Highly impact-resistant battery cell and its manufacturing method

Abstract

The present invention relates to a battery cell having excellent impact resistance and a manufacturing method thereof. More specifically, the battery cell has excellent impact resistance, and includes: a pouch case having an accommodating space; an electrode assembly accommodated in the pouch 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 including a negative electrode lead electrically connected to the negative electrode tab and a positive electrode lead electrically connected to the positive electrode tab, wherein at least one of the negative electrode tab and the positive electrode tab has a plurality of holes formed therein at regular intervals along a longitudinal direction, thereby preventing complete disconnection even if a crack occurs in the electrode tab; and a manufacturing method thereof.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0032267, filed March 13, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a battery cell with excellent impact resistance and a manufacturing method thereof, and more particularly to a battery cell with excellent impact resistance that can prevent complete disconnection even if a crack occurs in an electrode tab, and a manufacturing method thereof. [Background technology]

[0003] Recently, due to air pollution and energy depletion caused by the use of fossil fuels, there has been an increasing demand for secondary batteries capable of storing electrical energy produced by the development of alternative energy sources. Rechargeable secondary batteries are closely used in everyday life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increasing use and complexity of mobile devices and the development of electric vehicles, etc. To meet user demands, small devices are equipped with multiple battery cells, while automobiles and the like use battery modules in which multiple battery cells are electrically connected or battery packs equipped with multiple such battery modules.

[0005] However, because pouch-type battery cell cases are made of flexible materials such as laminate sheets, they are more susceptible to deformation than cylindrical or rectangular cases made of metal. In other words, when an external force is applied to a pouch-type battery cell, the case is more susceptible to deformation, such as bending, which can result in the electrode tabs being cut or the connection between the electrode tabs and electrode leads being separated.

[0006] In this regard, a prior art document discloses an electrode stack structure having multiple tabs. As shown in Figure 1, which is a plan view of a conventional electrode assembly, the first tab 22 of the first multiple tabs 22, 24 is connected to the first lead tab 26, and the first tab 32 of the second multiple tabs 32, 34 is connected to the second lead tab 36. The second tab 24 of the first multiple tabs 22, 24 and the first lead tab 26 are electrically connected via a first electrode line 2, while the second tab 34 of the second multiple tabs 32, 34 and the second lead tab 36 are electrically connected via a second electrode line 3.

[0007] The electrode tabs are made up of multiple tabs, which disperses a certain portion of the stress caused by external force. However, the first electrode line 2 and the second electrode line 3 are required to connect the second tab 24 and the first lead tab 26, and the second tab 34 and the second lead tab 36, respectively, and these first electrode line 2 and second electrode line 3 are easily broken.

[0008] In addition, since a process of connecting the first electrode line 2 and the second electrode line 3 must be performed, not only does this extend the manufacturing time, but it also poses new problems, such as the need to inspect whether the electrode lines and lead tabs are properly connected. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2017-0032031 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to solve the above problems, an object of the present invention is to provide a battery cell having excellent impact resistance, which can prevent the electrode tab from being completely cut off even if a crack occurs in the electrode tab due to an external force, and a manufacturing method thereof. [Means for solving the problem]

[0011] To achieve the above object, the battery cell according to the present invention includes a case (100) having an accommodating space, an electrode assembly (200) accommodated in the case (100) and including an anode (210) having an anode tab (211), a cathode (220) having a cathode tab (221), and a separator (230) interposed between the anode (210) and the cathode (220), and a pair of electrode leads (300) consisting of an anode lead (310) electrically connected to the anode tab (211) and a cathode lead (320) electrically connected to the cathode tab (221), and at least one of the anode tab (211) and the cathode tab (221) has a plurality of holes formed therein at regular intervals along its length.

[0012] In the battery cell of the present invention, the holes may be polygonal, elliptical, or circular.

[0013] In the battery cell of the present invention, the imaginary line connecting the plurality of holes may have at least one of a linear shape, a mountain shape, a wave shape, and a curved shape.

[0014] In addition, in the battery cell of the present invention, the plurality of holes include a plurality of 1a holes (211a) formed in the negative electrode tab (211) and spaced apart at regular intervals along the longitudinal direction, and a plurality of 1b holes (211b) spaced apart at regular intervals along the longitudinal direction, and the 1a holes (211a) and 1b holes (211b) are formed to be spaced apart at regular intervals along the width direction.

