cut 115a, which are parts of the uncoated portion 15, along the circumferential direction around the core portion 112 of the electrode cell body portion 111. In this case, the plurality of cut surface portions 115 may be arranged at equal intervals along the circumferential direction around the core portion 112. Furthermore, the plurality of cut surface portions 115 may be formed to have the same size and the same shape.

[0168] The multiple formed portions 117 are formed by pressing and laying down the uncut portions 117a of the uncoated portion 15 arranged between the cut surface portions 115 in a direction intersecting the axial direction, for example, in the radial direction. The multiple formed portions 117 may be formed by pressing and laying down the uncut portions 117a of the uncoated portion 15 using a press unit 230 described below. In this case, the multiple formed portions 117 may be formed by laying down multiple uncut pieces that make up the uncut portions 117a in a continuous overlapping manner. As a result, the formed portion 117 may be formed at an angle with respect to the axial direction of the electrode cell body portion 111, or may be formed completely flat by being laid down.

[0169] The plurality of formed portions 117 are welded to the current collecting plates 130 and 140 to form current paths. Furthermore, the plurality of cut surface portions 115 may also be welded to the current collecting plates 130 and 140. However, since the cut surface portions 115 are welded (e.g., laser welded) to the current collecting plates 130 and 140 while in line contact with the current collecting plates 130 and 140, the cut surface portions 115 do not have as great an effect of increasing the current paths as compared with the formed portions 117. On the other hand, since the formed portions 117 are formed by laying the non-cut portions 117a in the radial direction, the formed portions 117 cover the gaps between the uncoated portions 15 spaced apart by the thickness of the separator 13. These forming portions 117 are welded to the current collecting plates 130 and 140 in surface contact, and therefore the larger the area of ​​the forming portions 117, the greater the relative increase in the current path between the electrode assembly 110 and the current collecting plates 130 and 140. These forming portions 117 increase the current path by the combined area of ​​the gaps between the uncoated portions 15, and therefore, even when applied to a large-capacity battery cell 100, an increase in the amount of heat generated by the battery cell 100 can be suppressed, thereby reducing the possibility of fire.

[0170] If the cut surface portion 115 is exposed without being welded to the current collecting plates 130 and 140, the impregnation of the electrolyte may be improved when the electrolyte is injected into the electrode assembly. Although the impregnation of the electrolyte may be weakened in the area of ​​the forming portion 117 due to the bending of the uncut piece, the cut surface portion 115, which is adjacent to the forming portion 117, compensates for this, so there is no particular problem with the impregnation of the electrolyte.

[0171] According to the present invention, the portions to be cut 115a and the non-cut portions 117a in the uncoated portion 15 are separated from each other in the circumferential direction by a first cutter unit that forms a first cutting line in the axial direction, and then the lower end of the portions to be cut 115a is cut by a second cutter unit to form the cut surface portions 115, and the non-cut portions 117a are pressurized and laid down to form the formed portions 117. This makes it possible to prevent the boundary portions 16 between the formed portions 117 and the cut surface portions 115a from being torn or deformed irregularly when pressurizing the non-cut portions 117a to form the formed portions 117.

[0172] Furthermore, since the boundary 16 between the forming portion 117 and the cut surface portion 115a can be prevented from being torn or deformed, contact with the electrode sheets 11 and 12 of opposite polarity at the torn or deformed portion can be prevented. Furthermore, since the boundary 16 between the non-coating portion 15 and the maintaining portion 14 can be prevented from being torn or deformed, the active material coated on the maintaining portion 14 can be prevented from being detached from the maintaining portion 14 or the bonding strength can be prevented from being weakened. As a result, a decrease in the performance and capacity of the battery cell 100 can be suppressed.

[0173] In addition, the edge of the separator 13 can be prevented from being lifted or damaged due to a torn or deformed portion of the boundary portion 16. This can prevent a short circuit between the first electrode sheet 11 and the second electrode sheet 12. Furthermore, the amount of heat generated by the battery cell 100 can be reduced, and the possibility of an explosion can be significantly reduced.

