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 processing device, and a battery pack and a vehicle including the same. The present invention provides an electrode assembly 110 including a pair of cut surface portions 115 formed by cutting both diametrical sides of the uncoated portion 15 around a core portion 112 of an electrode cell body portion 111; and a forming portion 117 disposed between the pair of cut surface portions 115 and formed by applying pressure to and laying a portion to be folded 117a that is a portion of the uncoated portion 15 that is not cut out.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0046802 filed on April 9, 2021, and Korean Patent Application No. 10-2022-0040635 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 (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 structure that can further increase the electrical capacity relative to the volume of a battery cell, as well as a manufacturing method and processing apparatus for the same.

[0022] 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.

[0023] 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]

[0024] 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.

[0025] The sheets can be stacked in the order of the first electrode sheet, the separator, the second electrode sheet, and the separator.

[0026] 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.

[0027] 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.

[0028] The uncoated portion of the electrode cell body of the electrode assembly has a pair of cut surfaces formed by cutting away a portion of the uncoated portion, and the remaining uncoated portion forms a bending portion.

[0029] The cut surface portions are formed by cutting out both sides of the uncoated portion in the diameter direction around the core portion, and the portion to be folded is disposed between the pair of cut surface portions.

[0030] The electrode assembly includes one forming portion formed by bending the intended bending portion.

[0031] The cut surface portion may have an inner end portion on the core portion side formed substantially linearly and an outer end portion formed in an arc shape.

[0032] The cut surface portion may have a central angle of 150° or more and less than 180° at an inner end portion on the core portion side, and an outer end portion formed in an arc shape.

[0033] The cut surface portion may be formed by cutting a portion of the boundary between the non-coated portion and the maintaining portion, the portion being spaced a certain distance outward in the axial direction. In other words, the cut surface portion can be said to cut the non-coated portion of the maintaining portion and the non-coated portion.

[0034] The forming portion is formed along the diameter direction of the core portion.

[0035] The forming portion may be in a straight extending form.

[0036] The width of the formed portion may be substantially uniform in the circumferential direction of the electrode assembly.

[0037] The forming portion may be formed such that a width of the core portion side and a width of the outer periphery are different in the circumferential direction of the electrode assembly.

[0038] The forming portion may be formed in a shape that allows the bent portion to be laid in a radial direction of the electrode cell body portion. The bent portion may be laid on a core portion side.

[0039] By laying the forming portion, the axial length of the electrode cell body portion can be made more compact.

[0040] In other words, the axial length of the support portion of the electrode cell body housed in a battery can of the same size can be increased, thereby increasing the electrical capacity relative to the volume of the battery cell.

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

[0042] The electrode cell body portion is formed in a cylindrical shape.

[0043] In order to prevent the core portion from being blocked by the bent portion when the bent portion is laid on the core portion, the uncoated portion disposed closer to the core portion of the core portion and the outer periphery of the electrode assembly may be removed. The removal of the uncoated portion may be performed prior to the winding process.

[0044] That is, the non-coating portion may be removed from a predetermined section adjacent to the core portion in the winding direction.

[0045] 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 is formed. That is, the portion to be folded is not provided on the core side. Therefore, even if the portion to be folded is folded toward the core, the laid-down forming portion does not block the core portion of the electrode assembly.

[0046] The electrode assembly may further include a recess portion disposed on the core portion side of the uncoated portion of the electrode cell body portion and having a height that is axially recessed further than the uncoated portion disposed radially outward.

[0047] The electrode assembly may further include a plurality of cutting lines formed in the uncoated portion of the electrode cell body at a radially outer portion than the recessed portion and extending to a predetermined depth in the axial direction.

[0048] The radial width of the recessed portion may correspond to the axial height of the intended bending portion measured from a lower end of the cutting line disposed radially adjacent to the recessed portion.

[0049] The cutting depth of the cutting line may reach a predetermined portion spaced a predetermined distance outward in the axial direction at the boundary between the non-coating portion and the maintaining portion.

[0050] The recessed portion may have a height corresponding to the predetermined portion in the axial direction.

[0051] The present invention provides a battery cell including the electrode assembly.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The battery cell may further include an insulator to prevent short circuits of opposite polarities.

[0057] 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.

[0058] 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.

[0059] The present invention provides a battery pack including at least one of the battery cells.

[0060] The present invention provides a vehicle including at least one battery pack as described above.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] The first cutting line and the second cutting line may be connected to each other, so that the uncoated portion surrounded by the first cutting line and the second cutting line is cut out.

[0065] The present invention can provide a processing device including the cutting device and a press unit that performs a folding process on the portion to be folded that is cut off by the cutting device and remains.

[0066] The press unit presses and lays the portion of the plain portion to be folded, thereby forming a forming portion.

[0067] The portion to be bent may be pressed in a radial direction by the press unit, whereby the portion to be bent may be bent at a position corresponding to the second cutting line and laid out in the radial direction.

[0068] The first cutter unit may include a pair of first blades aligned with each other on the first cutter unit.

[0069] The first blade may extend in the axial direction and have a cutting edge formed at its axial tip.

[0070] The first cutter may further include a first vibration generating unit, which may generate minute vibrations.

[0071] The second cutter may be formed in a rectangular shape so as to cut a part of the uncoated portion into a semicircular shape. The tip of the second cutter may be formed in a straight line. The tip of the second cutter may be formed with a blade.

[0072] The tip of the second cutter may be formed in a shape that is inclined with respect to a center, and blades may be formed on two sides of the tip of the second cutter.

[0073] The interior angle of the tip may be an obtuse angle less than 180 degrees.

[0074] The tip may have an interior angle of 150 degrees or more.

[0075] The second cutter may further include a second vibration generating unit that generates minute vibrations.

