Shock-resistant battery cell and manufacturing method thereof

Abstract

The present invention relates to a battery cell having excellent impact resistance and a method for manufacturing the same, and more particularly, to a battery cell having excellent impact resistance and a method for manufacturing the same, the battery cell comprising: a case having an accommodating space; an electrode assembly accommodated in the case, the electrode assembly including a negative electrode having a negative electrode tab, a positive electrode having a positive electrode tab, and a separator interposed between the negative electrode and the positive electrode; and a pair of electrode leads composed of a negative electrode lead electrically connected to the negative electrode tab and a positive electrode lead electrically connected to the positive electrode tab, in which at least one of the negative electrode tab and the positive electrode tab is provided with a plurality of holes spaced apart from each other by a predetermined distance in the length direction, so that even if a crack occurs in the electrode tab, the negative electrode tab and the positive electrode tab are separated from each other by a predetermined distance. And complete breakage of the electrode tab can be prevented.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0032267, filed on Mar. 13, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to an impact-resistant battery cell and a method for manufacturing the same, and more particularly, to an impact-resistant battery cell capable of preventing an electrode tab from being completely broken even if a crack occurs in the electrode tab and a method for manufacturing the same. Background Art

[0003] Recently, with the development of alternative energy sources due to air pollution and energy depletion caused by the use of fossil fuels, the demand for secondary batteries capable of storing generated electrical energy has increased. Secondary batteries capable of charging and discharging are closely used in daily life. For example, secondary batteries are used in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Due to the increase in the use of mobile devices, the increase in the complexity of mobile devices, and the development of electric vehicles, the required capacity of secondary batteries used as energy sources for various electronic devices that are inevitably used in modern society has increased. In order to meet the needs of users, a plurality of battery cells are provided in small devices, and a battery module including a plurality of battery cells electrically connected to each other or a battery pack including a plurality of battery modules is used in vehicles, etc.

[0005] Meanwhile, the shell of the soft-pack type battery cell is made of a flexible material such as a laminate sheet, and thus the shell of the soft-pack type battery cell may be more easily deformed than a cylindrical shell made of metal or a square shell made of metal. In other words, when an external force is applied to the soft-pack type battery cell, the shell is easily deformed, for example, bent, which may cause the electrode tab to be cut or the electrode tab and the electrode lead to be separated from each other at a junction therebetween.

[0006] In this regard, prior art documents disclose electrode stacks having multiple terminal tabs. Figure 1 As shown, Figure 1 2 is a plan view of a conventional electrode assembly, wherein a first terminal tab 22 of a plurality of first terminal tabs 22 and 24 is connected to a first lead terminal tab 26, and a first terminal tab 32 of a plurality of second terminal tabs 32 and 34 is connected to a second lead terminal tab 36. A second terminal tab 24 of a plurality of first terminal tabs 22 and 24 and a first lead terminal tab 26 are electrically connected to each other via a first electrode wire 2, and a second terminal tab 34 of a plurality of second terminal tabs 32 and 34 and a second lead terminal tab 36 are electrically connected to each other via a second electrode wire 3.

[0007] Although the electrode tab is composed of multiple tabs to disperse the stress caused by external force to some extent, the first electrode wire 2 and the second electrode wire 3 are required to respectively connect the second tab 24 with the first lead tab 26 and to connect the second tab 34 with the second lead tab 36, and the first electrode wire 2 and the second electrode wire 3 are prone to breakage.

[0008] In addition, a connection process of the first electrode wire 2 and the second electrode wire 3 must be performed, which leads to a new problem that the manufacturing time increases and it is necessary to check whether the electrode wires and the lead tabs are correctly connected to each other.

[0009] (Prior art literature)

[0010] (Patent Document 1) Korean Patent Application Publication No. 2017-0032031 (published on March 22, 2017) Summary of the invention

[0011] Technical issues

[0012] The present disclosure is made in view of the above problems, and an object of the present disclosure is to provide an impact-resistant battery cell capable of preventing breakage of an electrode tab even if cracks occur in the electrode tab due to an external force, and a method of manufacturing the same.