[0015] In addition, in the battery cell of the present invention, when the width direction of the negative electrode tab (211) is taken as a reference, the 1a hole (211a) partially overlaps or does not completely overlap the 1b hole (211b).

[0016] In addition, in the battery cell of the present invention, the plurality of holes include a plurality of 2a holes (221a) formed in the positive electrode tab (221) and spaced apart at regular intervals along the longitudinal direction, and a plurality of 2b holes (221b) spaced apart at regular intervals along the longitudinal direction, and the 2a holes (221a) and the 2b holes (221b) are formed to be spaced apart at regular intervals along the width direction.

[0017] In addition, in the battery cell of the present invention, when the width direction of the positive electrode tab (221) is taken as a reference, the 2a hole (221a) partially overlaps or does not completely overlap the 2b hole (221b).

[0018] In addition, in the battery cell of the present invention, the plurality of holes are formed in the negative electrode tab (211) and include a plurality of 1a holes (211a) spaced apart at regular intervals along the length, a plurality of 1b holes (211b) spaced apart at regular intervals along the length, and a plurality of 1c holes (211c) spaced apart at regular intervals along the length, and the 1a holes (211a), 1b holes (211b) and 1c holes (211c) are sequentially formed to be spaced apart at regular intervals along the width.

[0019] In addition, in the battery cell of the present invention, when the width direction of the negative electrode tab (211) is taken as a reference, the 1b hole (211b) located in the center partially overlaps or does not completely overlap the 1a hole (211a) and the 1c hole (211c) on both sides.

[0020] In addition, in the battery cell of the present invention, the plurality of holes are formed in the positive electrode tab (221) and include a plurality of 2a holes (221a) spaced apart at regular intervals along the longitudinal direction, a plurality of 2b holes (221b) spaced apart at regular intervals along the longitudinal direction, and a plurality of 2c holes (221c) spaced apart at regular intervals along the longitudinal direction, and the 2a holes (221a), 2b holes (221b), and 2c holes (221c) are sequentially formed to be spaced apart at regular intervals along the width direction.

[0021] In addition, in the battery cell of the present invention, when the width direction of the positive electrode tab (221) is taken as a reference, the 2b hole (221b) located in the center partially overlaps the 2a hole (221a) and the 2c hole (221c) on both sides, or does not overlap at all.

[0022] The present invention is also characterized by a battery module including the above-described battery cell.

[0023] In addition, a method for manufacturing a battery cell according to the present invention includes: a first step of preparing an electrode assembly in which an anode with an anode tab, a separator, and a cathode with a cathode tab are stacked in this order; a second step of connecting an anode lead and a cathode lead to the anode tab and the cathode tab, respectively; a third step of accommodating the electrode assembly with the leads connected in a case having an accommodating space; and a fourth step of sealing an edge of the case, wherein the method further includes a step of forming a plurality of holes spaced at regular intervals along a longitudinal direction in at least one of the anode tab and the cathode tab prior to the second step.

[0024] In addition, in the method for manufacturing a battery cell according to the present invention, the plurality of holes include a plurality of 1a holes (211a) formed in the negative electrode tab (211) and spaced apart at regular intervals along the lengthwise direction, and a plurality of 1b holes (211b) spaced apart at regular intervals along the lengthwise direction, the 1a holes (211a) and the 1b holes (211b) are spaced apart at regular intervals along the widthwise direction, and the 1a holes (211a) partially overlap or do not completely overlap the 1b holes (211b) based on the widthwise direction of the negative electrode tab (211).

[0025] In addition, in the method for manufacturing a battery cell according to the present invention, the plurality of holes are formed in the negative electrode tab (211) and include a plurality of 1a holes (211a) spaced apart at regular intervals along the length, a plurality of 1b holes (211b) spaced apart at regular intervals along the length, and a plurality of 1c holes (211c) spaced apart at regular intervals along the length, and the 1a holes (211a), 1b holes (211b) and 1c holes (211c) are sequentially formed to be spaced apart at regular intervals along the width, and the 1b hole (211b) located in the center of the width of the negative electrode tab (211) partially overlaps or does not completely overlap with the 1a holes (211a) and 1c holes (211c) on both sides. [Effects of the Invention]

[0026] As described above, the impact-resistant battery cell and manufacturing method thereof according to the present invention has a structure in which a plurality of holes spaced at regular intervals are formed in the longitudinal direction of the electrode tab, thereby preventing breakage of the battery cell due to the structure in which even if a crack occurs, its propagation is stopped by the holes.

