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

Abstract

This invention discloses an electrode assembly, a battery cell, a processing apparatus thereof, a battery pack comprising the same, and a vehicle. The invention provides an electrode assembly (110) comprising: a pair of cut surfaces (115) formed by cutting off two sides in the diameter direction of an uncoated portion (15) centered on a core portion (112) of an electrode cell body portion (111); and a forming portion (117) disposed between the pair of cut surfaces (115), wherein the portion of the uncoated portion (15) not cut off, i.e., the intended bending portion (117a), is pressed down to form the forming portion (117).

Description

Technical Field

[0001] The present invention relates to an electrode assembly, a cutting device and a bending device for the uncoated portion of the electrode assembly, a battery cell including the electrode assembly, a battery pack including the battery cell, and a vehicle. Background Technology

[0002] Generally, a secondary battery consists of a positive electrode, a negative electrode, and an electrolyte, which generate electrical energy through a chemical reaction. Besides portable devices, secondary batteries, due to their high applicability and convenient use, as well as their high energy density and other electrical properties, are widely used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric drive sources.

[0003] The primary advantage of such rechargeable batteries is their ability to significantly reduce the use of fossil fuels. Rechargeable batteries also have the advantage of producing no byproducts from energy use. Therefore, rechargeable batteries are attracting considerable attention as an environmentally friendly and energy-efficient new energy source.

[0004] Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell, or a single battery cell 100, is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells are sometimes connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, multiple battery cells 100 are sometimes connected in parallel to form a battery pack. Therefore, depending on the required output voltage and / or charge / discharge capacity, the number of battery cells and the electrical connection method in the aforementioned battery pack can be designed in various ways.

[0005] On the other hand, disclosed types of secondary battery cells include cylindrical battery cells, angular battery cells, and pouch battery cells. In a cylindrical battery cell, a separator membrane serving as an insulator is sandwiched between the positive and negative electrodes, and this membrane is rolled up to form a gel roll-shaped electrode assembly, which is then inserted into a battery can to form a battery. Furthermore, each of the aforementioned positive and negative electrodes may have a strip-shaped electrode tab connected to its uncoated portion. The electrode tab enables electrical connection between the electrode assembly and the exposed electrode terminals. For reference, the positive electrode terminal is the cover plate of a seal that seals the opening of the battery can, and the negative electrode terminal is the battery can itself. However, according to existing cylindrical battery cells with this structure, the current is concentrated in the strip-shaped electrode tab connected to the uncoated portion of the positive electrode and / or the uncoated portion of the negative electrode, resulting in high resistance, excessive heat generation, and poor current collection efficiency. That is, the cross-sectional area of ​​the electrode tab decreases rapidly, potentially causing a bottleneck phenomenon in current flow.

[0006] Resistance and heat generation are not major issues for small cylindrical battery cells with form factors of 18650 or 21700. However, when the form factor is increased to accommodate cylindrical battery cells in electric vehicles, more heat is generated around the electrode tabs during fast charging, potentially leading to fires in the cylindrical battery cells.

[0007] To address this issue, a cylindrical battery cell (a so-called tabless cylindrical battery cell) with the following structure has been disclosed: the uncoated positive electrode portion and the uncoated negative electrode portion are located at the upper and lower ends of the gel roll electrode assembly, respectively, and the current collector is welded to such uncoated portion, thereby improving the current collection efficiency.

[0008] The first electrode sheet and the second electrode sheet have a structure in which an active material is coated on a sheet-shaped current collector, and an uncoated portion is included on one long side along the winding direction.

[0009] The electrode assembly is manufactured by sequentially stacking a first electrode sheet and a second electrode sheet together with two separation membranes and then winding them in one direction. In this case, the uncoated portions of the first electrode sheet and the second electrode sheet are arranged in opposite directions.

[0010] After the winding process, the uncoated portions of the first electrode sheet and the second electrode sheet are bent toward the core. Then, current collectors are welded to the uncoated portions.

[0011] The uncoated positive and negative electrodes are not connected to any other electrode tabs. The current collector is connected to the external electrode terminals, and the current path along the winding axis of the electrode assembly forms a large cross-sectional area, thus having the advantage of reducing the resistance of the battery cell. This is because resistance is inversely proportional to the cross-sectional area of ​​the current flow path.

[0012] In tabless cylindrical battery cells, in order to improve the welding characteristics between the uncoated part and the current collector, it is necessary to apply strong pressure to the welding point of the uncoated part and bend the uncoated part as flat as possible.

[0013] However, when bending the welding point of the uncoated portion, its shape may become irregularly distorted and deformed. In this case, the deformed area may come into contact with the electrode plate of opposite polarity, potentially causing an internal short circuit or micro-cracks in the uncoated portion. Furthermore, the uncoated portion adjacent to the core of the electrode assembly may block all or a significant portion of the cavities formed in the core of the electrode assembly during bending. This causes problems in the electrolyte injection process. That is, the cavities in the core of the electrode assembly are used as channels for injecting electrolyte. However, if the corresponding channels are blocked, electrolyte injection becomes difficult. Moreover, during the insertion of the electrolyte injector into the cavity, interference occurs with the uncoated portion near the core, potentially causing the uncoated portion to tear.

[0014] Furthermore, the bent portions of the uncoated parts of the current collector need to be overlapped in multiple layers, with no gaps. Only in this way can sufficient weld strength be obtained, and even with the latest technologies such as laser welding, the problem of laser penetration into the electrode assembly, thereby damaging the separation membrane or active material, can be prevented.

[0015] Korean Patent Publication No. 2022-0023100 (published on March 2, 2022) discloses a cylindrical secondary battery with an improved current-collector structure. In this cylindrical secondary battery, the current collector plate is welded to the end of the uncoated portion via line contact. This results in a reduction in the welded cross-sectional area between the current collector plate and the uncoated portion due to gaps between the uncoated portion. Consequently, the resistance in the welded cross-sectional area, which serves as the current channel, increases, leading to increased heat generation in the battery cell and potentially increasing the risk of fire.

[0016] Korean Patent Publication No. 2016-0110610 (September 22, 2016) discloses a secondary battery and a cylindrical lithium secondary battery. The disclosed secondary battery has a configuration in which a first current collector is electrically connected to a first uncoated portion in direct contact, and a second current collector is electrically connected to a second uncoated portion in direct contact. In this structure, the first and second current collectors are still connected to the ends of the first and second uncoated portions respectively in line contact, thus the contact cross-sectional area between the current collectors and the uncoated portions is reduced due to gaps between the uncoated portions. Increasing the contact cross-sectional area is limited. Summary of the Invention

[0017] Technical problems to be solved

[0018] The present invention was made to solve the above-mentioned problems, and its purpose is to provide an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and vehicle including the present invention, which can expand the current path by increasing the welding cross-sectional area of ​​the electrode assembly and the current collector.

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

[0020] Furthermore, the present invention aims to provide an electrode assembly, a battery cell, a battery cell cutting device, and a battery pack and vehicle including the present invention, capable of preventing the boundary between the molded part and the cut surface from being torn or irregularly skewed.

[0021] Furthermore, the present invention aims to provide an electrode assembly structure capable of further increasing the volumetric specific capacitance of a battery cell, a method for manufacturing the same, and a processing apparatus for manufacturing the same.

[0022] Furthermore, the present invention aims to provide electrode assemblies, battery cells, battery cell cutting devices, and battery packs and vehicles including the present invention, which can reduce the heat generation of battery cells or significantly reduce the possibility of explosion.

[0023] The technical problem addressed by this invention is not limited to the objectives described above. Other objectives and advantages of this invention not mentioned will be understood through the following description, and will be further clearly understood through embodiments of this invention. Furthermore, it will be readily understood that the objectives and advantages of this invention can be achieved through the means and combinations thereof shown in the claims.

[0024] means of solving technical problems

[0025] To address the aforementioned problems, the present invention can be applied to an electrode assembly comprising a gel roll-shaped electrode unit body comprising a first electrode sheet and a second electrode sheet having different polarities stacked and wound together, and a separation membrane for achieving insulation between them.

[0026] The above-mentioned sheets can be stacked in the order of first electrode sheet, separation membrane, second electrode sheet, and separation membrane.

[0027] The winding process can be performed along the length of the stacked sheets. The axial length of the gel roll-shaped electrode unit body thus formed can correspond to the width of the stacked sheets.

[0028] At least one of the first and second electrode sheets has an uncoated portion without an active material layer at its width end. This uncoated portion is located at the axial end of the electrode unit body. The uncoated portion can be located on either side or both sides of the axial end of the electrode unit body.

[0029] The uncoated portion of the electrode unit body of the aforementioned electrode assembly has a pair of cut surfaces formed by cutting off a portion of the uncoated portion. The remaining uncoated portion after cutting off the portion constitutes the intended bending portion.

[0030] The aforementioned cut surfaces are formed by cutting along both sides of the uncoated portion in the diameter direction, with the core portion as the center. The aforementioned planned bending portion is positioned between a pair of cut surfaces.

[0031] The aforementioned electrode assembly includes a shaped portion formed by bending the aforementioned intended bending portion.

[0032] In essence, the inner end of the core portion of the cut surface can be formed as a straight line, and the outer end can be formed as an arc.

[0033] The central angle of the inner end of the core portion of the cut surface can be formed to be greater than or equal to 150° and less than 180°, and the outer end is formed to be arc-shaped.

[0034] The aforementioned cut surface can be formed by cutting a portion that separates the uncoated portion and the coated portion by a certain distance in the axial direction. In other words, the cut surface can be considered as cutting off the uncoated portion of the coated portion and the uncoated portion.

[0035] The aforementioned molding portion can be formed along the diametrical direction of the aforementioned core portion.

[0036] The aforementioned molding part can be a straight, extending shape.

[0037] In the edge direction of the electrode assembly, the width of the above-mentioned molded portion can be formed to be substantially the same.

[0038] In the edge direction of the electrode assembly, the above-mentioned molding portion can be formed such that the width of the core portion side is different from the width of the periphery.

[0039] The aforementioned forming portion can be shaped such that the intended bending portion is laid flat along the radial direction of the electrode unit main body. The intended bending portion can be laid flat towards the core portion.

[0040] Because the aforementioned molding section is folded down, the axial length of the electrode unit body can be further compacted. In other words, it is possible to further ensure the axial length of the coated portion of the electrode unit body, which is housed within a battery can of the same size. Therefore, the volumetric capacitance of the battery unit can be further ensured.

[0041] The core portion is formed into a hollow shape that extends through the center of the main body portion of the electrode unit.

[0042] The main body of the aforementioned electrode unit is formed in a cylindrical shape.

[0043] To prevent the core portion from being blocked by the bent portion when the assembly is laid down facing the core portion, the uncoated portion located near the core portion in both the core portion and the outer periphery of the electrode assembly can be removed. This removal of the uncoated portion can be performed before the winding process.

