Insulating tape, jelly roll, secondary battery, battery pack, and automobile

Abstract

The present invention provides a jelly roll comprising: an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are stacked and wound; and an insulating tape provided to cover at least a portion of a side surface of the electrode assembly and at least a portion of an end of the electrode assembly, the insulating tape having at least one notch pattern provided in an area covering at least a portion of the end of the electrode assembly, and a secondary battery, a battery module, and a battery pack including the same.

Description

Technical Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0160779, filed with the Korean Intellectual Property Office on November 19, 2021, and all of the content disclosed in the document of the Korean patent application is incorporated herein by reference.

[0002] The present invention relates to an insulating tape, a jelly roll, a secondary battery, a battery pack, and a vehicle.

Background Art

[0003] Secondary batteries, which are highly applicable to a group of products and have electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source.

[0004] Such secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement because they not only have the primary advantage of significantly reducing the use of fossil fuels but also have the advantage of generating no by-products from energy use.

[0005] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a plurality of battery cells are connected in series to form a battery pack. Also, depending on the charge and discharge capacity required for the battery pack, a large number of battery cells are connected in parallel to form a battery pack. Therefore, the number and electrical connection form of the battery cells included in the battery pack can be variously set according to the required output voltage and / or charge and discharge capacity.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a jelly roll capable of realizing a high energy density and a secondary battery.

[0007] Another object of the present invention is to provide an insulating tape for realizing the jelly roll as described above.

Means for Solving the Problems

[0008] One embodiment of the present invention includes an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound; and an insulating tape provided so as to cover at least a part of a side surface of the electrode assembly and at least a part of an end portion of the electrode assembly. The insulating tape has at least one notch pattern provided in a region covering at least a part of an end portion of the electrode assembly, and provides a jelly roll.

[0009] Another embodiment of the present invention is an insulating tape for adhering so as to cover at least a part of a side surface of an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound and at least a part of an end portion of the electrode assembly, and has at least one notch pattern at at least one end, and provides an insulating tape.

[0010] Another embodiment of the present invention provides a secondary battery including the jelly roll according to the above-described embodiment.

Advantages of the Invention

[0011] When using a conventional insulating tape to entirely cover the side and end portions of an electrode assembly, a portion where the insulating tapes overlap occurs at the end portion perpendicular to the winding axis of the electrode assembly. As a result, a step is generated, and a lifting phenomenon inevitably occurs between the components located on the end portion side of the electrode assembly. When the lifting phenomenon occurs, there is a possibility that a defect may occur in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0012] According to an embodiment of the present invention, by minimizing or preferably eliminating the region where the insulating tapes overlap at the end portion of the electrode assembly, it is possible to prevent the lifting problem that creates a space between other components provided on the end portion side of the electrode assembly, such as an additional insulating member or a current collector plate and the end portion of the electrode assembly. As a result, it is possible to prevent a defect in the electrical connection between the electrode tab portion and the electrode terminal portion. Further, when welding the electrode tab portion to the electrode terminal portion directly or via a current collector plate for electrical connection, it is possible to prevent the occurrence of welding defects.

[0013] As described above, by solving the lifting problem at the end portion of the electrode assembly, the tab structure of the electrode included in the electrode assembly is formed in a plain portion on the current collector without coating the electrode active material, so that the current applied to the battery can be increased. As a result, the size of the battery can be increased, enabling the realization of a high energy density and cost savings.

Brief Description of the Drawings

[0014]

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Figure 16

Mode for Carrying Out the Invention

[0015] The terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings. Instead, in accordance with the principle that the inventor can appropriately define the concept of the terms in order to best explain his or her invention, they should be construed in a meaning and concept that conforms to the technical idea of the present invention.

[0016] Throughout this specification, when a part "includes" a certain component, this means that, unless otherwise stated to the contrary, it can further include other components rather than excluding other components.

[0017] Also, terms such as "… part" and "device" described in the specification mean a unit that processes at least one function or operation. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0018] One embodiment of the present invention provides a jelly roll including: an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound; and an insulating tape provided so as to cover at least a part of the side surface and at least a part of the end portion of the electrode assembly, wherein the insulating tape has at least one notch pattern provided in a region covering at least a part of the end portion of the electrode assembly.

[0019] The notch pattern of the insulating tape means a pattern in which a groove is formed by being cut from the edge of the insulating tape.

[0020] The end of the electrode assembly means the end in the direction perpendicular to the winding axis of the electrode assembly, and the side surface of the electrode assembly means the surface among the outer surfaces of the electrode assembly that is horizontal to the winding axis. By the notch pattern of the insulating tape, the area where the insulating tapes overlap with each other can be minimized in the region covering at least a part of the end of the electrode assembly. Therefore, the phenomenon of lifting at the end of the electrode assembly can be prevented, and the electrode assembly can be compactly packed in the battery can. Also, due to the characteristics of the battery, the phenomenon of lifting at the end of the electrode assembly can be prevented, and poor electrical connection between the electrode tab portion and the electrode terminal portion can be prevented. As a result, the resistance can be reduced and a high energy density can be maintained.

[0021] The electrode tab portion may be the first electrode tab portion or the positive electrode tab portion of the electrode assembly, that is, the first electrode non-coated portion or the positive electrode non-coated portion. The electrode terminal portion may be the first electrode terminal portion or the positive electrode terminal portion.

[0022] According to an embodiment of the present invention, in the entire area covering the end of the electrode assembly, the area where the insulating tapes overlap with each other is 10% or less.

[0023] In the entire area covering the end of the electrode assembly, the area where the insulating tapes overlap with each other may be 9% or less, 8% or less, or 7% or less. More preferably, there may be a case where the insulating tapes do not overlap with each other in the region covering the end of the electrode assembly.

[0024] FIG. 1 is a photograph comparing the case where an insulating tape without a notch pattern is attached (left side) and the case where an insulating tape with a notch pattern is attached (right side) at the end of the electrode assembly. In the left photograph, the overlapping portion of the insulating tape (indicated by a circle) is observed, but in the right photograph, no overlapping of the insulating tape occurs.

[0025] Figure 2 is a photograph comparing the case where an insulating tape without a notch pattern is attached (left side) and the case where an insulating tape with a notch pattern is attached (right side) from the side of the electrode assembly. In the photograph on the left, a step (indicated by a circle) is observed due to the overlapping part of the insulating tape, while in the photograph on the right, no step is generated due to the overlapping of the insulating tape.

[0026] According to an embodiment of the present invention, the insulating tape has two or more notch patterns, and the flag shape provided between two adjacent notch patterns may be at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semi - circle.

[0027] The flag shape may be provided in a region where the insulating tape extends on the side surface of the electrode assembly and covers the end portion of the electrode assembly. These flag shapes are advantageous for preventing them from overlapping each other at the end portion of the electrode assembly. The flag shape is not limited to this, and any shape that can prevent them from overlapping each other at the end portion of the electrode assembly may be adopted in an embodiment of the present invention.

[0028] According to an embodiment of the present invention, the shape of the notch pattern of the insulating tape is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semi - circle.

[0029] The shape of the notch pattern is not limited to this, and any shape that can prevent the insulating tapes from overlapping each other at the end portion of the electrode assembly may be adopted in an embodiment of the present invention.

[0030] Figure 4 is a drawing showing the notch pattern shape of the insulating tape and the state after the insulating tape is attached according to an embodiment of the present invention.

