Electrode leads and correspondingly shaped lead input palettes

Abstract

The present invention relates to an electrode lead included in a pouch-type battery cell, and more specifically, to an electrode lead having an asymmetric shape so that a direction in which burrs, which inevitably occur on an electrode lead due to the characteristics of a metal plate cut by a press, are formed can be geometrically distinguished from a direction in which they are not. The present invention also provides a lead insertion pallet that can normally store an electrode lead having an asymmetric shape only in one direction, and is provided with an insertion port having a direction limiting part that interferes with the asymmetric shape and limits insertion when the electrode lead is stored in another direction. In short, the asymmetric shape makes it possible to distinguish between the top and bottom surfaces of the electrode lead, and the pallet allows the electrode lead to be stored and moved only in one of the top and bottom directions, so that the electrode lead is welded to an electrode tab in a pouch cell avoiding a portion where burrs are formed due to the press cutting process, thereby providing a pouch-type battery cell with improved stability by reducing misidentification caused by visually distinguishing between the top and bottom surfaces.

Description

[Technical field]

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0049893 filed on April 22, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a pressed electrode lead and a pallet for housing the same. [Background technology]

[0003] Secondary batteries, which have high applicability across a range of products and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical sources.

[0004] These secondary batteries not only have the primary advantage of dramatically reducing the use of fossil fuels, but also have the advantage of not producing any by-products from energy use, so they are attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

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

[0006] Meanwhile, secondary batteries are generally classified into cylindrical batteries and prismatic batteries in which an electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries in which an electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet, depending on the shape of the battery case. The electrode assembly housed in the battery case is a chargeable and dischargeable power generating element having a positive electrode, a negative electrode, and a separator structure interposed between the positive electrode and the negative electrode, and is classified into a jelly roll type in which a long sheet-like positive electrode and a negative electrode coated with an active material are wound up with a separator interposed between them, and a stack type in which a plurality of positive electrodes and negative electrodes of a predetermined size are stacked in sequence with a separator interposed between them.

[0007] Among these, the pouch-type battery cell is connected to the outside of the cell through electrode leads welded to electrode tabs connected to positive and negative electrodes of the battery cell, respectively.

[0008] 1 shows a cross section of one side of a typical pouch cell. Referring to this figure, the electrode tab 12 protrudes from an electrode assembly 11 in which negative and positive electrodes coated with active materials are stacked with a separator interposed therebetween, and is welded to the electrode lead 2 in contact with each other in the height direction, and a lead film 21 stacked in the width direction of the electrode lead 2 is thermally welded to the pouch, so that the electrode lead 2 protrudes and extends outside the pouch and the pouch is sealed. Ultrasonic welding is mainly used for the welding.

[0009] Meanwhile, the electrode lead 2 is generally produced by press-cutting a metal plate into a rectangular shape, and then attaching a lead film 21 thereto.

[0010] 2 to 4 respectively show the upper surface, the lower surface, and the side surface of the pressed electrode lead 2. Referring to these drawings, during this process, uneven burrs 23 are formed in the pressing direction, i.e., downward, on the edges of the electrode lead 2. These burrs 23 may cause problems in the ultrasonic welding process, and may result in poor welding between the electrode tab 12 and the electrode lead 2, and thus broken wires.

[0011] However, since the electrode lead generally has a symmetrical shape and the burrs are formed so minutely that they cannot be visually confirmed, in an actual welding process, the direction of the burrs must be confirmed by touch during the process of welding with the electrode tab to determine the insertion direction, which may lead to a problem of misidentification. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been devised against the background of the conventional technology described above, and aims to provide an electrode lead having an asymmetric shape so that an upper surface on which no burrs are formed due to the press processing can be distinguished from a lower surface on which burrs are formed.

[0013] Another technical object of the present invention is to provide a lead input pallet having a direction restricting portion so that the electrode leads having upper and lower surfaces are input in one direction during the press working.

[0014] Another technical object of the present invention is to prevent misidentification occurring in the process of distinguishing between upper and lower surfaces in a welding process between an electrode tab and an electrode lead by using the improved electrode lead and lead input pallet.

