Jelly roll, secondary battery, battery pack, and automobile

Abstract

One embodiment of the present invention provides a jelly roll including: an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and a tube structure provided to surround at least a portion of a side surface of the electrode assembly and at least a portion of one end of the electrode assembly perpendicular to a winding axis, the tube structure including a hole formed in the center of the one end of the electrode assembly perpendicular to the winding axis, and a secondary battery, a battery pack, and an automobile including the jelly roll.

Description

[Technical field]

[0001] The present invention relates to a jelly roll, a secondary battery, a battery pack, and an automobile. This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0154665 filed with the Korean Intellectual Property Office on November 17, 2022, and all contents disclosed in the documents of the Korean patent application are incorporated herein by reference. [Background technology]

[0002] Secondary batteries, which have high ease of application depending on the product group and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical sources.

[0003] Such secondary batteries have the primary advantage of dramatically reducing the use of fossil fuels, as well as the advantage of not producing any by-products associated with energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and can improve energy efficiency.

[0004] Currently, the types of secondary batteries that are widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack may be configured by connecting a plurality of secondary batteries in series. Also, a battery pack may be configured by connecting a plurality of secondary batteries in parallel depending on the charge / discharge capacity required for the battery pack. Therefore, the number and electrical connection form of the secondary batteries included in the battery pack may be variously set depending on the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, cylindrical, square, and pouch-type secondary batteries are known as types of secondary batteries. The secondary battery may be a cylindrical secondary battery. The secondary battery is formed by interposing a separator, which is an insulator, between a positive electrode and a negative electrode, rolling up the electrode assembly in a jelly roll shape, and inserting the electrode assembly together with an electrolyte into a battery can to form a battery. Strip-shaped electrode tabs are connected to the uncoated portions of the positive electrode and the negative electrode, and the electrode tabs electrically connect the electrode assembly to electrode terminals exposed to the outside. For reference, the positive electrode terminal is a cap plate of a sealed body that seals the open portion of the battery can, and the negative electrode terminal is the battery can.

[0006] However, conventional secondary batteries having such a structure have problems in that current is concentrated in the strip-shaped electrode tabs connected to the positive electrode uncoated area and / or the negative electrode uncoated area, resulting in high resistance, a lot of heat generation, and poor current collection efficiency.

[0007] Small cylindrical secondary batteries with form factors of 18650 and 21700 do not have significant problems with resistance and heat generation. However, when the form factor of cylindrical secondary batteries is increased to apply them to electric vehicles, a large amount of heat is generated around the electrode tabs during fast charging, which may cause the cylindrical secondary battery to catch fire. Therefore, there is a demand for the development of cylindrical secondary batteries with even higher form factors. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a jelly roll and a secondary battery that can achieve high energy density by including a tube structure that is provided to surround a side surface of an electrode assembly and one end of the electrode assembly that is perpendicular to the winding axis.

[0009] Another object of the present invention is to provide a battery pack including a secondary battery having the above-mentioned improved structure, and a vehicle including the same.

[0010] However, the technical problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0011] One embodiment of the present invention provides a jelly roll including: an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and a tube structure provided to surround at least a portion of a side surface of the electrode assembly and at least a portion of one end portion perpendicular to a winding axis of the electrode assembly, the tube structure being provided to include a hole formed in the center of the one end portion perpendicular to the winding axis of the electrode assembly.

[0012] Another embodiment of the present invention provides a secondary battery including a jelly roll according to one embodiment of the present invention; and a battery can housing the jelly roll, the battery can including an electrode terminal riveted through a through hole formed in a bottom of the battery can, and a gasket provided between the electrode terminal and an outer diameter of the through hole.

[0013] Another embodiment of the present invention provides a battery pack including the secondary battery according to the above embodiment.

[0014] Another embodiment of the present invention provides a vehicle including a battery pack according to the above-described embodiment. Effect of the Invention

[0015] Due to the development of secondary batteries that require high capacity and high power, a positive electrode uncoated area and a negative electrode uncoated area are located at one end perpendicular to the winding axis of a jelly roll type electrode assembly and the other end opposite the one end, respectively, and current collecting plates are welded to these uncoated areas to improve current collection efficiency, thereby lowering the internal resistance of the secondary battery and increasing the energy density.

[0016] Conventionally, after the positive electrode current collector plate of the electrode assembly is laser-welded to the positive electrode uncoated portion, insulating tape is applied to the exposed uncoated portion and the current collector plate to insulate the uncoated portion and the portion where the current collector plate and the battery can abut against each other. When insulating tape is applied, it is disadvantageous in terms of appearance quality and process, and there is a problem that the insulating tape may peel off when the jelly roll is inserted into the battery can due to problems of wrinkles and lifting.

[0017] According to an embodiment of the present invention, the electrode assembly includes a tube structure provided to surround at least a portion of a side surface of the electrode assembly and one end perpendicular to the winding axis of the electrode assembly, which prevents problems such as wrinkles and lifting caused by the insulating tape, thereby improving insulation quality, shortening the time required to produce one product, and improving process capacity. In addition, the electrode assembly can be smoothly inserted into a battery can, which is easy to rework and advantageous for cost reduction.

[0018] This makes it possible to stably increase the current applied to the battery, thereby realizing a high energy density and providing a high-capacity, high-output secondary battery.

