Electrode connection, cylindrical battery cell, battery pack and vehicle

Abstract

Cylindrical battery cell (70), comprising: an electrode arrangement (71) comprising a first electrode plate, a second electrode plate and a separator arranged between them, wherein the electrode arrangement (71) is wound such that it has a first end face and a second end face (52) opposite each other, wherein the first electrode plate has an uncoated section arranged at the first end face of the electrode arrangement (71) and the second electrode plate has an uncoated section arranged at the second end face (52) of the electrode arrangement (71), wherein the uncoated sections extend beyond the separator; a battery box (51) which accommodates the electrode arrangement (71) and is electrically connected to the first electrode plate, wherein the battery box (51) has a first end face and a second end face (52) which are opposite each other, wherein the first end face is open; an electrode connection (50, 50') which passes through a perforated opening (53) formed in the second end face (52) of the battery box (51); and a sealing body (74) that closes the first end face of the battery box (51); a seal (54) which is arranged between the electrode connection (50, 50') and the perforation opening (53), where the electrode connection has (50, 50'): - a body segment (50a) that passes through the perforation opening (53); - an outer flange section (50b) extending from the body section (50a) along an outer surface (52a) of the second end surface (52) of the battery box (51); - an inner flange section (50c) arranged inside the battery box (51) and extending outwards from the body section (50a); and - a flat section (50d) arranged in the battery box (51) and surrounded by the inner flange section (50c), wherein a recess is formed between the inner flange section (50c) and the flat section (50d); wherein the seal (54) has: an outer seal (54a) arranged between the outer flange section (50b) and the outer surface (52a) of the second end surface (52) of the battery box (51); and an inner seal (54b) arranged between the inner flange section (50c) and the inner surface (52b) of the second end surface (52) of the battery box (51), wherein at least one section (54a') of the outer seal (54a) is exposed to the outside of the outer flange section (50b) of the electrode connection (50), wherein the exposure width (G) of the outer seal (54a), measured in a direction parallel to the outer surface of the second end surface (52) of the battery box (51), is 0.1 mm to 1 mm.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an electrode connection and a cylindrical battery cell, a battery pack and a vehicle comprising the same. STATE OF THE ART

[0002] Secondary batteries, which are easily adaptable for different product groups and have electrical properties such as high energy density, are universally used, not only for portable devices but also for electric vehicles (EVs), hybrid electric vehicles (HEVs) or the like, which are powered by an electric drive source.

[0003] These secondary batteries are attracting attention as a new energy source for improving environmental friendliness and energy efficiency, as they have the primary advantage of being able to drastically reduce the use of fossil fuels, as well as the secondary advantage that no by-products are generated from energy use.

[0004] Secondary batteries, which are currently widely used in technology, include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. A secondary battery cell has an operating voltage of approximately 2.5 V to 4.5 V. Therefore, if a higher output voltage is required, a battery pack is configured by connecting a large number of battery cells in series. Additionally, a large number of battery cells can be connected in parallel to form a battery pack according to the required charge / discharge capacity. Accordingly, the number of battery cells contained in the battery pack and the form of the electrical connection can be adjusted according to the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, cylindrical, rectangular, and pouch-shaped battery cells are known types of secondary battery cells. In the case of a cylindrical battery cell, a separator, which acts as an insulator, is positioned between a positive and a negative electrode. These electrodes are wound to form an electrode assembly in the form of a jelly-roll structure, which, along with an electrolyte, is inserted into a battery can to configure the battery. Additionally, a strip-shaped electrode tab may be connected to an uncoated section of each of the positive and negative electrodes. This electrode tab electrically connects the electrode assembly to an electrode terminal that is exposed externally. For example, the positive electrode terminal is a cover plate of a sealing body that seals the opening of the battery can, and the negative electrode terminal is the battery can itself.

[0006] However, according to the conventional cylindrical battery cell with such a structure, the current collection efficiency is not good due to high resistance and high heat generation due to a small cross-sectional area of ​​the strip-shaped electrode tab, as current is concentrated in the strip-shaped electrode tab that is coupled to the uncoated section of the positive electrode and / or the uncoated section of the negative electrode.

[0007] For small cylindrical battery cells with a form factor of 18650 or 21700, resistance and heat are not a major problem. However, when the form factor is increased to fit the cylindrical battery cell into an electric vehicle, the cylindrical battery cell can ignite if a lot of heat is generated around the electrode tab during the fast-charging process.

[0008] To solve this problem, a cylindrical battery cell (so-called tabless cylindrical battery cell) is provided in which the uncoated section of the positive electrode and the uncoated section of the negative electrode are designed to be positioned on the top and bottom of the jelly roll type electrode assembly, respectively, and the current collector plate is welded to the uncoated section to improve current collection efficiency. DESCRIPTION

[0009] The Fig. Figures 1 to 3 schematically show a manufacturing process for a tabless cylindrical battery cell. Fig. Figure 1 shows the structure of an electrode plate, Fig. Figure 2 shows a winding process of the electrode plate and Fig. Figure 3 shows a welding process of a current collector plate to a curved surface of an uncoated section. Fig. Figure 4 shows a sectional view of the tabless cylindrical battery cell along a longitudinal direction (Y).

[0010] With reference to the Fig. 1 to 4 have a positive electrode plate 10 and a negative electrode plate 11, a structure in which a plate-shaped current collector 20 is coated with an active mass 21, and comprise an uncoated section 22 on a longitudinal side along the winding direction X.

[0011] An electrode assembly A is produced by stacking the positive electrode plate 10 and the negative electrode plate 11 one after the other together with two separating plates 12, as shown in Fig. 2 shown, and they are then wound in direction X. At this point, the uncoated sections of the positive electrode plate 10 and the negative electrode plate 11 are arranged in opposite directions.

