KR20220140418A - Electrode assembly, cylindrical battery cell, battery cell cutting device and battery pack and vehicle including the same - Google Patents

Abstract

According to the present invention, disclosed are an electrode assembly, a battery cell, a battery cell processing device, a battery pack and a vehicle including the same. The present invention provides an electrode assembly (110) including: a pair of cut surface units (115) formed by cutting both sides of an uncoated unit (15) in a radial direction around a core unit (112) of an electrode cell body unit (111); and a forming unit (117) disposed between the pair of cut surface units (115) and formed by pressing and laying down a unit to be bent (117a) which is a portion where the uncoated unit (15) is not cut.

Description

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

The present invention relates to an electrode assembly, an apparatus for cutting and bending the uncoated area of the electrode assembly, a battery cell including the electrode assembly, and a battery pack and vehicle including the battery cell.

In general, a secondary battery includes a positive electrode, a negative electrode, and an electrolyte, and generates electrical energy using a chemical reaction. Secondary batteries that are easy to apply according to product groups and have electrical characteristics such as high energy density are not only portable devices, but also electric vehicles (EVs) or hybrid vehicles (HEVs) driven by an electric drive source. It is universally applied.

Such a secondary battery has a primary advantage in that it can dramatically reduce the use of fossil fuels. The secondary battery has an advantage in that no by-products are generated according to the use of energy. For this reason, secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency.

The types of secondary batteries currently widely used include a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, and the like. The operating voltage of the unit secondary battery cell, that is, the unit battery cell 100 is about 2.5V to 4.5V. Accordingly, when a higher output voltage is required, a plurality of battery cells are connected in series to form a battery pack. In addition, a plurality of battery cells 100 are connected in parallel to form a battery pack according to the charge/discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack and an electrical connection type may be variously set according to a required output voltage and/or charge/discharge capacity.

On the other hand, as types of unit secondary battery cells, cylindrical, prismatic, and pouch-type battery cells are known. In the case of a cylindrical battery cell, a separator, which is an insulator, is interposed between the positive electrode and the negative electrode and wound to form an electrode assembly in the form of a jelly roll, which is then inserted into the battery can to configure the battery. In addition, a strip-shaped electrode tab may be connected to each of the uncoated regions of the positive electrode and the negative electrode. The electrode tab electrically connects the electrode assembly and the electrode terminal exposed to the outside. For reference, the positive electrode terminal is a cap plate of a sealing body sealing the opening of the battery can, and the negative electrode terminal is the battery can. However, according to the conventional cylindrical battery cell having such a structure, since current is concentrated in the strip-shaped electrode tab coupled to the positive electrode uncoated region and/or the negative electrode uncoated region, resistance is large, heat is generated, and current collection efficiency is poor. There was a problem that it wasn't. That is, the cross-sectional area of the electrode tab is rapidly reduced, which may cause a bottleneck of current flow.

For small cylindrical battery cells with a form factor of 18650 or 21700, resistance and heat are not a big issue. However, when the form factor is increased to apply the cylindrical battery cell to an electric vehicle, a problem may arise in that the cylindrical battery cell ignites as a lot of heat is generated around the electrode tab during the fast charging process.

In order to solve this problem, a cylindrical battery having a structure in which a positive electrode uncoated region and a negative electrode uncoated region are positioned at the top and bottom of the jelly roll type electrode assembly, respectively, and a current collecting plate is welded to the uncoated region to improve current collection efficiency. A cell (so-called Tab-less cylindrical battery cell) is presented.

The first electrode sheet and the second electrode sheet have a structure in which an active material is coated on a current collector in the form of a sheet, and include an uncoated region on one long side along the winding direction.

The electrode assembly is manufactured by sequentially stacking a first electrode sheet and a second electrode sheet together with two separators and then winding them in one direction. At this time, the uncoated portions of the first electrode sheet and the second electrode sheet are arranged in opposite directions.

After the winding process, the uncoated portion of the first electrode sheet and the uncoated portion of the second electrode sheet are bent toward the core. After that, the current collecting plates are welded to each of the uncoated regions to be joined.

Separate electrode tabs are not coupled to the positive uncoated region and the negative uncoated region, the current collecting plate is connected to the external electrode terminal, and the current path is formed with a large cross-sectional area along the winding axis of the electrode assembly, thereby reducing the resistance of the battery cell. There are advantages to lowering it. This is because resistance is inversely proportional to the cross-sectional area of the path through which the current flows.

In the tab-less cylindrical battery cell, in order to improve the welding characteristics between the uncoated region and the current collecting plate, the uncoated region should be bent as flat as possible by applying strong pressure to the welding point of the uncoated region.

However, when the welding point of the uncoated area is bent, the shape of the uncoated area may be irregularly distorted and deformed. In this case, the deformed portion may come into contact with the electrode plate having the opposite polarity to cause an internal short circuit or a fine crack in the uncoated region. In addition, the uncoated region adjacent to the core of the electrode assembly is bent to block all or a substantial portion of the cavity in the core of the electrode assembly. In this case, a problem arises in the electrolyte injection process. That is, the cavity in the core of the electrode assembly is used as a passage through which the electrolyte is injected. However, when the corresponding passage is blocked, it is difficult to inject the electrolyte. In addition, while the electrolyte injector is inserted into the cavity, it may interfere with the uncoated area near the core, resulting in tearing of the uncoated area.

In addition, the bent portion of the uncoated region to which the current collecting plate is welded should be overlapped in multiple layers and there should not be any empty spaces (gaps). Only in this way, sufficient welding strength can be obtained, and even when the latest technology such as laser welding is used, the problem that the laser penetrates into the electrode assembly and damages the separator or the active material can be prevented.

Republic of Korea Patent Publication No. 2022-0023100 (published on March 2, 2022) discloses a cylindrical secondary battery with an improved current collecting structure. Since the cylindrical secondary battery is welded in a state in which the current collecting plate is in line contact with the end of the uncoated region, there is a problem in that a welding cross-sectional area of the current collecting plate and the uncoated region is reduced due to a gap between the uncoated region. Accordingly, since the electric resistance increases in the welding cross-sectional area that is the passage of the current, the amount of heat generated by the battery cell may increase and the possibility of ignition may increase.

Republic of Korea Patent Publication No. 2016-0110610 (2016.09.22) discloses a secondary battery and a cylindrical lithium secondary battery. In such a secondary battery, a configuration is disclosed in which a first current collector plate is electrically connected to be in direct contact with the first uncoated portion, and a second current collector plate is electrically connected to be in direct contact with the second uncoated portion. Also, since the first and second current collecting plates are connected to the ends of the first and second uncoated parts in a state of being in line contact with each other, the contact cross-sectional area of the current collecting plate and the uncoated part is reduced due to the gap between the uncoated parts. there is There is a limit to increasing the contact cross-sectional area.

The present invention has been devised to solve the above problems, and the electrode assembly, battery cell, battery cell cutting device capable of expanding the current path by increasing the welding cross-sectional area of the electrode assembly and the current collecting plate, and a battery pack and vehicle including the same aims to provide

In addition, the present invention provides an electrode assembly, a battery cell, a battery cell cutting device capable of suppressing an increase in the amount of heat generated by the battery cell and reducing the possibility of ignition even when the electrode assembly is applied to a large-capacity battery cell, and a battery pack and vehicle including the same aim to do

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

Another object of the present invention is to provide an electrode assembly structure capable of further increasing an electric capacity compared to a volume of a battery cell, a manufacturing method thereof, and a processing apparatus for manufacturing the same.

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

The technical problems of the present invention are not limited to the above-mentioned purposes, and other objects and advantages of the present invention not mentioned can be understood by the following description, and will be more clearly understood by the examples of the present invention . It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

In order to solve the above problems, the present invention provides an electrode assembly including a first electrode sheet and a second electrode sheet having different polarities, and a jelly-roll type electrode cell body in which a separator for insulation is laminated and wound therebetween. can be applied to

The sheet may be stacked in the order of a first electrode sheet, a separator, a second electrode sheet, and a separator.

The winding may be performed along a longitudinal direction of the stacked sheets. The axial length of the jelly-roll-shaped electrode cell body portion thus formed may correspond to the width of the stacked sheets.

At least one of the first electrode sheet and the second electrode sheet is provided with an uncoated region on which an active material layer is not coated at an end in the width direction. Accordingly, the uncoated portion is provided at the axial end of the electrode cell body. The uncoated portion may be provided on either one side of the axial end of the electrode cell body portion, or provided on both sides.

The uncoated portion of the electrode cell body portion of the electrode assembly includes a pair of cut surface portions formed by cutting out a portion of the uncoated portion. The uncoated part remaining after the part is cut off constitutes the bending scheduled part.

The cut surface part is formed by cutting out both sides of the uncoated part in the radial direction around the core part. The bending scheduled portion is disposed between a pair of cut surface portions.

The electrode assembly includes one forming part formed by bending the bending part.

The cut surface portion may have an inner end portion of the core portion formed in a straight line shape and an outer end portion formed in an arc shape.

The cut surface portion may have a central angle of 150° or more to less than 180° of the inner end of the core portion, and the outer end thereof may be formed in an arc shape.

The cut surface portion may be formed by cutting a portion spaced a predetermined distance outward in the axial direction from a boundary portion between the uncoated portion and the holding portion. That is, it can be said that the cut surface part cuts the uncoated part among the holding part and the uncoated part.

The forming part is formed along a radial direction of the core part.

The forming part may have a straight extension form.

In the circumferential direction of the electrode assembly, the width of the forming portion may be substantially the same.

In the circumferential direction of the electrode assembly, the forming part may be formed to have a width different from a width of the core part and an outer width.

The forming part may be formed in such a way that the bending scheduled part is laid down in a radial direction of the electrode cell body part. The bent portion may be laid down toward the core portion.

Because the forming part is laid down, the axial length of the electrode cell body part can be made more compact. In other words, it is possible to further secure the axial length of the holding part of the electrode cell body to be accommodated in a battery can of the same size. Accordingly, it is possible to secure more electric capacity compared to the volume of the battery cell.

The core part is formed in a hollow shape penetrating the center of the electrode cell body part.

The electrode cell body is formed in a cylindrical shape.