[0019] However, the advantageous effects obtained by the present invention are not limited to those described above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0020] 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 ideas of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0021] [Figure 1] 1(a) and 1(b) are schematic diagrams illustrating a jelly roll including a tube structure according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a schematic diagram illustrating a structure of a secondary battery including a jelly roll according to an embodiment of the present invention. [Diagram 3] Photographs showing (a) the process of a jelly roll to which an insulating tape according to a comparative example of the present invention has been applied, (b) one end perpendicular to the winding axis of the electrode assembly, (c) the shape of wrinkles and lifting of the insulating tape, and (d) the shape of the insulating tape peeling off when inserted into a battery can. [Figure 4] Photographs showing (a) a process of the tube structure of a small cylindrical secondary battery having a form factor of 21700 according to a comparative example of the present invention, (b) one end perpendicular to the winding axis of the electrode assembly, and (c) a side view of the electrode assembly. [Diagram 5] 1 is a diagram showing a schematic configuration of a battery pack including a secondary battery according to an embodiment of the present invention; [Figure 6] 1 is a diagram showing a schematic configuration of an automobile including a battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0023] The terms used in this specification are merely used to describe exemplary embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless otherwise clearly indicated in the context.

[0024] In this specification, terms such as "comprise," "provide," or "have" are intended to describe the presence of certain components, and do not preclude the presence or possible addition of other components.

[0025] Furthermore, the terms "unit" and "apparatus" used in this specification refer to a unit that processes at least one function or operation.

[0026] In this specification, the expression "on" a particular component is intended to indicate that the component is on one side of the particular component, and is not intended to limit the hierarchical relationship. It is also not limited to being in physical contact with the particular component, and means that other components may be further provided between the particular component.

[0027] In this specification, the term "tube structure" refers to a structure that seamlessly surrounds the jelly roll, unlike insulating tape.

[0028] The embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, so it should be understood that there may be various equivalents and modifications that can replace them at the time of filing this application.

[0029] In order to facilitate understanding of the invention, the accompanying drawings may be drawn not to scale, and some dimensions of components may be exaggerated. In addition, the same reference numerals may be used to refer to the same components in different embodiments.

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0031] One embodiment of the present invention provides a jelly roll including: an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and a tube structure provided to surround at least a portion of a side surface of the electrode assembly and at least a portion of one end portion perpendicular to a winding axis of the electrode assembly, the tube structure being provided to include a hole formed in the center of the one end portion perpendicular to the winding axis of the electrode assembly.

[0032] The tube structure is a structure that is differentiated from an insulating tape, and refers to a structure that seamlessly surrounds a jelly roll.

[0033] By including a tube structure provided to surround at least a portion of the side of the electrode assembly and one end perpendicular to the winding axis of the electrode assembly, the insulating quality is improved since there is no problem of wrinkles or lifting compared to insulating tape, and the time required to produce one product (tact time) is shortened, thereby improving process capacity. In addition, it is easy to insert into a battery can, making rework easy and advantageous for cost reduction.

[0034] The tube structure includes a hole formed at the center of one end perpendicular to the winding axis of the electrode assembly, and the one end is open, which makes it easy to apply the tube structure to the electrode assembly. Specifically, since the tube material used for the tube structure is provided in a reel type, it can be cut and inserted, which is advantageous in terms of realizing a process for producing the tube structure including the hole.

[0035] 1(a) and (b) are schematic diagrams each showing a jelly roll including a tube structure according to an embodiment of the present invention.

[0036] Referring to Figures 1(a) and (b), a tube structure 10 can be provided to surround at least a portion of a side surface 2 of the electrode assembly and at least a portion of one end portion 3 perpendicular to the winding axis of the electrode assembly.

[0037] In a secondary battery requiring high capacity and high output, positive and negative uncoated areas may be located at one end perpendicular to the winding axis of the electrode assembly and the other end opposite the one end, and a current collector plate may be welded to the uncoated area to improve current collection efficiency. This reduces the internal resistance of the secondary battery and increases the energy density. After the positive current collector plate 7 of the electrode assembly 1 is laser welded to the positive uncoated area 6, the tube structure 10 may be included for insulation at the area where the positive uncoated area 6 and the positive current collector plate 7 abut against the battery can 31.

[0038] The positive electrode uncoated portion 6 and the positive electrode current collector 7 are exposed, and the electrode assembly includes a tube structure 10 that surrounds the side surface 2 of the electrode assembly against which the battery can 31 can abut, and one end portion 3 perpendicular to the winding axis of the electrode assembly. This improves insulation quality and facilitates insertion of the electrode assembly into the battery can.

[0039] Referring to FIG. 1(a), in one embodiment of the present invention, a tube structure 10 is provided to surround at least a part of the side surface 2 of the electrode assembly and at least a part of one end 3 perpendicular to the winding axis of the electrode assembly, and is provided to include a hole 11 formed in the center of the one end perpendicular to the winding axis of the electrode assembly. The tube structure 10 may be provided for insulation at the part where the positive electrode uncoated portion 6 and the positive electrode current collector plate 7 are exposed and the battery can 31 abuts on the side surface 2 of the electrode assembly and the one end 3 perpendicular to the winding axis of the electrode assembly. In addition, since there is no problem of wrinkles or lifting compared to insulating tape, the insulation quality is improved, the time required to produce one product is shortened, and the process capacity can be improved by replacing the taping process. As a result, insertion into the battery can is smooth, rework is easy, and it is advantageous for cost reduction.

