Secondary battery

Abstract

An embodiment of the present invention relates to a secondary battery. The secondary battery according to the embodiment of the present invention may comprise: an electrode assembly having a first electrode plate and a second electrode plate; a cylindrical can for accommodating the electrode assembly; a cathode terminal coupled to one end of the can; a first current collector plate disposed between the first electrode plate and the cathode terminal and electrically connected to the first electrode plate and the cathode terminal; a second current collector plate electrically connected to the second electrode plate and the can; a cap plate coupled to the other end of the can; and an insulating tape which is disposed between the one end of the can and the first current collector plate so as to cover the first current collector plate, and which has a plurality of cut portions. According to the embodiment of the present invention, insulation can be easily achieved between a cathode-side end portion and a peripheral side surface portion when the electrode assembly is inserted into the can. In addition, if an odd number of cutting lines is applied to the insulating tape, the thickness of the side surface portion can be reduced.

Description

secondary batteries

[0001] An embodiment of the present invention relates to a secondary battery.

[0002] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include an electrode assembly comprising a positive and negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0004] An embodiment of the present invention provides a secondary battery having an improved insulation structure.

[0005] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0006] A secondary battery according to an embodiment of the present invention may include: an electrode assembly having a first electrode plate and a second electrode plate; a cylindrical can accommodating the electrode assembly; a positive electrode terminal coupled to one end of the can; a first current collector plate disposed between the first electrode plate and the positive electrode terminal and electrically connected to the first electrode plate and the positive electrode terminal; a second current collector plate electrically connected to the second electrode plate and the can; a cap plate coupled to the other end of the can; and an insulating tape disposed between one end of the can and the first current collector plate to cover the first current collector plate, the insulating tape having a plurality of cutouts.

[0007] The above insulating tape may be circular in shape with a hollow portion formed therein.

[0008] It is characterized by having a diameter larger than the diameter of the electrode assembly.

[0009] The above cut portion can be positioned along the outer circumferential direction.

[0010] The above-mentioned incision may include a cutting line cut in a straight line shape and a cutting hole cut in a preset shape.

[0011] The above incision line and the above incision hole can be connected to each other.

[0012] The above-mentioned incision hole is characterized by being one of circular, oval, and polygonal shapes.

[0013] The above incisions may be provided in odd numbers.

[0014] The above incisions may be provided in an odd number between 11 and 19.

[0015] The above insulating tape is characterized in that the surface facing the first collector plate is an adhesive surface.

[0016] The can has a top surface in the shape of a disc and a side surface extending from the top surface, the positive terminal is coupled to the top surface, and the cap plate can be coupled to an end of the side surface.

[0017] It may further include a first gasket that insulates between the positive terminal and the upper surface, and a second gasket that insulates between the cap plate and the side.

[0018] The above side portion may include a beading portion formed to be concave toward the inside, and a crimping portion formed by bending an end of the side portion while the cap plate is coupled.

[0019] The second gasket can be inserted between the beading portion and the crimping portion.

[0020] The second collector plate may further include a plurality of negative leads electrically connecting the second collector plate to the side portion.

[0021] The above negative lead may have one end connected to the second collector plate, and the other end inserted between the beading portion and the second gasket.

[0022] According to an embodiment of the present invention, when inserting the electrode assembly into a can, insulation can be easily achieved between the positive end and the peripheral side.

[0023] Additionally, if the cutting lines of the insulating tape are applied in an odd number, the thickness of the side portion may be reduced.

[0024] In addition, the insulating tape can be inserted together with the insertion process of the electrode assembly without a separate insulating tape attachment process, and the concentricity of the electrode assembly and the can can be maintained.

[0025] 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 can be clearly understood by those skilled in the art from the description of the invention described below.

[0026] 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 idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0027] FIG. 1 is a perspective view illustrating a cylindrical secondary battery according to one embodiment of the present invention.

[0028] Figure 2 is a cross-sectional view of a cylindrical secondary battery according to Figure 1.

[0029] FIG. 3 is a drawing illustrating an electrode assembly and an insulating tape according to one embodiment of the present invention.

[0030] FIGS. 4A to 4D are plan views illustrating the shape of a cut portion of an insulating tape according to embodiments of the present invention.