[0015] Another technical object of the present invention is to prevent breakage of the electrode tab portion by improving the bonding performance between the electrode tab and the electrode lead.

[0016] It is still another technical object of the present invention to provide an electrode lead having an improved structure, a pouch cell including the same, a battery pack including the pouch cell, and an electronic device including the battery pack.

[0017] The technical problem of the present invention is not limited to the above-mentioned object, and other objects and advantages of the present invention not mentioned can be understood from the following description and can be more clearly understood by the embodiments of the present invention. It will be understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as set forth in the claims. [Means for solving the problem]

[0018] In order to solve the above problems, the present invention provides an electrode lead having an asymmetric shape, and a lead insertion pallet having a direction restricting portion so that the electrode lead is inserted in one direction.

[0019] The means for solving these problems can be applied to an electrode lead, which is welded to an electrode tab in the manufacture of a pouch cell and serves to connect an electrode provided in an electrode assembly to which the electrode tab is connected, to the outside.

[0020] The electrode lead may be a metal plate and may be produced by press cutting, which may result in burrs being formed along an edge of one of the upper and lower surfaces of the electrode lead in the press cutting direction.

[0021] A lead film may be laminated on a part of the surface of the electrode lead, the lead film extending along the width direction of the electrode lead and protruding beyond the electrode lead in the width direction on both sides.

[0022] The edge of the electrode lead may be formed to have a predetermined asymmetric shape when viewed from the side where the burr is formed, and may have an inverted shape of the asymmetric shape when viewed from the side where the burr is not formed.

[0023] The asymmetric shape may be asymmetric with respect to an imaginary axis (X) passing through the centre of the electrode lead so as to be aligned with the length of the electrode lead.

[0024] The asymmetric shape may be asymmetric with respect to a virtual axis (Y) passing through the center of the electrode lead so as to be aligned in a width direction of the electrode lead.

[0025] The asymmetric shape may be point-asymmetric with respect to a center of the electrode lead.

[0026] The electrode lead may have the asymmetric shape simultaneously with the production of the electrode lead, that is, the electrode lead may be cut to have the asymmetric shape during the process of cutting by a press.

[0027] Alternatively, the asymmetric shape of the electrode lead can be formed by further processing after production of the electrode lead.

[0028] The asymmetric shape may include a chamfer at one corner.

[0029] The asymmetric shape may include an uneven shape provided at an edge portion.

[0030] One end of the electrode lead is a portion to be welded to the electrode tab, and the asymmetric shape may be formed by avoiding the welded portion, or may be formed at the other end of the welded portion in the length direction.

[0031] The asymmetric shape may be formed relative to the edge shape of the lead film.

[0032] An electrode lead according to one embodiment of the present invention may be cut into a pentagonal shape by pressing, with one corner of the rectangle being chamfered, and may include a lead film extending in the width direction, laminated on a portion of the surface of the electrode lead, and extending beyond the electrode lead on both sides in the width direction.

[0033] In this case, the chamfered shape may be formed at any corner of the other end in the length direction of the portion to be welded to the electrode tab, based on the lead film.

[0034] The electrode leads can be stored in a lead input pallet that stores them in a stacked manner.

[0035] The pallet may include an insertion port for receiving the electrode lead, and a direction restricting portion for restricting an insertion direction of the electrode lead.

[0036] The direction limiting portion may be shaped so that when the electrode lead is inserted in either the up or down direction, there is no interference with the shape of the edge of the electrode lead, but when the electrode lead is inserted in the other direction, there is interference with the shape of the edge of the electrode lead, restricting insertion or preventing it from being properly stored.

[0037] The pallet may be formed to accommodate an electrode lead having a lead film, and may further include a lead film accommodating opening for accommodating widthwise protruding portions of the lead film from the electrode lead.

[0038] The electrode lead may be inserted into the insertion port in a vertical direction or in a direction perpendicular thereto.

[0039] The port may accommodate one or more electrode leads.

[0040] A plurality of the above-mentioned input ports can be provided on one pallet.

[0041] A single pallet may have a plurality of inlets arranged side by side in the width direction and / or length direction.

[0042] The directional restraint may be of a shape that is complementary to or corresponds to the asymmetric shape of the electrode lead.