[0174] Furthermore, since the forming portion 117 is formed by compressing the non-cut portion 117a with the cut surface portions 115 removed from both sides of the non-cut portion 117a, it is possible to prevent the uncut pieces of the non-cut portion 117a from tilting and opening due to a spring back phenomenon. Furthermore, when the press unit 230 is used to apply strong pressure to the non-cut portion 117a, the forming portion 117 (the uncut pieces of the non-cut portion 117a) can be superimposed on the cut surface portion 115 in a state of being as flat and tightly attached as possible. As a result, the forming portion 117 and the cut portion are welded to the current collecting plates 130 and 140 in surface contact, thereby significantly increasing the weld cross-sectional area. Furthermore, an increase in the weld cross-sectional area increases the cross-sectional area of ​​the current path, which advantageously significantly reduces the resistance of the battery cell 100. This is because resistance is inversely proportional to the cross-sectional area of ​​the path through which current flows.

[0175] The cut surface portion 115 is formed in a fan shape along the circumferential direction, with the core portion 112 of the electrode cell body portion 111 as the center. The apex of the cut surface portion 115 faces 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, with the core portion 112 as the center. Furthermore, the outer width of the forming portion 117 may be the same as or wider than the width of the core portion 112 along the central angle of the fan-shaped cut surface portion 115.

[0176] The cut surface portion 115 may have a central angle (θ1: see FIG. 7) of 60° to 120°. The central angle (θ1) is the angle between the vertex of the sector and both sides. When the central angle (θ1) of the cut surface portion 115 is 90°, four cut surface portions 115 may be formed in a cross shape in the circumferential direction of the non-coated portion 15. When the central angle (θ1) of the cut surface portion 115a is 60°, six cut surfaces may be formed in the circumferential direction of the non-coated portion 15. When the central angle (θ1) of the cut surface portion 115a is 120°, three cut surfaces may be formed in the circumferential direction of the non-coated portion 15. In the present invention, the central angle of the cut surface portion is not limited to the above range. For example, the central angle may be 45 degrees, 30 degrees, or 180 degrees.

[0177] The cut surface portion 115 may be formed by cutting a portion 16a that is spaced a certain distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the supporting portion 14. In this way, the second cutter unit 220 cuts the uncoated portion 15 at a position spaced apart from the supporting portion 14, thereby preventing the active material coated on the supporting portion 14 from being detached. Furthermore, even if the uncoated portion 15 is slightly deformed when cut, the supporting portion 14 can be prevented from being damaged or deformed.

[0178] The central angle of the cut surface portion 115 can be appropriately selected taking into consideration the diameter of the electrode cell body portion 111, the capacity of the battery cell 100, and the like. 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 formed to 60°. This is because, as the diameter of the electrode cell body portion 111 increases, the enlargement of the cross-sectional area of ​​the current path is advantageous for preventing heat generation and fire, and the central angle of the cut surface portion 115 is reduced to increase the area of ​​the forming portion 117. Furthermore, the larger the capacity of the electrode cell body portion 111, the closer the central angle of the cut surface portion 115 can be formed to 60°.

[0179] The forming portions 117 may 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 of the cut surface portion 115 is 90°. When six forming portions 117 are formed radially around the core portion 112, the central angle of the cut surface portion 115 is 60°. When three forming portions 117 are formed radially around the core portion 112, the central angle of the cut surface portion 115 is 120°. Because the forming portions 117 are formed radially around the core portion 112, the current paths are uniformly dispersed in the circumferential direction of the electrode cell body portion 111.

[0180] The forming portion 117 may be formed in a shape in which the uncut portion 117a of the plain portion 15 is laid on the core portion 112 side of the electrode cell body portion 111. This prevents the forming portion 117 from protruding outward from the outer circumferential surface of the electrode cell body portion 111, so that the electrode assembly 110 can be smoothly inserted into the battery can 120 when manufacturing the battery cell 100. In addition, the forming portion 117 can be prevented from hanging over the battery can 120.

[0181] When the uncut portion 117a is laid on the core portion 112 side of the electrode cell body portion 111, the uncut portion 117a adjacent to the core portion 112 may block the core portion 112. That is, as shown in FIG. 1(a), an electrode cell body portion 111 manufactured without removing a section of the uncoated portion located on the core side does not have a recess portion 112a. If the uncut portion 117a is also present in the uncoated portion adjacent to the core portion 112, the uncoated portion 15 adjacent to the core portion 112 may be laid, causing the forming portion 117 to block the core portion 112.

