Electrode terminal fixing structure, battery including same, battery pack, and automobile

Abstract

The present invention discloses a fixing structure for an electrode terminal, and a battery, a battery pack, and a vehicle including the same. The fixing structure for an electrode terminal includes a battery housing having an open end on one side and a bottom with a through hole formed on 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 the cross section 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 the cross section of the through hole and extending along one surface of the bottom, a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom along the axial direction of the battery housing, an enlarged diameter portion extending in a centrifugal direction from the protrusion, and a tip surface provided at an axial end of the protrusion, the enlarged diameter portion being a fastening member physically coupled to an outer circumferential surface of the protrusion.

Description

[Technical field]

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

[0002] This application claims priority to 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 the contents disclosed in the specification and drawings of said applications are incorporated herein in their entirety. [Background technology]

[0003] Secondary batteries, which have high applicability to each product group and electrical properties such as high energy density, are universally used not only in portable devices but also in electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid vehicles (PHEVs), etc., which are driven by electrical sources. Hereinafter, electric vehicles will be used as a concept that includes EVs, HEVs, PHEVs, etc.

[0004] Such secondary batteries not only have the primary advantage of dramatically reducing the use of fossil fuels, but are also environmentally friendly as they do not produce any by-products from energy use, and are attracting attention as a new energy source for improving energy efficiency.

[0005] Currently, secondary batteries such as lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, and nickel zinc batteries are widely used. The operating voltage of such secondary batteries is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack is constructed by connecting multiple batteries in series. In addition, a battery pack may be constructed by connecting multiple batteries in parallel according to the charge / discharge capacity required for the battery pack. Therefore, the number of batteries included in the battery pack and the electrical connection form may be variously set according to the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, known types of secondary batteries include cylindrical, prismatic and pouch-type batteries. In the case of cylindrical batteries, a separator, which is an insulator, is interposed between the positive and negative electrodes, and the separator is rolled up to form a jelly-roll-type electrode assembly, which is then inserted into a battery housing together with an electrolyte to form a battery. Strip-shaped electrode tabs are connected to the uncoated portions of the positive and negative electrodes, and the electrode tabs electrically connect the electrode assembly to electrode terminals exposed to the outside. For reference, the positive terminal is a sealed cap that seals the opening of the battery housing, and the negative terminal is the battery housing.

[0007] However, conventional cylindrical batteries having such a structure have problems such as high resistance, high heat generation, and poor current collection efficiency because current is concentrated at the strip-shaped electrode tabs connected to the positive electrode uncoated portion and / or the negative electrode uncoated portion.

[0008] Resistance and heat generation are not a big issue for small cylindrical batteries with form factors such as 1865 and 2170. However, when the form factor of a cylindrical battery is increased to be used in an electric vehicle, a large amount of heat is generated around the electrode tabs during the fast charging process, which can cause the cylindrical battery to catch fire.

[0009] To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) has been proposed in which positive and negative uncoated areas are designed to be located at the top and bottom of a jelly-roll type electrode assembly, respectively, and current collectors are welded to these uncoated areas to improve current collection efficiency.

[0010] Figures 1 to 3 are diagrams showing the manufacturing process of a tabless cylindrical battery. Figure 1 shows the structure of the electrode, Figure 2 shows the electrode winding process, and Figure 3 shows the process of welding a current collector to the folded surface of the uncoated part. Figure 4 is a cross-sectional view of the tabless cylindrical battery cut in the longitudinal direction (Y axis).

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

[0012] The electrode assembly A is fabricated by sequentially stacking a positive electrode 10 and a negative electrode 11 together with two separators 12 as shown in Fig. 2, and then winding the stack in one direction (X-axis direction). At this time, the uncoated portion of the positive electrode 10 and the uncoated portion of the negative electrode 11 are arranged in opposite directions.

[0013] After the winding process, the uncoated portion 10a of the positive electrode 10 and the uncoated portion 11a of the negative electrode 11 are folded toward the core side. Then, the current collectors 30 and 31 are welded and joined to the uncoated portions 10a and 11a, respectively.

[0014] No separate electrode tabs are attached to the positive electrode uncoated region 10a and the negative electrode uncoated region 11a, and the current collectors 30 and 31 are connected to external electrode terminals, so that a current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly A (see the arrow in FIG. 3), which has the advantage of reducing the resistance of the battery. This is because resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0015] However, as the form factor of cylindrical batteries increases and the charging current during fast charging becomes larger, the heat generation problem reoccurs in table-less cylindrical batteries.

[0016] Specifically, a conventional tabless cylindrical battery 40 includes a battery housing 41 and a sealing body 42, as shown in Fig. 4. 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. Also, the electrode assembly A is fixed in the battery housing 41 by a beading portion 44 to prevent vertical movement.

[0017] Typically, the positive electrode terminal is the cap 42a of the sealing body 42, and the negative electrode terminal is the battery housing 41. Thus, the current collector 30 coupled to the uncoated portion 10a of the positive electrode 10 is electrically connected to a connecting plate 42c attached to the cap 42a through a strip-shaped lead 45. Also, the current collector 31 coupled to the uncoated 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 contact between the battery housing 41 and the uncoated portion 10a of the positive electrode 10, which have opposite polarities, 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 either separately attached to the current collector 30 or is manufactured integrally with the current collector 30. However, since the lead 45 is in the form of a thin strip, its cross-sectional area is small and a large amount of heat is generated when a fast charging current flows. In addition, the excessive heat generated in the lead 45 is transferred to the electrode assembly A side and causes the separator 12 to shrink, which may cause an internal short circuit, which is a main cause of thermal runaway.

[0020] That is, in the conventional cylindrical battery structure, the current collector 31 facing the bottom of the battery housing 41 is in direct contact with the bottom of the battery housing 41, so a sufficiently large cross-sectional area is secured in the direction of current movement, 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 a strip-shaped lead 45, which inevitably causes the above-mentioned overheating problem.

[0021] In addition, in terms of manufacturing process, the leads 45 occupy a considerable amount of installation space within the battery housing 41. Therefore, the cylindrical battery 40 including the leads 45 has low space efficiency and is limited in increasing the energy density.

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

[0023] In addition, the crimping portion 43 provided on the peripheral side of the sealing body 42 is a portion having a negative polarity and is exposed to the upper part of the cylindrical battery 40. Although the upper part of the crimping portion 43 is shown large in FIG. 4, in reality, the area of ​​the crimping portion 43 exposed to the upper part is much smaller than the area of ​​the sealing body 42. Therefore, in order to stably connect the busbar parts, the sealing body 42 crimped to the opening of the battery housing 41 and the bottom part of the battery housing 41 are used. Summary of the Invention [Problem to be solved by the invention]

[0024] The present invention has been made to solve the above-mentioned problems, and aims to reduce the internal resistance of a cylindrical battery and increase its 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 structure of the electrode terminals of a cylindrical battery to increase the cross-sectional area of ​​the current path, thereby alleviating the problem of internal heat generation that occurs during fast charging.

[0026] Another object of the present invention is to provide a cylindrical battery having an improved structure in which electrical wiring for series and / or parallel connection of cylindrical batteries can be performed on one side of the cylindrical battery.