[0012] After the winding process, the uncoated section 10a of the positive electrode plate 10 and the uncoated section 11a of the negative electrode plate 11 are bent towards the core. Then, current collector plates 30 and 31 are welded and coupled to the uncoated sections 10a and 11a, respectively.

[0013] An electrode tab is not separately coupled to the uncoated section 10a of the positive electrode and the uncoated section 11a of the negative electrode; the current collector plates 30, 31 are connected to external electrode terminals; and a current path with a large cross-sectional area is formed along the winding axis direction of the electrode assembly A (see an arrow in Fig. 3) which has the advantage of reducing the resistance of the battery cell. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0014] However, if the form factor of the cylindrical battery cell increases and the size of the charging current during fast charging increases, the heat problem also occurs again in the tabless cylindrical battery cell.

[0015] In particular, the conventional tabless cylindrical battery cell 40 has a battery housing 41 and a sealing body 42, as shown in Fig. Figure 4 shows the sealing body 42 comprising a cover plate 42a, a seal 42b, and a connecting plate 42c. The seal 42b surrounds the edge of the cover plate 42a and is secured by a crimp section 43. Additionally, the electrode assembly A is secured in the battery box 41 by a beaded section 44 to prevent vertical movement.

[0016] Typically, the positive electrode terminal is the cover plate 42a of the sealing body 42, and the negative electrode terminal is the battery box 41. Accordingly, the current collector plate 30, which is coupled to the uncoated section 10a of the positive electrode plate 10, is electrically connected to the connecting plate 42c, which is attached to the cover plate 42a, by a strip conductor 45. Additionally, the current collector plate 31, which is coupled to the uncoated section 11a of the negative electrode plate 11, is electrically connected to the underside of the battery box 41. An insulator 46 covers the current collector plate 30 to prevent the battery box 41 and the uncoated section 10a of the positive electrode plate 10, which have opposite polarities, from touching each other and causing a short circuit.

[0017] When the current collector plate 30 is connected to the connection plate 42c, the conductor 45 is used in the form of a strip. The conductor 45 is either attached separately to the current collector plate 30 or manufactured integrally with it. However, because the conductor 45 is in the form of a thin strip, its cross-sectional area is small, and thus a significant amount of heat is generated when the fast-charging current flows. Additionally, the excessive heat generated by the conductor 45 is transferred to the electrode assembly A, causing the separator 12 to shrink, which can lead to an internal short circuit, a major cause of thermal runaway.

[0018] The conductor 45 also occupies a considerable amount of space within the battery box 41. Therefore, the cylindrical battery cell 40, including the conductor 45, has low space efficiency, thus limiting the potential increase in energy density.

[0019] Furthermore, connecting the conventional tabless cylindrical battery cells 40 in series and / or parallel requires connecting a busbar component to the cover plate 42a of the sealing body 42 and the base of the battery box 41, which reduces space efficiency. A battery pack mounted on an electric vehicle comprises hundreds of cylindrical battery cells 40. Therefore, the inefficiency of the electrical wiring causes significant inconvenience during the electric vehicle assembly process and battery pack maintenance. TECHNICAL TASK

[0020] The present disclosure is designed to solve the problems of the prior art, and therefore the present disclosure is directed to reduce the internal resistance of a cylindrical battery cell and increase the energy density by improving an electrode connection structure of the cylindrical battery cell in order to increase the space efficiency in a battery can.

[0021] The present disclosure is also aimed at improving the electrode connection structure of a cylindrical battery cell in order to solve the internal heating problem caused during fast charging by increasing the cross-sectional area of ​​a current path.

[0022] The present disclosure is also directed to provide a cylindrical battery cell with an improved structure that allows the electrical wiring for the series and / or parallel connection of the cylindrical battery cells to be carried out on one side of the cylindrical battery cells.

[0023] The present disclosure is also directed to provide a battery pack manufactured using the cylindrical battery cell with an improved structure and a vehicle comprising the battery pack.

[0024] However, the technical problems to be solved by the present disclosure are not limited to those above, and other problems not mentioned here will be clear to those skilled in the art from the following disclosure. TECHNICAL SOLUTION

[0025] The present invention is defined by the subject matter of the independent claims. Specific examples of the present invention are defined by the features of the dependent claims. Furthermore, each of the features described above may also be included in the claimed subject matter, provided this is not unreasonable.

[0026] A structure may be provided. The structure may refer to a product, system, device, or apparatus that provides a passage (or conduit passage, which may be figuratively described as a riveted structure) for an electrode to pass from inside a housing to the outside. Such a passage may be electrically conductive and may be referred to as a terminal (or electrode terminal).

[0027] The structure may include a battery box, an electrode terminal, and a seal. The battery box may have a first end face and a second end face that are opposite each other. Generally, each of the first and second end faces may be open, closed, or closed except for an opening. The first end face of the battery box may be open. The second end face may be closed except for an opening. Here, a closed section of the second end face may be referred to as the bottom (of the battery box). The (closed) second end face of the battery box may have an inner surface or inside, located within the battery box. The (closed) second end face of the battery box may have an outer surface or outside, located outside the battery box.

[0028] The electrode connection can pass through a perforation formed in the second end face of the battery can. The gasket can be positioned between the electrode connection and the perforation. The electrode connection can have a body section, an outer flange section, an inner flange section, and a flat section. The body section of the electrode connection can pass through the perforation. The outer flange section of the electrode connection can extend from the body section along an outer surface of the second end face of the battery can. The inner flange section of the electrode connection can be located inside the battery can and extend outward from the body section. The flat section of the electrode connection can be located inside the battery can and surrounded by the inner flange section.