[0027] Furthermore, in accordance with the battery cell and manufacturing method thereof with excellent impact resistance according to the present invention, a plurality of holes spaced apart at regular intervals are formed not only in the longitudinal direction but also in the width direction of the electrode tab, which advantageously prevents breakage of the battery cell because crack propagation can be stopped by the holes regardless of the direction of crack propagation. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a plan view of an electrode assembly according to the prior art.

[0029] [Figure 2] 1 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention.

[0030] [Figure 3] 3 is a plan view of the electrode assembly shown in FIG. 2 in a state where an electrode lead is connected to the electrode assembly.

[0031] [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. 3.

[0032] [Figure 5] 4A and 4B are diagrams showing the shape of a hole formed in an electrode tab according to the first preferred embodiment of the present invention;

[0033] [Figure 6] 4A and 4B are diagrams showing the arrangement of holes formed in an electrode tab according to the first preferred embodiment of the present invention;

[0034] [Figure 7] 10 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. FIG.

[0035] [Figure 8] 10 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. FIG.

[0036] [Figure 9] 2 is a flowchart illustrating a method for manufacturing a battery cell according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person of ordinary skill in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0038] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0039] Hereinafter, a battery cell having excellent impact resistance and a method for manufacturing the same according to the present invention will be described with reference to the accompanying drawings.

[0040] FIG. 2 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention, FIG. 3 is a plan view of the electrode assembly shown in FIG. 2 with electrode leads connected thereto, and FIG. 4 is a cross-sectional view taken along line AA in FIG. 3.

[0041] As shown in FIGS. 2 to 4, the battery cell according to the present invention includes a case 100, an electrode assembly 200, and an electrode lead 300.

[0042] First, the case 100 is composed of a lower case and an upper case, and has a pocket-shaped receiving space formed therein to receive the electrode assembly 200 .

[0043] In such a case 100, the housing portion is formed using a laminate sheet made up of an outer resin layer 110, a metal layer 120, and an inner resin layer .

[0044] In particular, the outer resin layer 110 located at the outermost periphery of the case 100 may be made of a heat-resistant polymer having excellent tensile strength, moisture permeability, and air permeability so as to protect the electrode assembly 200 while ensuring heat resistance and chemical resistance. For example, nylon or polyethylene terephthalate may be used, but is not limited to these.

[0045] The metal layer 120 located between the outer resin layer 110 and the inner resin layer 130 corresponds to a barrier layer that prevents moisture and various gases from penetrating into the interior of the battery, and a suitable material for such metal layer 120 is an aluminum thin film, which is lightweight yet has excellent formability.

[0046] The inner resin layer 130, located at the innermost side of the case 100, is in direct contact with the electrode assembly 200 and must therefore have insulating and electrolytic resistance. Furthermore, the sealing properties required for sealing the case from the outside, i.e., the sealing portions where the inner layers are thermally bonded together, must have excellent thermal adhesive strength.

[0047] The material of the inner resin layer 130 may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and sealing properties, polyurethane resins, and polyimide resins, but is not limited thereto. Polypropylene is most preferred because of its excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact resistance, as well as chemical resistance.

[0048] For example, in FIG. 2, it is shown that the storage space is provided in both the upper case and the lower case. However, it is obvious that only one of the upper case or the lower case can have a storage space.

[0049] Next, the electrode assembly 200 will be described. The electrode assembly 200 seated in the storage space of the case 100 can be a jelly roll type electrode assembly having a structure in which a separator 230 is interposed between a long sheet-like negative electrode 210 and a positive electrode 220 and then wound, a stack type electrode assembly composed of unit cells having a structure in which a rectangular negative electrode 210 and a positive electrode 220 are laminated with the separator 230 interposed therebetween, a stack folding type electrode assembly in which the unit cells are wound by a long separation film, or a lamination stack type electrode assembly in which the unit cells are laminated with a separator interposed therebetween and adhered to each other, etc., but is not limited thereto.

