Secondary battery

Abstract

To provide a secondary battery capable of preventing an increase in an overall thickness and ensuring insulation.SOLUTION: The present disclosure provides a secondary battery, including: an electrode assembly; a pouch-shaped case housing the electrode assembly; a first tape attached to a side part of the case; and a second tape attached to an upper part of the case. The first tape and the second tape are formed so as not to partially overlap each other in a first region corresponding to an upper corner of the case.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to secondary batteries. [Background technology]

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and video cameras, while high-capacity secondary batteries are widely used as motor drive power sources and power storage batteries in hybrid vehicles, electric vehicles, and the like. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The above information disclosed in the Background of the Invention section is intended solely to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a secondary battery that can prevent an increase in the overall thickness and ensure insulation.

[0005] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0006] A secondary battery according to one embodiment of the present invention for solving the above technical problems includes an electrode assembly, a pouch-type case that houses the electrode assembly, a first tape attached to a side of the case, and a second tape attached to an upper part of the case, wherein the first tape and the second tape are formed so as not to overlap each other in a first region that corresponds to an upper corner of the case.

[0007] The first tape may also be formed to extend at a constant width along the side of the case and to have a reduced width in the first region.

[0008] The case may also have a wide, flat front surface, narrow, flat sides, and a transition portion connecting the front surface and the sides, and the first tape and the second tape may be formed so as not to overlap on the front surface of the case in the first region.

[0009] The case may also have a wide, flat front, narrow, flat sides, and a transition portion connecting the front and the sides, and the first tape and the second tape may be formed to overlap at the transition portion of the case in the first region.

[0010] The case may also have a wide, flat front, narrow, flat sides, and a transition portion connecting the front and sides, and the first tape and the second tape may be formed to overlap the transition portion and sides of the case in the first region.

[0011] The case may also have a wide, flat front, narrow, flat sides, and a transition portion connecting the front and sides, and the first tape may include a first section located in the first area and formed across the transition portion and side of the case, and a second section located outside the first area and formed across the front, transition portion, and side of the case.

[0012] Furthermore, the first tape may have the first section and the second section formed integrally.

[0013] Additionally, the second tape may extend with a width corresponding to the length of the first section of the first tape.

[0014] Also, a sub-section of the second section of the first tape adjacent to the first section may be formed only at the transition portion and the side of the case.

[0015] In addition, some sub-sections of the second section of the first tape adjacent to the first section may be formed to have a width that gradually decreases toward the first section of the first tape.

[0016] In addition, the subsection of the first tape may have a length 1 to 3 times the width of the transition portion of the case when the front surface of the case is viewed vertically.

[0017] The first tape may extend at a constant width along the side of the case and be formed to have a reduced width in the first region, and the second tape may extend at a constant width along the top of the case and be formed to have a reduced width in the first region.

[0018] The case may have a wide, flat front surface, narrow, flat sides, and a transition portion connecting the front surface and the side surface, and the first region may be a region on the side of the case that is within approximately 10% of the total length of the front surface of the case from the top end of the front surface of the case.

[0019] The case may also have a wide, flat front, narrow, flat sides, and a transition portion connecting the front and sides, and the second tape may extend beyond the front of the case and terminate at the transition portion of the case.

[0020] The case may also have a wide, flat front, narrow, flat sides, and a transition portion connecting the front and sides, and the second tape may extend beyond the front and transition portion of the case and terminate at the side of the case. [Effects of the Invention]

[0021] According to the present invention, a secondary battery can be provided in which a first tape and a second tape are attached to the sides and top of a pouch-shaped case, respectively, and the first tape and the second tape are formed so as not to overlap in areas corresponding to the upper corners of the case, particularly on the front surface of the case, thereby preventing an increase in overall thickness due to tape overlap.

