Title of Invention: Battery cell for evaluation of internal short circuit and method for evaluating internal short circuit of battery cell using same technical field [One] The present invention relates to a battery cell for evaluating an internal short circuit and a method for evaluating an internal short circuit of a battery cell using the same. [2] This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0169230 on December 17, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification. background [3] As the price of energy sources increases due to the depletion of fossil fuels and interest in environmental pollution is increasing, the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. In particular, as technology development and demand for mobile devices increase, demand for secondary batteries as an energy source is rapidly increasing. [4] In general, in a secondary battery, an electrode assembly is assembled with a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The assembled electrode assembly is mounted in a battery case, and an electrolyte is injected to prepare a battery cell. [5] Among secondary batteries, lithium secondary batteries are being used in various fields due to their excellent electrical characteristics. However, the lithium secondary battery has a problem in that safety is low. For example, a lithium secondary battery may ignite or explode in an abnormal operating state such as overcharge, overdischarge, exposure to high temperature, or electrical short circuit. Specifically, heat and gas are generated while an active material or electrolyte, which is a component of a battery cell, undergoes a decomposition reaction. The generated heat and gas increase the temperature and pressure inside the battery cell. The elevated temperature and pressure further accelerate the decomposition reaction, and eventually cause ignition or explosion. [6] Therefore, it is very important to secure the safety of the battery cell, and one of the methods is to evaluate the safety of the battery cell when an internal short circuit occurs. In particular, there is a need for an evaluation technique that simulates the occurrence of an internal short circuit of a battery cell. DETAILED DESCRIPTION OF THE INVENTION technical challenge [7] The present invention was devised to solve the above problems, and provides a battery cell for evaluating an internal short circuit that can easily induce an internal short circuit of the battery cell, and a method for evaluating an internal short circuit of a battery cell using the same. means of solving the problem [8] The present invention provides a battery cell for evaluating the internal short circuit of the battery cell. In one example, the battery cell for evaluation of internal short circuit according to the present invention, [9] A holding part region in which a first electrode mixture layer is applied to one or both surfaces of a metal current collector, and a first electrode tab formed to protrude in one direction from the holding part region, but to which the first electrode mixture layer is not applied; a first electrode in which an uncoated region to which the first electrode mixture layer is not applied is formed in some of the sub-regions; [10] a first sub separator that covers the uncoated area of ​​the first electrode and has a larger area than the uncoated area; [11] a first shorting electrode formed at a position equal to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the first electrode; [12] a main separator interposed between both electrodes to cover the holding portion regions of the first and second electrodes; [13] a second shorting electrode formed at a position equivalent to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the second electrode; [14] a second sub separator that covers the uncoated area of ​​the second electrode and has a larger area than the uncoated area; and [15] A holding part region in which a second electrode mixture layer is applied on one or both surfaces of a metal current collector, and a second electrode tab formed to protrude in one direction from the holding part region, but to which the second electrode mixture layer is not applied; The second electrode in which the uncoated region to which the second electrode mixture layer is not applied is formed in some of the sub-regions. [16] includes [17] In a specific example, the first and second shorting electrodes each have a structure formed of a porous metal foil. [18] In another specific example, each of the first and second shorted electrodes has a structure formed of a porous metal foil having a porosity of 50% (v/v) or more. [19] In one example, in the battery cell for evaluating an internal short circuit, the first sub separator has a structure formed by extending in a direction opposite to the direction in which the first shorting electrode protrudes from the holding part region of the first electrode, and the second sub separator includes It has a structure in which the second shorting electrode extends in a direction opposite to the direction in which it protrudes from the holding portion region of the second electrode. [20] In another example, in the first and second electrodes, the first and second electrode tabs each independently have a structure protruding in one direction or in a direction opposite to the one direction in the holding part region, and in the first and second paragraphs The electrode has a structure in which the first and second electrode tabs protrude in another direction perpendicular to the protruding direction, and the first and second sub separators extend in opposite directions to the protruding direction of the