[0031] As an example, the notch pattern shape 130 is trapezoidal, the flag shape 140 is triangular, and the shape of the insulating tape provided at the end of the electrode assembly is triangular (upper). As another example, the shape of the notch pattern 130 is trapezoidal, the flag shape 140 is trapezoidal, and the shape of the insulating tape 120 provided at the end of the electrode assembly is trapezoidal (lower).

[0032] According to an embodiment of the present invention, at least one of the first electrode and the second electrode includes a current collector and an electrode active material layer provided on the current collector. The current collector includes a plain portion without the electrode active material layer, and at least a part of the plain portion is exposed on the side surface of the electrode assembly. The insulating tape is provided to cover the plain portion on the side surface of the electrode assembly.

[0033] At least a part of the plain portion provided on the side surface of the electrode assembly may be used as an electrode tab by itself.

[0034] By providing the insulating tape to cover the plain portion, electrical contact with the battery can be prevented. The notch pattern of the insulating tape can prevent the lifting phenomenon at the end of the electrode assembly and prevent defects in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0035] According to an embodiment of the present invention, the insulating tape is provided to cover 5% to 60% of the first electrode or the second electrode exposed at the end of the electrode assembly.

[0036] According to an embodiment of the present invention, at least a part of the plain portion is exposed at the end of the electrode assembly, and the insulating tape is provided to cover 5% to 60% of the plain portion at the end of the electrode assembly.

[0037] The first electrode or the second electrode may be exposed at the end of the electrode assembly. Specifically, at least a part of the plain portion without the electrode active material layer on the first electrode or the second electrode may be exposed.

[0038] At least a part of the plain portion provided at the end of the electrode assembly body may be used as an electrode tab by itself, and as will be described later, it may further include a current collector plate provided on the end side of the electrode assembly body and be electrically connected.

[0039] Thereby, at least a part of the plain portion of the first electrode or the second electrode and / or the current collector plate connected thereto can be exposed at the end of the electrode assembly body.

[0040] The fact that the insulating tape is provided to cover 5% to 60% of the first electrode or the second electrode, or the plain portion at the end of the electrode assembly body may mean covering 5% to 60% of the first electrode or the second electrode, or the plain portion exposed from the outer peripheral surface at the end of the electrode assembly body.

[0041] The insulating tape may be provided to cover 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more of the first electrode or the second electrode, or the plain portion at the end of the electrode assembly body.

[0042] The insulating tape may be provided to cover 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, or 35% or less of the first electrode or the second electrode, or the plain portion at the end of the electrode assembly body.

[0043] By providing the insulating tape to cover 5% to 60% of the first electrode or the second electrode, the plain portion of the first electrode or the second electrode, and / or the current collector plate connected thereto, electrical contact with the battery can be prevented. The notch pattern of the insulating tape can prevent the lifting phenomenon at the end of the electrode assembly body, and prevent defects in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0044] According to one embodiment of the present invention, the thickness of the insulating tape is 10um to 100um.

[0045] The thickness of the insulating tape may be 10um or more, 13um or more, 15um or more, or 17um or more. The thickness of the insulating tape may be 100um or less, 90um or less, 80um or less, 70um or less, 60um or less, 50um or less, 40um or less, or 30um or less.

[0046] When the above range is satisfied, the insulating tape can cover the plain part to prevent electrical contact with the battery can, prevent the lifting phenomenon at the end of the electrode assembly, and prevent defects in the electrical connection between the electrode tab part and the electrode terminal part.

[0047] According to one embodiment of the present invention, the insulating tape includes a fabric and an adhesive layer, the thickness of the fabric is 3um to 25um, and the thickness of the adhesive layer is 2um to 20um.

[0048] The insulating tape may include a fabric and an adhesive layer, and the thickness of the insulating tape including the fabric and the adhesive layer may be 15um or more, 20um or more, 25um or more, or 30um or more. The thickness of the insulating tape including the fabric and the adhesive layer may be 90um or less, 80um or less, 70um or less, or 60um or less.

[0049] The thickness of the fabric of the insulating tape may be 5um or more, 7um or more, 9um or more, or 11um or more. The thickness of the fabric of the insulating tape may be 23um or less, 21um or less, 19um or less, or 17um or less.

[0050] The thickness of the adhesive layer of the insulating tape may be 4um or more, 6um or more, 8um or more, or 10um or more. The thickness of the adhesive layer of the insulating tape may be 18um or less, 16um or less, 14um or less, or 12um or less.

[0051] When the above range is satisfied, the insulating tape having the notch pattern at the end of the electrode assembly can be better adhered. Specifically, the thinner the thickness of the fabric of the insulating tape, the more advantageous it may be, and the thicker the thickness of the adhesive layer of the insulating tape, the better it can be adhered at the end of the electrode assembly.

[0052] In particular, the insulating tape may have a fabric thickness reduced by about 50% and an adhesive layer thickness increased by about 150% compared to the conventional case. Within the above range, the insulating tape may be advantageous for adhesion at the end of the electrode assembly because the fabric thickness of the insulating tape is thinner and the adhesive layer thickness of the insulating tape is thicker compared to the conventional case.

[0053] According to an embodiment of the present invention, the insulating tape includes one or more selected from the group consisting of polyimide, polyethylene, polypropylene, polytetrafluoroethylene, polyethylene terephthalate, and polybutylene terephthalate. In addition, the material of the insulating tape is not particularly limited as long as it is an insulating material that does not exude, swell, or cause side reactions by the electrolytic solution.

[0054] According to an embodiment of the present invention, it further includes a current collector plate provided on the end side of the electrode assembly. The insulating tape is in a region covering the end of the electrode assembly. The current collector plate may be located between the insulating tape and the electrode assembly, or the current collector plate may be located on the other end side which is the opposite surface of the surface where the electrode assembly faces the insulating tape.

[0055] Among the current collectors provided on the end side of the electrode assembly, the current collector positioned between the insulating tape and the electrode assembly may be a first current collector, and the current collector positioned at the other end, which is the opposite surface of the surface of the electrode assembly facing the insulating tape, may be a second current collector.

[0056] Specifically, the first current collector may be electrically connected to the plain portion and may also be electrically connected to the electrode terminal on the opposite surface. At this time, by providing an insulating tape with a notch pattern, it is possible to prevent the lifting phenomenon at the end of the electrode assembly, facilitate the electrical connection of the electrode terminal portion, and prevent the occurrence of welding defects.

[0057] According to an embodiment of the present invention, an insulating member may be further included on the end side of the electrode assembly so as to cover at least a part of the end of the electrode assembly or at least a part of the end of the electrode assembly and at least a part of the side surface of the electrode assembly.

[0058] The insulating member may be an insulator, and the insulator can block the electrical contact between the jelly roll electrode tab portion and the battery can to prevent the short circuit of the electrode.

[0059] When the insulating tape having the notch pattern is attached, the region where the insulating tape is superimposed at the end of the electrode assembly can be minimized, the distance from the insulating member can be reduced, and the poor electrical connection between the electrode tab portion and the electrode terminal portion can be prevented.

[0060] Figure 3 compares the presence or absence of the lifting phenomenon when an additional insulating member is positioned on the upper surface of the electrode assembly when an insulating tape without a notch pattern is attached (left side) and when an insulating tape with a notch pattern is attached (right side).