[0044] That is, in the winding direction, within a specified interval adjacent to the core portion, the uncoated portion may be a shape that has been removed.

[0045] If a sheet-like stack with the uncoated portion on the core side removed is wound up, the uncoated portion near the core has already been removed before the aforementioned cut surface is formed. That is, the aforementioned planned bending portion is not provided to the core side. Therefore, even if the planned bending portion is bent towards the core side, the laid-down molding portion will not obstruct the core portion of the electrode assembly.

[0046] The aforementioned electrode assembly may further include: a recessed portion disposed on the core portion side of the uncoated portion of the electrode unit body portion, and having a height that is recessed in the axial direction compared to the uncoated portion disposed on the outer side in the radial direction relative to the recessed portion.

[0047] The electrode assembly may further include: a plurality of cutting lines, which are provided on the outer side of the uncoated portion of the electrode unit body relative to the recessed portion in the radial direction, and formed to a predetermined depth in the axial direction.

[0048] The radial width of the recess can correspond to the axial height of the expected bend, measured from the lower end of the cutting line that is arranged adjacent to the recess in the radial direction.

[0049] The cutting depth of the aforementioned cutting line can reach a specified portion that is separated from the boundary between the uncoated portion and the coated portion by a certain distance in the axial direction.

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

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

[0052] The battery unit includes: a battery can housing the electrode assembly and electrically connected to either the first electrode plate or the second electrode plate, having a first polarity; a sealing cap sealing the open end of the battery can; and a first current collector electrically connected to the other of the first electrode plate and the second electrode plate, having a second polarity.

[0053] The first current collector can be fixed and electrically connected to the forming part of the electrode assembly by means of welding or other methods.

[0054] Either the first electrode plate or the second electrode plate can be directly connected to the battery canister or connected through the second current collector.

[0055] The battery can may include a support portion that further protrudes radially inward from the inner circumference of the battery can. This support portion can support the sealing cap portion.

[0056] The aforementioned battery cell may also include an insulator for preventing short circuits between cells of different polarities.

[0057] The insulator can be sandwiched between the battery can and the sealing cover to achieve insulation between them. More specifically, the insulator is sandwiched between the outer peripheral surface of the sealing cover and the inner peripheral surface of the battery can, and can be sandwiched between the support portion and the sealing cover.

[0058] The insulator can be sandwiched between the battery tank and the first current collector to achieve insulation between them. For example, the insulator can be sandwiched between the first current collector and the support portion.

[0059] The present invention provides a battery pack comprising at least one of the above-described battery cells.

[0060] The present invention provides a vehicle comprising at least one of the above-described battery packs.

[0061] The present invention provides a cutting device for cutting the uncoated portion of the axial end of the electrode unit body of the above-mentioned electrode assembly.

[0062] The cutting device includes: a first cutting section that moves along the axial direction of the electrode assembly to form a first cutting line along the axial direction of the uncoated portion; and a second cutting section that moves along the radial direction of the electrode assembly to form a second cutting line along the circumferential direction of the uncoated portion.

[0063] The second cutting section forms a second cutting line that cuts a portion of the uncoated portion that is wound in the circumferential direction along the circumferential direction, and forms a cutting line in such a way that the second cutting line is connected to the first cutting line.

[0064] By connecting the first cutting line and the second cutting line, the uncoated portion surrounded by the first cutting line and the second cutting line can be cut.

[0065] The present invention can provide a processing apparatus comprising: the above-mentioned cutting device; and a stamping unit for bending the remaining portion to be bent after being cut by the cutting device.

[0066] The aforementioned stamping section forms a molded section by applying pressure to bend the uncoated section into the desired bending section.

[0067] The aforementioned expected bending portion is pressurized in the radial direction by the aforementioned stamping portion, thereby bending the portion of the expected bending portion corresponding to the aforementioned second cutting line and allowing it to be laid down in the radial direction.

[0068] The aforementioned first cutting section may include a pair of first blades arranged side by side with the aforementioned first cutting section.

[0069] The aforementioned first cutting edge can extend along the axial direction and form a cutting edge at the front end in the axial direction.

[0070] The first cutting section may further include a first vibration generating section. The first vibration generating section can generate micro-vibrations.

[0071] The second cutting portion can be formed into a quadrilateral shape to cut a portion of the uncoated portion into a semi-circle. The front end of the second cutting portion can be formed into a straight line. The front end of the second cutting portion can be formed with a blade.

[0072] Furthermore, the front end of the second cutting section can be formed into a shape that is inclined with respect to the center. Blades can be formed on both sides of the top end of the second cutting section.

[0073] The interior angle of the aforementioned front end can be an obtuse angle less than 180 degrees.

[0074] The interior angle of the aforementioned front end can be greater than 150 degrees.

[0075] The second cutting section may further include a second vibration generating section. The second vibration generating section can generate micro-vibrations.

[0076] The aforementioned stamping portion can move along the radial direction (radial direction) of the aforementioned electrode unit main body portion, causing the expected bending portion of the aforementioned uncoated portion to bend towards the core portion of the aforementioned electrode unit main body portion.

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

[0078] The manufacturing method of such a battery cell includes the steps of stacking a first electrode sheet, a second electrode sheet, and a separation film, and then winding them up to manufacture an electrode assembly.

[0079] Therefore, the electrode assembly described above may include an electrode unit body portion that together winds up the plurality of electrode sheets and the plurality of separation membranes.

[0080] The main body of the aforementioned electrode unit can be cylindrical.

[0081] The main body of the aforementioned electrode unit may have a hollow core.

[0082] At least one of the first and second electrode sheets mentioned above includes an uncoated portion without an active material layer at either end in the width direction. When both the first and second electrode sheets have uncoated portions, these uncoated portions can be respectively provided at both ends in the width direction.

[0083] Therefore, it can be provided in the form of an uncoated portion extending and protruding along the axial direction at the axial end of the main body of the electrode unit.

[0084] In the above-mentioned winding direction, within a specified interval adjacent to the above-mentioned core portion, the above-mentioned uncoated portion may be a shape that is deleted.

[0085] The removal of the uncoated portion described above can be performed after the electrode laminate is formed but before the winding process. Such a process can be performed, for example, by laser processing.

[0086] The removal of the uncoated portion mentioned above can be performed before the step of providing the electrode sheet is completed, which is before the electrode stack is formed.

[0087] The removal of the uncoated portion can be performed after the electrode laminate is wound to form the main body of the electrode unit. Such machining can be performed, for example, by a cutting tool equipped with an ultrasonically vibrating blade.

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

[0089] Specifically, the above-mentioned uncoated portion removal step includes: the first cutting portion moves along the axial direction of the battery cell to cut the uncoated portion to a predetermined depth along the axial direction, thereby forming a first cutting line in the uncoated portion along the axial direction.

[0090] The aforementioned first cutting lines can form a pair. A pair of the aforementioned first cutting lines can be arranged side by side along the diametrical direction.

[0091] Furthermore, the above-mentioned uncoated portion removal step includes: after forming the first cutting line, the second cutting portion moves from the outer periphery of the battery cell toward the radial direction to form a second cutting line in the uncoated portion along the circumferential direction.

[0092] The aforementioned second cutting lines can form a pair. The aforementioned second cutting lines extend in the circumferential direction, and the pair of aforementioned second cutting lines are neatly arranged in the radial direction.

[0093] The length of the edge direction of the pair of the above-mentioned second cutting lines can gradually increase from the core side to the outer periphery along the radial direction.

[0094] The second cutting section cuts the uncoated portion in such a way that the second cutting line connects to two first cutting lines adjacent to each other in the edge direction. As a result, the uncoated portion surrounded by the second cutting line formed in the circumferential direction and a pair of first cutting lines respectively connected to the two ends of the second cutting line can be cut.

[0095] The cut surface formed at the location where the uncoated portion is cut can be formed in a semi-circular shape on both sides of the core portion.

[0096] The inner end of the core portion of the cut surface can be formed as a straight line, and the outer end can be formed as an arc.

[0097] The central angle of the inner end of the core portion of the cut surface can be greater than or equal to 150° and less than 180°, and the outer end is formed into an arc shape.

[0098] The manufacturing method of the battery cell may further include: a forming part step, bending along the radial direction and laying down the uncoated part remaining after being cut by multiple cutting lines, i.e. the expected bending part.

[0099] The bending process described above can be performed by pressing the expected bending portion along the radial direction using a stamping section.

[0100] The aforementioned molding portion can be formed side-by-side with the aforementioned electrode unit main body portion in the diametrical direction.

[0101] The above-mentioned molding part can be formed into a shape in which the expected bending part of the above-mentioned uncoated part is laid down towards the core part of the above-mentioned electrode unit body part.

[0102] The aforementioned cut surface can be formed by cutting a portion that separates the uncoated portion and the coated portion by a certain distance in the axial direction.

[0103] The first cutting section can be vibrated by the first vibration generating section to cut the uncoated section. The first cutting section can be an ultrasonic cutter.

[0104] The second cutting section can cut the uncoated portion by vibrating the second vibration generating section. The second cutting section can be an ultrasonic cutter.

[0105] Invention Effects

[0106] According to the present invention, the forming part is welded in a state of contact with the current collector surface, so as the area of ​​the forming part increases, the current path between the electrode assembly and the current collector can be relatively increased.

[0107] According to the present invention, the molding portion increases the current path corresponding to the area between the uncoated portions, so even when applied to large-capacity battery cells, it can suppress the increase in heat generation of the battery cells and reduce the possibility of fire.

[0108] According to the present invention, after the expected cutting portion and the expected bending portion are separated from each other in the uncoated portion, the expected cutting portion is cut to form a cutting surface, and the expected bending portion is bent under pressure to form a forming portion. Therefore, when the expected bending portion is bent under pressure to form the forming portion, it is possible to prevent the boundary between the forming portion and the cutting surface from being torn or irregularly deformed.

[0109] According to the present invention, it is possible to prevent the boundary between the molding part and the cutting part from being torn or deformed, thus preventing contact with the electrode sheet of the opposite polarity in the torn or deformed part.

[0110] According to the present invention, the boundary between the uncoated portion and the coated portion is prevented from being torn or deformed, thus preventing the active material coated on the coated portion from detaching from the coated portion or weakening its adhesion. Therefore, it is possible to suppress the reduction in the performance and capacity of the battery cell.

[0111] According to the present invention, the edges of the separation membrane can be prevented from lifting or being damaged due to tearing or deformation at the boundary. This prevents short circuits between the first and second electrode plates. Furthermore, it reduces heat generation in the battery cell or significantly lowers the possibility of explosion.

[0112] According to the present invention, the cut surface is formed by cutting the uncoated portion extending along the axial direction in the region that does not constitute the molded portion, thus shortening the length occupied by the uncoated portion in the axial direction at both ends of the electrode unit body. This further ensures the axial volume of the electrode unit body housed in the battery can. Therefore, the volumetric capacitance of the battery unit can be improved.

