Fixing structure of electrode terminal, and battery, battery pack, and vehicle including same

Abstract

To provide a fixing structure of an electrode terminal, and a battery, a battery pack, and a vehicle including the same.SOLUTION: A fixing structure of an electrode terminal includes: a battery housing having an open end at one side and a bottom with a perforation hole at the other side; an electrode terminal fixed to the bottom; and a terminal gasket interposed between the electrode terminal and the bottom. The electrode terminal includes: a neck portion having a cross section smaller than a cross section of the perforation hole and inserted into the perforation hole; a head portion connected to one end of the neck portion and configured to have a cross section larger than the cross section of the perforation hole and extend along one surface of the bottom; a protrusion connected to the other end of the neck portion and configured to extend along an axial direction of the battery housing from the other surface of the bottom; a diameter-enlarged portion configured to extend in a centrifugal direction from the protrusion; and a front end surface prepared at an axial end of the protrusion. The diameter-enlarged portion is a fastening member physically coupled to an outer circumference of the protrusion.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a fixing structure of an electrode terminal, a battery including the same, a battery pack, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2021-0163457 filed on November 24, 2021, and Korean Patent Application No. 10-2022-0083905 filed on July 7, 2022, and all of the contents disclosed in the specifications and drawings of the applications are incorporated into this application.

Background Art

[0003] Secondary batteries with high applicability for each product group and having electrical characteristics such as high energy density are widely applied not only to portable devices but also to electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), etc. driven by an electric drive source. Hereinafter, an electric vehicle is used in a concept including EVs, HEVs, PHEVs, etc.

[0004] Such secondary batteries are attracting attention as a new energy source for improving energy efficiency because they are not only environmentally friendly in that they significantly reduce the use of fossil fuels but also produce no by-products due to energy use.

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

[0006] On the other hand, as types of secondary batteries, cylindrical, prismatic, and pouch-type batteries are known. In the case of a cylindrical battery, a separator, which is an insulator, is interposed between the positive electrode and the negative electrode, and this is wound up to form a jelly-roll type electrode assembly, and this is inserted into the inside of a battery housing together with an electrolyte to constitute a battery. And strip-shaped electrode tabs are connected to the plain portions of the positive electrode and the negative electrode respectively, and the electrode tabs electrically connect between the electrode assembly and the electrode terminals exposed to the outside. For reference, the positive electrode terminal is the cap of a sealing body that seals the opening of the battery housing, and the negative electrode terminal is the battery housing.

[0007] However, according to such a conventional cylindrical battery having such a structure, since current is concentrated on the strip-shaped electrode tabs coupled to the positive electrode plain portion and / or the negative electrode plain portion, there is a problem that the resistance is large, heat generation is much, and the current collection efficiency is not good.

[0008] In small cylindrical batteries having a form factor of 1865 or 2170, the problems of large resistance and heat generation do not occur. However, when increasing the form factor for applying the cylindrical battery to an electric vehicle, a problem may occur that the cylindrical battery catches fire while generating a large amount of heat around the electrode tabs during the rapid charging process.

[0009] To solve such problems, a cylindrical battery (so-called tab-less cylindrical battery) is presented, which is designed such that a positive electrode non-coated part and a negative electrode non-coated part are respectively located at the upper and lower ends of a jelly roll type electrode assembly, and a current collector is welded to such non-coated parts to have a structure with improved current collection efficiency.

[0010] Figs. 1 to 3 are diagrams showing the manufacturing process of a tab-less cylindrical battery. Fig. 1 shows the structure of the electrode, Fig. 2 shows the electrode winding process, and Fig. 3 shows the process in which the current collector is welded to the folded surface of the non-coated part. Fig. 4 is a cross-sectional view of the tab-less cylindrical battery cut in the longitudinal direction (Y-axis).

[0011] Referring to Figs. 1 to 4, the positive electrode 10 and the negative electrode 11 have a structure in which the active material 21 is coated on the sheet-like current collector 20, and include a non-coated part 22 on one long side along the winding direction X.

[0012] The electrode assembly A is manufactured by sequentially laminating the positive electrode 10 and the negative electrode 11 together with two separator films 12 as shown in Fig. 2, and then winding them in one direction (X-axis direction). At this time, the non-coated part of the positive electrode 10 and the non-coated part of the negative electrode 11 are arranged in opposite directions to each other.

[0013] After the winding process, the non-coated part 10a of the positive electrode 10 and the non-coated part 11a of the negative electrode 11 are bent toward the core side. Then, the current collectors 30 and 31 are respectively welded and joined to the non-coated parts 10a and 11a.

[0014] Separate electrode tabs are not connected to the positive electrode non-coated part 10a and the negative electrode non-coated part 11a, and the current collectors 30 and 31 are connected to external electrode terminals. Since the current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly A (refer to the arrow in Fig. 3), there is an advantage that the resistance of the battery can be reduced. This is because the resistance is inversely proportional to the cross-sectional area of the path through which the current flows.

[0015] However, when the form factor of the cylindrical battery increases and the charging current during rapid charging becomes large, the problem of heat generation occurs again even in the tabless cylindrical battery.

[0016] Specifically, as shown in FIG. 4, the conventional tabless cylindrical battery 40 includes a battery housing 41 and a sealing body 42. The sealing body 42 includes a cap 42a, a sealing gasket 42b, and a connecting plate 42c. The sealing gasket 42b is fixed by a crimping portion 43 while covering the periphery of the cap 42a. Further, the electrode assembly A is fixed in the battery housing 41 by a beading portion 44 to prevent vertical movement.

[0017] Normally, the positive electrode terminal is the cap 42a of the sealing body 42, and the negative electrode terminal is the battery housing 41. Therefore, the current collector 30 coupled to the plain portion 10a of the positive electrode 10 is electrically connected to the connecting plate 42c attached to the cap 42a through a strip-shaped lead 45. Also, the current collector 31 coupled to the plain portion 11a of the negative electrode 11 is electrically connected to the bottom of the battery housing 41.

[0018] The insulator 46 covers the current collector 30 to prevent the battery housing 41 with a different polarity from coming into contact with the plain portion 10a of the positive electrode 10 and causing a short circuit.

[0019] When the current collector 30 is connected to the connecting plate 42c, a strip-shaped lead 45 is used. The lead 45 is separately attached to the current collector 30 or integrally manufactured with the current collector 30. However, since the lead 45 is in a thin strip shape, its cross-sectional area is small, and when a rapid charging current flows, a large amount of heat is generated. Also, the excessive heat generated in the lead 45 is transmitted to the electrode assembly A side and causes the separator 12 to contract, which can cause an internal short circuit, which is the main cause of thermal runaway.

[0020] That is, according to the structure of the conventional cylindrical battery, the current collector 31 facing the bottom of the battery housing 41 is in direct contact with the bottom of the battery housing 41. Therefore, a sufficiently large cross-sectional area is ensured in the current moving direction, and there are no problems such as overheating. On the other hand, the current collector 30 connected to the sealing body 42 crimped to the opening of the battery housing 41 is connected to the sealing body 42 through the strip-shaped lead 45, which inevitably causes the above-mentioned overheating problem.

[0021] Also, in the manufacturing process, the lead 45 occupies a considerable installation space inside the battery housing 41. Therefore, the cylindrical battery 40 including the lead 45 has low space efficiency and is limited in increasing the energy density.

[0022] Furthermore, in order to connect the conventional tabless cylindrical batteries 40 in series and / or in parallel, bus bar components must be connected to the cap 42a of the sealing body 42 and the bottom surface of the battery housing 41, resulting in a decrease in space efficiency. The battery pack mounted on an electric vehicle includes hundreds of cylindrical batteries 40. Therefore, the inefficiency of electrical wiring also causes considerable inconvenience during the assembly process of the electric vehicle and during the maintenance of the battery pack.

[0023] Also, the crimping portion 43 provided on the peripheral side of the sealing body 42 is a site having a negative polarity and is exposed at the upper part of the cylindrical battery 40. In FIG. 4, the upper part of the crimping portion 43 is shown large, but actually the area of the crimping portion 43 exposed at the upper part is very small compared to the area of the sealing body 42. Therefore, in order to stably connect the bus bar components, the sealing body 42 crimped to the opening of the battery housing 41 and the bottom of the battery housing 41 will be used. Summary of the Invention Problems to be Solved by the Invention

[0024] The present invention was devised to solve the above-described problems, and aims to reduce the internal resistance of a cylindrical battery and increase the energy density by improving the structure of the electrode terminals of the cylindrical battery to increase the space efficiency within the battery housing.

[0025] Another object of the present invention is to improve the problem of internal heat generation that occurs during rapid charging by improving the structure of the electrode terminals of the cylindrical battery to expand the cross-sectional area of the current path.

[0026] Yet another object of the present invention is to provide a cylindrical battery with an improved structure that enables electrical wiring work for series and / or parallel connection of cylindrical batteries to be performed on one side of the cylindrical battery.

[0027] Still another object of the present invention is to provide a battery pack manufactured using a cylindrical battery having an improved structure, and an automobile including the same.

[0028] The technical problems of the present invention are not limited to the above-described objects, and other objects and advantages of the present invention not mentioned will be understood from the following description and will be more clearly understood from the embodiments of the present invention. Also, the objects and advantages of the present invention can be realized by the means and combinations thereof shown in the claims.

Means for Solving the Problems

[0029] To achieve the above object, a fixing structure of an electrode terminal according to an aspect of the present invention includes a battery housing having an open end portion on one side and a bottom portion having a through hole formed on the other side, an electrode terminal fixed to the bottom portion, and a terminal gasket interposed between the electrode terminal and the bottom portion.

[0030] The electrode terminal includes a neck portion inserted into the through hole and having a cross section smaller than that of the through hole, a head portion connected to one end of the neck portion and having a cross section larger than that of the through hole and extending along one surface of the bottom portion, a protruding portion connected to the other end of the neck portion and extending along the axial direction of the battery housing from the other surface of the bottom portion, a diameter-expanded portion extending in the centrifugal direction from the protruding portion, and a tip surface provided at the axial end of the protruding portion. The diameter-expanded portion is a fastening member physically coupled to the outer peripheral surface of the protruding portion.