[0040] 1(b), in another embodiment of the present invention, a tube structure 10 may be provided to surround at least a portion of one end 3 perpendicular to the winding axis of the electrode assembly, a hole 11 may be formed in the center of the one end, and the tube structure 10 may be provided to surround not a portion but the entire side surface 2 of the electrode assembly. As a result, the positive electrode uncoated portion 6 and the positive electrode current collector plate 7 may be exposed at the side surface 2 of the electrode assembly and the one end 3 perpendicular to the winding axis of the electrode assembly, and the tube structure 10 may be provided for insulation at the portion where the battery can 31 abuts. In this case, the tube structure 10 may be provided to replace the role of a fixing tape that fixes the jelly roll 20 before insertion into the battery can 31, which is advantageous in terms of processing.

[0041] In one embodiment of the present invention, the tube structure is provided to include a hole formed in the center of one end perpendicular to the winding axis of the electrode assembly.

[0042] The hole formed at the center of one end 3 perpendicular to the winding axis of the electrode assembly means a hole formed from the center point of a circle which is a cross section perpendicular to the winding axis of the electrode assembly.

[0043] FIG. 2 is a schematic diagram illustrating a structure of a secondary battery including a jelly roll according to an embodiment of the present invention.

[0044] Referring to FIG. 2, as described below, a secondary battery according to an embodiment of the present invention includes a jelly roll 20 according to an embodiment of the present invention; and a battery can 31 housing the jelly roll 20, and the battery can 31 includes an electrode terminal 100 riveted through a through hole 300 formed in a bottom 200 of the battery can, and a gasket 400 provided between the electrode terminal 100 and the outer circumference of the through hole 300.

[0045] In the electrode assembly, the positive electrode current collector 7 welded to the positive electrode uncoated portion 6 can be electrically connected to the riveted electrode terminal 100 through a through hole 300 formed in the bottom 200 of the battery can. For this purpose, the positive electrode current collector 7 and the riveted electrode terminal 100 must be welded, and can be electrically connected through a hole 11 formed in the center of one end 3 perpendicular to the winding axis of the electrode assembly provided in the tube structure 10. In addition, the exposed positive electrode uncoated portion 6 and the positive electrode current collector 7 of the electrode assembly 1 in the remaining portion that abuts against the battery can 31 can be insulated by the tube structure 10. As a result, the current applied to the battery can be stably increased, a high energy density can be realized, and a high-capacity and high-power secondary battery can be provided.

[0046] FIG. 3 is a photograph showing (a) the process of a jelly roll to which insulating tape has been attached according to a comparative example of the present invention, (b) one end perpendicular to the winding axis of the electrode assembly, (c) the form of wrinkles and lifting of the insulating tape, and (d) the form in which the insulating tape peels off when inserted into a battery can. FIG. 4 is a photograph showing (a) the process of a tube structure of a small cylindrical secondary battery having a 21700 form factor according to a comparative example of the present invention, (b) one end perpendicular to the winding axis of the electrode assembly, and (c) the side of the electrode assembly.

[0047] 3(a) to 3(d), after the positive current collector plate of the electrode assembly is laser-welded to the positive uncoated portion, insulating tape can be attached to the exposed positive uncoated portion and the positive current collector plate to insulate the positive uncoated portion and the portion where the positive current collector plate and the battery can abut against each other. When insulating tape is attached, there is a problem that the insulating tape peels off when the jelly roll is inserted into the battery can due to the problem of the insulating tape being wrinkled or lifted, which is disadvantageous in appearance quality and process.

[0048] Also, referring to (a) to (c) of FIG. 4, the tube structure of a small cylindrical secondary battery having a form factor of 21700 is provided outside the battery can, and the tube structure provided in the electrode assembly which is an embodiment of the present invention does not provide the effect of improving insulation quality and facilitating insertion into the battery can.

[0049] In one embodiment of the present invention, at least one of the positive electrode and the negative electrode includes a current collector and an electrode active material layer provided on the current collector, the current collector includes an uncoated portion on which the electrode active material layer is not provided, at least a portion of the uncoated portion is exposed to a side surface of the electrode assembly, and the tube structure is provided to surround the uncoated portion on the side surface of the electrode assembly.

[0050] In order to achieve high capacity and high output of the secondary battery, a positive electrode uncoated region and a negative electrode uncoated region are located at one end of the electrode assembly perpendicular to the winding axis and the other end opposite the one end, respectively, thereby lowering the internal resistance of the secondary battery and increasing the energy density.

[0051] In this case, by including a tube structure provided to surround the uncoated portion on the side of the electrode assembly, there is no problem of wrinkles or lifting compared to insulating tape, so the insulation quality is improved, the tact time required to produce one product is shortened, and the process capacity is improved.In addition, it is easy to insert into the battery can, making rework easy and advantageous for cost reduction.

[0052] One embodiment of the present invention provides a jelly roll further comprising a current collector provided at an end of the electrode assembly perpendicular to the winding axis, the current collector being located between the tube structure and the electrode assembly or at the other end of the electrode assembly perpendicular to the winding axis.

[0053] Among the current collector plates provided at the ends perpendicular to the winding axis of the electrode assembly, the current collector plate located between the tube structure and the electrode assembly may be a positive current collector plate, and the current collector plate located at the other end perpendicular to the winding axis of the electrode assembly may be a negative current collector plate.

[0054] In order to achieve high capacity and high output of the secondary battery, a positive electrode uncoated portion and a negative electrode uncoated portion are located at one end of the electrode assembly perpendicular to the winding shaft and the other end opposite the one end, respectively, and current collecting plates are welded to these uncoated portions to improve current collection efficiency, thereby lowering the internal resistance of the secondary battery and increasing the energy density.