[0022] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0023] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a front view showing a secondary battery according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a portion II in FIG. [Figure 3] Figure 3 shows Figure 2 with the second tape removed. [Figure 4] FIG. 4 is an exploded view illustrating the internal structure of the secondary battery according to the first embodiment of the present invention. [Figure 5] FIG. 5 shows a secondary battery according to a second embodiment of the present invention, and is a diagram showing a portion corresponding to FIG. [Figure 6]FIG. 6 shows a secondary battery according to a third embodiment of the present invention, and is a diagram showing a portion corresponding to FIG. [Figure 7] FIG. 7 shows a secondary battery according to a fourth embodiment of the present invention, and is a diagram showing a portion corresponding to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be construed as being limited to their ordinary and dictionary meanings, but should be construed in a way that corresponds to the technical concept of the present invention, based on the principle that the inventor himself can appropriately define the concept of terms in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical concept of the present invention, and therefore, at the time of this application, various equivalents and modifications may be available.

[0026] Also, as used in this specification, "comprise" and / or "comprising" specify the presence of stated shapes, numbers, steps, operations, members, elements and / or groups thereof, but do not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements and / or groups.

[0027] In addition, to facilitate understanding of the invention, the accompanying drawings may not be drawn to scale, and the dimensions of some components may be exaggerated. In addition, the same reference numerals may be used to refer to the same components in different embodiments.

[0028] A statement that two comparison objects are "identical" means that they are "substantially identical." Therefore, "substantially identical" may include deviations that are considered low in the art, for example, deviations within 5%. Furthermore, uniformity of any parameter in a given region may mean uniformity from an average perspective.

[0029] Furthermore, although terms such as "first" and "second" are used to indicate various components, these terms are not intended to limit the components. These terms are used merely to distinguish one component from another, and unless otherwise specified, a first component can also be a second component.

[0030] Throughout the specification, unless otherwise stated, each element may be singular or plural.

[0031] Hereinafter, when an arbitrary configuration is placed on the "top (or bottom)" of a component or "above (or below)" a component, it may mean not only that the arbitrary configuration is placed in contact with the upper surface (or lower surface) of the component, but also that another configuration may be interposed between the component and the arbitrary configuration placed above (or below) the component.

[0032] Furthermore, when a component is said to be "coupled," "coupled," or "connected" to another component, it includes not only the case where the components are directly coupled or connected to each other, but also the case where other components are "interposed" between the components, or the case where each component is "coupled," "coupled," or "connected" through other components. Furthermore, when it is said that a part is electrically coupled to another part, it includes not only the case where they are directly coupled, but also the case where they are coupled with another element interposed therebetween.

[0033] Throughout the specification, "A and / or B" means A only, B only, or A and B, unless otherwise specified. That is, "and / or" includes all or any combination of the listed items. "C-D" means at least C and at most D, unless otherwise specified.

[0034] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0035] FIG. 1 is a front view showing a secondary battery 100 according to a first embodiment of the present invention, FIG. 2 is an enlarged view of part II in FIG. 1, and FIG. 3 is a view of FIG. 2 with the second tape 160 removed.

[0036] The secondary battery 100 according to the first embodiment of the present invention includes an electrode assembly 110 , a case 120 , a first electrode lead 130 , a second electrode lead 140 , a first tape 150 , and a second tape 160 .

[0037] 1 to 3 show only the external appearance of the secondary battery 100 according to the first embodiment of the present invention, and do not show the electrode assembly 110, the first electrode lead 130, the second electrode lead 140, etc. Therefore, first, with reference to FIG. 4, the internal structure of the secondary battery 100 according to the first embodiment of the present invention, including the electrode assembly 110, the first electrode lead 130, the second electrode lead 140, etc., will be briefly described.

[0038] FIG. 4 is an exploded view illustrating the internal structure of the secondary battery 100 according to the first embodiment of the present invention, with the first tape 150 and the second tape 160 omitted.