[0031] A fastening groove is provided on the outer peripheral surface of the protruding portion, formed along the circumferential direction and recessed in the centripetal direction, and the fastening member can be fitted and fixed in the fastening groove.

[0032] The fastening groove has a shape of male screw threads, and the fastening member can be a nut formed with female screw threads that are fastened to the male screw threads.

[0033] The fastening groove is an O-shaped groove, and the fastening member can be a C-shaped ring fitted into the O-shaped groove.

[0034] The surface of the fastening member facing the bottom portion may include a side wall surface that gradually becomes farther from the bottom portion toward the outer side in the radial direction.

[0035] When the fastening member is coupled to the fastening groove, the side wall surface can crimp the terminal gasket toward the bottom portion of the battery housing.

[0036] The fixing structure of the electrode terminal may further include a first sealing coating layer formed at the interface between the terminal gasket and the bottom portion of the battery housing.

[0037] The first sealing coating layer may include a silicone resin, a silicone acrylate, or a polyamideimide.

[0038] The fixing structure of the electrode terminal may further include a second sealing coating layer that covers the external exposure interface between the fastening member and the terminal gasket.

[0039] Optionally, the second sealing coating layer may cover the external exposure interface between the terminal gasket and the bottom.

[0040] The second sealing coating layer may include a silicone resin, a silicone acrylate, or a polyamideimide.

[0041] The tip surface may further protrude in the axial direction of the battery housing from the enlarged diameter portion with respect to the bottom surface of the battery housing.

[0042] The tip surface may include a flat portion with a flat surface.

[0043] The fastening member may include a first section that gradually moves away from the bottom of the battery housing as it extends in the centrifugal direction from the protruding portion.

[0044] In the first section, the angle formed by the surface of the fastening member facing the bottom and the bottom may be more than 0° and 60° or less.

[0045] The diameter of the cross-section of the enlarged diameter portion cut in a direction perpendicular to the central axis of the battery housing may be larger than the diameter of the through hole.

[0046] The diameter of the cross-section of the enlarged diameter portion cut in a direction perpendicular to the central axis of the battery housing may gradually increase as it moves away from the bottom of the battery housing.

[0047] A portion of the terminal gasket interposed between the head portion and the bottom of the battery housing may be in a state of being crimped.

[0048] To achieve the above problems, a battery according to another aspect of the present invention includes a fixing structure of an electrode terminal including at least one of the above-described features.

[0049] The battery includes: an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, and which includes a plain portion of the first electrode and a plain portion of the second electrode that extend from both side ends and are exposed outside the separator; a battery housing having an open end on one side and housing the electrode assembly through the open end and being electrically connected to the first electrode; and an electrode terminal that is attached through a through hole formed in the bottom of the battery housing without contacting an inner wall of the through hole and is electrically connected to the second electrode. The electrode terminal has a neck portion inserted into the through hole and having a cross section smaller than that of the through hole, a head portion connected to one side end of the neck portion and having a cross section larger than that of the through hole and extending along one surface of the bottom, a protruding portion connected to the other side end of the neck portion and extending along the axial direction of the battery housing from the other surface of the bottom, a diameter-expanded portion extending in a centrifugal direction from the protruding portion, and a tip surface provided at an axial end of the protruding portion. The diameter-expanded portion is an electrode terminal that is a fastening member physically coupled to an outer peripheral surface of the protruding portion; a terminal gasket interposed between the electrode terminal and the through hole; and a sealing body that seals the open end of the battery housing in an insulating manner from the battery housing.

[0050] The battery housing includes a beading portion that is pushed into the inside of the battery housing in a region adjacent to the open end, and the sealing body may include a non-polar cap and a sealing gasket interposed between a peripheral edge of the cap and the open end of the battery housing.

[0051] The battery housing may further include a crimping portion that extends and is bent inside the battery housing and wraps and fixes the peripheral edge of the cap together with the sealing gasket.

[0052] The battery further includes a first current collector coupled to the non-patterned portion of the first electrode, and at least a part of the periphery of the first current collector that does not contact the non-patterned portion of the first electrode can be interposed between the beading portion and the sealing gasket and fixed by the crimping portion.

[0053] At least a part of the periphery of the first current collector can be fixed to the inner peripheral surface of the beading portion adjacent to the crimping portion through welding.

[0054] The battery further includes a second current collector coupled to the non-patterned portion of the second electrode, and at least a part of the second current collector can be welded to the tip surface of the electrode terminal.

[0055] The battery may further include insulators interposed between the second current collector and the inner surface of the bottom of the battery housing, and between the inner peripheral surface of the side wall of the battery housing and the electrode assembly.

[0056] The battery is cylindrical, and the ratio of the form factor obtained by dividing the diameter of the battery by the height of the battery can be greater than 0.4.

[0057] The AC resistance measured between the electrode terminal of the battery and the outer surface of the bottom of the battery housing can be 4 mΩ or less.

[0058] The above problems can also be achieved by a battery pack including a plurality of the above-described batteries and an automobile including the same.

Advantages of the Invention

[0059] According to one aspect of the present invention, by improving the structure of the electrode terminal of the cylindrical battery so that leads can be omitted and increasing the space efficiency in the battery housing, the internal resistance of the cylindrical battery can be reduced and the energy density can be increased.

[0060] Further, according to one aspect of the present invention, by improving the structure of the electrode terminal of the cylindrical battery so that the electrode terminal and the current collector can be directly connected and expanding the cross-sectional area of the current path, the problem of internal heat generation during rapid charging can be improved.

[0061] Further, according to one aspect of the present invention, by arranging all two electrodes at the bottom which is one side of the cylindrical battery, the electrical wiring work for the series and / or parallel connection of the cylindrical battery can be performed on one side of the cylindrical battery.

[0062] Further, according to one aspect of the present invention, a battery pack manufactured using a cylindrical battery having an improved structure, and an automobile including the same can be provided.

[0063] The specific effects of the present invention together with the above-described effects will be described later by citing specific matters for carrying out the invention.

Brief Description of Drawings

[0064]

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Mode for Carrying Out the Invention

[0065] The objectives, features, and advantages of the present invention will be described in detail below with reference to the accompanying drawings, so that those with ordinary knowledge in the technical field to which the present invention pertains will be able to easily implement the technical idea of the present invention. In the description of the present invention, if it is determined that a specific description of related known technologies may obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals mean the same or similar components.

[0066] Terms such as first and second are used to indicate various components, but these components are not limited by such terms. These terms are merely used to distinguish one component from another, and unless otherwise specified, the first component may also be the second component.

[0067] Throughout the specification, unless otherwise specified, each component may be singular or plural.

[0068] Hereinafter, when any configuration is arranged "above (or below)" a component or "on (or under)" a component, it means not only that any configuration is arranged in contact with the upper surface (or lower surface) of the component, but also that other configurations may be interposed between the component and any configuration arranged above (or below) the component.

[0069] Also, when a component is "connected", "coupled", or "joined" to another component, it includes not only the case where the components are directly connected or joined to each other, but also the case where other components are "interposed" between the components, or the case where each component is "connected", "coupled", or "joined" through another component.

[0070] In addition, the singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "including" are not necessarily construed to include all of the many components or many steps described in the specification, and some of the components or steps may not be included, and additional components or steps may also be included.

[0071] Throughout the specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or more and D or less unless otherwise specified.

[0072] For convenience of explanation, in this specification, the direction along the length direction of the winding axis of the electrode assembly wound in a jelly roll shape is referred to as the axial direction (Y-axis). Also, the direction surrounding the winding axis is referred to as the circumferential direction or the outer circumferential direction (X-axis direction). Further, the direction approaching or moving away from the winding axis is referred to as the radial direction or the radial direction (Z-axis direction). Among these, the direction approaching the winding axis in particular is referred to as the centripetal direction, and the direction moving away from the winding axis is referred to as the centrifugal direction.

[0073] Hereinafter, desirable embodiments of the present invention will be described with reference to the accompanying drawings.

[0074] The fixing structure of the electrode terminal 50 according to the present invention is applied to the structure of the cylindrical battery housing H.

[0075] The cylindrical battery housing H may include a cylindrical side wall 51 and a bottom 52 connected to an end of the side wall 51. Thereby, the cylindrical battery housing H may have a structure in which one side is open and the other side is closed by the bottom 52.

[0076] The electrode assembly 71 may be inserted into the battery housing H through the open side of the battery housing H, and may be inserted until the tip of the electrode assembly 71 (the end of the electrode assembly inserted first) reaches the bottom 52 of the battery housing H.

[0077] A through hole 53 is formed in the bottom 52 of the battery housing H.

[0078] The bottom 52 includes a first surface 52a and a second surface 52b facing each other, and the through hole 53 is a hole formed through the bottom 52 so that a first space facing the first surface 52a and a second space facing the second surface 52b communicate with each other.

[0079] The first surface 52a may be a surface exposed to the outside of the battery housing H, and thus the first space may be an external space of the battery housing H. The second surface 52b may be a surface facing the inside of the battery housing H, and thus the second space may be an internal space of the battery housing H.

[0080] On the other hand, the second surface 52b may be a surface exposed to the outside of the battery housing H, and the first surface 52a may be a back surface facing the inside of the battery housing H. Of course, in this case, the second space becomes the external space of the battery housing H, and the first space becomes the internal space of the battery housing H.

[0081] The first surface 52a and the second surface 52b respectively correspond to the outer surface and the inner surface of the bottom 52 of the battery housing H.

[0082] The through hole 53 may be provided near the center of the bottom 52 of the battery housing H.

[0083] Before accommodating the electrode assembly 71 in the battery housing H, first, the electrode terminal 50 is inserted into the through hole 53 to fix the electrode terminal 50 to the bottom 52 of the battery housing H.