[0029] The battery canister can have a cylindrical geometry. The cylindrical geometry of the battery canister can define a radial direction, an axial (extensional) direction, and a circumferential (tangential) direction according to the principles of basic mathematics. Hereinafter, and unless otherwise specified, a view in the axial direction can be understood as a top view. The first end face and the second end face of the battery canister can each extend in the radial and circumferential directions (and / or perpendicular to the axial direction) of the battery canister. The battery canister can have a side wall extending between the first end face and the second end face. The first end face of the battery canister can be substantially open (i.e., hollow, empty). For example, the first end face of the battery canister can be open except for a circumference (an edge segment).For example, the first end face of the battery box may be open to allow an electrode assembly to be inserted through it.

[0030] The perforation formed in the second end face of the battery canister can be a through-hole. The perforation can be designed to allow the electrode connector or the body portion of the electrode connector to pass through it. The second end face of the battery canister can be solid (closed) except for the perforation.

[0031] The side wall can be referred to as an outer circumferential surface or side surface of the battery box. The side wall of the battery box can be entirely or at least substantially solid. The battery box or its components can have any of the respective features described below with reference to the drawings.

[0032] The electrode terminal can also be referred to as a connection. The electrode terminal may penetrate the second end face of the battery can or, figuratively speaking, be riveted through it (the perforation opening). The electrode terminal may provide a passage for an electrode, which may be contained within the battery can, to the outside of the battery can. Alternatively or additionally, the electrode terminal may provide a contact surface configured to connect to an external load. The electrode terminal may have a (substantially or approximately) cylindrically symmetrical shape. Accordingly, the electrode terminal may have an axial direction, a radial direction, and a circumferential (tangential) direction. The electrode terminal may be arranged such that the axis of symmetry of the cylindrical geometry coincides with the axis of symmetry of the battery can.Alternatively or additionally, the electrode connection can have a shape that is rotationally symmetric, mirror-symmetric, or any other symmetrical shape with respect to the axis of symmetry. The electrode connection can have any of the respective features of an electrode connection described below with reference to the drawings.

[0033] The electrode connection can extend through the perforated opening formed in the second end face of the battery box. The body section can refer to a central part of the electrode connection with respect to the radial direction (particularly of the battery box or the electrode connection) of the structure. The body section can refer to a portion of the electrode connection that extends through the perforated opening into / from the second end face of the battery box. The body section can project outward from the battery box. The body section can extend into the battery box. The body section can have a block shape or a cylindrical shape. The body section can have a cross-section (e.g., a circular cross-section) that, in plan view (in shape and size), corresponds to a cross-section of the perforated opening.The body section can have any of the respective features of a body section, which are described below with reference to the drawings.

[0034] The outer flange section may refer to a portion of the electrode connection that is located, or designed to be located, outside the battery housing. The outer flange section may refer to a portion of the electrode connection that extends radially outward from the body section outside the battery housing. The outer flange section may approximately have the shape of a washer (washer, lining washer). In a top view, the outer flange section may have an annular shape. The outer flange section may have any of the respective features of an outer flange section, particularly with regard to its dimensions, which are described below with reference to the drawings.

[0035] The inner flange section can refer to a portion of the electrode connection that is located, or designed to be located, inside the battery housing. The inner flange section can refer to a portion of the electrode connection that extends radially outward from the body section within the battery housing. The inner flange section can also extend axially from the body section to form inclined surfaces in a radial cross-sectional view. Approximately, the inner flange section can have the shape of a hollow cone section (without a vertex). The thickness of the inner flange section can be measured in the axial direction and can vary with distance from the body section. In a top view, the inner flange section can have an annular shape.The inner flange section can have any of the respective features of an inner flange section, particularly with regard to its dimensions, which are described below with reference to the drawings.

[0036] The flat section (flat section, planar section) can refer to a portion of the electrode connection that is located, or designed to be located, within the battery housing. The flat section can provide a contact surface to be coupled with another component of a battery, such as a current collector (plate) or an electrode tab. The flat section can be, or comprise, a surface of the body section that faces axially. The flat section can also comprise a portion of the body section that forms the surface. The flat section can have any of the respective features of a flat section, particularly with respect to its dimensions, which are described below with reference to the drawings.

[0037] The seal provides a seal between the second end face of the battery can and the electrode terminal. Additionally or alternatively, the seal provides electrical insulation between the second end face of the battery can and the electrode terminal. For example, the seal can be designed and positioned so that the electrode terminal does not come into physical contact with the second face of the battery can. The seal can have any of the features of a seal described below with reference to the drawings.

[0038] A structure may comprise: a battery can configured to have an open side; an electrode connector passing through a perforation opening formed in a base of the battery can; and a seal arranged between the electrode connector and the perforation opening, wherein the electrode connector comprises: a body section inserted into the perforation opening; an outer flange section configured to extend along an outer surface of the base of the battery can from a circumference of one side of the body section exposed by the outer surface; an inner flange section configured to extend to an inner surface of the base of the battery can from a circumference of the other side of the body section exposed by the inner surface; and a flat section provided on an inner side of the inner flange section.

[0039] The flat section can be parallel to the inner surface of the second end face of the battery can. The flat section can be parallel to the inner surface of a base. Here, the base can refer to the second end face of the battery can unless otherwise specified.

[0040] The angle between the inner flange section and the inner surface of the second end face (the bottom) of the battery box can be 0 to 60° or 0° or more, 2° or more, 5° or more, or 10° or more, and 60° or less, 55° or less, 50° or less, 45° or less, or 40° or less.

[0041] A recess may be provided between the inner flange section and the flat section. The recess may be formed by a side wall of the body section extending axially from the flat section and a side wall of the inner flange section facing the flat section. The recess may surround the flat section. The recess may have the form of a groove in a cross-sectional view in the radial direction and an annular form in a top view in the axial direction. The recess may have any of the features of a recess described below with reference to the drawings.