[0043] The direction limiting portion may be formed at a position corresponding to an asymmetric shape provided on the edge shape of the lead film.

[0044] A pallet according to an embodiment of the present invention may have an inlet, in which a plurality of electrode leads are stacked and stored, arranged in parallel in a plurality of rows and columns, for example, three rows and three columns, and the inlet may have a directional limiting portion having a shape corresponding to the electrode lead having a chamfered corner, and may be a pallet having a lead film storage inlet capable of storing a lead film.

[0045] Meanwhile, the present invention provides an improved electrode lead, a pouch-type secondary battery including the same, a battery pack including the pouch-type secondary battery, and an electronic device including the battery pack as a power source.

[0046] The electronic device may be selected from, for example, a computer, a mobile phone, a wearable electronic device, a power tool, an electric vehicle (EV), a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric motorcycle, an electric golf cart, or a power storage system.

[0047] The structure and manufacturing method of these electronic devices are well known in the art and will not be described in detail herein. Effect of the Invention

[0048] The present invention processes the electrode lead into an asymmetric shape, thereby making it possible to visually distinguish the upper and lower surfaces of the electrode lead. This makes it possible to prevent misidentification caused by distinguishing between a surface on which burrs are formed and a surface on which burrs are not formed by touch alone in conventional press processing. That is, when an electrode tab and an electrode lead are welded, the burrs may hinder the joining, which may result in poor welding and breakage. In order to prevent this, the present invention provides an improved electrode lead that can prevent the possibility of breakage by reliably distinguishing the upper and lower surfaces of the electrode lead.

[0049] From yet another viewpoint, the present invention can achieve the object without affecting the welding by forming the asymmetric shape so as to avoid the portion where the electrode lead is welded to the electrode tab.

[0050] From still another viewpoint, the present invention can achieve its object by forming the asymmetric shape in the lead film without affecting the shape of the metal portion of the electrode lead.

[0051] From yet another viewpoint, the present invention provides a lead input pallet having an input port into which the electrode leads having an asymmetric shape can be input and stored only in a certain direction. Thereby, until the electrode lead and the electrode tab are welded, the electrode leads can be stored by distinguishing between the surface on which the burr is formed and the surface on which the burr is not formed.

[0052] From still another viewpoint, the present invention can provide a lead input pallet in which a plurality of the input ports are arranged side by side in the width direction and / or the length direction.

[0053] In addition, the present invention can achieve various other effects, which will be described in each embodiment, or descriptions of effects that can be easily inferred by a person of ordinary skill in the art will be omitted. [Brief description of the drawings]

[0054] [Figure 1] 1 is a side cross-sectional view showing an electrode tab and an electrode lead welded together in a typical pouch cell. [Diagram 2] 4 is a plan view showing the upper surface of an electrode lead provided with a lead film. FIG. [Diagram 3] 11 is a plan view showing the lower surface of an electrode lead provided with a lead film and a portion where a burr is formed by press cutting. FIG. [Figure 4]1 is a side view showing a side surface of a typical rectangular electrode lead provided with a lead film, and a portion where a burr is formed by press cutting. [Diagram 5] FIG. 2 is a plan view showing the top surface of an electrode lead having a chamfered asymmetric shape. [Figure 6] FIG. 13 is a plan view showing one unit of a lead insertion port shaped to correspond to an electrode lead having an asymmetrical chamfered shape. [Figure 7] 1 is a plan view showing an electrode lead having an asymmetrical chamfered shape being appropriately accommodated in a single unit of a lead insertion port having a corresponding shape, without interference occurring. FIG. [Figure 8] 13 is a plan view showing a state in which an electrode lead having an asymmetrical chamfered shape is mistakenly placed in a unit of a lead insertion port having a corresponding shape, causing interference. FIG. [Figure 9] FIG. 2 is a plan view of a lead input pallet having multiple input openings arranged side by side, each of which has a shape corresponding to an asymmetrical chamfered electrode lead. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] The above-mentioned objects, features and advantages will be described in detail below with reference to the accompanying drawings, so that a person having ordinary skill in the art to which the present invention pertains can easily implement the technical idea of ​​the present invention. In describing the present invention, if a detailed description of a known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0056] Although the terms "first" and "second" are used to indicate various components, it is understood that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and it is understood that a first component may also be a second component unless otherwise specified.