[0084] As an example, the electrode terminal 50 may be fixed by a plastic working portion 50c1 formed by plastic working. Such plastic working may include riveting, caulking, and the like.

[0085] As another example, the electrode terminal 50 can be fixed through a separate fastening member (50c2 in FIG. 10 or 50c3 in FIG. 14). Such fastening members 50c2, 50c3 can include nuts, snap rings, and the like.

[0086] As shown in FIG. 6, the electrode terminal 50 can include a neck portion 50a having a cross-section smaller than that of the through-hole 53, and a head portion 50b provided at one end of the neck portion 50a and having a cross-section larger than that of the through-hole 53. A protruding portion 50e having a cross-section smaller than that of the through-hole 53 is provided at the other end of the neck portion 50a.

[0087] After inserting the protruding portion 50e of the electrode terminal 50 through the through-hole 53 from the first surface 52a side of the bottom 52 of the battery housing H, the periphery of the protruding portion 50e is plastically processed on the second surface 52b side of the bottom 52 of the battery housing H to form a plastically processed portion 50c1, or a fastening member 50c2 (or 50c3 in FIG. 14) can be physically fixed to the protruding portion 50e.

[0088] The plastically processed portion 50c1 or the fastening members 50c2, 50c3 constitute an enlarged diameter portion E that expands the cross-sectional area of the protruding portion 50e. Thereby, the cross-section of the protruding portion 50e becomes larger than that of the through-hole 53, and the electrode terminal 50 is fitted and fixed in the through-hole 53 to maintain the fixed state.

[0089] The electrode terminal 50 is inserted through the through-hole 53 provided in the bottom 52 from the outside of the battery housing H, and the protruding portion 50e can be plastically processed inside the battery housing H, or fastening members 50c2, 50c3 can be fixed to the protruding portion 50e. Thereby, the head portion 50b of the electrode terminal 50 is exposed outside the battery housing H, and the protruding portion 50e of the electrode terminal 50 can be disposed inside the battery housing H.

[0090] As an alternative, the electrode terminal 50 is inserted through a through hole 53 provided in the bottom portion 52 from inside the battery housing H, and a protruding portion 50e may be plastically processed outside the battery housing H, or fastening members 50c2 and 50c3 may be fixed to the protruding portion 50e. Thereby, the head portion 50b of the electrode terminal 50 is disposed inside the battery housing H, and the protruding portion 50e of the electrode terminal 50 may be exposed outside the battery housing H.

[0091] The surface (the surface exposed in the axial direction) of the head portion 50b of the electrode terminal 50 may include a flat region. The flat region can provide a connection surface such as a bus bar.

[0092] In one example, the cross section of the protruding portion 50e of the electrode terminal 50 may be expanded by riveting.

[0093] The protruding portion 50e of the electrode terminal 50 may include a plastically processed portion 50c1 formed by plastic deformation by riveting and a tip surface 50d provided at the tip of the protruding portion 50e.

[0094] The plastically processed portion 50c1 may constitute a diameter-expanded portion E.

[0095] The tip surface 50d may be disposed on the centripetal side (the inner side in the radial direction) rather than the plastically processed portion 50c1.

[0096] The tip surface 50d may include a flat portion D with a flat surface.

[0097] The tip surface 50d may form an overall flat flat portion D.

[0098] The tip surface 50d may be a surface that was already formed before the riveting process. That is, the tip surface 50d may be a region that is not deformed by the riveting process.

[0099] The tip surface 50d may include a surface that protrudes further in the axial direction than the diameter-expanded portion E.

[0100] The plastic working part 50c1 may include a first section 501c that gradually moves away from the bottom 52 of the battery housing H as it extends in the centrifugal direction from the protruding part 50e.

[0101] In the first section 501c, the angle formed by the surface of the plastic working part 50c1 facing the bottom 52 with the bottom 52 may be more than 0° and not more than 60°.

[0102] In one form, as shown in FIG. 6, the plastic working part 50c1 may consist only of the first section 501c. In another form, as shown in FIG. 9, the plastic working part 50c1 may be arranged on the centrifugal side of the first section 501c and may further include a second section 502c connected to the first section 501c. The second section 502c may gradually approach the bottom 52 of the battery housing H as it extends in the centrifugal direction.

[0103] In the second section 502c, the angle Φ formed by the surface of the plastic working part 50c1 facing the bottom 52 with the bottom 52 may be more than 0° and not more than 30°.

[0104] A groove part 55 recessed in the axial direction may be provided between the plastic working part 50c1 and the tip surface 50d. The groove part 55 may be in a closed loop shape surrounding the tip surface 50d in the circumferential direction.

[0105] Desirably, the groove part 55 may have a cross-sectional structure of an asymmetric groove. That is, the side wall surface 55a of the flat part D and the side wall surface 55b of the plastic working part 50c1 may not be parallel.

[0106] When the upper part of the protruding part 50e is plastically deformed into the diameter-expanded part E through riveting, the groove part 55 prevents the external force applied for plastic deformation from affecting the flat part D. Therefore, the dimensions and shape of the flat part D can be maintained even after riveting.

[0107] The side wall surface 55a connecting the bottom of the groove portion 55 and the flat portion D may be perpendicular to the plane including the flat portion D. Thereby, the area of the flat region of the flat portion D can be ensured to the maximum extent.

[0108] The side wall surface 55b of the plastic working portion 50c1 facing the side wall surface 55a of the flat portion D may form an inclined surface.

[0109] Preferably, the thickness of the diameter-expanded portion E may decrease as it gets farther from the protruding portion 50e.

[0110] In another form, the cross section of the protruding portion 50e of the electrode terminal 50 may be expanded by the physical connection of the fastening members 50c2 and 50c3.

[0111] Referring to FIG. 10, a fastening groove 50g extending along the circumferential direction may be provided on the outer peripheral surface of the protruding portion 50e of the electrode terminal 50. The fastening groove 50g may have a groove shape in which the cross section of the protruding portion 50e decreases. That is, the fastening groove 50g may be in a form recessed in the centripetal direction from the outer peripheral surface of the protruding portion 50e.

[0112] Referring to FIG. 11, by fitting and fixing the fastening member 50c2 into the fastening groove 50g, the protruding portion 50e is integrated with the fastening member 50c2, and thereby the cross section expands in the upper region of the protruding portion 50e. That is, after being fastened to the protruding portion 50e, the fastening member 50c2 may constitute the diameter-expanded portion E of the protruding portion 50e. In one example, the fastening groove 50g is an O-shaped groove, and the fastening member 50c2 may be a C-shaped ring fitted into the O-shaped groove.

[0113] Referring to FIG. 14, the fastening groove 50g may have a shape of a male thread, and the fastening member 50c3 may be a nut formed with a female thread.

[0114] The surfaces of the fastening members 50c2 and 50c3 facing the bottom 52 of the battery housing H may include a shape that gradually gets farther from the bottom 52 toward the outer side in the radial direction.

[0115] Referring to FIGS. 11 and 14, the tip surface 50d of the protruding portion 50e has a flat flat portion D, and the flat portion D can maintain its dimensions and shape without being affected by the fastening of the fastening members 50c2 and 50c3.

[0116] A terminal gasket 54 may be interposed between the electrode terminal 50 and the bottom 52 of the battery housing H.

[0117] The terminal gasket 54 may be interposed between the head portion 50b of the electrode terminal 50 and the bottom 52, between the neck portion 50a of the electrode terminal 50 and the inner peripheral surface of the through hole 53, and between the enlarged diameter portion E of the protruding portion 50e of the electrode terminal 50 and the bottom 52. Thereby, the terminal gasket 54 can insulate the electrode terminal 50 and the bottom 52, and can provide the air tightness of the battery housing H.

[0118] The side wall surface (the surface facing the bottom 52) of the plastic working portion 50c1 or the fastening members 50c2 and 50c3 further pulls the head portion 50b toward the first surface 52a side of the bottom 52 while crimping the terminal gasket 54. Thereby, the portion of the terminal gasket 54 interposed between the head portion 50b and the first surface 52a of the bottom 52 is strongly crimped.

[0119] Also, the side wall surface (the surface facing the bottom 52) of the plastic working portion 50c1 or the fastening members 50c2 and 50c3 strongly crimps the terminal gasket 54 at the corner portion where the inner peripheral surface of the through hole 53 and the second surface 52b of the bottom 52 are connected.

[0120] Referring to FIGS. 12 and 15, the fixing structure of the electrode terminal 50 according to the embodiment of the present invention may include a first sealing coating layer f1 formed between the terminal gasket 54 and the bottom 52 of the battery housing H. The first sealing coating layer f1 is interposed between the terminal gasket 54 and the bottom 52 of the battery housing H and can improve the sealing performance of the terminal gasket 54.

[0121] Referring to FIGS. 13 and 16, the fixing structure of the electrode terminal 50 according to the embodiment of the present invention may include a second sealing coating layer f2 that covers the external exposure interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the external exposure interface between the fastening members 50c2, 50c3 and the terminal gasket 54. Similar to the first sealing coating layer f1, the second sealing coating layer f2 can improve the sealing performance of the terminal gasket 54.

[0122] It should be understood that in the present invention, the first sealing coating layer f1 and / or the second sealing coating layer f2 are not essential elements but optional elements.

[0123] The first sealing coating layer f1 and / or the second sealing coating layer f2 may be made of a material having excellent sealing properties and resistance to electrolytes. As the material of the sealing coating layer (the first sealing coating layer f1, the second sealing coating layer f2), silicone resin, silicone acrylate or polyamideimide may be used, but the present invention is not limited thereto.

[0124] Hereinafter, embodiments of the present invention will be described in more detail.

[0125] The cylindrical battery according to the first embodiment of the present invention may include an electrode terminal riveted to the bottom of the battery housing.

[0126] FIG. 5 is a cross-sectional view showing the riveting structure of the electrode terminal 50 according to the embodiment of the present invention, FIG. 6 is an enlarged cross-sectional view showing only the electrode terminal 50, and FIG. 7 is an enlarged cross-sectional view of the portion indicated by the dashed-dotted circle.

