Battery cell and battery module including same

Abstract

A battery cell according to one embodiment of the present invention includes an electrode assembly including a plurality of electrode plates stacked with a separator interposed therebetween; and a battery case in which the electrode assembly is mounted in a receiving section. The electrode assembly includes a plurality of electrode taps extending from the plurality of electrode plates, respectively. The plurality of electrode taps are arranged in a line with the same polarity to form an electrode tap array. At least one protective member is attached to ends of the plurality of electrode taps.

Description

[Technical field]

[0001] Cross-reference to related applications This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0157743 filed on November 23, 2020, and Korean Patent Application No. 10-2021-0143813 filed on October 26, 2021, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery cell and a battery module including the same, and more particularly to a battery cell with improved safety and a battery module including the same. [Background technology]

[0003] As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also as an energy source for power devices such as electric bicycles, electric cars, and hybrid electric cars.

[0004] Such secondary batteries are classified into cylindrical batteries and prismatic batteries in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet, according to the shape of the battery case. Here, the electrode assembly housed in the battery case is a power generating element capable of charging and discharging, which is composed of 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 separator is interposed between a long sheet-type positive electrode and a negative electrode coated with an active material and then wound up, and a stack type in which a plurality of positive electrodes and negative electrodes are stacked in sequence with a separator interposed between them.

[0005] Among these, the use of pouch-type batteries, which have a structure in which a stack-type or stack / folding-type electrode assembly is built into a pouch-type battery case made of an aluminum laminate sheet, is gradually increasing due to low manufacturing costs, small weight, easy modification, etc.

[0006] Fig. 1 is an exploded perspective view of a conventional battery cell, and Fig. 2 is an enlarged perspective view of an end of an electrode assembly included in the battery cell of Fig. 1.

[0007] 1 and 2, a conventional battery cell 10 includes an electrode assembly 30 consisting of a positive electrode 33, a negative electrode 34, and a separator 35 interposed therebetween, and an electrolyte inside a battery case 20. Here, the secondary battery 10 has a structure in which two electrode leads 40, 41 electrically connected to a positive electrode tab 31 and a negative electrode tab 32 of the electrode assembly 30 are sealed so as to be exposed to the other portions.

[0008] Here, in order to test the safety of a pouch-type battery cell such as the conventional battery cell 10, such as ignition or explosion during use, it is necessary to check whether a short circuit occurs and whether ignition occurs when an external force is applied to a battery in a buffered state, such as a collision or when a sharp metal foreign object penetrates the battery.

[0009] In this case, if a short circuit occurs at some electrodes in the battery cell 10, an overcurrent occurs in which a current flows from an electrode where no short circuit occurs to the electrode where the short circuit occurs through the welding surfaces of the electrode taps 31, 32. As a result, the electrode where the short circuit occurs heats up due to the overcurrent, and then reaches a thermal runaway state, resulting in a fire. In other words, there is a need to develop a battery cell that can ensure safety by suppressing the overcurrent caused by other electrodes even if a short circuit occurs at some electrodes in the battery cell. Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a battery cell and a battery module including the same, which have improved safety by suppressing overcurrent that may occur between multiple electrode plates in the battery cell.

[0011] The problems to be solved by the present invention are not limited to the problems mentioned above, and problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings. [Means for solving the problem]

[0012] According to one embodiment of the present invention, there is provided a battery cell comprising: an electrode assembly including a plurality of electrode plates stacked with a separator interposed therebetween; and a battery case in which the electrode assembly is mounted in a storage section. The electrode assembly comprises a plurality of electrode taps each extending from the plurality of electrode plates, the plurality of electrode taps being arranged in a line with the same polarity to form an electrode tap array, and at least one protective member is attached to an end of the plurality of electrode taps.

[0013] One of the at least one protective member may be joined to a portion of an end of the plurality of electrode taps, and another of the at least one protective member may be joined to a remaining portion of the end of the plurality of electrode taps.

[0014] The protective member may be joined to each end of the plurality of electrode taps.

[0015] The protective member will break when heat equal to or exceeds a first temperature is applied to the protective member.

[0016] The first temperature may be a temperature of resistive heat generated when a current equal to or greater than a first current flows through the electrode plate.

[0017] The first current may be a current of 10C or more.

[0018] The protective member may include a Pb--Sn (lead-tin) alloy.