[0031] FIGS. 5A to 5E are plan views illustrating the number of cut portions of an insulating tape according to embodiments of the present invention.

[0032] FIG. 6 is a drawing illustrating an assembly process of an electrode assembly and a can according to one embodiment of the present invention.

[0033] FIGS. 7 and 8 are perspective views illustrating a battery pack including an exemplary secondary battery according to the present invention.

[0034] FIGS. 9 and 10 are perspective and side views illustrating a vehicle including an exemplary battery pack according to the present invention.

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0036] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0037] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0038] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0039] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0040] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0041] Any configuration being placed on (or below) a component or above (or below) a component may mean not only that any 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 any configuration placed on (or below) the component.

[0042] Additionally, when it is described that a component is connected, coupled, or connected to another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may be interposed between the components, or that each component may be connected, coupled, or connected through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0043] When reference is made throughout the specification to A and / or B, this means A, B, or A and B, unless otherwise stated. That is, and / or includes all or any combination of the listed items. When reference is made to C through D, this means C or more and D or less, unless otherwise stated.

[0044] 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.

[0045] Hereinafter, a secondary battery according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0046] Fig. 1 is a perspective view illustrating a cylindrical secondary battery according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of the cylindrical secondary battery according to Fig. 1. Fig. 3 is a drawing illustrating an electrode assembly and an insulating tape according to one embodiment of the present invention.

[0047] Referring to FIGS. 1 to 3, a secondary battery (10) according to one embodiment of the present invention may include a can (100), an electrode assembly (200), a first current collector (300), a second current collector (400), a negative electrode lead (450), an insulating tape (500), a positive electrode terminal (600), a first gasket (700), a cap plate (800), and a second gasket (900).

[0048] Referring to FIGS. 1 and 2, a can (100) constitutes the outer shape of a secondary battery (10) and may have a cylindrical shape with one end opened. The can (100) may include or be referred to as a case, a housing, or an outer material. The can (100) may include a top portion (110) in a disc shape and a side portion (120) in a cylindrical shape extending downward from the top portion (110). A positive terminal (600) and a first gasket (700) may be coupled to the top portion (110). The lower portion of the side portion (120) is open. A beading portion (122) and a crimping portion (124) may be formed at the lower portion of the side portion (120). In the present embodiment, an example in which the lower portion of the can (100) is open is described, but conversely, the upper portion of the can (100) may be open.

[0049] When assembling the electrode assembly (200) into the can (100), the upper portion (110) is placed downward, the electrode assembly (200) is inserted, and then the beading portion (122) is formed. The beading portion (122) can prevent the electrode assembly (200) from coming off. The beading portion (122) can be provided by processing the lower end of the side portion (120) to be concave inwardly of the can (100). After the beading portion (122) is formed, the cap plate (800) and the second gasket (900) are assembled, and the crimping portion (124) is formed to prevent the cap plate (800) from coming off. The crimping portion (124) can be formed by bending the end of the side portion (120) inwardly of the can (100).

[0050] The can (100) may be provided with a metal such as steel, nickel-plated steel, steel alloy, aluminum, aluminum alloy, deep drawing cooling sheet (SPCE), or a laminate film or plastic material constituting the pouch. An electrode assembly (200) is accommodated inside the can (100) together with an electrolyte.

[0051] The electrode assembly (200) may include or be referred to as an electrode group, an electrode body, or a jelly roll. Referring to FIG. 2, the electrode assembly (200) may include a first electrode plate (210), a second electrode plate (220), and a separator (230).

[0052] The first electrode plate (210) may be either a negative electrode plate or a positive electrode plate. The first electrode plate may include a first substrate, which is a metal thin plate, a first active material layer provided on at least one surface of the first substrate, and a first non-conductive portion on which the first active material is not provided. The first non-conductive portion may be referred to as the first substrate.

[0053] For example, the first electrode plate may function as an anode. The first substrate may include aluminum foil, and the first active material layer may include a transition metal oxide.

[0054] In some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) may be used as the cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from the group consisting of cobalt, manganese, nickel, and combinations thereof may be used.