[0182] The core portion 112 can serve as a passage for introducing an electrolyte or, in some cases, a passage for inserting a welding rod. In this regard, it is preferable that the core portion 112 be open in the axial direction. Therefore, as shown in FIG. 1(b), if a section of the uncoated portion located on the core side is pre-cut and the electrode assembly is fabricated as described above, a recess portion 112a is formed in which the uncoated portion adjacent to the core portion 112 is removed. If the forming portion 117 is formed in this state, the core portion 112 will not be blocked.

[0183] The radial width (W2) of the recessed portion 112a may be formed to be the same as the height (W1) of the uncoated portion (see FIG. 9). Of course, the radial width (W2) of the recessed portion 112a may be formed to be slightly wider or narrower than the height (W1) of the uncoated portion.

[0184] The forming portions 117 may be formed uniformly in the radial direction of the electrode cell body portion 111. The forming portions 117 may be formed symmetrically with respect to the core portion 112 of the electrode cell body portion 111. This allows the forming portions 117 to form current paths of almost the same area in the radial direction of the electrode cell body portion 111.

[0185] A core portion 112 may be formed at the center of the electrode cell body portion 111. The core portion 112 is formed to have 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 to have a hollow shape, an electrolyte injector (not shown) can inject electrolyte through the core portion 112 after the electrode assembly 110 is placed in the battery can 120. This reduces the time required to inject the electrolyte, thereby reducing the time required to manufacture the battery cell 100. In addition, when the electrolyte injector is inserted into the core portion 112, the electrode sheets 11 and 12 and the separator 13 near the core portion 112 can be prevented from being caught and torn or damaged.

[0186] The electrode cell body portion 111 may be formed in a cylindrical shape, which allows the electrode cell body portion 111 to be inserted into the cylindrical battery can 120 so that the outer surface of the electrode cell body portion 111 is in close contact with the inner surface of the cylindrical battery can 120.

[0187] Next, a method for manufacturing a battery cell according to the present invention will be described.

[0188] A separator 13 is laminated between sheet-like first and second electrode sheets 11 and 12 (S11). At this time, the structure in which the first electrode sheet 11, the second electrode sheet 12, and the separator 13 are laminated is called an electrode stack 10. In the electrode stack 10, the uncoated portion 15 of the first electrode sheet 11 protrudes to one widthwise side of the electrode stack 10, and the uncoated portion 15 of the second electrode sheet 12 protrudes to the other widthwise side of the electrode stack 10.

[0189] The first electrode sheet 11, the second electrode sheet 12, and the separator 13 are wound into a jelly roll shape (S12). At this time, the electrode stack 10 is wound around 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 has been removed. 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 separators 13 are stacked on the electrode stack 10, the shorter the winding time and manufacturing time for the electrode assembly 110 can be.

[0190] The first cutter unit 210 moves in the axial direction of the battery cell 100 and radially cuts the uncoated portions 15 of the first electrode sheet 11 and the second electrode sheet 12 (S13). At this time, the first cutter unit 210 cuts the uncoated portion 15 of the electrode cell body portion 111 in the axial direction to separate the portion to be cut 115a and the portion not to be cut 117a. At this time, the portion to be cut 115a and the portion not to be cut 117a maintain a standing state along the axial direction of the electrode cell body portion 111.

[0191] The second cutter unit 220 cuts a part of the uncoated portion 15 to form a cut surface portion 115 while moving in the radial direction of the battery cell 100 (S14). The second cutter unit 220 cuts the portion to be cut 115a of the uncoated portion 15 in the radial direction to remove the portion to be cut 115a from the electrode cell body portion 111. This separates the cut surface portion 115 and the non-cut portion in the uncoated portion 15 of the electrode cell body portion 111 from each other.

[0192] The press unit 230 applies pressure to the uncut portions 117a of the uncoated portion 15 and lays them down, thereby forming the formed portion 117 (S15). The multiple formed portions 117 are arranged between the cut surface portions 115 and are formed by applying pressure to the uncut portions 117a of the uncoated portion 15 and laying them down. The multiple formed portions 117 may be formed by applying pressure to the uncut portions 117a of the uncoated portion 15 and laying them down using the press unit 230 described below. In this case, the multiple formed portions 117 may be formed by laying down the multiple uncut pieces that make up the uncut portions 117a in a continuous overlapping manner. As a result, the formed portion 117 may be formed at a slight incline in the axial direction of the electrode cell body portion 111.