In order to prevent the core part from being blocked by the bent bent part when the bent part is laid down toward the core part, the uncoated part disposed close to the core part among the core part and the outer periphery of the electrode assembly may be removed. . Deletion of the uncoated region may be performed first before the winding process.

That is, in the winding direction, the uncoated portion may be removed in a predetermined section adjacent to the core portion.

When the sheet laminate in the form in which the uncoated area on the core side is removed in this way is wound, the uncoated area near the core has already been removed before the cut surface portion is formed. That is, the bending scheduled portion is also not provided on the core side. Accordingly, even when the bent portion is bent toward the core, the laid-down forming portion does not cover the core portion of the electrode assembly.

The electrode assembly may further include a recess portion disposed on the core portion side in the uncoated portion of the electrode cell body portion and having a height recessed in the axial direction than the uncoated portion disposed radially outward therefrom.

The electrode assembly may further include a plurality of cutting lines provided in a radially outer portion of the uncoated portion of the electrode cell body portion than the recess portion and formed to a predetermined depth in the axial direction.

A radial width of the recess may correspond to an axial height of the planned bending portion measured from a lower end of the cutting line disposed adjacent to the recess in the radial direction.

The cutting depth of the cutting line may reach a predetermined portion spaced apart by a predetermined distance outward in the axial direction from the boundary portion between the uncoated portion and the holding portion.

The recess portion may have a height corresponding to the predetermined portion in an axial direction.

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

the battery cell; a battery can in which the electrode assembly is accommodated and electrically connected to any one of the first electrode sheet and the second electrode sheet to have a first polarity; a sealing cap for sealing the open end of the battery can; and a first current collecting plate having a second polarity electrically connected to the other one of the first electrode sheet and the second electrode sheet.

The first current collecting plate may be electrically connected by being fixed to the forming part of the electrode assembly by welding or the like.

Any one of the first electrode sheet and the second electrode sheet and the battery can may be directly connected or connected through a second current collecting plate.

The battery can may include a supporter that further protrudes inward from the inner periphery of the battery can in a radial direction. The supporter part may support the sealing cap part.

The battery cell may further include an insulator for preventing short circuits of different polarities.

The insulator may be interposed between the battery can and the sealing cap to insulate them. More specifically, the insulator may be interposed between the outer circumferential surface of the sealing cap portion and the inner circumferential surface of the battery can, and may be interposed between the supporter portion and the sealing cap portion.

The insulator may be interposed between the battery can and the first current collecting plate to insulate them. For example, the insulator may be interposed between the first current collecting plate and the supporter part.

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

The present invention provides a vehicle comprising at least one of the battery packs.

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

The cutting device includes: a first cutter part for forming a first cutting line in the axial direction on the uncoated part while moving in the axial direction of the electrode assembly; and a second cutter part forming a second cutting line.

The second cutter part forms a second cutting line for cutting a portion of the uncoated portion wound in the circumferential direction in the circumferential direction, and forms a cutting line such that the second cutting line is connected to the first cutting line.

As the first cutting line and the second cutting line are connected, the uncoated region surrounded by the first cutting line and the second cutting line may be cut off.

The present invention may provide a processing apparatus including the cutting apparatus and a press unit for bending the remaining bending scheduled portion cut out by the cutting apparatus.

The press part forms a forming part according to the laying down by pressing the bending part of the uncoated part.

The bending scheduled portion may be radially pressed by the pressing portion, and accordingly, the bending scheduled portion may be bent in a portion corresponding to the second cutting line and laid down in the radial direction.

The first cutter unit may include a pair of first blades disposed in parallel with the first cutter unit.

The first blade may extend in an axial "direction" and a blade may be formed at an axial tip.

The first cutter unit may further include a first vibration generating unit. The first vibration generator may generate micro vibrations.

The second cutter part may be formed in a rectangular shape to cut a part of the uncoated part in a semicircular shape. The front end of the second cutter may be formed in a straight shape. A blade may be formed at the tip of the second cutter unit.

In addition, the front end of the second cutter may be formed to be inclined with respect to the center. A blade may be formed on two sides provided at the tip of the second cutter unit.

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

The interior angle of the front end may be 150 degrees or more.

The second cutter unit may further include a second vibration generating unit. The second vibration generating unit may generate fine vibrations.

The press unit may be moved in the radial direction (radial direction) of the electrode cell body to lay down the bent portion of the uncoated portion toward the core of the electrode cell body.

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

Such a battery cell manufacturing method includes stacking a first electrode sheet, a second electrode sheet, and a separator, and winding them to fabricate an electrode assembly.

Accordingly, the electrode assembly may include an electrode cell body in which the electrode sheets and separators are wound together.

The electrode cell body may have a cylindrical shape.

The electrode cell body may include a hollow core.

At least one of the first electrode sheet and the second electrode sheet includes an uncoated region on which an active material layer is not applied at one end in the width direction. When both the first electrode sheet and the second electrode sheet have uncoated areas, these uncoated areas may be provided at both ends in the width direction, respectively.

Accordingly, the uncoated portion may be provided at the axial end of the electrode cell body in the form of extending in the axial direction.

In the winding direction, in a predetermined section adjacent to the core portion, the uncoated portion may be deleted.

The deletion of the uncoated region may be performed after the electrode stack is formed and before the winding process. Such processing may be effected, for example, by laser processing.

The deletion of the uncoated region may have already been made in the step of providing the electrode sheet before forming the electrode stack.

The deletion of the uncoated portion may be made after the electrode cell body is formed by winding the electrode stack. Such machining can be effected, for example, by means of a cutter with ultrasonically vibrating blades.

The battery cell manufacturing method includes removing a partial region of the uncoated region provided at the axial end of the electrode cell body.

Specifically, the step of removing the uncoated area includes cutting the uncoated area by a predetermined depth in the axial direction while the first cutter unit moves in the axial direction of the battery cell, thereby forming a first cutting line in the uncoated area in the axial direction. includes

A pair of the first cutting line may be provided. A pair of the first cutting lines may be arranged side by side in the radial direction.

In addition, the step of removing the uncoated area includes forming a second cutting line in the circumferential direction on the uncoated area while the second cutter moves radially inward from the outer periphery of the battery cell after the formation of the first cutting line do.

A pair of the second cutting line may be provided. The second cutting line may extend in a circumferential direction, and a pair of the second cutting lines may be aligned in a radial direction.

The circumferential length of the pair of second cutting lines may gradually increase from the core side to the outer circumference side in the radial direction.

The second cutter part cuts the uncoated part so that the second cutting line is connected to two first cutting lines adjacent in the circumferential direction. Then, the uncoated region surrounded by the second cutting line formed in the circumferential direction and the pair of first cutting lines respectively connected to both ends of the second cutting line may be cut off.

The cut surface portion formed at the position where the uncoated portion is cut off may be formed in a semicircular shape on both sides of the core portion.

The cut surface portion may have an inner end of the core portion) formed in a straight line shape, and an outer end portion thereof may be formed in an arc shape.

The cut surface portion may have a central angle of 150° or more and less than 180° of the inner end of the core portion, and the outer end thereof may be formed in an arc shape.

The method of manufacturing the battery cell may further include a forming part forming step of radially bending and laying down a bent portion, which is an uncoated region remaining after being cut by the cutting lines.

The bending process may be performed by radially pressing the bending scheduled part with a press part.

The forming part may be formed parallel to a radial direction of the electrode cell body part.

The forming part may be formed in such a way that the bending scheduled part of the uncoated part is laid down toward the core part of the electrode cell body part.

The cut surface portion may be formed by cutting a portion spaced a predetermined distance outward in the axial direction from a boundary portion between the uncoated portion and the holding portion.

The first cutter part may cut the uncoated part while vibrating by the first vibration generating part. The first cutter unit may be an ultrasonic cutter.

The second cutter part may cut the uncoated part while vibrating by the second vibration generating part. The second cutter unit may be an ultrasonic cutter.

According to the present invention, since the forming part is welded in a state in which it is in surface contact with the current collecting plate, the current path between the electrode assembly and the current collecting plate may be relatively increased as the area of the forming part is increased.

According to the present invention, since the forming unit increases the current path by the sum of the distances between the uncoated regions, it is possible to suppress an increase in the amount of heat generated by the battery cell and reduce the possibility of ignition even when applied to a large-capacity battery cell.

According to the present invention, after the cutting scheduled portion and the bending scheduled portion are separated from each other in the uncoated portion, the cutting scheduled portion is cut to form a cutting surface portion, and the forming portion is formed by pressing the bending scheduled portion to be laid down. Accordingly, when the forming portion is formed by pressing the bending scheduled portion, the boundary portion between the forming portion and the cut surface portion is torn or deformed while irregularly distorted can be prevented.

According to the present invention, since it is possible to prevent tearing or deformation of the boundary portion of the forming portion and the cut surface portion, it is possible to prevent contact with the electrode sheet of the opposite polarity at the torn or deformed portion.

According to the present invention, since the boundary between the uncoated part and the holding part is prevented from being torn or deformed, it is possible to prevent the active material coated on the holding part from detaching from the holding part or from weakening the bonding force. Accordingly, it is possible to suppress a decrease in the performance and capacity of the battery cell.

According to the present invention, it is possible to prevent the edge of the separation membrane from being lifted or damaged by a torn or deformed portion of the boundary. Accordingly, a short circuit between the first electrode sheet and the second electrode sheet can be prevented. Furthermore, it is possible to reduce the amount of heat generated by the battery cell or significantly reduce the possibility of explosion.