[0055] By including a tube structure provided to surround the current collector plate on the side of the electrode assembly, insulation quality and process capability can be improved, and the electrode assembly can be smoothly inserted into a battery can.

[0056] In one embodiment of the present invention, there is provided an electrode assembly in which the tube structure does not extend to one end opposite to the other end perpendicular to the winding axis of the electrode assembly.

[0057] In the tube structure, the electrode assembly may be exposed over the entire surface of the other end portion opposite to the one end portion perpendicular to the winding shaft of the electrode assembly, i.e., the tube structure may not be provided on the other end portion opposite to the one end portion perpendicular to the winding shaft of the electrode assembly.

[0058] Referring to Figures 1(a) and (b), the tube structure 10 may be provided so as to extend to surround at least a portion of the side surface 2 of the electrode assembly and at least a portion of one end portion 3 perpendicular to the winding axis of the electrode assembly, but does not extend to the other end portion 4 opposite the one end portion 3 perpendicular to the winding axis of the electrode assembly.

[0059] The other end 4 facing the one end 3 perpendicular to the winding axis of the electrode assembly may be the opposite surface of the one end 3 perpendicular to the winding axis of the electrode assembly.

[0060] As described above, the positive and negative uncoated portions may be located at one end 3 perpendicular to the winding shaft of the electrode assembly and the other end 4 opposite the one end, and current collection efficiency may be improved by welding a current collector to the uncoated portions. However, if the tube structure 10 extends to the other end 4 opposite to the one end 3 perpendicular to the winding shaft of the electrode assembly, the negative uncoated portion and the negative current collector of the electrode assembly 1 may not be electrically connected to the battery can or the resistance may be increased, resulting in a reduced energy density.

[0061] In one embodiment of the present invention, the tube structure extends from the outer peripheral surface of one end perpendicular to the winding shaft of the electrode assembly to the hole, and the area of ​​the tube structure provided at the one end perpendicular to the winding shaft of the electrode assembly is 50% or less of the area of ​​the one end perpendicular to the winding shaft of the electrode assembly, which is 100%.

[0062] Referring to Figures 1(a) and (b), the area 12A of the tube structure provided at one end perpendicular to the winding axis of the electrode assembly may be 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, or 20% or less with respect to 100% of the area of ​​the one end perpendicular to the winding axis of the electrode assembly.

[0063] The area 12A of the tube structure provided at one end perpendicular to the winding shaft of the electrode assembly may be 5% or more, or 10% or more with respect to 100% of the area of ​​the one end perpendicular to the winding shaft of the electrode assembly.

[0064] According to one embodiment, the area of ​​the tube structure provided at one end perpendicular to the winding shaft of the electrode assembly may be within a range that does not affect the subsequent assembly process, and is not limited to the above range. The area of ​​the one end perpendicular to the winding shaft of the electrode assembly may be the sum of the area 12A of the tube structure provided at one end perpendicular to the winding shaft of the electrode assembly and the area of ​​the hole. The area of ​​the hole may be 50% or more of the area of ​​the one end perpendicular to the winding shaft of the electrode assembly.

[0065] The area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding shaft may be 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, or 80% or more relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding shaft. The area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding shaft may be 95% or less, or 90% or less relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding shaft.

[0066] According to one embodiment, the area 12A of the tube structure provided at one end perpendicular to the winding shaft of the electrode assembly may be 5% to 50%, 10% to 50%, 10% to 40%, 10% to 30%, or 10% to 20% of the area 100% of the one end perpendicular to the winding shaft of the electrode assembly.

[0067] According to one embodiment, the area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding shaft may be 50% to 95%, 50% to 90%, 60% to 90%, 70% to 90%, or 80% to 90% of the area of ​​the one end of the electrode assembly perpendicular to the winding shaft (100%).

[0068] When this range is satisfied, the tube structure 10 can be insulated at one end 3 perpendicular to the winding axis of the electrode assembly, where the positive electrode uncoated portion and the positive electrode current collector plate 7 are exposed and the portion where the battery can abuts can be improved in process capability.

[0069] In one embodiment of the present invention, the tube structure extends from the outer peripheral surface of one end perpendicular to the winding shaft of the electrode assembly to the hole, and the width of the tube structure provided at one end perpendicular to the winding shaft of the electrode assembly is 30% or less of the diameter of the one end perpendicular to the winding shaft of the electrode assembly.

[0070] 1(a) and 1(b), the width 12W of the tube structure provided at one end 3 perpendicular to the winding axis of the electrode assembly may be 27% or less, 24% or less, 21% or less, or 18% or less with respect to 100% of the diameter of the one end 3 perpendicular to the winding axis of the electrode assembly. The width 12W of the tube structure provided at one end 3 perpendicular to the winding axis of the electrode assembly may be 9% or more, 12% or more, or 15% or more with respect to 100% of the diameter of the one end 3 perpendicular to the winding axis of the electrode assembly.

[0071] According to one embodiment, the width of the tube structure provided at one end perpendicular to the winding axis of the electrode assembly may be within a range that does not affect the subsequent assembly process, and is not limited to the above range.

[0072] When this range is satisfied, the tube structure 10 can be insulated at one end 3 perpendicular to the winding axis of the electrode assembly, where the positive electrode uncoated portion and the positive electrode current collector plate 7 are exposed and the portion where the battery can abuts can be improved in process capability.

[0073] In one embodiment of the present invention, a jelly roll is provided, wherein the tube structure comprises a stretchable material.