[0076] The pressing unit may move in a radial direction of the electrode cell body unit to lay the portion of the non-coating unit to be folded onto the core unit side of the electrode cell body unit.

[0077] The present invention provides a method for manufacturing the above-mentioned battery cell.

[0078] 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.

[0079] Accordingly, the electrode assembly may include an electrode cell body portion in which the electrode sheet and the separator are wound together.

[0080] The electrode cell body portion may be cylindrical.

[0081] The electrode cell body may include a hollow core.

[0082] 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.

[0083] 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.

[0084] The non-coating portion may be removed from a predetermined section adjacent to the core portion in the winding direction.

[0085] 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.

[0086] The removal of the uncoated portion may be performed at the stage of providing an electrode sheet before constructing the electrode laminate.

[0087] 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.

[0088] The method for manufacturing the battery cell includes removing a portion of the uncoated portion provided at an axial end of the electrode cell body portion.

[0089] Specifically, the step of removing 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.

[0090] A pair of the first cutting lines may be provided, and the pair of first cutting lines may be aligned in a diameter direction.

[0091] 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 an outer periphery of the battery cell.

[0092] The second cutting lines may be provided in pairs, and may extend in a circumferential direction, and the pair of second cutting lines may be aligned in a radial direction.

[0093] The circumferential lengths of the pair of second cutting lines may gradually increase from the core side to the outer periphery side in the radial direction.

[0094] The second cutter unit cuts the uncoated portion so 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 second cutting line formed in the circumferential direction and a pair of first cutting lines respectively connected to both ends of the second cutting line.

[0095] The cut surface portions formed at the positions where the uncoated portions are cut may be formed in semicircular shapes on both sides of the core portion.

[0096] The cut surface portion may have an inner end portion on the core portion side formed in a straight line and an outer end portion formed in an arc shape.

[0097] The cut surface portion may have a central angle of 150° or more and less than 180° at an inner end portion on the core portion side, and an outer end portion formed in an arc shape.

[0098] The method for manufacturing the battery cell may further include forming a forming portion by bending a portion to be folded, which is a portion of the uncoated area remaining after being cut along the cutting line, in a radial direction and laying it down.

[0099] The bending process can be performed by pressing the portion to be bent in the radial direction with a press unit.

[0100] The formed portions may be formed uniformly in the diameter direction of the electrode cell body portion.

[0101] The forming portion may be formed such that a portion of the non-coating portion to be folded is disposed on a core portion side of the electrode cell body portion.

[0102] 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.

[0103] The first cutter may cut the non-coating portion while being vibrated by a first vibration generating unit. The first cutter may be an ultrasonic cutter.

[0104] The second cutter may cut the non-coating portion while being vibrated by a second vibration generating unit. The second cutter may be an ultrasonic cutter. [Effects of the Invention]

[0105] 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.

[0106] 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.

[0107] According to the present invention, after the portion to be cut and the portion to be folded in the plain portion are separated from each other, the portion to be cut is cut to form a cut surface portion, and the portion to be folded is pressed and laid to form a formed portion. This prevents the boundary between the formed portion and the cut surface portion from being torn or irregularly distorted and deformed when the portion to be folded is pressed to form the formed portion.

[0108] According to the present invention, the boundary between the forming portion and the cut surface portion can be prevented from being torn or deformed, thereby preventing contact with an electrode sheet of the opposite polarity at the torn or deformed portion.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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]

[0113] [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 schematically showing the electrode cell stack of FIG. 1 cut in the AA direction. [Figure 3] 2 is a perspective view schematically 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] FIG. 2 is a perspective view schematically showing a state in which a first embodiment of a first cutter portion according to the present invention has cut an electrode cell body portion. [Figure 5] FIG. 1 is a plan view showing a first embodiment of a first cutter unit according to the present invention. [Figure 6] 4 is a plan view schematically showing a state in which a first cutter portion according to the present invention has cut an electrode cell body portion. FIG. [Figure 7] FIG. 10 is a plan view showing a second embodiment of a first cutter unit according to the present invention. [Figure 8] FIG. 10 is a plan view schematically showing a state in which a second embodiment of a first cutter unit according to the present invention has cut an electrode cell body portion. [Figure 9] 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. FIG. [Figure 10] 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 11] 10 is a perspective view showing a state in which a press unit presses a portion to be folded in a state in which a second cutter unit cuts an uncoated portion of an electrode cell body according to the present invention. FIG. [Figure 12] 10 is a perspective view showing a state in which a press unit presses a portion to be bent according to the present invention to form a formed portion. FIG. [Figure 13] 10 is a side view showing a state in which a press unit according to the present invention has formed a forming portion that presses a portion to be bent. FIG. [Figure 14] 3 is a flowchart illustrating a method for manufacturing a battery cell according to the present invention. [Figure 15] 1 is a cross-sectional view showing an electrode assembly according to the present invention; [Figure 16] 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 17] 1 is a perspective view showing a state in which a battery pack according to the present invention is installed in a vehicle; DETAILED DESCRIPTION OF THE INVENTION

[0114] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] Hereinafter, an electrode assembly according to an embodiment of the present invention will be described.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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 tap. 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.

[0127] 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.

[0128] 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.

[0129] The first electrode sheet 11 and the second electrode sheet 12 each include a current collector (not shown) made of metal foil and an active material layer (not shown). 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] The binder polymer usable in the electrode sheets 11 and 12 is a component that helps bind the electrode active material particles with the conductive material and the like and 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 ...

[0141] 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.

[0142] 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.

[0143] The porous polymer substrate may be a polyolefin-based porous substrate.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] An electrode assembly 110 manufactured using the electrode stack 10 described above will now be described.

