The present invention relates to an electrode and an electrode assembly, and more particularly, to an electrode and an electrode assembly capable of preventing bending or twisting after a rolling process is completed. background art [5] In general, types of secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, lithium ion batteries, and lithium ion polymer batteries. These secondary batteries are used not only for small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and E-bikes, but also for large products that require high power, such as electric vehicles and hybrid vehicles, and surplus power generation. It is applied and used to a power storage device for storing power or renewable energy and a power storage device for backup. [6] In order to manufacture an electrode assembly, a cathode, a separator, and an anode are prepared and stacked. Specifically, the cathode active material slurry is applied to the cathode current collector, and the anode active material slurry is applied to the anode current collector to prepare a cathode and an anode. In addition, when a separator is interposed between the manufactured positive electrode and the negative electrode and stacked, unit cells are formed, and the unit cells are stacked with each other to form an electrode assembly. In addition, when the electrode assembly is accommodated in a specific case and an electrolyte solution is injected, a secondary battery is manufactured. [7] The manufacturing process of a secondary battery is largely divided into three steps: an electrode process, an assembly process, and a conversion process. And the electrode process is further divided into an active material mixing process, an electrode coating process, a rolling process, a slitting process, a winding process, and the like. Among them, the rolling process reduces the thickness of the electrode sheet after the coating process of the electrode mixture to increase the capacity density, and to increase the adhesiveness and adhesion between the electrode current collector and the electrode active material included in the electrode mixture, the high-temperature heated 2 This is a process of passing an electrode sheet between two rolling rolls and compressing it to a desired thickness and density. [8] 1 is a schematic diagram of a conventional electrode 100, and FIG. 2 is a schematic diagram showing a conventional electrode 100 being rolled. [9] As shown in FIG. 1, the electrodes 100 such as the positive electrode 101 (shown in FIG. 3) and the negative electrode 102 (shown in FIG. 3) include an active material application unit 1003 coated with an electrode active material 1002 and an active material uncoated portion 1004 to which the electrode active material 1002 is uncoated. The active material application unit 1003 is a region that directly generates power and occupies a large area of the electrode 100 . In addition, the active material uncoated portion 1004 is directly cut or a separate conductive member is connected to form the electrode tab 11 . [10] Conventionally, when an electrode sheet is passed between two rolling rolls 2 in a rolling process, as shown in FIG. 2, the active material application portion 1003 is relatively thick and receives more heat and pressure, and the active material application portion 1003 receives more heat and pressure. (1004) was relatively thin and received less heat and pressure. Therefore, due to the difference in heat and pressure, there is a problem in that the electrode 100 is bent or twisted after the rolling process is completed. In particular, as the loading amount of the electrode active material 1002 has recently increased as a cell with high energy density has been required, this problem has occurred more and more. [11] [Prior Art Document] (Patent Document 1) Japanese Unexamined Publication No. 2014-022116 DETAILED DESCRIPTION OF THE INVENTION technical challenge [12] The problem to be solved by the present invention is to provide an electrode and an electrode assembly that can prevent bending or twisting after the rolling process is completed. [13] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description. means of solving the problem [14] An electrode according to an embodiment of the present invention for solving the above problems includes an active material application unit in which an electrode active material is applied to at least one surface of an electrode current collector; and an active material uncoated portion formed on one side of the active material application portion, to which the electrode active material is uncoated, and including at least one slit extending from one end to the other end, wherein a hole is formed on a point where the slit and the active material application portion meet. This penetrating is formed. [15] In addition, the slit may have a straight line shape. [16] In addition, the slit may have a boundary line and an inclination between the active material uncoated part and the active material applied part. [17] In addition, the slit may have a curved shape. [18] In addition, the slit may have a curved shape having a constant curvature. [19] In addition, the slit may have a curved shape with a plurality of centers of curvature. [20] In addition, the slit may have a wave shape. [21] In addition, the width of the slit may be regularly or irregularly changed from one end to the other end. [22] In addition, the hole may have a shape of at least one of a circular