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

[0028] The technical problem of the present invention is not limited to the above-mentioned object, and other objects and advantages of the present invention not mentioned can be understood from the following description and will be more clearly understood by the embodiment of the present invention. In addition, 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 problem]

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

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

[0031] A fastening groove may be formed on an outer circumferential surface of the protrusion, the fastening member being fitted into the fastening groove and being recessed in a centripetal direction.

[0032] The fastening groove may have a shape of a male thread, and the fastening member may be a nut having a female thread formed thereon to be fastened to the male thread.

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

[0034] The surface of the fastener facing the base may include a sidewall surface that gradually extends radially outwardly away from the base.

[0035] When the fastening member is engaged with the fastening groove, the side wall surface may press the terminal gasket toward a bottom of the battery housing.

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

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

[0038] The electrode terminal fixing structure may further include a second sealing coating layer covering an externally exposed interface between the fastening member and the terminal gasket.

[0039] Optionally, the second sealing coating layer may cover the externally exposed interface between the terminal gasket and the bottom portion.

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

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

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

[0043] The fastening member may have a first section that extends centrifugal from the protrusion and gradually becomes farther from a bottom of the battery housing.

[0044] In the first section, an angle formed by a surface of the fastening member facing the bottom portion and the bottom portion may be greater than 0° and less than or equal to 60°.

[0045] The enlarged diameter portion may have a cross-sectional diameter taken in a direction perpendicular to a central axis of the battery housing that is larger than the diameter of the through hole.

[0046] The enlarged diameter portion may have a cross-sectional diameter taken along a direction perpendicular to a central axis of the battery housing that gradually increases in diameter as the cross-sectional diameter increases 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 crimped state.

[0048] In order to achieve the above object, a battery according to another aspect of the present invention includes a fixing structure for an electrode terminal including at least one of the above-mentioned features.

[0049] The battery includes an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, the electrode assembly including an uncoated portion of the first electrode and an uncoated portion of the second electrode extending from both side ends and exposed to the outside of the separator; a battery housing having an open end on one side, receiving the electrode assembly through the open end and electrically connected to the first electrode; an electrode terminal that is attached through a through hole formed in a bottom of the battery housing and electrically connected to the second electrode, the electrode terminal having a cross section smaller than the cross section of the through hole and inserted into the through hole so as not to come into contact with an inner wall of the through hole; a head portion connected to one side end of the neck portion and having a cross section larger than the cross section of the through hole and extending along one surface of the bottom portion, a protrusion connected to the other side end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing, an enlarged diameter portion extending in a centrifugal direction from the protrusion, and a tip surface provided at an axial end of the protrusion, wherein the enlarged diameter portion includes: an electrode terminal which is a fastening member physically coupled to an outer peripheral surface of the protrusion; a terminal gasket interposed between the electrode terminal and the through hole; and a sealing body which seals the open end of the battery housing so as to be insulated from the battery housing.

[0050] The battery housing may include a beading portion pressed into the inside of the battery housing in an area adjacent to the open end, and the sealing body may include a non-polarized cap and a sealing gasket interposed between a periphery of the cap and the open end of the battery housing.

[0051] The battery housing may further include a crimping portion that is extended toward the inside of the battery housing and bent to enclose and fix a periphery of the cap together with the sealing gasket.

[0052] The battery may further include a first current collector coupled to the uncoated portion of the first electrode, and at least a portion of a periphery of the first current collector that is not in contact with the uncoated portion of the first electrode may be interposed between the beading portion and the sealing gasket and fixed by the crimping portion.

[0053] At least a portion of a periphery of the first current collector may be fixed to an inner circumferential surface of the beading portion adjacent to the crimping portion by welding.

[0054] The battery may further include a second current collector coupled to the uncoated portion of the second electrode, and at least a portion of the second current collector may be welded to a tip surface of the electrode terminal.

[0055] The battery may further include an insulator interposed between the second current collector and an inner surface of a bottom of the battery housing, and between an inner peripheral surface of a sidewall of the battery housing and the electrode assembly.

[0056] The battery may be cylindrical and have a form factor ratio of the diameter of the battery divided by the height of the battery greater than 0.4.

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

[0058] The above object can also be achieved by a battery pack including a plurality of the above-described batteries, and by a vehicle including the battery pack. Effect of the Invention

[0059] According to one aspect of the present invention, the structure of the electrode terminal of a cylindrical battery is improved so that the lead can be omitted, thereby increasing the space efficiency within the battery housing, thereby reducing the internal resistance of the cylindrical battery and increasing the energy density.

[0060] In addition, according to one aspect of the present invention, the structure of the electrode terminal of a cylindrical battery is improved so that the electrode terminal and the current collector can be directly connected to each other, thereby increasing the cross-sectional area of ​​the current path, thereby improving the problem of internal heat generation that occurs during fast charging.

[0061] In addition, according to one embodiment of the present invention, by arranging both electrodes on the bottom, which is one side of the cylindrical battery, electrical wiring work for series and / or parallel connection of the cylindrical battery can be performed on one side of the cylindrical battery.

[0062] According to another aspect of the present invention, a battery pack manufactured using a cylindrical battery having an improved structure, and a vehicle including the battery pack can be provided.

[0063] The above-mentioned effects as well as specific effects of the present invention will be described later by listing specific matters for carrying out the invention. [Brief description of the drawings]

[0064] [Figure 1] FIG. 1 is a plan view showing the structure of an electrode used in a conventional tabless cylindrical battery. [Diagram 2] 1A to 1C are diagrams illustrating a winding process of an electrode assembly included in a conventional tabless cylindrical battery. [Diagram 3] 3 is a view showing a process of welding a current collector to a folded surface of an uncoated portion in the electrode assembly of FIG. 2. [Figure 4] FIG. 1 is a cross-sectional view of a conventional tabless cylindrical battery cut in the longitudinal direction (Y axis). [Diagram 5] 1 is a cross-sectional view showing a fixing structure for an electrode terminal according to a first embodiment of the present invention. [Figure 6] FIG. 6 is an enlarged view of only the electrode terminal portion in FIG. 5. [Figure 7] 6 is an enlarged cross-sectional view of a portion circled by a dashed dotted line in FIG. 5. [Figure 8] 1 is a cross-sectional view of a cylindrical battery according to an embodiment of the present invention taken along a YZ plane. [Figure 9] 5 is an enlarged view showing a modified example of the electrode terminal of the first embodiment. FIG. [Figure 10] FIG. 11 is an enlarged view of an electrode terminal according to a second embodiment. [Figure 11] FIG. 11 is an enlarged view of an electrode terminal according to a second embodiment. [Figure 12] 11 is a cross-sectional view showing a case where a sealing coating layer is applied to a fixing structure for an electrode terminal including an electrode terminal according to a second embodiment. FIG. [Figure 13] 11 is a cross-sectional view showing a case where a sealing coating layer is applied to a fixing structure for an electrode terminal including an electrode terminal according to a second embodiment. FIG. [Figure 14] 13 is an enlarged view showing a modified example of the electrode terminal of the second embodiment. FIG. [Figure 15] 13 is a cross-sectional view showing a case where a sealing coating layer is applied to a fixing structure for an electrode terminal including an electrode terminal according to a modified example of the second embodiment. FIG. [Figure 16] 13 is a cross-sectional view showing a case where a sealing coating layer is applied to a fixing structure for an electrode terminal including an electrode terminal according to a modified example of the second embodiment. FIG. [Figure 17] 1 is a plan view illustrating an example of an electrode structure according to a preferred embodiment of the present invention; [Figure 18] 1 is a cross-sectional view taken along a longitudinal direction (Y-axis) of an electrode assembly in which a division structure of an uncoated portion of an electrode according to an embodiment of the present invention is applied to a first electrode and a second electrode. [Figure 19] 4 is a cross-sectional view of an electrode assembly in which a non-coating portion is folded according to an embodiment of the present invention, taken along a longitudinal direction (Y-axis). [Figure 20] 1 is a diagram showing a schematic configuration of a battery pack including a cylindrical battery according to an embodiment of the present invention; [Figure 21] 1 is a diagram showing a schematic configuration of a vehicle including a battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0065] The objects, features and advantages of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art to which the present invention pertains can easily implement the technical ideas of the present invention. In the description of the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals refer to the same or similar components.