[0042] The recess can have a cross-sectional structure of an asymmetrical groove. The asymmetry can refer to the cross-sectional view in the radial direction, which, due to the cylindrical symmetry of the electrode connection, may be invariant from the viewing angle. The asymmetrical groove can also refer to an asymmetry with respect to a plane that surrounds the axis of symmetry, i.e., extending in the axial and circumferential directions. For example, the angle between the side wall of the body section extending from the flat section and the axial direction may differ from the angle between the (inner) side wall of the inner flange section and the axial direction.

[0043] The asymmetrical groove can be formed between the side wall of the body section extending from the flat section and an inclined surface of the inner flange section. The inclined surface can refer to the inner side wall of the inner flange section described above. In other words, the asymmetrical groove can have a side wall of the flat section and an inclined surface of the inner flange section connected to one end of the side wall.

[0044] The side wall of the body section (which can also be referred to as the side wall of the flat section) can be perpendicular to the inner surface of the second end surface (the bottom) of the battery box.

[0045] The body section can taper in one direction from the second end face of the battery can to the flat section. The taper can refer to a shape in a cross-sectional view in the radial direction. The side wall can be inclined towards the flat section with respect to a plane extending in the axial and circumferential directions.

[0046] The inner flange section can have a thickness that decreases with increasing distance from the body section. The decrease can be continuous, gradual, stepwise, or any combination thereof.

[0047] The gasket can comprise an outer gasket and an inner gasket. The outer gasket can be positioned between the outer flange section and the outer surface of the second end face (the bottom) of the battery housing. The inner gasket can be positioned between the inner flange section and the inner surface of the second end face (the bottom) of the battery housing. The thickness of the inner gasket can vary in an outward direction, approximately radial. In other words, the inner gasket can have different thicknesses at different points along its length.

[0048] The thickness of the inner seal between an edge of the perforation opening and the inner flange section can be less than the thickness of the remainder of the inner seal. In other words, the inner seal can have a minimal thickness in a region between an edge of the perforation opening and the inner flange section. The area of ​​the inner seal located between the (inner) edge of the perforation opening, which is connected to the inner surface of the base, and the inner flange section can have a relatively smaller thickness than the other region. The edge can refer to an inner part of the second end face of the battery can that surrounds the perforation opening. This protrusion can be obtained by deformation of the electrode terminal such that a tip (i.e., an outermost section) of the inner flange section is bent towards the second end face of the battery can.As a result, the tip of the inner flange section can be pressed into the inner gasket, reducing its thickness at that point (to a minimum).

[0049] An area of ​​the inner seal located between the perforation opening and the body section can have a thickness that decreases with increasing distance from the outer flange section. The decrease can be continuous, stepwise, gradual, or any combination thereof.

[0050] The thickness of the inner gasket is minimal at one end of the inner flange section. A region of the inner gasket located between the inner surface of the base and an area near the end of the inner flange section may have a minimal thickness.

[0051] The (inner) edge of the perforation opening may include a surface facing the inner flange section. This surface of the perforation opening may be referred to as a facing surface. The edge may relate to an inner portion of the second end face of the battery can that surrounds the perforation opening. The facing surface may be inclined (slanted) with respect to a remainder (the closed section) of the second end face of the battery can. The edge of the perforation opening may have any of the features described below with reference to the drawings.

[0052] The inner gasket may extend further from the body section than the inner flange section, so that an end portion of the inner gasket may be exposed. The inner gasket may be designed to extend longer than the inner flange section, so that one end of it is exposed. Here, the exposed end portion or exposed end of the inner gasket may indicate that it extends radially beyond the inner flange section. Alternatively or additionally, exposure may mean that the corresponding part is visible in a top view in the axial direction.

[0053] The distance of the flat section from the inner surface of the second end face of the battery may be greater than or equal to the height of one end (the tip) of the inner seal, measured from the inner surface of the second end face of the battery can. Similarly, the height of the flat section, measured from the inner surface of the base, may be greater than or equal to the height of one end of the inner seal. Hereafter, a dimension or measure (height, width, length, distance, etc.) of one element that is "based on" another element may indicate that the respective dimension or measure of one element is measured from (or relative to) the other element. In this context, a height may refer to a dimension in the axial direction (i.e., be measured in that direction).

[0054] The height of the flat section can be greater than or equal to the height of the inner flange section. The heights can be measured from the inner surface of the second end face (the bottom) of the battery box.

[0055] The height of the inner flange section can be greater than the height of one end of the inner gasket. The heights can be measured from the inner surface of the second end face (the bottom) of the battery box.

[0056] The height of the inner flange section can be 0.5 mm to 3.0 mm, or 0.5 mm or more, or 0.7 mm or more, or 1.0 mm or more, or 1.5 mm or more, and 3.0 mm or less, 2.5 mm or less, 2.0 mm or less, or 1.5 mm or less. The height can be measured based on the inner surface of the bottom (the second end face) of the battery box.

[0057] The height of the electrode connection between an outer surface of the outer flange section and (an outer surface) of the flat section can be 4 mm to 7 mm, or 4 mm or more, or 4.5 mm or more, or 5 mm or more, or 5.5 mm or more, and 7 mm or less, 6.5 mm or less, 6 mm or less, or 5.5 mm or less. In an embodiment where the battery box is arranged with the second end face facing downwards, the outer surface of the outer flange section can be referred to as a lower surface.

[0058] The height of the outer flange section from the outer surface of the second end surface (the bottom) of the battery box can be 0.8 mm or more.