[0013] Technical Solution

[0014] In order to achieve the above-mentioned purpose, a battery cell according to the present disclosure comprises: a housing (100) having a housing space; an electrode assembly (200) housed in the housing (100), the electrode assembly comprising a negative electrode (210) having a negative electrode terminal tab (211), a positive electrode (220) having a positive electrode terminal tab (221), and a separator (230) interposed between the negative electrode (210) and the positive electrode (220); and a pair of electrode leads (300), the pair of electrode leads being composed of a negative electrode lead (310) electrically connected to the negative electrode terminal tab (211) and a positive electrode lead (320) electrically connected to the positive electrode terminal tab (221), wherein at least one of the negative electrode terminal tab (211) and the positive electrode terminal tab (221) is provided with a plurality of holes spaced apart from each other by a predetermined distance in a length direction.

[0015] Furthermore, in the battery cell according to the present disclosure, the shape of each hole may be polygonal, elliptical, or circular.

[0016] Furthermore, in the battery cell according to the present disclosure, a virtual line connecting the plurality of holes to one another may have at least one of a straight line shape, a mountain shape, a wavy shape, and a curved line shape.

[0017] In addition, in the battery cell according to the present invention, a plurality of holes may be formed in the negative electrode tab (211), and the plurality of holes may include a plurality of 1a holes (211a) spaced apart from each other by a predetermined distance in the length direction and a plurality of 1b holes (211b) spaced apart from each other by a predetermined distance in the length direction, and the 1a holes (211a) and the 1b holes (211b) are formed to be spaced apart from each other by a predetermined distance in the width direction.

[0018] Furthermore, in the battery cell according to the present invention, in the width direction of the negative electrode tab (211), the 1a hole (211a) may partially overlap with the 1b hole (211b), or may not overlap with the 1b hole (211b) at all.

[0019] In addition, in the battery cell according to the present invention, a plurality of holes may be formed in the positive electrode tab (221), the plurality of holes may include a plurality of 2a holes (221a) spaced apart from each other by a predetermined distance in the length direction and a plurality of 2b holes (221b) spaced apart from each other by a predetermined distance in the length direction, and the 2a holes (221a) and the 2b holes (221b) may be formed to be spaced apart from each other by a predetermined distance in the width direction.

[0020] Furthermore, in the battery cell according to the present invention, in the width direction of the positive electrode tab (221), the 2a hole (221a) may partially overlap with the 2b hole (221b) or may not overlap with the 2b hole (221b) at all.

[0021] In addition, in the battery cell according to the present invention, a plurality of holes may be formed in the negative electrode tab (211), and the plurality of holes may include a plurality of 1a holes (211a) spaced apart from each other by a predetermined distance in the length direction, a plurality of 1b holes (211b) spaced apart from each other by a predetermined distance in the length direction, and a plurality of 1c holes (211c) spaced apart from each other by a predetermined distance in the length direction, and the 1a holes (211a), 1b holes (211b) and 1c holes (211c) may be sequentially formed to be spaced apart from each other by a predetermined distance in the width direction.

[0022] In addition, in the battery cell according to the present invention, in the width direction of the negative electrode terminal tab (211), the 1b hole (211b) located in the middle may partially overlap with the 1a hole (211a) and the 1c hole (211c) located on the opposite side, or may not overlap with the 1a hole and the 1c hole at all.

[0023] In addition, in the battery cell according to the present invention, a plurality of holes may be formed in the positive electrode tab (221), and the plurality of holes may include a plurality of 2a holes (221a) spaced apart from each other by a predetermined distance in the length direction, a plurality of 2b holes (221b) spaced apart from each other by a predetermined distance in the length direction, and a plurality of 2c holes (221a) spaced apart from each other by a predetermined distance in the length direction, and the 2a holes (221a), 2b holes (221b) and 2c holes (221c) may be sequentially formed to be spaced apart from each other by a predetermined distance in the width direction.

[0024] In addition, in the battery cell according to the present invention, in the width direction of the positive electrode terminal tab (221), the 2b hole (221b) located in the middle may partially overlap with the 2a hole (221a) and the 2c hole (221c) located on the opposite side, or may not overlap with the 2a hole and the 2c hole at all.

[0025] In addition, the present invention provides a battery module including the battery cell.

[0026] In addition, the manufacturing method of a battery cell according to the present invention includes: a first step of preparing an electrode assembly configured so that a negative electrode having a negative electrode tab, a separator, and a positive electrode having a positive electrode tab are stacked in this order; a second step of connecting a negative electrode lead and a positive electrode lead to the negative electrode tab and the positive electrode tab, respectively; a third step of accommodating the electrode assembly with the electrode leads joined in a shell having a accommodating space; and a fourth step of sealing the edge of the shell, wherein, before the second step, the manufacturing method of the battery cell also includes forming a plurality of holes spaced apart from each other by a predetermined distance in a length direction in at least one of the negative electrode tab and the positive electrode tab.