[0066] Although the terms "first" and "second" are used to indicate various components, 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 can also be the second component.

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

[0068] Hereinafter, when an arbitrary structure is disposed on the "top (or bottom)" of a component or "above (or below)" a component, it means not only that the arbitrary structure is disposed in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and the arbitrary structure disposed above (or below) the component.

[0069] In addition, when a component is said to be "coupled," "coupled," or "connected" to another component, this does not only mean that the components are directly coupled or connected to each other, but also that other components are "interposed" between each component, or that each component is "coupled," "coupled," or "connected" through other components.

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

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

[0072] For ease of explanation, in this specification, the direction along the length of the winding shaft of the electrode assembly wound into a jelly roll is referred to as the axial direction (Y-axis). The direction surrounding the winding shaft is referred to as the circumferential direction or outer circumferential direction (X-axis direction). The direction approaching the winding shaft or away from the winding shaft is referred to as the radial direction or radial direction (Z-axis direction). Of these, the direction particularly approaching the winding shaft is referred to as the centripetal direction, and the direction away from the winding shaft is referred to as the centrifugal direction.

[0073] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred 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. Thus, 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 one open side of the battery housing H until the tip of the electrode assembly 71 (the end of the electrode assembly that is inserted first) reaches the bottom 52 of the battery housing H.

[0077] The battery housing H has a bottom 52 formed with a through hole 53 .

[0078] The bottom 52 includes opposing first and second surfaces 52a and 52b, and the through hole 53 is a hole formed through the bottom 52 so as to connect a first space facing the first surface 52a with a second space facing the second surface 52b.

[0079] The first surface 52a may be a surface exposed to the outside of the battery housing H, whereby the first space may be the outside space of the battery housing H. The second surface 52b may be a surface facing the inside of the battery housing H, whereby the second space may be the inside 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. In this case, the second space becomes the outside space of the battery housing H, and the first space becomes the inside space of the battery housing H.

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

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

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

[0084] For example, the electrode terminal 50 may be fixed by a plastic processing portion 50c1 formed by plastic processing, which may include riveting, caulking, and the like.

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

[0086] 6, the electrode terminal 50 may include a neck portion 50a having a cross section smaller than the cross section 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 the cross section of the through hole 53. A protrusion 50e having a cross section smaller than the cross section of the through hole 53 is provided at the other end of the neck portion 50a.

[0087] After inserting the protrusion 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 protrusion 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 Figure 14) can be physically fixed to the protrusion 50e.

[0088] The plastically processed portion 50c1 or the fastening members 50c2, 50c3 constitute an enlarged diameter portion E that enlarges the cross-sectional area of ​​the protrusion 50e. As a result, the cross-section of the protrusion 50e becomes larger than the cross-section of the through hole 53, and the electrode terminal 50 is fitted into the through hole 53 and maintained in a fixed state.

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

[0090] Alternatively, the electrode terminal 50 may be inserted through a through hole 53 provided in the bottom 52 from inside the battery housing H, and the protrusion 50e may be plastically processed or fastening members 50c2, 50c3 may be fixed to the protrusion 50e outside the battery housing H. As a result, the head 50b of the electrode terminal 50 may be disposed inside the battery housing H, and the protrusion 50e of the electrode terminal 50 may be exposed to the outside of 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 have a flat region. The flat region can provide a connection surface for a bus bar or the like.

[0092] In one example, the cross section of the protrusion 50e of the electrode terminal 50 can 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 through riveting, and a tip surface 50d provided at the tip of the protruding portion 50e.

[0094] The plastically processed portion 50c1 can constitute an enlarged diameter portion E.

[0095] The tip surface 50d can be disposed on the centripetal side (radially inward) of the plastically processed portion 50c1.

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

[0097] The tip surface 50d may form a flat portion D that is generally flat.

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

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

[0100] The plastically processed portion 50c1 may include a first section 501c that gradually becomes farther from the bottom portion 52 of the battery housing H as it extends in the centrifugal direction from the protrusion 50e.

[0101] In the first section 501c, the angle between the surface of the plastic processing portion 50c1 facing the bottom portion 52 and the bottom portion 52 may be greater than 0° and less than or equal to 60°.

[0102] In one embodiment, the plastic processing portion 50c1 may be composed of only the first section 501c as shown in Fig. 6. In another embodiment, the plastic processing portion 50c1 may further include a second section 502c disposed on the centrifugal side of the first section 501c and connected to the first section 501c as shown in Fig. 9. 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 between the surface of the plastic processing portion 50c1 facing the bottom portion 52 and the bottom portion 52 may be greater than 0° and less than or equal to 30°.

[0104] Between the plastic processing portion 50c1 and the tip surface 50d, a groove portion 55 recessed in the axial direction may be provided. The groove portion 55 may be in the form of a closed loop surrounding the tip surface 50d in the circumferential direction.

[0105] Preferably, the groove portion 55 may have an asymmetric cross-sectional structure. That is, the side wall surface 55a of the flat portion D and the side wall surface 55b of the plastic processing portion 50c1 do not have to be parallel to each other.

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

[0107] A side wall surface 55a connecting the bottom of the groove portion 55 and the flat portion D may be perpendicular to a plane including the flat portion D. This allows the area of ​​the flat region of the flat portion D to be maximized.

[0108] A side wall surface 55b of the plastic processing portion 50c1 opposed to the side wall surface 55a of the flat portion D may form an inclined surface.

[0109] Desirably, the thickness of the enlarged portion E may decrease with increasing distance from the protruding portion 50e.

[0110] In another embodiment, the protrusion 50e of the electrode terminal 50 may be expanded in cross section by physical coupling of the fastening members 50c2, 50c3.

[0111] 10, a fastening groove 50g extending in a circumferential direction may be provided on an outer circumferential surface of the protrusion 50e of the electrode terminal 50. The fastening groove 50g may have a groove shape in which a cross section of the protrusion 50e is reduced. That is, the fastening groove 50g may be recessed in a centripetal direction from the outer circumferential surface of the protrusion 50e.