[0039] Referring to FIG. 4 , the electrode assembly 110 may be formed by winding or stacking a laminate of a first electrode plate 111, a separator 112, and a second electrode plate 113, each formed in the shape of a thin plate or film. If the electrode assembly 110 is a wound laminate, the winding axis may be parallel to the longitudinal direction of the case 120. The electrode assembly 110 may also be a stacked type rather than a wound type, and the present invention does not limit the shape of the electrode assembly 110. The electrode assembly 110 may also be a Z-stack electrode assembly in which the first electrode plate 111 and the second electrode plate 113 are inserted on both sides of the separator 112 bent in a Z-stack configuration. One or more electrode assemblies 110 may be stacked with their longitudinal sides adjacent to each other and housed inside the case 120, and the present invention does not limit the number of electrode assemblies 110. The first electrode plate 111 of the electrode assembly 110 may serve as a negative electrode, and the second electrode plate 113 may serve as a positive electrode, or vice versa.

[0040] The first electrode plate 111 is formed by coating a first electrode active material, such as graphite or carbon, on a first electrode current collector plate formed of a metal foil such as copper, a copper alloy, nickel, or a nickel alloy, and may include a first electrode tab (or first uncoated portion) 111a, which is an area where the first electrode active material is not coated. The first electrode tab 111a may serve as a path for current flow between the first electrode plate 111 and the first electrode lead 130. In some examples, the first electrode tab 111a may be formed by cutting the first electrode plate 111 to protrude from one side in advance when manufacturing the first electrode plate 111, or may protrude further from one side than the separator 112 without additional cutting.

[0041] The second electrode plate 113 is formed by coating a second electrode active material, such as a transition metal oxide, on a second electrode current collector plate formed of a metal foil, such as aluminum or an aluminum alloy, and may include a second electrode tab (or second uncoated portion) 113a, which is an area where the second electrode active material is not coated. The second electrode tab 113a may serve as a path for current flow between the second electrode plate 113 and the second electrode lead 140. In some examples, the second electrode tab 113a may be formed by cutting the second electrode plate 113 to protrude from the other side in advance when manufacturing the second electrode plate 113, or may protrude further from the other side than the separator 112 without additional cutting.

[0042] In some examples, the first electrode tap 111a may be located on the side surface of the left end of the electrode assembly 110, and the second electrode tap 113a may be located on the side surface of the right end of the electrode assembly 110, or may be located on one surface in the same direction. Here, left and right are used as arbitrary references for convenience of explanation, and their positions may change when the secondary battery 100 is rotated left and right or up and down.

[0043] In some examples, the electrode assembly 110 may be housed in a case 120 together with an electrolyte.

[0044] The positive electrode active material may be a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound). Specifically, one or more of composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0045] The composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel-manganese-based oxides, and combinations thereof.

[0046] As an example, a compound represented by any one of the following chemical formulas can be used: Li a A 1-b X b O 2-c D c (0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05), Li a Mn 2-b X b O 4-c D c (0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05), Li a Ni 1-b-c Co b X c O 2-α D α (0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.5, 0<α<2), Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.5, 0<α<2), Li a Ni b Co c L 1 d G e O2 (0.90≦a≦1.8, 0≦b≦0.9, 0≦c≦0.5, 0≦d≦0.5, 0≦e≦0.1), Li a NiG b O2 (0.90≦a≦1.8, 0.001≦b≦0.1), Li a CoG b O2 (0.90≦a≦1.8, 0.001≦b≦0.1), Li a Mn 1-b G b O2 (0.90≦a≦1.8, 0.001≦b≦0.1), Li a Mn2G b O4 (0.90≦a≦1.8, 0.001≦b≦0.1), Li a Mn 1-g G g PO4(0.90≦a≦1.8, 0≦g≦0.5), Li (3-f) Fe2(PO4)3(0≦f≦2);Li aFePO4(0.90≦a≦1.8).

[0047] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 is Mn, Al or a combination thereof.