[0057] In this specification, unless otherwise specified, each element may be singular or plural.

[0058] Hereinafter, when an arbitrary structure is arranged on the "top (or bottom)" of a component or "above (or below)" a component, it means that the arbitrary structure is not only arranged in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and the arbitrary structure arranged on (or below) the component.

[0059] In addition, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, but that there may be further components "intervening" between each component, or that each component may be "coupled," "coupled," or "connected" via further components.

[0060] As used herein, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprise" or "include" in this application should not be interpreted as including all of the multiple components or multiple steps described in the specification, and should be interpreted as including some components or some steps that may not be included or may further include additional components or steps.

[0061] In this specification, when it is expressed as "A and / or B", this means A, B or A and B, unless otherwise specified, and when it is expressed as "C to D", this means C or more and D or less, unless otherwise specified.

[0062] For ease of explanation, the directions of the long and short sides of the plane constituting the electrode lead in this specification are referred to as the length direction (X direction) and width direction (Y direction), respectively, and the direction perpendicular to the plane is referred to as the height direction (Z direction).

[0063] The present invention relates to an electrode lead that is included in a pouch-type secondary battery cell and is welded to an electrode tab.

[0064] A typical pouch cell 1 includes an electrode assembly 11, an electrode tab 12 connected to the electrode assembly 11, an electrode lead 2 connected to the electrode tab 12, a lead film 21 surrounding the electrode lead 2, and a pouch that contains the electrode assembly 11 and the electrode tab 12 and is welded and sealed on the lead film 21.

[0065] The electrode assembly 11 has a structure in which electrode plates (positive and negative electrode plates) coated with an active material on one or both sides are stacked with a separator interposed between them. The electrode tabs 12 may include a positive electrode tab connected to the positive electrode plate and a negative electrode tab connected to the negative electrode plate.

[0066] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be any active material known in the art.

[0067] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; 1+x Mn 2-x Lithium manganese oxides (LiMnO2), such as LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides, such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x M x Lithium nickel oxide with nickel site represented by the chemical formula LiMnO2 (wherein M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x=0.01 to 0.3); 2-x M xLithium intercalation materials include, but are not limited to, lithium manganese composite oxides represented by Li2Mn3MO8 (wherein M is Co, Ni, Fe, Cr, Zn, or Ta, and x is 0.01 to 0.1); LiMn2O4 in which part of the lithium in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, or composite oxides formed by a combination of these.

[0068] 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 does not cause a chemical change in the battery and has conductivity, and for example, stainless steel, aluminum, nickel, titanium, plastic carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. can be used. The electrode current collector can be formed with fine irregularities on its surface to increase the adhesive strength of the positive electrode active material, and can be in various forms such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0069] A conductive material can be further mixed into the positive electrode active material. These conductive materials are added in an amount of, for example, 1 to 50% by weight based on the total weight of the mixture containing the positive electrode active material. These conductive materials are not particularly limited as long as they do not cause chemical changes in the battery and have high conductivity, and examples of the conductive materials that can be used 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 thermal black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0070] The negative electrode is manufactured by applying and drying a negative electrode active material on a negative electrode current collector, and may further contain components such as the above-described conductive material, binder, solvent, etc. as necessary.

[0071] The negative electrode current collector has, for example, a thickness of 3 to 500 μm. These negative electrode current collectors are not particularly limited as long as they do not cause a chemical change in the battery and have conductivity. For example, copper, stainless steel, aluminum, nickel, titanium, plastic carbon, those surface-treated with carbon, nickel, titanium, silver, etc. on the surface of copper or stainless steel, aluminum-cadmium alloy, etc. can be used. Also, similar to the positive electrode current collector, fine irregularities can be formed on the surface to strengthen the binding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams, non-woven fabric bodies, etc.

[0072] The negative electrode active material is, for example, carbon such as graphitizable carbon, graphite-based carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8) metal composite oxides; lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials, etc. can be used.