[0152] FIG. 4 is a perspective view showing a state in which a first embodiment of a first cutter unit according to the present invention has cut an electrode cell body portion, FIG. 5 is a plan view showing a first embodiment of a first cutter unit according to the present invention, FIG. 6 is a plan view showing a state in which a first cutter unit according to the present invention has cut an electrode cell body portion, FIG. 7 is a plan view showing a second embodiment of a first cutter unit according to the present invention, FIG. 8 is a plan view showing a state in which a second embodiment of a first cutter unit according to the present invention has cut an electrode cell body portion, FIG. 9 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 portion, and FIG. 10 is a side 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. Figure 11 is an oblique view showing a state in which a second cutter unit according to the present invention has cut the plain portion of an electrode cell body unit and a press unit presses the portion to be bent, Figure 12 is an oblique view showing a state in which a press unit according to the present invention has pressed the portion to be bent to form a formed portion, and Figure 13 is a side view showing a state in which a press unit according to the present invention has formed a formed portion by pressing the portion to be bent.

[0153] 4 to 13, 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.

[0154] 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.

[0155] The electrode cell body 111 can be formed by winding the electrode stack 10, which extends longitudinally, around a winding rod (not shown) and then 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 stack 10, the more the winding time and manufacturing time for the electrode assembly 110 can be shortened. The area where the winding rod is removed from the electrode cell body 111 forms a hollow core 112.

[0156] 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.

[0157] 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.

[0158] 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 to be folded 117a in the circumferential direction. A first cutting line 113 is formed between the portion to be cut 115a and the portion to be folded 117a. The first cutting line 113 is formed in a shape extending in the axial direction (vertical shape) from the axial end of the uncoated portion 15 toward the electrode cell body portion 111. At this time, the portion to be cut 115a and the portion to be folded 117a maintain a standing state along the axial direction of the electrode cell body portion 111.

[0159] The second cutter unit 220 radially cuts the axially lower portion of the portion to be cut 115a of the uncoated 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 uncoated 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 uncoated portion 15 and are provided below the uncoated portion portions arranged adjacent to each other in the radial direction. The second cutting lines 16a When both circumferential ends of the cut portion 115a are connected to the first cutting lines 13 on both sides of the cut portion 115a in the circumferential direction, the pair of first cutting lines 13 and second cutting lines 16a The cut portion 115a surrounded by the arrow is separated from the electrode cell body portion 111. The short uncoated portion remaining after the cut portion 115a is cut forms the cut surface portion 115.

[0160] As a result, the uncoated portion 15 of the electrode cell body portion 111 is provided with a cut surface portion 115 and a portion to be folded 117a.

[0161] The first cutter unit 210 for cutting the first cutting line 113 may be an ultrasonic cutter to prevent buckling that may occur when cutting the thin plain portion 15 in the axial direction.

[0162] The first cutter unit 210 includes a pair of first blades 211 aligned on both sides of a position corresponding to the diameter portion of the electrode cell body unit 111, and a pair of first vibration generating units 213 to which the first blades 211 are respectively fixed.

[0163] One first blade 211 is fixed to each of the first vibration generating parts 213 .

[0164] The first vibration generating unit 213 includes a plate and a vibration source for vibrating the plate. The plate may be formed in a rectangular shape.

[0165] The first blade 211 may have its base end fixed to the surface of the plate of the first vibration generating part 213, extend in a direction corresponding to the axial direction of the electrode cell body part 110, and have a sharp cutting edge at its tip.

[0166] The pair of first blades 211 are arranged symmetrically with respect to the diameter of the electrode cell body 110 on the first vibration generating part 213. An embodiment relating to this will be described as follows.

[0167] 4 to 6, a pair of first blades 211 defining the intended bending portion 117a may be linearly arranged on both sides of the diameter of the electrode cell body portion 210 based on the diameter portion of the electrode cell body portion 210. In this case, the pair of first blades 211 are arranged at the same distance from the diameter portion of the electrode cell body portion 210. As a result, when the pair of first blades 211 cut the uncoated portion 15 of the electrode cell body portion 210, linear first cutting lines 113 can be formed on both sides of the diameter portion of the uncoated portion 15.

[0168] In the above embodiment, a structure is illustrated in which the pair of first blades 211 defining the intended bending 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 have to be linear. For example, the first blades 211 may be gently curved.

[0169] Furthermore, in the above embodiment, a structure has been exemplified in which the pair of first blades 211 that define the intended bending portion 117a are fixed to the pair of first vibration generating parts 213, respectively. However, the pair of first blades 211 may be fixed to one first vibration generating part 213 together.

[0170] In addition, in the above embodiment, a method in which the pair of first blades 211 defining the bending portion 117a simultaneously cut the uncoated portion is illustrated, but this does not exclude a method in which one first blade 211 first processes one of the two sides of the diameter portion of the electrode cell body portion 210 and then processes the other.

[0171] Furthermore, in the above embodiment, the first blade 211 is exemplified as being a single blade extending continuously in a straight line, but it is also acceptable for the blade to be discontinuous in sections where the plain portion is not cut anyway (for example, the core section).

[0172] 7 and 8, the pair of first blades 211 are disposed in a shape inclined at a certain angle based on the diameter of the electrode cell body portion 210. In this case, the outer inclination angle (θ2) of the first blades 211 may be formed to be equal to or greater than 150° and less than 180°. As a result, when the pair of first blades 211 cut the uncoated portion 15 of the electrode cell body portion 210, it is possible to form first cutting lines 113 inclined on both sides of the diameter of the uncoated portion 15.

[0173] Of course, the outer inclination angle (θ2) of the first blades 211 may be greater than 180° and less than or equal to 210°. The angle of the pair of first blades 211 can be appropriately selected depending on the diameter of the electrode cell body portion 111, the capacity of the battery pack, and the shapes of the current collecting plates 130, 140 to be welded thereto.