[0059] At least a portion of the outer gasket may be exposed to the outside of the outer flange section. The exposure width of the outer gasket, measured in a direction parallel to the outer surface of the battery can bottom, may be 0.1 mm to 1 mm, or 0.1 mm or more, or 0.2 mm or more, or 0.3 mm or more, or 0.4 mm or more, or 0.5 mm or more, and 1 mm or less, 0.9 mm or less, 0.8 mm or less, or 0.7 mm or less, or 0.6 mm or less. The exposure width may refer to the extent by which the outer gasket extends beyond the outer flange section in a plan view. The exposure width may be measured along the extent of the outer gasket and / or approximated in the radial direction.

[0060] The radius from the center of the body section to an edge of the outer flange section (i.e., the outer radius of the outer flange section) can be 10% to 70% of the radius of the second end face of the battery can. The outer radius of the outer flange section can be 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 70% or less, 65% or less, 60% or less, 55% or less, or 45% or less of the radius of the second end face of the battery can. The radii can be determined by the axis of symmetry of the battery can and / or the axis of symmetry of the electrode terminal.

[0061] The radius of the flat section can be 4% to 30% of the radius of the second end face of the battery can. Both the flat section of the electrode terminal and the second end face of the battery can may have a circular shape in a top view. The radius of the flat section can be measured from the center of the body section (i.e., the axis of symmetry of the electrode terminal) to an edge of the flat section. The radius of the flat section can be 4% or more, 5% or more, 7% or more, 10% or more, 15% or more, 20% or more, 30% or less, 27.5% or less, 25% or less, 22.5% or less, or 20% or less of the radius of the second end face of the battery can.

[0062] The compression ratio of the inner seal can be 30% to 90%, or 50% to 90%, or 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, or 60% or more, and 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, or 65% or less. The compression ratio can specify the ratio of the thickness change at a maximum compression point compared to the thickness before compression of the seal.

[0063] The inner seal may contain polybutylene terephthalate, polyethylene fluoride, or polypropylene.

[0064] Another aspect may relate to a cylindrical battery cell. The cylindrical battery cell may include an electrode assembly, a cylindrical battery can, an electrode terminal, a seal, and a sealing body. At least one of the cylindrical battery can, the electrode terminal, and the seal may be as described above.

[0065] The electrode assembly can comprise a first electrode plate, a second electrode plate, and a separator positioned between them. The electrode assembly can be wound such that it has a first end face and a second end face that are opposite each other. The electrode assembly can be wound such that it has an approximately cylindrical shape around an axis of symmetry that defines an axial (extension) direction, a radial direction, and a circumferential (tangential) direction. The first electrode plate can have an uncoated section located at the first end face of the electrode assembly. The second electrode plate can have an uncoated section located at the second end face of the electrode assembly. The uncoated sections can be arranged to extend (in the axial direction) beyond the separator.The electrode assembly can have any of the features of an electrode assembly as described below with reference to the drawings. The first electrode plate and the second electrode plate can each comprise a respective metal plate that is partially covered with an active compound, wherein a respective section of the first and second electrode plates that remains uncovered with an active compound can define the respective uncoated section.

[0066] The cylindrical battery box, which may also be referred to as a battery housing, can accommodate the electrode assembly. The battery box may be electrically connected to the first electrode plate. The battery box may have a (substantially) cylindrical shape, defining an axial direction, a radial direction, and a circumferential (tangential) direction. The battery box may have a first end face and a second end face that are opposite each other. The battery box may have any of the features of the battery box specified above and / or any of the features of a battery box described below with reference to the drawings.

[0067] The electrode connection can pass through a perforated opening formed in the second end face of the battery box. The electrode connection can be electrically connected to the second electrode plate. The electrode connection can have any of the features of the electrode connection specified above and / or any of the features of an electrode box described below with reference to the drawings.

[0068] The electrode connection can comprise a body section, an outer flange section, an inner flange section, and a flat section. The body section can extend through the perforation opening in / from the second end face of the battery box. The outer flange section can extend from the body section along an outer surface of the second end face of the battery box. The inner flange section can be located inside the battery box and extend outward from the body section. The flat section can be located inside the battery box and can be surrounded by the inner flange section. The body section, the outer flange section, the inner flange section, and / or the flat section can be configured as specified above and / or have any of the respective features as described below with reference to the drawings.

[0069] The seal can be positioned between the electrode connection and the perforation opening. The seal can have any of the features of the seal specified above and / or any of the features of a seal described below with reference to the drawings.

[0070] The sealing body can close the first end face of the battery can. The sealing body can seal an opening (i.e., an open section of the first end face) of the battery can. The sealing body can be designed to be insulated from the battery can. In particular, the sealing body can be designed to prevent liquid or solid material from escaping from inside the battery can through the first end face of the battery can to the outside of the battery can. While the battery can be electrically connected to one of the first and second electrode plates, the sealing body can be designed to be free from any electrical (electrochemical) potential of the first and second electrode plates. The sealing body can have any of the features of a sealing body as described below with reference to the drawings.

[0071] A cylindrical battery cell can comprise an electrode assembly, a cylindrical battery can, an electrode terminal, a seal, and a sealing body. The electrode assembly can include a first electrode plate and a second electrode plate in a sheet shape, wound with a separator positioned between them. The electrode assembly can have an uncoated section of the first electrode plate and an uncoated section of the second electrode plate, designed to extend from both ends and expose outside the separator. The cylindrical battery can is designed to house the electrode assembly and be electrically connected to the first electrode plate.The electrode connection can pass through (pierce or rivet (figuratively)) a perforation opening formed in the base of the battery box and can be electrically connected to the second electrode plate. The electrode connection can have a body section, an outer flange section, an inner flange section, and a flat section. The body section can be inserted into the perforation opening. The outer flange section can be designed to extend along an outer surface of the base of the battery box from a circumference exposed by the outer surface on one side of the body section. The inner flange section can be designed to extend from a circumference exposed by the inner surface on the other side of the body section to an inner surface of the base of the battery box. The flat section (flat section, planar section) can be provided on an inner surface of the inner flange section.The seal can be positioned between the electrode connection and the perforated opening. The seal body can be designed to seal an open end of the battery box, thus isolating it from the battery box.