[0113] The above-mentioned effects and specific effects of the invention will be explained while describing the specific matters for carrying out the invention below. Attached Figure Description

[0114] Figure 1 This is a top view that briefly illustrates the electrode unit stack according to the present invention.

[0115] Figure 2 It briefly shows the cut along the AA direction. Figure 1 A cross-sectional view of the state of the electrode unit stack.

[0116] Figure 3 This is a brief illustration of winding. Figure 1 A three-dimensional view of the electrode unit body in the state of the electrode unit stack manufacturing process.

[0117] Figure 4 This is a perspective view that briefly shows the state of the main body of the electrode unit being cut according to a first embodiment of the first cutting part of the present invention.

[0118] Figure 5 This is a top view showing a first embodiment of the first cutting section according to the present invention.

[0119] Figure 6 This is a top view that briefly shows the state of the electrode unit body portion being cut by the first cutting section according to the present invention.

[0120] Figure 7 This is a top view showing a second embodiment of the first cutting section according to the present invention.

[0121] Figure 8 This is a top view that briefly shows the state of the main body of the electrode unit being cut according to a second embodiment of the first cutting part of the present invention.

[0122] Figure 9 This is a perspective view showing the state of the electrode unit body portion before the second cutting section of the present invention cuts the uncoated portion.

[0123] Figure 10 This is a side view showing the state of the uncoated portion of the electrode unit body portion cut by the second cutting section according to the present invention.

[0124] Figure 11 This is a perspective view showing the state of the stamping section under pressure and expected bending section in the state of the uncoated portion of the electrode unit body portion cut by the second cutting section according to the present invention.

[0125] Figure 12 This is a perspective view showing the state in which the stamping part is pressurized and the bending part is expected to form a forming part according to the present invention.

[0126] Figure 13 This is a side view showing the state in which the stamping part is pressurized and the bending part is expected to form a forming part according to the present invention.

[0127] Figure 14 This is a flowchart illustrating a method for manufacturing a battery cell according to the present invention.

[0128] Figure 15 This is a cross-sectional view showing the electrode assembly according to the present invention.

[0129] Figure 16 This is a perspective view showing the state in which the electrode assembly according to the present invention is housed in the battery pack casing.

[0130] Figure 17 This is a perspective view showing the battery pack according to the present invention installed in a vehicle.

[0131] Marker description

[0132] 10: Electrode laminate

[0133] 11: First electrode plate

[0134] 12: Second electrode plate

[0135] 13: Separation membrane

[0136] 14: Coated section

[0137] 15: Uncoated section

[0138] 16: Boundary section

[0139] 16a: Second cutting line

[0140] 100: Battery cell

[0141] 101: Battery pack casing

[0142] 110: Electrode assembly

[0143] 111: Electrode unit main body

[0144] 112: Core Section

[0145] 112a: Recessed portion

[0146] 113: First cutting line

[0147] 115: Facial Cutting

[0148] 115a: Expected cutting section

[0149] 117: Molding Section

[0150] 117a: Expected bending section

[0151] 120: Battery can

[0152] 121: Battery tank main body

[0153] 122: Support section

[0154] 123: Clamping part

[0155] 130: First collector board

[0156] 132: Central hole

[0157] 140: Second collector board

[0158] 150: Sealing cap

[0159] 151: Cover plate

[0160] 152: External terminal

[0161] 153: Exhaust plate

[0162] 155: Guidance Department

[0163] 157: Insulator

[0164] 210: First Cutting Department

[0165] 211: The First Blade

[0166] 213: First vibration generating part

[0167] 215: First connecting hole portion

[0168] 220: Second Cutting Department

[0169] 221: The Second Blade

[0170] 223: Second vibration generating part

[0171] 230: Stamping section

[0172] 300: Vehicles Detailed Implementation

[0173] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0174] This invention is not limited to the embodiments disclosed below, and can be modified in various ways and implemented in different ways. It should be noted that these embodiments are provided merely to fully disclose the invention and to inform those skilled in the art of its scope of protection. Therefore, this invention is not limited to the embodiments disclosed below, and should be interpreted as including, in addition to replacing or adding to the configuration of one embodiment or another, all modifications, equivalents, and substitutions encompassing the technical concept and scope of this invention.

[0175] The accompanying drawings are merely illustrative of the embodiments disclosed in this specification. The technical concepts disclosed in this specification are not limited to the drawings and should be understood to include all modifications, equivalents, and substitutions encompassing the ideas and technical scope of this invention. In the drawings, constituent elements are sometimes shown too large or too small for the purpose of aiding understanding, but this should not be construed as limiting the scope of protection of this invention to these figures.

[0176] The terminology used in this specification is for illustrative purposes only and is not intended to limit the invention. Furthermore, singular expressions include plural expressions unless the context clearly indicates a different meaning. In this specification, terms such as "~" including or constituting of "~" are used to specify the presence of the features, numbers, steps, actions, constituent elements, components, or combinations thereof described in the specification. That is, terms such as "~" including or constituting of "~" should not be construed as excluding the possibility of the presence or addition of one or more other features, numbers, steps, actions, constituent elements, components, or combinations thereof.

[0177] Terms such as "first," "second," etc., which include ordinal numbers, can be used to describe various constituent elements, but multiple constituent elements are not limited to multiple terms. Multiple terms are used only to distinguish one constituent element from other constituent elements.

[0178] When a constituent element is described as being "connected" or "joined" with other constituent elements, it can be directly connected or joined to the other constituent elements, but it should also be understood that other constituent elements may exist in between. Conversely, when a constituent element is described as being "directly connected" or "directly joined" with other constituent elements, it should be understood that no other constituent elements exist in between.

[0179] When a constituent element is described as being located "above" or "below" other constituent elements, it should be understood that, in addition to being positioned directly above the other constituent elements, other constituent elements may exist in between.

[0180] 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 that are commonly used and defined in dictionaries should be interpreted as having the same meaning as they have in the context of the relevant art, and should not be interpreted as having an idealized or overly formalized meaning unless explicitly defined in this application.

[0181] The electrode assembly according to an embodiment of the present invention will now be described.

[0182] For ease of explanation, in this specification, the direction along the length of the winding axis of the electrode assembly 110 wound in a gel roll shape is referred to as the axial direction Y. Furthermore, the direction surrounding the winding axis is referred to as the circumferential direction X or the edge direction. Additionally, the direction closer to or farther from the winding axis is referred to as the radial direction or the radial direction Z. In particular, the direction closer to the winding axis is referred to as the centripetal direction, and the direction farther from the winding axis is referred to as the centrifugal direction.

[0183] Figure 1This is a simplified top view illustrating the electrode unit stack according to the present invention. Figure 2 This shows a cut along the AA direction. Figure 1 A cross-sectional view of the state of the electrode unit stack. Figure 3 This shows the roll-up. Figure 1 A three-dimensional view of the electrode unit body in the state of the electrode unit stack manufacturing process.

[0184] Reference Figures 1 to 3 According to an embodiment of the present invention, the electrode laminate 10 includes a first electrode sheet 11, a second electrode sheet 12, and a separation membrane 13. The electrode laminate 10 is constructed by laminating the separation membrane 13 between the sheet-like first electrode sheet 11 and the second electrode sheet 12. For example, the electrode laminate 10 may be constructed by laminating one first electrode sheet 11, one second electrode sheet 12, and two separation membranes 13. Furthermore, the electrode laminate 10 may also be constructed by laminating two or more first electrode sheets 11, two or more second electrode sheets 12, and three or more separation membranes 13. In such an electrode laminate 10, as the number of laminated first electrode sheets 11, second electrode sheets 12, and separation membranes 13 increases, the winding time and manufacturing time of the electrode assembly 110 with the desired diameter can be shortened.

[0185] The first electrode sheet 11 and the second electrode sheet 12 each include a coated portion 14 with an active material coating and an uncoated portion 15 without an active material coating. The uncoated portion 15 may be formed on one side in the width direction of the first electrode sheet 11 and the second electrode sheet 12. At least a portion of the uncoated portion 15 can 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 positioned on one side in the axial direction. Figure 1 The uncoated portion 15 of the second electrode sheet 12 can be disposed on the other side in the axial direction (either on the upper or lower side).

[0186] The uncoated portion 15 of the first electrode sheet 11 and the uncoated portion 15 of the second electrode sheet 12 can be formed to have the same width. Alternatively, the uncoated portion 15 of the first electrode sheet 11 and the uncoated portion 15 of the second electrode sheet 12 can be formed to have different widths.

[0187] The first electrode 11 can be a negative electrode coated with a negative active material, and the second electrode 12 can be a positive electrode coated with a positive active material. The first electrode 11 can be a positive electrode coated with a positive active material, and the second electrode 12 can be a negative electrode coated with a negative active material.

[0188] The first electrode 11 and the second electrode 12 include a current collector (not shown) made of metal foil and an active material layer (not shown). The metal foil can be aluminum or copper. The active material layer can be coated on one or both sides of the first electrode 11 and the second electrode 12.

[0189] The width of the uncoated portion 15 is significantly narrower than the width of the coated portion 14. The uncoated portion 15 can be formed as a narrow strip. Furthermore, the uncoated portion 15 can also be composed of multiple serrated segments that are separated along the length direction of the uncoated portion 15. The shape of the serrated segments can be varied into quadrilaterals, triangles, semicircles, semi-ellipses, parallelograms, etc.

[0190] The uncoated portion 15 described above may be a shape in which a portion of the region C near the core side is removed. The corresponding region may be removed by laser processing or the like after forming the electrode laminate 10 and before winding.

[0191] Of course, it can also be a shape in which the uncoated portion of the corresponding interval C is pre-deleted during the electrode sheet providing step, or it can be formed by post-processing after winding to create the uncoated portion removal area on the core side.

[0192] In this invention, the positive electrode active material coated on the first electrode sheet 11 and the negative electrode active material coated on the second electrode sheet 12 can be active materials known in the art, without any limitation.

[0193] The aforementioned positive electrode active material can be mainly composed of lithium intercalation material, such as layered compounds like lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2), or compounds substituted with one or more transition metals; chemical formula Li 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2 (LiMnO2); lithium copper oxides (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and LiNi 1-x M x Lithiated nickel oxide expressed as O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, x = 0.01 to 0.3); chemical formula LiMn 2-x M xLithium-manganese composite oxides expressed as O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which a portion of the lithium in the chemical formula is replaced by an alkaline earth metal ion; disulfide compounds; composite oxides formed from Fe2(MoO4)3 or combinations thereof, etc. The types described above can be used as positive electrode active materials, but are not limited to these.