[0127] Referring to FIGS. 5 to 7, the riveting structure of the electrode terminal 50 according to the present embodiment may include a cylindrical battery housing H with one side open, an electrode terminal 50 riveted through a through hole 53 formed in the bottom 52 of the battery housing H, and a terminal gasket 54 interposed between the electrode terminal 50 and the through hole 53.

[0128] The battery housing H is made of a conductive metal material. In one example, the battery housing H may be made of steel or aluminum material, but the present invention is not limited thereto. The battery housing H includes a cylindrical side wall 51 and a bottom 52 connected to an end of the side wall. The bottom 52 may be integrally formed with the side wall 51. For example, the battery housing H may be formed by pressing and drawing a sheet metal to integrally form the side wall 51 and the bottom 52.

[0129] The through hole 53 formed in the bottom 52 may be manufactured by punching the bottom 52 after forming the side wall 51 and the bottom 52.

[0130] The electrode terminal 50 is made of a conductive metal material. In one example, the electrode terminal 50 may be made of aluminum or steel material, but the present invention is not limited thereto.

[0131] The terminal gasket 54 may be made of an insulating and elastic polymer resin. In one example, the terminal gasket 54 may be made of polypropylene, polybutylene terephthalate, polytetrafluoroethylene, etc., but the present invention is not limited thereto.

[0132] Desirably, the electrode terminal 50 includes a neck portion 50a inserted into the through hole 53, a head portion 50b exposed on the outer surface 52a of the bottom 52, and a protruding portion 50e exposed on the inner surface 52b of the bottom 52 of the battery housing H and extending in the axial direction.

[0133] The head portion 50b may further extend radially outward from the neck portion 50a. The diameter of the head portion 50b may be larger than the diameter of the through hole 53.

[0134] The protruding portion 50e may include a diameter-expanded portion E extending radially outward from its outer periphery and a flat portion D provided radially inward of the diameter-expanded portion E.

[0135] The diameter-expanded portion E may be formed through a forming process in which plastic deformation is performed to expand the upper end peripheral portion of the protruding portion 50e, which is smaller than the through-hole 53, radially outward. That is, the diameter-expanded portion E may be a plastic working portion 50c1.

[0136] In one example, the plastic working portion 50c1 may be formed by a riveting process using a caulking jig. After the riveting process, the diameter of the diameter-expanded portion E is expanded more than the diameter of the through-hole 53.

[0137] The tip surface 50d of the protruding portion 50e is a surface provided at the end of the protruding portion 50e and provides a flat portion D that is flat in the axial direction.

[0138] Desirably, the flat portion D and the inner surface 52b of the bottom 52 of the battery housing H may be parallel. Here, "parallel" means substantially parallel when observed visually.

[0139] According to one form, the diameter-expanded portion E may include a first section 501c that gradually moves away from the inner surface 52b toward the centrifugal side as shown in FIG. 6. The angle θ between the surface of the first section 501c of the diameter-expanded portion E facing the bottom 52 and the inner surface 52b of the bottom 52 may be 0° or more and 60° or less.

[0140] The magnitude of the angle θ is determined by the strength of the riveting process when the electrode terminal 50 is attached to the through-hole 53 of the battery housing H by the riveting method. In one example, as the riveting strength increases, the angle θ may decrease to 0°. If the angle exceeds 60°, the sealing effect of the terminal gasket 54 may decrease.

[0141] According to another form, as shown in FIG. 9, the diameter-expanded portion E includes a first section 501c that gradually moves away from the inner surface 52b toward the centrifugal side, and may have a shape that further includes a second section 502c that is connected to the centrifugal-side end of the first section 501c and gradually approaches the inner surface 52b toward the centrifugal side. The angle Φ between the surface of the second section 502c of the diameter-expanded portion E facing the bottom 52 and the inner surface 52b of the bottom 52 may be more than 0° and 30° or less.

[0142] The second section 502c may be further formed after the first section 501c is formed.

[0143] The second section 502c presses the terminal gasket 54 so that the terminal gasket 54 inclines along the bottom 52 without excessively rising from the inner surface 52b of the bottom 52. If the angle exceeds 30°, there is a risk that the boundary between the first section 501c and the second section 502c will be excessively plastically deformed.

[0144] The second section 502c provides a structure that prevents the diameter-expanded portion E from protruding further axially than the flat portion D. Thereby, the height of the axially protruding flat portion D can be reduced to the maximum, and the utilization rate of the internal space of the battery housing H can be increased.

[0145] The tip surface 50d may protrude further axially than the diameter-expanded portion E.

[0146] According to another form, a groove portion 55 may be provided between the diameter-expanded portion E and the flat portion D. The groove portion 55 may have a cross-sectional structure of an asymmetric groove. In one example, the asymmetric groove may be substantially V-shaped or U-shaped. The asymmetric groove may include a side wall surface 55a on the flat portion D side and a side wall surface 55b on the diameter-expanded portion E side facing the side wall surface 55a. The side wall surface 55a may be substantially perpendicular to the inner surface 52b of the bottom 52 of the battery housing H. "Perpendicular" means substantially perpendicular when observed visually. The groove portion 55 may be formed by the shape of a caulking jig when the electrode terminal 50 is attached to the through hole 53 of the battery housing H.

[0147] Desirably, the thickness of the diameter-expanded portion E can gradually decrease toward the outer side in the radial direction. Such a thickness reduction structure provides a compact structure that sufficiently crimps the terminal gasket 54 in the centripetal direction of the diameter-expanded portion E while ensuring that the centrifugal-direction end portion of the diameter-expanded portion E does not protrude beyond the flat portion D. As a result, the height of the axially protruding flat portion D can be minimized, thereby increasing the utilization rate of the internal space of the battery housing.

[0148] According to another form, the terminal gasket 54 may include an external gasket 54a interposed between the head portion 50b and the outer surface 52a of the bottom portion 52, and an internal gasket 54b interposed between the diameter-expanded portion E and the inner surface 52b of the bottom portion 52.

[0149] Referring to FIG. 7, the external gasket 54a and the internal gasket 54b may have different thicknesses depending on their positions. Desirably, among the regions of the internal gasket 54b, the thickness of the region interposed between the inner edge 56 of the through-hole 53 connected to the inner surface 52b of the bottom portion 52 of the battery housing H and the diameter-expanded portion E may be relatively thin. Desirably, a minimum thickness point may exist in the gasket region interposed between the inner edge 56 of the through-hole 53 and the diameter-expanded portion E. Further, the inner edge 56 of the through-hole 53 may include a facing surface 57 facing the diameter-expanded portion E. The facing surface 57 functions as a chamfer to prevent the pressure exerted by the diameter-expanded portion E on the terminal gasket 54 from being excessively concentrated on the inner edge 56 portion.

[0150] On the other hand, the upper and lower ends of the inner peripheral wall of the through-hole 53 perpendicular to the bottom portion 52 are chamfered so as to form tapered surfaces toward the electrode terminal 50. However, the upper and / or lower ends of the inner wall of the through-hole 53 may be deformed into smooth curved surfaces having a curvature. In this case, the stress applied to the terminal gasket 54 near the upper and / or lower ends of the inner wall of the through-hole 53 can be further alleviated.

[0151] The inner gasket 54b can form an angle of 0° to 60° with the inner surface 52b of the bottom 52 of the battery housing H and extend longer than the diameter-expanded portion E. Thereby, it is possible to prevent the phenomenon that the centrifugal side end of the diameter-expanded portion E comes into contact with the bottom 52 of the battery housing H.

[0152] In still another form, based on the inner surface 52b of the bottom 52 of the battery housing H, the height H1 of the flat portion D can be the same as or greater than the height H2 of the end of the inner gasket 54b. Also, based on the inner surface 52b of the bottom 52 of the battery housing H, the height H1 of the flat portion D can be the same as or greater than the height H3 of the end of the diameter-expanded portion E.

[0153] When the height parameters H1, H2, and H3 satisfy the above conditions, it is possible to prevent the diameter-expanded portion E and the inner gasket 54b from interfering with other components (for example, the second current collector described later).

[0154] Referring to FIG. 5, the radius R1 from the center of the electrode terminal 50 to the periphery of the head portion 50b can be 10% to 60% based on the radius R2 of the bottom 52.

[0155] When R1 becomes smaller, the welding space becomes insufficient when welding an electrical wiring component (bus bar) to the electrode terminal 50. Also, when R1 becomes larger, the welding space decreases when welding an electrical wiring component (bus bar) to the outer surface 52a of the bottom 52 of the battery housing H excluding the electrode terminal 50.

[0156] By adjusting the ratio R1 / R2 to 10% to 60%, it is possible to appropriately secure the welding space for the electrode terminal 50 and the outer surface of the bottom 52.

[0157] Also, the radius R3 from the center of the electrode terminal 50 to the periphery of the flat portion D can be 4% to 30% based on the radius R2 of the bottom 52.

[0158] When R3 becomes small, the welding space becomes insufficient when welding the current collector (see 79 in FIG. 8) to the flat portion D of the electrode terminal 50, the welding area of the electrode terminal 50 decreases, and the contact resistance may increase.

[0159] Also, in order to insert the electrode terminal 50 into the through hole 53, R3 must be smaller than the radius of the through hole 53. However, when R3 increases under such constraints, the diameter-expanded portion E becomes thinner accordingly, and the force with which the diameter-expanded portion E crimps the terminal gasket 54 becomes weaker, and there is a possibility that the sealing ability of the terminal gasket 54 may decrease.

[0160] When adjusting R3 / R2 to be 4% to 30%, as shown in FIG. 8, not only can the welding process be easily performed by sufficiently securing the welding area between the flat portion D of the electrode terminal 50 and the current collector 79, but also the contact resistance in the welding region can be reduced, and a decrease in the sealing ability of the terminal gasket 54 can be prevented.