According to the present invention, since the uncoated portion extending in the axial direction of the region not constituting the forming portion is cut to form the cut surface portion, the length occupied by the uncoated portion in the axial direction at both ends of the electrode cell body portion can be reduced. Accordingly, it is possible to further secure the axial volume of the electrode cell body part accommodated in the battery can. Accordingly, the electric capacity relative to the volume of the battery cell may be further increased.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is a plan view schematically showing an electrode cell stack according to the present invention.
2 is a cross-sectional view schematically illustrating a state in which the electrode cell stack of FIG. 1 is cut in the AA direction.
3 is a perspective view schematically illustrating a state in which an electrode cell body part is manufactured by winding the electrode cell stack of FIG. 1 .
4 is a schematic perspective view illustrating a state in which an electrode cell body is cut in a first embodiment of the first cutter according to the present invention.
5 is a plan view showing a first embodiment of the first cutter unit according to the present invention.
6 is a schematic plan view illustrating a state in which the first cutter unit cuts the electrode cell body according to the present invention.
7 is a plan view showing a second embodiment of the first cutter unit according to the present invention.
8 is a schematic plan view showing a state in which the electrode cell body is cut in the second embodiment of the first cutter part according to the present invention.
9 is a perspective view illustrating a state before the second cutter part cuts the uncoated part of the electrode cell body according to the present invention.
10 is a side view illustrating a state in which the second cutter part cuts the uncoated part of the electrode cell body according to the present invention.
11 is a perspective view illustrating a state in which the press unit presses the bending scheduled portion in a state in which the second cutter unit cuts the uncoated portion of the electrode cell body according to the present invention.
12 is a perspective view showing a state in which the pressing part according to the present invention forms a forming part by pressing the bending scheduled part.
13 is a side view showing a state in which the pressing unit according to the present invention forms a forming unit for pressing the bending scheduled portion.
14 is a flowchart illustrating a method of manufacturing a battery cell according to the present invention.
15 is a cross-sectional view illustrating an electrode assembly according to the present invention.
16 is a perspective view illustrating a state in which the electrode assembly according to the present invention is accommodated in the pack housing.
17 is a perspective view illustrating a state in which the battery pack according to the present invention is installed in a vehicle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is not limited to the embodiments disclosed below, and various changes may be made and may be implemented in various different forms. Only this embodiment is provided so as to complete the disclosure of the present invention and to fully inform those of ordinary skill in the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, and all changes and equivalents included in the technical spirit and scope of the present invention as well as substituting or adding the configuration of any one embodiment and the configuration of other embodiments to each other or substitutes.

The accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and scope of the present invention It should be understood to include water or substitutes. In the drawings, in consideration of the convenience of understanding, the size or thickness may be exaggeratedly large or small, but the protection scope of the present invention should not be construed as being limited thereto.

The terms used herein are used only to describe specific embodiments or examples, and are not intended to limit the present invention. And singular expressions include plural expressions unless the context clearly dictates otherwise. In the specification, terms such as includes, consists of, etc. are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist. That is, in the specification, terms such as include and consist of. It should be understood that this does not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

Terms including ordinal numbers such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

When an element is referred to as "over" or "below" another element, it should be understood that other elements may be present in the middle as well as disposed directly on the other element. .

Unless defined otherwise, 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 belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

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

For convenience of description, in the present specification, a direction along the longitudinal direction of the winding shaft of the electrode assembly 110 wound in the form of a jelly roll is referred to as an axial direction (Y). And the direction surrounding the winding shaft is referred to as a circumferential direction (X) or a circumferential direction. And a direction close to the winding axis or away from the winding axis is referred to as a radial direction or a radial direction (Z). Among them, a direction closer to the take-up shaft is referred to as a centripetal direction, and a direction away from the take-up shaft is referred to as a centrifugal direction.

1 is a plan view schematically showing an electrode cell stack according to the present invention, FIG. 2 is a cross-sectional view showing a state in which the electrode cell stack of FIG. 1 is cut in the A-A direction, and FIG. 3 is the electrode cell of FIG. It is a perspective view showing a state in which the electrode cell body part is manufactured by winding the laminate.

1 to 3 , the electrode laminate 10 according to the embodiment of the present invention includes a first electrode sheet 11 , a second electrode sheet 12 , and a separator 13 . The electrode laminate 10 is formed by laminating a separator 13 between the first electrode sheet 11 and the second electrode sheet 12 in the form of a sheet. For example, the electrode laminate 10 may be formed by stacking one first electrode sheet 11 , one second electrode sheet 12 , and two separators 13 . In addition, the electrode laminate 10 may be formed by stacking two or more first electrode sheets 11 , two or more second electrode sheets 12 , and three or more separators 13 . As the number of stacked first electrode sheets 11, second electrode sheets 12, and separators 13 in the electrode stack 10 increases, the winding time and manufacturing time of the electrode assembly 110 having a desired diameter increases. can be shortened.

The first electrode sheet 11 and the second electrode sheet 12 each include a holding portion 14 coated with an active material and an uncoated portion 15 not coated with an active material. The uncoated region 15 may be formed on one side of the first electrode sheet 11 and the second electrode sheet 12 in the width direction. At least a portion of the uncoated region 15 may be used as an electrode tap by itself. When the electrode assembly 110 is wound in a cylindrical shape, the uncoated portion 15 of the first electrode sheet 11 is disposed on one side in the axial direction (upper or lower side in FIG. 1 ), and the uncoated portion 15 of the second electrode sheet 12 is disposed on one side in the axial direction. The part 15 may be disposed on the other side in the axial direction.

The uncoated area 15 of the first electrode sheet 11 and the uncoated area 15 of the second electrode sheet 12 may be formed to have the same width. In addition, the uncoated area 15 of the first electrode sheet 11 and the uncoated area 15 of the second electrode sheet 12 may be formed to have different widths.

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

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

The width of the uncoated portion 15 is significantly narrower than the width of the holding portion 14 . The uncoated region 15 may be formed in a narrow band shape. In addition, the uncoated area 15 may be formed of a plurality of segments spaced apart along the longitudinal direction of the uncoated area 15 and formed in a sawtooth shape. The shape of the segment may be changed to a quadrangle, a triangle, a semicircle, a semiellipse, a parallelogram, or the like.

The uncoated region 15 may have a form in which a portion C close to the core is deleted. The corresponding section may be removed through laser processing or the like before winding after the electrode stack 10 is formed.

Of course, in the electrode sheet providing step, the uncoated area of the corresponding section (C) may be deleted in advance, or the core-side uncoated area removal area 112a may be formed through post-processing after winding.

In the present invention, the positive active material coated on the first electrode sheet 11 and the negative active material coated on the second electrode sheet 12 may be used without limitation as long as the active material is known in the art.

The positive active material may include a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxide (LiMnO ₂ ), such as Formula Li _1+x Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ ; lithium copper oxide (Li ₂ CuO ₂ ); vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; lithiated nickel represented by the formula LiNi _1-x M _x O ₂ , where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3 oxide); Formula LiMn _2-x M _x O ₂ where M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1 or Li ₂ Mn ₃ MO ₈ , where M = Fe, Co, lithium manganese composite oxide represented by Ni, Cu or Zn; LiMn ₂ O ₄ in which a part of lithium in the formula is substituted with an alkaline earth metal ion; disulfide compounds; A lithium intercalation material may be a main component, such as a composite oxide formed by Fe ₂ (MoO ₄ ) ₃ or a combination thereof. The positive active material includes the above types, but is not limited thereto.

The positive electrode current collector has a thickness of, for example, 3 to 500 μm. The positive electrode current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, as the positive electrode current collector, stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface treatment of aluminum or stainless steel with carbon, nickel, titanium, silver, or the like may be used. The electrode current collector may increase the adhesion of the positive electrode active material by forming fine irregularities on the surface thereof. Such an electrode current collector may have various forms such as a film, a sheet, a foil, a net, a porous body, a foam body, a nonwoven body, and the like.

A conductive material may be additionally mixed with the positive active material particles. The conductive material is added, for example, in an amount of 1 to 50% by weight based on the total weight of the mixture including the positive active material. The conductive material is not particularly limited as long as it has high conductivity without causing a chemical change in the battery. For example, the conductive material may include graphite such as natural graphite and artificial graphite; carbon black, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskeys such as zinc oxide and potassium titanate; conductive oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives may be used.

In addition, the negative electrode sheet is manufactured by coating and drying negative electrode active material particles on the negative electrode current collector, and if necessary, the above-described components such as a conductive material, a binder, a solvent, etc. may be further included.

The negative electrode current collector has a thickness of, for example, 3 to 500 μm. Such a negative current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, the negative electrode current collector may be copper, stainless steel, aluminum, nickel, titanium, calcined carbon, a copper or stainless steel surface treated with carbon, nickel, titanium, silver, etc., an aluminum-cadmium alloy, etc. can In addition, like the positive electrode current collector, the bonding strength of the negative electrode active material can be strengthened by forming fine irregularities on the surface, and it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, nonwovens, and the like.

The negative active material may include, for example, carbon such as non-graphitizable carbon or graphitic carbon; Li _x Fe ₂ O ₃ (0≤x≤1), Li _x WO ₂ (0≤x≤1), Sn _x Me _1-x Me'yO _z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of Groups 1, 2, and 3 of the periodic table, halogen; lithium metal; lithium alloy; silicon-based alloys; tin-based alloys; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , oxides such as Bi ₂ O ₅ ; conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The binder polymer usable for the electrode sheets 11 and 12 is a component that assists in bonding of the electrode active material particles and the conductive material and bonding to the electrode current collector, for example, based on the total weight of the mixture containing the electrode active material. 1 to 50% by weight. Examples of the binder polymer include polyvinylidene fluoride-co-hexafluoropropylene (PVdF), polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate (polymethylmethacrylate), polybutylacrylate, lyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, ethylene-co-vinyl acetate, Polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, Any one binder selected from the group consisting of cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan and carboxyl methyl cellulose A polymer or a mixture of two or more thereof may be used, but the present invention is not limited thereto.

Non-limiting examples of the solvent used for preparing the electrode include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2 -Pyrrolidone (N-methyl-2-pyrrolidone, NMP), cyclohexane (cyclohexane), water, or a mixture thereof, and the like. These solvents provide an appropriate level of viscosity so that the slurry application layer can be made at a desired level for the electrode current collector surface.

The separator 13 has a porous polymer substrate and a porous coating layer positioned on both sides of the porous polymer substrate and including inorganic particles and a binder polymer.

The porous polymer substrate may be a polyolefin-based porous substrate.

The polyolefin porous substrate may be in the form of a film or a non-woven web. By having the porous structure as described above, the electrolyte can be smoothly moved between the anode and the cathode. The porous structure also increases the electrolyte impregnation property of the substrate itself, so that excellent ion conductivity can be secured, and resistance increase inside the electrochemical device is prevented, thereby preventing the performance degradation of the electrochemical device.