[0019] The protective member may be formed from an alloy containing 30% to 45% by weight of lead (Pb) and 55% to 70% by weight of tin (Sn).

[0020] The battery may further include an electrode lead electrically connected to the electrode tap array and protruding toward an outside of the battery case.

[0021] An end of the electrode tap array may be in contact with the electrode lead.

[0022] An end of the protective member may be in contact with the electrode lead.

[0023] The battery case may include a sealing portion having an outer periphery sealed by heat sealing, and may include a lead film located at a portion corresponding to the sealing portion on at least one of an upper portion and a lower portion of the electrode lead.

[0024] The electrode lead may include a first electrode lead portion and a second electrode lead portion, the first electrode lead portion extending along an end of the electrode tap array, and the second electrode lead portion protruding from the first electrode lead portion toward an outside of the battery case.

[0025] The lead film can be disposed on the second electrode lead portion.

[0026] A method for manufacturing a battery cell according to one embodiment of the present invention includes a pre-welding step of joining protective members to electrode taps formed by extending from electrode plates; an electrode assembly manufacturing step of manufacturing an electrode assembly by interposing separators between a plurality of electrode plates to which the protective members are joined; and a welding step of stacking the electrode taps of the same polarity included in the electrode assembly to form an electrode tap array and contacting ends of the electrode tap array with electrode leads.

[0027] The method may further include a packaging step of mounting the electrode assembly electrically connected to the electrode lead in a receiving portion of a battery case.

[0028] A battery module according to another embodiment of the present invention may include the battery cells described above. Effect of the Invention

[0029] According to an embodiment, the present invention provides a battery cell including a plurality of electrode plates having protective members joined to the ends of electrode taps, and a battery module including the same, thereby suppressing overcurrent that may occur between the plurality of electrode plates in the battery cell and improving safety.

[0030] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is an exploded perspective view of a conventional battery cell. [Diagram 2] 2 is an enlarged perspective view of an end portion of an electrode assembly included in the battery cell of FIG. 1. [Diagram 3] FIG. 2 is an exploded perspective view of a battery cell according to the present embodiment. [Figure 4] 4 is an enlarged perspective view of an end portion of an electrode assembly included in the battery cell of FIG. 3. [Diagram 5] 4 is an enlarged perspective view of an end portion of an electrode plate included in the electrode assembly of FIG. 3. [Figure 6] 4 is an enlarged perspective view of an end portion of the electrode assembly of the battery cell of FIG. 3 when a short circuit phenomenon occurs in a part of the electrode assembly. [Figure 7] 4 is a flowchart showing a method for manufacturing a battery cell according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may, however, be embodied in various different forms and is not limited to the embodiments set forth herein.

[0033] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0034] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to the drawings. In the drawings, thicknesses are enlarged to clearly express various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0035] Additionally, throughout the specification, when a part is said to "comprise" a certain element, this means that it may further include other elements, but not excluding other elements, unless specifically stated to the contrary.

[0036] Additionally, throughout the specification, a "plan view" means a view of the subject part as seen from above, and a "sectional view" means a view of the subject part as seen from the side, taken along a vertical cut.

[0037] Fig. 3 is an exploded perspective view of a battery cell according to the present embodiment, and Fig. 4 is an enlarged perspective view of an end of an electrode assembly included in the battery cell of Fig. 3.

[0038] 3 and 4, the battery cell 100 according to the present embodiment includes an electrode assembly 300 including a plurality of electrode plates 330, 340 stacked with a separator (not shown) interposed therebetween, and a battery case 200 in which the electrode assembly 300 is mounted in a receiving portion 230. Here, the battery cell 100 may include an electrolyte together with the electrode assembly 300 inside the battery case 200. Here, two electrode leads 400, 410 electrically connected to a plurality of electrode taps 310, 320 extended from the plurality of electrode plates 330, 340 of the electrode assembly 300 may be formed in a sealed structure so as to be exposed to the other portion.

[0039] As an example, the battery case 200 may be a pouch-type battery case, and may be formed of a case body 210 including a recessed receiving portion 230 in which the electrode assembly 300 is seated and which can contain an electrolyte, and a cover 220 integrally connected to the case body 210. In addition, the battery case 200 may have an internal space sealed by fusion of the outer peripheries of the case body 210 and the cover 220. However, the embodiment of the present invention is not limited to the above structure, and may be replaced with a battery case of a secondary battery having a general structure.