[0055] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0056] As an example, a compound represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaMn2-bXbO4-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNi1-b-cMnbXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNibCocL1dGeO2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); LiaNiGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-bGbO2 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-gGgPO4 (0.90=a=1.8, 0=g=0.5); Li(3-f)Fe2(PO4)3(0=f=2); LiaFePO4(0.90=a=1.8).

[0057] In the 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 L1 is Mn, Al, or a combination thereof.

[0058] A positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) 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.

[0059] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0060] Aluminum may be used as the current collector, but is not limited thereto.

[0061] The second electrode plate (220) may be the other of the negative electrode plate and the positive electrode plate. The second electrode plate may include a second substrate which is a metal sheet, a second active material layer provided on at least one surface of the second substrate, and a second non-conductive portion on which the second active material layer is not provided.

[0062] For example, the second electrode plate may function as a cathode. The second substrate may include copper or nickel foil, and the second active material layer may include a carbon-based material, Si, Sn, tin oxide, a tin alloy composite, a transition metal oxide, lithium metal nitrite, or a metal oxide.

[0063] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0064] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0065] As the material capable of doping and dedoping the 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 can be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0066] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0067] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0068] A negative electrode for a lithium secondary battery may include a current collector (e.g., a second substrate) and a negative electrode active material layer formed on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0069] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0070] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0071] The current collector may be 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.

[0072] A separator (230) is interposed between a first electrode plate (210) and a second electrode plate (220) and serves to prevent a short circuit between the first electrode plate (210) and the second electrode plate (220). For example, the separator (230) may include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0073] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0074] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0075] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0076] An electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0077] The non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move. 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.

[0078] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0079] For example, the electrode assembly (200) may be arranged so that the uncoated portion of the first electrode plate (210) protrudes upwardly from the upper end of the second electrode plate (220). In addition, the uncoated portion of the second electrode plate (220) may be arranged so as to protrude downwardly from the lower end of the first electrode plate (210) and may be wound in a jelly-roll shape. In this state, the first current collector plate (300) may be welded to the uncoated portion of the first electrode plate (210), and the second current collector plate (400) may be welded to the uncoated portion of the second electrode plate (220).

[0080] As illustrated in FIG. 2, the first collector plate (300) is disposed between the upper surface (122) and the non-conductive portion of the first electrode plate (210). The first collector plate (300) is electrically connected to the first electrode plate (210), which is a positive electrode plate, by welding, and thus may be defined as a positive collector plate. The first collector plate (300) may have an approximately circular shape. The first collector plate (300) may be electrically connected to the positive terminal (600) at the central portion. However, since the first collector plate (300) must be insulated from the can (100), an insulating tape (500) may be attached to the outer side of the first collector plate (300).

[0081] As illustrated in FIG. 2, the second collector plate (400) is positioned between the cap plate (800) and the non-conductive portion of the second electrode plate (220). The second collector plate (400) is electrically connected to the second electrode plate (220), which is the negative electrode plate, by welding, and thus can be defined as a negative collector plate. The second collector plate (400) may have an approximately circular shape. The second collector plate (400) may be electrically connected to the side portion (120) of the can (100) by a plurality of negative leads (450).

[0082] As illustrated in FIG. 2, the negative lead (450) may have a plate shape having a predetermined length and width. The negative lead (450) is a conductor and electrically connects the second collector plate (400) and the side (120) of the can (100). One end of the negative lead (450) is electrically connected to the second collector plate (400), and the other end may be inserted between the beading portion (122) and the second gasket (900) to be electrically connected to the side (120). For example, one end of the negative lead (450) and the second collector plate (400) may be welded, and the other end of the negative lead (450) may or may not be welded to the side (120). Since the negative lead (450) can be fixed without welding by the beading portion (122), the second gasket (900), and the crimping portion (124), welding between the side portion (120) and the negative lead (450) can be omitted. Since the second collector plate (400) and the negative lead (450) are electrically connected, and the negative lead (450) is electrically connected to the side portion (120), the can (100) has a negative polarity. Accordingly, the positive terminal (600) is installed so as to be insulated from the can (100). However, the second collector plate (400) may be directly welded to the side portion (120) without the aforementioned negative lead (450). Alternatively, the cap plate (800) may be directly connected to the second electrode plate (220) and electrically connected to the can (100) without the negative lead (450) and the second collector plate (400).