[0061] The lifting phenomenon of the insulating member when the insulating tape without the notch pattern is attached appeared more significantly than when the insulating tape with the notch pattern is attached.

[0062] FIG. 7 is a longitudinal sectional view showing a schematic configuration of a secondary battery according to an embodiment of the present invention, and (a) is a drawing showing a case including a "⊂"-shaped insulating member, and (b) is a drawing showing a case including a "-"-shaped insulating member.

[0063] Referring to FIG. 7(a), according to an embodiment, the insulating member 60 may be provided to cover at least a part of an end portion and at least a part of a side surface of the electrode assembly, and the insulating member 60 may be, for example, a "⊂"-shaped insulating member.

[0064] Referring to FIG. 7(b), according to another embodiment, the insulating member 60 may be provided to cover at least a part of an end portion of the electrode assembly on an end side of the electrode assembly, and the insulating member 60 may be, for example, a "-"-shaped insulating member.

[0065] When the insulating tape 100 having the notch pattern is attached in the case of including the insulating member 60, the region where the insulating tape is superimposed at the end of the electrode assembly can be minimized, the distance from the insulating member 60 can be reduced, the floating phenomenon between the electrode tab portion and the electrode terminal portion can be prevented, and the poor electrical connection can be prevented.

[0066] Another embodiment of the present invention is an insulating tape for attaching to cover at least a part of a side surface and at least a part of an end portion of an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound, the insulating tape having at least one notch pattern on at least one edge portion.

[0067] According to another embodiment of the present invention, the insulating tape has two or more notch patterns, and the flag shape provided between two adjacent notch patterns is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semicircle, and the shape of the notch pattern of the insulating tape is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semicircle.

[0068] Here, regarding the shape, thickness, material of the insulating tape, and the structure of the notch pattern, etc., the description given for the above jelly roll may be applicable.

[0069] Another embodiment of the present invention provides a secondary battery including: a jelly roll according to the above-described embodiment; a battery can having an opening on one side for housing the jelly roll; an electrode terminal riveted through a through-hole formed in the bottom of the battery can; a gasket provided between the electrode terminal and the outer diameter of the through-hole; and a sealing body for sealing the opening of the battery can.

[0070] According to another embodiment of the present invention, the first electrode is electrically connected to the electrode terminal, the second electrode is electrically connected to the battery can, and the sealing body is insulatable from the battery can.

[0071] Here, regarding the shape, thickness, material of the insulating tape included in the jelly roll included in the secondary battery, and the structure of the notch pattern, etc., the description given for the above jelly roll may be applicable.

[0072] According to one embodiment, the first electrode may be a positive electrode and the second electrode may be a negative electrode.

[0073] FIG. 5 is a drawing showing a schematic configuration of a secondary battery according to an embodiment of the present invention, FIG. 6 is a longitudinal sectional view of the secondary battery of FIG. 5, and FIG. 8 is a drawing showing a schematic configuration of an electrode assembly included in the secondary battery of FIG. 5.

[0074] Referring to FIGS. 5, 6, and 8, a secondary battery 1 according to an embodiment of the present invention includes an electrode assembly 10, a battery can 20, a sealing body 30, and an electrode terminal 40. The jelly roll may include the electrode assembly 10. The secondary battery 1 may further include, in addition to the above-described components, a first current collector 50 and / or an insulating member 60 and / or a gasket 70 and / or a second current collector 80 and / or a sealing gasket 90.

[0075] Referring to FIGS. 5, 6, and 8, the electrode assembly 10 includes a first electrode 11 as a positive electrode, a second electrode 12 as a negative electrode, and a separator 13 interposed between the first electrode 11 and the second electrode 12. The first electrode 11 and the second electrode 12 may have a sheet shape. The electrode assembly 10 may have, for example, a jellyroll shape. That is, the electrode assembly 10 can be manufactured by winding a laminate formed by sequentially laminating at least once the first electrode 11, the separator 13, the second electrode 12, and the separator 13 around a winding center C. In this case, a separator 13 may be further provided on the outer peripheral surface of the electrode assembly 10 for insulation from the battery can 20.

[0076] The first electrode 11 and the second electrode 12 may include plain portions 11a and 12a where the active material layer is not coated at the long side ends. The first electrode 11 and the second electrode 12 may include active material portions 11b and 12b where the active material layer is coated in the regions excluding the plain portions 11a and 12a.

[0077] Specifically, the first electrode 11 includes a first current collector and a first electrode active material coated on one or both surfaces of the first current collector. The region where the first electrode active material is coated on the first current collector is referred to as the active material portion 11b provided in the first electrode 11. A plain portion 11a where the first electrode active material is not coated may exist at one end portion in the width direction (the direction aligned with the Z axis) of the first current collector. At least a part of the plain portion 11a is used as an electrode tab by itself. That is, the plain portion 11a functions as the plain portion 11a provided in the first electrode 11. The plain portion 11a provided in the first electrode 11 is provided at the upper part in the height direction (the direction aligned with the Z axis) of the electrode assembly 10 housed in the battery can 20. An insulating layer may be additionally provided at the boundary between the plain portion 11a and the active material portion 11b provided in the first electrode 11. The insulating layer has the effect of preventing short - circuit of the electrodes even when the separator shrinks.

[0078] The second electrode 12 includes a second electrode current collector and a second electrode active material coated on one or both surfaces of the second electrode current collector. A region where the second electrode active material is coated on the second electrode current collector is referred to as an active material portion 12b provided in the second electrode 12. There may be a plain portion 12a on the other end of the second electrode current collector in the width direction (the direction aligned with the Z-axis) where the second electrode active material is not coated. At least a part of the plain portion 12a is used as an electrode tab by itself. That is, the plain portion 12a functions as the plain portion 12a provided in the second electrode 12. The plain portion 12a provided in the second electrode 12 is provided at the lower part in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10 housed in the battery can 20.

[0079] The plain portion 11a provided in the first electrode 11 and the plain portion 12a provided in the second electrode 12 may be in a form protruding in opposite directions. For example, referring to FIG. 8, the plain portion 11a provided in the first electrode 11 may protrude upward in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10, and the plain portion 12a provided in the second electrode 12 may protrude downward in the height direction (the direction aligned with the Z-axis) of the electrode assembly 10. Thereby, the plain portion 11a provided in the first electrode and the plain portion 12a provided in the second electrode may be in a form extending and protruding in opposite directions along the width direction of the electrode assembly 10, that is, the height direction (the direction aligned with the Z-axis) of the secondary battery 1.

[0080] According to one embodiment, the first electrode may be a positive electrode and the second electrode may be a negative electrode.

[0081] In one example of the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be used without limitation as long as they are active materials known in the art.

[0082] As non-limiting examples of the positive electrode active material, ordinary positive electrode active materials that can be used for the positive electrode of conventional electrochemical elements can be used. In particular, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a lithium composite oxide combining these may be used.

[0083] In one example, the positive electrode active material may contain an alkali metal compound represented by the general chemical formula A[A x M y O 2+z (A contains at least one or more elements of Li, Na, and K; M contains at least one or more elements selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≧0, 1≦x + y≦2, -0.1≦z≦2; the stoichiometric coefficients of x, y, z, and the components contained in M are selected so that the compound maintains electrical neutrality).

[0084] In another example, the positive electrode active material may be an alkali metal compound xLiM 1 O2-(1 - x)Li2M 2 O3 (M 1 contains at least one or more elements having an average oxidation state of 3; M 2 contains at least one or more elements having an average oxidation state of 4; 0≦x≦1).