[0040] For example, the electrolyte means an electrolyte in a liquid state, in which ions can move between the positive electrode and the negative electrode, and the secondary battery can be charged and discharged through ion exchange between the positive electrode and the negative electrode. The electrolyte used in the present invention includes, but is not limited to, organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, molten inorganic electrolytes, etc. that can be used in manufacturing lithium secondary batteries.

[0041] The following description will focus on the remaining components of the battery cell 100 excluding the battery case 200 .

[0042] 3 and 4, in the battery cell 100 according to the present embodiment, the electrode assembly 300 may be a stack-type electrode assembly or a stack / folding type electrode assembly. However, in FIG. 4, the illustration of a separator (not shown) included in the electrode assembly 300 is omitted, and in the battery cell 100 according to the present embodiment, a separator (not shown) may be interposed between the positive electrode plate 330 and the negative electrode plate 340 in the electrode assembly 300 depending on the shape of the electrode assembly 300.

[0043] In addition, the electrode assembly 300 includes a plurality of electrode taps 310, 320 formed by extending from the plurality of electrode plates 330, 340, respectively, and the electrode taps 310, 320 may be arranged on the same line with the same polarity to form an electrode tap array.

[0044] As an example, the electrode assembly 300 may have a positive electrode tap array in which a plurality of positive electrode taps 310 formed by extending from a plurality of positive electrode plates 330 are arranged in a row, and a negative electrode tap array in which a plurality of negative electrode taps 320 formed by extending from a plurality of negative electrode plates 340 are arranged in a row.

[0045] Figure 5 is an enlarged perspective view of an end of an electrode plate included in the electrode assembly of Figure 3. Figure 5(a) is an enlarged perspective view of an end of an electrode plate where a short circuit does not occur, and Figure 5(b) is an enlarged perspective view of an end of an electrode plate where a short circuit occurs.

[0046] 3 to 5(a), in the electrode assembly 300, each electrode plate 330, 340 is formed by extending an electrode tap 310, 320, and at least one protective member 315, 325 may be joined to an end of the electrode tap 310, 320.

[0047] More specifically, in the electrode assembly 300, one of the at least one protective members 315, 325 may be joined to a portion of the ends of the multiple electrode taps 310, 320, and another of the at least one protective members 315, 325 may be joined to the remaining portion of the ends of the multiple electrode taps 310, 320.

[0048] As an example, the electrode assembly 300 may include two protective members 315, 325, one of the two protective members 315, 325 may be joined to a portion of the ends of the electrode taps 310, 320, and the other of the two protective members 315, 325 may be joined to the remaining portion of the ends of the electrode taps 310, 320. However, this is not limited thereto, and the present embodiment also includes a case where two or more protective members 315, 325 are included and a case where a portion of the ends of the electrode taps 310, 320 is joined to each protective member 315, 325.

[0049] In the electrode assembly 300, protective members 315, 325 may be joined to the ends of the multiple electrode taps 310, 320, respectively.

[0050] 4, the electrode assembly 300 includes a plurality of protective members 315, 325, and the protective members 315, 325 are joined to ends of a plurality of electrode taps 310, 320, respectively. More specifically, in the electrode assembly 300, the electrode taps 310, 320 include electrode tap portions 311, 321 and protective members 315, 325, and ends of the electrode tap portions 311, 321 and the protective members 315, 325 may be joined to each other. More specifically, a first protective member 315 may be joined to ends of the positive electrode tap portion 311, and a second protective member 325 may be joined to ends of the negative electrode tap portion 321, respectively.

[0051] Referring to FIG. 5(b), the protective members 315 and 325 may be formed of a material that breaks when heat of a first temperature or more is applied. Here, the first temperature may be a temperature at which an abnormal phenomenon occurs, such as an overcurrent flowing due to a short circuit occurring in the electrode plates 330 and 340. More specifically, the first temperature may be a temperature of resistance heat that occurs when a current of a first current or more flows through the electrode plates 330 and 340. Here, the first current may be 10C (seal rate). That is, the protective members 315 and 325 break when a current of 10C or more flows through them. Also, the first temperature may be a temperature of 100 degrees Celsius or more. That is, the protective members 315 and 325 break when heat of a temperature of 100 degrees Celsius or more is transferred thereto.