[0193] Because the cut surface portions 115 are laser-welded to the current collecting plates 130, 140 in line contact with the current collecting plates 130, 140, the cut surface portions 115 do not substantially increase the current path. Meanwhile, the forming portions 117 are formed by radially extending the uncut portions 117a, so that the forming portions 117 cover the gaps between the uncoated portions 15 spaced apart by the thickness of the separator 13. Because the forming portions 117 are welded to the current collecting plates 130, 140 in surface contact with the current collecting plates 130, 140, the larger the area of ​​the forming portions 117, the greater the relative increase in the current path between the electrode assembly 110 and the current collecting plates 130, 140. Because the forming portions 117 increase the current path by the area including the gaps between the uncoated portions 15, even when applied to a large-capacity battery cell 100, the increase in heat generation from the battery cell 100 can be suppressed, reducing the risk of fire.

[0194] After the portions to be cut 115a and the non-cut portions 117a in the plain portion 15 are separated from each other, the portions to be cut 115a are cut to form the cut surface portions 115, and the non-cut portions 117a are pressed and laid down to form the formed portions 117. This prevents the boundary portions 16 between the formed portions 117 and the cut surface portions 115 from being torn or deformed irregularly when the non-cut portions 117a are pressed to form the formed portions 117.

[0195] In addition, the edge of the separator 13 can be prevented from being lifted or damaged due to a torn or deformed portion of the boundary portion 16. This can prevent a short circuit between the first electrode sheet 11 and the second electrode sheet 12. Furthermore, the amount of heat generated by the battery cell 100 can be reduced, and the possibility of an explosion can be significantly reduced.

[0196] The cut surface portions 115 may be formed in a fan shape along the circumferential direction with the core portion 112 of the electrode cell body portion 111 as the center. The apex of the cut surface portions 115 faces the core portion 112. Because the cut surface portions 115 are formed in a fan shape, each forming portion 117 may be arranged radially between the multiple cut surface portions 115 with the core portion 112 as the center.

[0197] The cut surface portions 115 may have a central angle (θ1) of 60° to 120°. For example, if the central angle (θ1) of the cut surface portions 115 is 90°, four cut surface portions 115 may be formed in a cross shape in the circumferential direction of the uncoated portion 15. If the central angle (θ1) of the cut surface portions 115 is 60°, six cut surfaces may be formed in the circumferential direction of the uncoated portion 15. If the central angle (θ1) of the cut surface portions 115 is 120°, three cut surfaces may be formed in the circumferential direction of the uncoated portion 15.

[0198] The cut surface portion 115 may be formed by cutting a portion spaced a certain distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the supporting portion 14. As a result, the second cutter unit 220 cuts the uncoated portion 15 at a position spaced apart from the supporting portion 14, thereby preventing the active material coated on the supporting portion 14 from being detached. Furthermore, even if the uncoated portion 15 is slightly deformed when cut, the supporting portion 14 can be prevented from being damaged or deformed.

[0199] The forming portions 117 may 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 paths can be uniformly dispersed in the circumferential direction of the electrode cell body portion 111.

[0200] The forming portion 117 may be formed in a shape in which the uncut portion 117a of the uncoated portion 15 lies on the core portion 112 side of the electrode cell body portion 111. This prevents the forming portion 117 from protruding outward from the outer circumferential surface of the electrode cell body portion 111, so that the electrode assembly 110 can be smoothly inserted into the battery can 120 when manufacturing the battery cell 100. In addition, the forming portion 117 can be prevented from hanging over the battery can 120.

[0201] The formed portion 117 may be formed along the radial direction of the electrode cell body portion 111. The formed portion 117 may be formed symmetrically with the core portion 112 of the electrode cell body portion 111 as the center.

[0202] The first cutter unit 210 cuts the uncoated portion 15 while vibrating due to the first vibration generating unit 213. The first vibration generating unit 213 may include an ultrasonic vibrator. Since the cutter unit 210 cuts the uncoated portion 15 while vibrating, the cutting performance and cutting speed of the uncoated portion 15 can be improved.

[0203] The second cutter unit 220 cuts the uncoated portion 15 while vibrating due to the second vibration generating unit 223. The second vibration generating unit 223 may include an ultrasonic vibrator. Since the second cutter unit 220 cuts the uncoated portion 15 while vibrating, the cutting performance and cutting speed of the uncoated portion 15 may be improved.

[0204] It is preferable that the above-mentioned cutting surface portion is processed by the first cutter section first, and then by the second cutter section.