[0085] In still another example, the positive electrode active material has the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z (M 1 contains at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2contains at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 contains a halogen group element selectively containing F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; a, x, y, z, M 1 、M 2 、and M 3 The stoichiometric coefficients of the components contained in and M are selected so that the compound maintains electrical neutrality), or it may be a lithium metal phosphate represented by Li3M2(PO4)3 [M contains at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0086] Preferably, the positive electrode active material may contain primary particles and / or secondary particles in which the primary particles are aggregated.

[0087] As a non-limiting example of the negative electrode active material, ordinary negative electrode active materials that can be used for the negative electrode of conventional electrochemical elements can be used. In particular, lithium metal or lithium alloys, carbon, petroleum coke, activated carbon, graphite or other carbonaceous materials such as lithium adsorbing substances can be used.

[0088] In one example, the negative electrode active material may be made of a carbon material, lithium metal or lithium metal compound, silicon or silicon compound, tin or tin compound, etc. Metal oxides such as TiO2 and SnO2 with a potential of less than 2V can also be used as the negative electrode active material. As the carbon material, any of low-crystalline carbon and highly crystalline carbon can be used.

[0089] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as a homopolymer of ethylene, a homopolymer of propylene, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, used alone or laminated. As another example, the separator may be an ordinary porous nonwoven fabric, for example, a nonwoven fabric made of high melting point glass fibers, polyethylene terephthalate fibers, etc.

[0090] The surface of at least one side of the separator may include a coating layer of inorganic particles. Also, the separator itself may consist of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bonded to a binder so that an interstitial volume exists between adjacent particles.

[0091] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles may include at least one or more substances selected from the group consisting of Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0092] The electrolyte may be a salt having a structure such as A + B - . Here, A + includes ions composed of alkali metal cations such as Li + , Na + , K + and combinations thereof. And B - is F - , Cl - , Br - , I - , NO3- , N(CN) 2- , BF4 - , ClO4 - , AlO4 - , AlCl4 - , PF6 - , SbF6 - , AsF6 - , BF2C2O4 - , BC4O8 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , CF3SO3 - , C4F9SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N - and contains any one or more anions selected from the group consisting of

[0093] The electrolyte may also be used after being dissolved in an organic solvent. Examples of the organic solvent include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0094] Referring to FIGS. 5 and 6, the battery can 20 is a substantially cylindrical container having an opening formed at the lower end, and is made of a material having conductivity such as, for example, metal. The material of the battery can 20 may be, for example, aluminum. The bottom of the battery can 20 having the opening is referred to as an opened end. The side surface (outer peripheral surface) and the upper surface of the battery can 20 may be integrally formed. The upper surface of the battery can 20 (the surface arranged in the X-Y plane) has a substantially flat shape. The upper surface located on the opposite side of the opened end is referred to as a closed end. The battery can 20 houses the electrode assembly 10 through the opening formed below, and also houses the electrolyte together.

[0095] The battery can 20 is electrically connected to the electrode assembly 10. The battery can 20 may be electrically connected to one of the first electrode 11 and the second electrode 12. For example, the battery can may be electrically connected to the second electrode 12 of the electrode assembly 10. In this case, the battery can 20 can have the same potential as the second electrode 12.

[0096] Referring to FIG. 6, the battery can 20 may include a beading portion 21 and a caulking portion 22 formed at its lower end. The beading portion 21 is located below the electrode assembly 10. The beading portion 21 is formed by press-fitting around the outer peripheral surface of the battery can 20. The beading portion 21 can function as a support portion on which the sealing body 30 is seated, so that the electrode assembly 10 having a size substantially corresponding to the width of the battery can 20 does not slip out through the open portion formed at the lower end of the battery can 20.

[0097] The caulking portion 22 is formed below the beading portion 21. The caulking portion 22 has a form that extends and bends so as to surround the outer peripheral surface of the sealing body 30 disposed below the beading portion 21 and a part of the lower surface of the sealing body 30.

[0098] However, the present invention does not exclude the case where the battery can 20 does not include such a beading portion 21 and / or caulking portion 22. That is, in one embodiment of the present invention, when the battery can 20 does not include the beading portion 21 and / or caulking portion 22, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be realized, for example, by additionally applying a component that can function as a stopper for the electrode assembly 10. Further, when the secondary battery 1 according to one embodiment of the present invention includes the sealing body 30, the fixing of the electrode assembly 10 and / or the sealing of the battery can 20 can be realized, for example, by additionally applying a structure on which the sealing body 30 can be seated and / or welding between the battery can 20 and the sealing body 30. That is, the sealing body can seal the open end of the battery can.

[0099] Referring to FIG. 6, the sealing body 30 may be made of, for example, a metal material in order to ensure rigidity. The sealing body 30 can cover the open end formed at the lower end of the battery can 20. That is, the sealing body 30 forms the lower surface of the secondary battery 1.

[0100] In the secondary battery 1 according to an embodiment of the present invention, even when the sealing body 30 is made of a conductive metal material, it has no polarity. Having no polarity may mean that the sealing body 30 is electrically insulated from the battery can 20 and the electrode terminal 40.

[0101] Therefore, the sealing body 30 does not function as the electrode terminal 40, that is, the positive electrode terminal or the negative electrode terminal. Thus, the sealing body 30 does not need to be electrically connected to the electrode assembly 10 and the battery can 20, and its material does not necessarily have to be a conductive metal.

[0102] When the battery can 20 according to an embodiment of the present invention includes the beading portion 21, the sealing body 30 may be seated on the beading portion 21 formed on the battery can 20. Further, when the battery can 20 according to an embodiment of the present invention includes the caulking portion 22, the sealing body 30 may be fixed by the caulking portion 22. A sealing gasket 90 may be interposed between the sealing body 30 and the caulking portion 22 of the battery can 20 to ensure the airtightness of the battery can 20. On the other hand, as described above, the battery can 20 according to an embodiment of the present invention may not include the beading portion 21 and / or the caulking portion 22. In this case, the sealing gasket 90 may be interposed between the fixed structure provided on the open portion side of the battery can 20 and the sealing body 30 to ensure the airtightness of the battery can 20.

[0103] Referring to FIGS. 5 and 6, the electrode terminal 40 may be electrically connected to the other one of the first electrode 11 and the second electrode 12. That is, the electrode terminal 40 may have a polarity opposite to that of the battery can 20. For example, the electrode terminal 40 may be electrically connected to the first electrode 11 of the electrode assembly 10. And the surface of the electrode terminal 40 can be exposed to the outside.

[0104] The electrode terminal 40 may be made of a conductive metal material. The electrode terminal 40 can penetrate, for example, substantially the center of the closed end formed at the upper end of the battery can 20. A part of the electrode terminal 40 may be exposed above the battery can 20, and the remaining part may be located inside the battery can 20. The electrode terminal 40 may be fixed, for example, by riveting on the inner surface of the closed end of the battery can 20. The electrode terminal 40 can penetrate the insulating member 60 and be coupled to the plain portion 11a provided on the first current collector 50 or the first positive electrode 11. In this case, the electrode terminal 40 may have a first polarity.

