Battery cells, battery packs containing battery cells, and automobiles

Abstract

A battery cell according to one embodiment of the present invention is an electrode assembly comprising a first electrode and a second electrode, and a separation membrane interposed between them, which is wound around a winding axis to define a core and an outer surface, wherein the first electrode includes an electrode assembly including a first plain portion in which an active material layer is not coated along the winding direction, a housing including an opening on one side and configured to accommodate the electrode assembly through the opening, a current collector including a rim portion positioned on the top of the electrode assembly, a plain portion coupling portion extending inward from the rim portion and coupled to the first plain portion, and a terminal coupling portion located in the center away from the plain portion coupling portion and exposed to the outside of the housing, a terminal that penetrates a closed portion of the housing located on the opposite side of the opening and is exposed to the outside of the housing and coupled to the terminal coupling portion, and a terminal block configured to be coupled to the inside of the current collector.

Description

Technical Field

[0001] The present invention relates to a battery cell, a battery pack including the battery cell, and an automobile. This application claims priority based on Korean Patent Application No. 10-2024-0021860 filed on February 15, 2024, and Korean Patent Application No. 10-2024-0067973 filed on May 24, 2024, and all the contents disclosed in the specifications and drawings of the applications are incorporated into this application.

Background Art

[0002] Secondary batteries that are easy to apply according to product groups and have electrical characteristics such as high energy density are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source. Such secondary batteries have not only the main advantage of significantly reducing the use of fossil fuels but also the advantage of generating no by-products due to energy use, and thus are attracting attention as a new energy source for environmental consideration and improving energy efficiency.

[0003] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, nickel zinc batteries, etc. The operating voltage of such a unit secondary battery cell, that is, a unit battery cell, is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a plurality of battery cells may be connected in series to form a battery pack. Also, depending on the charge / discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to form a battery pack. Therefore, the number of battery cells included in the battery pack can be variously set according to the required output voltage and / or charge / discharge capacity.

[0004] On the other hand, conventional cylindrical battery cells are manufactured by welding (CRW (Cathode Rivet Welding)) the positive electrode rivet terminal to the positive electrode current collector plate, which is welded to the electrode assembly. In this CRW welding process, the rivet terminal and the positive electrode current collector plate are welded together by inserting a welding horn tip into a hole formed in the winding center of the electrode assembly. However, the CRW process introduces various constraints into secondary battery development. For example, spatter generated during CRW welding can cause damage to the separator membrane and reduce battery capacity and lifespan. Furthermore, because it is difficult to reduce the diameter of the CRW welding horn tip, there are limitations to increasing the energy density of the electrode assembly. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, one objective of the present invention is to prevent welding spatter from flowing into the battery housing by performing terminal welding outside the battery housing.

[0006] Another objective of this invention is to minimize damage to the separation membrane and improve battery life.

[0007] In another embodiment, the present invention also aims to improve energy density by increasing the number of turns in the electrode assembly.

[0008] However, the technical problems that this invention aims to solve are not limited to those mentioned above, and other problems not mentioned will be clearly understood by an ordinary person of the art from the description of the invention below. [Means for solving the problem]

[0009] A battery cell according to one embodiment of the present invention for solving the above problems is an electrode assembly in which a core and an outer surface are defined by winding a first electrode, a second electrode, and a separator membrane interposed between them around a winding axis, wherein the first electrode includes an electrode assembly including a first plain portion in which an active material layer is not coated along the winding direction; a housing including an open portion on one side and configured to accommodate the electrode assembly through the open portion; a current collector including an edge portion disposed on the upper part of the electrode assembly, a plain portion coupling portion extending inward from the edge portion and coupled to the first plain portion, and a terminal coupling portion located in the center away from the plain portion coupling portion and exposed to the outside of the housing; a terminal that penetrates a closed portion of the housing located on the opposite side of the open portion and is exposed to the outside of the housing and coupled to the terminal coupling portion; and a terminal block configured to be coupled to the inside of the current collector.

[0010] In one embodiment of the present invention, the current collector, the terminal, and the terminal block may be configured to be welded together outside the housing.

[0011] The coupling surface where the current collector, the terminal, and the terminal block are joined can form a flat portion parallel to the closed portion of the housing.

[0012] In another embodiment of the present invention, the terminal coupling portion may include a first part extending parallel to the closing portion and a second part extending perpendicularly from the first part toward the outside of the housing.

[0013] The second part may extend in a direction parallel to the winding axis of the electrode assembly.

[0014] In yet another embodiment of the present invention, the second part may be configured to have a hollow pipe shape inside.

[0015] Furthermore, an injection hole may be provided in the first part that is concentric with the second part and has a diameter less than or equal to the inner diameter of the second part.

[0016] Furthermore, a support portion may be formed at the bottom of the second part to secure the lower surface of the terminal block.

[0017] In one embodiment of the present invention, the outer diameter of the terminal block may be the same as the inner diameter of the second part.

[0018] In the present invention, the terminal block may be cylindrical in shape, and the outer circumference of the upper part may be chamfered to form a tapered surface.

[0019] In the present invention, a weld bead can be formed along the second part on the joint surface where the current collector, the terminal, and the terminal block are joined.

[0020] In another embodiment of the present invention, the terminal may penetrate the center of the closing portion.

[0021] In yet another embodiment of the present invention, the terminal may include a terminal exposure portion exposed to the outside of the housing, a terminal insertion portion located inside the housing and penetrating the closing portion of the housing, and a terminal connection portion that connects the terminal exposure portion and the terminal insertion portion and penetrates the housing.

[0022] For example, the terminal connection portion may be configured to have a hollow pipe shape inside.

[0023] The outer diameter of the second part may be smaller than or the same as the inner diameter of the terminal connection portion.

[0024] In one embodiment of the present invention, an insulating gasket interposed between the housing and the terminal may be provided on the closing portion side of the housing.

[0025] Here, the insulating gasket may include a gasket exposure portion interposed between the terminal exposure portion and the housing, and a gasket insertion portion interposed between the terminal insertion portion and the housing.

[0026] On the one hand, the present invention provides a battery pack including at least one battery cell according to the present invention.

[0027] Furthermore, the present invention provides a motor vehicle including at least one battery pack according to the present invention.

Advantages of the Invention

[0028] According to the present invention, by performing terminal welding outside the battery housing, it is possible to prevent welding spatter from flowing into the interior of the battery housing.