[0194] The aforementioned positive electrode current collector has a thickness of, for example, 3 to 500 μm. As such a positive electrode current collector, any material that does not cause chemical changes in the battery and is conductive can be used without any restrictions. For example, the positive electrode current collector can be made of stainless steel, aluminum, nickel, titanium, carbon electrodes, or materials whose surfaces are treated with carbon, nickel, titanium, silver, etc., on the surface of aluminum or stainless steel. The electrode current collector can also have fine irregularities formed on its surface to improve the adhesion of the positive electrode active material. Such an electrode current collector can be formed in various ways, such as thin films, sheets, foils, meshes, porous bodies, foams, and nonwoven fabrics.

[0195] Conductive materials can also be mixed into the aforementioned positive electrode active material particles. For example, based on the total weight of the mixture containing the positive electrode active material, such conductive material can be added at 1 to 50% by weight. As such conductive material, any material that does not cause chemical changes in the battery and has high conductivity can be used without any restrictions. For example, conductive materials can include natural graphite, artificial graphite, etc.; carbon black, acetylene black, Ketjen black, channel black, furnace black, lampblack, summer black, etc.; conductive fibers such as carbon fiber and metal fiber; metal powders such as fluorocarbon, aluminum, and nickel powder; conductive oxides such as zinc oxide and potassium titanate; conductive oxides such as titanium oxide; and conductive raw materials such as polystyrene derivatives.

[0196] Furthermore, the negative electrode sheet is manufactured by coating negative electrode active material particles onto the negative electrode current collector and then drying them. Depending on the requirements, it may also include the conductive materials, adhesives, solvents, and other components described above.

[0197] The aforementioned negative electrode current collector has a thickness of, for example, 3 to 500 μm. As such a negative electrode current collector, any material that does not cause chemical changes in the corresponding battery and is conductive can be used without any limitations. For example, the negative electrode current collector can be made of copper, stainless steel, aluminum, nickel, titanium, carbon electrodes, materials with surface treatments of copper or stainless steel using carbon, nickel, titanium, silver, etc., aluminum-cadmium alloys, etc. Furthermore, similar to the positive electrode current collector, fine irregularities can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as thin films, sheets, foils, meshes, porous bodies, foams, and nonwoven fabrics.

[0198] The above-mentioned negative electrode active material can use, for example, carbon such as hard carbon and graphite-based carbon; Li x Fe2O3 (0 ≤ x ≤ 1), Li x WO2 (0 ≤ x ≤ 1), Sn x Me 1-x Me' y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1, Group 2, Group 3 elements in the periodic table, halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8) metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; 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.

[0199] The adhesive polymer that can be used in the electrode sheets 11 and 12 is a component that assists in the bonding of the electrode active material particles to conductive materials and the bonding to the electrode current collector. For example, it is added at a rate of 1 to 50% by weight based on the total weight of the mixture containing the electrode active material. Examples of such adhesive polymers include those selected from polyvinylidene fluoride-co-hexafluoropropylene (PVdF), polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polybutyl acrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. The adhesive polymer is any one of the following groups: acetatepropionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethyl cellulose, cyanoethylsucrose, pullulan, and carboxyl methyl cellulose, or a mixture of two or more of them, but is not limited to these.

[0200] Non-limiting examples of solvents used to manufacture the above-mentioned electrodes include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water, or mixtures thereof. Such solvents provide an appropriate level of viscosity to form a paste coating on the electrode current collector surface to the desired degree.

[0201] The separation membrane 13 has a porous polymer substrate and a porous coating on both sides of the porous polymer substrate, which includes inorganic particles and adhesive polymers.

[0202] The aforementioned porous polymer substrate can be a polyolefin-based porous substrate.

[0203] The aforementioned porous polyolefin substrate can be in the form of a film or a non-woven web. This porous structure facilitates the smooth movement of electrolyte between the positive and negative electrodes. The porous structure also increases the substrate's electrolyte impregnation, ensuring excellent ionic conductivity, preventing an increase in internal resistance of the electrochemical element, and thus preventing performance degradation.

[0204] As the polyolefin porous substrate used in this invention, any planar phase porous substrate commonly used in electrochemical elements can be used, and various materials or forms can be selected according to the purpose.

[0205] The polyolefin porous substrate may be a film or non-woven web formed of high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, polypropylene, or a mixture of two or more thereof, but is not limited to these.

[0206] The aforementioned polyolefin porous substrate can have a thickness of 8 to 30 μm; however, this is just an example, and thicknesses exceeding the above range can be used in consideration of mechanical properties or the efficient charge-discharge characteristics of the battery.

[0207] The separation membrane 13 according to the present invention can have a thickness of 1 to 100 μm or 5 to 50 μm. If the thickness of the separation membrane 13 is less than 1 μm, the function of the separation membrane 13 cannot be fully utilized, and the mechanical properties may deteriorate. If the thickness of the separation membrane 13 exceeds 100 μm, the battery characteristics may deteriorate during high-efficiency charge and discharge. Furthermore, it can have a porosity of 40 to 60% and an venting rate of 150 to 300 seconds / 100 mL.

[0208] When using the separation membrane 13 according to a specific embodiment of the present invention, porous coatings are provided on both sides of the porous polymer substrate, so a uniform solid electrolyte interface layer can be formed by improving the impregnation performance with electrolyte. Compared with the conventional single-sided inorganic coating separation membrane 13, superior venting performance can be ensured. For example, it can be within 120s / 100cc. Furthermore, even with inorganic porous coatings on both sides, a thickness comparable to that of the conventional single-sided inorganic coating separation membrane 13 can be achieved. For example, it can be within ~15.0μm.

[0209] Furthermore, when using the separator 13 according to a specific embodiment of the present invention, the stability of the separator 13 is improved, thereby ensuring heat resistance and compression resistance. Specifically, it can ensure heat resistance with a thermal shrinkage rate of less than 5% at a 180°C reference, and can ensure a punch strength of 550 gf or more. When core deformation occurs during battery cycling using such a separator 13, damage or penetration of the separator 13 can be prevented at the step.

[0210] The electrode assembly 110 manufactured using the electrode laminate 10 described above will be explained.

[0211] Figure 4 This is a perspective view that briefly shows the state of the main body of the electrode unit being cut according to a first embodiment of the first cutting part of the present invention. Figure 5 This is a top view showing a first embodiment of the first cutting section according to the present invention. Figure 6 This is a top view that briefly shows the state of the electrode unit body portion being cut by the first cutting section according to the present invention. Figure 7 This is a top view showing a second embodiment of the first cutting part according to the present invention. Figure 8 This is a top view that briefly shows the state of the main body of the electrode unit being cut according to the second embodiment of the first cutting part of the present invention. Figure 9 This is a perspective view showing the state of the electrode unit body before the second cutting section of the present invention cuts the uncoated portion. Figure 10 This is a side view showing the state of the uncoated portion of the electrode unit body portion cut by the second cutting section according to the present invention. Figure 11This is a perspective view showing the state in which the electrode unit body is cut by the second cutting section according to the present invention, and the expected bending section is formed by the stamping section. Figure 12 This is a perspective view showing the state in which the stamping part is pressurized and bent to form the molded part according to the present invention. Figure 13 This is a side view showing the state in which the stamping part is pressurized and bent to form the molded part according to the present invention.

[0212] Reference Figures 4 to 13 The electrode assembly 110 includes an electrode unit main body 111, multiple cut surfaces 115, and multiple molding surfaces 117.

[0213] The electrode unit body 111 is a cylindrical portion formed by gel roll winding in a state where a separation membrane 13 is stacked between sheet-like first electrode sheets 11 and second electrode sheets 12. As described above, uncoated portions 15 without active material layers are formed at the width-direction ends of the first electrode sheets 11 and second electrode sheets 12. These uncoated portions are respectively disposed on one side and the other side of the electrode unit body 111 in the axial direction and extend along the axial direction.

[0214] The electrode unit main body 111 is formed by winding the aforementioned electrode laminate 10, which extends along its length, around the edge of a take-up bar (not shown) and then pulling the take-up bar out of the electrode unit main body 111. In this case, the more first electrode sheets 11, second electrode sheets 12, and separation membrane 13 are stacked in the electrode laminate 10, the shorter the take-up time and manufacturing time of the electrode assembly 110 can be. A hollow core portion 112 is formed at the location in the electrode unit main body 111 where the take-up bar is pulled out.

[0215] On one side of the electrode unit main body 111 in the axial direction, the uncoated portion 15 of the first electrode sheet 11 is exposed at a certain height, and on the other side of the electrode unit main body 111 in the axial direction, the uncoated portion 15 of the second electrode sheet 12 is exposed at a certain height.

[0216] Furthermore, through the uncoated portion deletion portion described above, a recess 112a is formed in the uncoated portion interval adjacent to the core portion 112.

[0217] The first cutting section 210 cuts the uncoated portion 15 of the electrode unit main body 111 along the axial direction, separating the planned cutting section 115a and the planned bending section 117a along the circumferential direction. A first cutting line 113 is formed between the planned cutting section 115a and the planned bending section 117a. The first cutting line 113 is formed in a shape (vertical shape) extending from the axial end of the uncoated portion 15 toward the electrode unit main body 111 along the axial direction. At this time, the planned cutting section 115a and the planned bending section 117a remain upright along the axial direction of the electrode unit main body 111.

[0218] The second cutting portion 220 cuts the lower portion of the expected cut portion 115a of the uncoated portion 15 in the axial direction along the radial direction, thereby removing the expected cut portion 115a from the electrode unit body portion 111. The second cutting portion 220 forms a second cutting line 16a extending in the circumferential direction at the lower portion of the uncoated portion 15 located in the region corresponding to the expected cut portion 115a. The second cutting line 16a is formed along the edge direction of the uncoated portion 15 and is formed at the lower portions of a plurality of uncoated portion portions arranged adjacent to each other in the radial direction. Once the two ends of the second cutting line 16a in the circumferential direction connect with the first cutting lines 113 located on both sides of the expected cut portion 115a in the circumferential direction, the expected cut portion 115a, surrounded by the pair of first cutting lines 113 and second cutting lines 16a, detaches from the electrode unit body portion 111. The shorter uncoated portion remaining after cutting the expected cut portion 115a constitutes the cut surface portion 115.

[0219] Thus, a cut surface 115 and a planned bending portion 117a are formed in the uncoated portion 15 of the electrode unit body portion 111.

[0220] To prevent buckling that may occur when cutting the thin uncoated portion 15 along the axial direction, an ultrasonic cutter can be used to cut the first cutting portion 210 of the first cutting line 113.

[0221] The first cutting section 210 includes a pair of first blades 211 arranged side by side on both sides of a position corresponding to the diameter portion of the electrode unit main body 111, and a pair of first vibration generating sections 213 for fixing the first blades 211 respectively. Each of the first vibration generating sections 213 is fixed with one first blade 211.

[0222] The first vibration generating part 213 mentioned above includes a plate and a vibration source for driving the plate. The plate may be formed in the shape of a quadrilateral.