[0105] Therefore, the electrode terminal 40 can function as a first terminal in the secondary battery 1 according to an embodiment of the present invention. When the electrode terminal 40 has such a first polarity, the electrode terminal 40 is electrically insulated from the battery can 20 having a second polarity. The electrical insulation between the electrode terminal 40 and the battery can 20 can be realized in various ways.

[0106] As an example, at least a part of the plain portion 11a provided on the first current collector 50 or the first electrode 11 is provided to be covered with an insulating tape, so that electrical contact with the battery can can be prevented. The notch pattern of the insulating tape can prevent the lifting phenomenon at the end of the electrode assembly, and prevent defects in the electrical connection between the plain portion 11a provided on the first current collector 50 or the first electrode 11 and the electrode terminal 40.

[0107] As described above, by solving the lifting problem at the end of the electrode assembly and forming the tab structure of the electrode included in the electrode assembly at the plain portion, the current applied to the battery can be increased. As a result, the size of the battery can be increased, and it becomes possible to realize a high energy density and save costs.

[0108] As another example, insulation can be achieved by interposing a gasket 70 as described later between the electrode terminal 40 and the battery can 20. In contrast, insulation can be achieved by forming an insulating coating layer on a part of the electrode terminal 40. Alternatively, a method of structurally and firmly fixing the electrode terminal 40 may be applied so that contact between the electrode terminal 40 and the battery can 20 becomes impossible. Alternatively, a plurality of the methods described above may be applied together.

[0109] Referring to FIG. 6, the first current collector 50 may be coupled to the upper part of the electrode assembly 10. For example, the first current collector 50 may be coupled to a plain portion 11a provided on the first electrode 11 at the upper part of the electrode assembly 10. The first current collector 50 may be made of a conductive metal material. Although not shown, the first current collector 50 may have a plurality of irregularities formed radially on its lower surface.

[0110] When the irregularities are formed, the first current collector 50 can be pressed and the irregularities can be press-fitted into the plain portion 11a provided on the first electrode 11.

[0111] The secondary battery 1 according to another embodiment of the present invention may not include the first current collector 50. In this case, the plain portion 11a provided on the first electrode 11 can be directly electrically connected to the electrode terminal 40.

[0112] Referring to FIG. 6, the first current collector 50 may be coupled to an end of the plain portion 11a provided on the first electrode 11. The connection between the plain portion 11a provided on the first electrode 11 and the first current collector 50 may be performed by, for example, laser welding. The laser welding may be performed in a manner of partially melting the base material of the first current collector 50, or may be performed with a solder for welding interposed between the first current collector 50 and the plain portion 11a. In this case, the solder preferably has a melting point lower than that of the first current collector 50 and the plain portion 11a. On the other hand, in addition to laser welding, resistance welding, ultrasonic welding, etc. are possible, but the welding method is not limited thereto.

[0113] FIG. 9 is a drawing showing a schematic configuration of an electrode assembly according to another embodiment of the present invention.

[0114] Referring to FIG. 9, the first current collector 50 may be coupled to a bonding surface formed by bending an end of the plain portion 11a provided on the first electrode 11 in a direction parallel to the first current collector 50. The bending direction of the plain portion 11a may be, for example, a direction toward the winding center C of the electrode assembly 10. When the plain portion 11a has such a bent form, the space occupied by the plain portion 11a is reduced, which can lead to an improvement in energy density. Further, an increase in the bonding area between the plain portion 11a and the first current collector 50 can bring about an improvement in bonding force and a resistance reduction effect.

[0115] Referring to FIGS. 6 and 7, the insulating member 60 may be provided between the upper end of the electrode assembly 10 and the inner surface of the battery can 20, between the first current collector 50 coupled to the upper part of the electrode assembly 10 and the inner surface of the battery can 20, or between the insulating tape 100 provided on the upper part of the electrode assembly 10 and the inner surface of the battery can 20. The insulating member 60 prevents contact between the plain portion 11a provided on the first electrode 11 and the battery can 20, contact between the first current collector 50 and the battery can 20, and / or contact between the insulating tape 100 and the battery can 20. That is, the insulating member 60 is housed inside the battery can 20 and is configured to block an electrical connection between the plain portion 11a provided on the first electrode 11 and the battery can 20. Therefore, the insulating member 60 may be made of a material having insulating properties. For example, the insulating member 60 may contain a polymer material. The insulating member 60 may include a "⊂"-shaped insulating member or a "-"-shaped insulating member.

[0116] Referring to FIGS. 5 and 6, the gasket 70 is interposed between the battery can 20 and the electrode terminal 40 to prevent the battery can 20 and the electrode terminal 40 having opposite polarities from contacting each other. That is, the gasket 70 cuts off the electrical connection between the battery can 20 and the electrode terminal 40. Thereby, the upper surface of the battery can 20 having a substantially flat shape can function as the terminal of the second electrode 12 of the secondary battery 1.

[0117] Referring to FIGS. 6 and 7, the second current collector 80 may be coupled to the lower part of the electrode assembly 10. The second current collector 80 may be made of a conductive metal material. The second current collector 80 may be connected to the plain portion 12a provided on the second electrode. Further, the second current collector 80 may be electrically connected to the battery can 20. As shown in FIG. 2, the second current collector 80 may be interposed and fixed between the inner surface of the battery can 20 and the sealing gasket 90. Alternatively, the second current collector 80 may be welded to the inner wall surface of the battery can 20.

[0118] Although not shown, the second current collector 80 may be provided with a plurality of irregularities formed radially on one surface thereof. When the irregularities are formed, the second current collector 80 may be pressed and the irregularities may be press-fitted into the plain portion 12a provided on the second electrode 12.

[0119] Referring to FIGS. 6 and 8, the second current collector 80 may be coupled to the end of the plain portion 12a provided on the second electrode 12. The connection between the plain portion 12a provided on the second electrode 12 and the second current collector 80 may be performed, for example, by laser welding. The laser welding may be performed in a manner of partially melting the base material of the second current collector 80, or may be performed with a solder for welding interposed between the second current collector 80 and the plain portion 12a. In this case, the solder preferably has a lower melting point than the second current collector 80 and the plain portion 12a. On the other hand, in addition to laser welding, resistance welding, ultrasonic welding, etc. are possible, but the welding method is not limited thereto.

[0120] Although not shown, the second current collector 80 may be coupled to a bonding surface formed by bending an end of the plain portion 12a provided on the second electrode 12 in a direction parallel to the second current collector 80. The bending direction of the plain portion 12a provided on the second electrode 12 may be, for example, a direction toward the winding center C of the electrode assembly 10. When the plain portion 12a provided on the second electrode 12 has such a bent configuration, the space occupied by the plain portion 12a is reduced, which can lead to an improvement in energy density. Further, an increase in the bonding area between the plain portion 12a and the second current collector 80 can result in an improvement in bonding force and a resistance reduction effect.

[0121] Since the electrode assembly 10 according to the embodiment of FIG. 9 is similar to the electrode assembly 10 of the embodiment of FIG. 8, repetitive description of substantially the same or similar configurations as those of the above-described embodiment will be omitted, and hereinafter, the description will focus on the differences from the above-described embodiment.

[0122] Referring to FIG. 9, the electrode assembly 10 according to another embodiment of the present invention may have a structure in which at least a part of the plain portions 11a and 12a is bent toward the core side. For example, referring to FIG. 9, at least a partial section of the plain portions 11a and 12a may be divided into a plurality of segmented pieces. Here, the plurality of segmented pieces may have a structure in which they are multiply superimposed while being bent toward the core side. For example, the plurality of segmented pieces may be notched by a laser. The segmented pieces may be formed by a known metal foil cutting process such as ultrasonic cutting or punching.