[0112] 11, the fastening member 50c2 is fitted and fixed in the fastening groove 50g, so that the protrusion 50e is integrated with the fastening member 50c2, thereby expanding the cross section at the upper region of the protrusion 50e. That is, the fastening member 50c2 may constitute the expanded portion E of the protrusion 50e after being fastened to the protrusion 50e. In one example, the fastening groove 50g may be 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 male thread shape, and the fastening member 50c3 may be a nut with a female thread formed thereon.

[0114] The surfaces of the fastening members 50c2, 50c3 facing the bottom 52 of the battery housing H may include a shape that gradually becomes farther away from the bottom 52 in a radially outward direction.

[0115] 11 and 14, the tip surface 50d of the protrusion 50e has a flat portion D, and the flat portion D can maintain its size 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 portion 52, between the neck portion 50a of the electrode terminal 50 and the inner circumferential surface of the through hole 53, and between the enlarged diameter portion E of the protrusion portion 50e of the electrode terminal 50 and the bottom portion 52. In this way, the terminal gasket 54 can insulate the electrode terminal 50 from the bottom portion 52 and provide air tightness for the battery housing H.

[0118] The plastically processed portion 50c1 or the side wall surfaces (surfaces facing the bottom portion 52) of the fastening members 50c2, 50c3 press the terminal gasket 54 while further pulling the head portion 50b toward the first surface 52a of the bottom portion 52. As a result, the portion of the terminal gasket 54 interposed between the head portion 50b and the first surface 52a of the bottom portion 52 is strongly pressed.

[0119] In addition, the side wall surface (the surface facing the bottom 52) of the plastically processed portion 50c1 or the fastening members 50c2, 50c3 strongly presses the terminal gasket 54 at the corner portion where the inner surface of the through hole 53 and the second surface 52b of the bottom 52 are connected.

[0120] 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 to improve the sealing performance of the terminal gasket 54.

[0121] 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 covering the externally exposed interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the externally exposed interface between the fastening members 50c2, 50c3 and the terminal gasket 54. The second sealing coating layer f2 may improve the sealing performance of the terminal gasket 54, similar to the first sealing coating layer f1.

[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 optional elements, not essential 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. The sealing coating layer (first sealing coating layer f1, second sealing coating layer f2) may be made of a material such as silicone resin, silicone acrylate, or polyamideimide, but the present invention is not limited thereto.

[0124] Hereinafter, the 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 electrode terminals riveted to the bottom of the battery housing.

[0126] FIG. 5 is a cross-sectional view showing a riveting structure of an electrode terminal 50 according to an 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 dotted line circle.

[0127] 5 to 7, the riveting structure of the electrode terminal 50 according to this embodiment may include a cylindrical battery housing H having one open side, an electrode terminal 50 riveted through a through hole 53 formed in a 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 a 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 formed integrally with the side wall 51. For example, the battery housing H may be formed integrally with the side wall 51 and the bottom 52 by drawing a metal sheet with a press.

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

[0130] The electrode terminal 50 is made of a conductive metal material. In one example, the electrode terminal 50 may be made of an 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, polyfluoroethylene, 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 portion 52, and a protrusion 50e exposed on the inner surface 52b of the bottom portion 52 of the battery housing H and extending in the axial direction.

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

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

[0135] The enlarged diameter portion E may be formed through a molding process in which plastic deformation is performed to enlarge radially outward an upper peripheral portion of the protrusion 50e that is smaller than the through hole 53. That is, the enlarged diameter portion E may be a plastically processed portion 50c1.

[0136] In one example, the plastically processed portion 50c1 may be formed by a riveting process using a caulking jig. After riveting, the diameter of the enlarged portion E is enlarged to be larger than the diameter of the through hole 53.

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

[0138] Desirably, the flat portion D and the inner surface 52b of the bottom portion 52 of the battery housing H may be parallel to each other. Here, "parallel" means that they are substantially parallel when observed with the naked eye.

[0139] According to one embodiment, the enlarged diameter portion E may include a first section 501c that is gradually farther from the inner surface 52b toward the distal side as shown in Fig. 6. An angle θ between a surface of the first section 501c of the enlarged diameter portion E facing the bottom portion 52 and the inner surface 52b of the bottom portion 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 a riveting method. In one example, as the strength of the riveting process increases, the angle θ can be reduced to 0°. If the angle exceeds 60°, the sealing effect of the terminal gasket 54 may be reduced.

[0141] 9, the expanded diameter portion E may include a first section 501c that is gradually farther from the inner surface 52b toward the distal side, and may further include a second section 502c that is connected to a distal end of the first section 501c and gradually approaches the inner surface 52b toward the distal side. An angle Φ between a surface of the second section 502c of the expanded diameter portion E facing the bottom portion 52 and the inner surface 52b of the bottom portion 52 may be greater than 0° and less than or equal to 30°.

[0142] The second section 502c may be further shaped after the shaping of the first section 501c.

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

[0144] The second section 502c provides a structure in which the expanded diameter portion E does not protrude further in the axial direction than the flat portion D. This minimizes the height of the flat portion D protruding in the axial direction, thereby improving the utilization of the internal space of the battery housing H.

[0145] The tip surface 50d may protrude further than the enlarged diameter portion E in the axial direction.

[0146] According to another embodiment, a groove 55 may be provided between the enlarged portion E and the flat portion D. The groove 55 may have an asymmetric cross-sectional structure. 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 enlarged 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 portion 52 of the battery housing H. "Perpendicular" means that the side wall surface 55 is substantially perpendicular when observed with the naked eye. The groove 55 may be formed by the shape of a crimping jig when the electrode terminal 50 is attached to the through hole 53 of the battery housing H.

[0147] Desirably, the thickness of the enlarged portion E may be gradually reduced radially outward. Such a thickness reducing structure provides a compact structure that sufficiently crimps the terminal gasket 54 in the centripetal direction of the enlarged portion E, while preventing the centrifugal end of the enlarged portion E from protruding beyond the flat portion D. This allows the height of the flat portion D protruding in the axial direction to be minimized, thereby improving the utilization of the internal space of the battery housing.

[0148] According to another embodiment, the terminal gasket 54 may include an outer gasket 54a interposed between the head portion 50b and the outer surface 52a of the base portion 52, and an inner gasket 54b interposed between the enlarged diameter portion E and the inner surface 52b of the base portion 52.

[0149] 7, the thickness of the external gasket 54a and the internal gasket 54b may vary depending on the position. Preferably, the thickness of the internal gasket 54b may be relatively thin in a region between the inner edge 56 of the through hole 53 connected to the inner surface 52b of the bottom 52 of the battery housing H and the enlarged portion E. Preferably, a minimum thickness point may be present in the gasket region between the inner edge 56 of the through hole 53 and the enlarged portion E. In addition, the inner edge 56 of the through hole 53 may include an opposing surface 57 opposing the enlarged portion E. The opposing surface 57 functions as a chamber to prevent the pressure of the enlarged portion E pressing the terminal gasket 54 from being excessively concentrated on the inner edge 56.