shape, an elliptical shape, and a polygonal shape. [23] In addition, the slits may be formed in plurality, and one hole may be formed at one end of each of the plurality of slits. [24] Also, each hole may have a different shape. [25] An electrode assembly according to an embodiment of the present invention for solving the above problems is an electrode assembly formed by alternately stacking electrodes and separators, wherein the electrode is an active material coated with an electrode active material on at least one surface of an electrode current collector. applicator; and an active material uncoated portion formed on one side of the active material application portion, to which the electrode active material is uncoated, and including at least one slit extending from one end to the other end, wherein a hole is formed on a point where the slit and the active material application portion meet. This penetrating is formed. [26] Also, the slit formed in the anode of the electrode and the slit formed in the cathode of the electrode may have different shapes. [27] Further, the hole formed in the anode of the electrode and the hole formed in the cathode of the electrode may have different shapes. [28] Other specific details of the invention are included in the detailed description and drawings. Effects of the Invention [29] According to embodiments of the present invention, at least the following effects are provided. [30] By forming the slit in the active material uncoated portion of the electrode, it is possible to prevent the electrode from being bent or twisted even after the rolling process is completed. [31] In particular, since a slit having an appropriate shape is formed according to the degree of distortion of the electrode, which is different for each size and type of electrode, applied heat and pressure, the degree of bending or twisting of the electrode can be more efficiently prevented. [32] In addition, since a hole is formed at a point where the slit and the active material application unit meet, stress concentrated on one end of the slit can be dispersed to prevent cracks from occurring toward the active material application unit. [33] In particular, according to the stress distribution that causes cracks, which is different for each size and type of electrode, applied heat and pressure, a hole having an appropriate shape is formed, thereby preventing cracks from occurring toward the active material application portion more efficiently. [34] Effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification. Brief description of the drawing [35] 1 is a schematic diagram of a conventional electrode. [36] 2 is a schematic diagram showing a state of rolling a conventional electrode. [37] 3 is a schematic diagram of an electrode assembly according to a first embodiment of the present invention. [38] 4 is an assembly view of a pouch type secondary battery according to a first embodiment of the present invention. [39] 5 is a schematic diagram of an electrode according to a first embodiment of the present invention. [40] 6 is a schematic diagram of an electrode according to a second embodiment of the present invention. [41] 7 is a schematic diagram of an electrode according to a third embodiment of the present invention. [42] 8 is a schematic diagram of an electrode according to a fourth embodiment of the present invention. [43] 9 is a schematic diagram of an electrode according to a fifth embodiment of the present invention. [44] 10 is a schematic diagram of an electrode according to a sixth embodiment of the present invention. [45] 11 is a schematic diagram of an electrode according to a seventh embodiment of the present invention. [46] 12 is a schematic diagram of an electrode according to an eighth embodiment of the present invention. [47] 13 is a schematic diagram of an electrode according to a ninth embodiment of the present invention. [48] 14 is a schematic diagram of an electrode according to a tenth embodiment of the present invention. Mode for Carrying Out the Invention [49] Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification. [50] Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined. [51] Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements other than the recited elements. [52] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. [53] 3 is an electrode assembly 10 according to a first embodiment of the present invention More about this source textSource text required for additional translation information Send feedback Side panels History Saved Contribute 5,000 character limit. Use the arrows to translate more.) is a schematic diagram of [54] In order to manufacture the electrode assembly 10 according to the first embodiment of the present invention, first, a slurry in which a cathode active material 1012, a binder, and a plasticizer are mixed is mixed with a metal foil or metal mesh-type cathode containing aluminum. After applying to the current collector 1011, it is dried and pressed to manufacture a cathode (Cathode, 101). In addition, a slurry obtained by mixing the anode active material 1022, a binder, and a plasticizer is applied to the anode current collector 1021 in the form of a copper-containing metal foil or metal mesh, and then dried and pressed to form an anode (Anode, 102). manufacture The slurry may be typically formed by stirring a granular active material, an auxiliary conductor, a binder, a plasticizer, and the like in a state in