[0123] According to one embodiment, the area of the first electrode or the second electrodes 11 and 12, or the plain portions 11a and 12a of the electrodes, exposed at the end of the electrode assembly may be the total area of the end of the electrode assembly minus the area of the core portion.

[0124] When bending the non-coated portions 11a and 12a, in order to prevent damage to the active material layer and / or the insulating layer, it is preferable to form a predetermined gap between the lower end of the cutting line between the segmented pieces and the active material layer. This is because when the non-coated portions 11a and 12a are bent, stress is concentrated near the lower end of the cutting line. The gap is preferably 0.2 to 4 mm. When the gap is adjusted within the numerical range, it is possible to prevent the active material layer near the lower end of the cutting line from being damaged by the stress generated during the bending process of the non-coated portions 11a and 12a. In addition, the gap can prevent damage to the active material layer due to the tolerance during the notching or cutting of the segmented pieces.

[0125] The bending direction of the non-coated portions 11a and 12a may be, for example, a direction toward the winding center C of the electrode assembly 10. When the non-coated portions 11a and 12a have such a bent form, the space occupied by the non-coated portions 11a and 12a is reduced, which can lead to an improvement in energy density. In addition, an increase in the bonding area between the non-coated portions 11a and 12a and the current collectors 50 and 80 can bring about an improvement in the bonding force and a resistance reduction effect. Therefore, the current applied to the battery can be increased. As a result, the size of the battery can be increased, enabling the realization of a high energy density and cost savings.

[0126] According to an embodiment of the present invention, the secondary battery is a cylindrical secondary battery. In one example, the secondary battery may include a battery can in which the jelly roll is accommodated. The battery can may be cylindrical, and its size may be such that the circular diameter at both ends is 30 mm to 55 mm and the height is 60 mm to 120 mm. For example, the circular diameter × height of the cylindrical battery can may be 40 mm × 60 mm, 40 mm × 80 mm, 40 mm × 90 mm, or 40 mm × 120 mm. The secondary battery may be a battery cell.

[0127] Preferably, the cylindrical battery cell may be, for example, a cylindrical battery cell having a form factor ratio (defined as the ratio of the diameter of the cylindrical battery cell to its height, i.e., the ratio of height H to diameter Φ) greater than approximately 0.4.

[0128] Here, the form factor means a value indicating the diameter and height of the cylindrical battery cell. The cylindrical battery cell according to an embodiment of the present invention may be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, a 46800 cell, or a 46900 cell. In the numerical value indicating the form factor, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0129] The battery cell according to an embodiment of the present invention may be a substantially cylindrical cell having a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0130] The battery cell according to another embodiment may be a substantially cylindrical cell having a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0131] The battery cell according to still another embodiment may be a substantially cylindrical cell having a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0132] The battery cell according to still another embodiment may be a substantially cylindrical cell having a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0133] The battery cell according to still another embodiment may be a substantially cylindrical cell having a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0134] Battery cells according to other embodiments may be substantially cylindrical cells with a diameter of approximately 46 mm, a height of approximately 90 mm, and a form factor ratio of 0.511, which may be cylindrical battery cells.

[0135] Conventionally, battery cells with a form factor ratio of approximately 0.4 or less have been used. That is, conventionally, for example, 18650 cells, 21700 cells, etc. have been used. In the case of 18650 cells, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. In the case of 21700 cells, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0136] Another embodiment of the present invention provides a battery module and a battery pack including the secondary battery according to the above-described embodiment.

[0137] The secondary battery according to the above-described embodiment may be used to manufacture the battery pack.

[0138] FIG. 15 is a drawing showing a schematic configuration of a battery pack including the secondary battery of FIG. 6.

[0139] Referring to FIG. 15, a battery pack 3 according to an embodiment of the present invention includes an assembly in which secondary batteries 1 are electrically connected, and a pack housing 2 that houses the same. The secondary battery 1 is a battery cell according to the above-described embodiment. In the drawing, for the sake of illustration, the illustration of components such as bus bars, cooling units, and external terminals for the electrical connection of the cylindrical secondary battery 1 is omitted.

[0140] Another embodiment of the present invention provides an automobile including the battery pack according to the above-described embodiment. The battery pack 3 can be mounted on an automobile. The automobile may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile includes four-wheel vehicles or two-wheel vehicles.

[0141] FIG. 16 is a drawing showing a schematic configuration of an automobile including the battery pack of FIG. 15.

[0142] Referring to FIG. 16, an automobile 5 according to an embodiment of the present invention includes a battery pack 3 according to an embodiment of the present invention. The automobile 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.

[0143] As described above, the present invention has been described with reference to limited embodiments and drawings. However, the present invention is not limited thereto, and various modifications and variations can be made within the equivalent scope of the technical idea and claims of the present invention by those having ordinary knowledge in the technical field to which the present invention belongs.

Example

[0144] [Example 1] (1) Manufacture of jelly roll A negative electrode (negative electrode current collector: Cu foil, negative electrode active material: 50 parts by weight each of artificial graphite and natural graphite), a sheet-like polyethylene separator, a positive electrode (positive electrode current collector: Al foil, active material: LiCoO2), and the polyethylene separator were sequentially laminated and wound to manufacture an electrode assembly. The diameter of the end portion perpendicular to the winding axis of the electrode assembly is 45 mm.

[0145] An insulating tape made of a polyimide material having a notch pattern (notch pattern shape: trapezoid, flag shape: triangle) was attached so as to cover the side surface of the electrode assembly and the exposed positive electrode non-coated portion at the end portion of the electrode assembly. The insulating tape having the notch pattern includes a portion covering the side surface of the electrode assembly and a portion covering the end portion, and each length is 7 mm, and a tape having a thickness of 17.5 μm (fabric: 12.5 μm, adhesive layer: 5 μm) was used.

[0146] In the region covering the end portion of the electrode assembly, the insulating tapes did not overlap each other. The area of the insulating tape covering the end portion of the electrode assembly was calculated by Experimental Example 1 described later, and the insulating tape covered about 26.7% of the positive electrode non-coated portion at the end portion of the electrode assembly.

[0147] A jelly roll was manufactured such that an insulating member (a "⊂"-shaped insulating member) covering the end portion and a part of the side surface of the electrode assembly was included on the end side of the electrode assembly to which the insulating tape was attached.

[0148] (2) Manufacture of secondary battery After inserting the manufactured jelly roll into a battery can (diameter: 45 mm to 47 mm, material: steel) having an opening on one side, an electrolytic solution in which ethylene carbonate (EC): ethyl methyl carbonate (EMC) was mixed at a volume ratio of 30:70 and dissolved so that LiPF6 became 1.0 M was injected, and the cylindrical battery can was sealed with a sealing body to manufacture a secondary battery.

[0149] An electrode terminal was riveted through a through-hole formed at the bottom of the battery can, and a gasket was provided between the electrode terminal and the outer diameter of the through-hole to manufacture a riveting structure of the electrode terminal. In the secondary battery including this, the negative electrode of the jelly roll and the battery can were electrically connected, the positive electrode and the electrode terminal were electrically connected, and the sealing body was manufactured to be insulated from the battery can.