first and second shorting electrodes. the structure formed. [21] In one example, the battery cell includes an electrode assembly having a structure in which a unit stack in which a first electrode, a main separator, and a second electrode are sequentially formed is repeated, and at least one of the unit stacks includes a first electrode; a first sub-separation membrane; a first shorting electrode; main separator; a second shorting electrode; a second sub-separation membrane; and a structure in which the second electrode is sequentially formed. [22] In a specific example, the battery cell for evaluation of internal short circuit according to the present invention further includes a main separator interposed between the unit stack and the unit stack. [23] In a specific example, the first and second sub-separators are a fabric separation membrane structure formed of a porous fabric made of a film material, and the main separator is a safety-reinforced separator structure in which inorganic particles are dispersed and coated on one or both surfaces of the fabric separator. [24] In one example, the metal current collector of the first electrode and the first shorting electrode are formed of the same material, and the metal current collector of the second electrode and the second shorting electrode are formed of the same material. [25] In another example, in the first and second electrodes, the area ratio in which the uncoated region is formed among the holding portion regions is in the range of 5 to 15%. [26] In a specific example, the battery cell is a pouch-type lithium secondary battery. [27] [28] In addition, the present invention provides a method for evaluating an internal short circuit of a battery cell using the aforementioned battery cell. In one example, the method for evaluating an internal short circuit of a battery cell according to the present invention removes the first and second sub separators while the first and second short-circuit electrodes are electrically connected to each other during charging and discharging of the battery cell including the steps of [29] In a specific example, the step of removing the first and second sub separators may include, in the first and second sub separators, a structure in which the first and second shorting electrodes extend in opposite directions to a protruding direction, and the first and second sub separators It is carried out through the process of holding and pulling out the extended part of the sub separation membrane. Effects of the Invention [30] The battery cell for internal short circuit evaluation and the evaluation method using the same according to the present invention can easily induce an internal short circuit state of the battery cell and effectively evaluate the internal short circuit. Brief description of the drawing [31] 1 is an exploded perspective view of a battery cell for evaluation of an internal short circuit according to an embodiment of the present invention. [32] 2 to 9 are views illustrating an assembly sequence of a battery cell for evaluation of an internal short circuit according to an embodiment of the present invention. Modes for carrying out the invention [33] Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention based on the principle that it can be defined as [34] [35] The present invention provides a battery cell for evaluation of an internal short circuit. In one embodiment, the battery cell for evaluation of internal short circuit according to the present invention, [36] A holding part region in which a first electrode mixture layer is applied to one or both surfaces of a metal current collector, and a first electrode tab formed to protrude in one direction from the holding part region, but to which the first electrode mixture layer is not applied; a first electrode in which an uncoated region to which the first electrode mixture layer is not applied is formed in some of the sub-regions; [37] a first sub separator that covers the uncoated area of ​​the first electrode and has a larger area than the uncoated area; [38] a first shorting electrode formed at a position equal to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the first electrode; [39] a main separator interposed between both electrodes to cover the holding portion regions of the first and second electrodes; [40] a second shorting electrode formed at a position equivalent to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the second electrode; [41] a second sub separator that covers the uncoated area of ​​the second electrode and has a larger area than the uncoated area; and [42] A holding part region in which a second electrode mixture layer is applied on one or both surfaces of a metal current collector, and a second electrode tab formed to protrude in one direction from the holding part region, but to which the second electrode mixture layer is not applied; and a second electrode in which an uncoated region to which the second electrode mixture layer is not applied is formed in some of the sub-regions. [43] The internal short-circuit evaluation battery cell may induce an internal short circuit state of the battery cell only by removing or partially withdrawing the first and second sub-separators during the charging/discharging process of the battery cell. In addition, the present invention simulates lithium deposition in a lithium secondary battery, so that heat generation characteristics can be effectively evaluated when an internal short circuit occurs due to lithium deposition. [44] In one embodiment, each of the first and second shorting electrodes is a structure formed of a porous metal foil. In the present invention, each of