[0074] When the tube structure includes an elastic material, it can be adjusted to fit the shape of the electrode assembly even if it expands to a certain extent due to repeated charging and discharging of the electrolyte, compared to when the tube structure includes a non-elastic material.

[0075] The term "containing a non-elastic material" may refer to a material that has little or no elasticity.

[0076] According to a further embodiment of the present invention, the tube structure can provide a jelly roll having insulating properties, flame retardancy, and heat resistance. By including the above-mentioned properties, the tube structure can improve insulation quality without wrinkles or lifting problems compared to insulating tape, and can shorten the time required to produce one product, thereby improving process capacity.

[0077] In one embodiment of the present invention, the tube structure includes a polyvinyl chloride (PVC+EVE) compound, but is not limited thereto as long as the tube structure is insulated.

[0078] The tube structure contains the above-mentioned compound, which can provide insulation and swelling effects. In particular, the tube structure contains the above-mentioned compound, which can shrink at room temperature, unlike PET, which is commonly used in general tube structures. The PET can shrink due to heat shrinkage at a high temperature of 80°C or higher.

[0079] In one embodiment of the present invention, the tube structure provides a cold shrinkable jelly roll.

[0080] The normal temperature may be one temperature selected from 20°C to 27°C, for example, 22°C to 26°C, 24°C to 26°C, or 25°C.

[0081] Since the tube structure shrinks at room temperature, the time required to produce one product can be shortened, the process capacity can be improved, rework can be easily performed, and costs can be reduced, compared to a tube structure formed by heat shrinking at a high temperature of 80° C. or more. That is, since the tube structure shrinks at room temperature, a tube heating process for applying heat to the tube structure can be omitted, and the tube structure can be realized by a simplified process unlike the conventional process.

[0082] The tube structure may include a polyvinyl chloride (PVC+EVE) compound and shrink at room temperature.

[0083] One embodiment of the present invention provides a jelly roll, wherein the room temperature shrinkage rate of the tube structure is 30% or less.

[0084] The room temperature shrinkage rate means the degree of shrinkage at room temperature relative to 100% of the tube structure.

[0085] The cold shrinkage percentage of the tube structure may be 28% or less, 26% or less, 24% or less, 22% or less, or 20% or less.The cold shrinkage percentage of the tube structure may be 3% or more, 5% or more, 7% or more, 9% or more, or 11% or more.

[0086] When the above range is satisfied, the tube structure shrinks at room temperature, and compared to a tube structure formed by thermal shrinkage at a high temperature, the time required to produce one product can be shortened, the process capacity can be improved, reworkability is easy, and it is also advantageous in cost reduction.

[0087] In one embodiment of the present invention, a jelly roll is provided, wherein the tube structure comprises an insulating material.

[0088] The tube structure may have a dielectric strength of 14KV / mm and a dielectric constant of 9.0, the dielectric strength being measured according to the KSC2105 test method and the dielectric constant being measured according to the AS1977 test method.

[0089] Within this range, the tube structure is disposed to expose the positive electrode uncoated portion and the positive electrode current collector plate, and surround a side of the electrode assembly to which the battery can abuts, and one end of the electrode assembly perpendicular to the winding axis, thereby improving insulation quality.

[0090] Since the tube structure provided to surround the side of the electrode assembly and one end perpendicular to the winding axis of the electrode assembly contains an insulating material, problems such as wrinkles and lifting do not occur compared to when insulating tape is attached, so that the insulation quality is improved, the product production time is shortened, and the process capacity is improved. In addition, it is easy to insert into the battery can, making rework easy, and is advantageous in reducing costs.

[0091] In one embodiment of the present invention, a jelly roll is provided, wherein the thickness of the tube structure is set to 3 mm or less.

[0092] The thickness of the tube structure may be 2.5mm or less, 2mm or less, 1.5mm or less, or 1mm or less. The thickness of the tube structure may be 0.04mm or more, or 0.05mm or more.

[0093] When the above range is satisfied, it is advantageous for ensuring the capacity of the jelly roll including the tube structure of the present invention.

[0094] One embodiment of the present invention provides a secondary battery including a jelly roll according to the above-described embodiment; and a battery can housing the jelly roll, the battery can including an electrode terminal riveted through a through hole formed in the bottom of the battery can, and a gasket provided between the electrode terminal and an outer diameter of the through hole.

[0095] Referring to FIG. 2, there is shown a secondary battery 30 having a structure in which all electrical connections of the positive and negative terminals are made at the opposite side of one open side of a battery can 31, i.e., at the bottom 200 of the battery can.

[0096] Such a secondary battery 30 includes an electrode terminal 100 riveted through a through hole 300 formed in the bottom 200, and a gasket 400 provided between the electrode terminal 100 and the outer circumference of the through hole 300 to insulate the electrode terminal 100 from the battery can 31.

[0097] Such a secondary battery may be a cylindrical secondary battery, in which case a negative electrode terminal may be provided on the bottom 200 and the riveted electrode terminal 100 may be a positive electrode terminal.

[0098] In the electrode assembly 1, the positive electrode current collector 7 welded to the positive electrode uncoated portion 6 may be electrically connected to the riveted electrode terminal 100 via a through hole 300 formed in the bottom 200 of the battery can, and the exposed positive electrode uncoated portion 6 and the positive electrode current collector 7 of the electrode assembly 1 in contact with the battery can 31 may be insulated by the tube structure 10. As a result, the current applied to the battery may be stably increased, a high energy density may be realized, and a high-capacity and high-power secondary battery may be provided.