[0052] As a result, when a current of 10C (seal rate) or more flows through some of the electrode plates 330, 340 and / or heat of 100 degrees Celsius or more is transferred, the protective members 315, 325 are broken. That is, even if a short circuit occurs in some of the electrode plates 330, 340, the protective members 315, 325 of the electrode plates 330, 340 where the short circuit occurs are broken, so that it is possible to restrict the movement of electrons between the electrode plates 330, 340 where the short circuit occurs and the electrode plates 330, 340 where the short circuit does not occur. That is, it is possible to prevent an overcurrent in the electrode plates 330, 340 where the short circuit occurs, and improve stability.

[0053] Here, when a current of less than 10C (seal rate) flows through some of the electrode plates 330, 340 and / or when heat of a temperature less than 100 degrees Celsius is transferred, the protective members 315, 325 will not break. This is because some of the electrode plates 330, 340 are simply in a heated state, and the amount of heat generated does not exceed the amount of heat released, so the battery cell 100 does not reach an ignition mode.

[0054] On the other hand, if the protective members 315, 325 are broken when a current of less than 10C (seal rate) flows and / or heat of less than 100 degrees Celsius is transferred, there is a problem that the current may be cut off even though the electrode plates 330, 340 are simply heated electrode plates that do not cause any abnormal phenomenon.

[0055] The protective members 315, 325 may be formed mainly of zinc, tin, or lead, or may be formed of an alloy mainly composed of these. As an example, the protective members 315, 325 may include a Pb-Sn (lead-tin) alloy. However, the protective members 315, 325 are not limited to the above-mentioned materials, and may also include components contained in a typical fuse.

[0056] When the protective members 315, 325 include a Pb-Sn (lead-tin) alloy, the protective members 315, 325 can be formed from an alloy containing 30% to 45% by weight of lead (Pb) and 55% to 70% by weight of tin (Sn). More specifically, the protective members 315, 325 can be formed from an alloy containing 33% to 43% by weight of lead (Pb) and 57% to 67% by weight of tin (Sn). As an example, the protective members 315, 325 can be formed from an alloy containing 35% to 40% by weight of lead (Pb) and 60% to 65% by weight of tin (Sn).

[0057] In this way, since the protective members 315, 325 contain a Pb-Sn (lead-tin) alloy in the ratio within the above range, the phase of the protective members 315, 325 can change from a solid to a liquid according to the heat temperature generated from the electrode plates 330, 340 where a short circuit has occurred. That is, the protective members 315, 325 of the electrode plates 330, 340 where a short circuit has occurred are cut due to the phase change of the protective members 315, 325, and the movement of electrons to the electrode plates 330, 340 where a short circuit has occurred can be restricted. That is, the overcurrent phenomenon of the electrode plates 330, 340 where a short circuit has occurred can be prevented, and stability can be improved.

[0058] 3 and 4, the battery cell 100 according to the present embodiment includes electrode leads 400, 410 that are electrically connected to the electrode tap array and protrude outward from the battery case 200. The battery case 200 also includes a sealing part 240 whose outer periphery is sealed by heat fusion, and a lead film 500 located in a portion corresponding to the sealing part 240 on at least one of the upper and lower parts of the electrode leads 400, 410.

[0059] More specifically, the positive electrode tap array formed by arranging a plurality of positive electrode taps 310 to each other may be electrically connected to the positive electrode lead 400, and the negative electrode tap array formed by arranging a plurality of negative electrode taps 320 to each other may be electrically connected to the negative electrode lead 410.

[0060] Here, ends of the electrode tap array may be joined to the electrode leads 400, 410. More specifically, the positive electrode tap array formed by arranging a plurality of positive electrode taps 310 may be joined to the positive electrode lead 400, and the negative electrode tap array formed by arranging a plurality of negative electrode taps 320 may be joined to the negative electrode lead 410. As an example, the ends of the electrode tap array and the electrode leads 400, 410 may be joined to each other by welding or heat fusion.

[0061] Also, at the ends of the electrode tap array, ends of the protective members 315, 325 joined to the electrode taps 310, 320 may be joined to the electrode leads 400, 410. More specifically, ends of the first protective member 315 joined to each end of the positive electrode taps 310 may be joined to the positive electrode lead 400, and ends of the second protective member 325 joined to each end of the negative electrode taps 320 may be joined to the negative electrode lead 410. As an example, the ends of the protective members 315, 325 and the electrode leads 400, 410 may be joined to each other by welding or heat fusion.