[0205] A battery cell manufactured using the above electrode assembly will now be described.

[0206] Referring to FIG. 13, a 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 collecting plate .

[0207] The electrode assembly 110 is substantially the same as that described above, and therefore, a description thereof will be omitted.

[0208] The electrode assembly 110 is accommodated inside the battery can 120. The battery can 120 is electrically connected to either the first electrode sheet 11 or the second electrode sheet 12 and has a first polarity. The battery can 120 may be made of a conductive material to allow current to flow. For example, the battery can 120 may be made of a material including stainless steel, aluminum, etc. The battery can 120 may be formed in a cylindrical shape with an open end on one side.

[0209] The sealing cap 150 seals the open end of the battery can 120. The sealing cap 150 is installed to be insulated from the battery can 120. The sealing cap 150 prevents external foreign matter and moisture from penetrating into the battery can 120.

[0210] The first current collecting plate 130 has a second polarity and is electrically connected to the other of the first electrode sheet 11 and the second electrode sheet 12. The first current collecting plate 130 may be disposed between the electrode assembly 110 and the sealing cap portion 150. The first current collecting plate 130 is electrically connected to the sealing cap portion 150. The first current collecting plate 130 may be welded to the uncoated portion 15 of the other of the first electrode sheet 11 and the second electrode sheet 12. In this case, the formed portion 117 of the uncoated portion 15 may be welded to the first current collecting plate 130 in line contact, and the cut surface portion 115 of the uncoated portion 15 may be welded to the first current collecting plate 130 in line contact. This increases the weld cross-sectional area between the uncoated portion 15 and the first current collecting plate 130, thereby increasing the cross-sectional area of ​​the current path and significantly reducing the electrical resistance of the battery cell 100. Furthermore, the amount of heat generated by the battery cell 100 can be reduced, making it possible to lower the possibility of the battery cell 100 catching fire.

[0211] 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.

[0212] An electrolyte solution is poured into the battery can 120 through the core portion 112 of the electrode assembly 110 .

[0213] The electrolyte is A + B - The salt may have the following structure: + Li + , Na + , K. + These include alkali metal cations such as B 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 - The anion comprises at least one anion selected from the group consisting of:

[0214] The electrolyte may also be dissolved in an organic solvent, such as 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 a mixture thereof.

[0215] The sealing cap part 150 may further include an insulator 157 that covers the first current collecting plate 130 and has an edge interposed between the inner circumferential surface of the support part 122 and the first current collecting plate 130. The insulator 157 electrically insulates the sealing cap part 150 from the battery can 120.

[0216] The insulator 157 may be made of an insulating polymer resin, such as polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0217] The sealing cap portion 150 includes a cap plate 151 attached to close the open end of the battery can 120. The cap plate 151 may be formed in a disk shape as a whole. An external terminal 152 is formed at the center of the cap plate 151 so as to protrude outward (toward the upper side in FIG. 13).

[0218] The sealing cap part 150 includes a vent plate 153 disposed under the cap plate 151. The vent plate 153 breaks when the internal pressure of the battery can 120 exceeds a predetermined pressure. The vent plate 153 prevents the battery cell 100 from exploding.

[0219] The bent plate 153 and the first current collecting plate 130 are electrically connected by a lead portion 155. The bent plate 153 also contacts the cap plate 151 to form a part of a current path.

[0220] A supporter part 122 is formed below the open end of the battery can 120, and is recessed into the inside of the battery can 120. A vent plate 153 and a cap plate 151 are stacked above the supporter part 122.

[0221] Insulators 157 are interposed between the inner surface of the supporter portion 122, the vent plate 153, and the periphery of the cap plate 151. The insulators 157 cover the first current collecting plate 130, and their edges are interposed between the inner circumferential surface of the supporter portion 122 and the first current collecting plate 130. These insulators 157 form part of the sealing cap portion 150.

[0222] 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 to seal the gap between the periphery of the cap plate 151 and the open end of the battery can 120. The supporter portion 122 and the clamping portion 123 press and fix the peripheries of the first current collecting plate 130 and the vent plate 153, thereby restricting movement of the first current collecting plate 130 and the vent plate 153, thereby improving the assembly stability of the battery cell 100. In addition, leakage of the sealed contents of the battery can 120 due to external impact can be prevented.