[0029] Also, according to the present invention, damage to the separator can be minimized and the battery life can be improved.

[0030] Also, in another aspect, according to the present invention, by increasing the number of winding turns of the electrode assembly, the energy density can be improved.

[0031] However, the effects obtained by the present invention are not limited to the above-described effects, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0032] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention. Therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0033] [Figure 1] It is a diagram for explaining a battery cell according to an embodiment of the present invention. [Figure 2] It is a longitudinal sectional view of the battery cell of FIG. 1. [Figure 3]Figure 1 is an enlarged cross-sectional view of the upper part of the battery cell, illustrating the process by which the terminal block is coupled to the current collector. [Figure 4] This is an enlarged cross-sectional view of the upper part of the battery cell in Figure 1, illustrating the state in which the terminal block is connected to the current collector. [Figure 5] This is a diagram illustrating a current collector according to one embodiment of the present invention. [Figure 6] This is a diagram illustrating a current collector according to another embodiment of the present invention. [Figure 7] This is a diagram illustrating a current collector according to yet another embodiment of the present invention. [Figure 8] This is a diagram illustrating the terminals related to one embodiment of the present invention. [Figure 9] This is a diagram illustrating a terminal block relating to one embodiment of the present invention. [Figure 10] This is a magnified cross-sectional view of the upper part of the battery cell in Figure 1. [Figure 11] This is a magnified view of a portion of Figure 10. [Figure 12] This is a diagram illustrating the region to which welding is applied in a battery cell according to one embodiment of the present invention. [Figure 13] This figure illustrates the region to which welding is applied in a battery cell according to another embodiment of the present invention. [Figure 14] This is a top view of a battery cell showing a state in which welding has been performed on the battery cell according to another embodiment of the present invention. [Figure 15] This figure illustrates a terminal block according to another embodiment of the present invention. [Figure 16] Figure 15 shows the terminal block inserted into the second part of the current collector shown in Figure 7. [Figure 17] This diagram illustrates the battery pack, including the battery cells shown in Figure 1. [Figure 18] Figure 17 is a diagram illustrating an automobile including a battery pack. [Modes for carrying out the invention]

[0034] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their usual and dictionary sense, but rather in accordance with the technical ideas of the present invention, in accordance with the principle that the inventor himself may appropriately define the concepts of terms in order to best describe the invention. Therefore, it should be understood that the configurations shown in the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entirety of the technical ideas of the present invention, and that there may be a variety of equivalents and modifications that can be substituted for them at the time of this application.

[0035] Furthermore, for the sake of understanding the invention, the accompanying drawings are not shown to actual scale, and the dimensions of some components may be exaggerated. Also, the same component may be assigned the same reference numeral in different embodiments.

[0036] The statement that two comparison objects are identical means that they are "substantially identical." Therefore, substantially identical objects may include those with deviations considered low in this industry, for example, deviations of 5% or less. Also, in a given domain, the uniformity of a parameter may mean that it is uniform in terms of the average.

[0037] While terms like "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited to these. These terms are used solely to distinguish one component from another, and it goes without saying that, unless otherwise stated, the first component is also the second component.

[0038] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0039] To say that any configuration is placed "above (or below)" or "above (or below)" a component means not only that the configuration is placed in contact with the upper (or lower) surface of the above component, but that another configuration may be interposed between the above component and any configuration placed on (or below) it.

[0040] Furthermore, when it is stated that one component is “linked,” “joined,” or “connected” to another component, please understand that while the above components may be directly linked or connected to each other, there may also be other components “interposed” between them, or each component may be “linked,” “joined,” or “connected” through other components.

[0041] Throughout the specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or above and D or below unless otherwise specified.

[0042] For the sake of explanation, in this specification, the direction along the longitudinal direction of the winding axis of an electrode assembly wound in a jelly-roll shape is referred to as the axial direction (Z). The direction surrounding the winding axis is referred to as the circumferential direction or around direction (X). The direction approaching or moving away from the winding axis is referred to as the radial direction. Of these, the direction approaching the winding axis is specifically referred to as the centripetal direction, and the direction moving away from the winding axis is referred to as the centrifugal direction.

[0043] Figure 1 is a diagram illustrating a battery cell according to one embodiment of the present invention, and Figure 2 is a longitudinal cross-sectional view of the battery cell in Figure 1.

[0044] Referring to Figures 1 and 2, a battery cell 1 according to one embodiment of the present invention may be, for example, a cylindrical battery cell 1. The cylindrical battery cell 1 includes an electrode assembly 10, a housing 20, a current collector 30, terminals 40, and a terminal block 50. In addition to the components described above, the cylindrical battery cell 1 may further include an insulating gasket G2 and / or an insulator 60. The present invention is not limited by the shape of the battery and is applicable to other shapes of batteries, such as prismatic batteries.

[0045] The electrode assembly 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separation membrane interposed between the first electrode and the second electrode. The first electrode is either a positive or negative electrode, and the second electrode corresponds to an electrode having the opposite polarity to the first electrode.

[0046] The electrode assembly 10 may have, for example, a jelly roll structure. That is, the electrode assembly 10 can be manufactured by winding a laminate formed by stacking a first electrode current collector and a second electrode current collector, both having sheet-like structures, at least once with a separator membrane interposed between them, in one direction with respect to the winding center C. In this case, an additional separator membrane may be provided on the outer surface of the electrode assembly 10 for insulation from the housing 20. The present invention is applicable without limitation to any wound electrode assembly structure known in the art.

[0047] The first electrode includes a first electrode current collector and a first electrode active material coated on one or both sides of the first electrode current collector. The first electrode includes a first blank portion in which the active material layer is not coated along the winding direction. That is, a blank portion is present at one end of the first electrode current collector in the width direction (parallel to the Z-axis) where the first electrode active material is not coated. The blank portion that functions as the first electrode tab will be referred to below as the first blank portion 11. The first blank portion 11 is provided at the top of the electrode assembly 10 in the height direction (parallel to the Z-axis) housed in the housing 20. That is, the first electrode current collector includes a first blank portion 11 at the end of its long side where the active material layer is not coated and is exposed to the outside of the separator film, and a part of the first blank portion 11 is used as an electrode tab itself. The first blank portion 11 may be, for example, a positive electrode tab. In this case, the first electrode is a positive electrode plate.