[0161] According to an embodiment of the present invention, the riveting structure of the electrode terminal 50 can be formed using a caulking jig that moves up and down. First, a preform (not shown) of the electrode terminal 50 is inserted into the through hole 53 formed in the bottom portion 52 of the battery housing H with the terminal gasket 54 interposed therebetween. A preform refers to an electrode terminal before being riveted.

[0162] Next, the caulking jig is inserted into the inner space of the battery housing H. The caulking jig has grooves and protrusions corresponding to the final shape of the electrode terminal 50 on the surface facing the preform in order to rivet the preform to form the electrode terminal 50.

[0163] Next, the caulking jig is moved downward to press-mold the upper portion of the preform, and the preform is plastically deformed into the riveted electrode terminal 50.

[0164] The pushing depth of the caulking jig can be regulated by the tip surface 50d. Thereby, even in the mass production process, the shape of the diameter-expanded portion E that is plastically deformed can be uniformly controlled.

[0165] Further, the tip surface 50d is not deformed or hardly deformed during the pushing process of the caulking jig. Therefore, the tip surface 50d can also maintain a uniform shape during the mass production process. This facilitates the welding process between the tip surface 50d and the current collector (79 in FIG. 8), and thereby can significantly reduce manufacturing deviations.

[0166] While the preform is being pressurized by the caulking jig, the outer gasket 54a interposed between the head portion 50b and the outer surface 52a of the bottom portion 52 is elastically compressed and its thickness decreases. Also, the thickness of the inner gasket 54b portion interposed between the inner edge 56 of the through hole 53 and the preform decreases further than other regions while being elastically compressed by the diameter-expanded portion E. In particular, the region where the thickness of the inner gasket 54b decreases intensively is the portion indicated by the dashed-dotted circle in FIG. 7. Thereby, the sealing property and airtightness between the riveted electrode terminal 50 and the battery housing H are significantly improved.

[0167] Desirably, the terminal gasket 54 is sufficiently compressed so that the preform is not physically damaged during the riveting process and the desired sealing strength can be ensured.

[0168] In one example, when the terminal gasket 54 is made of polybutylene terephthalate, it is desirable that the compression ratio of the terminal gasket 54 at the point where it is compressed to the minimum thickness is 50% or more. The compression ratio is the ratio of the thickness change before and after compression to the thickness before compression.

[0169] As another example, when the terminal gasket 54 is made of polytetrafluoroethylene, it is desirable that the compression ratio of the terminal gasket 54 at the point where it is compressed to the minimum thickness is 60% or more.

[0170] As yet another example, when the terminal gasket 54 is made of polypropylene, it is desirable that the compression rate of the terminal gasket 54 at the point where it is compressed to the minimum thickness is 60% or more.

[0171] Desirably, by moving the caulking jig up and down at least twice, the press forming of the upper part of the preform can be carried out step by step. That is, the preform can be press formed step by step and plastically deformed in several stages. At this time, the pressure applied to the caulking jig may be increased step by step. By doing so, the stress applied to the preform is dispersed in several stages, and it is possible to prevent the terminal gasket 54 from being damaged during the caulking process. In particular, when the inner gasket 54b portion interposed between the inner edge 56 of the through hole 53 and the preform is intensively compressed by the diameter-expanded portion E, the damage to the gasket is minimized.

[0172] After the press forming of the preform using the caulking jig is completed and the caulking jig is removed from the battery housing H, as shown in FIG. 7, the fixing structure of the electrode terminal 50 according to the embodiment of the present invention is obtained.

[0173] According to the above-described embodiment, the caulking jig press forms the upper part of the preform through vertical movement inside the battery housing H. In some cases, a conventional rotary jig may be used for press forming the preform.

[0174] However, the rotary jig rotates in a state inclined by a predetermined angle with respect to the central axis of the battery housing H. Therefore, a rotary jig with a large rotation radius may interfere with the inner wall of the battery housing H. Also, when the battery housing H is deep, the length of the rotary jig also becomes longer. In this case, the rotation radius of the end of the rotary jig becomes large, and the press forming of the preform may not be sufficiently performed. Therefore, the press forming using the caulking jig is more effective than the method using the rotary jig.

[0175] The diameter-expanded portion E can be formed not only by the plastic working described above, but also by using physical fastening members 50c2 and 50c3.

[0176] Referring to FIGS. 10 and 11, the protruding portion 50e of the electrode terminal 50 can have its cross-section in the axial direction expanded by the coupling of the fastening member 50c2. The fastening member 50c2 can be a C-shaped snap ring.

[0177] A fastening groove 50g extending along the circumferential direction can be provided on the outer peripheral surface of the protruding portion 50e of the electrode terminal 50. The fastening groove 50g can be in the form of an annular groove where the cross-section of the protruding portion 50e is reduced.

[0178] As shown in FIG. 10, the fastening member 50c2 can be pushed in from the tip surface 50d side of the protruding portion 50e and fitted into the fastening groove 50g. In this process, the C-shaped snap ring is elastically deformed so that its radius is expanded, and when it is fitted into the fastening groove 50g, it is elastically restored so that its radius shrinks again, and can be firmly fastened to the fastening groove 50g.

[0179] When the fastening member 50c2 is fitted and fixed in the fastening groove 50g, the fastening member 50c2 is integrated with the protruding portion 50e. Thereby, the protruding portion 50e can have a structure in which its cross-section is further expanded in the radial direction along the axial direction. That is, after the fastening member 50c2 is fastened to the protruding portion 50e, the fastening member 50c2 can constitute the diameter-expanded portion E of the protruding portion 50e.

[0180] The surface of the fastening member 50c2 facing the bottom portion 52 has a shape that becomes farther from the bottom portion 52 toward the outer side in the radial direction. Therefore, the fastening member 50c2 has a structure inclined by a predetermined angle θ with respect to the bottom portion 52, similar to the first section 501c of the plastic working portion 50c1.

[0181] Referring to FIGS. 12 and 13, in order to enhance the sealing property of the electrode terminal 50, a first sealing coating layer f1 may be provided between the terminal gasket 54 and the bottom 52 of the battery housing H. The first sealing coating layer f1 may be formed in advance on the bottom 52 of the battery housing H and the through hole 53 before attaching the electrode terminal 50 to the through hole 53.

[0182] Optionally, in order to enhance the sealing property of the electrode terminal 50, a second sealing coating layer f2 may cover the external exposure interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the external exposure interface between the fastening member 50c2 and the terminal gasket 54. The second sealing coating layer f2 may be formed using a spray coating method after the attachment of the electrode terminal 50 is completed.

[0183] It should be understood that in the present invention, the first sealing coating layer f1 and / or the second sealing coating layer f2 are not essential elements but optional elements.

[0184] The first sealing coating layer f1 and / or the second sealing coating layer f2 may be made of a material having excellent sealing property and resistance to the electrolyte. As the material of the sealing coating layer (the first sealing coating layer f1, the second sealing coating layer f2), silicone resin, silicone acrylate or polyamideimide may be used, but the present invention is not limited thereto.

[0185] Referring to FIG. 14, the electrode terminal 50 may include an enlarged diameter portion E formed by a bolt / nut coupling structure.

[0186] Specifically, a fastening groove 50g having a male thread shape may be formed on the upper outer peripheral surface of the protruding portion 50e of the electrode terminal 50. Also, the fastening member 50c3 may be a nut having a female thread formed on its inner peripheral surface.

[0187] The surface of the fastening member 50c3 having the nut structure facing the bottom 52 of the battery housing H may include a shape that gradually moves away from the bottom 52 toward the outer side in the radial direction. Therefore, since the fastening member 50c3 has a structure inclined by a predetermined angle θ with respect to the bottom 52, similar to the first section 501c of the plastic working section 50c1, the terminal gasket 54 can be crimped to provide sealing performance.

[0188] Also in the second embodiment, the tip surface 50d of the protruding portion 50e includes a flat flat portion D. And the flat portion D may protrude further axially than the fastening member 50c3. Further, the flat portion D can maintain its dimensions and shape without being affected by the fastening of the fastening member 50c3.

[0189] Referring to FIGS. 15 and 16, in order to enhance the sealing performance of the electrode terminal 50, a first sealing coating layer f1 may be provided between the terminal gasket 54 and the bottom 52 of the battery housing H. The first sealing coating layer f1 can be formed in advance on the bottom 52 of the battery housing H and the through hole 53 before attaching the electrode terminal 50 to the through hole 53.

[0190] Optionally, in order to enhance the sealing performance of the electrode terminal 50, a second sealing coating layer f2 may cover the external exposure interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the external exposure interface between the fastening member 50c3 and the terminal gasket 54. The second sealing coating layer f2 can be formed using a spray coating method after the attachment of the electrode terminal 50 is completed.

[0191] It should be understood that in the present invention, the first sealing coating layer f1 and / or the second sealing coating layer f2 are not essential elements but optional elements.

[0192] The first sealing coating layer f1 and / or the second sealing coating layer f2 may be made of a material with excellent sealing properties and resistant to electrolytes. As the material for the sealing coating layer (the first sealing coating layer f1, the second sealing coating layer f2), silicone resin, silicone acrylate or polyamideimide may be used, but the present invention is not limited thereto.

[0193] The fixing structure of the electrode terminal 50 according to the embodiment of the present invention described above is applicable to a cylindrical battery.

[0194] Desirably, the cylindrical battery may be, for example, a cylindrical battery having a form factor ratio (defined as the value obtained by dividing the diameter of the cylindrical battery by the height of the cylindrical battery) greater than about 0.4.

[0195] Here, the form factor means a numerical sequence indicating the diameter and height of the cylindrical battery. The cylindrical battery according to an embodiment of the present invention may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the numerical value indicating the form factor, the first two digits indicate the diameter of the battery, and the remaining digits indicate the height of the battery.

[0196] A battery according to an embodiment of the present invention may be a substantially cylindrical battery having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0197] A battery according to another embodiment may be a substantially cylindrical battery having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0198] Batteries according to yet other embodiments can be cylindrical batteries that are substantially cylindrical, have a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.436.