[0150] [Example 2] A jelly roll and a secondary battery were manufactured in the same manner as in Example 1, except that an insulating tape having a notch pattern and a thickness of 22.5 μm (base material: 12.5 μm, adhesive layer: 10 μm) was attached.

[0151] [Comparative Example 1] A jelly roll and a secondary battery were manufactured in the same manner as in Example 1, except that an insulating tape having no notch pattern and a thickness of 30 μm (base material: 25 μm, adhesive layer: 5 μm) was attached so as to cover at least a part of the side surface of the electrode assembly and the end portion of the electrode assembly.

[0152] [Comparative Example 2] A jelly roll and a secondary battery were manufactured in the same manner as in Comparative Example 1, except that an insulating tape having no notch pattern and a thickness of 17.5 μm (base material: 12.5 μm, adhesive layer: 5 μm) was attached.

[0153] [Comparative Example 3] A jelly roll and a secondary battery were manufactured in the same manner as in Comparative Example 1, except that an insulating tape having a thickness of 22.5 µm (fabric: 12.5 µm, adhesive layer: 10 µm) without a notch pattern was attached.

[0154] [Experimental Example] [Experimental Example 1. Area of the insulating tape covering the end of the electrode assembly] FIG. 10 is a drawing showing the end of the electrode assembly for calculating the area of the insulating tape covering the end of the electrode assembly.

[0155] Referring to FIG. 10, the area of the insulating tape covering the exposed first electrode or second electrode at the end of the electrode assembly, or the plain portion 11a of the electrode, was calculated as follows. At this time, the diameter D of the end perpendicular to the winding axis of the electrode assembly, the length 120d of the portion covering the end of the electrode assembly with the insulating tape, and the core diameter Cd were indicated as follows. - Diameter of the end perpendicular to the winding axis of the electrode assembly: D (mm) - Length of the portion covering the end of the electrode assembly with the insulating tape: 120d (mm) - Core diameter: Cd (mm) (1) Total area of the exposed first electrode or second electrode at the end of the electrode assembly, or the plain portion (excluding the core portion) ={(D / 2) 2 -(Cd / 2) 2}*π (2) Area of the portion of the insulating tape covering the end of the electrode assembly ={(D / 2) 2 -(D / 2 - 120d) 2}*π* Notch pattern area ratio (area of the notch pattern compared to the total area of the tape) 20 - 80% (3) Area of the insulating tape covering the exposed first electrode or second electrode at the end of the electrode assembly, or the plain portion of the electrode =((2) / (1))*100 = 5 - 60%

[0156] The area of the insulating tape with the notch patterns of Examples 1 and 2 covering the end of the electrode assembly was calculated as follows. - Diameter of the end perpendicular to the winding axis of the electrode assembly: 45 mm - Length of the part of the insulating tape covering the end of the electrode assembly: 7 mm - Diameter of the core part: 6 mm (1) Total area (excluding the core part) of the first electrode or the second electrode or the plain part exposed at the end of the electrode assembly = (22.5 2 - 3 2 ) * π = 1561.4 (2) Area of the part where the insulating tape covers the end of the electrode assembly = (22.5 2 - 15.5 2 ) * π * 50% = 835.2 * 0.5 = 417.6 (3) Area of the insulating tape covering the first electrode or the second electrode exposed at the end of the electrode assembly or the plain part of the electrode = (417.6 / 1561.4) * 100 = 26.7%

[0157] [Experimental Example 2. Improvement of Adhesive Force and Lifting by Thickness of Insulating Tape] The adhesive force of the insulating tape was measured by pressing the adhesive layer of the insulating tape onto a SUS304 substrate once back and forth with a 2 kg rubber roller, leaving it to stand at 23 °C for 20 minutes, and then using a texture analyzer (Texture analyzer (Stable Micro Systems)) to peel the backplate film with the colored polyimide at an angle of 180 ° and a peeling speed of 300 mm / min.

[0158] The degree of lifting and confirmation of lifting of the jelly roll were determined by measuring the height of the insulating tape lifted from the end of the electrode assembly. When the height of the insulating tape lifted at the end of the electrode assembly of the jelly roll was 2 mm or more, it was indicated as ○; when it was 1 mm to 2 mm, it was indicated as △; and when it was 1 mm or less, it was indicated as ×, and this was described in Table 1 below.

[0159] The confirmation of the lifting in Example 1 is shown in FIG. 11, the confirmation of the lifting in Comparative Example 1 is shown in FIG. 12, and the confirmation of the lifting in Comparative Example 3 is shown in FIG. 13 respectively. The confirmation of the lifting in Example 2 may be the same as that in FIG. 11 in that the degree of lifting cannot be distinguished by the naked eye compared with Example 1. The confirmation of the lifting in Comparative Example 2 may be the same as that in FIG. 12 in that the degree of lifting cannot be distinguished by the naked eye compared with Comparative Example 1.

[0160]

Table 1

[0161] Referring to Table 1 and FIGS. 11 to 13, Examples 1 and 2 include an insulating tape having a notch pattern according to an embodiment of the present invention, and it was confirmed that there was less lifting at the end of the electrode assembly of the jelly roll compared with Comparative Examples 1 to 3 including insulating tapes having no such notch pattern. Therefore, Examples 1 and 2 can prevent the lifting phenomenon at the end of the electrode assembly compared with Comparative Examples 1 to 3, and prevent defects in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0162] Examples 1 and 2 have a difference in the thickness of the insulating tape, particularly the thickness of the adhesive layer. In Example 2, the thickness of the adhesive layer is twice as thick as that in Example 1, the adhesive force is high, and it was confirmed that there was less lifting at the end of the electrode assembly.

[0163] Comparative Examples 1 and 2 have a difference in the thickness of the insulating tape, particularly the thickness of the fabric layer. In Comparative Example 2, the thickness of the fabric is 1 / 2 times that in Comparative Example 1, the adhesive force is small, but it was confirmed that the degree of lifting was improved. Thereby, it can be seen that using an insulating tape with a thicker adhesive layer than the thickness of the fabric improves the degree of lifting.

[0164] Example 1 and Comparative Example 2, and Embodiment 2 and Comparative Example 3 are such that the thicknesses of the fabric and the adhesive layer are the same with insulating tape, but there is a difference only in the presence or absence of notches. Even when the thicknesses of the fabric and the adhesive layer of the insulating tape are the same, it can be confirmed that Examples 1 and 2 with notching have improved lifting at the end of the electrode assembly compared to Comparative Examples 2 and 3, thereby preventing defects in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0165] Therefore, the insulating tape having the notch pattern can adhere better at the end of the electrode assembly. Specifically, it can be seen that the thinner the thickness of the fabric of the insulating tape, the more advantageous it may be, and the thicker the thickness of the adhesive layer of the insulating tape, the better it can adhere at the end of the electrode assembly.

[0166] In particular, compared with Comparative Example 1, in Example 1, the thickness of the fabric of the insulating tape was reduced by about 50%, and the thickness of the adhesive layer was increased by about 150%. That is, it was confirmed that the thickness of the fabric of the insulating tape was thin and the thickness of the adhesive layer of the insulating tape was thick, which was advantageous for adhesion at the end of the electrode assembly.

[0167] [Experimental Example 3. AC Resistance Measurement] The AC resistance of the secondary battery was measured using a battery tester (equipped with HIOKI battery tester BT3554-51) under normal temperature conditions. With the battery tester, two leads were respectively brought into contact with the positive electrode terminal portion (riveted electrode terminal) and the negative electrode terminal portion (battery can) for measurement.