[0073] The electrode tab 12 may be formed by a part of the electrode plate not coated with the active material protruding and extending outward from the laminated structure of the electrode plate and the separator. The parts extending from the plurality of laminated electrode plates can overlap each other to form the electrode tab 12.

[0074] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0075] FIG. 1 is a side cross-sectional view showing a state in which an electrode tab 12 and an electrode lead 2 are welded in a conventional pouch cell 1.

[0076] 1, the electrode tab 12 and the electrode lead 2 may both be made of an electrically conductive metal material. Thus, the electrode tab 12 and the electrode lead 2 may be electrically connected by stacking and overlapping end portions facing each other in the height direction such that a portion of the electrode tab 12 and the electrode lead 2 overlap in the length direction, and the overlapping portions are welded. The welding may be, for example, ultrasonic welding. However, the welding method is not limited thereto.

[0077] The electrode lead 2 can then protrude outside the pouch even after the insulated pouch is sealed via the lead film 21 to connect the battery cell to an electronic device or the like.

[0078] FIG. 2 is a plan view showing the top surface of a typical rectangular electrode lead 2 provided with the lead film 21, FIG. 3 is a plan view showing the bottom surface of the electrode lead 2 provided with the lead film 21 and a portion where burrs 23 are formed by press cutting, and FIG. 4 is a side view showing the side surface of the electrode lead 2 provided with the lead film 21 and a portion where burrs 23 are formed by press cutting.

[0079] 2 to 4, the electrode lead 2 may be a rectangular metal plate having a predetermined width in the width direction (Y), extending in the length direction (X), and having a length greater than its width. These electrode leads 2 are metal plates and can be manufactured by cutting the edges by pressing, and the shape of the edges thus cut may be rectangular. The length of the rectangle in the length direction may be greater than the length in the width direction.

[0080] A lead film 21 that further protrudes in the width direction is attached to the electrode lead 2. The pair of lead films 21 are welded to the upper and lower surfaces of the electrode lead 2, respectively, and both ends in the width direction may be welded to each other. This makes it possible to completely seal the gap between the lead film 21 and the electrode lead 2.

[0081] 3 and 4, during the pressing process, irregular burrs 23 may be formed on the electrode lead 2 along the cut surface of the edge toward the pressing direction. If the surface with these burrs 23 is welded in contact with the electrode tab 12 during welding between the electrode tab 12 and the electrode lead 2, problems such as poor welding and disconnection may occur. Therefore, the welding can be performed by bringing the surface of the electrode lead 2 without the burrs 23 into contact with the electrode tab.

[0082] In this regard, in order to make it possible to visually (geometrically) distinguish between the surface on which the burr 23 is formed and the surface on which the burr 23 is not formed, the embodiment provides an electrode lead 2 having an asymmetric shape 22 in the edge shape.

[0083] 5 is a plan view showing the upper surface of the electrode lead 2 having a chamfered asymmetric shape 22. Referring to this, the electrode lead 2 can include the asymmetric shape 22, which has a shape of an edge such that the upper and lower surfaces have different patterns when turned upside down, making it possible to visually identify which surface is facing up.

[0084] These asymmetric shapes 22 function in such a way that when the electrode lead 2 is stored in a pallet described below, if the electrode lead is inserted in the incorrect direction, it interferes with the specific shape of the pallet (directional restriction portion) and restricts insertion, but if the electrode lead is inserted in the correct direction, it does not interfere with the specific shape of the pallet (directional restriction portion) and allows insertion.

[0085] The asymmetric shape 22 may be a shape that is asymmetric with respect to a virtual axis (X) that is aligned with the length direction of the electrode lead 2 and passes through its center, and / or a shape that is asymmetric with respect to a virtual axis (Y) that is aligned with the width direction of the electrode lead 2 and passes through its center.

[0086] For example, when the electrode lead 2 is turned upside down with respect to the X-axis, the outline shape of the electrode lead 2 may be different when viewed from the same direction.

[0087] Furthermore, when the electrode lead 2 is turned upside down with respect to the Y-axis, the outline shape of the electrode lead 2 may be different when viewed from the same direction.