[0048] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0049] The content of the positive electrode active material may be 90% by weight to 99.5% by weight relative to 100% by weight of the positive electrode active material layer, and the contents of the binder and conductive material may each be 0.5% by weight to 5% by weight relative to 100% by weight of the positive electrode active material layer.

[0050] The current collector may be made of Al, but is not limited to this.

[0051] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of being doped and dedoped with lithium, or a transition metal oxide.

[0052] The material capable of reversibly intercalating / deintercalating lithium ions may include a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon include graphite, such as natural graphite or artificial graphite, and examples of amorphous carbon include soft carbon, hard carbon, mesophase pitch carbide, and calcined coke.

[0053] As the substance capable of being doped and undoped with lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0054] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in a form in which amorphous carbon is coated on the surface of silicon particles.

[0055] The silicon-carbon composite may further contain crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0056] The negative electrode for a lithium secondary battery includes a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer contains a negative electrode active material and may further contain a binder and / or a conductive material.

[0057] For example, the negative electrode active material layer may contain 90% to 99% by weight of the negative electrode active material, 0.5% to 5% by weight of the binder, and 0% to 5% by weight of the conductive material.

[0058] As the binder, a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof can be used. When an aqueous binder is used as the negative electrode binder, it may further contain a cellulose-based compound capable of imparting viscosity.

[0059] As the negative electrode current collector, one selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof can be used.

[0060] The electrolyte for the lithium secondary battery contains a non-aqueous organic solvent and a lithium salt.

[0061] The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reactions of the battery can migrate.

[0062] The non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more.

[0063] When a carbonate solvent is used, a mixture of a cyclic carbonate and a chain carbonate can be used.

[0064] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. Such separators can be made of polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films of two or more of these materials.

[0065] The separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0066] The organic material may include a polyvinylidene fluoride polymer or a (meth)acrylic polymer.

[0067] The inorganic material may include, but is not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0068] The organic material and the inorganic material may be mixed in one coating layer, or may be stacked in a coating layer containing an organic material and a coating layer containing an inorganic material.

[0069] The case 120 is formed in a so-called pouch shape and accommodates the electrode assembly 110 therein.

[0070] More specifically, the case 120 includes a first pouch member 121 having a concave internal space 121a formed therein to accommodate the electrode assembly 110, and a second pouch member 122 that is formed substantially flat and covers the first pouch member 121.

[0071] The first pouch member 121 may be formed, for example, by preparing a substantially flat sheet and then performing a forming process using a punch in the middle portion while fixing the edges, thereby forming the concave internal space 121a. The punch preferably has curved edges to prevent stress concentration near the edges. The resulting internal space 121a has a substantially flat bottom surface (corresponding to the "front surface F of the case 120" described below), a substantially flat inner surface (corresponding to the "side surface S of the case 120" described below), and a curved transition portion between the bottom surface and the inner surface (corresponding to the "transition portion T of the case 120" described below).

[0072] The first pouch member 121 and the second pouch member 122 can be manufactured separately, or can be manufactured integrally and foldably connected at the bottom end. Figure 4 illustrates the latter case.

[0073] The first pouch member 121 and the second pouch member 122 may also be joined along their edges. This portion is also called a "terrace portion," and the terrace portions on both sides may be folded at approximately 90° toward the first pouch member 121 side to save space after joining.

[0074] The first electrode lead 130 is drawn out from the first electrode plate 111 of the electrode assembly 110 to the upper side of the case 120, passing between the first pouch member 121 and the second pouch member 122. The first electrode lead 130 may be provided with an insulating member 131 at a portion where it contacts the case 120 to prevent an electrical short circuit to the case 120.

[0075] The second electrode lead 140 is drawn out from the second electrode plate 113 of the electrode assembly 110 to the upper end of the case 120, passing between the first pouch member 121 and the second pouch member 122. The second electrode lead 140 may be provided with an insulating member 141 at a portion where it contacts the case 120 to prevent an electrical short circuit to the case 120.