[0174] In the above embodiment, the pair of first blades 211 defining the intended bending portion 117a are symmetrically inclined relative to each other with respect to the center of the core portion 112. However, the pair of first blades 211 do not necessarily have to be formed in a symmetrically inclined structure with respect to the center of the core portion 112. For example, the pair of first blades 211 may be formed at angles that differ as they move from the center of the core portion 112 toward the centripetal position. Furthermore, although the first blades 211 are exemplified as being linear, the first blades 211 do not necessarily have to be linear. For example, the first blades 211 may be gently curved on the core portion 112 side or the opposite side.

[0175] The first vibration generating unit 213 may include an ultrasonic vibrator. The first vibration generating unit 213 generates ultrasonic vibrations when the first blade 211 moves in the axial direction of the electrode cell body portion 111 and cuts the non-coating portion 15.

[0176] If the force of the first blade 211 pressing the uncoated portion 15 in the axial direction is not used to process the first cutting line 113 but is used to press the uncoated portion 15, there is a possibility that the uncoated portion 15 may buckle or the portion of the uncoated portion 15 near the first cutting line 113 may be warped or broken, resulting in deformation.

[0177] 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 allows the first cutting line 113 to be formed smoothly 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.

[0178] 9 to 11, 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.

[0179] The second blade 221 may have a linear tip. In this case, the tip may be provided with a cutting edge. When the second blade 221 having such a linear tip cuts the second cutting line 16a of the portion to be cut 115a, the portion to be folded 117a is aligned in a straight line with the diameter direction of the electrode cell assembly 110, as shown in FIG. 11 . The cut surface portion 115 has an inner end 115b on the core portion 112 side formed in a straight line and an outer end 115c formed in an arc shape. The inner end 115b forms a boundary between the portion to be folded 117a and the cut surface portion 115. The outer end 115c is positioned on the outer peripheral surface of the electrode cell body portion 111.

[0180] The tip of the second blade 221 may be inclined on both sides of its center. In this case, the central angle of the tip of the second blade 221 is greater than or equal to 150° and less than 180°. The second blade 221 may be double-edged. That is, blades may be provided at positions corresponding to two oblique sides extending from the tip. When the second blade 221 having such an inclined tip cuts the second cutting line 16a of the portion to be cut 115a, as shown in FIG. 8, the width of the portion to be bent 117a is narrower on the central side than on the outer periphery side. In addition, the central angle (θ1) of the inner end of the cut surface portion 117a on the core portion 112 side is greater than or equal to 150° and less than 180°, and the outer end is formed in an arc shape. In addition, the outer end of the cut surface portion 117a is formed in an arc shape. The inner end portion 115b forms a boundary line between the intended bending portion 117a and the cut surface portion 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode cell body portion 111.

[0181] Of course, the central angle of the tip of the second blade 221 may be formed to be greater than 180° and equal to or less than 210°.

[0182] The central angle of the tip of the second blade 221 is formed at the same angle as the central angle (θ2: see FIG. 7) of the first blade 211. As a result, the first blade 211 moves axially to form the first cutting line 113 in the diameter direction in the uncoated portion 15, and when the second blade 221 cuts the second cutting line 16a of the portion to be cut 115a in the radial direction so as to contact the first cutting line 113, nearly semicircular cut surface portions 115 are formed on both sides of the linear portion to be bent 117a.

[0183] As the second blade 221 advances radially to form the second cutting line 16a, the pointed tip of the second blade 221 first cuts the circumferential center of the portion to be cut 115a of the uncoated portion 15, and as the second blade 221 advances centripetally, both edges expand the second cutting line 16a to both sides in the circumferential direction. When the second blade 221 applies force to the side of the uncoated portion 15 in the radial direction, the force is concentrated at the pointed tip and applied to the uncoated portion 15 without a wide area of the second blade 221 coming into contact with the side of the uncoated portion 15 at once. Therefore, when the second cutting line 16a is formed on the side of the uncoated portion 15, the uncoated portion 15 is not pressed sideways and deformed. After the tip cuts through the non-coated portion 15, the second cutter unit 220 moves in a centripetal direction, and both blades of the second cutter unit 220 apply pressure to the second cutting line 16a in the circumferential direction to cut it. The cutting method and direction of the second cutter unit 220 minimize deformation of the non-coated portion 15.

[0184] The tip of the second blade 221 described above may be formed in a shape corresponding to that of the first blade 211. For example, if the first blade 211 is formed in a straight line, the tip of the second blade 221 may also be formed in a straight line. Also, if the first blade 211 is formed at an angle, the tip of the second blade 221 may also be formed at an angle. If the first blade 211 is formed in a rounded shape, the tip of the second blade 221 may also be formed in a rounded shape.

[0185] 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 portion 111 and cuts the uncoated portion 15. This may improve the cutting speed of the uncoated portion 15 and form a smooth cut surface portion 115. The second vibration generating unit 223 may use various vibration methods as long as it vibrates the second blade 221.

[0186] 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 to surround the core portion 112. The radial width (W2) of the recess 112a may be the same as, slightly wider than, or narrower than the height (W1) of the uncoated portion 15 (see FIGS. 9 and 10). The recess 112a is formed concentrically with the core portion 112. The recess 112a may be flush with the cut surface portion 115 or slightly lower than the cut surface portion 115.

[0187] The pair of cutting lines 113 may be provided in a radially outer position than the recessed portion 112a in the uncoated portion 15 of the electrode cell body portion 111, and may be formed to a predetermined depth in the axial direction.

[0188] The radial width of the recessed portion 112a may correspond to the axial height of the intended bending portion 117a measured from the lower end of the cutting line 113 disposed radially adjacent to the recessed portion 112a.