[0168] The measurement of the AC resistance of the secondary battery is a method of measuring the resistance of the battery by applying a fine AC signal to the battery by measuring the internal resistance by the AC method. By measuring this, it is possible to indirectly confirm defects in the electrical connection between the electrode tab portion and the electrode terminal portion.

[0169] The AC resistance of the secondary batteries according to Examples 1 and 2 and Comparative Examples 1 to 3 was measured 10 times and averaged, and the results are shown in Table 2 and FIG. 14.

[0170]

Table 2

[0171] Referring to Table 2 and FIG. 14, Example 1 has a notch pattern according to an embodiment of the present invention and includes an insulating tape with a relatively thin thickness. It was confirmed that the AC resistance value was lower compared to Comparative Example 1, which does not have the notch pattern and includes an insulating tape with a relatively thick thickness.

[0172] Comparative Examples 1 and 2 are cases where there is a difference in the thickness of the insulating tape, particularly the thickness of the fabric layer. In Comparative Example 2, the thickness of the fabric is 1 / 2 times that of Comparative Example 1, and the adhesive force is small, but it was confirmed that the AC resistance was improved. Thereby, it can be seen that using an insulating tape with a thicker adhesive layer compared to the thickness of the fabric improves the AC resistance.

[0173] Also, it was confirmed that Comparative Examples 2 and 3 have a higher AC resistance value than Examples 1 and 2, even though the thicknesses of the insulating tape, fabric, and adhesive layer are the same as those of Examples 1 and 2, and include an insulating tape without a notch pattern.

[0174] This is because the notch pattern of the insulating tape minimizes the area where the insulating tapes overlap each other at the end of the electrode assembly, prevents the lifting phenomenon at the end of the electrode assembly, and can prevent defects in the electrical connection between the electrode tab portion and the electrode terminal portion. It was confirmed that the thicker the thickness of the insulating tape, particularly the adhesive layer, the more advantageous it is for adhesion at the end of the electrode assembly.

Explanation of Reference Numerals

[0175] 1 ··· Secondary battery 2 ··· Pack housing 3 ··· Battery pack 5 ··· Automobile 10 ··· Electrode assembly 10’ ··· Jelly roll C ··· Core part Cd ··· Core part diameter 11 ··· First electrode 11a ··· Plain part 11b ··· Active material part 12 ··· Second electrode 12a ··· Plain part 12b ··· Active material part 13 ··· Separator 20 ··· Battery can 21 ··· Beading part 22 ··· Crimping part 30 ··· Sealing body 40 ··· Electrode terminal 45 ··· Through hole 50 ··· First current collector 60 ··· Insulating member 70 ··· Gasket 80 ··· Second current collector 90 ··· Sealing gasket 100 ··· Insulating tape 100’ ··· Lifted part of insulating tape 110 ··· Part covering the side surface of the electrode assembly with insulating tape 120 ··· Part covering the end of the electrode assembly with insulating tape 120d ··· Length of the part covering the end of the electrode assembly with insulating tape 130 ··· Shape of notch pattern 140 ··· Flag shape D ··· Diameter of the end perpendicular to the winding axis of the electrode assembly

Claims

1. An electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound; and An insulating tape provided so as to cover a part of a side surface and a part of an end portion of the electrode assembly including the insulating tape has at least one notch pattern provided in a region covering a part of the end portion of the electrode assembly, further including a current collector plate provided on the end side of the electrode assembly, the current collector plate is located between the insulating tape and the electrode assembly in a region where the insulating tape covers the end portion of the electrode assembly, and contacts the insulating tape and the end portion of the electrode assembly, A jelly roll.

2. In the entire area where the insulating tape covers the end portion of the electrode assembly, the area where the insulating tapes overlap each other is 10% or less, The jelly roll according to Claim 1.

3. The insulating tapes do not overlap each other in a region where the insulating tape covers the end portion of the electrode assembly, The jelly roll according to Claim 1.

4. The insulating tape has two or more notch patterns, and the flag shape provided between two adjacent notch patterns is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semicircle, The jelly roll according to any one of Claims 1 to 3.

5. The shape of the notch pattern of the insulating tape is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semicircle, The jelly roll according to any one of Claims 1 to 3.

6. At least one of the first electrode and the second electrode includes a current collector and an electrode active material layer provided on the current collector, and the current collector includes a plain portion without the electrode active material layer, At least a part of the plain portion is exposed on the side surface of the electrode assembly body, The insulating tape is provided so as to cover the plain portion on the side surface of the electrode assembly body. The jelly roll according to any one of claims 1 to 3.

7. The insulating tape is provided so as to cover 5% to 60% of the first electrode or the second electrode exposed at the end of the electrode assembly body. The jelly roll according to any one of claims 1 to 3.

8. At least a part of the plain portion is exposed at the end of the electrode assembly body, The insulating tape is provided so as to cover 5% to 60% of the plain portion at the end of the electrode assembly body. The jelly roll according to claim 6.

9. The thickness of the insulating tape is 10 μm to 100 μm. The jelly roll according to any one of claims 1 to 3.

10. The insulating tape includes a fabric and an adhesive layer, The thickness of the fabric is 3 μm to 25 μm, and the thickness of the adhesive layer is 2 μm to 20 μm. The jelly roll according to any one of claims 1 to 3.

11. The insulating tape includes one or more selected from the group consisting of polyimide, polyethylene, polypropylene, polytetrafluoroethylene, polyethylene terephthalate, and polybutylene terephthalate. The jelly roll according to any one of claims 1 to 3.

12. Further comprising a second current collector plate located on the other end side, which is the opposite side of the surface of the electrode assembly facing the insulating tape. The jelly roll according to any one of Claims 1 to 3.

13. Further comprising an insulating member provided so as to cover at least a part of the end of the electrode assembly or at least a part of the end of the electrode assembly and at least a part of the side surface of the electrode assembly on the end side of the electrode assembly. The jelly roll according to any one of Claims 1 to 3.

14. An insulating tape for adhering so as to cover a part of the side surface and a part of the end of an electrode assembly having a structure in which a first electrode, a separator, and a second electrode are laminated and wound, Having at least one notch pattern on at least one edge portion, Insulating tape.

15. The insulating tape has two or more notch patterns, and the flag shape provided between two adjacent notch patterns is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semi-circle. The insulating tape according to Claim 14.

16. The shape of the notch pattern of the insulating tape is at least one of a trapezoid, a quadrilateral, a parallelogram, a triangle, and a semi-circle. The insulating tape according to Claim 14 or 15.

17. The jelly roll according to any one of Claims 1 to 3; A battery can having an opening on one side for housing the jelly roll; An electrode terminal riveted through a through hole formed in the bottom of the battery can; A gasket provided between the electrode terminal and the outer diameter of the through hole; and A sealing body for sealing the opening of the battery can including a secondary battery.

18. The secondary battery is cylindrical. The secondary battery according to claim 17.

19. The first electrode is electrically connected to the electrode terminal, the second electrode is electrically connected to the battery can, and the sealing member is insulatable from the battery can. The secondary battery according to claim 17.

20. A battery module including the secondary battery according to claim 17.

21. A battery pack including the secondary battery according to claim 17.

22. An automobile including the battery pack according to claim 21.

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