[0223] The battery can 120 of either the first electrode sheet 11 or the second electrode sheet 12 may be electrically connected via the second current collecting plate 140. In this case, the second current collecting plate 140 may be welded to a non-coating 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 non-coating portion 15 may be welded to the second current collecting plate 140 using a laser. This increases the weld cross-sectional area between the non-coating portion 15 and the second current collecting plate 140, thereby increasing the cross-sectional area of ​​the current path and significantly reducing the electrical resistance of the battery cell 100. In addition, the amount of heat generated by the battery cell 100 may be reduced, thereby reducing the possibility of the battery cell 100 catching fire.

[0224] Furthermore, it goes without saying that the uncoated portion 15 formed on either the first electrode sheet 11 or the second electrode sheet 12 may be directly welded to the inner surface of the battery can 120 .

[0225] FIG. 15 is a perspective view showing the electrode assembly according to the present invention housed in a pack housing.

[0226] 15, a 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 accommodates the assembly. The cylindrical battery cells 100 may be any of the battery cells 100 according to the above-described embodiments. For convenience of illustration, components such as a bus bar (not shown), a cooling unit (not shown), and external terminals (not shown) for electrically connecting the cylindrical battery cells 100 are omitted in the drawings.

[0227] The battery pack may be mounted on a vehicle 300. The vehicle 300 may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may be a four-wheeled vehicle or a two-wheeled vehicle.

[0228] FIG. 16 is a diagram illustrating a vehicle including a battery pack according to the present invention.

[0229] 16, a vehicle 300 according to an embodiment of the present invention includes a battery cell 100 according to an embodiment of the present invention. The vehicle is operated by receiving power from the battery cell 100 according to an embodiment of the present invention.

[0230] Although the present invention has been described above with reference to exemplary drawings, the present invention is not limited to the embodiments and drawings disclosed in this specification, and various modifications may be made by those skilled in the art 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 while describing the embodiments of the present invention, it is natural that the effects that can be predicted by the configuration should also be recognized. [Explanation of symbols]

[0231] 10 Electrode laminate 11 First electrode sheet 12 Second electrode sheet 13 Separation membrane 14 Maintenance Department 15 Plain area 16 Boundary 16a Second cutting line 100 battery cells 101 Pack Housing 110 Electrode assembly 111 Electrode cell body part 112 Core 112a Removal area of ​​plain area on core side, recessed area 113 First cutting line 115 Cut section 115a Cutting section 117 Forming Department 117a Uncut part 120 Battery Can 121 Battery can body 122 Supporters Section 123 Clamping part 130 First current collecting plate 132 Center hole 140 Second current collecting plate 150 Sealing cap 151 Cap Plate 152 External terminal 153 Bent Plate 155 Lead section 157 Insulator 210 First Cutter Section 211 First Blade 213 First vibration generating unit 215 1st communication hole 220 Second Cutter Section 221 Second Blade 223 Second vibration generating unit 230 Press Department 300 vehicles

Claims

1. A cutting device for cutting at least a portion of an uncoated portion of an electrode assembly including an electrode cell body portion in which a first electrode sheet, a second electrode sheet, and a separator are wound in a stacked state, and an uncoated portion that is not coated with an active material layer is provided at a width direction end of at least one of the first electrode sheet and the second electrode sheet, a first cutter that moves in the axial direction of the electrode assembly and forms a first cutting line in the axially extending uncoated portion; and a second cutter unit that moves in a radial direction of the electrode assembly, forms a second cutting line in a circumferential direction on the uncoated portion wound in the circumferential direction, and cuts out a portion of the uncoated portion surrounded by the first cutting line and the second cutting line so that the second cutting line is connected to the first cutting line, thereby forming a cut surface portion in the uncoated portion of the electrode assembly. Cutting device.

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

3. The first cutter unit further includes a first vibration generating unit.

3. The cutting device according to claim 1 or 2.

4. the second cutter unit is formed in a triangular shape with blades on two sides so as to cut a portion of the uncoated portion into a fan shape; 3. The cutting device according to claim 1 or 2.

5. The second cutter unit further includes a second vibration generating unit.

3. The cutting device according to claim 1 or 2.

6. A cutting device according to claim 1 or 2; and a press unit that presses and lays down an uncut portion from which the uncoated portion has not been cut to form a formed portion, the pressing unit moves in a radial direction of the electrode cell body unit to lay the uncut portion of the uncoated unit in the radial direction of the electrode cell body unit. Electrode assembly processing equipment.