[0189] The cutting depth of the cutting line 113 may reach a predetermined portion at a boundary 16 between the non-coating portion 15 and the maintaining portion 14, the predetermined distance being spaced apart from the boundary 16 in the axial direction.

[0190] The recessed portion 112a may have a height corresponding to the predetermined portion in the axial direction.

[0191] The formed portion 117 is formed by pressing and laying the to-be-folded portion 117a of the uncoated portion 15, which is disposed between a pair of cut surface portions 115, in a direction intersecting the axial direction, for example, in a radial direction. The formed portion 117 may be formed by pressing and laying the to-be-folded portion 117a of the uncoated portion 15 using a press unit 230, which will be described later. In this case, the formed portion 117 may be formed by laying down a plurality of uncut pieces that form the to-be-folded portion 117a, in a continuous overlapping manner. As a result, the formed portion 117 may be formed inclined with respect to the axial direction of the electrode cell body portion 111, or may be completely laid down and flat.

[0192] The forming portions 117 are formed to have the same width. For example, when the tip portions of the first blade 211 and the second blade 221 are formed in a straight line, the forming portions 117 may be formed to have the same width.

[0193] Furthermore, the forming portion 117 may be formed so that its width on the core portion 112 side is different from its outer width. For example, when the central angle (θ2: see FIG. 7) of the first blade 211 and the tip end of the second blade 221 are formed to be inclined, the forming portion 117 is formed so that its width on the core portion 112 side is different from its outer width.

[0194] The forming portion 117 is a portion welded to the current collecting plates 130 and 140 to form a current path. Furthermore, the pair 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 (by welding or laser welding) to the current collecting plates 130 and 140 while being in line contact with the current collecting plates 130 and 140, the cut surface portions 115 do not have much effect in increasing the current path when provided with the forming portion 117. Meanwhile, since the forming portion 117 is formed by laying the intended folding portions 117a in the radial direction, the forming portion 117 covers the gap 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 a state of being bonded thereto, and therefore, as the area of the forming portions 117 increases, the current path between the electrode assembly 110 and the current collecting plates 130 and 140 can relatively increase. These forming portions 117 increase the area of the current path by the combined distance between the uncoated portions 15, and therefore, even when applied to a large-capacity battery cell 100, the increase in heat generation of the battery cell 100 can be suppressed, thereby reducing the possibility of fire.

[0195] 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 110. Although the impregnation of the electrolyte may be weakened in the area of the forming portion 117 due to the bending of the uncut pieces, the cut surface portion 115, adjacent to the forming portion 117, compensates for this, so there is no particular problem with the impregnation of the electrolyte.

[0196] According to the present invention, the portion to be cut 115a and the portion to be folded 117a in the plain portion 15 are separated in the diameter direction by the first cutter unit 210, which forms a pair of first cutting lines 113 in the axial direction, and then the lower end of the portion to be cut 115a is cut by the second cutter unit 220 to form the cut surface portion 115, and the portion to be folded 117a is pressurized and laid down to form the formed portion 117. This prevents the boundary portion 16 between the formed portion 117 and the cut surface portion 115 from being torn or deformed irregularly when pressurizing the portion to be folded 117a to form the formed portion 117.

[0197] Furthermore, since the boundary 16 between the forming portion 117 and the cut surface portion 115 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, thereby preventing a weakening of the bonding strength. As a result, a decrease in the performance and capacity of the battery cell 100 can be suppressed.

[0198] 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.

[0199] Furthermore, since the forming portion 117 is formed by pressing the to-be-folded portion 117a with the cut surface portions 115 removed from both sides of the to-be-folded portion 117a, it is possible to prevent the uncut portion of the to-be-folded portion 117a from tilting and standing up due to a spring back phenomenon. Furthermore, when the to-be-folded portion 117a is pressed with a strong pressure using the press unit 230, the forming portion 117 (the uncut portion of the to-be-folded portion 117a) can be superimposed on the cut surface portion 115 in a state of being as flat and in close contact as possible. As a result, the forming portion 117 and the cut surface portion 115 are welded to the current collecting plates 130 and 140 in surface contact, thereby significantly increasing the weld cross-sectional area. Furthermore, the increased 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.

[0200] 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.

[0201] The central angle (θ1: see FIG. 8 ) 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 150°. This is because, as the diameter of the electrode cell body portion 111 increases, the enlarged cross-sectional area of the current path is advantageous for preventing heat generation and fire, so the central angle (θ1) 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 150°.

[0202] The forming portion 117 may be formed in a shape such that the intended folding portion 117a of the non-coating 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, thereby allowing the electrode assembly 110 to 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.

[0203] When the intended bending portion 117a is laid on the core portion 112 side of the electrode cell body portion 111, a phenomenon of separating the core portion 112 may occur when the intended bending portion 117a adjacent to the core portion 112 is laid. That is, as shown in FIG. 1(a), when the uncoated portion 15 adjacent to the core portion 112 is laid without cutting a portion of the uncoated portion 15, the forming portion 117 may block the core portion 112.

[0204] 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 (C) of the uncoated portion 15 located on the core portion 112 side is pre-cut, and the electrode assembly 110 is fabricated as described above, a recessed portion 112a is formed by removing the uncoated portion 15 adjacent to the core portion 112, as shown in FIG. 11. When the forming portion 117 is formed in this state, the innermost portion of the intended bending portion 117a overlaps the recessed portion 112a, as shown in FIG. 12, and the core portion 112 is not obstructed.

[0205] 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.

[0206] 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.

[0207] Next, a method for manufacturing a battery cell according to the present invention will be described.

[0208] FIG. 14 is a flow chart illustrating a method for manufacturing a battery cell according to the present invention.