[0150] Meanwhile, the upper and lower ends of the inner peripheral wall of the through hole 53 perpendicular to the bottom 52 are chamfered (corner cut) to form a tapered surface 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 a smooth curved surface 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 internal gasket 54b may 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 expanded diameter portion E. This can prevent the centrifugal end of the expanded diameter portion E from coming into contact with the bottom 52 of the battery housing H.

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

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

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

[0155] If R1 becomes small, there is insufficient welding space when welding an electrical wiring component (bus bar) to the electrode terminal 50. If R1 becomes large, there is a decrease in the welding space 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 be in the range of 10% to 60%, a suitable welding space for the outer surfaces of the electrode terminal 50 and the bottom portion 52 can be secured.

[0157] Furthermore, a radius R3 from the center of the electrode terminal 50 to the periphery of the flat portion D may be 4% to 30% of the radius R2 of the bottom portion 52 as a reference.

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

[0159] Furthermore, 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, if R3 becomes larger under such constraints, the expanded diameter portion E will become thinner accordingly, and the force with which the expanded diameter portion E crimps the terminal gasket 54 will be weakened, which may reduce the sealing ability of the terminal gasket 54.

[0160] By adjusting R3 / R2 to 4% to 30%, as shown in FIG. 8, the welding area between the flat portion D of the electrode terminal 50 and the current collector 79 is sufficiently secured, which not only facilitates the welding process but also reduces the contact resistance of the welding area and prevents a decrease in the sealing ability of the terminal gasket 54.

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

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

[0163] Next, the crimping jig is moved downward to press-form the upper part of the preform, thereby plastically deforming the preform into a riveted electrode terminal 50.

[0164] The pressing depth of the crimping jig can be regulated by the tip end surface 50d, which makes it possible to uniformly control the shape of the enlarged diameter portion E that is plastically deformed even during mass production.

[0165] In addition, the front end surface 50d is not deformed or is hardly deformed during the pressing process of the crimping jig. Therefore, the front end surface 50d can maintain a uniform shape during mass production. This makes it easier to weld the front end surface 50d and the current collector (79 in FIG. 8), thereby significantly reducing manufacturing deviations.

[0166] While the preform is pressurized by the crimping tool, 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 is reduced. Also, the portion of the inner gasket 54b interposed between the inner edge 56 of the through hole 53 and the preform is elastically compressed by the enlarged diameter portion E and its thickness is reduced more than other regions. In particular, the region where the thickness of the inner gasket 54b is reduced intensively is the portion indicated by the dashed dotted circle in Figure 7. This significantly improves the sealing and hermeticity between the riveted electrode terminal 50 and the battery housing H.

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

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

[0169] As another example, if terminal gasket 54 is made of polyfluoroethylene, it is desirable for terminal gasket 54 to have a compressibility of 60% or greater at the point where it is compressed to its minimum thickness.

[0170] As yet another example, if terminal gasket 54 is made of polypropylene, it is desirable for terminal gasket 54 to have a compressibility of 60% or greater at the point where it is compressed to its minimum thickness.

[0171] Preferably, the upper part of the preform may be press-molded in stages by moving the crimping jig up and down at least twice. That is, the preform may be press-molded in stages and plastically deformed in several steps. At this time, the pressure applied to the crimping jig may be increased in stages. In this way, the stress applied to the preform may be dispersed in several steps, thereby preventing the terminal gasket 54 from being damaged during the crimping process. In particular, when the portion of the internal gasket 54b interposed between the inner edge 56 of the through hole 53 and the preform is compressed in a concentrated manner by the enlarged diameter portion E, damage to the gasket is minimized.

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

[0173] According to the above-described embodiment, the crimping jig presses the upper part of the preform by moving up and down inside the battery housing H. In some cases, a conventional rotary jig may be used for press molding the preform.

[0174] However, the rotary rotation jig rotates at a predetermined angle with respect to the central axis of the battery housing H. Therefore, a rotary rotation jig with a large rotation radius may interfere with the inner wall of the battery housing H. Furthermore, if the battery housing H is deep, the length of the rotary rotation jig will also be long. In this case, the rotation radius of the end of the rotary rotation jig becomes large, and press molding of the preform may not be performed sufficiently. Therefore, press molding using a crimping jig is more effective than the method using a rotary rotation jig.

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

[0176] 10 and 11, the protrusion 50e of the electrode terminal 50 may have an axial cross section expanded by the engagement of a fastening member 50c2. The fastening member 50c2 may be a C-shaped snap ring.

[0177] A fastening groove 50g extending in a circumferential direction may be provided on an outer circumferential surface of the protrusion 50e of the electrode terminal 50. The fastening groove 50g may be in the form of an annular groove having a reduced cross section of the protrusion 50e.

[0178] 10, the fastening member 50c2 may be inserted into the fastening groove 50g by being pressed into the tip surface 50d of the protrusion 50e. During this process, the C-shaped snap ring is elastically deformed to expand its radius, and when inserted into the fastening groove 50g, it is elastically restored to contract its radius, so that it can be firmly fastened to the fastening groove 50g.

[0179] The fastening member 50c2 is fitted and fixed in the fastening groove 50g, so that the fastening member 50c2 is integrated with the protrusion 50e. As a result, the protrusion 50e may have a structure in which the cross section is further expanded in the radial direction along the axial direction. That is, after the fastening member 50c2 is fastened to the protrusion 50e, it may constitute the expanded diameter portion E of the protrusion 50e.

[0180] The surface of the fastening member 50c2 facing the bottom 52 has a shape that becomes farther away from the bottom 52 in the radially outward direction. Therefore, the fastening member 50c2 has a structure that is inclined at a predetermined angle θ with respect to the bottom 52, similar to the first section 501c of the plastic processing portion 50c1.

[0181] 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 preliminarily formed on the bottom 52 and the through-hole 53 of the battery housing H before the electrode terminal 50 is attached 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 externally exposed interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the externally exposed interface between the fastening member 50c2 and the terminal gasket 54. The second sealing coating layer f2 may be formed by using a spray coating method after the installation 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 optional elements, not essential 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 properties and resistance to electrolytes. The sealing coating layer (first sealing coating layer f1, second sealing coating layer f2) may be made of a material such as silicone resin, silicone acrylate, or polyamideimide, but the present invention is not limited thereto.

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

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

[0187] The surface of the fastening member 50c3 having the nut structure, which faces the bottom 52 of the battery housing H, may include a shape that gradually becomes farther away from the bottom 52 in the radially outward direction. Thus, like the first section 501c of the plastic processing portion 50c1, the fastening member 50c3 has a structure that is inclined at a predetermined angle θ with respect to the bottom 52, and thus can provide sealing properties by crimping the terminal gasket 54.

[0188] In the second embodiment, the tip surface 50d of the protruding portion 50e also has a flat portion D. The flat portion D can protrude further in the axial direction than the fastening member 50c3. The flat portion D can also maintain its size and shape without being affected by the fastening of the fastening member 50c3.

[0189] 15 and 16, 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 preliminarily formed on the bottom 52 and the through-hole 53 of the battery housing H before the electrode terminal 50 is attached to the through-hole 53.