[0223] The base end of the first blade 211 can be fixed to the surface of the plate of the first vibration generating part 213. The first blade 211 extends in a direction corresponding to the axial direction of the electrode unit main body 111, and has a sharp blade at the front end.

[0224] The aforementioned pair of first blades 211 are symmetrically arranged on the corresponding first vibration generating part 213 with reference to the diameter portion of the electrode unit main body 111. An embodiment of this feature will be described below.

[0225] Reference Figures 4 to 6 Using the diameter of the electrode unit main body 111 as a reference, a pair of first cutting edges 211 for defining the expected bending portion 117a can be arranged linearly on both sides of the diameter. In this case, the pair of first cutting edges 211 are arranged at the same distance from the diameter of the electrode unit main body 111. Therefore, when the pair of first cutting edges 211 cut the uncoated portion 15 of the electrode unit main body 111, a linear first cutting line 113 can be formed on both sides of the diameter of the uncoated portion 15.

[0226] The above embodiment shows a structure in which a pair of first blades 211 are arranged parallel to each other to define the expected bend 117a. 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 in a shape where the distance between them gradually increases as they move toward the centrifugal side or as they move toward the centripetal side. Furthermore, an example of the first blades 211 being straight is shown, but this does not mean that the first blades 211 must be straight. For example, the first blades 211 may also be in a gently curved shape.

[0227] Furthermore, the above embodiment shows a structure in which a pair of first cutting edges 211 for defining the expected bending portion 117a are respectively fixed to a pair of first vibration generating portions 213. However, the pair of first cutting edges 211 can also be fixed together to a single first vibration generating portion 213.

[0228] Furthermore, the above embodiment illustrates a method for cutting the uncoated portion using a pair of first blades 211 to define the expected bending portion 117a. However, this does not preclude the possibility that one of the first blades 211 first processes either side of the diameter portion of the electrode unit body 111 before processing the remaining side.

[0229] Furthermore, in the above embodiment, the first blade 211 is shown to be a blade shape that extends straight and continuously. However, the blade may be discontinuous in the section where the uncoated portion is not cut (for example, the core portion section).

[0230] Reference Figure 7 as well as Figure 8The aforementioned pair of first blades 211 are arranged at a certain angle with respect to the diameter of the electrode unit main body 111. In this case, the outer tilt angle θ2 of the first blades 211 can be greater than or equal to 150° and less than 180°. Therefore, if the pair of first blades 211 cuts the uncoated portion 15 of the electrode unit main body 111, a first cutting line 113 with an inclined shape can be formed on both sides of the diameter of the uncoated portion 15.

[0231] Of course, the outer tilt angle θ2 of the first blade 211 can be greater than 180° and less than or equal to 210°. The angle of such a pair of first blades 211 can be appropriately selected according to the diameter of the electrode unit body 111 or the capacitance of the battery pack and the shape of the current collectors 130 and 140 welded thereon.

[0232] The above embodiment shows a structure in which a pair of first blades 211, for defining the expected bending portion 117a, are symmetrically inclined relative to each other with respect to the center of the core portion 112. However, it is not necessary to form a structure in which the pair of first blades 211 are symmetrically inclined with respect to the center of the core portion 112. For example, the pair of first blades 211 can be formed at different angles as they move from the center of the core portion 112 toward the centripetal side. Furthermore, an example of the first blades 211 being straight is shown, but this does not mean that the first blades 211 must be straight. For example, the first blades 211 can also be in a shape that bends slowly toward the core portion 112 or its opposite side.

[0233] The first vibration generating unit 213 may include an ultrasonic transducer. The first vibration generating unit 213 performs ultrasonic vibration when the first blade 211 moves in the axial direction toward the electrode unit main body 111 to cut the uncoated portion 15.

[0234] If the force of the first blade 211 pressing the uncoated portion 15 in the axial direction is not used for processing the first cutting line 113 but instead presses the uncoated portion 15, the uncoated portion 15 may be bent or deformed, such as bending or folding, in the uncoated portion 15 near the first cutting line 113.

[0235] When the first blade 211 is subjected to ultrasonic vibration, the phenomenon described above is prevented when the first blade 211 cuts the uncoated portion 15, and the cutting process is performed very smoothly. As a result, the cutting speed of the uncoated portion 15 is increased, and a smooth first cutting line 113 of the uncoated portion 15 can be formed. As long as the first blade 211 can vibrate, such a first vibration generating part 213 can adopt various vibration modes.

[0236] Reference Figures 9 to 11 The second cutting section 220 includes a second blade 221 that cuts the uncoated section 15 in the radial direction and a second vibration generating section 223 for fixing the second blade 221.

[0237] The front end of the second blade 221 can be formed into a straight line. In this case, the aforementioned front end can be provided with a cutting edge. Once the second blade 221 with such a straight front end cuts the second cutting line 16a of the intended cutting portion 115a, it will... Figure 11 As shown, the intended bending portion 117a is configured to form a straight line with the diameter direction of the electrode assembly 110. Furthermore, the inner end portion 115b on the core portion 112 side of the cut surface 115 is formed as a straight line, while the outer end portion 115c is formed as an arc. The inner end portion 115b constitutes the boundary line between the intended bending portion 117a and the cut surface 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode unit body portion 111.

[0238] Furthermore, the front end of the second blade 221 can be formed at an angle to both sides based on its center. In this case, the central angle of the front end of the second blade 221 is greater than or equal to 150° and less than 180°. The aforementioned second blade 221 can be double-edged. That is, the cutting edge can be positioned at a position corresponding to the two inclined sides extending towards the aforementioned front end. Once the second blade 221 with such an inclined front end cuts the second cutting line 16a of the intended cutting portion 115a, it will... Figure 8 As shown, the bending portion 117a is expected to be narrower in width at the center than at the periphery. Furthermore, the central angle θ1 of the inner end portion on the core portion 112 side of the cut surface 115 is greater than or equal to 150° and less than 180°, while the outer end portion is formed in an arc shape. The outer end portion of the cut surface 115 is also formed in an arc shape. The inner end portion 115b forms the boundary line between the expected bending portion 117a and the cut surface 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode unit body portion 111.

[0239] Of course, the central angle of the front end of the second blade 221 can also be greater than 180° and less than or equal to 210°.

[0240] The central angle of the front end of the second blade 221 is formed to be the same as the central angle θ2 of the first blade 211 (refer to...). Figure 7 At the same angle, the first blade 211 moves along the axial direction and forms a first cutting line 113 along the diameter direction in the uncoated portion 15. The second blade 221 cuts the second cutting line 16a of the expected cutting portion 115a in the radial direction so that it meets the first cutting line 113, thus forming a near semi-circular cutting surface 115 on both sides of the straight expected bending portion 117a.

[0241] As the second blade 221 advances radially to form the second cutting line 16a, the sharp tip of the second blade 221 first cuts and enters the center of the expected cutting portion 115a of the uncoated portion 15 in the edge direction. As the second blade 221 advances in the centripetal direction, the double blades 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 larger area of ​​the second blade 221 does not come into contact with the side of the uncoated portion 15 all at once; the force is concentrated at the sharp tip and then applied to the uncoated portion 15. Therefore, when the second cutting line 16a is formed on the side of the uncoated portion 15, the uncoated portion 15 is not pressed and deformed to the side. After the tip first cuts and enters the uncoated portion 15, as the second cutting portion 220 moves in the centripetal direction, the double blades of the second cutting portion 220 apply pressure in the edge direction and cut the second cutting line 16a. The cutting method and direction of this second cutting section 220 minimize the deformation of the uncoated section 15.

[0242] The front end of the second blade 221 can be formed in a shape corresponding to the first blade 211. For example, if the first blade 211 is formed in a straight line, the front end of the second blade 221 can also be formed in a straight line. Furthermore, if the first blade 211 is formed at a certain angle, the front end of the second blade 221 can also be formed at a certain angle. If the first blade 211 is formed in a looping shape, the front end of the second blade 221 can also be formed in a looping shape.

[0243] The second vibration generating unit 223 may include an ultrasonic transducer. The second vibration generating unit 223 performs ultrasonic vibration when the second blade 221 moves radially along the electrode unit body 111 to cut the uncoated portion 15. This increases the cutting speed of the uncoated portion 15, enabling the formation of a smooth cut surface 115. Such a second vibration generating unit 223 can employ various vibration methods, as long as the second blade 221 can be vibrated.

[0244] A recess 112a is formed on one or both sides of the electrode unit body 111 in the axial direction, between the uncoated portion 15 and the core portion 112. The recess 112a is formed in a ring shape surrounding the core portion 112. The radial width W2 of the recess 112a can be formed to be the same as, slightly wider than, or slightly narrower than the height W1 of the uncoated portion 15 (see reference). Figure 9 as well as Figure 10 The recessed portion 112a is formed concentrically with the core portion 112. The recessed portion 112a may be formed on the same plane as the cut surface 115 or slightly lower than the cut surface 115.

[0245] In the uncoated portion 15 of the electrode unit body 111, a pair of cutting lines 113 are provided on the outer side in the radial direction relative to the recess 112a, and can be formed to a predetermined depth in the axial direction.

[0246] The radial width of the recess 112a can correspond to the axial height of the expected bend 117a, measured from the lower end of the cutting line 113 which is arranged adjacent to the recess 112a in the radial direction.

[0247] The cutting depth of the cutting line 113 can reach a predetermined distance from the boundary 16 between the uncoated portion 15 and the coated portion 14 toward the outer side in the axial direction.

[0248] The recessed portion 112a may have a height in the axial direction corresponding to the specified portion.

[0249] The forming portion 117 described above is formed by pressing and laying down the expected bending portion 117a of the uncoated portion 15 disposed between a pair of cut surfaces 115 in a direction intersecting the axial direction, for example, in the radial direction. The forming portion 117 can be formed by pressing and laying down the expected bending portion 117a of the uncoated portion 15 using the stamping portion 230 described below. At this time, the forming portion 117 can be formed by continuously overlapping and laying down a plurality of non-cut pieces constituting the expected bending portion 117a. Thus, relative to the axial direction of the electrode unit body portion 111, the forming portion 117 can be formed at an angle or formed flat after being completely laid down.

[0250] The width of the forming portion 117 is the same. For example, if the front ends of the first blade 211 and the second blade 221 are formed in a straight line, the forming portion 117 can be formed with the same width.

[0251] Furthermore, the width of the core portion 112 side and the width of the periphery of the aforementioned molded portion 117 can be formed differently. For example, at the center angle θ2 of the first blade 211 (refer to...) Figure 7 When the front end of the second blade 221 is inclined, the forming part 117 can be formed such that the width of the core part 112 side is different from the width of the periphery.