the first and second short-circuit electrodes is formed of a porous metal foil, thereby providing a passage for movement of lithium ions during charging and discharging of the battery cell. For example, when the first electrode is an anode and has a structure formed of an aluminum foil, the first shorting electrode may be formed of a porous aluminum foil. In addition, in the case where the second electrode is a negative electrode and has a structure formed of copper foil, the second shorting electrode may be formed of a porous copper foil. [45] In a specific embodiment, each of the first and second shorted electrodes has a structure formed of a porous metal foil having a porosity of 50% or more. The first and second shorted electrodes each have a porosity in the range of 50% to 80%, 50% to 70%, or 55% to 65%. The porosity represents a fraction of an area in which voids are formed compared to the total area of ​​each short electrode. The range of the porosity is for smooth movement of lithium ions while maintaining the mechanical strength of each shorted electrode at a certain level or more. [46] In another specific embodiment, the first sub separator has a structure in which the first shorting electrode extends in a direction opposite to the direction in which the first shorting electrode protrudes from the holding portion region of the first electrode, and the second sub separator has a structure in which the second shorting electrode is the second It has a structure formed by extending in a direction opposite to the protruding direction from the holding portion region of the electrode. By controlling the extension direction of each sub-separator to be opposite to the protruding direction of each short-circuiting electrode, the electrical connection of each short-circuiting electrode is facilitated, and the removal or withdrawal of each sub-separating membrane is facilitated. [47] In one embodiment, in the first and second electrodes, the first and second electrode tabs are each independently formed in the same one direction or opposite to each other in the holding portion region, and the first and second shorting electrodes is a structure formed to protrude in a direction perpendicular to a direction in which the first and second electrode tabs are formed. In addition, the first and second sub separators have a structure in which the first and second shorting electrodes extend in opposite directions to the protruding direction. [48] The battery cell according to the present invention includes a structure in which the first electrode tab and the second electrode tab protrude in the same direction or are formed in opposite directions. For example, the first electrode tab has a structure that protrudes forward, and the second electrode tab has a structure that protrudes backward. In this case, the first and second shorted electrodes have a structure protruding to the left or right. This structural arrangement is for ease of operation when evaluating the battery cell. Specifically, the battery cell is a pouch-type or prismatic battery, and may have a structure in which the first and second electrode tabs are formed in the same direction or in different directions depending on the type of the battery. In contrast, by forming the positions of the first and second shorting electrodes in a direction perpendicular to the first and second electrode tabs, evaluation may be performed simultaneously with charging and discharging of the battery cell. [49] In one embodiment, the battery cell includes an electrode assembly having a structure in which a unit stack in which a first electrode, a main separator, and a second electrode are sequentially formed is repeated, and at least one of the unit stacks is a first electrode ; a first sub-separation membrane; a first shorting electrode; main separator; a second shorting electrode; a second sub-separation membrane; and a structure in which the second electrode is sequentially formed. The battery cell according to the present invention includes an electrode assembly having a structure in which a unit stack is repeated a plurality of times. Here, at least one of the unit stacks forming the electrode assembly is a structure for inducing and evaluating an internal short circuit. A structure for performing the induction and evaluation of such an internal short circuit includes: a first electrode; a first sub-separation membrane; a first shorting electrode; main separator; a second shorting electrode; a second sub-separation membrane; and a unit stack in which the second electrode is sequentially formed. [50] In a specific embodiment, the unit further includes a main separator interposed between the unit stack and the unit stack. The battery cell according to the present invention includes an electrode assembly having a structure in which a plurality of unit stacks are repeated, and a separate separator is required for electrical insulation between each unit stack. [51] In a more specific embodiment, the first and second sub-separators are a fabric separation membrane structure formed of a porous fabric made of a film material, and the main separator is a safety-reinforced separator structure in which inorganic particles are dispersed and coated on one or both surfaces of the fabric separator. The fabric separator means a separator made of a film material having a porous structure for the movement of lithium ions, and the safety-reinforced separator means a form in which inorganic particles are dispersed and coated on the surface of the fabric separator. [52] In one embodiment, the metal current collector of the first electrode and the first shorting electrode are formed