[0099] In one embodiment of the present invention, a secondary battery is provided, wherein the electrode terminal includes: a body portion inserted into the through hole; an external flange portion extending along one peripheral edge of the body portion exposed through the external surface of the bottom portion from the external surface; an internal flange portion extending toward the internal surface from the other peripheral edge of the body portion exposed through the internal surface of the bottom portion; and a flat portion provided on the inside of the internal flange portion.

[0100] The battery can according to the embodiment of the present invention may include an electrode terminal riveted to the bottom of the battery can. For example, the electrode terminal riveted to the bottom of the battery can may have a rivet structure.

[0101] Referring to FIG. 2 , the rivet structure of the electrode terminal 100 according to the embodiment may include a cylindrical battery can 31 having one side open, an electrode terminal 100 riveted through a through-hole 300 formed in a bottom 200 of the battery can, and a gasket 400 provided between the electrode terminal 100 and the outer diameter of the through-hole 300.

[0102] The battery can 31 is made of a conductive metal material. As an example, the battery can 31 may be made of a steel material, but the present invention is not limited thereto.

[0103] The electrode terminal 100 is made of a conductive metal material. As an example, the electrode terminal 100 may be made of aluminum, but the present invention is not limited thereto.

[0104] The gasket 400 may be made of a polymer resin having insulating properties and elasticity. For example, the gasket 400 may be made of polypropylene, polybutylene terephthalate, polyfluoroethylene, etc., but the present invention is not limited thereto.

[0105] Preferably, the electrode terminal 100 may include a body portion 110 inserted into the through hole 300, an external flange portion 120 extending along the external surface from one peripheral edge of the body portion 110 exposed through the external surface of the bottom portion 200 of the battery can, an internal flange portion 130 extending toward the internal surface from the other peripheral edge of the body portion 110 exposed through the internal surface of the bottom portion 200 of the battery can, and a flat portion 140 provided on the inside of the internal flange portion 130.

[0106] Preferably, the inner surfaces of the flat portion 140 and the bottom portion 200 of the battery can may be parallel to each other, where "parallel" means substantially parallel when observed with the naked eye.

[0107] According to an embodiment of the present invention, the rivet structure of the electrode terminal 100 can be formed using a caulking jig that moves up and down. First, a gasket 400 is placed in a through hole 300 formed in the bottom of a battery can, and a preform (not shown) of the electrode terminal 100 is inserted. The preform refers to the electrode terminal before being riveted.

[0108] Next, a caulking jig is inserted into the inner space of the battery can. The caulking jig has grooves and protrusions corresponding to the final shape of the electrode terminal 100 on the surface facing the preform in order to rivet the preform to form the electrode terminal 100.

[0109] The caulking tool is then moved downward and pressure molds the top of the preform, transforming the preform into a riveted electrode terminal 100 .

[0110] While the preform is pressurized by the caulking tool, the portion of the gasket 400 interposed between the outer flange portion 120 and the outer surface of the bottom of the battery can is elastically compressed and its thickness is reduced, thereby significantly improving the sealing and hermeticity between the riveted electrode terminal 100 and the battery can.

[0111] Preferably, gasket 400 is compressed sufficiently during the riveting process of the preform to provide the desired seal strength without being physically damaged.

[0112] As an example, when gasket 400 is made of polybutylene terephthalate, gasket 400 preferably has a compressibility of 50% or more at the point where it is compressed to its minimum thickness. The compressibility is the ratio of the change in thickness before and after compression to the thickness before compression.

[0113] As another example, if gasket 400 is made of polyfluoroethylene, gasket 400 preferably has a compressibility of 60% or greater at the point where it is compressed to its minimum thickness.

[0114] As another example, when gasket 400 is made of polypropylene, gasket 400 preferably has a compressibility of 60% or more at the point where it is compressed to its minimum thickness.

[0115] Preferably, the caulking jig is moved up and down at least twice, so that the pressure molding of the upper part of the preform can be performed in stages. That is, the preform can be deformed multiple times by pressure molding in stages. At this time, the pressure applied to the caulking jig can be increased in stages. As a result, the stress applied to the preform can be dispersed multiple times, so that the gasket 400 can be prevented from being damaged during the caulking process.

[0116] After the pressure molding of the preform using the caulking jig is completed, the caulking jig is separated from the battery can, whereby the rivet structure of the electrode terminal 100 according to the embodiment of the present invention can be obtained as shown in FIG.

[0117] According to the above-described embodiment, the caulking tool moves up and down inside the battery can to pressurize the upper part of the preform. In some cases, a rotary tool used in the prior art can be used to pressurize the preform.

[0118] However, the rotary rotation jig rotates at a certain angle with respect to the central axis of the battery can. Therefore, a rotary rotation jig with a large rotation radius may interfere with the inner wall of the battery can. In addition, if the depth of the battery can is large, the length of the rotary rotation jig is also long. In this case, the rotation radius of the end of the rotary rotation jig becomes large, and the preform may not be sufficiently pressurized. Therefore, pressurization using a caulking jig is more effective than the method using a rotary rotation jig.

[0119] The rivet structure of the electrode terminal 100 according to the embodiment of the present invention described above can be applied to the secondary battery 30.

[0120] As an example, the secondary battery 30 may include a battery can 31. The battery can 31 may be cylindrical. Its size may be a circular diameter of both ends of 30 mm to 55 mm and a height of 60 mm to 120 mm. Preferably, the circular diameter x height of the cylindrical battery can 31 may be 46 mm x 60 mm, 46 mm x 80 mm, 46 mm x 90 mm, or 46 mm x 120 mm.