[0083] Referring to FIGS. 2 and 3, the insulating tape (500) is a circular plate with a hollow portion formed therein and is made of an insulating material. The remaining portion of the insulating tape (500), excluding the hollow portion, is provided to wrap the upper surface of the first collector plate (300) and the upper portion of the outer circumference of the electrode assembly (200). Therefore, the diameter of the insulating tape (500) may be formed to be larger than the diameter of the electrode assembly (200). The insulating tape (500) may be formed such that the surface facing the first collector plate (300) has adhesive properties. For example, an adhesive surface may or may not be formed in the area wrapping the upper portion of the outer circumference of the electrode assembly (200). The insulating tape (500) will be described in detail later. Through the hollow portion of the insulating tape (500), the lower portion of the positive terminal (600) and the first collector plate (300) may come into contact and be electrically connected.

[0084] As shown in FIGS. 1 and 2, the positive terminal (600) is installed to be insulated from the upper surface (110) of the can (100) by the first gasket (700). The positive terminal (600) has an upper portion exposed to the outside of the upper surface (110), and a lower portion in contact with the first collector plate (300) to be electrically connected. For example, the positive terminal (600) is a rivet terminal that is riveted to the upper surface (110) from the inside or outside of the can (100). The positive terminal (600)

[0085] As illustrated in FIGS. 1 and 2, the first gasket (700) insulates between the positive terminal (600) and the can (100). For example, the first gasket (700) may include an upper gasket (710) that insulates between the positive terminal (600) and the outer surface of the upper surface (110), and a lower gasket (720) that insulates between the positive terminal (600) and the inner surface of the upper surface (110). Alternatively, the upper gasket (710) and the lower gasket (720) may be formed integrally. The aforementioned insulating tape (500) may be provided between the lower gasket (720) and the first collector plate (300).

[0086] Referring to Fig. 2, the cap plate (800) has a roughly circular shape and can be joined to the side (120) via a second gasket (900). The cap plate (800) can be fixed to the can (100) by a beading portion (122) and a crimping portion (124). Since the second gasket (900) is placed between the cap plate (800) and the side (120), the cap plate (800) is insulated from the can (100). Therefore, the cap plate (800) becomes neutral, not exhibiting a negative or positive polarity. A notch (810) that serves as a safety vent for gas discharge can be formed on the surface of the cap plate (800).

[0087] Below, various embodiments of the aforementioned insulating tape (500) are described in detail.

[0088] Figures 4a to 4d are plan views illustrating the shape of cut portions of insulating tapes according to embodiments of the present invention. Figures 5a to 5e are plan views illustrating the number of cut portions of insulating tapes according to embodiments of the present invention.

[0089] Referring to FIGS. 3 and 4A, the insulating tape (500) may be provided with a plurality of cut portions along the circumferential direction. One cut portion may include a cut line (510) cut in a straight line, and a cut hole (520) cut in a preset shape connected to the cut line (510). For example, the cut hole (520) may be circular. For example, the diameter of the cut hole (520) may be 10% to 40% of the length of the cut line (510). Even if the diameter of the cut hole (520) increases to the maximum, it should not overlap with an adjacent cut hole (520). The cut hole (520) is arranged closer to the center of the insulating tape (500) than the cut line (510). That is, the cut hole (520) is arranged so as to face the center of the insulating tape (500). This is to prevent the substrate (non-conductive part) of the electrode assembly (200) from being exposed through the cut hole (520).

[0090] When attaching an insulating tape (500) to an electrode assembly (200), a problem occurs in that the insulating tape (500) wrapping the side portion folds or wrinkles, thereby increasing the major diameter of the electrode assembly (200). In order to minimize the increase in thickness of the side portion, a straight cut line can be formed in the outer circumference of the insulating tape (500). However, the straight cut line has a problem in that it is easily torn during the attachment process. If the insulating tape (500) is torn, there is a risk that the electrode assembly (200) and the can (100) may come into contact, resulting in a short circuit. Therefore, it is necessary to increase the tensile strength of the insulating tape (500) to prevent tearing. To this end, a circular cut hole (520) is provided in addition to the straight cut line (510). When a cut hole (520) is provided, compared to when only a straight cut line (510) is provided, even if force is applied to the cut line (510), the force can be distributed in various directions (see Fig. 4a). Accordingly, the tensile strength of the cut area of ​​the insulating tape (500) increases, thereby preventing tearing of the insulating tape (500).