of the same material, and the metal current collector and the second shorting electrode of the second electrode are formed of the same material. For example, when the first electrode is a positive electrode and is a foil formed of aluminum or an alloy thereof, the first shorting electrode is formed of aluminum or an alloy thereof and is porous. In addition, when the second electrode is a negative electrode and is a foil formed of copper or an alloy thereof, the second shorting electrode is formed of copper or an alloy thereof and is porous. [53] In another exemplary embodiment, in the first and second electrodes, the area ratio in which the uncoated area is formed in the holding part area is in the range of 5 to 15%. Specifically, the ratio of the area in which the uncoated area is formed in the holding part area is in the range of 5 to 10%, 10 to 15%, or 7 to 12%. In the present invention, the holding part region means a region excluding the electrode tab portion of the electrode current collector, and corresponds to a range to which the electrode mixture layer is applied. The uncoated region refers to a region in which the mixture layer is not applied to a part of the holding region. In addition, the area ratio in which the uncoated area is formed in the holding part area refers to the area ratio in which the uncoated area is formed among the maintenance part areas described above. [54] The battery cell is a secondary battery, specifically, a lithium secondary battery, and the form is a pouch-type or prismatic battery. For example, the battery cell is a pouch-type lithium secondary battery. [55] [56] In addition, the present invention provides a method for evaluating an internal short circuit of a battery cell using the aforementioned battery cell. In one embodiment, in the method for evaluating an internal short circuit of a battery cell according to the present invention, in a state in which the first and second short-circuit electrodes are electrically connected to each other during charging and discharging of the battery cell, the first and second sub separators are removing it. [57] Here, the removal of the first and second sub separators refers to a process in which a short circuit is induced inside a battery cell by drawing out extended portions of the first and second sub separators. The evaluation method according to the present invention may induce an internal short circuit state of the battery cell only by removing or partially withdrawing the first and second sub-separators during the charging/discharging process of the battery cell. [58] The method for evaluating an internal short circuit of a battery cell according to the present invention includes performing the evaluation of the battery cell in a state in which the internal short circuit of the battery cell is induced as described above. Performing the evaluation may be performed by measuring any one or more of voltage, current, and resistance of the battery cell. For example, performing the evaluation is performed by measuring a current to the battery cell. [59] In one embodiment, the step of removing the first and second sub separators may include, in the first and second sub separators, a structure in which the first and second shorting electrodes extend in a direction opposite to the protruding direction, and the first and second sub separators It is carried out through the process of holding the extended portion of the second sub separation membrane and pulling it out. [60] [61] The present invention provides a battery cell for evaluating an internal short circuit described above and a method for evaluating an internal short circuit of a battery cell using the same. The battery cell is a secondary battery, specifically, a lithium secondary battery. For example, a lithium secondary battery may include an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; a non-aqueous electrolyte for impregnating the electrode assembly; and a battery case containing the electrode assembly and the non-aqueous electrolyte. [62] The positive electrode has a structure in which a positive electrode mixture layer is laminated on one or both surfaces of a positive electrode current collector. The positive electrode active material may be each independently a lithium-containing oxide, and may be the same or different. As the lithium-containing oxide, a lithium-containing transition metal oxide may be used. In one example, the positive electrode mixture layer includes a conductive material and a binder polymer in addition to the positive electrode active material, and, if necessary, may further include a positive electrode additive commonly used in the art. [63] The positive active material may be a lithium-containing oxide, and may be the same or different. As the lithium-containing oxide, a lithium-containing transition metal oxide may be used. [64] For example, the lithium-containing transition metal oxide is Li x CoO 2 (0.5 [90] 100: first electrode [91] 120: first electrode tab [92] 110: first electrode holding part [93] 111: first electrode uncoated region [94] 200, 201: main separator [95] 210: first sub separation membrane [96] 220: second sub separator [97] 310: first shorting electrode [98] 320: second shorting electrode [99] 400: second electrode [100] 420: second electrode tab Claims [Claim 1] A holding part region in which a first electrode mixture layer is applied to one or both surfaces of a metal current collector, and a first electrode tab formed to protrude in one direction from the holding part region, but to which the first electrode mixture layer is not applied; a first electrode in which an uncoated region to which the