[0050] Specifically, the negative electrode 210 is manufactured by applying a slurry in which a negative electrode active material, a binder, etc. are mixed to a negative electrode current collector.

[0051] Here, as the negative electrode active material, for example, carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me 1-x Me’ 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) and other metal composite oxides; 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, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials that are Si, SiO, SiO2 alone or mixtures thereof, etc. can be used, but are not limited to only these.

[0052] The positive electrode 220 is manufactured by applying a slurry containing a positive electrode active material and a binder to a positive electrode current collector.

[0053] Here, the positive electrode active material may be 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 such as LiMnO4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x Ni-site type lithium nickel oxide represented by MxO2 (where M=Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x=0.01 to 0.3); chemical formula LiMn 2-x M x Examples of the lithium manganese composite oxides include, but are not limited to, lithium manganese composite oxides expressed as LiMnO2 (where M is Co, Ni, Fe, Cr, Zn, or Ta, and x is 0.01 to 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the Li in the chemical formula is substituted with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0054] Meanwhile, the negative electrode current collector and the positive electrode current collector include a portion coated with a slurry containing an active material and a plain portion where the slurry is not coated. A pair of electrode tabs, i.e., a negative electrode tab 211 and a positive electrode tab 221, are formed by cutting the plain portion or by connecting a separate conductive member to the plain portion by ultrasonic welding or the like.

[0055] Furthermore, a separator 230, which is disposed between the positive electrode 210 and the negative electrode 220 or on the outside of the negative electrode 210, is an insulating thin film having high ion permeability and mechanical strength. The pore diameter of the separator 230 is generally 0.01 μm to 10 μm, and the thickness is generally 5 μm to 300 μm. The separator 230 may be made of, for example, a sheet or nonwoven fabric made of a chemically resistant and hydrophobic olefin polymer such as polypropylene, glass fiber, or polyethylene, but is not limited to these.

[0056] A pair of electrode leads 300 consisting of a negative electrode lead 310 and a positive electrode lead 320 are electrically connected to a negative electrode tab 211 and a positive electrode tab 221, respectively, and then exposed to the outside of the case 100.

[0057] Meanwhile, it is preferable that a plurality of holes spaced apart at regular intervals along the longitudinal direction be formed in at least one of the negative electrode tab 211 and the positive electrode tab 221. Specifically, it is preferable that a plurality of 1a holes 211a be formed in the negative electrode tab 211 at regular intervals along the Y axis, which is the longitudinal direction, and a plurality of 2a holes 221a be formed in the positive electrode tab 221 at regular intervals along the Y axis, which is the longitudinal direction.

[0058] When a plurality of holes spaced apart at regular intervals along the longitudinal direction are formed in the electrode tab as described above, even if a crack occurs in the width direction (X-axis direction) of the electrode tab due to external stress, the holes can stop the propagation of the crack, thereby preventing the electrode tab from being completely disconnected.

[0059] Although FIGS. 2 to 4 show a bidirectional battery cell in which the negative electrode tab 211 and the positive electrode tab 221 are positioned to face each other, the battery may be a unidirectional battery cell in which these tabs are positioned in the same direction.

[0060] Next, the electrode tabs and leads constituting the negative electrode tab 211 and the positive electrode tab 221 described above are welded at their overlapping portions, for example, the negative electrode overlapping portion C1 and the positive electrode overlapping portion C2.

[0061] For example, the electrode tab and the lead may be electrically connected by ultrasonic welding. Ultrasonic welding is achieved by applying high-frequency vibrations generated by ultrasonic waves of approximately 20 kHz to the interface between the electrode tab and the electrode lead, where vibration energy is converted into heat energy through friction as a horn and anvil are operated, resulting in rapid welding. Of course, any method may be used as long as it can electrically connect the electrode and the lead.

[0062] Although not shown in the drawings, the portions where the electrode tab and the electrode lead overlap, more specifically, the negative electrode overlapping portion C1 and the positive electrode overlapping portion C2, which are the portions where the electrode tab and the electrode lead are welded, may be provided with protective tape (not shown) to surround these overlapping portions.