[0252] The aforementioned forming portion 117 is the part that forms the current path (current channel) after welding the current collectors 130 and 140. Furthermore, a pair of cut surfaces 115 can also be welded to the current collectors 130 and 140. It should be noted that the cut surfaces 115 are welded to the current collectors 130 and 140 in a line-contact state (e.g., laser welding), so compared to the aforementioned forming portion 117, the effect of the cut surfaces 115 in increasing the current path is not significant. Conversely, the forming portion 117 is formed by bending the intended bending portion 117a along the radial direction, so the forming portion 117 covers the gap between the uncoated portions 15, which are equivalent to the thickness of the separation film 13. This forming portion 117 is welded to the current collectors 130 and 140 in a surface-contact state, so as the area of ​​the forming portion 117 increases, the current path of the electrode assembly 110 and the current collectors 130 and 140 can be relatively increased. The current path is increased by the amount of the gap between the uncoated portions 15, so even when applied to a large-capacity battery cell 100, the heat generation of the battery cell 100 can be suppressed, reducing the possibility of fire.

[0253] If the cut surface 115 is not welded to the current collectors 130 and 140 but is exposed, the impregnation properties of the electrolyte can be improved when the electrolyte is injected into the electrode assembly 110. While bending the uncut sheet may reduce the impregnation properties of the electrolyte at the molded portion 117, the cut surface 115 is adjacent to the molded portion 117, thus compensating for this, and therefore no other problems arise with electrolyte impregnation.

[0254] According to the present invention, in the uncoated portion 15, the planned cutting portion 115a and the planned bending portion 117a are separated in the diametrical direction by a first cutting portion 210 forming a pair of first cutting lines 113 in the axial direction. Then, the lower end of the planned cutting portion 115a is cut by a second cutting portion 220 to form a cutting surface 115. And as the planned bending portion 117a is pressed down, a forming portion 117 is formed. Thus, when the forming portion 117 is formed by pressing the planned bending portion 117a, it is possible to prevent the boundary portion 16 between the forming portion 117 and the cutting surface portion 115 from being torn or irregularly deformed.

[0255] Furthermore, since the boundary 16 between the molded portion 117 and the cut surface 115 can be prevented from tearing or deforming, contact with electrode sheets 11 and 12 of opposite polarity can be prevented in the torn or deformed areas. Moreover, by preventing the boundary 16 between the uncoated portion 15 and the coated portion 14 from tearing or deforming, the active material coated on the coated portion 14 can be prevented from detaching from the coated portion 14 or from weakening its adhesion. Therefore, the reduction in the performance and capacity of the battery cell 100 can be suppressed.

[0256] Furthermore, it can prevent the edges of the separation membrane 13 from warping or being damaged due to tearing or deformation of the boundary portion 16. This prevents short circuits between the first electrode plate 11 and the second electrode plate 12. Moreover, it can reduce the heat generated by the battery cell 100 or significantly reduce the possibility of explosion.

[0257] Furthermore, by applying pressure to the expected bending portion 117a to form the forming portion 117 with the cut surfaces 115 removed from both sides, it is possible to prevent the multiple non-cut pieces of the expected bending portion 117a from tilting and opening due to springback. Moreover, if the expected bending portion 117a is pressed with strong pressure using the stamping portion 230, the forming portion 117 (the multiple non-cut pieces of the expected bending portion 117a) overlaps the cut surfaces 115 in a state of maximum flatness and tightness. Thus, welding with the forming portion 117 and the cut surfaces 115 in surface contact on the current collector plates 130 and 140 significantly increases the weld cross-sectional area. Furthermore, as the weld cross-sectional area increases, the cross-sectional area of ​​the current path increases, resulting in a significant reduction in the resistance of the battery cell 100. This is because resistance is inversely proportional to the cross-sectional area of ​​the current flow path.

[0258] The cut surface 115 can be formed by cutting a portion that separates the uncoated portion 15 and the coated portion 14 by a certain distance in the axial direction. Therefore, the second cutting portion 220 cuts the uncoated portion 15 at a position separating it from the coated portion 14, thus preventing the active material coated on the coated portion 14 from falling off. Furthermore, even if the uncoated portion 15 is slightly deformed and cut, damage or deformation of the coated portion 14 can be prevented.

[0259] The central angle θ1 of the aforementioned cut face 115 (refer to) Figure 8 The diameter of the electrode unit main body 111 and the capacitance of the battery unit 100 can be appropriately selected based on factors such as the diameter of the electrode unit main body 111 and the capacitance of the battery unit 100. For example, the larger the diameter of the electrode unit main body 111, the closer the center angle of the cut surface 115 can be to 150°. This is because a larger diameter of the electrode unit main body 111 increases the cross-sectional area of ​​the current path, which helps prevent overheating or fire. Therefore, in order to increase the area of ​​the molded portion 117, the center angle θ1 of the cut surface 115 is reduced. Furthermore, as the capacitance of the electrode unit main body 111 increases, the center angle of the cut surface 115 can be to be to 150°.

[0260] The molding portion 117 can be shaped such that the intended bending portion 117a of the uncoated portion 15 is laid down towards the core portion 112 of the electrode unit main body portion 111. This prevents the molding portion 117 from protruding outwards from the outer periphery of the electrode unit main body portion 111, allowing the electrode assembly 110 to be smoothly inserted into the battery canister 120 during battery unit 100 manufacturing. Furthermore, it prevents the molding portion 117 from getting stuck in the battery canister 120.

[0261] When the planned bending portion 117a is laid down towards the core portion 112 of the electrode unit main body portion 111, the planned bending portion 117a adjacent to the core portion 112 may obstruct the core portion 112 when it is laid down. That is, as... Figure 1 As shown in (a), when a portion of the uncoated portion 15 is not cut off, the molding portion 117 may cover the core portion 112 as the uncoated portion 15 adjacent to the core portion 112 is laid down.

[0262] The core portion 112 described above sometimes serves as a channel for introducing the electrolyte, and sometimes it can also serve as a channel for inserting the welding rod. Therefore, preferably, the core portion 112 is open in the axial direction. Therefore, as Figure 1 As shown in (b), if the electrode assembly 110 is manufactured as described above with a portion C of the uncoated portion 15 located on the core portion 112 side pre-cut, then as Figure 11 As shown, a recessed portion 112a is formed in such a way that the uncoated portion 15 adjacent to the core portion 112 is removed, and a molded portion 117 is formed in this state, then as Figure 12 As shown, it is expected that the innermost side of the bent portion 117a will overlap with the recessed portion 112a, and there will be no problem of the core portion 112 being blocked.

[0263] A core portion 112 may be formed at the center of the electrode unit main body 111. The core portion 112 is formed into a hollow shape that extends through the center of the electrode unit main body 111. The cross-section of the core portion 112 may be circular. Because the core portion 112 is formed into a hollow shape, after the electrode assembly 110 is inserted into the battery canister 120, the electrolyte injector (not shown) can inject electrolyte through the core portion 112. This shortens the electrolyte injection time, thereby shortening the manufacturing time of the battery unit 100. Furthermore, when the electrolyte injector is inserted into the core portion 112, it prevents the electrode plates 11, 12 or the separation membrane 13 near the core portion 112 from getting stuck and being torn or damaged.

[0264] The electrode unit body 111 can be formed in a cylindrical shape. Therefore, it can be inserted in such a way that the outer side of the electrode unit body 111 is in close contact with the inner side of the cylindrical battery can 120.

[0265] Next, the manufacturing method of the battery cell according to the present invention will be described.

[0266] Figure 14 This is a flowchart illustrating a method for manufacturing a battery cell according to the present invention.

[0267] Reference Figure 14 A separation membrane 13 is stacked between the sheet-like first electrode sheet 11 and the second electrode sheet 12 (S11). The structure comprising the stacked first electrode sheet 11, second electrode sheet 12, and separation membrane 13 is referred to as an electrode stack 10. In the electrode stack 10, the uncoated portion 15 of the first electrode sheet 11 protrudes to one side in the width direction of the electrode stack 10, and the uncoated portion 15 of the second electrode sheet 12 protrudes to the other side in the width direction of the electrode stack 10.

[0268] The first electrode sheet 11, the second electrode sheet 12, and the separation membrane 13 are gel-wound (S12). At this time, the electrode stack 10 is wound onto a winding rod to form an electrode assembly 110, and the winding rod is separated from the electrode assembly 110. At the center of the electrode assembly 110, the portion from which the winding rod is pulled out forms a hollow core portion 112. The core portion 112 is formed to extend through the axial direction of the electrode assembly 110. The more first electrode sheets 11, second electrode sheets 12, and separation membrane 13 are stacked in the electrode stack 10, the shorter the winding time and manufacturing time of the electrode assembly 110 can be.

[0269] Figure 1 The removal of a portion C of the uncoated portion shown in (b) can be performed after the electrode lamination process (S11) and before the winding process (S12). This can be a process of cutting and removing a portion of the uncoated portion 15 by laser cutting.

[0270] The depth at which the uncoated portion 15 is removed in the aforementioned specified interval C and the depth of the aforementioned cutting line 113 can correspond to each other.

[0271] A recess 112a is formed on one or both sides of the electrode unit body 111 in the axial direction, between the uncoated portion 15 and the core portion 112. The recess 112a is formed in a ring shape surrounding the core portion 112. The radial width W2 of the recess 112a can be formed to be the same as the height W1 of the uncoated portion 15, or slightly wider or narrower (see reference). Figure 9 as well as Figure 10 The recessed portion 112a is formed concentrically with the core portion 112. The recessed portion 112a may be formed on the same plane as the cut surface 115 or slightly lower than the cut surface 115.

[0272] The first cutting section 210 moves along 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 side by side along the diametrical direction (S13). At this time, the first cutting section 210 cuts the uncoated portions 15 of the electrode cell body 111 along the axial direction, thereby separating the planned cut section 115a and the planned bend section 117a. A pair of first cutting lines 113 are formed between the planned cut section 115a and the planned bend section 117a, which are parallel to the diametrical direction. At this time, the planned cut section 115a and the planned bend section 117a remain upright along the axial direction of the electrode cell body 111.

[0273] The second cutting section 220 moves along the radial direction of the battery cell 100 to cut the second cutting line of the uncoated portion 15, thereby forming a cut surface 115 (S14). The second cutting section 220 cuts the expected cut portion 115a of the uncoated portion 15 along the radial direction, thereby removing it from the electrode cell body portion 111. As a result, in the uncoated portion 15 of the electrode cell body portion 111, the expected bending portion 117a is arranged on the same straight line as the diameter direction. Furthermore, the cut surface 115 is formed in a semi-circular shape on both sides of the expected bending portion 117a.

[0274] As the stamping section 230 applies pressure, the intended bending portion 117a of the uncoated portion 15 is bent down, thereby forming the molded portion 117 (S15). The molded portion 117 is disposed between the cut surfaces 115 and is formed by bending the intended bending portion 117a of the uncoated portion 15 under pressure. The molded portion 117 can be formed by bending the intended bending portion 117a of the uncoated portion 15 under pressure using the stamping section 230 described below. At this time, the plurality of non-cut pieces constituting the intended bending portion 117a can be continuously overlapped and bent down. As a result, the molded portion 117 can be formed at a slight inclination relative to the axial direction of the electrode unit main body portion 111.