[0088] Preferably, the asymmetric shape 22 can be asymmetric with respect to either the X-axis or the Y-axis. The asymmetric shape 22 can be provided on the electrode lead 2 itself, excluding the lead film 21.

[0089] The asymmetric shape 22 may be formed simultaneously with the edge cutting process of the electrode lead 2. That is, the electrode lead 2 may be cut into a shape including the asymmetric shape 22 when the edge is first cut by pressing. In this case, there is an advantage that the burrs 23 generated in the edge cutting process may be in the same direction as the burrs generated in the press cutting process for forming the asymmetric shape 22.

[0090] In this case, there is an advantage that the shape of the edge of the electrode lead 2 when viewed from the direction in which the burrs 23 are formed and the shape of the edge of the electrode lead 2 when viewed from the direction in which the burrs 23 are not formed are not only different but are each determined to be a specific shape. That is, since the direction in which the burrs 23 are formed and the asymmetric shape 22 have a specific relationship with each other, the direction in which the burrs 23 are formed can be determined simply by checking the shape of the edge of the electrode lead 2.

[0091] However, even if the asymmetric shape 22 is not necessarily formed at the same time as the edge shape of the electrode lead 2, the above-mentioned effects can be obtained as long as the asymmetric shape 22 is formed in an automated process with the direction of the burrs caused by edge processing of the electrode lead 2 being determined.

[0092] The asymmetric shape 22 may be a chamfered shape provided at one corner of the rectangular electrode lead 2. The electrode lead 2 including the chamfered shape may be manufactured by cutting off one corner of an existing rectangular electrode lead 2, or may be manufactured by cutting a metal plate material into a pentagon including the chamfered shape from the beginning.

[0093] By chamfering one of the four corners of the electrode lead 2, an asymmetric shape in the X-axis and Y-axis directions can be realized without removing much of the material of the electrode lead 2. Also, cutting off a part of the corner portion has no or almost no effect on the process of welding the electrode lead 2 to a bus bar or the like.

[0094] The asymmetric shape can be created mainly by the cutting process of the electrode lead 2, but if these asymmetric shaped parts (cut parts) are present inside the pouch or in the sealing part of the pouch edge, the sharp corners of the cut parts may break the insulating layer on the inner surface of the pouch or it may be difficult to seal the pouch edge.

[0095] For this reason, the asymmetric shape can be designed to be located on the exterior of the pouch.

[0096] In another embodiment, the asymmetric shape 22 may be unevenly formed on an edge portion of the edge shape of the electrode lead 2. The unevenness may be uneven in the X-axis direction or uneven in the Y-axis direction.

[0097] The corner or edge portions having the asymmetric shape 22 can be provided at positions that are not between the welding point between the electrode tab and the electrode lead 2 (the welding point at one end of the electrode lead in the longitudinal direction) and the welding point between the electrode lead 2 and the bus bar (the welding point at the other end of the electrode lead in the longitudinal direction). This makes it possible to prevent the phenomenon of increasing the resistance of the electrode lead 2 having the asymmetric shape 22.

[0098] The asymmetric shape 22 may be formed to avoid one end of the electrode lead 2 overlapping and welded to the electrode tab 12. For example, the asymmetric shape 22 may be formed at the other end in the length direction of the end to be welded to the electrode lead 2. Thus, the asymmetric shape 22 may not affect the welding between the electrode lead 2 and the electrode tab 12.

[0099] On the other hand, the electrode lead 2 of the embodiment can be provided with a lead film 21 laminated on a part of its surface, extending in the width direction, and protruding further than the width of the electrode lead 2, and the asymmetric shape 22 is provided with respect to the shape of the edge of the lead film 21, so that the purpose can be achieved without affecting the shape of the metal part.

[0100] For example, the lead film 21 can be made asymmetrical with respect to the X-axis by chamfering the corners of the lead film 21 or by setting the distance by which the lead film 21 extends to one widthwise side from the electrode lead 2 to be different from the distance by which the lead film 21 extends to the other widthwise side. Of course, since the lead film 21 itself is disposed offset to one side in the lengthwise direction with respect to the electrode lead 2, the disposition of the lead film 21 with respect to the electrode lead 2 itself can embody asymmetry with respect to the Y-axis.