[0063] Since the electrode tabs and electrode leads are connected by welding, the surfaces of the electrode tabs and electrode leads may become uneven, which may lead to poor insulation.

[0064] In other words, if the surface of the overlapping portion is not smooth and the overlapping portion comes into contact with the pouch case due to an impact or the like, the inner resin layer will peel off, exposing the metal layer, resulting in poor insulation. Therefore, to prevent the above-mentioned poor insulation, it is preferable to wrap the overlapping portion with protective tape.

[0065] Here, the protective tape is made of an insulating material, and may be selected from polypropylene, polyethylene, polyester, or polyimide materials, for example, but is not limited to these, as long as it is a material that can wrap the welded portion and maintain an insulating state when in contact with the pouch case.

[0066] Although not shown in the drawings, it is preferable to provide a lead film (not shown) at the position where the sealing portion of the pouch case and the electrode lead overlap, because this lead film can maintain the sealing of the case while preventing electricity generated in the electrode assembly from flowing to the case via the electrode lead.

[0067] The lead film 400 is preferably made of a non-conductive material that does not conduct electricity well, and is generally made of insulating tape that is easily attached to the electrode lead and has a relatively thin thickness, but is not limited to this.

[0068] Specifically, the lead film is made of 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 is thermally fused and bonded to the inner resin layer of the pouch case using heat and pressure.

[0069] FIG. 5 shows the shape of holes formed in an electrode tab according to a first preferred embodiment of the present invention, and FIG. 6 shows the arrangement of holes formed in an electrode tab according to the first preferred embodiment of the present invention.

[0070] As long as the holes can be formed along the longitudinal direction of the negative electrode tab and the positive electrode tab, the shape of the holes may be any one or more of a polygon including a square, an oval, and a circle, without being particularly limited thereto.

[0071] In addition, the imaginary line connecting the holes arranged in the electrode tab may have one or more shapes selected from the group consisting of a straight line, a mountain-like shape, a wave-like shape, and a curved line, but is not limited thereto.

[0072] 7 is a plan view of an electrode assembly according to a second preferred embodiment of the present invention, in which an electrode lead is connected. The only difference from the first embodiment is the arrangement of holes formed in the electrode tabs, and the remaining configuration is the same.

[0073] In the second embodiment of the present invention, the negative electrode tab 211 has the 1a hole 211a and the 1b hole 211b formed therein at the same time, and the positive electrode tab 221 has the 2a hole 221a and the 2b hole 221b formed therein at the same time.

[0074] More specifically, the negative electrode tab 211 is provided with a plurality of 1a holes 211a and a plurality of 1b holes 211b spaced apart at regular intervals along the longitudinal direction (Y-axis direction). The 1a holes 211a and the 1b holes 211b are spaced apart at regular intervals along the width direction (X-axis direction).

[0075] In particular, when the width direction (X-axis direction) of the negative electrode tab 211 is taken as the reference, it is preferable that the 1a-hole 211a partially overlaps the 1b-hole 211b, and more preferably that they do not overlap at all.

[0076] In this manner, when the holes 1a 211a and the holes 1b 211b are arranged in the negative electrode tab 211 so that the plurality of holes 1a 211a and the plurality of holes 1b 211b are spaced apart at regular intervals along the width direction (X-axis direction) and the holes 1a 211a and the holes 1b 211b do not overlap partially or completely, a structure is formed in which holes are formed over most of the electrode tab in the longitudinal direction (Y-axis direction), thereby more effectively preventing the electrode tab from being completely disconnected due to cracks.

[0077] Meanwhile, the positive electrode tab 221 is provided with a plurality of 2a holes 221a and a plurality of 2b holes 221b spaced apart at regular intervals along the longitudinal direction (Y-axis direction). The 2a holes 221a and the 2b holes 221b are spaced apart at regular intervals along the width direction (X-axis direction).

[0078] As with the negative electrode tab 211, when the width direction (X-axis direction) of the positive electrode tab 221 is taken as the reference, it is preferable that the 2a-hole 221a partially overlap with the 2b-hole 221b, and more preferably that they do not completely overlap. This is the same as what was explained for the negative electrode tab 211, so a repeated explanation will be omitted.