[0209] 14, 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.

[0210] 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.

[0211] 1(b) can be performed after the electrode stacking step (S11) and before the winding step (S12). This may be a process in which a portion of the uncoated portion 15 is cut and removed by laser cutting.

[0212] The depth to which the non-coating portion 15 in the predetermined section (C) is removed and the depth of the cutting line 113 may correspond to each other.

[0213] 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 to surround the core portion 112. The radial width (W2) of the recess 112a may be the same as, or slightly wider or narrower than, the height (W1) of the uncoated portion 15 (see FIGS. 9 and 10). The recess 112a is formed concentrically with the core portion 112. The recess 112a may be flush with the cut surface portion 115 or slightly lower.

[0214] The first cutter unit 210 moves in the axial direction of the battery cell 100 and cuts the uncoated portions 15 of the first electrode sheet 11 and the second electrode sheet 12 in the diametrical direction (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 to be folded 117a. A pair of first cutting lines 113 is formed between the portion to be cut 115a and the portion to be folded 117a in the diametrical direction. At this time, the portion to be cut 115a and the portion to be folded 117a maintain a standing state along the axial direction of the electrode cell body portion 111.

[0215] The second cutter unit 220 moves in the radial direction of the battery cell 100 and cuts the non-coating portion 15 along the second cutting line to form the cut surface portion 115 (S14). The second cutter unit 220 cuts the non-coating portion 15 along the radial direction to remove it from the electrode cell body portion 111. As a result, the non-coating portion 15 of the electrode cell body portion 111 has the bent portion 117a arranged in a straight line in the diameter direction. In addition, the cut surface portion 115 is formed in a semicircular shape on both sides of the bent portion 117a.

[0216] The press unit 230 applies pressure to the bent portion 117a of the non-coated portion 15 and lays it down, thereby forming the formed portion 117 (S15). The formed portion 117 is disposed between the cut surface portions 115 and is formed by applying pressure to the bent portion 117a of the non-coated portion 15 and laying it down. The formed portion 117 may be formed by applying pressure to the bent portion 117a of the non-coated portion 15 and laying it down using the press unit 230 described below. At this time, multiple uncut pieces that form the bent portion 117a may be laid down 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.

[0217] 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 significantly increase the current path. Meanwhile, the forming portions 117 are formed by radially extending the intended bending 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 possibility of fire.

[0218] After the portions to be cut 115a and the portions to be folded 117a in the plain portion 15 are separated from each other, the portions to be cut 115a are cut to form the cut surface portion 115, and the portions to be folded 117a are pressed and laid down to form the formed portion 117. This prevents the boundary portion 16 between the formed portion 117 and the cut surface portion 115 from being torn or deformed irregularly when the portions to be folded 117a are pressed to form the formed portion 117.

[0219] 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.

[0220] The cut surface portions 115 may be formed in a semicircular shape on both sides of the forming portion 117 of the electrode cell body portion 111. Since the cut surface portions 115 are formed in a semicircular shape, one forming portion 117 may be disposed radially between the pair of cut surface portions 115.

[0221] The cut surface portion 115 has an inner end 115b on the core portion 112 side formed in a straight line and an outer end 115c formed in an arc shape. The inner end 115b forms a boundary between the intended bending portion 117a and the cut surface portion 115. The outer end 115c is disposed on the outer peripheral surface of the electrode cell body portion 111.

[0222] The cut surface portion 117a has an inner end portion on the core portion 112 side formed with a central angle (θ1) of 150° or more and less than 180°, and an outer end portion formed in an arc shape. The outer end portion of the cut surface portion 117a is also formed in an arc shape. The inner end portion 115b forms a boundary between the portion to be bent 117a and the cut surface portion 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode cell body portion 111.

[0223] Furthermore, the cut surface portion 117a may be formed so that the central angle (θ1) of the inner end portion on the core portion 112 side is greater than 180° and less than 210°, and the outer end portion is formed in an arc shape.

[0224] Furthermore, the cut surface portion 117a may have an inner end portion on the core portion 112 side formed in a round shape, and an outer end portion formed in an arc shape.

[0225] The cut surface portion 115 may be formed by cutting a portion 16a that is spaced a certain distance (H: see FIG. 10) 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, which can prevent the active material coated on the supporting portion 14 from being detached.

[0226] Furthermore, even if the non-coating portion 15 is cut while being slightly deformed, the maintaining portion 14 can be prevented from being damaged or deformed.

[0227] The forming portion 117 may be formed in a shape in which the intended folding portion 117a of the non-coating 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.

[0228] The formed portion 117 is formed by pressing and laying the to-be-folded portion 117a of the uncoated portion 15, which is disposed between a pair of cut surface portions 115, in a direction intersecting the axial direction, for example, in a radial direction. The formed portion 117 may be formed by pressing and laying the to-be-folded portion 117a of the uncoated portion 15 using a press unit 230. In this case, the formed portion 117 may be formed by laying a plurality of uncut pieces forming the to-be-folded portion 117a in a continuous overlapping manner. As a result, the formed portion 117 may be formed inclined with respect to the axial direction of the electrode cell body portion 111, or may be completely laid flat.

[0229] The forming portions 117 are formed to have the same width. For example, when the tip portions of the first blade 211 and the second blade 221 are formed in a straight line, the forming portions 117 may be formed to have the same width.

[0230] In addition, the forming portion 117 may be formed so that its width on the core portion 112 side is different from its outer width. For example, when the central angle (θ2: see FIG. 7) of the first blade 211 and the tip of the second blade 221 are formed to be inclined, the forming portion 117 is formed so that its width on the core portion 112 side is different from its outer width.