[0027] In addition, in the manufacturing method of the battery cell according to the present invention, a plurality of holes are formed in the negative electrode tab (211), and the plurality of holes may include a plurality of 1a holes (211a) spaced apart from each other by a predetermined distance in the length direction and a plurality of 1b holes (211b) spaced apart from each other by a predetermined distance in the length direction, the 1a holes (211a) and the 1b holes (211b) are spaced apart from each other by a predetermined distance in the width direction, and in the width direction of the negative electrode tab (211), the 1a holes (211a) may partially overlap with the 1b holes (211b) or may not overlap with the 1b holes at all.

[0028] In addition, in the manufacturing method of the battery cell according to the present invention, a plurality of holes may be formed in the negative electrode tab (211), and the plurality of holes may include a plurality of 1a holes (211a) spaced apart from each other by a predetermined distance in the length direction, a plurality of 1b holes (211b) spaced apart from each other by a predetermined distance in the length direction, and a plurality of 1c holes (211c) spaced apart from each other by a predetermined distance in the length direction, and the 1a holes (211a), 1b holes (211b) and 1c holes (211c) may be sequentially formed to be spaced apart from each other by a predetermined distance in the width direction, and in the width direction of the negative electrode tab (211), the 1b hole (211b) located in the middle may partially overlap with the 1a holes (211a) and the 1c holes (211c) located on the opposite sides, or may not overlap with the 1a holes (211a) and the 1c holes (211c) at all.

[0029] Beneficial Effects

[0030] As is apparent from the above description, the impact-resistant battery cell and the method for manufacturing the same according to the present invention have the advantage that a plurality of holes spaced a predetermined distance apart from each other are formed in the electrode tab in the length direction thereof, whereby even if cracks occur, the propagation of the cracks can be stopped by the holes, thereby preventing the battery cell from being broken.

[0031] In addition, the impact-resistant battery cell and the method for manufacturing the same according to the present invention have the advantage that a plurality of holes spaced apart from each other by a predetermined distance are formed in the electrode tab not only in the length direction thereof but also in the width direction thereof, whereby the expansion of the crack is terminated by the holes regardless of the advancing direction of the crack, thereby preventing the battery cell from being broken. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a plan view of a conventional electrode assembly.

[0033] Figure 2 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention.

[0034] Figure 3 It is shown Figure 2 A plan view showing a state in which an electrode lead is connected to an electrode assembly.

[0035] Figure 4 It is along Figure 3 A cross-sectional view taken along line AA.

[0036] Figure 5 is a diagram illustrating the shape of a hole formed in an electrode tab according to a first preferred embodiment of the present invention.

[0037] Figure 6 is a diagram illustrating an arrangement of holes formed in an electrode tab according to a first preferred embodiment of the present invention.

[0038] Figure 7 is a plan view showing a state in which an electrode lead is connected to an electrode assembly according to a second preferred embodiment of the present invention.

[0039] Figure 8 is a plan view showing a state in which an electrode lead is connected to an electrode assembly according to a third preferred embodiment of the present invention.

[0040] Fig. 9 is a flowchart illustrating a method of manufacturing a battery cell according to a second preferred embodiment of the present invention. DETAILED DESCRIPTION

[0041] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, when describing the operating principle of the preferred embodiments of the present invention in detail, when the known functions and configurations incorporated herein may obscure the subject matter of the present invention, the detailed description thereof will be omitted.

[0042] In addition, in all drawings, the same reference numerals will be used to represent parts that perform similar functions or operations. Throughout the specification, when one part is connected to another part, not only can one part be directly connected to another part, but one part can be indirectly connected to another part via other parts. In addition, including a specific element does not mean excluding other elements, but means that these elements may also be included unless otherwise specified.

[0043] Hereinafter, an impact-resistant battery cell and a method of manufacturing the same according to the present invention will be described with reference to the accompanying drawings.

[0044] Figure 2 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention, Figure 3 It is shown Figure 2 A plan view showing a state in which the electrode lead is connected to the electrode assembly, and Figure 4 It is along Figure 3 A cross-sectional view taken along line AA.

[0045] like Figures 2 to 4 As shown, the battery cell according to the present invention includes a case 100 , an electrode assembly 200 , and an electrode lead 300 .