[0048] On the other hand, at least a portion of the first blank section 11 may include a plurality of segmented pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segmented pieces may be bent along the radial direction of the electrode assembly 10. The bent plurality of segmented pieces may overlap in multiple layers. In this case, the blank section joining portion 32, described later, can be joined to the region where the plurality of segmented pieces overlap in multiple layers.

[0049] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both sides of the second electrode current collector. At the other end of the second electrode current collector in the width direction (parallel to the Z-axis), there is a blank area where the second electrode active material is not coated. The blank area that functions as a second electrode tab will be referred to below as the second blank area 12. The second blank area 12 is located at the bottom of the electrode assembly 10 housed in the housing 20 in the height direction (parallel to the Z-axis). That is, the second electrode current collector includes a second blank area 12 that is exposed to the outside of the separation film and whose long side ends are not coated with the active material layer, and at least a portion of the second blank area 12 is used as an electrode tab by itself. The second blank area 12 may be, for example, a negative electrode tab. In this case, the second electrode is a negative electrode plate.

[0050] On the other hand, at least a portion of the second plain section 12 may include a plurality of segmented pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segmented pieces may be bent along the radial direction of the electrode assembly 10. The bent plurality of segmented pieces may overlap in multiple layers.

[0051] The first blank section 11 and the second blank section 12 extend in opposite directions along the height direction (parallel to the Z-axis) of the cylindrical battery cell 1. The first blank section 11 extends toward the closed portion of the housing 20, and the second blank section 12 extends toward the open portion of the housing 20.

[0052] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be used without limitation as long as they are active materials well known in the art. Preferably, the battery cell 1 may be, for example, a cylindrical secondary battery with a form factor ratio (height to diameter ratio) greater than about 0.4. Preferably, the diameter of the cylindrical secondary battery is 40 mm to 50 mm and the height is 60 mm to 130 mm. The form factor of the battery cell 1 may be, for example, 46110, 4875, 48110, 4880, or 4680.

[0053] Referring to Figures 1 and 2, the housing 20 is a substantially cylindrical housing with an open portion formed on one side, and is made of a conductive material such as metal. In the illustrated example, the open portion is formed at the lower end of the housing 20 in the Z-axis direction. As the material of the housing 20, for example, iron (steel), stainless steel (SUS), or nickel-plated iron can be used. The upper surface located on the opposite side of the open portion is called the closed portion. In the illustrated example, the closed portion is formed at the upper end of the housing 20 in the Z-axis direction. The side wall portion and the closed portion of the housing 20 may be formed integrally. Alternatively, the side wall portion and the closed portion of the housing 20 may be provided separately and joined to each other by welding or the like. The upper surface of the housing 20 (the surface parallel to the XY plane), i.e., the outer surface 20a of the closed portion, may have a substantially flat shape. The housing 20 houses the electrode assembly 10 through the open portion formed on one side, and also houses the electrolyte together with it.

[0054] The housing 20 is electrically connected to the electrode assembly 10. For example, the housing 20 is electrically connected to the second blank portion 12 of the electrode assembly 10. In this case, the housing 20 has the same polarity as the second blank portion 12.

[0055] Figure 3 is an enlarged cross-sectional view of the upper part of the battery cell in Figure 1, illustrating the process by which the terminal block is coupled to the current collector. Figure 4 is an enlarged cross-sectional view of the upper part of the battery cell in Figure 1, illustrating the state in which the terminal block is coupled to the current collector. Figure 5 is a diagram illustrating a current collector according to one embodiment of the present invention, and Figure 6 is a diagram illustrating a current collector according to another embodiment of the present invention.

[0056] Referring to Figures 3 and 4, the current collector 30 is coupled to the upper part of the electrode assembly 10. The current collector 30 is made of a conductive metallic material and is connected to the first blank portion 11. The current collector 30 can be coupled to a coupling surface formed by bending the end of the first blank portion 11 in a direction parallel to the current collector 30.

[0057] Referring to Figures 3 and 4, the current collector 30 can be coupled to the upper part of the electrode assembly 10. Alternatively, the current collector 30 can be coupled to the terminal 40. That is, the current collector 30 electrically connects the first blank portion 11 of the electrode assembly 10 to the terminal 40. The current collector 30 is made of a conductive metallic material. The current collector 30 may be made of the same metal as the first electrode current collector, or a material that can be easily welded to it. For example, it may be aluminum (Al) or an aluminum alloy, nickel or a nickel alloy, iron, stainless steel (SUS), or a composite material thereof.

[0058] Referring to Figures 5 and 6 in conjunction with Figures 3 and 4, the current collector 30 includes an edge portion 31, a blank portion coupling portion 32, and a terminal coupling portion 33. The edge portion 31 is positioned on the upper part of the electrode assembly 10 and may have a substantially rim shape with an empty space S formed inside. In the drawings of the present invention, only the case in which the edge portion 31 has a substantially circular rim shape is shown, but this does not limit the present invention. The edge portion 31 may have a substantially square rim shape, a hexagonal rim shape, an octagonal rim shape, or other rim shapes, different from those shown. The blank portion coupling portion 32 may extend inward from the edge portion 31 and be coupled to the first blank portion 11.

[0059] The terminal coupling portion 33 is located inside the edge portion 31, separated from the plain portion coupling portion 32. The terminal coupling portion 33 can be joined to the terminal 40 and / or terminal block 50, which will be described later, by welding. The terminal coupling portion 33 may be located, for example, approximately in the center of the inner space surrounded by the edge portion 31. The terminal coupling portion 33 may be positioned in a location corresponding to a hole formed in the winding center C of the electrode assembly 10. The terminal coupling portion 33 is configured to be exposed to the outside of the housing 20.

[0060] Referring to Figures 1 to 4, the terminal 40 is made of a conductive metallic material. For example, aluminum can be used as the material for the terminal 40. When the material of the terminal 40 is aluminum, processing is made easier during riveting as described later, and 10-series aluminum, which has relatively low electrical resistance, can be used. The terminal 40 penetrates the closed portion of the housing 20, that is, the surface located opposite the open portion of the housing 20 (a surface parallel to the XY plane). For example, the terminal 40 may be configured to penetrate the center of the closed portion. The terminal 40 is electrically connected, for example, to the first blank portion 11 of the electrode assembly 10. In this case, the terminal 40 has a first polarity. Therefore, the terminal 40 can function as a first electrode terminal in the cylindrical battery cell 1 of the present invention. When the terminal 40 has a first polarity in this way, the terminal 40 is electrically insulated from the housing 20 which has a second polarity. On the other hand, the terminal 40 is connected to the terminal coupling portion 33 of the current collector 30 in the region exposed to the outside of the housing 20.