[0231] 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 first cutter unit 210 cuts the uncoated portion 15 while vibrating, the cutting performance and cutting speed of the uncoated portion 15 can be improved.

[0232] 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.

[0233] It is preferable that the above-mentioned cutting surface portion 115 is processed by the first cutter portion 210 first, and then by the second cutter portion 220.

[0234] A battery cell manufactured using the above electrode assembly will now be described.

[0235] FIG. 15 is a cross-sectional view showing an electrode assembly according to the present invention.

[0236] Referring to FIG. 15, 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 .

[0237] The electrode assembly 110 is substantially the same as that described above, and therefore, a description thereof will be omitted.

[0238] 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 materials including stainless steel and aluminum. The battery can 120 may be formed in a cylindrical shape with an open end on one side (the upper side in FIG. 15 ).

[0239] 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.

[0240] 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.

[0241] 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.

[0242] An electrolyte solution is poured into the battery can 120 through the core portion 112 of the electrode assembly 110 .

[0243] 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:

[0244] 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.

[0245] 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.

[0246] The insulator 157 may be made of an insulating polymer resin, such as polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0247] 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).

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] 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.

[0254] 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 .

[0255] FIG. 16 is a perspective view showing the electrode assembly according to the present invention housed in a pack housing.

[0256] 16, 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) for electrically connecting the cylindrical battery cells 100, a cooling unit (not shown), and external terminals (not shown) are omitted from the drawings.

[0257] 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.

[0258] FIG. 17 is a diagram illustrating a vehicle including a battery pack according to the present invention.

[0259] 17, 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.

[0260] 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]

[0261] 210 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 Recessed part 113 First cutting line 115 Cut section 115a Cutting section 117 Forming Department 117a Bending section 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 15 of an electrode assembly 110 in which a first electrode sheet 11, a second electrode sheet 12, and a separator 13 are wound in a stacked state, and an uncoated portion 15 is provided at a width direction end of at least one of the first electrode sheet 11 and the second electrode sheet 12, where the uncoated portion is not coated with an active material layer, a first cutter unit (210) that moves in the axial direction of the electrode assembly (110) and cuts the axially extending uncoated portion (15) in the axial direction to form a pair of first cutting lines (113) aligned in the diameter direction of the uncoated portion (15); and a second cutter unit (220) that moves in a radial direction of the electrode assembly (110) to form a pair of second cutting lines (16a) in a circumferential direction on the uncoated portion (15) wound in a circumferential direction, and cuts out the uncoated portion surrounded by the first cutting lines (113) and the second cutting lines (16a) so that the pair of second cutting lines (16a) are connected to the first cutting lines (113), respectively, thereby forming a pair of cut surface portions (115) outside the pair of first cutting lines (113) of the uncoated portion (15); Cutting device.

2. The first cutter unit 210 includes a pair of first blades 211 disposed on both diametrical sides of the non-coating portion 15 and extending in the axial direction. The cutting device according to claim 1 .

3. The first cutter unit 210 further includes a first vibration generating unit 213.

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

4. The second cutter unit 220 is formed in a square shape with a blade at its end so as to cut the outside of the first cutting line 113 of the non-coating portion 15.

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

5. The second cutter unit 220 further includes a second vibration generating unit 223.

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

6. A cutting device according to claim 1 or 2; and a press unit (230) for pressing and laying the bent portion (117a) where the uncoated portion (15) is not cut off to form the formed portion (117), The pressing unit 230 is moved in the radial direction of the electrode assembly 110 to lay the bending portion 117a between the pair of first cutting lines 113 of the non-coating portion 15 in the radial direction of the electrode assembly 110. Electrode assembly processing equipment.

7. A method for manufacturing a battery cell 100, comprising: a step of stacking and winding the sheet-like first electrode sheet 11, the second electrode sheet 12, and the separator 13; a first cutter unit (210) moving in an axial direction of the battery cell (100) to cut the uncoated portions (15) of the first electrode sheet (11) and the second electrode sheet (12) in an axial direction to form a pair of first cutting lines (113); a second cutter unit (220) moving in a radial direction of the battery cell (100) to form a pair of second cutting lines (16a) in a circumferential direction on the non-coating portion (15) wound in a circumferential direction, and cutting out a portion of the non-coating portion surrounded by the first cutting lines (113) and the second cutting lines (16a) while the pair of second cutting lines (16a) is connected to the first cutting lines (113), thereby forming cut surface portions (115) outside the pair of first cutting lines (113) of the non-coating portion (15); and a press unit (230) pressing the bent portion (117a) between the pair of first cutting lines (113) of the non-coating portion (15) and laying it in a radial direction to form a formed portion (117); A method for manufacturing a battery cell 100.

8. The cut surface portion 115 has an inner end 115b on the core portion 112 side of the battery cell 100 formed in a straight line shape, and an outer end 115c formed in an arc shape. The method for manufacturing the battery cell 100 according to claim 7 .

9. The cut surface portion 115 has an inner end portion 115b on the core portion 112 side of the battery cell 100, the central angle (θ1) of which is equal to or greater than 150° and less than 180°, and an outer end portion 115c is formed in an arc shape. The method for manufacturing the battery cell 100 according to claim 7 .

10. The forming portion 117 is formed along a diameter direction around the core portion 112 of the battery cell 100. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

11. The width of the forming portion 117 is formed to be the same. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

12. The forming portion 117 is formed such that the width of the core portion 112 side of the battery cell 100 is different from the width of the outer periphery. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

13. The forming portion 117 is formed to extend from both sides of the outer periphery of the forming portion 117 toward the core portion 112 of the battery cell 100. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

14. The cut surface portion 115 is formed by cutting a portion spaced a predetermined distance outward in the axial direction at the boundary portion 16 between the non-coating portion 15 and the maintaining portion 14. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

15. The first cutter unit 210 cuts the non-coating portion 15 while being vibrated by a first vibration generating unit 213. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

16. The second cutter unit 220 cuts the non-coating portion 15 while being vibrated by a second vibration generating unit 223. A method for manufacturing the battery cell 100 according to any one of claims 7 to 9.