[0199] Batteries according to yet other embodiments can be cylindrical batteries that are substantially cylindrical, have a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0200] Batteries according to yet other embodiments can be cylindrical batteries that are substantially cylindrical, have a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0201] Conventionally, batteries with a form factor ratio of about 0.4 or less have been used. That is, conventionally, for example, 1865 batteries, 2170 batteries, etc. have been used. In the case of an 1865 battery, the diameter is about 18 mm, the height is about 65 mm, and the form factor ratio is 0.277. In the case of a 2170 battery, the diameter is about 21 mm, the height is about 70 mm, and the form factor ratio is 0.300.

[0202] FIG. 8 is a cross-sectional view of a cylindrical battery 70 according to an embodiment of the present invention cut along a plane including the axial direction (Y-axis) and the radial direction (Z-axis).

[0203] Referring to FIG. 8, a cylindrical battery 70 according to an embodiment includes a jelly roll type electrode assembly 71 in which a sheet-like first electrode and a second electrode are wound with a separator interposed therebetween, a plain portion 72 of the first electrode is exposed at the bottom, and a plain portion 73 of the second electrode is exposed at the top.

[0204] In an embodiment, the first electrode can be a negative electrode and the second electrode can be a positive electrode. Of course, the opposite case is also possible.

[0205] The method of winding the electrode assembly 71 is substantially the same as the method of winding the electrode assembly used in the manufacture of the conventional tabless cylindrical battery described above with reference to FIG. 2.

[0206] In the illustration of the electrode assembly 71, only the plain portions 72 and 73 exposed and extended outside the separator are shown in detail, and the illustration of the winding structure of the first electrode, the second electrode, and the separator is omitted.

[0207] The cylindrical battery 70 includes a cylindrical battery housing H that houses the electrode assembly 71 and is electrically connected to the plain portion 72 of the first electrode.

[0208] Desirably, one side (lower part) of the battery housing H is open. Also, the bottom 52 of the battery housing H has a structure in which the electrode terminal 50 is riveted to the through hole 53 through a caulking process.

[0209] The cylindrical battery 70 may include a terminal gasket 54 interposed between the electrode terminal 50 and the through hole 53.

[0210] The cylindrical battery 70 may also include a sealing body 74 that seals the open end of the battery housing H so as to be insulated from the battery housing H. Desirably, the sealing body 74 may include a non-polar cap 74a and a sealing gasket 74b interposed between the periphery of the cap 74a and the open end of the battery housing H.

[0211] The cap 74a may be made of a conductive metal material such as aluminum, steel, or nickel. Also, the sealing gasket 74b may be made of an insulating and elastic material such as polypropylene, polybutylene terephthalate, or polytetrafluoroethylene. However, the present invention is not limited by the materials of the cap 74a and the sealing gasket 74b.

[0212] The cap 74a may include a venting notch 77 that ruptures when the internal pressure of the battery housing H exceeds a critical value. The venting notch 77 may be formed on both sides of the cap 74a. The venting notch 77 may form a continuous or discontinuous circular pattern, linear pattern, or other pattern on the surface of the cap 74a.

[0213] The battery housing H may include a crimping portion 75 that extends and is bent inside the battery housing H to fix the sealing body 74, and wraps and fixes the peripheral edge of the cap 74a together with the sealing gasket 74b.

[0214] Further, the battery housing H may include a beading portion 76 that is pushed inside the battery housing H in a region adjacent to the open end. The beading portion 76 supports the peripheral edge of the sealing body 74, particularly the outer peripheral surface of the sealing gasket 74b, when the sealing body 74 is fixed by the crimping portion 75.

[0215] Further, the cylindrical battery 70 may further include a first current collector 78 that is welded to the non-coated portion 72 of the first electrode. The first current collector 78 is made of a conductive metal material such as aluminum, steel, or nickel. Desirably, at least a part 78a of the peripheral edge of the first current collector 78 that does not contact the non-coated portion 72 of the first electrode may be interposed between the beading portion 76 and the sealing gasket 74b and fixed by the crimping portion 75. Optionally, at least a part 78a of the peripheral edge of the first current collector 78 may be fixed to the inner peripheral surface 76a of the beading portion 76 adjacent to the crimping portion 75 through welding.

[0216] Further, the cylindrical battery 70 may include a second current collector 79 that is welded to the non-coated portion 73 of the second electrode. Desirably, at least a part of the second current collector 79, for example, the central portion 79a, may be welded to the flat portion D of the electrode terminal 50.

[0217] Desirably, during the welding of the second current collector 79, the welding tool can be inserted through the cavity 80 present in the core of the electrode assembly 71 to reach the welding point of the second current collector 79. Further, when the second current collector 79 is welded to the flat portion D of the electrode terminal 50, since the electrode terminal 50 supports the welding region of the second current collector 79, a strong pressure can be applied to the welding region to improve the welding quality. Also, since the flat portion D of the electrode terminal 50 has a large area, a wide welding region can be ensured. Thereby, by reducing the contact resistance of the welding region, the internal resistance of the cylindrical battery 70 can be reduced. The face-to-face welding structure of the riveted electrode terminal 50 and the second current collector 79 is very useful for rapid charging using a high C-rate current. This is because the current density per unit area in the cross-section in the direction of current flow can be reduced, and thus the amount of heat generated in the current path can be reduced compared to the conventional case.

[0218] During the welding of the flat portion D of the electrode terminal 50 and the second current collector 79, any one of laser welding, ultrasonic welding, spot welding, and resistance welding can be used. The area of the flat portion D can be adjusted to vary depending on the welding method, but it is preferably 2 mm or more for the welding strength and the ease of the welding process.

[0219] In one example, when the flat portion D and the second current collector 79 are welded by laser and welded in an arc pattern consisting of continuous or discontinuous lines, the diameter of the flat portion D is preferably 4 mm or more. When the diameter of the flat portion D satisfies the corresponding conditions, the welding strength can be ensured, and it becomes easy to insert the laser welding tool into the cavity 80 of the electrode assembly 71 to perform the welding process.

[0220] As another example, when the flat portion D and the second current collector 79 are welded by ultrasonic and welded in a circular pattern, the diameter of the flat portion D is preferably 2 mm or more. When the diameter of the flat portion D satisfies the corresponding conditions, the welding strength can be ensured, and it becomes easy to insert the ultrasonic welding tool into the cavity 80 of the electrode assembly 71 to perform the welding process.

[0221] In addition, the cylindrical battery 70 may further include an insulator 81. The insulator 81 may be interposed between the second current collector 79 and the inner surface 52b of the bottom portion 52, and between the inner peripheral surface 51a of the side wall of the battery housing H and the electrode assembly 71. Desirably, the insulator 81 includes a welding hole 80a that exposes the flat portion D of the electrode terminal 50 to the second current collector 79 side, and may cover the surface of the second current collector 79 and one side (upper portion) end of the electrode assembly 71.

[0222] Desirably, the non-coated portion 72 of the first electrode and / or the non-coated portion 73 of the second electrode can form a bent surface on the upper and lower portions of the electrode assembly 71 by being bent from the outer peripheral side to the core side of the electrode assembly 71. Further, the first current collector 78 may be welded to the bent surface formed while the non-coated portion 72 of the first electrode is being bent, and the second current collector 79 may be welded to the bent surface formed while the non-coated portion 73 of the second electrode is being bent.

[0223] To relieve the stress generated when the non-coated portions 72 and 73 are bent, the first electrode and / or the second electrode may have an improved structure different from that of a conventional electrode (see FIG. 1).

[0224] FIG. 17 is a plan view exemplarily showing the structure of an electrode 90 according to a desirable embodiment of the present invention.

[0225] Referring to FIG. 17, the electrode 90 includes a sheet-like electrode current collector 91 made of a foil of a conductive material, an active material layer 92 formed on at least one surface of the electrode current collector 91, and a non-coated portion 93 where the active material is not coated on the long side end portion of the electrode current collector 91.

[0226] Desirably, the non-coated portion 93 may include a plurality of segmented pieces 93a that are notched. The plurality of segmented pieces 93a form a plurality of groups, and the segmented pieces 93a belonging to each group may have the same height (length in the Y direction) and / or width (length in the X direction) and / or separation pitch. The number of segmented pieces 93a belonging to each group may increase or decrease compared to that shown in the figure. The segmented pieces 93a may be trapezoidal, but may be deformed into a square, a parallelogram, a semi-circle, or a semi-ellipse.

[0227] Desirably, the height of the slit piece 93a may increase stepwise from the core side toward the outer peripheral side. Further, the core-side non-patterned portion 93' adjacent to the core side may not include the slit piece 93a, and the height of the core-side non-patterned portion 93' may be lower than that of other non-patterned portion regions.

[0228] Optionally, the electrode 90 may include an insulating coating layer 94 that covers the boundary between the active material layer 92 and the non-patterned portion 93. The insulating coating layer 94 includes an insulating polymer resin and may further selectively include an inorganic filler. The insulating coating layer 94 prevents the end of the active material layer 92 from contacting the active material layer of the opposite polarity facing through the separator, and serves to structurally support the bending of the slit piece 93a. Therefore, when the electrode 90 is wound as an electrode assembly, it is desirable that at least a part of the insulating coating layer 94 is exposed to the outside from the separator.

[0229] FIG. 18 is a cross-sectional view obtained by cutting an electrode assembly 100 in which the slit structure of the non-patterned portion of the electrode 90 according to an embodiment of the present invention is applied to a first electrode and a second electrode along a plane including the axial direction (Y-axis) and the radial direction (Z-axis).

[0230] Referring to FIG. 18, the electrode assembly 100 can be manufactured by the winding method described with reference to FIG. 2. For convenience of explanation, the protruding structures of the non-patterned portions 72 and 73 extended outside the separator are shown in detail, and the illustration of the winding structure of the first electrode, the second electrode, and the separator is omitted. The non-patterned portion 72 protruding downward is extended from the first electrode, and the non-patterned portion 73 protruding upward is extended from the second electrode.