[0072] The battery box can have a corrugated section. The corrugated section can be formed by indenting a side wall of the battery box at a section near the first end face. The side wall of the battery box can be a side wall of the battery box extending between the first and second end faces of the battery box. The sealing body can have a cover plate and a gasket located between the cover plate and the first end face of the battery box. The corrugated section can be formed in an area adjacent to the open end and pressed into the battery box. The sealing body can have a non-polarized cover plate and a gasket located between an edge of the cover plate and the open end of the battery box.No polarity can mean that the cover plate is free from the electrical (electrochemical) potential of the first and second electrode plates. For example, the cover plate may not be electrically connected to either of the first and second electrode plates.

[0073] The bead section can refer to a depressed section of the battery box. The battery box can be depressed at a location close to (near, adjacent to, or near) the first end face. The resulting circumferential depression can be referred to as the bead section of the battery box. The bead section can have any of the features of a bead section described below with reference to the drawings.

[0074] The cover plate can have a shape approximately similar to or identical to the opening of the first end face of the battery box in a top view, in the axial direction. The cover plate can be circular or polygonal in a top view. The opening in the first end face can also be circular or polygonal in a top view.

[0075] The battery box may further include a crimp section extending into the interior of the battery box, which is bent and configured to surround and secure the edge of the cover plate along with the gasket. The crimp section may have any of the features of a crimp section described below with reference to the drawings.

[0076] The cover plate may have a vent notch configured to rupture in response to internal battery pressure exceeding a threshold. In this context, rupture can be a process of losing structural integrity and, consequently, forming an opening through which fluid can pass. The vent notch may be such that it locally reduces the thickness of the cover plate (i.e., compared to the rest of the cover plate). The vent notch may be configured, for example, positioned, arranged, and dimensioned to cause rupture in response to a predetermined threshold. The vent notch may have any of the features described below with reference to the drawings.

[0077] For example, the threshold for a break in the vent notch can be in the range of 15 kgf / cm². 2 up to 35 kgf / cm² 2The threshold value can be 15 kgf / cm². 2 or more, 17.5 kgf / cm² 2 or more, 20 kgf / cm² 2 or more, 22.5 kgf / cm² 2 or more, or 25 kgf / cm² 2 or more, and 35 kgf / cm² 2 or less, 32.5 kgf / cm² 2 or less, 30 kgf / cm² 2 or less, 27.5 kgf / cm² 2 or less, or 25 kgf / cm² 2 or less. The pressure unit kgf / cm 2 can be equivalent to 98.0665 kPa in SI units.

[0078] The cylindrical battery cell may further comprise a first current collector plate coupled to the uncoated section of the first electrode plate. The first current collector plate may be designed (e.g., made of a material and having a shape such as) to electrically connect the first electrode plate and the battery housing. The first current collector plate may also be referred to as a first current collector. The first current collector plate may have any of the features of a corresponding current collector plate described below with reference to the drawings.

[0079] At least one edge portion of the first current collector plate cannot be in contact with the uncoated section of the first electrode plate. The edge portion of the first current collector plate can be positioned between the bead section and the seal and secured by the crimp section. Accordingly, if the battery can and / or the cover plate are compressed axially during a battery cell manufacturing process, the surface contact between (the edge portion) of the first current collector plate and (the bead section) of the battery can may increase and / or decrease.

[0080] At least one edge portion of the first current collector plate can be fixed by welding to an inner surface (i.e. inner circumference, inside of the recess) of the bead section adjacent to the crimp section.

[0081] The cylindrical battery cell may further comprise a second current collector plate coupled to the uncoated portion of the second electrode plate. The second current collector plate may be designed (e.g., made of a single material and having a specific shape) to electrically connect the second electrode plate and the battery housing. The second current collector plate may also be referred to as a second current collector. The second current collector plate may have any of the features of a corresponding current collector plate described below with reference to the drawings.

[0082] At least part of the second current collector plate can be coupled to the flat section of the electrode terminal. In particular, the second current collector plate can be physically and electrically coupled to the flat section of the electrode terminal.

[0083] The second current collector plate and the flat section of the electrode terminal can be welded together. The weld between the second current collector plate and the flat section of the electrode terminal can achieve a tensile strength of 2 kgf or more. In other words, the tensile strength of the weld between the second current collector plate and the flat section of the electrode terminal can be 2 kgf or more. The tensile strength can be 2.5 kgf or more, 3 kgf or more, 4 kgf or more, 5 kgf or more, 30 kgf or less, 25 kgf or less, 20 kgf or less, 15 kgf or less, 10 kgf or less, or 5 kgf or less. The tensile strength can refer to the tensile strength of a material. The tensile strength can be determined using a conventional universal testing machine (UTM).

[0084] The second current collector plate can be welded to the flat section of the electrode terminal according to a predetermined pattern. The converted diameter (equivalent diameter) of a weld pattern exposed on a surface of the second current collector plate can be 2 mm or more, 2.5 mm or more, 3 mm or more, 3.5 mm or more, or 4 mm or more.

[0085] The diameter of the flat section of the electrode terminal can be 3 mm to 14 mm, or 3 mm or more, or 4 mm or more, 5 mm or more, or 6 mm or more, and 14 mm or less, 12 mm or less, 10 mm or less, 8 mm or less, or 6 mm or less. As stated above, the diameter of the flat section of the electrode terminal can be determined from the center or axis of symmetry of the electrode terminal. As stated above, the flat section can have a circular shape in the axial direction when viewed from above.