[0101] The electrode leads 2 including the asymmetric shape 22 may be input into a lead input pallet 3 and stored in a stacked manner. The lead input pallet 3 may include an input port 31 into which the electrode leads 2 are input, and the input port 31 may include a direction restricting portion 32 that restricts the electrode leads 2 from being input in only a certain direction.

[0102] Figure 6 is a plan view showing one unit of a lead insertion port 31 having a shape corresponding to an electrode lead 2 having a chamfered asymmetric shape 22, Figure 7 is a plan view showing an electrode lead 2 having a chamfered asymmetric shape 22 being properly stored in a unit of a lead insertion port 31 having a corresponding shape, so that no interference occurs, and Figure 8 is a plan view showing an electrode lead 2 having a chamfered asymmetric shape 22 being incorrectly stored in a unit of a lead insertion port 31 having a corresponding shape, so that interference occurs.

[0103] 6 to 8, when the electrode lead 2 is inserted in either the up or down direction (the correct direction), the direction limiting portion 32 is normally stored without interference, but when the electrode lead 2 is inserted in the other direction (the wrong direction), the direction limiting portion 32 may be shaped to interfere with the asymmetric shape 22 of the electrode lead 2 and limit insertion.

[0104] The direction limiting portion 32 may have a shape that is complementary to or corresponds to the asymmetric shape 22 of the electrode lead 2. For example, the direction limiting portion 32 may include a tapered shape that corresponds to the electrode lead 2 provided with the chamfered asymmetric shape 22. The shape of these direction limiting portions 32 is sufficient as long as it causes interference with the electrode lead 2 and prevents the electrode lead 2 from being inserted when the electrode lead 2 is inserted in a direction that does not face the asymmetric shape 22. For example, the shape of the direction limiting portion 32 may be various as long as it causes interference with a portion (other corner portion) where the asymmetric shape 22 is not provided when the electrode lead 2 is inserted upside down. In other words, the shape of the direction limiting portion is not necessarily limited to a tapered shape.

[0105] The electrode lead 2 can be inserted vertically into the insertion port 31. In other words, the electrode lead 2 can be inserted in the normal direction of the electrode lead 2.

[0106] 9 is a plan view of a lead input pallet 3 having a plurality of input ports 31 arranged side by side, each having a shape corresponding to an electrode lead 2 having a chamfered asymmetric shape 22. Referring to this figure, a plurality of input ports 31 may be arranged side by side in the length direction and / or width direction in one lead input pallet 3.

[0107] Moreover, the insertion port 31 may be open in the height direction so as to accommodate a plurality of electrode leads 2 in a stacked manner.

[0108] With further reference to Figures 6 to 8, the insertion opening 31 may include a lead film accommodating opening 33 that extends further in the width direction to accommodate the lead film 21 provided on the electrode lead 2, if the shape is such that it can accommodate the electrode lead 2.

[0109] When the asymmetric shape 22 of the electrode lead 2 is provided on the lead film 21, the direction limiting portion 32 can be formed in the lead film receiving opening 33 so as to correspond to this.

[0110] The electrode leads 2 having the asymmetric shape may be supplied to the lead input pallet 3 with the lead films 21 attached thereto. The electrode leads 2 supplied in this manner may be stored in a stacked form through a plurality of input ports 31 opened at the top of the lead input pallet 3.

[0111] The lead input pallet 3 containing the plurality of electrode leads 2 can be moved close to a welding device for the electrode tabs and electrode leads of the electrode assembly to provide the electrode leads 2 to the welding device. At this time, since the electrode leads 2 are correctly aligned, they can be welded to the electrode tabs in the direction in which they are supplied from the pallet 3.

[0112] It should be understood that the above-described embodiments are illustrative in all respects and are not limiting, and the scope of the present invention is indicated by the claims below rather than the above detailed description. Furthermore, it should be understood that the meaning and scope of the claims below, as well as all modifications and variations conceivable from the equivalent concepts, are included in the scope of the present invention.