[0079] 8 is a plan view of an electrode assembly according to a third preferred embodiment of the present invention, in which an electrode lead is connected. The only difference from the first embodiment is the arrangement of holes formed in the electrode tabs, and the remaining configuration is the same.

[0080] In the third embodiment of the present invention, the negative electrode tab 211 has the 1a hole 211a, the 1b hole 211b, and the 1c hole 211c simultaneously formed therein, and the positive electrode tab 221 has the 2a hole 221a, the 2b hole 221b, and the 2c hole 221c simultaneously formed therein.

[0081] More specifically, the negative electrode tab 211 is provided with a plurality of 1a holes 211a, a plurality of 1b holes 211b, and a plurality of 1c holes 211c spaced apart at regular intervals along the longitudinal direction (Y-axis direction). The 1a holes 211a, 1b holes 211b, and 1c holes 211c are spaced apart at regular intervals along the width direction (X-axis direction).

[0082] In particular, when the width direction (X-axis direction) of the negative electrode tab 211 is taken as a reference, it is preferable that the 1b hole 211b located in the center partially overlaps with the 1a hole 211a and the 1c hole 211c on both sides, and it is more preferable that they do not overlap at all.

[0083] When holes are formed in the negative electrode tab 211 in the above-described arrangement structure, even if a crack occurs diagonally in the longitudinal direction (Y-axis direction) as well as in the width direction (X-axis direction) of the electrode tab, it is possible to prevent the electrode tab from being completely disconnected.

[0084] Of course, the positive electrode tab 221 may also be provided with a plurality of 2a holes 221a, a plurality of 2b holes 221b, and a plurality of 2c holes 221c spaced apart at regular intervals along the longitudinal direction (Y-axis direction). Here, the 2a holes 221a, the 2b holes 221b, and the 2c holes 221c are formed to be spaced apart at regular intervals along the width direction (X-axis direction).

[0085] Similarly to the negative electrode tab 211, when the width direction (X-axis direction) of the positive electrode tab 221 is taken as a reference, the centrally located hole 2b 221b preferably partially overlaps the hole 2a 221a and hole 2c 221c on both sides, and more preferably does not completely overlap them. This is the same as that described for the negative electrode tab 211, so a repeated description will be omitted.

[0086] In FIG. 8, the negative electrode tab 211 is shown as having holes 1a 211a to 1c 211c formed therein, and the positive electrode tab 221 is shown as having holes 2a 221a to 2c 212c formed therein, but it is clear that each tab may also have additional holes formed along the width direction (X-axis direction).

[0087] 9 is a flowchart illustrating a method for manufacturing a battery cell according to a preferred embodiment of the present invention. The method for manufacturing a battery cell according to the embodiment of the present invention includes the following steps: a first step of preparing an electrode assembly in which an anode with an anode tab, a separator, and a cathode with a cathode tab are stacked in this order; a second step of connecting an anode lead and a cathode lead to the anode tab and the cathode tab, respectively; a third step of accommodating the electrode assembly with the leads connected in a case having an accommodating space; and a fourth step of sealing the edges of the case.

[0088] Prior to the second step, more specifically, in the first step of preparing the electrode assembly, it is preferable to punch or cut the negative electrode tab and the positive electrode tab provided in the uncoated portion to form a plurality of holes spaced at regular intervals along the longitudinal direction.

[0089] The shape and arrangement of the holes are the same as those described above, so a duplicated explanation will be omitted.

[0090] The present invention may be a battery module or a battery pack including the above-described battery cells.

[0091] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0092] 100 cases 110 outer resin layer 120 metal layer 130 Internal resin layer 200 electrode assembly 210 negative electrode 211 Negative electrode tab 211a Hall 1a 211b Hall 1b 211c Hall 1c 220 Positive electrode 221 Positive electrode tab 221a Hall 2a 221b Hall 2b 221c Hall 2c 230 Separation membrane 300 electrode leads 310 Negative lead 320 Positive lead C1 Negative electrode overlapping part C2 Positive electrode overlapping part

Claims

1. a pouch case with a storage space; an electrode assembly housed in the pouch 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; a pair of electrode leads including a negative electrode lead electrically connected to the negative electrode tab and a positive electrode lead electrically connected to the positive electrode tab; At least one of the negative electrode tab and the positive electrode tab has a plurality of holes formed therein, the holes being spaced apart at regular intervals along a longitudinal direction of the battery cell.