17. an electrode cell body part (111) in which a sheet-like first electrode sheet (11), a second electrode sheet (12), and a separator (13) are laminated and wound up in a jelly roll shape, and a plain part (15) in which an active material layer is not coated is formed on an end part in the width direction of at least one of the first electrode sheet (11) and the second electrode sheet (12); A pair of cut surface portions 115 formed by cutting out both sides of the uncoated portion 15 in the diametric direction around the core portion 112 of the electrode cell body portion 111; and a forming portion 117 disposed between the pair of cut surface portions 115 and formed by pressing and laying a portion to be folded 117a, which is a portion of the plain portion 15 that has not been cut out; The electrode cell body 111 further includes a recess 112a disposed on the core 112 side of the uncoated portion 15 and having a height that is axially recessed relative to the uncoated portion 15 disposed radially outward therefrom. Electrode assembly 110.

18. The cut surface portion 115 has an inner end portion 115b on the core portion 112 side formed in a straight line, and an outer end portion 115c formed in an arc shape.

18. The electrode assembly 110 of claim 17.

19. An electrode cell body portion (111) in which a sheet-like first electrode sheet (11), a second electrode sheet (12), and a separation membrane (13) are laminated and wound up in a jelly roll shape, and a plain portion (15) that is not coated with an active material layer is formed at the widthwise end of at least one of the first electrode sheet (11) and the second electrode sheet (12); A pair of cut surface portions 115 formed by cutting out both sides of the uncoated portion 15 in the diametric direction around the core portion 112 of the electrode cell body portion 111; and a forming portion 117 disposed between the pair of cut surface portions 115 and formed by pressing and laying a portion to be folded 117a, which is a portion of the plain portion 15 that has not been cut out; The cut surface portion 115 has an inner end portion 115b on the core portion 112 side formed with a central angle (θ1) of 150° or more and less than 180°, and an outer end portion 115c formed in an arc shape. Electrode assembly 110.

20. The forming portion 117 is formed along the diameter direction of the core portion 112.

18. The electrode assembly 110 of claim 17.

21. The width of the forming portion 117 is formed to be uniform.

18. The electrode assembly 110 of claim 17.

22. An electrode cell body portion (111) in which a sheet-like first electrode sheet (11), a second electrode sheet (12), and a separation membrane (13) are laminated and wound up in a jelly roll shape, and a plain portion (15) in which an active material layer is not coated is formed at the widthwise end portion of at least one of the first electrode sheet (11) and the second electrode sheet (12); A pair of cut surface portions 115 formed by cutting out both sides of the uncoated portion 15 in the diametric direction around the core portion 112 of the electrode cell body portion 111; and a forming portion 117 disposed between the pair of cut surface portions 115 and formed by pressing and laying a portion to be folded 117a, which is a portion of the plain portion 15 that has not been cut out; The forming portion 117 is formed such that the width of the core portion 112 side and the width of the outer periphery are different. Electrode assembly 110.

23. The forming portion 117 is formed in a shape such that the intended bending portion 117a is laid in the radial direction of the electrode cell body portion 111.

18. The electrode assembly 110 of claim 17.

24. The forming portion 117 is formed in a shape that extends from both sides of the outer periphery of the forming portion 117 toward the core portion 112.

18. The electrode assembly 110 of claim 17.

25. The cut surface portion 115 is formed by cutting a portion spaced a predetermined distance outward in the axial direction at the boundary portion 16 between the non-coating portion 15 and the maintaining portion 14.

18. The electrode assembly 110 of claim 17.

26. The core portion 112 is formed in a hollow shape that penetrates the center of the electrode cell body portion 111.

18. The electrode assembly 110 of claim 17.

27. The electrode cell body portion 111 is formed in a cylindrical shape.

18. The electrode assembly 110 of claim 17.

28. The electrode cell body portion 111 further includes a pair of cutting lines 113 formed radially outward from the recessed portion 112a in the uncoated portion 15 of the electrode cell body portion 111 and extending to a predetermined depth in the axial direction.

18. The electrode assembly 110 of claim 17.

29. The radial width of the recessed portion 112a corresponds to the axial height of the intended bending portion 117a measured from the lower end of the cutting line 113 disposed radially adjacent to the recessed portion 112a.

29. The electrode assembly 110 of claim 28.

30. The cutting depth of the cutting line 113 reaches a predetermined portion at a predetermined distance outward in the axial direction at the boundary portion 16 between the non-coating portion 15 and the maintaining portion 14.

29. The electrode assembly 110 of claim 28.

31. The recessed portion 112a has a height corresponding to the predetermined portion in the axial direction.

31. The electrode assembly 110 of claim 30.

32. An electrode assembly 110 according to any one of claims 17 to 31; a battery can 120 having a first polarity, in which the electrode assembly 110 is accommodated and which is electrically connected to either the first electrode sheet 11 or the second electrode sheet 12; A sealing cap portion 150 that seals the open end of the battery can 120; and a first current collecting plate 130 having a second polarity, electrically connected to the other of the first electrode sheet 11 and the second electrode sheet 12; Battery cell 100.

33. an insulator 157 interposed between the outer periphery of the sealing cap 150 and the inner periphery of the battery can 120 and between the sealing cap 150 and the first current collecting plate 130; 33. The battery cell 100 of claim 32.

34. 33. The battery cell according to claim 32, Battery pack.

35. 35. The battery pack of claim 34, vehicle.

Images