[0121] Preferably, the cylindrical secondary battery may be, for example, a cylindrical secondary battery having a form factor ratio (defined as the diameter of the cylindrical secondary battery divided by its height, i.e., the ratio of the diameter (Φ) to the height (H)) of greater than about 0.4.

[0122] Here, the form factor refers to a value indicating the diameter and height of a cylindrical secondary battery. A cylindrical secondary battery 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 indicate the diameter of the cell, the next two digits indicate the height of the cell, and the final digit 0 indicates that the cross section of the cell is circular.

[0123] The secondary battery according to one embodiment of the present invention may be a cylindrical secondary battery having a substantially cylindrical cell shape with a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0124] A secondary battery according to another embodiment may be a cylindrical secondary battery having a substantially cylindrical cell shape with a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0125] Furthermore, the secondary battery according to another embodiment may be a cylindrical secondary battery having a substantially cylindrical cell with a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0126] A secondary battery according to still another embodiment may be a cylindrical secondary battery having a substantially cylindrical cell shape with a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0127] A secondary battery according to still another embodiment may be a cylindrical secondary battery having a substantially cylindrical cell shape with a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0128] A secondary battery according to still another embodiment may be a cylindrical secondary battery having a substantially cylindrical cell shape with a diameter of about 46 mm, a height of about 90 mm, and a form factor ratio of 0.511.

[0129] Conventionally, secondary batteries with a form factor ratio of about 0.4 or less have been used. That is, conventionally, for example, 18650 cells, 21700 cells, etc. have been used. In the case of an 18650 cell, its diameter is about 18 mm, its height is about 65 mm, and its form factor ratio is 0.277. In the case of a 21700 cell, its diameter is about 21 mm, its height is about 70 mm, and its form factor ratio is 0.300.

[0130] According to one embodiment of the present invention, the secondary battery includes a negative electrode terminal provided at a bottom of the battery can, and the riveted electrode terminal is a positive electrode terminal, and the positive electrode terminal is electrically connected to one end of the electrode assembly perpendicular to a winding axis.

[0131] According to one embodiment of the present invention, there is provided a secondary battery, wherein the electrode assembly further includes a positive current collector provided at one end of the electrode assembly perpendicular to the winding axis, and the positive terminal is electrically connected to the positive current collector.

[0132] According to one embodiment of the present invention, there is provided a secondary battery, wherein the tube structure includes a hole formed at the center of one end perpendicular to a winding axis of the electrode assembly, and the positive terminal and the positive current collector are electrically connected through the hole.

[0133] The current collector and tube structures in the secondary battery according to an embodiment of the present invention are the same as those described above in the electrode assembly.

[0134] In 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 may be any active material known in the art without any limitations.

[0135] Non-limiting examples of the positive electrode active material include conventional positive electrode active materials that can be used for the positive electrodes of conventional electrochemical elements, and in particular, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a lithium composite oxide that is a combination of these.

[0136] As an example, the positive electrode active material can be represented by the general chemical formula A[A x M y ]O 2+z (A includes at least one element selected from Li, Na, and K; M includes at least one element 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; x, y, z, and the stoichiometric coefficients of the components included in M ​​are selected such that the compound remains electrically neutral).

[0137] As another example, the positive electrode active material may be an alkali metal compound xLiM disclosed in US Pat. No. 6,677,082, US Pat. No. 6,680,143, etc. 1 O2-(1-x)Li2M 2 O3(M 1 contains at least one element having an average oxidation state of 3; M 2 contains at least one element having an average oxidation state of 4; 0≦x≦1).

[0138] As another example, the positive electrode active material may be represented by the general chemical formula LiA 1 xFe1-xM 2 yP1-yM 3 zO 4-z (M 1 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M3 contains a halogen group element selectively containing F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients of the components contained in a, x, y, z, M1, M2, and M3 are selected so that the compound maintains electrical neutrality), or 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].

[0139] Preferably, the positive electrode active material can contain primary particles and / or secondary particles formed by aggregation of primary particles.

[0140] As non-limiting examples 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 lithium-adsorbing substances such as other carbons can be used.

[0141] As an example, as the negative electrode active material, carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. can be used. 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, both low-crystalline carbon and high-crystalline carbon can be used.

[0142] Non-limiting examples of the positive electrode current collector include foils made of aluminum, nickel, or combinations thereof, and non-limiting examples of the negative electrode current collector include foils made of copper, gold, nickel or copper alloys, or combinations thereof.

[0143] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., either alone or in combination. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of a high melting point glass fiber, a polyethylene terephthalate fiber, etc.

[0144] At least one surface of the separator may include a coating layer of inorganic particles.

[0145] Alternatively, the separator itself may be made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound to a binder so that there is an interstitial volume between adjacent particles.

[0146] 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 be 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.

[0147] The electrolyte is A + B - In this case, the salt may have the structure: + Li + , Na + , K + and ions consisting of combinations of these. - 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 - The anion includes at least one anion selected from the group consisting of:

[0148] The electrolyte can be 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, and mixtures thereof.

[0149] Another embodiment of the present invention provides a battery pack including at least one of the above-described secondary batteries.

[0150] The cylindrical secondary battery according to the above-described embodiment can be used to manufacture a battery pack.

[0151] FIG. 5 is a diagram showing a schematic configuration of a battery pack including a secondary battery according to an embodiment of the present invention.