The polyolefin porous substrate used in the present invention can be used as long as it is a planar porous substrate commonly used in electrochemical devices, and the material or shape thereof can be variously selected according to the purpose.

The polyolefin porous substrate may be, but is not limited to, a film or a 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, The present invention is not limited thereto.

The polyolefin porous substrate may have a thickness of 8 to 30 μm, but this is only an example, and a thickness outside the above range may be adopted in consideration of mechanical properties or high-efficiency charge/discharge characteristics of the battery.

The separator 13 according to the present invention may have a thickness of 1 to 100 μm or 5 to 50 μm. If the thickness of the separator 13 is less than 1 μm, the function of the separator 13 may not be sufficiently exhibited and deterioration of mechanical properties may occur. If the thickness of the separator 13 is greater than 100 μm, characteristics of the battery may be deteriorated during high-rate charge/discharge. In addition, it may have a porosity of 40 to 60%, and may have a permeability of 150 to 300 sec/100 mL.

When the separator 13 according to an embodiment of the present invention is used, since the porous coating layer is provided on both sides of the porous polymer substrate, a uniform solid electrolyte interfacial layer can be formed by improving the impregnation performance with respect to the electrolyte. It is possible to secure superior air permeability compared to the single-sided inorganic coating separator 13 of the. For example, it may be within 120s/100cc. In addition, even if the inorganic porous coating layer is provided on both sides, the thickness of the conventional single-sided inorganic coating separator 13 can be realized. For example, it may be within ~15.0 μm.

기준 5% 이내의 열수축 특성을 갖는 내열 특성을 확보할 수 있고, 550gf 이상의 관통 강도(Puncture strength) 물성을 확보할 수 있으며, 이러한 분리막(13)을 채용한 전지의 사이클 중 코어 변형(core deformation) 발생 시 단차부에서 분리막(13)의 손상 또는 관통이 방지될 수 있다.In addition, when the separator 13 according to an embodiment of the present invention is used, the stability of the separator 13 is improved to ensure heat resistance and compression resistance. specifically 180

It is possible to secure heat resistance characteristics with heat shrinkage characteristics within 5% of the standard, and to secure puncture strength properties of 550 gf or more, and core deformation during the cycle of a battery employing such a separator 13 . In the event of occurrence, damage or penetration of the separation membrane 13 in the step portion may be prevented.

An electrode assembly 110 manufactured using the above-described electrode stack 10 will be described.

4 is a schematic perspective view showing a state in which the electrode cell body is cut in the first embodiment of the first cutter unit according to the present invention, and FIG. 5 is a plan view showing the first embodiment of the first cutter unit according to the present invention. , FIG. 6 is a schematic plan view showing a state in which the first cutter unit according to the present invention cuts the electrode cell body, FIG. 7 is a plan view showing a second embodiment of the first cutter unit according to the present invention, FIG. 8 is a schematic plan view showing a state in which the electrode cell body is cut in the second embodiment of the first cutter unit according to the present invention, and FIG. 9 is a state before the second cutter unit according to the present invention cuts the uncoated part of the electrode cell body. 10 is a side view illustrating a state in which the second cutter unit cuts the uncoated region of the electrode cell body according to the present invention. 11 is a perspective view illustrating a state in which the press unit presses the bending scheduled portion in a state in which the second cutter unit cuts the uncoated portion of the electrode cell body according to the present invention, and FIG. It is a perspective view showing a state in which a part is formed, and FIG. 13 is a side view showing a state in which the pressing part according to the present invention forms a forming part for pressing the bending scheduled part.

4 to 13 , the electrode assembly 110 includes an electrode cell body part 111 , a plurality of cut surface parts 115 , and a plurality of forming parts 117 .

The electrode cell body 111 is a cylindrical portion wound in a jelly roll type in a state in which the separator 13 is stacked between the first electrode sheet 11 and the second electrode sheet 12 in the form of a sheet. to be. As described above, the uncoated area 15 on which the active material layer is not coated is formed on the width direction ends of the first electrode sheet 11 and the second electrode sheet 12 , and these are the electrode cell body portions 111 , respectively. It is disposed on one side and the other side in the axial direction, respectively, and extends in the axial direction.

The electrode cell body portion 111 may be formed by winding the electrode stack body 10 elongated in the longitudinal direction around a winding rod (not shown), and taking the winding rod out of the electrode cell body portion 111 . In this case, the more the first electrode sheet 11 , the second electrode sheet 12 , and the separator 13 are stacked on the electrode stack 10 , the shorter the winding time and the manufacturing time of the electrode assembly 110 . A position from which the winding rod exits from the electrode cell body part 111 constitutes a hollow core part 112 .

The uncoated part 15 of the first electrode sheet 11 is exposed at a certain height on one side of the electrode cell body 111 in the axial direction, and the second electrode sheet 12 is on the other side of the electrode cell body 111 in the axial direction. of the uncoated area 15 is exposed at a predetermined height.

In addition, the recess portion 112a is provided in the uncoated area section adjacent to the core portion 112 by the uncoated area deletion region C described above.

The first cutter part 210 cuts the uncoated part 15 of the electrode cell body part 111 in the axial direction to separate the cutting scheduled part 115a and the bending scheduled part 117a in the circumferential direction. A first cutting line 113 is formed between the cutting scheduled portion 115a and the bending scheduled portion 117a. The first cutting line 113 is formed in a form (vertical form) extending from the axial end of the uncoated region 15 toward the electrode cell body 111 in the axial direction. At this time, the cutting scheduled portion 115a and the bending scheduled portion 117a maintain a standing state along the axial direction of the electrode cell body portion 111 as it is.

The second cutter part 220 removes the cut scheduled part 115a from the electrode cell body part 111 by radially cutting the axial lower part of the cut part 115a of the uncoated part 15 . The second cutter part 220 forms a second cutting line 16a extending in the circumferential direction under the uncoated part 15 in the area corresponding to the part to be cut 115a. The second cutting lines 16a are formed along the circumferential direction of the uncoated area 15 and are respectively provided below the uncoated areas adjacent to each other in the radial direction. When both ends of the second cutting line 116a in the circumferential direction are connected to the first cutting lines 13 on both sides of the cutting scheduled portion 115a in the circumferential direction, the pair of first cutting lines 13 and The cutting scheduled portion 115a surrounded by the second cutting line 116a is separated from the electrode cell body 111 . The short uncoated region remaining after the cutting scheduled portion 115a constitutes the cut surface portion 115 .

Accordingly, the cut surface portion 115 and the bent portion 117a are provided in the uncoated portion 15 of the electrode cell body portion 111 .

An ultrasonic cutter may be used for the first cutter part 210 for cutting the first cutting line 113 to prevent buckling that may occur when the thin uncoated part 15 is cut in the axial direction. .

The first cutter unit 210 includes a pair of first blades 211 disposed side by side on both sides of a position corresponding to a diameter portion of the electrode cell body 111, and the first blade 211, respectively. and a pair of fixed first vibration generating units 213 . One first blade 211 is fixed to each of the first vibration generating units 213 .

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

The first blade 211 has a proximal end fixed to the plate surface of the first vibration generating unit 213, extending in a direction corresponding to the axial direction of the electrode cell body 110, and a sharp blade at the distal end. can be provided.

The pair of first blades 211 are disposed in the corresponding first vibration generating unit 213 symmetrically with respect to the diameter portion of the electrode cell body 110 . Examples related thereto will be described as follows.

4 to 6 , a pair of first blades 211 defining the bent portion 117a are arranged in a straight line on both sides of the diameter based on the diameter portion of the electrode cell body portion 210 . can be In this case, the pair of first blades 211 are disposed at the same distance from the diameter portion of the electrode cell body 210 . Accordingly, when the pair of first blades 211 cut the uncoated area 15 of the electrode cell body 210 , the first cutting line 113 of a straight line is formed on both sides of the diameter portion of the uncoated area 15 . can form.

The above embodiment exemplifies a structure in which a pair of first blades 211 defining the bent portion 117a are arranged parallel to each other. However, the pair of first blades 211 are not necessarily parallel to each other. For example, the pair of first blades 211 may have a form that gradually moves away from each other toward the distal end, or a form that gradually moves away from each other toward the centripetal direction. Also, although the first blade 211 is exemplified to be linear, the first blade 211 is not necessarily linear. For example, the first blade 211 may have a gentle curved shape.

In addition, in the above embodiment, a pair of first blades 211 defining the bending scheduled portion 117a exemplifies a structure in which each of the pair of first vibration generators 213 is fixed. However, the pair of first blades 211 may be fixed together to one first vibration generating unit 213 .

Also, in the above embodiment, a method is exemplified in which a pair of first blades 211 defining the bent portion 117a simultaneously cut the uncoated portion. However, this does not exclude a method in which one first blade 211 processes either one of both sides of the diameter portion of the electrode cell body 210 first and then processes the other.

In addition, although the embodiment illustrates that the first blade 211 is in the form of a single blade extending straight and continuously, the blade may be discontinuous in the section (eg, the core section) in which the uncoated section is not cut anyway. .

Referring to FIGS. 7 and 8 , the pair of first blades 211 are disposed to be inclined at a predetermined angle based on the diameter of the electrode cell body 210 . In this case, the outer inclination angle θ2 of the first blade 211 may be formed to be 150° or more and less than 180°. Accordingly, when the pair of first blades 211 cut the uncoated area 15 of the electrode cell body 210 , the first cutting line 113 is inclined on both sides of the diameter of the uncoated area 15 . can form.

Of course, the outer inclination angle θ2 of the first blade 211 may be formed to be greater than 180° and less than or equal to 210°. The angle of the pair of first blades 211 may be appropriately selected according to the diameter of the electrode cell body 111 or the capacity of the battery pack, and the shape of the current collecting plates 130 and 140 to be welded thereto.