[0231] The patterns in which the heights of the non-printing portions 72 and 73 change are schematically illustrated. That is, depending on the cutting position of the cross-section, the heights of the non-printing portions 72 and 73 can change irregularly. As an example, if the side of the trapezoidal segment 93a is cut, the height of the non-printing portion in the cross-section will be lower than the height of the segment 93a. Therefore, it must be understood that the heights of the non-printing portions 72 and 73 shown in the drawing of the cross-section of the electrode assembly 100 correspond to the average of the heights of the non-printing portions included in each winding turn.

[0232] As shown in FIG. 19, the non-printing portions 72 and 73 can be bent from the outer peripheral side to the core side of the electrode assembly 100. In FIG. 18, the bent portion 101 is shown by a dashed box. When the non-printing portions 72 and 73 are bent, bent surfaces 102 are formed at the upper and lower portions of the electrode assembly 100 while the segments adjacent in the radial direction overlap multiply. At this time, the core-side non-printing portion (93' in FIG. 17) has a low height and is not bent, and the height h of the segment bent at the innermost side is the same as or smaller than the radial length r of the winding region formed by the core-side non-printing portion 93' without the segment structure. Therefore, the cavity 80 in the core of the electrode assembly 100 is not closed by the bent segments. If the cavity 80 is not closed, there is no problem in the electrolyte injection process, and the efficiency of electrolyte injection is improved. Also, a welding tool can be inserted through the cavity 80 to easily weld the electrode terminal 50 and the second current collector 79.

[0233] In the cylindrical battery 70 according to the embodiment of the present invention, the cap 74a of the sealing body 74 has no polarity. Instead, since the first current collector 78 is connected to the side wall of the battery housing H, the outer surface 52a of the bottom 52 has the opposite polarity to the electrode terminal 50. Therefore, when connecting a plurality of batteries in series and / or in parallel, wiring such as bus bar connection can be performed on one side of the cylindrical battery 70 using the outer surface 52a of the bottom 52 and the electrode terminal 50. Thereby, the number of batteries that can be mounted in the same space can be increased to improve the energy density.

[0234] In the present invention, the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode can be used without limitation as long as they are active materials known in the art.

[0235] In one example, the positive electrode active material may include a lithium-containing compound represented by the general chemical formula A[A x M y O 2+z (A contains at least one element of Li, Na, and K; M contains 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; 0≦x, 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).

[0236] As 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 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).

[0237] As yet 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 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; M 3contains 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 can 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].

[0238] Desirably, the positive electrode active material may contain primary particles and / or secondary particles aggregated from primary particles.

[0239] In one example, as the negative electrode active material, a carbon material, a lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. can be used. Metal oxides such as TiO2 and SnO2 with a potential 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.

[0240] As the separation membrane, a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as a polyethylene homopolymer, a polypropylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., can be used alone or by laminating these. As another example, the separation membrane can use a normal porous non-woven fabric, for example, a non-woven fabric made of high-melting glass fibers, polyethylene terephthalate fibers, etc.

[0241] At least one surface of the separation membrane may contain a coating layer of inorganic particles. Also, the separation membrane itself may consist of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure bonded to a binder so that an interstitial volume exists between adjacent particles.

[0242] The inorganic particles can be composed of an inorganic substance having a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles can include at least one substance 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.

[0243] The electrolyte can be a salt having a structure such as A + B - . Here, A + includes ions consisting of alkali metal cations such as Li + , Na + , K + or combinations thereof. And B - includes 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 any one or more anions selected from the group consisting of (CF3CF2SO2)2N - and contains.

[0244] In addition, the electrolyte can be used by dissolving it in an organic solvent. As the organic solvent, 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 can be used.

[0245] The cylindrical battery according to the above-described embodiment can be used for manufacturing a battery pack.

[0246] FIG. 20 is a diagram schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0247] Referring to FIG. 20, a battery pack 200 according to an embodiment of the present invention includes an assembly in which a cylindrical battery 201 is electrically connected, and a pack housing 202 that houses the same. The cylindrical battery 201 can be the battery according to the above-described embodiment. For the sake of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrical connection of the cylindrical battery 201 are not shown.

[0248] The battery pack 200 can be mounted on an automobile. The automobile can be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a four-wheel vehicle or a two-wheel vehicle.

[0249] FIG. 21 is a view for explaining an automobile including the battery pack 200 of FIG. 20.

[0250] Referring to FIG. 21, an automobile V according to an embodiment of the present invention includes a battery pack 200 according to an embodiment of the present invention. The automobile V operates by receiving power supply from the battery pack 200 according to an embodiment of the present invention.

[0251] The above-described embodiments are illustrative in all respects and not restrictive. The scope of the present invention is represented by the appended claims rather than the above detailed description. And, of course, all changes and deformable forms derived from the equivalent concept of the meaning and scope of the claims are construed to be included in the scope of the present invention.

[0252] Although the present invention has been described with reference to the drawings exemplifying the same as above, the present invention is not limited by the embodiments shown in this specification and the drawings, and it is obvious that it can be variously deformed by those skilled in the art within the scope of the technical idea of the present invention. Furthermore, it goes without saying that even when the effects of the configuration of the present invention are not explicitly shown in the description of the embodiments, the effects predictable by the corresponding configuration must also be recognized.

[0253] Furthermore, it is also preferable that the present invention includes the following examples. [Item 1] A battery housing having an open end on one side and a bottom portion having a through hole formed on the other side, An electrode terminal fixed to the bottom, A terminal gasket interposed between the electrode terminal and the bottom, A fixing structure of the electrode terminal including: The electrode terminal, A neck portion having a cross section smaller than that of the through hole and inserted into the through hole, A head portion connected to one end of the neck portion and having a cross section larger than that of the through hole and extending along one surface of the bottom, A protruding portion that is connected to the other end portion of the neck portion and extends along the axial direction of the battery housing from the other surface of the bottom portion; A diameter-expanded portion that extends in the centrifugal direction from the protruding portion; A tip surface provided at the axial end of the protruding portion; Comprising; The diameter-expanded portion is a fastening member physically coupled to the outer peripheral surface of the protruding portion, and is a fixing structure of an electrode terminal. [Item 2] A fastening groove that is formed along the circumferential direction and recessed in the centripetal direction is provided on the outer peripheral surface of the protruding portion; The fastening member is fitted and fixed in the fastening groove, and is the fixing structure of the electrode terminal according to Item 1. [Item 3] The fastening groove has a shape of a male thread, and the fastening member is a nut formed with a female thread that is fastened to the male thread, and is the fixing structure of the electrode terminal according to Item 2. [Item 4] The fastening groove is an O-shaped groove, and the fastening member is a C-shaped ring that is fitted in the O-shaped groove, and is the fixing structure of the electrode terminal according to Item 2. [Item 5] The surface of the fastening member facing the bottom portion includes a side wall surface that gradually moves away from the bottom portion toward the outer side in the radial direction, and is the fixing structure of the electrode terminal according to Item 2. [Item 6] When the fastening member is coupled to the fastening groove, the side wall surface crimps the terminal gasket toward the bottom portion of the battery housing, and is the fixing structure of the electrode terminal according to Item 5. [Item 7] The fixing structure of the electrode terminal according to Item 1 further includes a first sealing coating layer formed at an interface between the terminal gasket and the bottom portion of the battery housing. [Item 8] The first sealing coating layer includes a silicone resin, a silicone acrylate, or a polyamideimide, and is the fixing structure of the electrode terminal according to Item 7. [Item 9] The fixing structure of the electrode terminal according to claim 1, further comprising a second sealing coating layer covering an external exposure interface between the fastening member and the terminal gasket. [Claim 10] The fixing structure of the electrode terminal according to claim 9, wherein the second sealing coating layer covers an external exposure interface between the terminal gasket and the bottom. [Claim 11] The fixing structure of the electrode terminal according to claim 9 or 10, wherein the second sealing coating layer contains a silicone resin, a silicone acrylate, or a polyamideimide. [Claim 12] The fixing structure of the electrode terminal according to claim 1, wherein the tip surface further protrudes in the axial direction of the battery housing from the enlarged diameter portion with reference to the bottom surface of the battery housing. [Claim 13] The fixing structure of the electrode terminal according to claim 1, wherein the tip surface includes a flat portion with a flat surface. [Claim 14] The fixing structure of the electrode terminal according to claim 1, wherein the fastening member includes a first section that gradually moves away from the bottom of the battery housing as it extends in the centrifugal direction from the protruding portion. [Claim 15] The fixing structure of the electrode terminal according to claim 14, wherein in the first section, the angle formed by the surface of the fastening member facing the bottom and the bottom is more than 0° and 60° or less. [Claim 16] The fixing structure of the electrode terminal according to claim 1, wherein the enlarged diameter portion has a diameter of a cross section cut in a direction perpendicular to the central axis of the battery housing that is larger than the diameter of the through hole. [Claim 17] The fixing structure of the electrode terminal according to claim 1, wherein the enlarged diameter portion has a diameter of a cross section cut in a direction perpendicular to the central axis of the battery housing that gradually increases as it moves away from the bottom of the battery housing. [Claim 18] The fixing structure of the electrode terminal according to claim 1, having a state in which a portion of the terminal gasket interposed between the head portion and the bottom of the battery housing is crimped. [Claim 19] An electrode assembly in which a first electrode and a second electrode are wound with a separation membrane interposed therebetween, and including a plain portion of the first electrode and a plain portion of the second electrode that are extended from both side ends and exposed outside the separation membrane. A battery housing having an open end on one side, housing the electrode assembly through the open end, and being electrically connected to the first electrode. An electrode terminal that is attached through the through hole so as not to contact the inner wall of the through hole formed at the bottom of the battery housing, and is electrically connected to the second electrode. The electrode terminal has a neck portion that has a cross section smaller than the cross section of the through hole and is inserted into the through hole, a head portion that is connected to one side end of the neck portion, has a cross section larger than the cross section of the through hole, and extends along one surface of the bottom, and a protruding portion that is connected to the other side end of the neck portion and extends along the axial direction of the battery housing from the other surface of the bottom. And a diameter-expanded portion extending in the centrifugal direction from the protruding portion, a tip surface provided at the axial end of the protruding portion. Comprising The diameter-expanded portion Is an electrode terminal that is a fastening member physically coupled to the outer peripheral surface of the protruding portion. A terminal gasket interposed between the electrode terminal and the through hole. A sealing body that seals the open end of the battery housing in an insulating manner from the battery housing. A battery including [Item 20] On the outer peripheral surface of the protruding portion, a fastening groove is provided that is formed along the circumferential direction and is recessed in the centripetal direction. The battery according to item 19, wherein the fastening member is fitted and fixed in the fastening groove. [Item 21] The battery according to item 20, wherein the fastening groove has a male thread shape, and the fastening member is a nut formed with a female thread that is fastened to the male thread. [Item 22] The battery according to item 20, wherein the fastening groove is an O-shaped groove, and the fastening member is a C-shaped ring fitted into the O-shaped groove. [Item 23] The surface of the fastening member facing the bottom includes a side wall surface that gradually moves away from the bottom toward the outer side in the radial direction, for the battery according to claim 20. [Claim 24] When the fastening member is coupled to the fastening groove, the side wall surface presses the terminal gasket toward the bottom of the battery housing, for the battery according to claim 23. [Claim 25] The battery according to claim 19 further includes a first sealing coating layer formed at an interface between the terminal gasket and the bottom of the battery housing. [Claim 26] The first sealing coating layer includes a silicone resin, a silicone acrylate, or a polyamideimide, for the battery according to claim 25. [Claim 27] The battery according to claim 19 further includes a second sealing coating layer covering an externally exposed interface between the fastening member and the terminal gasket. [Claim 28] The second sealing coating layer covers an externally exposed interface between the terminal gasket and the bottom, for the battery according to claim 27. [Claim 29] The second sealing coating layer includes a silicone resin, a silicone acrylate, or a polyamideimide, for the battery according to claim 27. [Claim 30] The battery housing includes a beading portion pushed inside the battery housing in a region adjacent to the open end, The sealing body includes a non-polar cap and a sealing gasket interposed between a peripheral edge of the cap and an open end of the battery housing, for the battery according to claim 19. [Claim 31] The battery housing further includes a crimping portion that extends and is bent inside the battery housing to wrap and fix a peripheral edge of the cap together with the sealing gasket, for the battery according to claim 30. [Claim 32] Further comprising a first current collector coupled to the non-patterned portion of the first electrode, The battery according to claim 31, wherein at least a part of the periphery of the first current collector that does not contact the non-patterned portion of the first electrode is interposed between the beading portion and the sealing gasket and fixed by the crimping portion. [Claim 33] The battery according to claim 32, wherein at least a part of the periphery of the first current collector is fixed to the inner peripheral surface of the beading portion adjacent to the crimping portion through welding. [Claim 34] Further comprising a second current collector coupled to the non-patterned portion of the second electrode, The battery according to claim 19, wherein at least a part of the second current collector is welded to the tip surface of the electrode terminal. [Claim 35] The battery according to claim 34, further comprising insulators interposed between the second current collector and the inner surface of the bottom of the battery housing, and between the inner peripheral surface of the side wall of the battery housing and the electrode assembly. [Claim 36] The battery according to claim 19, wherein the ratio of the form factor obtained by dividing the diameter of the battery by the height of the battery is greater than 0.4. [Claim 37] The battery according to claim 19, wherein the AC resistance measured between the electrode terminal of the battery and the outer surface of the bottom of the battery housing is 4 mΩ or less. [Claim 38] A battery pack including a plurality of batteries according to any one of claims 19 to 37. [Claim 39] An automobile including the battery pack according to claim 38.