[0046] First, the case 100 may be composed of a lower case and an upper case, and a notch-shaped accommodation space configured to accommodate the electrode assembly 200 is formed in the case.

[0047] A receiving part is formed in the case 100 using a laminate sheet including an outer resin layer 110 , a metal layer 120 , and an inner resin layer 130 .

[0048] Specifically, the outer resin layer 110 located at the outermost side of the case 100 may be made of a heat-resistant resin exhibiting excellent tensile strength, moisture permeation resistance, and air permeation resistance to ensure heat resistance and chemical resistance while protecting the electrode assembly 200. As an example, the outer resin layer may be made of nylon or polyethylene terephthalate; however, the present invention is not limited thereto.

[0049] The metal layer 120 located between the outer resin layer 110 and the inner resin layer 130 corresponds to a barrier layer configured to prevent moisture or various gases from penetrating into the battery. A light-weight and easily moldable aluminum thin film may be used as a preferred material for the metal layer 120 .

[0050] The inner resin layer 130 located at the innermost side of the shell 100 is arranged to be in direct contact with the electrode assembly 200, so the inner resin layer must exhibit high insulation performance and high electrolysis resistance. In addition, the inner resin layer must exhibit high sealing properties to tightly isolate the shell from the outside, that is, the thermal bonding seal between the inner layers must exhibit excellent thermal bonding strength.

[0051] The inner resin layer 130 may be made of a material selected from polyolefin-based resins (e.g., polypropylene, polyethylene, polyethylene acrylic acid or polybutylene, polyurethane resin, and polyimide resin) exhibiting excellent chemical resistance and high sealing properties. However, the present invention is not limited thereto, and polypropylene exhibiting excellent mechanical properties (e.g., tensile strength, rigidity, surface hardness, and impact resistance) and excellent chemical resistance is most preferably used.

[0052] Despite Figure 2 3 and 4. It is shown that the accommodation space is provided in each of the upper case and the lower case, but the accommodation space may be provided in the upper case or the lower case.

[0053] Next, the electrode assembly 200 will be described. The electrode assembly 200 placed in the accommodation space of the case 100 may be a jelly roll type electrode assembly configured to have a long sheet-shaped negative electrode 210 and a long sheet-shaped positive electrode 220 wound in a state where a separator is interposed between the long sheet-shaped negative electrode 210 and the long sheet-shaped positive electrode 220, a laminated type electrode assembly configured to have a structure where a rectangular negative electrode 210 and a rectangular positive electrode 220 are stacked in a state where a separator is interposed between the rectangular negative electrode 210 and the rectangular positive electrode 220, a laminated folding type electrode assembly configured to have a structure where a unit cell is wound using a long separator, and a stacked laminated type electrode assembly configured to have a structure where unit cells are stacked in a state where a separator is interposed therebetween and then attached to each other; however, the present invention is not limited thereto.

[0054] Specifically, the negative electrode 210 is manufactured by applying a slurry mixture of a negative active material and a binder to a negative current collector.

[0055] As the negative electrode active material, for example, carbon (non-graphitizable carbon and graphite-based carbon); metal composite oxides such as Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1), Sn x Me1-xMe′ y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1 elements, Group 2 elements, Group 3 elements, halogens in the periodic table; 0<x≤1; 1≤y≤3; 1≤z≤8); lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4 or Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni based materials; or silicon-based materials such as Si, SiO, SiO2 or mixtures thereof. However, the present invention is not limited thereto.

[0056] The positive electrode 220 is manufactured by applying a slurry mixture of a positive active material and a binder to a positive current collector.

[0057] For example, the positive electrode active material may be composed of a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; 1+x Mn 2-x Lithium manganese oxide represented by LiMnO4 (wherein x is 0 to 0.33) or lithium manganese oxide such as LiMnO3, LiMn2O3 or LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxide such as LiV3O8, LiFe3O4, V2O5 or Cu2V2O7; a vanadium oxide represented by the chemical formula LiNi 1-x M x Nickel-oriented lithium nickel oxide represented by O2 (wherein M is Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x is 0.01 to 0.3); 2-x M xLithium manganese composite oxide represented by the chemical formula LiMnO2 (wherein M is Co, Ni, Fe, Cr, Zn or Ta, and x is 0.01 to 0.1) or LiMn2O4 (wherein M is Fe, Co, Ni, Cu or Zn); LiMn2O4, wherein a portion of Li in the chemical formula is replaced by alkaline earth metal ions; disulfide compounds; or Fe2(MoO4)3; however, the present invention is not limited thereto.