[0086] The ratio of the area of ​​the weld pattern exposed on a surface of the second current collector plate to the area of ​​the flat section of the electrode terminal can be 2.04% to 44.4%, or 2.04% or more, 2.5% or more, 3% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 30% or more, and 44.4% or less, 40% or less, 38% or less, 35% or less, or 30% or less. The areas can be determined as a projection in the axial direction (i.e., in a top view).

[0087] The cylindrical battery cell may further comprise an insulator arranged between the second current collector plate and an inner circumference of the second end face of the battery can, and between an inner circumference of a side wall of the battery can and the electrode assembly. The insulator may be designed (i.e., made of a material, having a shape, and / or arranged) to provide electrical insulation between the electrode assembly and the battery can. The insulator may have any of the features of an insulator described below with reference to the drawings.

[0088] The insulator may have a weld hole designed to expose the flat section of the electrode terminal facing the second current collector plate. The insulator may cover the second current collector plate and one edge of the second end face of the electrode assembly. Welding of the second current collector plate to the second end face of the electrode assembly may be permitted through the weld hole in the insulator. The weld hole may be designed as described below with reference to the drawings. The term "weld hole" may collectively refer to several holes designed for this purpose.

[0089] The height of the flat section of the electrode terminal from the inner surface of the second end face of the battery can can be less than or equal to the thickness of the insulator. In other words, the height from the inner surface of the bottom of the battery can to the flat section of the electrode terminal can be less than or equal to the thickness of the insulator.

[0090] The seal may comprise an outer seal and an inner seal. The outer seal may be positioned between the outer flange section and the outer surface of the battery box base. The inner seal may be positioned between the inner flange section and the inner surface of the battery box base. Optionally, the outer seal and / or the inner seal may have any of the respective features specified above and / or described below with reference to the drawings.

[0091] One end of the inner gasket may be exposed to the outside of the inner flange section. In a top view, the inner gasket may extend radially beyond the inner flange section. The inner gasket may extend further radially than the inner flange section itself. In a top view, the (radial) end of the inner gasket may protrude from the inner flange section and thus be visible.

[0092] The weld opening may expose the flat section of the electrode connection and / or the inner flange section.

[0093] The welding opening can expose the flat section of the electrode connection, the inner flange section, and the inner seal.

[0094] The cylindrical battery cell can further comprise a first busbar connection and a second busbar connection. The first busbar connection can be electrically coupled to a surface of the electrode terminal. The second busbar connection can be electrically coupled to the outer surface of the base of the battery box. In a battery module, battery pack, or vehicle, either the first busbar connection or the second busbar connection can be used to conduct electrical current from (and to) the cylindrical battery cell to an electrical load, such as an electric motor.

[0095] The first busbar terminal can be located on (overlapping, contacting, coupled with) the electrode terminal to form a first overlap area. The second busbar terminal can be located on (overlapping, contacting, coupled with) the outer surface of the battery can bottom to form a second overlap area. The diameter of the electrode terminal and the width of the outer surface of the battery can bottom can satisfy the following relational expression: W1≤E1≤D−2Rd−2G−2W2 E2=0.5*(D−2Rd−2G−E1)

[0096] (E1: Diameter of the electrode connection, E2: Width of an exposed area parallel to an area of ​​the electrode connection in the outer surface of the base of the battery box, D: Outer diameter of the battery box, R d: Width of a circular area at an edge of the battery box, measured on a plane, G: Exposure width of the outer seal by an edge of the electrode terminal, W1: Maximum value among distances between any two points selected in an edge of the first overlap area, W2: Maximum value among distances between two points where a plurality of linear lines passing through the center of the electrode terminal meet an edge of the second overlap area).

[0097] A ratio obtained by dividing the diameter of the cylindrical battery cell by its height can be greater than 0.4, or greater than 0.35, or greater than 0.42, or greater than 0.45, or greater than 0.48, or greater than 0.5, or greater than 5.5, or greater than 5.7, and less than 1.0, or less than 0.9, or less than 0.8, or less than 0.7, or less than 0.6. In particular, the diameter of the cylindrical battery cell can be between 40 mm and 50 mm, especially 46 mm, while the height of the cylindrical battery cell can be between 70 mm and 90 mm, especially 80 mm.

[0098] According to another aspect, a battery pack can be provided which has one or more cylindrical battery cells as described above.

[0099] The cylindrical battery cells can be arranged in one or more columns. The cylindrical battery cells can be arranged so that their electrode terminals and the second end faces of the battery cans of the cylindrical battery cells are on top. In other words, the electrode terminal and the outer surface of the bottom of the battery can of each cylindrical battery cell can be oriented so that they point upwards.

[0100] The battery pack can have multiple busbars configured to connect the multiple cylindrical battery cells in series and parallel. The busbars can be arranged above the cylindrical battery cells. Each busbar can have a body section, multiple first busbar terminals, and multiple second busbar terminals. The body section of each busbar can be designed to extend between the electrode terminals of adjacent cylindrical battery cells. The first busbar terminals can each be designed to extend laterally from the body section and be electrically coupled to the electrode terminal of the cylindrical battery cell located in that later direction.The second busbar connections can each be designed to extend in the opposite lateral direction from the body section and are electrically coupled to the outer surface of the bottom of the battery box of the cylindrical battery cell, which is located in the opposite lateral direction.

[0101] The AC resistance of the cylindrical battery cell, measured between the electrode terminal and the outer surface of the bottom of the battery casing, can be 4 milliohms (mΩ) or less, 3.5 mΩ or less, 3 mΩ or less, or 2.8 mΩ or less. The resistance can be 0.5 mΩ or more, or 1.0 mΩ or more.

[0102] In another aspect, a vehicle has the cylindrical battery cell as specified above and / or the battery pack described above. BENEFICIAL EFFECTS

[0103] According to one embodiment of the present disclosure, it is possible to reduce the internal resistance of a cylindrical battery cell and increase the energy density by improving an electrode connection structure of the cylindrical battery cell in order to increase the space efficiency in a battery box.