[0275] The cut surface 115 is laser-welded to the current collectors 130 and 140 in a state of contact with the lines, so the cut surface 115 hardly increases the current path. Conversely, the forming portion 117 is formed by laying the intended bending portion 117a in the radial direction, so the forming portion 117 covers a gap equal to the thickness of the uncoated portion 15. This forming portion 117 is welded in a state of contact with the current collectors 130 and 140, so as the area of ​​the forming portion 117 increases, the current path of the electrode assembly 110 and the current collectors 130 and 140 can be relatively increased. This forming portion 117 increases the current path equivalent to adding the area of ​​the uncoated portion 15 gap, so even when applied to a large-capacity battery cell 100, it can suppress the increase in heat generation of the battery cell 100 and reduce the possibility of fire.

[0276] After the planned cutting portion 115a and the planned bending portion 117a are separated in the uncoated portion 15, the planned cutting portion 115a is cut to form the cutting surface 115, and the planned bending portion 117a is bent under pressure to form the shaped portion 117. Thus, when the planned bending portion 117a is bent under pressure to form the shaped portion 117, it is possible to prevent the boundary portion 16 between the shaped portion 117 and the cutting surface 115 from being torn or irregularly skewed and deformed.

[0277] Furthermore, it can prevent the edges of the separation membrane 13 from warping or being damaged due to tearing or deformation of the boundary portion 16. This prevents short circuits between the first electrode plate 11 and the second electrode plate 12. Moreover, it can reduce the heat generated by the battery cell 100 or significantly reduce the possibility of explosion.

[0278] The facets 115 can be formed in a semi-circular shape on both sides of the molding portion 117 of the electrode unit body portion 111. Since the facets 115 are formed in a semi-circular shape, a molding portion 117 can be radially arranged between a pair of facets 115.

[0279] The inner end portion 115b of the core portion 112 of the cut surface 115 is formed as a straight line, and the outer end portion 115c is formed as an arc. The inner end portion 115b forms the boundary line between the intended bending portion 117a and the cut surface 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode unit body portion 111.

[0280] The central angle θ1 of the inner end portion of the cut surface 115 on the core portion 112 side is greater than or equal to 150° and less than 180°, and the outer end portion is formed into an arc shape. Furthermore, the outer end portion of the cut surface 115 is formed into an arc shape. The inner end portion 115b forms the boundary line between the intended bending portion 117a and the cut surface 115. The outer end portion 115c is disposed on the outer peripheral surface of the electrode unit main body portion 111.

[0281] Furthermore, the central angle θ1 of the inner end of the core portion 112 side of the cut face 115 can be formed to be greater than 180° to less than 210°, and the outer end can be formed to be arc-shaped.

[0282] Furthermore, the inner end of the core portion 112 of the cut face 115 can be formed in a loop shape, and the outer end can be formed in an arc shape.

[0283] The cut surface 115 can be separated by a certain distance H (refer to) from the boundary 16 between the uncoated portion 15 and the coated portion 14 in the axial direction outward. Figure 10The second cutting portion 220 cuts the uncoated portion 15 at a position separating it from the coated portion 14, thus preventing the active material coated on the coated portion 14 from falling off. Furthermore, even if the uncoated portion 15 is slightly deformed and cut, damage or deformation of the coated portion 14 can be prevented.

[0284] The molding portion 117 can be formed such that the intended bending portion 117a of the uncoated portion 15 is laid flat towards the core portion 112 of the electrode unit body portion 111. This prevents the molding portion 117 from protruding outwards from the outer peripheral surface of the electrode unit body portion 111, allowing the electrode assembly 110 to be smoothly inserted into the battery canister 120 during battery unit 100 manufacturing. Furthermore, it prevents the molding portion 117 from getting stuck in the battery canister 120.

[0285] The forming portion 117 described above is formed by pressing and laying down the expected bending portion 117a of the uncoated portion 15 disposed between a pair of cut surfaces 115 in a direction intersecting the axial direction, for example, in the radial direction. The forming portion 117 can be formed by pressing and laying down the expected bending portion 117a of the uncoated portion 15 using the stamping portion 230. At this time, the forming portion 117 can be formed by continuously overlapping and laying down a plurality of non-cut pieces constituting the expected bending portion 117a. Thus, relative to the axial direction of the electrode unit body portion 111, the forming portion 117 can be formed at an angle or formed flat after being completely laid down.

[0286] The width of the forming portion 117 is the same. For example, if the front ends of the first blade 211 and the second blade 221 are formed in a straight line, the forming portion 117 can be formed with the same width.

[0287] Furthermore, the width of the core portion 112 side and the width of the periphery of the aforementioned molded portion 117 can be formed differently. For example, at the center angle θ2 of the first blade 211 (refer to...) Figure 7 When the front end of the second blade 221 is inclined, the forming part 117 can be formed such that the width of the core part 112 side is different from the width of the periphery.

[0288] The first cutting section 210 vibrates via the first vibration generating section 213 while simultaneously cutting the uncoated section 15. The first vibration generating section 213 may include an ultrasonic transducer. By vibrating while cutting the uncoated section 15, the first cutting section 210 can improve the cutting performance and cutting speed of the uncoated section 15.

[0289] The second cutting section 220 vibrates via the second vibration generating section 223 while simultaneously cutting the uncoated section 15. The second vibration generating section 223 may include an ultrasonic transducer. Since the second cutting section 220 vibrates while cutting the uncoated section 15, it can improve the cutting performance and speed of the uncoated section 15.

[0290] Preferably, regarding the above-described cutting face 115 processing, the processing performed by the first cutting section 210 is performed first, followed by the processing performed by the second cutting section 220.

[0291] A battery cell manufactured using the electrode assembly described above will be explained.

[0292] Figure 15 This is a cross-sectional view showing the electrode assembly according to the present invention.

[0293] Reference Figure 15 The battery cell 100 according to the present invention includes an electrode assembly 110, a battery canister 120, a sealing cap 150, and a first current collector 130.

[0294] Electrode assembly 110 is essentially the same as described above, so its description is omitted.

[0295] The battery can 120 internally houses the electrode assembly 110. The battery can 120 is electrically connected to either the first electrode plate 11 or the second electrode plate 12, thereby having a first polarity. The battery can 120 can be formed of a conductive material to allow current to flow through it. For example, the battery can 120 can be manufactured of materials including stainless steel, aluminum, etc. The battery can 120 can be formed with one side ( Figure 15 The upper side forms an open-end cylindrical shape.

[0296] The sealing cap 150 seals the open end of the battery can 120. The sealing cap 150 is configured to be insulated from the battery can 120. The sealing cap 150 prevents external impurities or moisture from penetrating into the battery can 120.

[0297] The first current collector 130 is electrically connected to another of the first electrode sheet 11 and the second electrode sheet 12, and has a second polarity. The first current collector 130 can be disposed between the electrode assembly 110 and the sealing cover portion 150. The first current collector 130 is electrically connected to the sealing cover portion 150. The first current collector 130 can be welded to the uncoated portion 15 of the other of the first electrode sheet 11 and the second electrode sheet 12. At this time, the molded portion 117 of the uncoated portion 15 can be welded in a state of surface contact with the first current collector 130, and the cut portion 115 of the uncoated portion 15 can be welded in a state of line contact with the first current collector 130. As a result, the welding cross-sectional area of ​​the uncoated portion 15 and the first current collector 130 is increased, so the cross-sectional area of ​​the current path is increased, which can significantly reduce the resistance of the battery cell 100. Furthermore, the heat generation of the battery cell 100 can be reduced, and the possibility of the battery cell 100 catching fire can be reduced.

[0298] The first electrode 11 can be a negative electrode, and the second electrode 12 can be a positive electrode. Furthermore, the first electrode 11 can be a positive electrode, and the second electrode 12 can be a negative electrode.

[0299] Electrolyte is injected into the battery canister 120 through the core portion 112 of the electrode assembly 110.

[0300] The electrolyte can be of type A + B - Salts with similar structures. Among them, A... + Including Li + Na + K + Ions consisting of basic metal cations or combinations thereof. Additionally, B... - Including the choice of 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 - Any one or more anions that constitute a group.

[0301] The electrolyte can also be used in organic solvents. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0302] The sealing cover 150 may further include an insulator 157, which covers the first current collector plate 130 and has its edge sandwiched between the inner peripheral surface of the support portion 122 and the first current collector plate 130. The insulator 157 provides electrical insulation between the sealing cover 150 and the battery canister 120.

[0303] Insulator 157 can be made of a polymer resin with insulating properties. For example, insulator 157 can be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0304] The sealing cover 150 includes a cover plate 151 disposed to shield the open end of the battery canister 120. The cover plate 151 can be formed entirely in a disc shape. At the center of the cover plate 151, outwards ( Figure 13 The upper side of the terminal 152 protrudes to form an external terminal.

[0305] The sealing cover 150 includes a vent plate 153 disposed on the underside of the cover plate 151. The vent plate 153 ruptures when the internal pressure of the battery canister 120 exceeds a predetermined pressure. Such a vent plate 153 prevents the battery cell 100 from exploding.

[0306] The exhaust plate 153 and the first current collector 130 are electrically connected via the guide portion 155. Furthermore, the exhaust plate 153 contacts the cover plate 151, thereby forming part of the current path.

[0307] A support portion 122 is formed on the lower side of the open end of the battery can 120, which is recessed toward the inside of the battery can 120. An exhaust plate 153 and a cover plate 151 are stacked on the upper side of the support portion 122.

[0308] An insulator 157 is sandwiched between the inner side of the support portion 122 and the edges of the exhaust plate 153 and the cover plate 151. The insulator 157 covers the first current collector plate 130, and its edge is sandwiched between the inner peripheral surface of the support portion 122 and the first current collector plate 130. Such an insulator 157 constitutes part of the sealing cover portion 150.

[0309] A clamping portion 123 is formed at the open end of the battery can 120 to pressurize the cover plate 151 and the insulator 157. The clamping portion 123 is bent inwards towards the open end of the battery can 120, thereby sealing the edge of the cover plate 151 with the open end of the battery can 120. The support portion 122 and the clamping portion 123 press and fix the edges of the first current collector plate 130 and the vent plate 153, thus restricting the movement of the first current collector plate 130 and the vent plate 153, thereby improving the assembly stability of the battery cell 100. Furthermore, it prevents the airtightness of the battery can 120 from leaking due to external impacts.