[0152] 5, a battery pack 40 according to an embodiment of the present invention includes an assembly of electrically connected cylindrical secondary batteries, and a pack housing 50 that accommodates the assembly. The cylindrical secondary battery is the secondary battery 30 according to the above-described embodiment. For convenience of illustration, components such as a bus bar for electrically connecting the cylindrical secondary battery 30, a cooling unit, and external terminals are omitted in the drawings.

[0153] Another embodiment of the present invention provides a vehicle including at least one battery pack as described above.

[0154] The battery pack can be installed in 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.

[0155] FIG. 6 is a diagram for explaining an automobile including the battery pack of FIG.

[0156] 6, an automobile 60 according to an embodiment of the present invention includes a battery pack 40 according to an embodiment of the present invention. The automobile operates by receiving power from the battery pack 40 according to an embodiment of the present invention.

[0157] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the scope of the claims which will be described later. [Explanation of symbols]

[0158] 1...electrode assembly 2. Side of electrode assembly 3. One end of the electrode assembly perpendicular to the winding shaft 4. The other end perpendicular to the winding shaft of the electrode assembly 6 Positive electrode uncoated area 7 Positive current collector plate 10. Tube structure 11...Tube structure hole 12A: Area of ​​the tube structure provided at the end perpendicular to the winding shaft of the electrode assembly 12W: Width of the tube structure at the end perpendicular to the winding axis of the electrode assembly 20 Jelly Roll 30...Secondary battery 31 Battery can 40 Battery pack 50···Pack Housing 60 Automobiles 100...electrode terminal 110 Body 120 External flange part 130 Internal flange portion 140...Flat area 200 ···Bottom of battery can 300 ... through hole 400 ···Gasket C Winding shaft

Claims

1. An electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and A tube structure provided so as to surround at least a portion of a side surface of the electrode assembly and at least a portion of one end of the electrode assembly perpendicular to the winding axis.

1. A jelly roll comprising: The tubular structure is provided to include a hole formed in the center of one end perpendicular to the winding axis of the electrode assembly.

2. At least one of the positive electrode and the negative electrode includes a current collector and an electrode active material layer provided on the current collector, the current collector including a non-coated portion on which the electrode active material layer is not provided, At least a portion of the uncoated portion is exposed on a side surface of the electrode assembly, The jelly roll of claim 1 , wherein the tube structure is disposed to surround a plain portion of a side surface of the electrode assembly.

3. The electrode assembly further includes a current collector plate, 3. The jelly roll of claim 1, wherein the current collector is located between the tube structure and the electrode assembly, or at the other end of the electrode assembly perpendicular to the winding axis.

4. 3. The jelly roll of claim 1, wherein the tube structure does not extend to an end portion opposite to the end portion perpendicular to the winding axis of the electrode assembly.

5. The tube structure is provided to extend from an outer circumferential surface of one end of the electrode assembly perpendicular to the winding axis to the hole, 3. The jelly roll according to claim 1, wherein an area of ​​the tube structure provided at one end of the electrode assembly perpendicular to the winding shaft is 50% or less of an area of ​​the one end of the electrode assembly perpendicular to the winding shaft, the area being 100%.

6. The tube structure is provided to extend from an outer circumferential surface of one end of the electrode assembly perpendicular to the winding axis to the hole, 3. The jelly roll according to claim 1, wherein the width of the tube structure provided at one end perpendicular to the winding axis of the electrode assembly is 30% or less of a diameter of the one end perpendicular to the winding axis of the electrode assembly.

7. 3. The jelly roll of claim 1 or 2, wherein the tube structure comprises an elastic material.

8. 3. The jelly roll of claim 1 or 2, wherein the tube structure comprises a polyvinyl chloride type (PVC+EVE) compound.

9. 3. The jelly roll of claim 1 or 2, wherein the tube structure shrinks at room temperature.

10. 3. The jelly roll according to claim 1, wherein the room temperature shrinkage rate of the tube structure is 30% or less.

11. 3. The jelly roll of claim 1 or 2, wherein the tube structure comprises an insulating material.

12. 3. The jelly roll of claim 1, wherein the thickness of the tube structure is set to 3 mm or less.

13. A jelly roll according to claim 1 or 2; and A battery can containing the jelly roll A secondary battery comprising: The battery can includes an electrode terminal riveted through a through hole formed in a bottom of the battery can, and a gasket provided between the electrode terminal and an outer diameter of the through hole.

14. The electrode terminal has a body portion inserted into the through hole; an external flange portion extending along the exterior surface from one peripheral edge of the body portion exposed through the exterior surface of the bottom portion; an internal flange portion extending from the other peripheral edge of the body portion exposed through the internal surface of the bottom portion toward the internal surface; and A flat portion provided on the inside of the internal flange portion The secondary battery according to claim 13 .

15. The secondary battery includes a negative electrode terminal provided at a bottom of the battery can, and the riveted electrode terminal is a positive electrode terminal; The secondary battery of claim 13 , wherein the positive terminal is electrically connected to one end of the electrode assembly perpendicular to a winding axis.

16. The electrode assembly further includes a positive electrode current collector provided at one end perpendicular to the winding axis of the electrode assembly, The secondary battery of claim 15 , wherein the positive terminal is electrically connected to the positive current collector plate.

17. The secondary battery according to claim 16 , wherein the positive terminal and the positive current collector are electrically connected through a hole in the tube structure.

18. A battery pack comprising at least one secondary battery according to claim 13.

19. 20. A vehicle comprising at least one battery pack according to claim 18.

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