[0058] Meanwhile, each of the negative electrode collector and the positive electrode collector is composed of a coating portion coated with a slurry containing an active material and an uncoated portion not coated with the slurry. The uncoated portion is cut or a separate conductive member is connected to the uncoated portion by ultrasonic welding to form a pair of electrode tabs, namely, a negative electrode tab 211 and a positive electrode tab 221.

[0059] A thin insulating film having high particle permeability and mechanical strength is used as the separator 230 interposed between the negative electrode 210 and the positive electrode 220 or disposed outside the negative electrode 210. The pore size of the separator 230 is generally 0.01 μm to 10 μm, and the thickness of the separator is generally 5 μm to 300 μm. A sheet or non-woven fabric made of, for example, a chemically resistant and hydrophobic olefin-based polymer (e.g., polypropylene, glass fiber, or polyethylene) may be used as the separator 230; however, the present invention is not limited thereto.

[0060] A negative electrode lead 310 and a positive electrode lead 320 constituting a pair of electrode leads 300 are electrically connected to the negative electrode tab 211 and the positive electrode tab 221 , respectively, and are exposed to the outside of the case 100 .

[0061] Meanwhile, preferably, a plurality of holes spaced apart from each other by a predetermined distance in the length direction are formed in at least one of the negative electrode tab 211 and the positive electrode tab 221. Specifically, the negative electrode tab 211 may be provided with a plurality of 1a holes 211a spaced apart from each other by a predetermined distance in the length direction (i.e., along the Y axis), and the positive electrode tab 221 may also be provided with a plurality of 2a holes 221a spaced apart from each other by a predetermined distance in the length direction (i.e., along the Y axis).

[0062] As described above, when a plurality of holes spaced a predetermined distance apart from each other in the length direction are formed in the electrode tab, even if a crack occurs in the width direction (X-axis direction) of the electrode tab due to external stress, the expansion of the crack is terminated by the hole, thereby preventing the electrode tab from being completely broken.

[0063] Despite Figures 2 to 4 A bidirectional battery cell configured such that the negative electrode tab 211 and the positive electrode tab 221 are positioned facing each other is shown in FIG, but a unidirectional battery cell configured such that the electrode tabs are located in the same direction may also be used.

[0064] The overlapping portions between the respective electrode tabs constituting the negative electrode tab 211 and the positive electrode tab 221 and the electrode leads such as the negative electrode overlapping portion C1 and the positive electrode overlapping portion C2 are welded.

[0065] As an example, the electrode tab and the electrode lead may be electrically connected to each other by ultrasonic welding. The connection by ultrasonic welding may be performed according to a principle by which high-frequency vibration generated by ultrasonic waves of about 20 kHz is applied, and friction is generated at the interface between the electrode tab and the electrode lead as a result of the operation of the horn and the anvil, and the vibration energy is converted into heat energy, thereby rapidly performing welding. Of course, welding is not limited to ultrasonic welding, as long as the electrode tab and the electrode lead can be electrically connected to each other.

[0066] Although not shown in the drawings, the overlapping portion where the electrode tab and the electrode lead overlap each other, specifically, the overlapping portion where the electrode tab and the electrode lead are welded to each other, i.e., each of the negative electrode overlapping portion C1 and the positive electrode overlapping portion C2 may be provided with a protective tape (not shown) configured to cover the overlapping portion.

[0067] Since the electrode tab and the electrode lead are connected to each other by welding, the surface of the electrode tab and the surface of the electrode lead may not be smooth, which results in poor insulation.

[0068] In other words, if the surface of the overlapping portion is not smooth, when the overlapping portion and the soft package shell contact each other due to impact, the inner resin layer is peeled off and the metal layer is exposed, resulting in poor insulation. Therefore, it is preferred to use a protective tape to cover the overlapping portion to prevent poor insulation.

[0069] Here, the protective tape can be made of an insulating material, such as but not limited to polypropylene, polyethylene, polyester or polyimide. However, the material of the protective tape is not limited thereto, as long as the material can cover the weld and maintain insulation when in contact with the soft package shell.

[0070] In addition, although not shown in the figure, the lead film (not shown) is preferably provided at a position where the sealing portion of the soft pack shell and the electrode lead overlap each other. The reason for this is that the lead film can prevent the power generated from the electrode assembly from flowing into the soft pack shell via the electrode lead while maintaining the sealing of the soft pack shell.