[0190] Optionally, in order to enhance the sealing property of the electrode terminal 50, a second sealing coating layer f2 may cover the externally exposed interface between the terminal gasket 54 and the bottom 52 of the battery housing H and / or the externally exposed interface between the fastening member 50c3 and the terminal gasket 54. The second sealing coating layer f2 may be formed by using a spray coating method after the installation 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 optional elements, not essential elements.

[0192] 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. The sealing coating layer (first sealing coating layer f1, second sealing coating layer f2) may be made of a material such as silicone resin, silicone acrylate, or polyamideimide, 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 diameter of the cylindrical battery divided by the height of the cylindrical battery) of greater than about 0.4.

[0195] Here, the form factor refers to a series of numbers indicating the diameter and height of a cylindrical battery. A 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 number 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 one embodiment of the present invention may be a generally cylindrical battery having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0197] Another embodiment of the battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0198] In yet another embodiment, the battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.436.

[0199] In yet another embodiment, the battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0200] In yet another embodiment, the battery may be a generally cylindrical battery having 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 taken 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 one embodiment includes a jelly-roll type electrode assembly 71 in which sheet-like first and second electrodes are wound with a separator interposed therebetween, and an uncoated portion 72 of the first electrode is exposed at the bottom and an uncoated portion 73 of the second electrode is exposed at the top.

[0204] In an embodiment, the first electrode may be a negative electrode and the second electrode may be a positive electrode, although of course the opposite is also possible.

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

[0206] In the illustration of the electrode assembly 71, only the uncoated portions 72 and 73 that are exposed and extended from the separator are shown in detail, and the winding structure of the first electrode, the second electrode and the separator are not shown.

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

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

[0209] The cylindrical battery 70 may also 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 to be insulative from the battery housing H. Desirably, the sealing body 74 may include a non-polarized 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, nickel, etc., and the sealing gasket 74b may be made of an insulating and elastic material such as polypropylene, polybutylene terephthalate, polyfluoroethylene, etc. However, the present invention is not limited by the material of the cap 74a and the sealing gasket 74b.

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

[0213] To secure the seal 74, the battery housing H may include a crimping portion 75 that extends and bends inside the battery housing H to wrap around and secure the periphery of the cap 74a together with a sealing gasket 74b.

[0214] Additionally, the battery housing H may include a beading 76 pressed into the interior of the battery housing H in the area adjacent the open end. The beading 76 supports the periphery of the seal 74, particularly the outer peripheral surface of the sealing gasket 74b, when the seal 74 is secured by the crimping 75.

[0215] The cylindrical battery 70 may further include a first current collector 78 welded to the uncoated portion 72 of the first electrode. The first current collector 78 is made of a conductive metal material such as aluminum, steel, or nickel. Preferably, at least a portion 78a of the periphery of the first current collector 78 that is not in contact with the uncoated 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. Alternatively, at least a portion 78a of the periphery of the first current collector 78 may be fixed to an inner circumferential surface 76a of the beading portion 76 adjacent to the crimping portion 75 by welding.

[0216] The cylindrical battery 70 may also include a second current collector 79 welded to the uncoated portion 73 of the second electrode. Desirably, at least a portion of the second current collector 79, for example, a central portion 79a, may be welded to the flat portion D of the electrode terminal 50.

[0217] Preferably, when welding the second current collector 79, a welding tool can be inserted through a cavity 80 present in the core of the electrode assembly 71 to reach the welding point of the second current collector 79. In addition, when the second current collector 79 is welded to the flat portion D of the electrode terminal 50, the electrode terminal 50 supports the welding area of ​​the second current collector 79, so that strong pressure can be applied to the welding area to improve the welding quality. In addition, since the flat portion D of the electrode terminal 50 has a wide area, a wide welding area can be secured. This reduces the contact resistance of the welding area, thereby reducing the internal resistance of the cylindrical battery 70. The face-to-face welding structure between the riveted electrode terminal 50 and the second current collector 79 is very useful for fast 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, so that the amount of heat generated in the current path can be reduced more than before.

[0218] When welding the flat portion D of the electrode terminal 50 to the second current collector 79, any one of laser welding, ultrasonic welding, spot welding, and resistance welding may be used. The area of ​​the flat portion D may be adjusted differently depending on the welding method, but is preferably 2 mm or more in terms of weld strength and ease of the welding process.

[0219] In one example, when the flat portion D and the second current collector 79 are welded by a laser 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 condition, the welding strength can be ensured and it is easy to insert a 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 ultrasonically welded in a circular pattern, it is preferable that the diameter of the flat portion D is 2 mm or more. When the diameter of the flat portion D satisfies the corresponding condition, the welding strength can be ensured, and it becomes easy to insert an ultrasonic welding tool into the cavity 80 of the electrode assembly 71 to perform the welding process.

[0221] 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 52, and between the inner circumferential surface 51a of the side wall of the battery housing H and the electrode assembly 71. Desirably, the insulator 81 may include 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) end of the electrode assembly 71.

[0222] Desirably, the uncoated portion 72 of the first electrode and / or the uncoated portion 73 of the second electrode may be bent from the outer periphery side of the electrode assembly 71 toward the core side to form bent surfaces at the upper and lower parts of the electrode assembly 71. Also, the first current collector 78 may be welded to the bent surface formed by bending the uncoated portion 72 of the first electrode, and the second current collector 79 may be welded to the bent surface formed by bending the uncoated portion 73 of the second electrode.

[0223] To relieve stress caused when the plain portions 72, 73 are folded, the first electrode and / or the second electrode may have an improved structure different from the conventional electrodes (see FIG. 1).

[0224] FIG. 17 is a plan view illustrating an example of the structure of an electrode 90 according to a preferred embodiment of the present invention.

[0225] Referring to FIG. 17, an electrode 90 includes a sheet-like electrode collector 91 made of a foil of a conductive material, an active material layer 92 formed on at least one surface of the electrode collector 91, and a plain portion 93 on a long side end of the electrode collector 91 where no active material is coated.

[0226] Preferably, the non-coating portion 93 may include a plurality of notched segments 93a. The plurality of segments 93a may be arranged in a plurality of groups, and the segments 93a in each group may have the same height (length in the Y direction) and / or width (length in the X direction) and / or spacing pitch. The number of segments 93a in each group may be more or less than that shown in the figure. The segments 93a may be trapezoidal, but may be modified to have a rectangle, parallelogram, semicircle, or semi-ellipse.

[0227] Preferably, the height of the divided segments 93a may increase stepwise from the core side toward the outer periphery side. Also, the core-side uncoated region 93' adjacent to the core side may not include the divided segments 93a, and the height of the core-side uncoated region 93' may be lower than the other uncoated regions.

[0228] Optionally, the electrode 90 may include an insulating coating layer 94 covering the boundary between the active material layer 92 and the uncoated portion 93. The insulating coating layer 94 includes an insulating polymer resin, and may optionally further 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 the active material layer 92 through the separator, and serves to structurally support the folding of the divided piece 93a. Therefore, when the electrode 90 is wound into an electrode assembly, it is preferable that at least a portion of the insulating coating layer 94 is exposed to the outside through the separator.