2. The battery cell of claim 1 , wherein the hole has a polygonal, elliptical, or circular shape.

3. The battery cell of claim 1 , wherein the imaginary line connecting the plurality of holes has at least one of a linear shape, a mountain shape, a wave shape, and a curved shape.

4. 4. The battery cell of claim 1, wherein the plurality of holes include a plurality of 1a holes formed in the negative electrode tab and spaced apart at regular intervals along the length direction, and a plurality of 1b holes formed in the negative electrode tab and spaced apart at regular intervals along the length direction, the 1a holes and the 1b holes being spaced apart at regular intervals along the width direction.

5. The battery cell of claim 4 , wherein the first a hole partially overlaps or does not completely overlap the first b hole in the width direction of the negative electrode tab.

6. 4. The battery cell of claim 1, wherein the plurality of holes include a plurality of second a holes formed in the positive electrode tab and spaced apart at regular intervals along a longitudinal direction, and a plurality of second b holes formed in the positive electrode tab and spaced apart at regular intervals along a longitudinal direction, and the second a holes and the second b holes are spaced apart at regular intervals along a width direction.

7. The battery cell of claim 6 , wherein the second a-hole partially overlaps or does not completely overlap the second b-hole in the width direction of the positive electrode tab.

8. 4. The battery cell of claim 1, wherein the plurality of holes are formed in the negative electrode tab and include a plurality of 1a holes spaced apart at regular intervals along a longitudinal direction, a plurality of 1b holes spaced apart at regular intervals along a longitudinal direction, and a plurality of 1c holes spaced apart at regular intervals along a longitudinal direction, and the 1a holes, 1b holes, and 1c holes are sequentially formed to be spaced apart at regular intervals along a width direction.

9. 9. The battery cell of claim 8, wherein the 1b hole located at the center partially overlaps or does not completely overlap the 1a hole and the 1c hole on both sides in the width direction of the negative electrode tab.

10. 4. The battery cell of claim 1, wherein the plurality of holes are formed in the positive electrode tab and include a plurality of second a holes spaced apart at regular intervals along a longitudinal direction, a plurality of second b holes spaced apart at regular intervals along a longitudinal direction, and a plurality of second c holes spaced apart at regular intervals along a longitudinal direction, and the second a holes, the second b holes, and the second c holes are sequentially formed to be spaced apart at regular intervals along a width direction.

11. 11. The battery cell of claim 10, wherein the second hole b located at the center partially overlaps or does not completely overlap the second hole a and the second hole c on both sides in the width direction of the positive electrode tab.

12. A battery module comprising the battery cell according to claim 1.

13. A first step of preparing an electrode assembly in which 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 to which the lead is connected in a case having an accommodating space; a fourth step of sealing the edges of the case; The method for manufacturing a battery cell may further include, prior to the second step, forming a plurality of holes spaced apart at regular intervals along a longitudinal direction in at least one of the negative electrode tab and the positive electrode tab.

14. 14. The method of claim 13, wherein the plurality of holes include a plurality of 1a holes formed in the negative electrode tab and spaced apart at regular intervals along a longitudinal direction, and a plurality of 1b holes spaced apart at regular intervals along the longitudinal direction, the 1a holes and the 1b holes spaced apart at regular intervals along a width direction, and the 1a holes partially overlap or do not completely overlap the 1b holes in the width direction of the negative electrode tab.

15. 14. The method of claim 13, wherein the plurality of holes include a plurality of 1a holes formed in the negative electrode tab and spaced apart at regular intervals along a longitudinal direction, a plurality of 1b holes spaced apart at regular intervals along the longitudinal direction, and a plurality of 1c holes spaced apart at regular intervals along the longitudinal direction, the 1a holes, the 1b holes, and the 1c holes are sequentially formed to be spaced apart at regular intervals along a width direction, and the 1b hole located in the center of the width direction of the negative electrode tab partially overlaps or does not completely overlap the 1a holes and the 1c holes on both sides.

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