[0071] The lead film is preferably made of a non-conductive material that does not conduct electricity well, and mainly uses an insulating tape that is easily attached to the electrode lead and is relatively thin; however, the present invention is not limited thereto.

[0072] Specifically, the lead film can be made of any one or more materials selected from the group consisting of polyimide (PI), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), high-density polyethylene (HDPE) and epoxy resin, and joined to the inner resin layer of the soft package shell by thermal welding using heat and pressure.

[0073] Figure 5 is a diagram showing the shape of a hole formed in an electrode tab according to a first preferred embodiment of the present invention, and Figure 6 is a diagram illustrating an arrangement of holes formed in an electrode tab according to a first preferred embodiment of the present invention.

[0074] Although the shape of the hole is not particularly limited, the shape of the hole may be at least one of a polygon including a quadrilateral, an ellipse, and a circle as long as the hole is formed on each of the negative electrode tab and the positive electrode tab in their length directions.

[0075] In addition, a virtual line connecting the holes provided at the electrode tabs to each other preferably has at least one of a straight line shape, a mountain shape, a wavy shape, and a curved line shape without being limited thereto.

[0076] Figure 7 is a plan view showing a state in which an electrode lead is connected to an electrode assembly according to a second preferred embodiment of the present invention. The second embodiment is identical in configuration to the first embodiment except for the arrangement of holes formed in the electrode tab.

[0077] In the second embodiment of the present invention, 1a holes 211 a and 1b holes 211 b are formed in the negative electrode tab 211 , and 2a holes 221 a and 2b holes 221 b are formed in the positive electrode tab 221 .

[0078] More specifically, the negative electrode tab 211 is provided with a plurality of 1a holes 211a spaced apart from each other by a predetermined distance in the length direction (Y-axis direction) and a plurality of 1b holes 211b spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), wherein the 1a holes 211a and the 1b holes 211b are formed to be spaced apart from each other by a predetermined distance in the width direction (X-axis direction).

[0079] In particular, in the width direction (X-axis direction) of the negative electrode tab 211 , the 1a hole 211a preferably partially overlaps with the 1b hole 211b , and more preferably does not overlap with the 1b hole at all.

[0080] When the holes are arranged at the negative electrode tab 211 so that the plurality of 1a holes 211a and the plurality of 1b holes 211b are spaced apart from each other by a predetermined distance in the width direction (X-axis direction), and part or all of the 1a holes 211a and the 1b holes 211b do not overlap with each other, as described above, the holes are formed on most of the electrode tab in the length direction (Y-axis direction), thereby more effectively preventing the electrode tab from being completely destroyed by cracks.

[0081] At the same time, the positive electrode tab 221 is provided with a plurality of 2a holes 221a spaced apart from each other by a predetermined distance in the length direction (Y-axis direction) and a plurality of 2b holes 221b spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), wherein the 2a holes 221a and the 2b holes 221b are formed to be spaced apart from each other by a predetermined distance in the width direction (X-axis direction).

[0082] In the same manner as the negative electrode tab 211, the 2a hole 221a preferably partially overlaps with the 2b hole 221b in the width direction (X-axis direction) of the positive electrode tab 221, and more preferably does not overlap with the 2b hole 221b at all. The reason is the same as that described for the negative electrode tab 211, so its repeated description will be omitted.

[0083] Figure 8 is a plan view showing a state in which an electrode lead is connected to an electrode assembly according to a third preferred embodiment of the present invention. The third embodiment is identical in configuration to the first embodiment except for the arrangement of holes formed in the electrode tab.

[0084] In the third embodiment of the present invention, 1a hole 211a, 1b hole 211b and 1c hole 211c are formed in the negative electrode tab 211, and 2a hole 221a, 2b hole 221b and 2c hole 212c are formed on the positive electrode tab 221.

[0085] More specifically, the negative electrode tab 211 is provided with a plurality of 1a holes 211a spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), a plurality of 1b holes 211b spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), and a plurality of 1c holes 211c spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), wherein the 1a holes 211a, the 1b holes 211b, and the 1c holes 211c are formed to be spaced apart from each other by a predetermined distance in the width direction (X-axis direction).

[0086] In particular, in the width direction (X-axis direction) of the negative electrode tab 211, the 1b hole 211b located in the middle preferably partially overlaps with the 1a hole 211a and the 1c hole 211c located on the opposite side, and more preferably, does not overlap with the 1a hole and the 1c hole at all.