[0062] 3 and 4, in the battery cell 100 according to the present embodiment, the electrode leads 400, 410 may include a first electrode lead portion and a second electrode lead portion. Here, the first electrode lead portion may extend along an end of the electrode tap array in which the electrode taps 310, 320 are arranged, and the second electrode lead portion may protrude from the first electrode lead portion toward the outside of the battery case 200.

[0063] Here, an end of the electrode tap arrangement may be joined to the first electrode lead portion of the electrode leads 400, 410. More specifically, the positive electrode tap arrangement formed by arranging a plurality of positive electrode taps 310 may be joined to the first electrode lead portion of the positive electrode lead 400, and the negative electrode tap arrangement formed by arranging a plurality of negative electrode taps 320 may be joined to the first electrode lead portion of the negative electrode lead 410. As an example, the end of the electrode tap arrangement and the first electrode lead portions of the electrode leads 400, 410 may be joined to each other by welding or heat fusion.

[0064] Also, at the end of the electrode tap array, the ends of the protective members 315, 325 joined to the electrode taps 310, 320 may be joined to the electrode leads 400, 410. More specifically, the end of the first protective member 315 joined to each end of the positive electrode taps 310 may be joined to the first electrode lead portion of the positive electrode lead 400, and the end of the second protective member 325 joined to each end of the negative electrode taps 320 may be joined to the first electrode lead portion of the negative electrode lead 410. As an example, the ends of the protective members 315, 325 and the first electrode lead portions of the electrode leads 400, 410 may be joined to each other by welding or heat fusion.

[0065] Here, the lead film 500 may be disposed on the second electrode lead portion. More specifically, the lead film 500 may be disposed on a portion of the second electrode lead portion corresponding to the sealing portion 240.

[0066] FIG. 6 is an enlarged perspective view of an end portion of the electrode assembly of the battery cell of FIG. 3 when a short circuit occurs in a portion of the electrode assembly.

[0067] 3 to 6, in the battery cell 100 according to this embodiment, when a short circuit occurs in some of the electrode plates 330, 340, the protective members 315, 325 connected to the electrode taps 310, 320 of the corresponding electrode plates 330, 340 are broken. Here, when a short circuit does not occur in some of the electrode plates 330, 340, the protective members 315, 325 are maintained without being broken.

[0068] In this way, when the electrode plates 330, 340 have a short circuit, the protective members 315, 325 are cut, limiting the movement of electrons from the electrode plates 330, 340 where a short circuit does not occur, thereby preventing overcurrent and thermal runaway. In addition, the electrode plates 330, 340 where a short circuit does not occur can function as a battery normally, unlike the electrode plates 330, 340 where a short circuit has occurred, and a sudden shutdown of the device including the battery cell 100 can be prevented.

[0069] FIG. 7 is a flowchart showing a method for manufacturing a battery cell according to this embodiment.

[0070] Referring to FIG. 7, a method of manufacturing a battery cell according to an embodiment of the present invention includes a pre-welding step (S10); an electrode assembly manufacturing step (S20); and a welding step (S30).

[0071] 5 and 7, the pre-welding step (S10) may be a step of bonding protective members 315, 325 to ends of electrode tap portions 311, 321 formed by extending from each electrode plate 330, 340. As an example, the ends of the electrode tap portions 311, 321 and the protective members 315, 325 may be bonded to each other by welding or heat fusion.

[0072] 3, 4 and 7, in the electrode assembly manufacturing step (S230), a separator (not shown) may be interposed between a plurality of electrode plates 330, 340 to which protective members 315, 325 are bonded, to manufacture an electrode assembly 300. At this time, the electrode assembly 300 may be manufactured by a stack type or stack / folding type assembly method.

[0073] 3, 4 and 7, the welding step (S30) may be a step of forming an electrode tap array by stacking the electrode taps 310, 320 of the electrode assembly 300 with the same polarity, and joining the end of the electrode tap array to the electrode leads 400, 410. As an example, the end of the electrode tap array and the electrode leads 400, 410 may be joined to each other by welding or heat fusion. In this case, the end of the electrode tap array joined to the electrode leads 400, 410 may be the end of the protective member 315, 325.