The above embodiment illustrates a structure in which a pair of first blades 211 defining the bent portion 117a are inclined symmetrically with respect to the center of the core portion 112 . However, it is not necessary that the pair of first blades 211 have a symmetrically inclined structure with respect to the center of the core part 112 . For example, the pair of first blades 211 may be formed at different angles from the center of the core part 112 toward the centripetal side. Also, although the first blade 211 is exemplified to be linear, the first blade 211 is not necessarily linear. For example, the first blade 211 may be in the form of a gentle curve toward the core 112 or the opposite side.

The first vibration generator 213 may include an ultrasonic vibrator. The first vibration generating unit 213 is ultrasonically vibrated when the first blade 211 is moved in the axial direction of the electrode cell body 111 to cut the uncoated region 15 .

When the first blade 211 presses the uncoated area 15 without the force of the first blade 211 pressing the uncoated area 15 in the axial direction to process the first cutting line 113 , the uncoated area 15 ) There is a possibility of buckling or deformation such as bending or folding of the uncoated region 15 near the first cutting line 113 .

When the first blade 211 vibrates ultrasonically, when the first blade 211 cuts the uncoated area 15 , the above phenomenon is prevented and the cutting process is performed very smoothly. Accordingly, the cutting speed of the uncoated area 15 may be improved, and the first cutting line 113 of the uncoated area 15 may be smoothly formed. As long as the first vibration generating unit 213 vibrates the first blade 211, various vibration methods may be applied.

9 to 11 , the second cutter unit 220 includes a second blade 221 that cuts the uncoated area 15 in a radial direction, and a second vibration generator to which the second blade 221 is fixed. (223).

The front end of the second blade 221 may be formed in a straight shape. At this time, the tip may be provided with a blade. When the second blade 221 having such a straight tip portion cuts the second cutting line 16a of the cutting scheduled portion 115a, the bending scheduled portion 117a is moved in the radial direction of the electrode cell assembly 110 as shown in FIG. 11 . placed in a straight line with In addition, in the cut surface portion 115 , the inner end 115b of the core portion 112 side is formed in a straight shape, and the outer end 115c is formed in an arc shape. The inner end portion 115b forms a boundary line between the bent portion 117a and the cut surface portion 115 . The outer end 115c is disposed on the outer circumferential surface of the electrode cell body 111 .

In addition, the front end of the second blade 221 may be inclined to both sides with respect to the center thereof. At this time, the central angle of the front end of the second blade 221 is formed to be 150° or more to less than 180°. The second blade 221 may be double-edged. That is, the blade may be provided at positions corresponding to the two hypotenuses extending to the tip. When the second blade 221 having an inclined tip portion cuts the second cutting line 16a of the cutting scheduled portion 115a, as shown in FIG. It is formed narrower than the width of the side. In addition, the cut surface portion 117a has a central angle θ1 of 150° to less than 180° of the inner end of the core portion 112 side, and the outer end thereof is formed in an arc shape. In addition, the outer end of the cut surface portion 117a is formed in a circular arc shape. The inner end portion 115b forms a boundary line between the bent portion 117a and the cut surface portion 115 . The outer end 115c is disposed on the outer circumferential surface of the electrode cell body 111 .

Of course, the central angle of the front end of the second blade 221 may be formed to be greater than 180° to 210° or less.

The central angle of the front end of the second blade 221 is formed at the same angle as the central angle θ2 (refer to FIG. 7 ) of the first blade 211 described above. Accordingly, as the first blade 211 is moved in the axial direction, a first cutting line 113 is formed in the uncoated region 15 in a radial direction, and the second blade 221 is connected to the first cutting line 113 and When the second cutting line 16a of the cutting scheduled portion 115a is cut in the radial direction to meet, the cut surface portions 115 are formed close to a semicircular shape on both sides of the straight bending planned portion 117a.

When the second blade 221 advances in the radial direction to form the second cutting line 16a, the sharp tip of the second blade 221 is the first cut portion 115a of the uncoated portion 15. The central part in the circumferential direction is cut and entered, and as the second blade 221 proceeds in the centripetal direction, the two blades expand the second cutting line 16a to both sides in the circumferential direction. When the second blade 221 applies a force to the side surface of the uncoated area 15 in the radial direction, the large area of the second blade 221 does not touch the side surface of the uncoated area 15 at once, and the force is applied to the sharp tip. It is concentrated and applied to the uncoated area 15 . Accordingly, in forming the second cutting line 16a on the side surface of the uncoated area 15 , the uncoated area 15 is not deformed by being pressed laterally. Once the tip part cuts the uncoated part 15 and enters, as the second cutter part 220 moves in the centripetal direction, both edges of the second cutter part 220 press the second cutting line 16a in the circumferential direction. and proceed with incision. The cutting method and cutting direction of the second cutter part 220 minimizes deformation of the uncoated part 15 .

The tip of the above-described second blade 221 may be formed in a shape corresponding to that of the first blade 211 . For example, when the first blade 211 is formed in a straight shape, the front end of the second blade 221 may also be formed in a straight shape. In addition, when the first blade 211 is formed at a predetermined angle, the front end of the second blade 221 may also be formed at a predetermined angle. When the first blade 211 is formed to be rounded, the front end of the second blade 221 may also be formed to be rounded.

The second vibration generator 223 may include an ultrasonic vibrator. The second vibration generating unit 223 is ultrasonically vibrated when the second blade 221 is moved in the radial direction of the electrode cell body 111 to cut the uncoated area 15 . Accordingly, the cutting speed of the uncoated area 15 may be improved, and the cut surface portion 115 may be formed smoothly. As long as the second vibration generating unit 223 vibrates the second blade 221 , various vibration methods may be applied.

A recess portion 112a is formed between the uncoated portion 15 and the core portion 112 on one or both sides of the electrode cell body portion 111 in the axial direction. The recessed portion 112a is formed in an annular shape to surround the core portion 112 . The radial width W2 of the recess portion 112a may be the same as the height W1 of the uncoated portion 15 , or may be slightly wider or narrower (see FIGS. 9 and 10 ). The recessed portion 112a is formed to be concentric with the core portion 112 . The recessed portion 112a may be formed flush with or slightly lower than the cut surface portion 115 .

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

The radial width of the recess portion 112a is the axial height of the bent portion 117a measured from the lower end of the cutting line 113 disposed adjacent to the recess portion 112a in the radial direction. can respond with

The cutting depth of the cutting line 113 may reach a predetermined portion spaced apart by a predetermined distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 .

The recess portion 112a may have a height corresponding to the predetermined portion in the axial direction.

The forming part 117 is formed by pressing and laying down the planned bending part 117a of the uncoated part 15 disposed between the pair of cut surface parts 115 in a direction crossing the axial direction, for example, in a radial direction. do. The forming part 117 may be formed by pressing the bending part 117a of the uncoated part 15 using a press part 230 to be described below and then laying it down. At this time, the forming unit 117 may be laid down while continuously overlapping a plurality of non-cut pieces constituting the planned bending unit 117a. Accordingly, the forming portion 117 may be formed to be inclined with respect to the axial direction of the electrode cell body portion 111 or to be completely flattened.

The width of the forming part 117 is formed to be the same. For example, when the front ends of the first blade 211 and the second blade 221 are formed in a straight line, the forming portion 117 may be formed to have the same width.

In addition, the forming part 117 may be formed to have a different width from the width of the core part 112 side. For example, when the central angle θ2 of the first blade 211 (see FIG. 7 ) and the tip of the second blade 221 are formed to be inclined, the forming unit 117 is formed between the width and the outer edge of the core unit 112 . different widths are formed.

The forming part 117 is a part that is welded to the current collecting plates 130 and 140 to form a current path (current path). Additionally, a pair of cut surface portions 115 may also be welded to the current collecting plates 130 and 140 . However, since the cut surface part 115 is welded (eg, laser welding) to the current collecting plates 130 and 140 in a state of being in line contact with the current collecting plates 130 and 140 , the cut surface part 115 is a current path in comparison with the forming part 117 . The effect of increasing the On the other hand, since the forming portion 117 is formed by laying down the bending portion 117a in the radial direction, the forming portion 117 covers the gap between the uncoated portions 15 spaced apart by the thickness of the separator 13 . Since the forming part 117 is welded in surface contact with the current collecting plates 130 and 140 , the current path between the electrode assembly 110 and the current collecting plates 130 and 140 is relatively increased as the area of the forming part 117 increases. can be Since the forming unit 117 increases the current path by the sum of the distances between the uncoated regions 15 , even when applied to the large-capacity battery cell 100 , the increase in the amount of heat generated by the battery cell 100 is suppressed and the possibility of ignition is reduced. can do it

When the cut surface portion 115 is exposed without being welded to the current collecting plates 130 and 140 , the electrolyte impregnability may be increased when the electrolyte is injected into the electrode assembly 110 . By bending the non-cut piece, the impregnation of the electrolyte may be weakened in the forming portion 117, but the cut surface portion 115 is adjacent to the forming portion 117 and compensates for this. No problem.

According to the present invention, in the uncoated region 15 , the cutting scheduled portion 115a and the bending scheduled portion 117a are formed by the first cutter portion 210 forming a pair of first cutting lines 113 in the axial direction. After being separated in the radial direction, the lower end of the cut portion 115a is cut with the second cutter portion 220 to form the cut surface portion 115, and the forming portion ( 117) is formed. Accordingly, when the forming portion 117 is formed by pressing the bending portion 117a, the boundary portion 16 between the forming portion 117 and the cut surface portion 115 is torn or irregularly distorted to prevent deformation. can

In addition, since the boundary portion 16 of the forming portion 117 and the cut surface portion 115 can be prevented from being torn or deformed, it is prevented from contacting the electrode sheets 11 and 12 of the opposite polarity at the torn or deformed portion. can do. In addition, by preventing the boundary portion 16 between the uncoated portion 15 and the holding portion 14 from being torn or deformed, it is possible to prevent the active material coated on the holding portion 14 from being detached from the holding portion 14 or from weakening the bonding force. can be prevented Accordingly, it is possible to suppress a decrease in performance and capacity of the battery cell 100 .

In addition, it is possible to prevent the edge of the separator 13 from being lifted or damaged by the torn or deformed portion of the boundary portion 16 . Accordingly, a short circuit between the first electrode sheet 11 and the second electrode sheet 12 can be prevented. Furthermore, it is possible to reduce the amount of heat generated by the battery cell 100 or significantly reduce the possibility of explosion.