[0087] When holes are formed in the negative electrode tab 211 to be arranged as described above, even if cracks occur obliquely in the length direction (Y-axis direction) and the width direction (X-axis direction) of the electrode tab, complete breakage of the electrode tab can be prevented.

[0088] Of course, the positive electrode tab 221 may also be provided with a plurality of 2a holes 221a spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), a plurality of 2b holes 221b spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), and a plurality of 2c holes 221c spaced apart from each other by a predetermined distance in the length direction (Y-axis direction), wherein the 2a holes 221a, the 2b holes 221b and the 2c holes 221c are formed to be spaced apart from each other by a predetermined distance in the width direction (X-axis direction).

[0089] In addition, in the same manner as the negative electrode tab 211, in the width direction (X-axis direction) of the positive electrode tab 221, the 2b hole 221b located in the middle preferably partially overlaps with the 2a hole 221a and the 2c hole 221c located on the opposite side, and more preferably, does not overlap with the 2a hole 221a and the 2c hole 221c at all. The reason is the same as the description of the negative electrode tab 211, so its repeated description will be omitted.

[0090] although Figure 8 It is shown that 1a holes 211a to 1c holes 211c are formed in the negative electrode tab 211, and 2a holes 221a to 2c holes 221c are formed in the positive electrode tab 221, but additional holes may be formed in the width direction (X-axis direction) of each electrode tab.

[0091] Fig. 9 : is a flowchart showing a method for manufacturing a battery cell according to a second preferred embodiment of the present invention. The method for manufacturing a battery cell according to the second embodiment of the present invention includes: a first step of preparing an electrode assembly configured such that a negative electrode having a negative electrode tab, a separator, and a positive electrode having a positive electrode tab are stacked in this order; a second step of connecting a negative electrode lead and a positive electrode lead to the negative electrode tab and the positive electrode tab, respectively; a third step of accommodating the electrode assembly joined with the electrode leads in a housing having an accommodation space; and a fourth step of sealing the edge of the housing.

[0092] Before the second step, more specifically, in the first step of preparing the electrode assembly, it is preferred that each of the negative electrode tab and the positive electrode tab disposed at the uncoated portion is punched or cut so that a plurality of holes spaced a predetermined distance apart from each other in the length direction are formed in the electrode tab.

[0093] The shape and arrangement of the holes are the same as those described above, so their repeated description will be omitted.

[0094] The present invention may provide a battery module or a battery pack including a battery cell.

[0095] Those skilled in the art to which the present invention pertains will appreciate that, based on the above description, various applications and modifications are possible within the scope of the present invention.

[0096] (Explanation of Reference Numerals)

[0097] 100: Soft case

[0098] 110: Inner resin layer

[0099] 120: Metal layer

[0100] 130: Outer resin layer

[0101] 200: Electrode assembly

[0102] 210: Negative electrode

[0103] 211: Negative terminal lug

[0104] 211a: 1a hole 211b: 1b hole

[0105] 211c: 1c hole

[0106] 220: Positive

[0107] 221: Positive terminal lug

[0108] 221a: 2a hole 221b: 2b hole

[0109] 221c: 2c hole

[0110] 230: Diaphragm

[0111] 300: Electrode lead

[0112] 310: Negative lead

[0113] 320: Positive lead

[0114] C1: Negative electrode overlap

[0115] C2: Positive electrode overlap

Claims

1. A battery cell, comprising: A housing having a receiving space; an electrode assembly accommodated in the housing, the electrode assembly comprising a negative electrode having a negative electrode terminal tab, a positive electrode having a positive electrode terminal tab, and a separator interposed between the negative electrode and the positive electrode; and a pair of electrode leads, the pair of electrode leads consisting of a negative electrode lead electrically connected to the negative electrode terminal tab and a positive electrode lead electrically connected to the positive electrode terminal tab, At least one of the negative electrode tab and the positive electrode tab is provided with a plurality of holes spaced apart from each other by a predetermined distance in a length direction.

2. The battery cell according to claim 1, wherein: The shape of each hole is polygonal, elliptical or circular.

3. The battery cell according to claim 1, wherein: A virtual line connecting the plurality of holes to each other has at least one of a straight line shape, a mountain shape, a wavy shape, and a curved shape.