[0229] FIG. 18 is a cross-sectional view of an electrode assembly 100 in which a division structure of the uncoated portion of an electrode 90 according to an embodiment of the present invention is applied to a first electrode and a second electrode, cut 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 ease of explanation, the protruding structure of the uncoated portions 72 and 73 extending outward from the separator is shown in detail, and the winding structure of the first electrode, second electrode, and separator is not shown. The uncoated portion 72 protruding downward is extended from the first electrode, and the uncoated portion 73 protruding upward is extended from the second electrode.

[0231] The pattern in which the height of the uncoated portions 72, 73 varies is illustrated diagrammatically. That is, the height of the uncoated portions 72, 73 may vary irregularly depending on the cutting position of the cross section. As an example, if a side edge of the trapezoidal segment 93a is cut, the height of the uncoated portions in the cross section will be lower than the height of the segment 93a. Therefore, it should be understood that the height of the uncoated portions 72, 73 shown in the drawing showing the cross section of the electrode assembly 100 corresponds to the average height of the uncoated portions included in each winding turn.

[0232] The uncoated portions 72, 73 may be folded from the outer periphery side of the electrode assembly 100 to the core side as shown in FIG. 19. In FIG. 18, the folded portion 101 is indicated by a dashed line box. When the uncoated portions 72, 73 are folded, the radially adjacent segments overlap each other to form folded surfaces 102 at the upper and lower parts of the electrode assembly 100. At this time, the core side uncoated portion (93' in FIG. 17) is not folded due to its low height, and the height h of the innermost folded segment is equal to or smaller than the radial length r of the winding region formed by the core side uncoated portion 93' without a segment structure. Therefore, the cavity 80 in the core of the electrode assembly 100 is not closed by the folded segment. If the cavity 80 is not closed, the electrolyte injection process is not hindered 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 together.

[0233] In the cylindrical battery 70 according to the embodiment of the present invention, the cap 74a of the sealed body 74 does not have 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 multiple batteries in series and / or 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. This increases the number of batteries that can be mounted in the same space, thereby improving 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 may be any active material known in the art without any limitations.

[0235] In one example, the positive electrode active material has the general chemical formula A[A x M y ]O 2+z (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; 0≦x, 1≦x+y≦2, −0.1≦z≦2; x, y, z, and the stoichiometric coefficients of the components included in M ​​are selected such that the compound 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 may be represented by 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 halogen elements, optionally including F; <a≦2、0≦x≦1、0≦y<1、0≦z<1;a、x、y、z、M 1 , M 2 and M 3 wherein the stoichiometric coefficients of the components included are selected to maintain electroneutrality of the compound), or lithium metal phosphate, represented by Li3M2(PO4)3, where M comprises 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 include primary particles and / or secondary particles formed by agglomeration of the primary particles.

[0239] In one example, the negative electrode active material may be a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO2 and SnO2 having a potential of less than 2 V may also be used as the negative electrode active material. The carbon material may be either low-crystalline carbon or high-crystalline carbon.

[0240] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., used alone or in combination. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of a high melting point glass fiber, a polyethylene terephthalate fiber, etc.

[0241] At least one surface of the separation membrane may include a coating layer of inorganic particles. Alternatively, the separation membrane itself may be made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound with a binder such that there is an interstitial volume between adjacent particles.

[0242] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles may be made 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 is A + B - In this case, the salt may have the structure: + Li + , Na + , K + or a combination thereof. - is F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , AlO4 - , AlCl4 - , PF6 - , SbF6 - , AsF6 - , BF2C2O4 - , BC4O8 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , CF3SO3 - , C4F9SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO -, (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N - The anion includes one or more anions selected from the group consisting of:

[0244] The electrolyte may be dissolved in an organic solvent for use. The organic solvent may be 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.

[0245] The cylindrical battery according to the above-described embodiments can be used to manufacture a battery pack.

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

[0247] 20, a battery pack 200 according to an embodiment of the present invention includes an assembly of electrically connected cylindrical batteries 201, and a pack housing 202 that accommodates the cylindrical batteries 201. The cylindrical batteries 201 may be the batteries according to the above-described embodiments. For convenience of illustration, components such as bus bars for electrical connection of the cylindrical batteries 201, a cooling unit, and external terminals are not shown.

[0248] The battery pack 200 may be installed in a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, including a four-wheeled vehicle or a two-wheeled vehicle.

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

[0250] 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 from the battery pack 200 according to an embodiment of the present invention.

[0251] The above-described embodiments are illustrative in all respects and are not limiting, and the scope of the present invention is represented by the appended claims rather than the above detailed description. The meaning and scope of the claims, as well as all modifications and variations derived from the equivalent concept, are to be interpreted as being included in the scope of the present invention.

[0252] Although the present invention has been described with reference to the drawings illustrating the present invention, it is obvious that the present invention is not limited to the embodiments and drawings shown in the present specification, and that various modifications may be made by those skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not clearly stated in the description of the embodiments, it goes without saying that the effects that can be predicted by the corresponding configuration should also be recognized.

[0253] 10 positive electrode 11 Negative electrode 12 Separation membrane 20 Current collector 21 Active material 22 Plain area 30 Current collector 31 Current collector 40 Cylindrical battery, Tables Cylindrical battery 41 Battery housing 42 Sealed body 43 Crimping section 44 Beading section 45 Lead 46 Insulators 50 electrode terminal 51 Side wall 52 Bottom 53 Through hole 54 Terminal gasket 55 Groove 56 Inner Edge 57 Opposite Surface 70 Cylindrical Battery 71 Electrode assembly 72 Plain section 73 Plain section 74 Sealed body 75 Crimping section 76 Beading section 77 Venting Notch 78 First current collector 79 Second current collector 80 hollow 81 Insulators 90 electrodes 91 Electrode current collector 92 Active material layer 93 Plain area 94 Insulating coating layer 100 electrode assembly 101 Bent part 102 Bent surface 200 Battery Pack 201 Cylindrical Battery 202 Pack Housing 501 1st Section 502 Section 2

Claims

1. a battery housing including a side wall having an open end on one side thereof and a bottom portion integrally connected to the other side of the side wall and having a through hole; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along an outer surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from an inner surface of the bottom along an axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, The outer surface of the bottom has an opposite polarity to the electrode terminal, A fixing structure for an electrode terminal, in which a current collector is bonded to the tip surface.

2. A fastening groove is formed on the outer circumferential surface of the protrusion and recessed in the centripetal direction, The electrode terminal fixing structure according to claim 1 , wherein the fastening member is fitted into the fastening groove and fixed thereto.

3. 3. The electrode terminal fixing structure according to claim 2, wherein the fastening groove has a shape of a male thread, and the fastening member is a nut having a female thread formed thereon to be fastened to the male thread.

4. A battery housing having an open end on one side and a bottom having a through hole on the other side; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, A fastening groove is formed on the outer circumferential surface of the protrusion and recessed in the centripetal direction, The fastening member is fitted into the fastening groove and fixed thereto, The fastening groove is an O-shaped groove, and the fastening member is a C-shaped ring fitted into the O-shaped groove.