In addition, since the forming part 117 is formed by pressing the bending part 117a in a state in which the cut surface parts 115 are removed on both sides of the bending part 117a, the non-cutting pieces of the bending part 117a are springs. It can be prevented from unfolding while erected at an angle due to the spring back phenomenon. In addition, when the bending portion 117a is pressed with a strong pressure using the press portion 230 , the forming portion 117 (non-cut pieces of the bending portion 117a) is as flat as possible on the cut surface portion 115 . It can be overlapped in a close-fitting state. Accordingly, as the forming part 117 and the cutting surface part 115 are welded in a state in which they are in surface contact with the current collecting plates 130 and 140 , the welding cross-sectional area may be significantly increased. In addition, as the cross-sectional area of the welding is increased, the cross-sectional area of the current path is increased, so that the resistance of the battery cell 100 can be significantly reduced. This is because resistance is inversely proportional to the cross-sectional area of the path through which the current flows.

The cut surface portion 115 may be formed by cutting a portion 16a spaced a predetermined distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 . Accordingly, since the second cutter part 220 cuts the uncoated part 15 at a position spaced apart from the holding part 14 , it is possible to prevent the active material coated on the holding part 14 from being detached. In addition, even if the uncoated portion 15 is slightly deformed and cut, it is possible to prevent the holding portion 14 from being damaged or deformed.

The central angle θ1 (refer to FIG. 8 ) of the cut surface portion 115 may be appropriately selected in consideration of the diameter of the electrode cell body portion 111 and the capacity of the battery cell 100 . For example, as the diameter of the electrode cell body portion 111 increases, the central angle of the cut surface portion 115 may be formed closer to 150°. This is because the larger the diameter of the electrode cell body 111 is, the greater the cross-sectional area of the current path is to prevent heat generation or ignition. will make it In addition, as the capacity of the electrode cell body portion 111 increases, the central angle of the cut surface portion 115 may be formed closer to 150°.

The forming part 117 may be formed in such a way that the bent part 117a of the uncoated part 15 is laid down toward the core part 112 of the electrode cell body part 111 . Accordingly, since the forming part 117 is prevented from protruding outward from the outer circumferential surface of the electrode cell body part 111 , the electrode assembly 110 is smoothly installed inside the battery can 120 when the battery cell 100 is manufactured. can be put in In addition, it is possible to prevent the forming unit 117 from being caught in the battery can 120 .

When the bent portion 117a is laid down toward the core portion 112 of the electrode cell body 111, the core portion 112 is covered when the bent portion 117a adjacent to the core portion 112 is laid down. This can happen. That is, as the uncoated area 15 adjacent to the core part 112 is laid down in a state in which a partial section of the uncoated area 15 is not cut as shown in FIG. 1A , the forming unit 117 forms the core. The portion 112 may be covered.

The core part 112 may be a passage through which the electrolyte is injected, or in some cases, a passage through which the welding rod is inserted. Accordingly, it is preferable that the core part 112 is open in the axial direction. Accordingly, as shown in (b) of FIG. 1 , the electrode assembly 110 is removed as described above in a state in which the partial section C of the uncoated region 15 positioned on the core portion 112 side is cut in advance. When fabricated, as shown in FIG. 11 , a recessed portion 112a in a form in which the uncoated portion 15 adjacent to the core portion 112 is removed is formed, and when the forming portion 117 is formed in this state, 12 , the innermost portion of the bent portion 117a overlaps the recess portion 112a so that the core portion 112 is not covered.

A core part 112 may be formed in the center of the electrode cell body part 111 . The core part 112 is formed in a hollow shape penetrating the center of the electrode cell body part 111 . The cross-section of the core part 112 may be circular. Since the core part 112 is formed in a hollow shape, after the electrode assembly 110 is put into the battery can 120 , an electrolyte injector (not shown) may inject an electrolyte solution through the core part 112 . Accordingly, since the electrolyte injection time can be shortened, the manufacturing time of the battery cell 100 can be shortened. In addition, when the electrolyte injector is inserted into the core part 112 , it is possible to prevent the electrode sheets 11 and 12 or the separator 13 near the core part 112 from being caught and torn or damaged.

The electrode cell body 111 may be formed in a cylindrical shape. Accordingly, it can be inserted so that the outer surface of the electrode cell body part 111 is in close contact with the inner surface of the cylindrical battery can 120 .

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

14 is a flowchart illustrating a method of manufacturing a battery cell according to the present invention.

Referring to FIG. 14 , a separator 13 is laminated between the first electrode sheet 11 and the second electrode sheet 12 in the form of a sheet ( S11 ). In this case, a structure in which the first electrode sheet 11 , the second electrode sheet 12 , and the separator 13 are stacked is referred to as an electrode laminate 10 . In the electrode laminate 10 , the uncoated region 15 of the first electrode sheet 11 protrudes toward one side in the width direction of the electrode laminate 10 , and the uncoated region 15 of the second electrode sheet 12 is an electrode. It protrudes to the other side in the width direction of the laminated body 10 .

The first electrode sheet 11, the second electrode sheet 12, and the separator 13 are wound in a jelly roll type (S12). At this time, the electrode stack 10 is wound around a winding rod to form the electrode assembly 110 , and the winding rod is separated from the electrode assembly 110 . In the center of the electrode assembly 110 , a hollow core part 112 is formed at a portion where the winding rod is removed. The core part 112 is formed to pass through the axial direction of the electrode assembly 110 . The more the first electrode sheet 11 , the second electrode sheet 12 , and the separator 13 are stacked on the electrode stack 10 , the shorter the winding time and the manufacturing time of the electrode assembly 110 are.

The partial region C of the uncoated region shown in FIG. 1B may be removed after the electrode stack process ( S11 ) and before the winding process ( S12 ). This may be a process of cutting and removing a partial region of the uncoated region 15 by laser cutting.

The depth at which the uncoated region 15 is removed in the predetermined section C and the depth of the cutting line 113 may correspond to each other.

A recess portion 112a is formed between the uncoated portion 15 and the core portion 112 on one or both sides of the electrode cell body portion 111 in the axial direction. The recessed portion 112a is formed in an annular shape to surround the core portion 112 . The radial width W2 of the recess portion 112a may be the same as the height W1 of the uncoated portion 15 , or may be slightly wider or narrower (see FIGS. 9 and 10 ). The recessed portion 112a is formed to be concentric with the core portion 112 . The recessed portion 112a may be formed flush with or slightly lower than the cut surface portion 115 .

As the first cutter part 210 moves in the axial direction of the battery cell 100, the uncoated part 15 of the first electrode sheet 11 and the second electrode sheet 12 is cut in parallel in the radial direction (S13). ). At this time, the first cutter part 210 cuts the uncoated part 15 of the electrode cell body part 111 in the axial direction to separate the cutting scheduled part 115a and the bending scheduled part 117a. A pair of first cutting lines 113 parallel to the radial direction are formed between the cutting scheduled portion 115a and the bending scheduled portion 117a. At this time, the cutting scheduled portion 115a and the bending scheduled portion 117a maintain a standing state along the axial direction of the electrode cell body portion 111 as it is.

As the second cutter part 220 moves in the radial direction of the battery cell 100 , the second cutting line of the uncoated part 15 is cut to form the cut surface part 115 ( S14 ). The second cutter part 220 cuts the cut part 115a of the uncoated part 15 in the radial direction and removes it from the electrode cell body part 111 . Accordingly, in the uncoated portion 15 of the electrode cell body portion 111 , the bent portion 117a is disposed in a straight line with the radial direction. In addition, the cut surface portion 115 is formed in a semicircular shape on both sides of the bent portion (117a).

The pressing part 230 presses the bending part 117a of the uncoated part 15 to form the forming part 117 according to the laying down (S15). The forming part 117 is disposed between the cut surface parts 115 and is formed by pressing and laying down the bending part 117a of the uncoated part 15 . The forming part 117 may be formed by pressing the bending part 117a of the uncoated part 15 using a press part 230 to be described below and then laying it down. At this time, the plurality of non-cut pieces constituting the bending scheduled portion 117a may be continuously overlapped and laid down. Accordingly, the forming portion 117 may be formed to be slightly inclined in the axial direction of the electrode cell body portion 111 .

Since the cut surface part 115 is laser-welded to the current collecting plates 130 and 140 in a state of being in line contact with the current collecting plates 130 and 140 , the cut surface part 115 hardly increases the current path. On the other hand, since the forming portion 117 is formed by laying the bending portion 117a in a radial direction, the forming portion 117 covers the gap between the uncoated portions 15 spaced apart by the thickness of the separator 13 . Since the forming part 117 is welded in surface contact with the current collecting plates 130 and 140 , the current path between the electrode assembly 110 and the current collecting plates 130 and 140 is relatively increased as the area of the forming part 117 increases. can be Since the forming unit 117 increases the current path by an area that is the sum of the intervals between the uncoated regions 15 , even when applied to the large-capacity battery cell 100 , it is possible to suppress an increase in the amount of heat generated by the battery cell 100 and reduce the possibility of ignition. can

In the uncoated part 15 , after the part scheduled to be cut 115a and the part to be bent 117a are separated from each other, the part to be cut 115a is cut to form a cut surface part 115 , and the part to be bent 117a is pressed. to form the forming part 117 according to the laying down. Accordingly, when the forming portion 117 is formed by pressing the bending portion 117a, the boundary portion 16 between the forming portion 117 and the cut surface portion 115 is torn or irregularly distorted to prevent deformation. can

In addition, it is possible to prevent the edge of the separator 13 from being lifted or damaged by the torn or deformed portion of the boundary portion 16 . Accordingly, a short circuit between the first electrode sheet 11 and the second electrode sheet 12 can be prevented. Furthermore, it is possible to reduce the amount of heat generated by the battery cell 100 or significantly reduce the possibility of explosion.

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

The cut surface portion 115 has an inner end 115b on the side of the core 112 formed in a straight shape, and an outer end 115c formed in a circular arc shape. The inner end portion 115b forms a boundary line between the bent portion 117a and the cut surface portion 115 . The outer end 115c is disposed on the outer circumferential surface of the electrode cell body 111 .