[0091] The cutting hole (520) may be provided in various shapes. A circular cutting hole (520) as in FIG. 4a, a vertically elongated oval cutting hole (520a) as in FIG. 4b may be provided. Alternatively, a horizontally elongated oval cutting hole (520b) as in FIG. 4c, or a triangular (or polygonal) cutting hole (520c) as in FIG. 4d may be provided. When the cutting hole (520) has a shape other than a circle, the longitudinal length may be set to a maximum of 70% of the length of the cutting lines (510a, 510b, 510c).

[0092] In addition, the number of cuts may be odd. For example, 11 cuts may be arranged. Referring to FIG. 5A, with reference to the reference line B passing through the center of the insulating tape (500), a cut is arranged in the area C that overlaps the reference line B. However, if the number of cuts is odd, no cut is arranged in the area D. This remains the same even if the position of the reference line B is changed. If the number of cuts is even, the cuts are located in both areas C and D with an arbitrary reference line as the center. Therefore, when the insulating tape (500) is attached to the electrode assembly (200), the insulating tape (500) overlaps in both areas C and D, thereby increasing the thickness. However, if the number of cuts is odd, the insulating tape (500) overlaps only in one area (area C or area D) with an arbitrary reference line as the center. Therefore, the increase in the outer diameter of the electrode assembly (200) due to overlapping of the insulating tape (500) can be minimized.

[0093] Referring to Fig. 5b, the insulating tape (500) having 13 cuts also has cuts that overlap the reference line only in area C. That is, no cuts are placed in area D.

[0094] Referring to Fig. 5c, the insulating tape (500) having 15 cuts is also arranged so that the cuts overlap the reference line only in area C. That is, no cuts are arranged in area D.

[0095] Referring to FIG. 5d, the insulating tape (500) having 17 cuts is also arranged so that the cuts overlap the reference line only in area C. That is, no cuts are arranged in area D.

[0096] Referring to Fig. 5e, the insulating tape (500) having 19 cuts is also arranged so that the cuts overlap the reference line only in area C. That is, no cuts are arranged in area D.

[0097] As described above, when the number of cuts is odd, the diameter of the electrode assembly (200) is reduced compared to when the number of cuts is even. When inserting the electrode assembly (200) into the can (100), the free fall time of the electrode assembly (200) inserted into the can (100) may also be reduced due to the reduction in the diameter. As a result of the drop time test of the electrode assembly (200), the drop time of the electrode assembly (200) is reduced as follows depending on the number of cuts.

[0098] Below, the assembly process of the electrode assembly and can is briefly described.

[0099] FIG. 6 is a drawing illustrating an assembly process of an electrode assembly and a can according to one embodiment of the present invention.

[0100] As shown in FIGS. 3 and 4, after winding the electrode assembly (200), the first collector plate (300) is attached, and an insulating tape (500) is attached on the first collector plate (300) of the electrode assembly (200). At this time, the positive electrode side of the electrode assembly (200) may or may not have the insulating tape (500) attached.

[0101] Thereafter, as illustrated in FIG. 6, the upper surface (110) of the can (100) is placed so that the lower surface thereof is directed downward, and the upper portion of the electrode assembly (200) is directed toward the can (100). Then, when the electrode assembly (200) is inserted into the can (100), the insulating tape (500) is inserted into the can (100) while naturally wrapping around the outer side of the electrode assembly (200). Therefore, the outer end of the electrode assembly (200) and the can (100) can be insulated by the insulating tape (500). That is, the insulating tape can be inserted together with the insertion process of the electrode assembly without a separate insulating tape attachment process. However, it is also acceptable to insert the electrode assembly (200) into the can (100) with the insulating tape (500) completely attached to the can.

[0102] The secondary battery according to the above-described embodiment can be used to manufacture a battery pack (reference numbers of the components described below are reference numbers that apply only to the corresponding drawing).