[0061] On the other hand, in the present invention, the outer surface 20a of the closed portion of the housing 20 can function as a second electrode terminal. The battery cell 1 according to the present invention has a structure in which the terminal 40 exposed in the closed portion of the housing 20 can be used as a first electrode terminal, and the remaining area of ​​the closed portion excluding the area occupied by the terminal 40 can be used as a second electrode terminal. Therefore, the battery cell 1 according to the present invention can connect both the positive and negative electrodes in one direction when electrically connecting multiple battery cells 1, thus simplifying the electrical connection structure. Furthermore, the battery cell 1 according to the present invention has a structure in which most of the closed portion of the housing 20 can be used as an electrode terminal, which has the advantage of providing a sufficient area for welding components for electrical connection.

[0062] Referring to Figures 3 and 4, the terminal block 50 may be a structure having a substantially cylindrical shape. The terminal block 50 may also be made of a conductive metallic material. The material of the terminal block 50 may be the same as that of the terminal 40, for example. For example, aluminum may be used.

[0063] Referring to Figures 3 and 4, the terminal block 50 may be configured to be coupled inside the current collector 30. That is, a portion of the current collector 30 may be exposed to the outside of the housing 20, and the exposed portion of the current collector 30 may have a roughly cylindrical shape with an open interior. In this case, the terminal block 50 may be inserted into the open interior. That is, the outer diameter of the terminal block 50 may be configured to be the same as the inner diameter of the terminal coupling portion 33 of the current collector 30. More specifically, the outer diameter of the terminal block 50 may be configured to be the same as the inner diameter of the second part 332 of the current collector 30, which will be described later. Alternatively, the outer diameter of the terminal block 50 may be configured to be slightly larger than the inner diameter of the terminal coupling portion 33. In this case, the terminal block 50 may be pushed and fitted inside the terminal coupling portion 33 of the current collector 30. Therefore, after being inserted into the empty space of the terminal coupling portion 33, the terminal block 50 can be fixed in a fixed position without moving in the vertical direction. Subsequently, the terminal coupling portion 33 and the terminal block 50 are joined by welding. However, even before welding, the terminal block 50 does not move in the winding axis direction, which allows for smooth welding.

[0064] According to the structure of the present invention as described above, the current collector 30, terminal 40, and terminal block 50 can all be exposed to the outside of the housing 20. This allows the current collector 30, terminal 40, and terminal block 50 to be welded together outside the housing 20. By connecting the terminal block 50 to the terminal coupling portion 33 of the current collector 30, the terminal 40, the current collector 30, and the terminal block 50 can be electrically connected.

[0065] For example, in conventional battery cell structures, the welding horn tip had to be inserted into a hole formed at the winding center of the electrode assembly to weld the current collector and terminals. Furthermore, conventional designs suffered from problems such as damage to the separation membrane due to spatter generated during welding, and a reduction in battery capacity and lifespan. Additionally, because it was difficult to reduce the diameter of the welding horn tip during welding, a certain diameter had to be maintained for the hole formed at the winding center of the electrode assembly, which limited the ability to increase energy density.

[0066] However, the current collector 30 and terminal 40 of the battery cell 1 according to the embodiment of the present invention differ from the current collector and terminal structure of conventional battery cells. According to the above-described structure of the present invention, the current collector 30, terminal 40, and terminal block 50 can be welded outside the housing 20. Because welding can be performed outside the housing 20 due to the structural modification of the current collector 30 and terminal 40, even if spatter is generated during welding, the spatter does not flow into the inside of the battery, and the separation membrane is not damaged. Furthermore, the problem of reduced battery capacity and lifespan can be solved. Moreover, according to the above-described structure of the present invention, because the current collector 30, terminal 40, and terminal block 50 are welded outside the housing 20, it is not necessary to insert the welding horn tip inside the electrode assembly 10, and the diameter of the hole formed in the winding center C of the electrode assembly 10 can be reduced, thereby increasing the number of windings of the electrode assembly 10 and improving the energy density.

[0067] Furthermore, according to the present invention, since the current collector 30, terminal 40, and terminal block 50 are welded to the outside of the housing 20, various welding methods such as laser welding and ultrasonic welding can be used.

[0068] When using ultrasonic welding, the horn needs to contact the contact area and vibrate. In conventional methods where welding is performed inside the housing, the horn needs to be longer than the length of the hole formed at the winding center, so there is a high risk of horn damage if strong vibrations occur in a linear or zigzag direction. Considering this, a method in which the horn rotates can also be applied, but even in this case, there are problems such as the generation of many burrs and difficulty in confirming whether there are any unjointed areas. Furthermore, in the case of ultrasonic welding, problems can also occur due to foreign matter (metal shavings) generated during welding. In the present invention, since welding is performed outside the housing 20, ultrasonic welding can be performed using a short horn, strong vibrations can be applied, and the area to be joined by welding can be observed from the outside. This not only allows welding without unjointed areas, but also prevents foreign matter generated during welding from flowing into the battery, thus avoiding problems.

[0069] Conventionally, performing laser welding inside a housing requires configuring the optical system of the laser welding apparatus so that the laser beam does not deviate from the hole formed at the winding center. This necessitates reliable laser focusing over a long distance, such as the length of the hole at the winding center, and the laser beam must pass through the hole at the winding center, making it difficult to prevent damage to the surrounding electrode assembly during the welding process. In the present invention, welding is performed outside the housing 20, eliminating the need to modify or upgrade the optical system of the laser welding apparatus. Since the laser beam does not pass around the electrode assembly 10, there is no damage to the electrode assembly 10. Therefore, laser welding, which offers superior welding strength, can be conveniently used to connect the current collector 30, terminal 40, and terminal block 50, making it desirable. In the present invention, applying laser welding prevents deformation caused by contact pressure welding such as resistance welding, which is advantageous not only for ensuring quality and performance but also for improving product yield. Laser welding eliminates the need to change welding rods or horns, which is advantageous for improving production efficiency and reducing production costs, and shortens manufacturing process time. Furthermore, laser welding offers higher joint strength compared to ultrasonic welding and ensures uniformity of welding performance and quality compared to resistance welding.