[0310] Either the first electrode 11 or the second electrode 12 can be electrically connected to the battery canister 120 via the second current collector 140. In this case, the second current collector 140 can be welded to the uncoated portion 15 formed on either the first electrode 11 or the second electrode 12. The cut portion 115 and the formed portion 117 of the uncoated portion 15 and the second current collector 140 can be laser-welded. This increases the welding cross-sectional area of ​​the uncoated portion 15 and the second current collector 140, thus increasing the cross-sectional area of ​​the current path and significantly reducing the resistance of the battery cell 100. Furthermore, it reduces the heat generated by the battery cell 100, lowering the possibility of the battery cell 100 catching fire.

[0311] Furthermore, the uncoated portion 15 formed on either the first electrode sheet 11 or the second electrode sheet 12 can, of course, be directly welded to the inner side of the battery can 120.

[0312] Figure 16 This is a perspective view showing the state of the electrode assembly housing with battery pack according to the present invention.

[0313] Reference Figure 16According to an embodiment of the present invention, the battery pack includes an assembly of cylindrical battery cells 100 electrically connected to each other and a battery pack housing 101 housing the assembly. The cylindrical battery cells 100 can be any one of the cylindrical battery cells 100 according to the above embodiments. In the accompanying drawings, for ease of illustration, components such as busbars (not shown), cooling units (not shown), and external terminals (not shown) for electrically connecting the plurality of cylindrical battery cells 100 are omitted.

[0314] The battery pack can be installed in vehicle 300. For example, vehicle 300 can be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. Vehicles can be four-wheeled or two-wheeled.

[0315] Figure 17 This is a diagram illustrating a vehicle including a battery pack according to the present invention.

[0316] Reference Figure 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 receives power from the battery cell 100 according to an embodiment of the present invention for operation.

[0317] The present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments and drawings disclosed in this specification. It should be understood that various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. Moreover, even if the effects based on the configuration of the present invention are not explicitly described in the above-described embodiments of the present invention, the predictable effects based on the corresponding configuration should be acknowledged.

Claims

1. A cutting device for cutting at least a portion of an uncoated portion (15) of an electrode assembly (110), the electrode assembly (110) being wound up in a state in which a sheet-like first electrode sheet (11), a second electrode sheet (12), and a separation membrane (13) are stacked, and at least one of the first electrode sheet (11) and the second electrode sheet (12) has an uncoated portion (15) without an active material layer at its width-direction end, the cutting device comprising: A first cutting section (210) moves along the axial direction of the electrode assembly (110) and cuts along the axial direction the uncoated portion (15) extending along the axial direction, thereby forming a pair of first cutting lines (113) side by side with the uncoated portion (15) in the diametrical direction; and The second cutting section (220) moves along the radial direction of the electrode assembly (110) and forms a pair of second cutting lines (16a) along the circumferential direction on the uncoated section (15) that is wound in the circumferential direction. The pair of second cutting lines (16a) are respectively connected to the corresponding first cutting lines (113) to cut the uncoated section portion surrounded by the first cutting lines (113) and the second cutting lines (16a), thereby forming a pair of cutting surfaces (115) on the outside of the pair of first cutting lines (113) of the uncoated section (15).

2. The cutting device according to claim 1, wherein, The first cutting portion (210) includes a pair of first blades (211) which are disposed on both sides of the uncoated portion (15) in the diametrical direction and extend in the axial direction.

3. The cutting device according to claim 1, wherein, The first cutting section (210) mentioned above also includes a first vibration generating section (213).

4. The cutting device according to claim 1, wherein, The second cutting section (220) is formed as a quadrilateral with a blade at the end, so as to cut the outer side of the first cutting line (113) of the uncoated section (15).

5. The cutting device according to claim 1, wherein, The second cutting section (220) mentioned above also includes a second vibration generating section (223).

6. An electrode assembly processing apparatus, comprising: The cutting device according to claim 1; as well as The stamping section (230) is pressurized to flatten the uncoated section (15) of the intended bending section (117a) that has not been cut out, thereby forming the molding section (117). The stamping part (230) moves along the radial direction of the electrode assembly (110) to cause the expected bending part (117a) between a pair of first cutting lines (113) of the uncoated part (15) to bend in the radial direction of the electrode assembly (110).

7. A method for manufacturing a battery cell (100), comprising: The steps of stacking and winding the sheet-like first electrode sheet (11), second electrode sheet (12) and separation membrane (13); The first cutting section (210) moves along the axial direction of the battery cell (100) and cuts the uncoated portion (15) of the first electrode sheet (11) and the second electrode sheet (12) along the axial direction to form a pair of first cutting lines (113). The second cutting section (220) moves along the radial direction of the battery cell (100) and forms a pair of second cutting lines (16a) along the circumferential direction on the uncoated portion (15) wound in the circumferential direction, and the pair of second cutting lines (16a) are respectively connected to the corresponding first cutting lines (113), cutting the uncoated portion surrounded by the first cutting lines (113) and the second cutting lines (16a), thereby forming a cutting surface (115) on the outside of the pair of first cutting lines (113) of the uncoated portion (15); and The step of pressing the stamping part (230) to press the expected bending part (117a) between a pair of the first cutting lines (113) of the uncoated part (15) and laying it down in the radial direction to form the molding part (117).

8. The method for manufacturing the battery cell (100) according to claim 7, wherein, The inner end (115b) of the winding shaft side of the cut surface (115) is formed in a straight line shape, and the outer end (115c) is formed in an arc shape.

9. The method for manufacturing the battery cell (100) according to claim 7, wherein, The center angle (θ1) of the inner end (115b) on the winding axis side of the cut face (115) is greater than or equal to 150° and less than 180°, and the outer end (115c) is formed into an arc shape.

10. The method for manufacturing the battery cell (100) according to claim 7, wherein, The forming part (117) is formed along the diameter direction with the winding shaft as the center.

11. The method for manufacturing the battery cell (100) according to claim 7, wherein, The width of the above-mentioned molding part (117) is the same.

12. The method for manufacturing the battery cell (100) according to claim 7, wherein, The forming part (117) is formed such that the width of the winding shaft side is different from the width of the periphery.

13. The method for manufacturing the battery cell (100) according to claim 7, wherein, The forming part (117) is formed in a shape that is laid flat from both sides of the outer periphery of the forming part (117) toward the winding shaft.

14. The method for manufacturing the battery cell (100) according to claim 7, wherein, The cut surface (115) is formed by cutting a portion that is separated from the boundary (16) between the uncoated portion (15) and the coated portion (14) by a certain distance in the axial direction.

15. The method for manufacturing the battery cell (100) according to claim 7, wherein, The first cutting section (210) cuts the uncoated section (15) by vibrating the first vibration generating section (213).

16. The method for manufacturing the battery cell (100) according to claim 7, wherein, The second cutting section (220) cuts the uncoated section (15) by vibrating the second vibration generating section (223).

17. An electrode assembly (110) comprising: The electrode unit main body (111) is formed by stacking a sheet-like first electrode sheet (11), a second electrode sheet (12) and a separation membrane (13) and then rolling them into a gel roll. An uncoated portion (15) without an active material layer is formed at the width direction end of at least one of the first electrode sheet (11) and the second electrode sheet (12). A pair of cut surfaces (115) are formed by cutting off both sides of the uncoated portion (15) in the diameter direction, with the core portion (112) of the electrode unit main body portion (111) as the center. A forming portion (117), disposed between a pair of the aforementioned cut surfaces (115), is formed by pressing down the intended bending portion (117a), which is the portion of the uncoated portion (15) that has not been cut; and The recessed portion (112a) is disposed on the core portion (112) side in the uncoated portion (15) of the electrode unit body portion (111), and has a height that is recessed in the axial direction compared with the uncoated portion (15) disposed on the outer side in the radial direction relative to the recessed portion (112a).

18. The electrode assembly (110) according to claim 17, wherein, The inner end (115b) of the cut surface (115) on the side of the core portion (112) is formed in a straight line shape, and the outer end (115c) is formed in an arc shape.

19. The electrode assembly (110) according to claim 17, wherein, The central angle (θ1) of the inner end (115b) of the cut face (115) on the core part (112) side is formed to be greater than or equal to 150° and less than 180°, and the outer end (115c) is formed to be arc-shaped.

20. The electrode assembly (110) according to claim 17, wherein, The above-mentioned molding part (117) is formed along the diameter direction of the above-mentioned core part (112).

21. The electrode assembly (110) according to claim 17, wherein, The width of the above-mentioned molding part (117) is the same.

22. The electrode assembly (110) according to claim 17, wherein, The aforementioned molding portion (117) is formed such that the width on the side of the aforementioned core portion (112) is different from the width of the periphery.

23. The electrode assembly (110) according to claim 17, wherein, The above-mentioned forming part (117) is formed in a shape that allows the above-mentioned expected bending part (117a) to be laid down along the radial direction of the above-mentioned electrode unit main body part (111).

24. The electrode assembly (110) according to claim 17, wherein, The molding part (117) is formed in a shape that is laid down from both sides of the outer periphery of the molding part (117) toward the core part (112).

25. The electrode assembly (110) according to claim 17, wherein, The cut surface (115) is formed by cutting a portion that is separated from the boundary (16) between the uncoated portion (15) and the coated portion (14) by a certain distance in the axial direction.

26. The electrode assembly (110) according to claim 17, wherein, The core portion (112) is formed into a hollow shape that extends through the center of the electrode unit body portion (111).

27. The electrode assembly (110) according to claim 17, wherein, The main body (111) of the aforementioned electrode unit is formed in a cylindrical shape.

28. The electrode assembly (110) according to claim 17, wherein, Also includes: A pair of cutting lines (113) are provided on the outer side of the uncoated portion (15) of the electrode unit body portion (111) relative to the recessed portion (112a) in the radial direction and are formed to a predetermined depth in the axial direction.

29. The electrode assembly (110) according to claim 28, wherein, The radial width of the recess (112a) corresponds to the axial height of the expected bend (117a) measured from the lower end of the cutting line (113) which is arranged adjacent to the recess (112a) in the radial direction.

30. The electrode assembly (110) according to claim 28, wherein, The cutting depth of the cutting line (113) reaches a predetermined distance from the boundary (16) between the uncoated portion (15) and the coated portion (14) in the axial direction.

31. The electrode assembly (110) according to claim 30, wherein, The recessed portion (112a) has a height in the axial direction corresponding to the specified portion.

32. A battery cell (100) comprising: Electrode assembly (110) according to any one of claims 17 to 31; The battery canister (120) houses the electrode assembly (110) and is electrically connected to either the first electrode plate (11) or the second electrode plate (12) and has a first polarity. A sealing cap (150) seals the open end of the battery canister (120); and The first collector plate (130), which is electrically connected to another of the first electrode plate (11) and the second electrode plate (12), has a second polarity.

33. The battery cell (100) according to claim 32 further comprises: An insulator (157) is sandwiched between the outer periphery of the sealing cover (150) and the inner periphery of the battery can (120), and between the sealing cover (150) and the first current collector (130).

34. A battery pack comprising at least one battery cell (100) as claimed in claim 32.

35. A vehicle comprising at least one battery pack as claimed in claim 34.

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