[0113] As described above, the present invention has been described with reference to the illustrative drawings, but the present invention is not limited to the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. Even if the effects of the configuration of the present invention are not explicitly described and explained while describing the embodiments of the present invention, it is natural that the effects that can be predicted by the configuration should also be recognized. [Explanation of symbols]

[0114] 1 Pouch Cell 11 Electrode assembly 12 Electrode tab 2 Electrode Lead 21 Lead Film 22 Asymmetrical Shape 23 Bali 3 Lead input pallet 31 Inlet 32 Directional restriction section 33 Lead film storage port X length direction Y Width direction Z height direction

Claims

1. In a battery electrode lead that is press-formed to have a width direction and a length direction, Burrs are formed on either the upper or lower surface of the electrode lead due to press cutting, The outline of the electrode lead is When viewed from the surface on which the burr is formed, the burr is formed in a predetermined asymmetric shape, When viewed from a surface side on which the burr is not formed, the asymmetric shape is formed in an inverted shape. Electrode leads.

2. The electrode lead has an edge shape that is longer in the length direction than in the width direction. The electrode lead of claim 1 .

3. The asymmetric shape is asymmetric with respect to a virtual axis (X) passing through the center of the electrode lead so as to be aligned with the length direction. The electrode lead of claim 1 .

4. The asymmetric shape is a shape that is asymmetric with respect to a virtual axis (Y) passing through the center of the electrode lead so as to be aligned with the width direction. The electrode lead according to claim 3 .

5. The asymmetric shape is a shape that is asymmetric with respect to a virtual axis (Y) passing through the center of the electrode lead so as to be aligned with the width direction. The electrode lead of claim 1 .

6. The asymmetric shape includes a chamfer at one corner of the edge shape. The electrode lead of claim 1 .

7. The asymmetric shape includes a concave-convex shape provided at an edge portion of the edge shape. The electrode lead of claim 1 .

8. The electrode lead has one end in a longitudinal direction which is overlapped with and welded to the electrode tab, the asymmetric shape is formed at a position avoiding the one side end of the electrode lead to be welded to the electrode tab; The electrode lead of claim 1 .

9. The asymmetric shape is provided at the other end of the electrode lead in the longitudinal direction. The electrode lead of claim 8.

10. the electrode lead includes a lead film laminated on a surface of the electrode lead, extending along a width direction, and protruding further in the width direction than the electrode lead; The electrode lead of claim 1 .

11. The asymmetric shape is provided with respect to the edge shape of the lead film. The electrode lead of claim 10.

12. A lead input pallet for storing the electrode leads according to any one of claims 1 to 11 in a vertically stacked manner, An inlet into which the pressed electrode lead is inserted; and a direction limiting part that, when the electrode lead is inserted with its vertical direction aligned, does not interfere with the shape of the edge of the electrode lead, and, when the electrode lead is inserted with its vertical direction misaligned, causes interference and limits the insertion; Lead input pallet.

13. The direction limiting portion has a shape complementary to an asymmetric shape of the electrode lead.

13. The lead input pallet of claim 12.

14. The direction limiting portion has a shape corresponding to an asymmetric shape of the electrode lead.

13. The lead input pallet of claim 12.

15. The electrode leads are vertically input into the lead input pallet through the input port.

13. The lead input pallet of claim 12.

16. The input ports are provided in a plurality of juxtaposed positions in the width direction and the length direction of the electrode lead.

13. The lead input pallet of claim 12.

17. A lead input pallet for storing the electrode leads according to any one of claims 10 and 11 in a vertically stacked manner, an input port into which the pressed electrode lead is input; a lead film receiving opening capable of receiving a lead film provided along a width direction on a part of a surface of the electrode lead; and a direction limiting part that, when the electrode lead is inserted with its vertical direction aligned, does not interfere with the shape of the edge of the electrode lead, and, when the electrode lead is inserted with its vertical direction misaligned, causes interference and limits the insertion; Lead input pallet.

18. the direction limiting portion is formed at a position corresponding to an asymmetric shape of the lead film, 20. The lead input pallet of claim 17.

19. The input port is provided in a plurality of juxtaposed positions in the width direction and the length direction of the electrode lead.

20. The lead input pallet of claim 17.

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