[0070] In another aspect of the present invention, the surface to which the current collector 30, terminal block 50, and terminal 40 are joined (SA in Figure 4) can form a flat surface parallel to the closed portion of the housing 20. The surface to which the current collector 30, terminal block 50, and terminal 40 are joined can function as the positive terminal of the battery. Therefore, it is desirable that the joining surface be flat. For example, if the current collector 30, terminal 40, and terminal block 50 are welded outside the housing 20, a weld bead W is formed. In this case, since the weld bead W is formed by the melting and solidification of the metal, it may not have a uniform flat shape. Therefore, in some cases, it may be necessary to flatten the joining surface of the current collector 30, terminal block 50, and terminal 40 after welding them together. In conclusion, the surface to which the current collector 30, terminal block 50, and terminal 40 are joined can form a flat surface parallel to the closed portion of the housing 20. Here, "parallel" means that they are substantially parallel when observed visually. "Flat" means that they are level.

[0071] In yet another embodiment of the present invention, referring to Figure 5, the plain section coupling portion 32 and the terminal coupling portion 33 are not directly connected, but are arranged to be spaced apart from each other and electrically connected by the edge portion 31. Thus, the current collector 30 according to one embodiment of the present invention has a structure in which the plain section coupling portion 32 and the terminal coupling portion 33 are not directly connected to each other but are connected via the edge portion 31, which allows for the dispersion of impact applied to the coupling portion between the plain section coupling portion 32 and the first plain section 11, and the coupling portion between the terminal coupling portion 33 and the terminal 40, when impact and / or vibration occurs in the cylindrical battery cell 1. Therefore, the current collector 30 of the present invention can minimize or prevent damage to the welded portion due to external impact. The current collector 30 of the present invention has a structure in which stress can concentrate at the connection portion between the edge portion 31 and the terminal coupling portion 33 when an external impact is transmitted to the inside of the battery cell 1 via the terminal 40. However, such a connection portion is not a portion where a welded portion is formed for joining parts. Therefore, in the present invention, it is possible to effectively prevent product defects caused by damage to the welded joint due to external impact.

[0072] In yet another embodiment of the present invention, referring to Figure 6, the current collector 30 may further include a connecting portion 34 extending inward from the edge portion 31 and connecting to the terminal coupling portion 33. In the current collector 30, the plain portion coupling portion 32 and the terminal coupling portion 33 are not directly connected to each other but may be indirectly connected by the connecting portion 34. The extending direction of the plain portion coupling portion 32 and the extending direction of the connecting portion 34 may not be parallel. The connecting portion 34 may extend substantially radially from the approximate center of the terminal coupling portion 33 and connect to the edge portion 31.

[0073] The connecting portion 34 may have a tapered portion 34a whose width narrows along the direction from the inner surface of the edge portion 31 toward the terminal connecting portion 33. When a tapered portion 34a is provided, the rigidity of the component at the connection point between the connecting portion 34 and the edge portion 31 can be improved.

[0074] Referring to Figure 6, multiple connection points 34 may be provided. The number of connection points 34 can be determined by considering the required resistance level for the cylindrical battery cell 1, the aperture ratio of the current collector 30, and so on. Each of the multiple connection points 34 may be positioned between a pair of adjacent plain section connection points 32. The multiple connection points 34 may be arranged regularly with respect to each other along the extending direction of the edge portion 31. For example, the multiple connection points 34 may be arranged at substantially the same interval along the extending direction of the edge portion 31. The number of connection points 34 may be, for example, one or two. This is to quickly interrupt overcurrent. If the number of connection points 34 is excessively large, the current flow may be dispersed, and the fusing function may not operate properly. Considering the rigidity of the current collector 30, the number of connection points 34 may be two.

[0075] In one embodiment of the present invention, the terminal coupling portion 33 may include a first part 331 and a second part 332.

[0076] More specifically, referring to Figures 5 and 6, the terminal coupling portion 33 may include a first part 331 extending parallel to the closing portion and a second part 332 extending perpendicularly from the first part 331 toward the outside of the housing 20.

[0077] If the current collector 30 has a substantially flat plate shape, the first part 331 may correspond to a part that constitutes the plate shape. That is, the first part 331 may be configured to have a plate shape parallel to the closing portion.

[0078] On the other hand, the second part 332 may be configured to be perpendicular to the first part 331. For example, the second part 332 may have a structure that extends upward from the first part 331. That is, the second part 332 may extend in a direction parallel to the winding axis direction of the electrode assembly 10. More specifically, the second part 332 may have a substantially pipe shape that extends upward from the first part 331. That is, the second part 332 may be configured to have a hollow pipe shape. In other words, the second part 332 may be configured to be a substantially cylindrical shape with a hollow interior. However, the shape of the second part 332 is not limited to this, and any shape that is hollow and extends in the winding axis direction is included in the scope of the present invention.

[0079] Referring again to Figures 5 and 6, the empty space inside the second part 332 can be configured to accommodate the aforementioned terminal block 50. On the other hand, the outer surface of the second part 332 can be coupled to the aforementioned terminal 40. More specifically, the second part 332 can be configured to accommodate the empty space inside the terminal connection portion 43 of the terminal 40, which will be described later. As a result, the current collector 30 can be inserted into the terminal 40, and the terminal block 50 can be inserted into the current collector 30. Alternatively, the current collector 30 can be inserted from below to above the terminal 40, and the terminal block 50 can be inserted from above to below the current collector 30. The terminal 40 is first assembled to the closing surface of the housing 20, the current collector 30 is inserted inside the housing 20 and assembled with the terminal 40, and the terminal block 50 is inserted into the current collector 30 from the outside of the housing 20.

[0080] With this structure, since the current collector 30, terminal 40, and terminal block 50 are welded outside the housing 20, even if spatter is generated during welding, the spatter does not flow into the inside of the battery, preventing damage to the separator membrane. Furthermore, the problem of reduced battery capacity and lifespan can be solved. Moreover, with the above-described structure of the present invention, since the current collector 30, terminal 40, and terminal block 50 are welded outside the housing 20, it is not necessary to insert the welding horn tip inside the electrode assembly 10, and the diameter of the hole formed in the winding center C of the electrode assembly 10 can be reduced. As a result, the energy density can be improved by increasing the number of windings of the electrode assembly 10.