which a solvent is added. At this time, if necessary, the slurry may further include a filler. And the solvent is removed in a subsequent process. Each of the positive electrode 101 and the negative electrode 102 may be manufactured in a sheet shape and mounted on a roll. [55] The electrode assembly 10 is formed by alternately stacking electrodes 100 and separators 103 . Specifically, the prepared anode 101 and cathode 102 are interposed between the electrodes 100 in order to insulate the two types of electrodes 100 and the electrodes 100 from each other, or of any one electrode 100. It may be a laminated structure having a separation membrane 103 disposed on the left or right side. In the laminated structure, positive electrodes 101 and negative electrodes 102 of a predetermined standard may be stacked with a separator 103 interposed therebetween, or may be wound in a jelly roll form. Alternatively, when the separator 103 is interposed and stacked between the manufactured anode 101 and cathode 102, unit cells are formed, and the unit cells are stacked with each other, as shown in FIG. 3, An electrode assembly 10 may also be formed. [56] The cathode current collector 1011 is generally manufactured to a thickness of 3 to 500 μm. The cathode current collector 1011 is usually made of a material that does not cause chemical change and has high conductivity. Such a material may be, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or a surface treatment of carbon, nickel, titanium, silver, or the like on the surface of aluminum or stainless steel, but is not limited thereto. In addition, fine irregularities may be formed on the surface of the cathode current collector 1011 to increase the adhesion of the cathode active material 1012 . In addition, the cathode current collector 1011 may be manufactured in various forms such as a film, sheet, foil, net, porous material, foam, or non-woven fabric. [57] In the case of a lithium secondary battery, the cathode active material 1012 may be, for example, a layered compound such as lithium cobalt oxide (LiCoO 2 ) or lithium nickel oxide (LiNiO 2 ), or a compound substituted with one or more transition metals; lithium manganese oxides such as Li 1+xMn 2-xO 4 (x is 0 to 0.33), LiMnO 3 , LiMn 2O 3 , and LiMnO 2 ; lithium copper oxide (Li 2 CuO 2 ); Vanadium oxides, such as LiV 3O 8, LiFe 3O 4, V 2O 5, and Cu 2V 2O 7; nickel (Ni) site-type lithium nickel oxide represented by the formula LiNi 1-xM xO 2 (M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3); represented by the formula LiMn 2-xM xO 2 (M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or Li 2Mn 3MO 8 (M = Fe, Co, Ni, Cu or Zn) lithium manganese composite oxide; LiMn 2O 4 in which Li part of the formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe 2 (MoO 4) 3 or the like. However, it is not limited only to these. [58] The conductive agent is typically added in an amount of 1 to 50% by weight based on the total weight of the mixture including the positive electrode active material 1012 . The conductive agent is usually made of a material that does not cause chemical change and has conductivity. Examples of such materials include graphite such as natural graphite and artificial graphite; carbon black such as carbon black, acetylene black, ketjen black, furnace black, channel black, lamp black, and thermal black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskeys such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives may be used. [59] The binder is a component that assists in binding the active material to the conductive agent and the current collector, and is typically added in an amount of 1 to 50% by weight based on the total weight of the mixture including the positive electrode active material 1012 . Such binders are typically polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butyrene rubber, fluororubber, various copolymers, and the like. [60] The filler is selectively used as a component that suppresses expansion of the positive electrode 101 . And, if it is a fibrous material that does not cause chemical change, it can generally be used as a filler. Fillers include, for example, olefinic polymers such as polyethylene and polypropylene; It may be a fibrous material such as glass fiber or carbon fiber. [61] The negative current collector 1021 is generally manufactured to a thickness of 3 to 500 μm. The anode current collector 1021 is usually made of a material that does not cause chemical change and has conductivity. Copper, stainless steel, aluminum, nickel, titanium, calcined carbon, which are the most representative of such materials, carbon, nickel, titanium, silver, etc. surface-treated on the surface of copper or stainless steel, aluminum-cadmium alloy, etc. to be. In addition, fine irregularities may be formed on the surface of the negative electrode current collector 1021 to increase bonding strength of the negative electrode active material 1022 . In addition, the anode current collector 1021 may be manufactured in various forms such as a film, sheet, foil, net, porous material, foam, or non-woven fabric. [62] The negative electrode active material 1022 may be, for example, carbon such as non-graphitizable carbon or graphite-based carbon; Li xFe 2O 3 (0=x=1), LixWO 2 (0=x=1), Sn xMe 1-xMe'yOz (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si , metal composite oxides such as elements of groups 1, 2 and 3 of the periodic table, halogens; 0