first electrode mixture layer is not applied is formed in some of the sub-regions; a first sub separator that covers the uncoated area of ​​the first electrode and has a larger area than the uncoated area; a first shorting electrode formed at a position equal to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the first electrode; a main separator interposed between both electrodes to cover the holding portion regions of the first and second electrodes; a second shorting electrode formed at a position equivalent to the uncoated region of the first electrode and formed to protrude in one direction from the holding region of the second electrode; a second sub separator that covers the uncoated area of ​​the second electrode and has a larger area than the uncoated area; and a holding part region in which a second electrode mixture layer is applied on one or both surfaces of the metal current collector, and a second electrode tab formed to protrude in one direction from the holding part region, but to which the second electrode mixture layer is not applied, A battery cell for evaluation of internal short circuit, comprising a second electrode in which an uncoated region to which the second electrode mixture layer is not applied is formed in a portion of the holding region. [Claim 2] According to claim 1, wherein the first and second short-circuit electrode is a battery cell for internal short-circuit evaluation, characterized in that each has a structure formed of a porous metal foil. [Claim 3] According to claim 1, wherein the first and the second short-circuit electrode is a battery cell for internal short-circuit evaluation, characterized in that each has a structure formed of a porous metal foil having a porosity of 50% (v/v) or more. [Claim 4] The method of claim 1, wherein the first sub separator has a structure in which the first shorting electrode extends in a direction opposite to a direction in which the first shorting electrode protrudes from the holding portion region of the first electrode, and the second sub separator has a structure in which the second shorting electrode is the second electrode A battery cell for evaluation of an internal short circuit having a structure formed by extending in a direction opposite to the direction protruding from the holding part region of the [Claim 5] The method of claim 1, wherein in the first and second electrodes, the first and second electrode tabs each independently protrude in one direction or in a direction opposite to the one direction in the holding portion region, and the first and second shorting electrodes has a structure in which the first and second electrode tabs protrude in another direction perpendicular to the protruding direction, and the first and second sub separators are formed to extend in opposite directions to the protruding directions of the first and second shorting electrodes. A battery cell for measuring internal short circuits. [Claim 6] The method according to claim 1, wherein the battery cell comprises an electrode assembly having a structure in which a first electrode, a main separator, and a second electrode are sequentially formed in a repeated structure, and at least one of the unit stacks is a first electrode ; a first sub-separation membrane; a first shorting electrode; main separator; a second shorting electrode; a second sub-separation membrane; and a battery cell for evaluation of an internal short circuit, characterized in that the second electrode is sequentially formed. [Claim 7] The battery cell for evaluating an internal short circuit according to claim 6, further comprising a main separator interposed between the unit stack and the unit stack. [Claim 8] The internal short-circuit evaluation of claim 1, wherein the first and second sub-separators are a fabric separator structure formed of a porous fabric made of a film material, and the main separator is a safety-reinforced separator structure in which inorganic particles are dispersed and coated on one or both surfaces of the fabric separator. for battery cells. [Claim 9] The internal short circuit of claim 1, wherein the metal current collector of the first electrode and the first shorting electrode are formed of the same material, and the metal current collector and the second shorting electrode of the second electrode are formed of the same material. Battery cells for evaluation. [Claim 10] The battery cell for evaluating an internal short circuit according to claim 1, wherein, in the first and second electrodes, the area ratio in which the uncoated region is formed in the holding portion region is in the range of 5 to 15%. [Claim 11] The battery cell for evaluation of an internal short circuit according to claim 1, wherein the battery cell is a pouch-type lithium secondary battery. [Claim 12] In the method for evaluating an internal short circuit of a battery cell using the battery cell according to claim 1, in a state in which the first and second short-circuit electrodes are electrically connected to each other during charging and discharging of the battery cell, the first and second sub separators A method of evaluating an internal short circuit of a battery cell, comprising the step of removing it. [Claim 13] 13. The method of claim 12, wherein the removing of the first and second sub-separators comprises: the first and second sub-separators have a structure in which the first and second short-circuit electrodes extend in opposite directions to a protruding direction; A method for evaluating an internal short circuit of a battery cell, which is performed through a process of holding and drawing out an extended portion of the second sub separator.