5. A battery housing having an open end on one side and a bottom having a through hole on the other side; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, A fixing structure for an electrode terminal, wherein a surface of the fastening member facing the bottom portion includes a sidewall surface that gradually becomes farther from the bottom portion toward the outside in the radial direction.

6. A fastening groove is formed on the outer peripheral surface of the protrusion along the circumferential direction and recessed in the centripetal direction, The fastening member is fitted into the fastening groove and fixed thereto, 6. The electrode terminal fixing structure according to claim 5, wherein the side wall surface presses the terminal gasket toward a bottom of the battery housing when the fastening member is coupled to the fastening groove.

7. The electrode terminal fixing structure according to claim 1 , further comprising a first sealing coating layer formed on the interface between the terminal gasket and the bottom of the battery housing.

8. The electrode terminal fixing structure according to claim 7 , wherein the first sealing coating layer comprises a silicone resin, a silicone acrylate, or a polyamideimide.

9. A battery housing having an open end on one side and a bottom having a through hole on the other side; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, The electrode terminal fixing structure further includes a second sealing coating layer covering an externally exposed interface between the fastening member and the terminal gasket.

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

11. The electrode terminal fixing structure according to claim 9 or 10, wherein the second sealing coating layer comprises a silicone resin, a silicone acrylate or a polyamideimide.

12. 2 . The electrode terminal fixing structure according to claim 1 , wherein the tip end surface protrudes further in the axial direction of the battery housing than the enlarged diameter portion with respect to a bottom surface of the battery housing.

13. The electrode terminal fixing structure according to claim 1 , wherein the tip surface includes a flat portion having a flat surface.

14. A battery housing having an open end on one side and a bottom having a through hole on the other side; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, The fastening member has a first section that extends in a centrifugal direction from the protrusion and gradually becomes farther from a bottom of the battery housing.

15. The electrode terminal fixing structure according to claim 14 , wherein in the first section, an angle between the surface of the fastening member facing the bottom and the bottom is greater than 0° and not greater than 60°.

16. 2 . The electrode terminal fixing structure according to claim 1 , wherein the diameter of the enlarged portion in a cross section taken in a direction perpendicular to a central axis of the battery housing is larger than the diameter of the through hole.

17. A battery housing having an open end on one side and a bottom having a through hole on the other side; An electrode terminal fixed to the bottom portion; a terminal gasket interposed between the electrode terminal and the bottom; A fixing structure for an electrode terminal, comprising: The electrode terminal is a neck portion having a cross section smaller than a cross section 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 a cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an expanded diameter portion extending in a centrifugal direction from the protruding portion; a tip surface provided at an axial end of the protrusion; Equipped with the enlarged diameter portion is a fastening member physically coupled to an outer circumferential surface of the protrusion, A fixing structure for an electrode terminal, wherein the diameter of the enlarged diameter portion, in a cross section taken in a direction perpendicular to the central axis of the battery housing, gradually increases the farther from the bottom of the battery housing.

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

19. an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, the electrode assembly including an uncoated portion of the first electrode and an uncoated portion of the second electrode extending from both side ends and exposed to the outside of the separator; a battery housing having an open end at one side thereof, the battery housing receiving the electrode assembly through the open end and electrically connected to the first electrode; an electrode terminal electrically connected to the second electrode, the electrode terminal being attached through a through hole formed in a bottom of the battery housing so as not to come into contact with an inner wall of the through hole, the electrode terminal comprising: a neck portion having a cross section smaller than the cross section 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 the cross section of the through hole and extending along one surface of the bottom portion; a protrusion connected to the other end of the neck portion and extending from the other surface of the bottom portion along the axial direction of the battery housing; an enlarged diameter portion extending in a centrifugal direction from the protrusion; and a tip surface provided at an axial end of the protrusion. Equipped with The enlarged diameter portion is an electrode terminal that is a fastening member that is physically coupled to an outer peripheral surface of the protrusion; a terminal gasket interposed between the electrode terminal and the through hole; a seal sealing an open end of the battery housing such that the open end is insulative from the battery housing.

20. A fastening groove is formed on the outer circumferential surface of the protrusion and recessed in the centripetal direction, The battery of claim 19 , wherein the fastening member is fitted into the fastening groove and fixed thereto.

21. 21. The battery of claim 20, wherein the fastening groove has a shape of a male thread, and the fastening member is a nut having a female thread formed thereon to fasten with the male thread.

22. 21. The battery of claim 20, wherein the fastening groove is an O-shaped groove, and the fastening member is a C-shaped ring that fits into the O-shaped groove.

23. 21. The battery of claim 20, wherein a surface of the fastener facing the base includes a sidewall surface that gradually becomes farther away from the base in a radially outward direction.

24. 24. The battery of claim 23, wherein the sidewall surface presses the terminal gasket against a bottom of the cell housing when the fastener is engaged with the fastener groove.

25. 20. The battery of claim 19, further comprising a first sealing coating layer formed at an interface between the terminal gasket and the bottom of the cell housing.

26. 26. The battery of claim 25, wherein the first sealing coating layer comprises a silicone resin, a silicone acrylate, or a polyamideimide.

27. 20. The battery of claim 19, further comprising a second sealing coating layer covering an externally exposed interface between the fastener and the terminal gasket.

28. 28. The battery of claim 27, wherein the second sealing coating layer covers an externally exposed interface between the terminal gasket and the bottom.

29. 28. The battery of claim 27, wherein the second sealing coating layer comprises a silicone resin, a silicone acrylate, or a polyamideimide.

30. the battery housing includes a beading portion pressed into the inside of the battery housing in an area adjacent the open end; 20. The battery of claim 19, wherein the seal includes a non-polarized cap and a sealing gasket interposed between a periphery of the cap and an open end of the cell housing.

31. 31. The battery of claim 30, wherein the battery housing further includes a crimping portion that extends and is folded inwardly of the battery housing to wrap around and secure the periphery of the cap together with the sealing gasket.

32. a first current collector coupled to the uncoated portion of the first electrode, 32. The battery of claim 31, wherein at least a portion of the periphery of the first current collector that is not in contact with the uncoated portion of the first electrode is interposed between the beading portion and the sealing gasket and fixed by the crimping portion.

33. The battery of claim 32 , wherein at least a portion of a periphery of the first current collector is fixed to an inner circumferential surface of the beading portion adjacent to the crimping portion through welding.

34. a second current collector coupled to the uncoated portion of the second electrode, The battery according to claim 19 , wherein at least a portion of the second current collector is welded to a tip surface of the electrode terminal.

35. 35. The battery of claim 34, further comprising an insulator interposed between the second current collector and an inner surface of the bottom of the battery housing, and between an inner peripheral surface of the side wall of the battery housing and the electrode assembly.

36. 20. The battery of claim 19, wherein a form factor ratio of the diameter of the battery divided by the height of the battery is greater than 0.

4.

37. 20. The battery of claim 19, wherein the AC resistance measured between the electrode terminals of the battery and the outer surface of the bottom of the battery housing is 4 mΩ or less.

38. 38. A battery pack comprising a plurality of batteries according to any one of claims 19 to 37.

39. 40. A motor vehicle comprising the battery pack of claim 38.

Images