7. a step of laminating and winding the sheet-like first electrode sheet, the second electrode sheet, and the separator to fabricate an electrode cell body; forming first cutting lines in the axial direction on the uncoated portions of the first electrode sheet and the second electrode sheet while a first cutter unit moves in the axial direction of the electrode cell body unit; a second cutter unit moving in a radial direction of the electrode cell body unit to form a second cutting line in a circumferential direction on the uncoated portion wound in the circumferential direction, and cutting out a portion of the uncoated portion surrounded by the first cutting line and the second cutting line so that the second cutting line is connected to the first cutting line, thereby forming a cut surface portion on the uncoated portion; and a press unit presses the uncut portion of the plain portion and lays it radially to form a formed portion; A method for manufacturing a battery cell.

8. The cut surface portion is formed in a fan shape along a circumferential direction around a core portion of the electrode cell body portion. The method for manufacturing the battery cell of claim 7 .

9. The cutting surface has a central angle of 60° to 120°. The method for manufacturing a battery cell according to claim 8 .

10. The forming portion is formed radially around a core portion of the electrode cell body portion. The method for manufacturing the battery cell according to any one of claims 7 to 9.

11. The forming portion is formed such that the uncut portion of the non-coating portion lies on the core portion side of the electrode cell body portion. The method for manufacturing the battery cell according to any one of claims 7 to 9.

12. The forming portion is formed along the radial direction of the electrode cell body portion. The method for manufacturing the battery cell according to any one of claims 7 to 9.

13. the cut surface portion is formed by cutting a portion spaced a predetermined distance outward in the axial direction at a boundary between the non-coating portion and the maintaining portion. The method for manufacturing the battery cell according to any one of claims 7 to 9.

14. The first cutter unit cuts the uncoated portion while being vibrated by a first vibration generating unit. The method for manufacturing the battery cell according to any one of claims 7 to 9.

15. The second cutter unit cuts the non-coating portion while being vibrated by a second vibration generating unit. The method for manufacturing the battery cell according to any one of claims 7 to 9.

16. an electrode cell body portion in which a separator is laminated between sheet-like first and second electrode sheets, the first electrode sheet, the second electrode sheet, and the separator are wound up in a jelly roll shape, and uncoated portions, which are not coated with an active material layer, are formed at one widthwise end of the first electrode sheet and the other widthwise end of the second electrode sheet; a plurality of cut surface portions formed by cutting a portion of at least one of the uncoated portion of the first electrode sheet and the uncoated portion of the second electrode sheet along a circumferential direction around a core portion of the electrode cell body portion; and a plurality of forming sections disposed between the cut surface sections and formed by pressing and laying the non-cut sections of the plain section on which the cut surface sections are formed; Electrode assembly.

17. The cut surface portion is formed in a fan shape along a circumferential direction around a core portion of the electrode cell body portion.

17. The electrode assembly of claim 16.

18. The cutting surface has a central angle of 30° to 180°.

18. The electrode assembly of claim 17.

19. The cut surface portion is formed by cutting a portion spaced a predetermined distance outward in the axial direction at a boundary between the non-coated portion where the cut surface portion is formed and the maintaining portion.

17. The electrode assembly of claim 16.

20. The forming portion is formed radially around a core portion of the electrode cell body portion.

17. The electrode assembly of claim 16.

21. The forming portion is formed in a shape in which the non-cut portion is laid on the core portion side of the electrode cell body portion.

17. The electrode assembly of claim 16.

22. The uncoated portion in which the cut surface portion is formed is removed in a predetermined section adjacent to the core portion in the winding direction.

22. The electrode assembly of claim 21.

23. the core portion is formed hollow and penetrates the center of the electrode cell body portion, and the forming portion does not obstruct the core portion in the axial direction.

17. The electrode assembly of claim 16.

24. An electrode assembly according to any one of claims 16 to 23; a battery can that houses the electrode assembly, is electrically connected to one of the first electrode sheet and the second electrode sheet, and has a first polarity; a sealing cap portion that seals the open end of the battery can; and a first current collecting plate having a second polarity electrically connected to the other of the first electrode sheet and the second electrode sheet; Battery cell.

25. The first current collecting plate is welded to the forming portion.

25. The battery cell of claim 24.

26. 26. The battery cell of claim 25, Battery pack.

27. 27. The battery pack of claim 26, vehicle.

Images