[0081] On the other hand, referring to Figure 3, the first part 331 is provided with an injection hole H that is concentric with the second part 332 and has the same diameter as the inner diameter of the second part 332. The manufacturing method of the battery cell 1 using such a current collector 30 is as follows.

[0082] Terminals 40 are machined into the closed portion of the housing 20. The blank coupling portion 32 of the current collector 30 is coupled to the first blank portion 11 of the electrode assembly 10. Other current collectors are coupled to the second blank portion 12 of the electrode assembly 10. For coupling, welding methods such as laser welding, resistance welding, or ultrasonic welding can be used. The electrode assembly 10 is pushed into the housing 20 through the open portion of the housing 20, and the terminals 40 and current collectors 30 are assembled. The open portion of the housing 20 is finished by beading and crimping, so that it looks like the lower end of the battery cell 1 in Figures 1 and 2. Then, electrolyte is injected through the injection hole H. The terminal block 50 is inserted inside the terminal coupling portion 33 to close the injection hole H. Then, the current collectors 30, terminals 40, and terminal block 50 are welded to the outside of the housing 20.

[0083] In this way, by configuring the current collector 30 and the terminal block 50 separately, the electrolyte can be injected through the injection hole H formed in the current collector 30, then covered with the terminal block 50, and welding can be performed outside the housing 20.

[0084] Figure 7 is a diagram illustrating a current collector according to another embodiment of the present invention. To show the internal structure of the terminal coupling portion 33, the terminal coupling portion 33 is shown in cross-section.

[0085] Referring to Figure 7, the first part 331 is provided with an injection hole H that is concentric with the second part 332 and has a smaller diameter than the inner diameter of the second part 332. In other words, the first part 331 extends further into the interior of the second part 332 from its inner wall. This allows the terminal block 50 to be placed and supported on the extended and protruding portion of the first part 331. Therefore, the current collector 30 in Figure 7 corresponds to a support portion 331a formed at the bottom of the second part 332 for securing the lower surface of the terminal block 50.

[0086] When the terminal block 50 is coupled to the inside of the current collector 30, the lower surface of the terminal block 50 can be securely attached to the support portion 331a. Therefore, when the terminal block 50 is inserted into the empty space of the terminal coupling portion 33, it can be fixed in a certain position in the space below the support portion 331a, in other words, without moving any further downward.

[0087] Figure 8 is a diagram illustrating a terminal according to one embodiment of the present invention.

[0088] Referring to Figure 8, the terminal 40 includes a terminal exposure portion 41, a terminal insertion portion 42, and a terminal connection portion 43.

[0089] The exposed terminal portion 41 is exposed to the outside of the housing 20. The exposed terminal portion 41 may be located approximately in the center of the closed portion of the housing 20. That is, the terminal 40 can pass through approximately in the center of the closed portion. The exposed terminal portion 41 may have a shape that extends approximately parallel to the closed portion.

[0090] The terminal insertion portion 42 may have a curved shape toward the inner surface of the closing portion of the housing 20. Therefore, the maximum width of the terminal insertion portion 42 after the riveting process for fixing the terminal 40 may be made larger than the maximum width of the hole formed in the housing 20 for the terminal insertion portion 42 to pass through. The terminal insertion portion 42 may have a shape that extends substantially parallel to the closing portion. That is, the terminal insertion portion 42 may have a shape that extends substantially parallel to the terminal exposure portion 41. Of course, the shape of the terminal insertion portion 42 is not limited thereto.

[0091] Referring to Figures 3 and 4, the terminal connection portion 43 can connect the terminal exposure portion 41 and the terminal insertion portion 42. The terminal connection portion 43 can penetrate the housing 20. Specifically, the terminal connection portion 43 can penetrate the closing portion of the housing 20. More specifically, the terminal connection portion 43 can penetrate approximately the center of the closing portion of the housing 20. The terminal connection portion 43 may extend in a direction approximately parallel to the winding axis of the electrode assembly 10. The terminal exposure portion 41 may be located at one end of the terminal connection portion 43. The terminal exposure portion 41 may be configured to extend horizontally from one end of the terminal connection portion 43. The terminal insertion portion 42 may be located at the other end of the terminal connection portion 43. The terminal insertion portion 42 may be configured to extend horizontally from the other end of the terminal connection portion 43.

[0092] The terminal connection portion 43 may have a substantially pipe shape extending in a direction parallel to the winding axis of the electrode assembly 10. That is, the terminal connection portion 43 may be configured to have a hollow pipe shape. In other words, the terminal connection portion 43 may be configured to have a substantially cylindrical shape with a hollow interior. However, the shape of the terminal connection portion 43 is not limited to this, and any shape that is hollow and extends in the direction of the winding axis is included within the scope of the present invention.

[0093] Referring again to Figure 8 in conjunction with Figures 3 and 4, the second part 332 of the current collector 30 can be inserted into the empty space inside the terminal connection portion 43. That is, the terminal connection portion 43 can be coupled to the terminal coupling portion 33 of the current collector 30. The outer diameter of the second part 332 may be smaller than or the same as the inner diameter of the terminal connection portion 43. In other words, it is desirable that the outer diameter of the second part 332 be smaller than or the same as the inner diameter of the terminal connection portion 43 in order to insert the second part 332 of the current collector 30 into the empty space inside the terminal connection portion 43.

[0094] Referring again to Figures 3 and 4 in one embodiment of the present invention, the insulating gasket G2 includes an exposed gasket portion and a inserted gasket portion. The insulating gasket G2 may be provided on the closed side of the housing 20. The exposed gasket portion is interposed between the exposed terminal portion 41 of the terminal 40 and the housing 20. The exposed gasket portion extends longer than the exposed terminal portion 41, thereby allowing it to be exposed to the outside of the exposed terminal portion 41 when the cylindrical battery cell 1 is viewed from above. The inserted gasket portion is interposed between the inserted terminal portion 42 of the terminal 40 and the housing 20. The inserted gasket portion is deformed together with the inserted terminal portion 42 during riveting, and can adhere closely to the inner surface of the closed portion of the housing 20. The insulating gasket G2 may be made of, for example, a resin material having insulating and elastic properties.