The cut surface portion 117a has a central angle θ1 of 150° or more to less than 180° of the inner end of the core portion 112, and the outer end thereof is formed in an arc shape. In addition, the outer end of the cut surface portion 117a is formed in a circular arc shape. The inner end portion 115b forms a boundary line between the bent portion 117a and the cut surface portion 115 . The outer end 115c is disposed on the outer circumferential surface of the electrode cell body 111 .

In addition, the cut surface portion 117a may have a central angle θ1 of an inner end of the core portion 112 that is greater than 180° to less than 210°, and an outer end thereof may be formed in an arc shape.

In addition, the cut surface portion 117a may have an inner end of the core portion 112 rounded, and an outer end thereof may be formed in an arc shape.

The cut surface portion 115 may be formed by cutting the portion 16a spaced apart from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 by a predetermined distance (H: see FIG. 10 ) in the axial direction. . Accordingly, since the second cutter part 220 cuts the uncoated part 15 at a position spaced apart from the holding part 14 , it is possible to prevent the active material coated on the holding part 14 from being detached. In addition, even if the uncoated portion 15 is slightly deformed and cut, it is possible to prevent the holding portion 14 from being damaged or deformed.

The forming portion 117 may be formed in such a way that the bent portion 117a of the uncoated portion 15 is laid down toward the core portion 112 of the electrode cell body portion 111 . Accordingly, since the forming part 117 is prevented from protruding outward from the outer circumferential surface of the electrode cell body part 111 , the electrode assembly 110 smoothly enters the inside of the battery can 120 when the battery cell 100 is manufactured. can be put in In addition, it is possible to prevent the forming unit 117 from being caught in the battery can 120 .

The forming part 117 is formed by pressing and laying down the planned bending part 117a of the uncoated part 15 disposed between the pair of cut surface parts 115 in a direction crossing the axial direction, for example, in a radial direction. do. The forming part 117 may be formed by pressing the bending part 117a of the uncoated part 15 by using the press part 230 and laying it down. At this time, the forming unit 117 may be laid down while continuously overlapping a plurality of non-cut pieces constituting the planned bending unit 117a. Accordingly, the forming portion 117 may be formed to be inclined with respect to the axial direction of the electrode cell body portion 111 or to be completely flattened.

The width of the forming part 117 is formed to be the same. For example, when the front ends of the first blade 211 and the second blade 221 are formed in a straight line, the forming portion 117 may be formed to have the same width.

In addition, the forming part 117 may be formed to have a different width from the width of the core part 112 side. For example, when the central angle θ2 of the first blade 211 (see FIG. 7 ) and the tip of the second blade 221 are formed to be inclined, the forming unit 117 is formed between the width and the outer edge of the core unit 112 . different widths are formed.

The first cutter unit 210 cuts the uncoated area 15 while being vibrated by the first vibration generating unit 213 . The first vibration generator 213 may include an ultrasonic vibrator. Since the first cutter unit 210 cuts the uncoated area 15 while vibrating, the cutting performance and cutting speed of the uncoated area 15 may be improved.

The second cutter part 220 cuts the uncoated part 15 while being vibrated by the second vibration generator 223 . The second vibration generator 223 may include an ultrasonic vibrator. Since the second cutter unit 220 cuts the uncoated area 15 while vibrating, the cutting performance and cutting speed of the uncoated area 15 may be improved.

The above-described cutting of the cut surface portion 115 is preferably processed by the first cutter portion 210 first, and then processed by the second cutter portion 220 .

A battery cell manufactured using the electrode assembly as described above will be described.

15 is a cross-sectional view illustrating an electrode assembly according to the present invention.

Referring to FIG. 15 , the battery cell 100 according to the present invention includes an electrode assembly 110 , a battery can 120 , a sealing cap part 150 , and a first current collecting plate 130 .

Since the electrode assembly 110 is substantially the same as described above, a description thereof will be omitted.

The electrode assembly 110 is accommodated in the battery can 120 . The battery can 120 is electrically connected to any one of the first electrode sheet 11 and the second electrode sheet 12 to have a first polarity. The battery can 120 may be formed of a conductive material to allow current to flow. For example, the battery can 120 may be made of a material including a stainless material, an aluminum material, or the like. The battery can 120 may be formed in a cylindrical shape with an open end formed on one side (upper side in FIG. 15 ).

The sealing cap part 150 seals the open end of the battery can 120 . The sealing cap part 150 is installed to be insulated from the battery can 120 . The sealing cap 150 prevents foreign substances or moisture from penetrating into the battery can 120 .

The first current collecting plate 130 has a second polarity electrically connected to the other one of the first electrode sheet 11 and the second electrode sheet 12 . The first current collecting plate 130 may be disposed between the electrode assembly 110 and the sealing cap part 150 . The first current collecting plate 130 is electrically connected to the sealing cap part 150 . The first current collecting plate 130 may be welded to the uncoated region 15 of the other one of the first electrode sheet 11 and the second electrode sheet 12 . At this time, the forming part 117 of the uncoated region 15 is welded in a state of being in surface contact with the first current collecting plate 130 , and the cut surface 115 of the uncoated region 15 is connected to the first current collecting plate 130 . It can be welded in a pre-contact state. Accordingly, since the welding cross-sectional area of the uncoated region 15 and the first current collecting plate 130 is increased, the cross-sectional area of the current path is increased, thereby remarkably reducing the electrical resistance of the battery cell 100 . In addition, the amount of heat generated by the battery cell 100 may be reduced, and the possibility of ignition of the battery cell 100 may be reduced.

The first electrode sheet 11 may be a negative electrode sheet, and the second electrode sheet 12 may be a positive electrode sheet. In addition, the first electrode sheet 11 may be a positive electrode sheet, and the second electrode sheet 12 may be a negative electrode sheet.

An electrolyte is injected into the battery can 120 through the core part 112 of the electrode assembly 110 .

The electrolyte may be a salt having the same structure as A ⁺ B ^- . Here, A ⁺ includes an ion composed of an alkali metal cation such as Li ⁺ , Na ⁺ , K ⁺ or a combination thereof. And B ^- is F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , N(CN) ₂ ^- , BF ₄ ^- , ClO ₄ ^- , AlO ₄ ^- , AlCl ₄ ^- , PF ₆ ^- , SbF ₆ ^- , AsF ₆ ^- , BF ₂ C ₂ O ₄ ^- , BC ₄ O ₈ ^- , (CF ₃ ) ₂ PF ₄ ^- , (CF ₃ ) ₃ PF ₃ ^- , (CF ₃ ) ₄ PF ₂ ^- , (CF ₃ ) ) ₅ PF ^- , (CF ₃ ) ₆ P ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , CF ₃ CF ₂ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (FSO ₂ ) ₂ N ^- , CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- , (CF ₃ SO ₂ ) ₂ CH ^- , (SF ₅ ) ₃ C ^- , (CF ₃ SO ₂ ) ₃ C ^- , CF ₃ (CF ₂ ) ₇ SO ₃ ^- , CF ₃ CO ₂ ^- , CH ₃ CO ₂ ^- , SCN ^- and (CF ₃ CF ₂ SO ₂ ) ₂ N ^- contains any one or more anions selected from the group consisting of.

The electrolytic solution can also be used by dissolving it in an organic solvent. Examples of the organic solvent 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 (N- methyl-2-pyrrolidone, NMP), ethyl methyl carbonate (EMC), gamma butyrolactone (γ-butyrolactone), or a mixture thereof may be used.

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

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

The sealing cap part 150 includes a cap plate 151 installed to block the open end of the battery can 120 . The cap plate 151 may be formed in a circular plate shape as a whole. An external terminal 152 is formed in the center of the cap plate 151 to protrude outward (upper side in FIG. 13 ).

The sealing cap part 150 includes a vent plate 153 disposed below the cap plate 151 . The vent plate 153 is damaged when the internal pressure of the battery can 120 exceeds a preset pressure. The vent plate 153 prevents explosion of the battery cell 100 .

The vent plate 153 and the first current collecting plate 130 are electrically connected by a lead part 155 . In addition, the vent plate 153 is in contact with the cap plate 151 to form a part of the current path.

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

An insulator 157 is interposed between the inner surface of the supporter part 122 and the periphery of the vent plate 153 and the cap plate 151 . The insulator 157 covers the first current collecting plate 130 , and an edge is interposed between the inner peripheral surface of the supporter part 122 and the first current collecting plate 130 . This insulator 157 constitutes a part of the sealing cap part 150 .

A clamping part 123 is formed at the open end of the battery can 120 to press the cap plate 151 and the insulator 157 . The clamping part 123 bends the open end of the battery can 120 inward to seal the circumference of the cap plate 151 and the open end of the battery can 120 . Since the supporter part 122 fixes the clamping part 123 while pressing the circumferences of the first current collecting plate 130 and the vent plate 153 , the movement of the first current collecting plate 130 and the vent plate 153 is limited. As a result, assembly stability of the battery cell 100 may be improved. In addition, it is possible to prevent leakage of the airtightness of the battery can 120 due to an external impact.

Any one of the first electrode sheet 11 and the second electrode sheet 12 may be electrically connected to the battery can 120 via the second current collecting plate 140 . In this case, the second current collecting plate 140 may be welded to the uncoated region 15 formed on any one of the first electrode sheet 11 and the second electrode sheet 12 . The cut surface portion 115 of the uncoated area 15 and the forming portion 117 and the second current collecting plate 140 may be welded by a laser. Accordingly, since the welding cross-sectional area of the uncoated region 15 and the second current collecting plate 140 is increased, the cross-sectional area of the current path is increased, thereby remarkably reducing the electrical resistance of the battery cell 100 . In addition, the amount of heat generated by the battery cell 100 may be reduced, and the possibility of ignition of the battery cell 100 may be reduced.

In addition, it goes without saying that the uncoated area 15 formed on any one of the first electrode sheet 11 and the second electrode sheet 12 may be directly welded to the inner surface of the battery can 120 .

16 is a perspective view illustrating a state in which the electrode assembly according to the present invention is accommodated in the pack housing.