[0076] Furthermore, the first tape 150 and the second tape 160 will be described with reference to FIGS.

[0077] For reference, FIG. 1 shows the first pouch member 121 as viewed from the front, with the terrace portions on both sides folded at approximately 90° toward the first pouch member 121, with a first tape 150 attached thereon, and the first electrode lead 130 and the second electrode lead 140 arranged so as to be connected to a protection circuit module (PCM) (not shown), with a second tape 160 attached thereon.

[0078] Hereinafter, with reference to FIG. 1, the relatively wide and substantially flat portion seen from the front will be referred to as the "front surface F of case 120," the relatively narrow and substantially flat portion located on the side thereof will be referred to as the "side surface S of case 120," and the portion forming a curved surface between the front surface F and side surface S of case 120 will be referred to as the "transition portion T of case 120."

[0079] For ease of understanding, the first tape 150 and the second tape 160 are each shown hatched.

[0080] The first tape 150 is attached to the side of the case 120 and serves to structurally fix the side of the case 120 while electrically insulating the side of the case 120 from the outside.

[0081] The second tape 160 is attached to the top of the case 120 and serves to structurally fix the top of the case 120 while electrically insulating the top of the case 120 from the outside.

[0082] In the secondary battery 100 according to the first embodiment of the present invention, the second tape 160 can extend generally along the top of the case 120 with a substantially constant width.

[0083] If the first tape 150 and the second tape 160 overlap in the area corresponding to the upper corner of the case 120, the overall thickness of the secondary battery 100 increases by the thickness of the tapes, which is detrimental to a compact design. To solve this problem, the secondary battery 100 according to the first embodiment of the present invention has an overlap prevention structure applied to the first tape 150 in the area corresponding to the upper corner of the case 120.

[0084] Here, the area corresponding to the upper corner of the case 120 may refer to, for example, an area on the side of the case 120 that is within approximately 10% of the total length of the front surface F of the case 120 from the top end of the front surface F of the case 120; hereinafter, for ease of explanation, this area will be referred to as the "first area A1," and the remaining area will be referred to as the "second area A2."

[0085] For reference, the dotted lines indicating the first area A1 and the second area A2 are drawn slightly larger for ease of illustration, i.e., to prevent overlapping and confusion in the drawings. However, a person of ordinary skill in the art will understand by reading the following description that the height of the first area A1 corresponds to the length L1 of the first section S1 of the first tape 150 and the width W2 of the second tape 160, and that the width of the second area A2 corresponds to the width W1 of the second section S2 of the first tape 150.

[0086] More specifically, referring to Figures 2 and 3, the first tape 150 extends along the side of the case 120 in the second region A2 with a substantially constant width W1, and in the first region A1, an overlap avoidance structure is applied, forming the width W1 to decrease.

[0087] In other words, the first tape 150 includes a first section S1 located in a first area A1 and a second section S2 located in a second area A2.

[0088] The second section S2 is formed across the front face F, the transition section T, and the side face S of the case 120, whereas the first section S1 is not formed on the front face F of the case 120, but is formed only on the transition section T and the side face S of the case 120.

[0089] In such a first tape 150, the first section S1 and the second section S2 may be integrally formed.

[0090] The second tape 160 extends with a width W2 corresponding to the length L1 of the first section S1 of the first tape 150.

[0091] The second tape 160 may extend beyond the front face F of the case 120 and terminate at the transition T of the case 120, or may extend beyond the transition T of the case 120 and terminate at the side S of the case 120.

[0092] As a result, the first tape 150 and the second tape 160 do not overlap on the front surface F of the case 120 in the first region A1, and this overlapping can be prevented from increasing the overall thickness of the secondary battery 100.

[0093] In addition, the first tape 150 and the second tape 160 overlap at the transition portion T and the side surface S of the case 120 in the first region A1, so that the continuity of the insulation can be reliably ensured.