4. The battery cell according to claim 3, wherein: The plurality of holes are formed in the negative electrode tab, The plurality of holes include a plurality of 1a holes spaced apart from each other by a predetermined distance in the length direction and a plurality of 1b holes spaced apart from each other by a predetermined distance in the length direction, and The 1a hole and the 1b hole are formed to be spaced apart from each other by a predetermined distance in a width direction.

5. The battery cell according to claim 4, wherein: In the width direction of the negative electrode tab, the 1a hole partially overlaps with the 1b hole or does not overlap with the 1b hole at all.

6. The battery cell according to claim 3, wherein: The plurality of holes are formed in the positive electrode tab, The plurality of holes include a plurality of 2a holes spaced apart from each other by a predetermined distance in the length direction and a plurality of 2b holes spaced apart from each other by a predetermined distance in the length direction, and The 2a hole and the 2b hole are formed to be spaced apart from each other by a predetermined distance in the width direction.

7. The battery cell according to claim 6, wherein: In the width direction of the positive electrode tab, the 2a hole partially overlaps with the 2b hole or does not overlap with the 2b hole at all.

8. The battery cell according to claim 3, wherein: The plurality of holes are formed in the negative electrode tab, The plurality of holes include a plurality of 1a holes spaced apart from each other by a predetermined distance in the length direction, a plurality of 1b holes spaced apart from each other by a predetermined distance in the length direction, and a plurality of 1c holes spaced apart from each other by a predetermined distance in the length direction, and The 1a hole, the 1b hole, and the 1c hole are sequentially formed to be spaced apart from each other by a predetermined distance in a width direction.

9. The battery cell according to claim 8, wherein: In the width direction of the negative electrode tab, the hole 1b located in the middle partially overlaps with the hole 1a and the hole 1c located on opposite sides, or does not overlap with the hole 1a and the hole 1c at all.

10. The battery cell according to claim 3, wherein: The plurality of holes are formed in the positive electrode tab, The plurality of holes include a plurality of 2a holes spaced apart from each other by a predetermined distance in the length direction, a plurality of 2b holes spaced apart from each other by a predetermined distance in the length direction, and a plurality of 2c holes spaced apart from each other by a predetermined distance in the length direction, and The 2a hole, the 2b hole, and the 2c hole are sequentially formed to be spaced apart from each other by a predetermined distance in the width direction.

11. The battery cell according to claim 10, wherein: In the width direction of the positive electrode tab, the 2b hole located in the middle partially overlaps with the 2a hole and the 2c hole located on opposite sides, or does not overlap with the 2a hole and the 2c hole at all. 12 . A battery module comprising the battery cell according to claim 1 .

13. A method for manufacturing a battery cell, comprising: A first step of preparing an electrode assembly configured such that a negative electrode having a negative electrode tab, a separator, and a positive electrode having a positive electrode tab are sequentially stacked; a second step of connecting a negative electrode lead and a positive electrode lead to the negative electrode tab and the positive electrode tab, respectively; a third step of accommodating the electrode assembly to which the electrode lead is joined in a housing having an accommodating space; and The fourth step of sealing the edge of the housing, Wherein, before the second step, the method for manufacturing the battery cell further includes a step of forming a plurality of holes spaced apart from each other by a predetermined distance in a length direction in at least one of the negative electrode tab and the positive electrode tab.

14. The method for manufacturing a battery cell according to claim 9, wherein: The plurality of holes are formed in the negative electrode tab, The plurality of holes include a plurality of 1a holes spaced apart from each other by a predetermined distance in the length direction and a plurality of 1b holes spaced apart from each other by a predetermined distance in the length direction, The 1a hole and the 1b hole are spaced apart from each other by a predetermined distance in the width direction, and In the width direction of the negative electrode tab, the 1a hole partially overlaps with the 1b hole or does not overlap with the 1b hole at all.

15. The method for manufacturing a battery cell according to claim 9, wherein: The plurality of holes are formed in the negative electrode tab, The plurality of holes include a plurality of 1a holes spaced apart from each other by a predetermined distance in the length direction, a plurality of 1b holes spaced apart from each other by a predetermined distance in the length direction, and a plurality of 1c holes spaced apart from each other by a predetermined distance in the length direction, The 1a hole, the 1b hole, and the 1c hole are sequentially formed to be spaced apart from each other by a predetermined distance in the width direction, and In the width direction of the negative electrode tab, the hole 1b located in the middle partially overlaps with the hole 1a and the hole 1c located on opposite sides, or does not overlap with the hole 1a and the hole 1c at all.

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