[0254] 10 Positive electrode 11 Negative electrode 12 Separator 20 Current collector 21 Active material 22 Non-patterned portion 30 Current collector 31 Current collector 40 Cylindrical battery, tabless cylindrical battery 41 Battery housing 42 Sealing body 43 Crimping part 44 Beading part 45 Lead 46 Insulator 50 Electrode terminal 51 Side wall 52 Bottom 53 Through hole 54 Terminal gasket 55 Groove part 56 Inner edge 57 Opposite surface 70 Cylindrical battery 71 Electrode assembly 72 Plain part 73 Plain part 74 Sealing body 75 Crimping part 76 Beading part 77 Venting notch 78 First current collector 79 Second current collector 80 Cavity 81 Insulator 90 Electrode 91 Electrode current collector 92 Active material layer 93 Plain part 94 Insulating coating layer 100 Electrode assembly 101 Bent part 102 Bent surface 200 Battery pack 201 Cylindrical battery 202 Pack housing 501 First section 502 Second section

Claims

1. A battery housing having a side wall with an open end on one side and a bottom integrally connected to the other side of the side wall with a through hole formed therein, An electrode terminal fixed to the bottom, A terminal gasket interposed between the electrode terminal and the bottom, A fixing structure of the electrode terminal including: The electrode terminal includes: A neck portion having a cross-section smaller than that of the through hole and inserted into the through hole, A head portion connected to one end of the neck portion, having a cross-section larger than that of the through hole and extending along one surface of the bottom, A protruding portion connected to the other end of the neck portion and extending along the axial direction of the battery housing from the other surface of the bottom, An enlarged diameter portion extending in a centrifugal direction from the protruding portion, A tip surface provided at an axial end of the protruding portion, And is provided with, The diameter of the cross-section of the enlarged diameter portion cut in a direction perpendicular to the central axis of the battery housing is larger than the diameter of the through hole, The outer surface of the bottom has a polarity opposite to that of the electrode terminal, A fixing structure of the electrode terminal, wherein a current collector is coupled to the tip surface.

2. The fixing structure of the electrode terminal according to claim 1, wherein the enlarged diameter portion is a fastening member physically coupled to the outer peripheral surface of the protruding portion.

3. A fastening groove is provided on the outer peripheral surface of the protruding portion, formed along the circumferential direction and recessed in the centripetal direction, The fixing structure of the electrode terminal according to claim 2, wherein the fastening member is fitted and fixed in the fastening groove.

4. The fixing structure of the electrode terminal according to claim 3, wherein the fastening groove has a shape of a male thread, and the fastening member is a nut formed with a female thread that is fastened to the male thread.

5. The fixing structure of the electrode terminal according to claim 3, wherein the fastening groove is an O-shaped groove, and the fastening member is a C-shaped ring fitted into the O-shaped groove.

6. The fixing structure of the electrode terminal according to claim 3, wherein the surface of the fastening member facing the bottom includes a side wall surface that gradually becomes farther from the bottom toward the outer side in the radial direction.

7. The fixing structure of the electrode terminal according to claim 6, wherein when the fastening member is coupled to the fastening groove, the side wall surface presses the terminal gasket toward the bottom of the battery housing.

8. The fixing structure of the electrode terminal according to claim 1, further including a first sealing coating layer formed at an interface between the terminal gasket and the bottom of the battery housing.

9. The fixing structure of the electrode terminal according to claim 2, further comprising a second sealing coating layer covering an external exposure interface between the fastening member and the terminal gasket.

10. The fixing structure of the electrode terminal according to claim 9, wherein the second sealing coating layer covers an external exposure interface between the terminal gasket and the bottom portion.

11. The fixing structure of the electrode terminal according to claim 1, wherein the tip surface further protrudes in the axial direction of the battery housing from the diameter-expanded portion with reference to the bottom surface of the battery housing.

12. The fixing structure of the electrode terminal according to claim 1, wherein the tip surface includes a flat portion with a flat surface.

13. The fixing structure of the electrode terminal according to claim 2, wherein the fastening member includes a first section that gradually moves away from the bottom of the battery housing as it extends in the centrifugal direction from the protruding portion.

14. The fixing structure of the electrode terminal according to claim 1, wherein the diameter-expanded portion gradually increases in diameter in a cross-section cut perpendicular to the central axis of the battery housing as it moves away from the bottom of the battery housing.

15. The fixing structure of the electrode terminal according to claim 1, wherein a portion of the terminal gasket interposed between the head portion and the bottom of the battery housing is in a state of being crimped.

16. The fixing structure of the electrode terminal according to claim 1, wherein the diameter-expanded portion is a plastically processed portion of the protruding portion.

17. An electrode assembly in which a first electrode and a second electrode are wound with a separation film interposed therebetween, and including a plain portion of the first electrode and a plain portion of the second electrode that are extended from both side ends and exposed outside the separation film, the fixing structure of the electrode terminal according to any one of claims 1 to 16, and a sealing body that seals an open end of the battery housing in an insulating manner from the battery housing, a battery.

18. The battery housing includes a beading portion pushed into the inside of the battery housing in a region adjacent to the open end, the sealing body includes a cap and a sealing gasket interposed between a peripheral edge of the cap and the open end of the battery housing, The battery according to claim 17, wherein the battery housing includes a crimping portion that is extended and bent inside the battery housing and wraps and fixes the peripheral edge of the cap together with the sealing gasket.

19. The battery according to claim 18, wherein the cap has no polarity.

20. Further comprising a current collector coupled to the non-patterned portion of the first electrode, The battery according to claim 18, wherein at least a part of the periphery of the current collector coupled to the non-patterned portion of the first electrode that does not contact the non-patterned portion of the first electrode is fixed to the beading portion.

21. The battery according to claim 17, wherein the current collector coupled to the front end face is at least partially coupled to the non-patterned portion of the second electrode.

22. The battery according to claim 21, further comprising an insulator interposed between the current collector coupled to the front end face and the inner surface of the bottom of the battery housing.

23. A battery pack including a plurality of the batteries according to claim 17.

24. An automobile including the battery pack according to claim 23.

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