[0094] FIG. 5 relates to a secondary battery according to a second embodiment of the present invention, and shows a portion corresponding to FIG.

[0095] In the case of the secondary battery 100 according to the first embodiment of the present invention described in relation to Figure 2, an overlap avoidance structure was applied only to the first section S1 in the first tape 150, but the secondary battery according to the second embodiment of the present invention differs in that an overlap avoidance structure is also applied to some sub-sections S2-1 of the second section S2 adjacent to the first section S1 in the first tape 250.

[0096] The remaining features are substantially the same as those of the secondary battery 100 according to the first embodiment of the present invention, so a repeated description thereof will be omitted and the following description will focus on the above differences.

[0097] Referring to FIG. 5, in a secondary battery according to another embodiment of the present invention, a first tape 250 includes a first section S1 located in a first region A1 and a second section S2 located in a second region A2.

[0098] The first section S1 is not formed on the front face F of the case 120, but is formed only on the transition portion T and the side face S of the case 120.

[0099] The second section S2 is formed entirely across the front face F, the transition section T and the side face S of the case 120, except that some sub-sections S2-1 adjacent to the first section S1, like the first section S1, are not formed on the front face F of the case 120, but are formed only on the transition section T and the side face S of the case 120.

[0100] The subsection S2-1 may have a length L2 that is 1 to 3 times the width W3 of the transition portion T of the case 120 when the front face F of the case 120 is viewed vertically.

[0101] This allows the subsection S2-1 to provide extra space, ensuring that the first tape 250 and the second tape 160 do not overlap on the front surface F of the case 120 in the first area A1, even if the first tape 250 or the second tape 160 is attached somewhat inaccurately during the manufacturing process.

[0102] FIG. 6 relates to a secondary battery according to a third embodiment of the present invention, and shows a portion corresponding to FIG.

[0103] Compared with the secondary battery according to the second embodiment of the present invention described with reference to FIG. 5, the secondary battery according to the third embodiment of the present invention differs in that in the first tape 350, a sub-section S2-1 of the second section S2 adjacent to the first section S1 has a width W1 that gradually decreases toward the first section S1.

[0104] Although FIG. 5 illustrates the subsection S2-1 as being formed linearly, the subsection S2-1 may also be formed as a curved line.

[0105] This prevents the first tape 350 from easily tearing due to stress concentration when the width suddenly decreases from the subsection S2-1.

[0106] The remaining features are substantially the same as those of the secondary battery according to the second embodiment of the present invention, and therefore, a repeated description thereof will be omitted.

[0107] FIG. 7 relates to a secondary battery according to a fourth embodiment of the present invention, and shows a portion corresponding to FIG.

[0108] In the case of the secondary battery according to the third embodiment of the present invention described with reference to FIG. 6, the overlap avoidance structure is applied only to the first tape 350, but the secondary battery according to the fourth embodiment of the present invention differs in that the overlap avoidance structure is also applied to the second tape 460.

[0109] The remaining features are substantially the same as those of the secondary battery according to the third embodiment of the present invention, so a repeated description thereof will be omitted and the following description will focus on the differences.

[0110] Referring to FIG. 7, in the secondary battery according to the fourth embodiment of the present invention, an overlap avoidance structure is applied to the first tape 350 in the same manner as described above.

[0111] Furthermore, the second tape 460 is formed so as to extend generally along the top of the case 120 with a substantially constant width W2, and so as to decrease in the width W2 in the first region A1.

[0112] The second tape 460 may extend beyond the front face F of the case 120 and terminate at the transition T of the case 120, or may extend beyond the transition T of the case 120 and terminate at the side S of the case 120.

[0113] This makes it possible to more reliably ensure that the first tape 350 and the second tape 460 do not overlap on the front surface F of the case 120 in the first area A1 by applying the overlap avoidance structure not only to the first tape 350 but also to the second tape 460.