[0103] FIGS. 11 and 12 are perspective views illustrating a battery pack (300) including an exemplary cylindrical secondary battery according to the present invention. Referring to FIGS. 11 and 12 , the battery pack (300) may include a plurality of battery modules (200) and a housing (310) for accommodating the plurality of battery modules (200). For example, the housing (310) may include first and second housings (311, 312) that are coupled in a direction facing each other with the plurality of battery modules (200) interposed therebetween. The plurality of battery modules (210) may be electrically connected to each other using a bus bar (251), and the plurality of battery modules (200) may be electrically connected to each other in a series / parallel or series-parallel hybrid manner to obtain a required electrical output. In the drawings, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrically connecting battery cells are omitted. In some examples, the battery pack (300) may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0104] Figures 13 and 14 are perspective views and side views illustrating a vehicle (400, 500) including an exemplary battery pack (300) according to the present invention. In Figure 13, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is a part of a vehicle underbody (410) and a pack frame (312) (which may correspond to the second housing) which is disposed at a lower portion of the vehicle underbody (410). The battery pack cover (311) and the pack frame (312) may be formed integrally with the vehicle floor (420). The vehicle underbody (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed at the exterior of the vehicle.

[0105] As illustrated in FIG. 14, a vehicle (500) may be formed by combining additional components, such as a hood (510) at the front of the vehicle and fenders (520) positioned at the front and rear of the vehicle, respectively, with a body (400). The vehicle (500) includes a battery pack (300) including a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with a body component (400).

[0106] The above description is only one embodiment for carrying out the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, it will be said that the technical spirit of the present invention exists to the extent that anyone with ordinary skill in the art to which the present invention pertains can make various modifications without departing from the gist of the present invention.

Claims

1. An electrode assembly having a first electrode plate and a second electrode plate; A cylindrical can accommodating the electrode assembly; A positive terminal connected to one end of the above can; A first collector plate disposed between the first electrode plate and the positive electrode terminal and electrically connected to the first electrode plate and the positive electrode terminal; A second current collector plate electrically connected to the second electrode plate and the can; a cap plate coupled to the other end of the can; and A secondary battery comprising an insulating tape disposed between one end of the can and the first collector plate, covering the first collector plate, and having a plurality of cutouts.

2. In paragraph 1, The above insulating tape is a circular secondary battery with a hollow shape.

3. In paragraph 2, A secondary battery, wherein the insulating tape has a diameter larger than the diameter of the electrode assembly.

4. In paragraph 3, A secondary battery, wherein the above-mentioned cut portion is arranged along the outer circumferential direction.

5. In paragraph 4, A secondary battery, wherein the above-mentioned cut portion includes a cut line cut in a straight line shape and a cut hole cut in a preset shape.

6. In paragraph 5, A secondary battery in which the above-mentioned cutting line and the above-mentioned cutting hole are connected to each other.

7. In paragraph 6, The above-mentioned cut hole is one of a circle, an ellipse, and a polygon, and is a secondary battery.

8. In paragraph 6, A secondary battery, wherein the above cut portions are provided in an odd number.

9. In paragraph 6, A secondary battery, wherein the above-mentioned cut portions are provided in an odd number between 11 and 19.

10. In paragraph 1, A secondary battery, wherein the surface of the insulating tape facing the first collector plate is an adhesive surface.

11. In paragraph 1, A secondary battery, wherein the can has a top surface in the shape of a disc and a side surface extending from the top surface, the positive terminal is coupled to the top surface, and the cap plate is coupled to an end of the side surface.

12. In paragraph 10, A secondary battery further comprising a first gasket insulating between the positive terminal and the upper surface, and a second gasket insulating between the cap plate and the side.

13. In paragraph 12, A secondary battery, wherein the side portion includes a beading portion formed concavely toward the inside, and a crimping portion formed by bending an end of the side portion while the cap plate is coupled.

14. In paragraph 13, A secondary battery, wherein the second gasket is inserted between the beading portion and the crimping portion.

15. In paragraph 14, A secondary battery further comprising a plurality of negative leads electrically connecting the second collector plate to the side portion.

16. In paragraph 15, A secondary battery, wherein one end of the negative lead is connected to the second collector plate and the other end is inserted between the beading portion and the second gasket.

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