[0095] Referring again to Figures 3 and 4, the insulator 60 may be provided between the current collector 30 and the inner surface of the housing 20. The insulator 60 prevents contact between the current collector 30 and the housing 20. The insulator 60 may also be interposed between the upper end of the outer circumferential surface of the electrode assembly 10 and the inner surface of the housing 20. That is, the insulator 60 may also be interposed between the first plain portion 11 and the inner surface of the side wall portion of the housing 20. This is to prevent contact between the first plain portion 11, which extends toward the closing portion of the housing 20, and the inner circumferential surface of the housing 20.

[0096] Figure 9 is a diagram illustrating a terminal block according to one embodiment of the present invention. Figure 10 is an enlarged cross-sectional view of the upper part of the battery cell in Figure 1, and Figure 11 is an enlarged view of a part of Figure 10. Figure 12 is a diagram illustrating the area to which welding is applied in a battery cell according to one embodiment of the present invention. Figure 13 is a diagram illustrating the area to which welding is applied in a battery cell according to another embodiment of the present invention. Figure 14 is a top view of a battery cell showing a state in which welding has been performed in the battery cell according to another embodiment of the present invention.

[0097] Referring to Figures 9 to 11, the terminal block 50 may be configured to have a substantially disc shape or a cylindrical shape. For example, referring to Figure 10, the terminal block 50 may be configured to be cylindrical with a predetermined diameter K. As mentioned above, the terminal block 50 can be coupled to the inner space of the current collector 30. More specifically, the terminal block 50 can be coupled to the inner space of the terminal coupling portion 33 of the current collector 30. More specifically, the terminal block 50 can be coupled to the inner space of the second part 332 of the current collector 30. The outer shape of the terminal block 50 may be configured to match the inner shape of the second part 332 of the current collector 30. This eliminates any gap between the terminal block 50 and the current collector 30. The empty space inside the second part 332 and the fluid injection hole H of the first part 331 can be considered to form an opening on one side of the battery cell 1. With such a configuration, the terminal block 50 can effectively close the opening formed on one side of the battery cell 1.

[0098] In one embodiment of the present invention, referring to Figure 10, the diameter D of the hole formed in the winding center C of the electrode assembly 10 can be smaller than a predetermined size. For example, in the structure of conventional battery cells, it was necessary to insert a welding horn tip into a hole formed in the winding center of the electrode assembly to weld the current collector and the terminal. In this case, it was difficult to reduce the diameter of the welding horn tip, so conventionally it was necessary to ensure a certain diameter for the hole formed in the winding center of the electrode assembly, which limited the increase in energy density. However, according to the structure of the present invention described above, since the current collector 30, terminal 40, and terminal block 50 are welded outside the housing 20, it is no longer necessary to insert a welding horn tip into a hole formed in the winding center C of the electrode assembly, and the diameter D of the hole formed in the winding center C of the electrode assembly can be reduced. As a result, the energy density can be improved by increasing the number of turns of the electrode assembly 10.

[0099] Referring to Figure 12, the current collector 30 and the terminal 40, and / or the current collector 30 and the terminal block 50, can be joined by welding. That is, the joining of the current collector 30 and the terminal 40, and / or the current collector 30 and the terminal block 50 can be done by welding. For example, laser welding, ultrasonic welding, etc., can be applied to the present invention.

[0100] Referring to Figure 12, welding can be applied at the point between the current collector 30 and the terminal 40. This allows a weld bead W to be formed between the current collector 30 and the terminal 40. Alternatively, welding can be applied between the current collector 30 and the terminal block 50. This allows a weld bead W to be formed between the current collector 30 and the terminal block 50.

[0101] Thus, the current collector 30, terminal 40, and terminal block 50 are joined by welding, and since the current collector 30, terminal 40, and terminal block 50 all contain metal, the current collector 30, terminal 40, and terminal block 50 can have the same polarity as each other. For example, the current collector 30, terminal 40, and terminal block 50 can have the same polarity as the first electrode. As a result, the joint surface where the current collector 30, terminal 40, and terminal block 50 are joined (see SA in Figure 4) can function as the first electrode terminal.

[0102] As another embodiment, referring to Figures 13 and 14, welding can be applied to the entire area including the current collector 30, terminal 40, and terminal block 50.

[0103] For example, welding can be performed twice: once between the terminal 40 and the current collector 30, and once between the current collector 30 and the terminal block 50, but it can also be done simultaneously. This allows a weld bead W to be formed over the entire area including the current collector 30, the terminal 40, and the terminal block 50.

[0104] In particular, according to this embodiment, a weld bead W is formed along the second part 332 on the joint surface SA where the current collector 30, terminal 40, and terminal block 50 are joined, clearly indicating that welding is performed outside the housing 20. The weld bead W is formed by laser welding. The weld bead W refers to the weld metal formed by a single welding pass (a single laser beam pass), and is also called a weld spot. The size, shape, position, and overlap of the weld bead W can vary depending on the welding conditions. Laser beam welding methods include wobble welding, spot welding, weaving (hatching) welding, and scan welding, and Figure 14 shows a wobble welding bead W.

[0105] Figure 15 is a diagram illustrating a terminal block according to another embodiment of the present invention. Figure 16 shows the terminal block of Figure 15 inserted into the second part of the current collector of Figure 7.

[0106] Referring to Figures 15 and 16, the terminal block 50 is cylindrical, and the outer circumference of the upper part is chamfered to form a tapered surface 50a. The lower surface of the terminal block 50 can be fixed to the support portion 331a of the current collector 30.

[0107] When a terminal block 50 having such a structure is inserted into the inner space of the second part 332, the upper outer circumference of the terminal block 50 is a tapered surface 50a, which has a separation distance G between it and the inner surface of the second part 332, while the lower part is in contact with the inner surface of the second part 332. The separation distance G is largest at the upper surface of the terminal block 50 and decreases towards the bottom. In this state, when a laser beam is irradiated onto the boundary between the terminal block 50 and the second part 332, the generated heat melts the terminal block 50 and the second part 332 located at the boundary, forming a weld bead W. The heat remaining at the boundary is transmitted deep into the boundary, that is, to the lower part in the longitudinal direction of the second part 332, increasing the depth of the weld bead W and increasing the area over which the terminal block 50 and the second part 332 are welded, thus strengthening the bond. In addition, it is possible to prevent the weld bead W from protruding onto the joint surface SA where the current collector 30, terminal 40, and terminal block 50 are joined. Since the joint surface SA where the current collector 30, terminal 40, and terminal block 50 are joined can be kept flat without irregularities, this has the effect of enabling good welding of the busbars during the module manufacturing process.