[0114] The secondary battery according to the fourth embodiment of the present invention has been described as a combination of "a shape similar to the first tape 350 of the secondary battery according to the third embodiment of the present invention" and "an overlap avoidance structure being applied to the second tape 460." However, as further embodiments not shown in this specification, a combination of "a shape similar to the first tape 150 of the secondary battery 100 according to the first embodiment of the present invention" and "an overlap avoidance structure being applied to the second tape," a combination of "a shape similar to the first tape 250 of the secondary battery according to the second embodiment of the present invention" and "an overlap avoidance structure being applied to the second tape," etc. may be considered, and all such combinations fall within the scope of the technical concept of the present invention.

[0115] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0116] 100 Secondary battery 110 Electrode assembly 111 First electrode plate 111a first electrode tap 112 Separator 113 Second electrode plate 113a second electrode tap 120 cases 121 first pouch member 121a Interior space 122 second pouch member 130 first electrode lead 131, 141 insulating member 140 Second electrode lead 150, 250, 350 First Tape 160, 460 Second Tape A1 First Area A2 Second Area F Front of Case 120 L1: Length of the first section S1 of the first tape 150 L2 Length of subsection S2-1 S Case 120 side S1 First Section S2 Second Section S2-1 Lower Section T Case 120 conversion section W1: Width of the second section S2 of the first tape 150 W2: Width of the first section S1 of the second tape 160 W3 Width of the transition part T of case 120

Claims

1. an electrode assembly; a pouch-shaped case that accommodates the electrode assembly; a first tape attached to a side of the case; a second tape attached to the top of the case; The secondary battery, wherein the first tape and the second tape are formed so as not to overlap each other in a first region corresponding to an upper corner of the case.

2. The secondary battery according to claim 1 , wherein the first tape extends at a constant width along the side of the case and is formed so as to have a reduced width in the first region.

3. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; The secondary battery according to claim 1 , wherein the first tape and the second tape are formed so as not to overlap on the front surface of the case in the first region.

4. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; The secondary battery according to claim 1 , wherein the first tape and the second tape are formed to overlap at a transition portion of the case in the first region.

5. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; The secondary battery according to claim 1 , wherein the first tape and the second tape are formed to overlap a transition portion of the case at the side in the first region.

6. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; The first tape comprises: a first section located in the first region and formed across the transition portion and side of the case; a second section located outside the first area and formed across the front surface, the transition portion, and the side surface of the case, the secondary battery according to claim 1 .

7. The secondary battery according to claim 6 , wherein the first section and the second section of the first tape are integrally formed.

8. 7. The secondary battery according to claim 6, wherein the second tape extends with a width corresponding to the length of the first section of the first tape.

9. The secondary battery of claim 6 , wherein a subsection of the second section of the first tape adjacent to the first section is formed only at a transition portion and a side surface of the case.

10. 7. The secondary battery of claim 6, wherein a width of a subsection of the second section of the first tape adjacent to the first section is gradually reduced toward the first section of the first tape.

11. 11. The secondary battery according to claim 9, wherein the subsection of the first tape has a length 1 to 3 times the width of the transition portion of the case when the front surface of the case is viewed vertically.

12. the first tape extends at a constant width along the side of the case and is formed to decrease in width in the first region; The secondary battery according to claim 1 , wherein the second tape extends at a constant width along the top of the case and is formed so as to decrease in width in the first region.

13. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; The secondary battery according to claim 1 , wherein the first region is a region on the side of the case that is within approximately 10% of the total length of the front surface of the case from the top end of the front surface of the case.

14. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; 2. The secondary battery of claim 1, wherein the second tape extends beyond the front surface of the case and terminates at a transition in the case.

15. The case has a wide, flat front surface, narrow, flat side surfaces, and a transition portion connecting the front surface and the side surfaces; 2. The secondary battery of claim 1, wherein the second tape extends beyond the front face and transition of the case and terminates at a side face of the case.

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