Referring to FIG. 16 , a battery pack according to an embodiment of the present invention includes an assembly to which cylindrical battery cells 100 are electrically connected and a pack housing 101 accommodating them. The cylindrical battery cell 100 may be any one of the battery cells 100 according to the above-described embodiment. In the drawings, parts such as a bus bar (not shown), a cooling unit (not shown), and an external terminal (not shown) for electrical connection of the cylindrical battery cells 100 are omitted for convenience of illustration.

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

17 is a view for explaining a vehicle including a battery pack according to the present invention.

Referring to FIG. 17 , a vehicle 300 according to an embodiment of the present invention includes a battery cell 100 according to an embodiment of the present invention. The vehicle is operated by receiving power from the battery cell 100 according to an embodiment of the present invention.

As described above, the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed in the present specification. It is obvious that variations can be made. In addition, although the effects according to the configuration of the present invention are not explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

10: electrode laminate
11: first electrode sheet
12: second electrode sheet
13: separator
14: maintenance part
15: Muzibu
16: border
16a: second cutting line
100: battery cell
101: pack housing
110: electrode assembly
111: electrode cell body part
112: core part
112a: recess
113: first cutting line
115: cut surface
115a: cut-off part
117: forming unit
117a: bending part
120: battery can
121: battery can body part
122: supporter part
123: clamping part
130: first current collecting plate
132: central hole
140: second current collecting plate
150: sealing cap part
151: cap plate
152: external terminal
153: bent plate
155: lead part
157: insulator
210: first cutter unit
211: first blade
213: first vibration generating unit
215: first communication hole part
220: second cutter unit
221: second blade
223: second vibration generating unit
230: press unit
300: vehicle

Claims (36)

The first electrode sheet 11 in the form of a sheet, the second electrode sheet 12 and the separator 13 are wound in a stacked state, and at least one of the first electrode sheet 11 and the second electrode sheet 12 is wound. A cutting device for cutting at least a portion of the uncoated area 15 of the electrode assembly 110 provided with the uncoated area 15 on which an active material layer is not coated at an end of one sheet in the width direction, the cutting device comprising:
A pair of first cutting lines 113 are cut in the axial direction while moving in the axial direction of the electrode assembly 110 to cut the uncoated region 15 extending in the axial direction so as to be parallel to the radial direction of the uncoated region 15 . ) forming a first cutter portion 210; and
A pair of second cutting lines 16a are formed in the circumferential direction on the uncoated region 15 wound in the circumferential direction while moving in the radial direction of the electrode assembly 110, and the pair of second cutting lines ( 116a) is respectively connected to the corresponding first cutting line 113, and the uncoated area surrounded by the first cutting line 113 and the second cutting line 116a is cut off, so that the uncoated area 15 is A cutting device comprising; According to claim 1,
The first cutter portion 210 includes a pair of first blades 211 disposed on both sides of the uncoated portion 15 in the radial direction and extending in the axial direction. According to claim 1,
The first cutter unit 210 further comprises a first vibration generating unit 213, the cutting device. According to claim 1,
The second cutter part 220 is formed in a rectangular shape with a blade formed at an end to cut the outside of the first cutting line 113 of the uncoated part 15 . According to claim 1,
The second cutter unit 220 further comprises a second vibration generating unit 223, cutting device. The cutting device of claim 1; and
As an electrode assembly processing apparatus including; a press part 230 for forming a forming part 117 by pressing and laying down a bending part 117a in which the uncoated part 15 is not cut,
The press part 230 is moved in the radial direction of the electrode cell body part 111 so that the bending scheduled part 117a between the pair of first cutting lines 113 of the uncoated part 15 is applied to the electrode cell. Laying down in the radial direction of the body portion 111, an electrode assembly processing apparatus. Laminating and winding the first electrode sheet 11, the second electrode sheet 12, and the separator 13 in the form of a sheet;
As the first cutter part 210 moves in the axial direction of the battery cell 100, the uncoated part 15 of the first electrode sheet 11 and the second electrode sheet 12 is cut in the axial direction to form a forming a pair of first cutting lines 113;
While the second cutter part 220 moves in the radial direction of the battery cell 100, a pair of second cutting lines 16a are formed in the uncoated part 15 wound in the circumferential direction in the circumferential direction, The uncoated portion surrounded by the first cutting line 113 and the second cutting line 16a is cut off so that the second cutting line 16a of the pair is connected to the corresponding first cutting line 113, respectively. forming a cut surface portion 115 on the outside of the pair of first cut lines 113 of the uncoated area 15 by making the first cut line 113; and
Forming the forming part 117 according to the pressing part 230 pressing the bending part 117a between the pair of first cutting lines 113 of the uncoated part 15 and laying it down in the radial direction. A method of manufacturing a battery cell 100 comprising a. 8. The method of claim 7,
The cutting surface portion 115 has an inner end 115b on the side of the core portion 112 formed in a straight shape, and an outer end portion 115c formed in an arc shape. 8. The method of claim 7,
The cut surface portion 115 has a central angle θ1 of 150° or more and less than 180° of the inner end portion 115b of the core portion 112 side, and the outer end portion 115c is formed in an arc shape, a battery cell The manufacturing method of (100). 8. The method of claim 7,
The forming part 117 is formed along the radial direction with the core part 112 as a center, the method of manufacturing the battery cell 100 . 8. The method of claim 7,
The forming part 117 has the same width as the manufacturing method of the battery cell 100 . 8. The method of claim 7,
The forming part 117 is formed to have a width different from a width on the side of the core part 112 and an outer width, the method of manufacturing the battery cell 100 . 8. The method of claim 7,
The forming part 117 is formed in a shape to be laid down toward the core part 112 from both outer sides of the forming part 117 , the method of manufacturing the battery cell 100 . 8. The method of claim 7,
The cut surface portion 115 is formed by cutting a portion spaced a predetermined distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 , the manufacturing method of the battery cell 100 . . 8. The method of claim 7,
The method of manufacturing the battery cell 100 , wherein the first cutter part 210 cuts the uncoated part 15 while being vibrated by the first vibration generator 213 . 8. The method of claim 7,
The method of manufacturing the battery cell 100 , wherein the second cutter part 220 is vibrated by a second vibration generator 223 to cut the uncoated part 15 . The first electrode sheet 11 in the form of a sheet, the second electrode sheet 12 and the separator 13 are laminated and wound in a jelly roll type, and the first electrode sheet 11 and the second electrode sheet 12 are stacked. an electrode cell body portion 111 in which an uncoated portion 15 on which an active material layer is not coated is formed at the end of at least one sheet in the width direction;
a pair of cut surface portions 115 formed by cutting out both sides of the uncoated portion 15 in the radial direction around the core portion 112 of the electrode cell body portion 111; and
A forming part 117 disposed between a pair of the cut surface parts 115 and formed by pressing and laying down the bending planned part 117a, which is a part in which the uncoated part 15 is not cut, comprising; electrode assembly 110 . 18. The method of claim 17,
In the cut surface portion 115 , the inner end 115b of the core portion 112 side is formed in a straight shape, and the outer end 115c is formed in an arc shape, the electrode assembly 110 . 18. The method of claim 17,
The cut surface portion 115 has a central angle θ1 of the inner end portion 115b on the side of the core portion 112 is formed to be 150° or more to less than 180°, and the outer end portion 115c is formed in an arc shape, the electrode assembly 110 . 18. The method of claim 17,
The forming part 117 is formed along the radial direction of the core part 112 , the electrode assembly 110 . 18. The method of claim 17,
The forming part 117 has the same width, the electrode assembly 110 . 18. The method of claim 17,
The forming part 117 is formed so that the width of the core part 112 side and the outer width are different from each other, the electrode assembly 110 . 18. The method of claim 17,
The forming part 117 is formed in a shape in which the bending part 117a is laid down in a radial direction of the electrode cell body part 111 , the electrode assembly 110 . 18. The method of claim 17,
The forming part 117 is formed in a shape to be laid down toward the core part 112 from both outer sides of the forming part 117 , the electrode assembly 110 . 18. The method of claim 17,
The cut surface portion 115 is formed by cutting a portion spaced a predetermined distance outward in the axial direction from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 . 18. The method of claim 17,
The core part 112 is formed in a hollow shape penetrating the center of the electrode cell body part 111 , the electrode assembly 110 . 18. The method of claim 17,
The electrode cell body portion 111 is formed in a cylindrical shape, the electrode assembly (110). 18. The method of claim 17,
The recess part is disposed on the core part 112 side of the uncoated part 15 of the electrode cell body part 111 and has a height recessed in the axial direction compared to the uncoated part 15 disposed radially outside it. The electrode assembly (110), further comprising (112a). 29. The method of claim 28,
In the uncoated part 15 of the electrode cell body part 111, it further includes a pair of cutting lines 113 provided in a radially outer portion than the recessed portion 112a and formed to a predetermined depth in the axial direction. , the electrode assembly 110 . 29. The method of claim 28,
The radial width of the recess portion 112a is the axial height of the bent portion 117a measured from the lower end of the cutting line 113 disposed adjacent to the recess portion 112a in the radial direction. and corresponding, the electrode assembly 110 . 29. The method of claim 28,
The cutting depth of the cutting line 113 is from the boundary portion 16 between the uncoated portion 15 and the holding portion 14 to a predetermined portion spaced apart by a predetermined distance outward in the axial direction, the electrode assembly 110 . 29. The method of claim 28,
The recess portion 112a has a height corresponding to the predetermined portion in the axial direction, the electrode assembly 110 . 33. The electrode assembly 110 of any one of claims 17 to 32;
a battery can 120 in which the electrode assembly 110 is accommodated and electrically connected to any one of the first electrode sheet 11 and the second electrode sheet 12 to have a first polarity;
a sealing cap 150 for sealing the open end of the battery can 120; and
A battery cell (100) including; a first current collecting plate (130) having a second polarity electrically connected to the other of the first electrode sheet (11) and the second electrode sheet (12). 34. The method of claim 33,
The insulator 157 interposed between the outer periphery of the sealing cap 150 and the inner periphery of the battery can 120 and interposed between the sealing cap 150 and the first current collecting plate 130; further comprising , battery cell 100 . A battery pack comprising at least one; the battery cell 100 according to claim 33. A vehicle comprising at least one; the battery pack according to claim 33.

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