[0108] Figure 17 is a diagram illustrating the battery pack containing the battery cells shown in Figure 1.

[0109] Referring to Figure 17, the battery pack 3 according to the present invention may include at least one of the battery cells 1 according to the present invention described above. The battery pack 3 according to the present invention may also include a pack housing 2 capable of housing at least one battery cell 1. Furthermore, in addition to such battery cell 1, it may further include various other components, such as a BMS, pack case, relay, current sensor, and other components of a battery pack 3 known at the time of filing of the present invention.

[0110] The battery pack 3 can contain multiple battery cells 1. The battery cells 1 are arranged in a predetermined number of rows, with each battery cell 1 having terminal 40 used as the first electrode terminal and the remaining area of ​​the housing 20 used as the second electrode terminal. Therefore, when electrically connecting multiple battery cells 1, both the positive and negative electrodes can be connected in one direction, simplifying the electrical connection structure. This increases the number of battery cells 1 that can be mounted in the same space, thereby improving energy density and facilitating electrical wiring work. Consequently, the excellent space efficiency and high efficiency of electrical wiring result in significant improvements in work efficiency during the assembly process of electric vehicles, and during the assembly and maintenance of the battery pack 3.

[0111] Figure 18 is a diagram illustrating the automobile including the battery pack shown in Figure 17.

[0112] Referring to Figure 18, the automobile 5 according to the present invention may include at least one battery pack 3 according to the present invention.

[0113] The battery cell according to the present invention can be applied to automobiles such as electric vehicles and hybrid vehicles. That is, the automobile 5 according to the present invention may include the battery cell 1 or the battery pack 3 according to the present invention. In addition, the automobile 5 according to the present invention may further include various other components included in the automobile, in addition to the battery cell 1 or battery pack 3. For example, the automobile 5 according to the present invention may further include the vehicle body, motor, control device such as an ECU (electronic control unit), in addition to the battery cell 1 according to the present invention. The automobile 5 includes four-wheeled automobiles and two-wheeled automobiles. The automobile 5 can operate by receiving power from the battery pack 3 according to one embodiment of the present invention.

[0114] On the other hand, while terms indicating directions such as up and down are used in this specification, these terms are for convenience of explanation and it will be obvious to those skilled in the art that they can change depending on the position of the object in question, the position of the observer, etc.

[0115] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that any person with ordinary skill in the art to which the present invention belongs can make various modifications and variations within the equivalent scope of the technical idea of ​​the present invention and the following claims. [Explanation of Symbols]

[0116] 5: Automobile 3: Battery pack 2: Pack Housing 1: Battery cell 10: Electrode Assembly 11: First blank section 12: Second blank section C: Winding center 20: Housing 20a: Outer surface 30: Current collector 31: Edge 32: Plain section joining part 33: Terminal connection part 331: Part 1 332: Part 2 34: Connection part 34a: Tapered section 40: Terminals 41:Exposed terminal part 42: Terminal insertion section 43: Terminal connection section 50: Terminal Block G2: Insulating gasket 60: Insulator

Claims

1. An electrode assembly comprising a first electrode, a second electrode, and a separation membrane interposed between them, which are wound around a winding axis to define a core and an outer surface, wherein the first electrode includes a first plain portion along the winding direction where the active material layer is not coated, and the electrode assembly comprises A housing having an opening on one side and configured to house the electrode assembly through the opening, A current collector including an edge portion positioned on the upper part of the electrode assembly, a blank portion connecting portion extending inward from the edge portion and connecting to the first blank portion, and a terminal connecting portion located in the center away from the blank portion connecting portion and exposed to the outside of the housing, A terminal that penetrates the closed portion of the housing located on the opposite side of the open portion, is exposed to the outside of the housing, and is connected to the terminal coupling portion, A terminal block configured to be coupled to the inside of the current collector, Battery cells, including

2. The battery cell according to claim 1, wherein the current collector, the terminal, and the terminal block are configured to be welded together outside the housing.

3. The battery cell according to claim 2, wherein the coupling surface where the current collector, the terminal, and the terminal block are coupled constitutes a flat portion parallel to the closing portion of the housing.

4. The aforementioned terminal coupling portion is A first part extending parallel to the closing portion, A second part extending perpendicularly from the first part toward the outside of the housing, A battery cell according to claim 1, including the battery cell described in claim 1.

5. The battery cell according to claim 4, wherein the second part extends in a direction parallel to the winding axis of the electrode assembly.

6. The battery cell according to claim 4, wherein the second part is configured to have a hollow pipe shape inside.

7. The battery cell according to claim 6, wherein the first part is provided with an injection hole that is concentric with the second part and has a diameter less than or equal to the inner diameter of the second part.

8. The battery cell according to claim 6, wherein a support portion is formed at the bottom of the second part for securing the lower surface of the terminal block.

9. The battery cell according to claim 4, wherein the outer diameter of the terminal block is the same as the inner diameter of the second part.

10. The battery cell according to claim 4, wherein the terminal block is cylindrical and the outer circumference of the upper part is chamfered to form a tapered surface.

11. The battery cell according to claim 4, wherein a weld bead is formed along the second part on the joint surface where the current collector, the terminal, and the terminal block are joined.

12. The battery cell according to claim 1, wherein the terminal penetrates the center of the closed portion.

13. The aforementioned terminal is, The terminal exposed portion that is exposed to the outside of the housing, A terminal insertion portion located inside the housing, which penetrates the closing portion of the housing, A terminal connection portion that connects the terminal exposure portion and the terminal insertion portion and penetrates the housing, The battery cell according to claim 4, including the battery cell described in claim 4.

14. The battery cell according to claim 13, wherein the terminal connection portion is configured to have a hollow pipe shape inside.

15. The battery cell according to claim 13, wherein the outer diameter of the second part is smaller than or equal to the inner diameter of the terminal connection portion.

16. The battery cell according to claim 13, wherein an insulating gasket is provided on the closed portion side of the housing, interposed between the housing and the terminal.

17. The aforementioned insulating gasket is The gasket exposed portion interposed between the terminal exposed portion and the housing, A gasket insertion portion interposed between the terminal insertion portion and the housing, The battery cell according to claim 16, including the battery cell described in claim 16.

18. A battery pack comprising at least one battery cell as described in any one of claims 1 to 17.

19. An automobile comprising at least one battery pack as described in claim 18.

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