[0074] Also, the method of manufacturing a battery cell according to the present embodiment may further include a packaging step (S40) of mounting the electrode assembly electrically connected to the electrode lead in a receiving portion of a battery case.

[0075] As a result, the battery cell manufacturing method according to the present embodiment manufactures the battery cell 100 including the plurality of electrode plates 330, 340 including the protective members 315, 325, thereby individually restricting the movement of electrons in the electrode plate in which a short circuit has occurred among the electrode plates 330, 340. That is, it is possible to prevent overcurrent and thermal runaway in the electrode plate in which a short circuit has occurred, thereby improving stability. In addition, the electrode plates 330, 340 in which a short circuit has not occurred can function as a battery normally, thereby preventing a sudden shutdown of the device including the battery cell 100.

[0076] A battery module according to another embodiment of the present invention includes the above-described battery cell. Meanwhile, one or more of the battery modules according to the present embodiment may be packaged in a pack case to form a battery pack.

[0077] The battery module and the battery pack including the battery module may be applied to various devices, such as vehicles including electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and may be applied to various devices that can use the battery module and the battery pack including the battery module, which also fall within the scope of the present invention.

[0078] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0079] 100: Battery cell 200: Battery case 300: Electrode assembly 311, 315: Protective materials 400, 410: Electrode lead 500: Lead film

Claims

1. An electrode assembly including a plurality of electrode plates stacked with a separator interposed therebetween; and The electrode assembly includes a battery case that is mounted in a receiving portion, The electrode assembly includes a plurality of electrode taps each extending from one of the plurality of electrode plates, The plurality of electrode taps are arranged on the same line so that the electrode taps have the same polarity to form an electrode tap array. a protective member is joined to each end of the plurality of electrode taps, The battery further includes an electrode lead electrically connected to the electrode tap array and protruding toward an outside of the battery case, the electrode lead includes a first electrode lead portion and a second electrode lead portion; the first electrode lead portion extends along an arrangement direction of the electrode tap array and is joined to ends of the protection member which are joined to ends of the electrode taps, respectively; the second electrode lead portion protrudes from the first electrode lead portion toward an outside of the battery case, The protective member is configured to separate an electrode tap of an electrode plate in which a short circuit has occurred from the first electrode lead portion.

2. one of the protective members is joined to a part of the ends of the plurality of electrode taps, The battery cell according to claim 1 , wherein another of the protective members is joined to remaining portions of the ends of the plurality of electrode taps.

3. The battery cell according to claim 1 or 2, wherein the protective member is broken when heat of a first temperature or higher is applied to the protective member.

4. The battery cell according to claim 3 , wherein the first temperature is a temperature of resistance heat generated when a current equal to or greater than a first current flows through the electrode plate.

5. The battery cell according to claim 4 , wherein the first current is a current of 10 C or more.

6. The battery cell according to claim 1 , wherein the protective member includes a Pb—Sn (lead-tin) alloy.

7. 7. The battery cell according to claim 6, wherein the protective member is made of an alloy containing 30% to 45% by weight of lead (Pb) and 55% to 70% by weight of tin (Sn).

8. The battery case includes a sealing part having an outer periphery sealed by heat sealing, The battery cell according to claim 1 , further comprising a lead film located in a portion of at least one of an upper portion and a lower portion of the electrode lead corresponding to the sealing portion.

9. The battery cell according to claim 8 , wherein the lead film is located at the second electrode lead portion.

10. a pre-welding step of joining protective members to electrode taps formed by extending from the electrode plates; a step of manufacturing an electrode assembly by interposing a separator between the plurality of electrode plates to which the protective member is bonded; and the electrode taps included in the electrode assembly are stacked on top of each other with the same polarity to form an electrode tap array, and a welding step is performed to bring an end of the electrode tap array into contact with an electrode lead, the electrode lead includes a first electrode lead portion and a second electrode lead portion; the first electrode lead portion extends along an arrangement direction of the electrode tap array and is joined to ends of the protection member that are joined to the electrode taps, respectively; the second electrode lead portion protrudes from the first electrode lead portion toward an outside of the battery case, the protective member is configured to separate an electrode tap of an electrode plate in which a short circuit has occurred from the first electrode lead portion.

11. The method of claim 10 , further comprising a packaging step of mounting the electrode assembly electrically connected to the electrode lead in a receiving portion of a battery case.

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

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