[0104] According to a further embodiment of the present disclosure, it is possible to solve the internal heating problem caused during fast charging by improving the electrode connection structure of a cylindrical battery cell to increase the cross-sectional area of ​​a current path.

[0105] According to yet another embodiment of the present disclosure, the electrical wiring for the series and / or parallel connection of the cylindrical battery cells can be carried out on one side of the cylindrical battery cells.

[0106] According to yet another embodiment of the present disclosure, it is possible to provide a battery pack manufactured using the cylindrical battery cell with an improved structure and a vehicle comprising the battery pack. FIGURE DESCRIPTION

[0107] The accompanying drawings illustrate examples and, together with the preceding disclosure, serve to further clarify the technical features of this disclosure. This disclosure is not limited to the drawings. Fig. Figure 1 is a top view showing the structure of an electrode plate used for a conventional tabless cylindrical battery cell. Fig. Figure 2 is a diagram showing a winding process of an electrode assembly contained in the conventional tabless cylindrical battery cell. Fig. Figure 3 is a diagram illustrating the welding process of a current collector plate to a curved surface of an uncoated section in the electrode assembly of Fig. 2 shows. Fig. Figure 4 is a sectional view of the conventional tabless cylindrical battery cell along a longitudinal direction (Y). Fig. Figure 5 is a sectional view showing the rivet structure of an electrode connection. Fig. 6a is an enlarged sectional view showing a section that is in Fig. 5 is indicated by a dotted circle. Fig. Figure 6b is a partially enlarged sectional view showing a rivet structure of an electrode connection. Fig. Figure 6c is a schematic view illustrating a welding pattern and a converted diameter. Fig. Figure 7a is a sectional view of a cylindrical battery cell according to an embodiment of the present disclosure along a longitudinal direction (Y). Fig. Figure 7b is a sectional view of a cylindrical battery cell along a longitudinal direction (Y). Fig. Figure 8 is a top view showing an example of an electrode plate structure. Fig. Figure 9 is a sectional view of an electrode assembly in which a segment structure of an uncoated section of the electrode plate is applied to a first electrode plate and a second electrode plate along the longitudinal direction (Y). Fig. Figure 10a is a sectional view of an electrode assembly in which the uncoated section is bent along the longitudinal direction (Y). Fig. Figure 1ob is a perspective view of the electrode assembly where the uncoated section is bent. Fig. Figure 11 is a top view showing that a large number of cylindrical battery cells are connected in series and parallel using a busbar. Fig. 12a is a partially enlarged view of Fig. 11. Fig. 12b and Fig. Figure 12c schematically shows exemplary parameters used in defining an electrode connection diameter and an exposure width of an outer surface of a second end surface of a battery can. Fig. Figure 13 is a diagram showing a schematic configuration of a battery pack with cylindrical battery cells. Fig. Figure 14 is a diagram showing a schematic configuration of a vehicle with the battery pack. EXAMPLES

[0108] Examples are described in detail below with reference to the accompanying drawings. At the outset of the description, it should be made clear that the terms used in the description and the accompanying claims are not to be interpreted as being limited to general and literal meanings, but rather are to be interpreted on the basis of the meanings and concepts that correspond to the technical aspects of the present disclosure, based on the principle that the inventor is permitted to define terms appropriately for the best possible explanation.

[0109] Therefore, the description proposed here serves only the purpose of illustration and is not intended to limit the scope of the disclosure, although it is clear that other equivalents and modifications could be made to it without deviating from the scope of the disclosure.

[0110] Furthermore, to facilitate understanding of the invention, some components in the accompanying drawings may not be drawn to scale, and their dimensions may be exaggerated. Additionally, the same components may be assigned the same reference numerals in different embodiments.

[0111] When it is stated that two tasks are identical, this means that these tasks are "essentially identical." Accordingly, essentially identical tasks may exhibit variations that are considered minor in engineering, for example, variations within 5%. Furthermore, when it is stated that certain parameters are uniform within a predetermined range, this can mean that the parameters are uniform with respect to an average.

[0112] A cylindrical battery cell may include an electrode terminal that passes through a second end face of a battery can. The battery cell and the electrode terminal may have any of the features specified above. In particular, the battery cell and the electrode terminal may each have a cylindrical geometry that defines a respective axial direction, a respective radial direction, and a respective circumferential direction. The battery can and the electrode terminal may be arranged such that their axial, radial, and circumferential directions coincide.

[0113] Fig. Figure 5 is a sectional view showing the structure of an electrode connection 50, and Fig. 6a is an enlarged sectional view showing a section that is in Fig. 5 is indicated by a dotted circle. Here, the expression "rivet on / through" can figuratively indicate that it is inserted and deformed in a similar way to the common rivet, but without a second part being attached to the battery box.

[0114] With reference to the Fig. 5 and Fig. 6a the structure of the electrode connection 50 according to the embodiment can comprise a cylindrical battery box 51 with an open side, an electrode connection 50 passing through a perforation opening 53 formed in a second end surface 52 of the battery box 51, and a seal 54 arranged between the electrode connection 50 and the perforation opening 53.

[0115] The battery box 51 is made of a conductive metal material. For example, the battery box 51 could be made of steel, aluminum, stainless steel, or the like, but the present disclosure is not limited to such materials. The inner and outer surfaces of the battery box 51 could be coated with a nickel plating layer.

[0116] The electrode terminal 50 is made of a conductive metal material. For example, the electrode terminal 50 could be made of steel, aluminum, stainless steel, or the like, but the present disclosure is not limited to such materials. The electrode terminal 50 could be made of a 10-series aluminum alloy, which is easily inserted and deformed for fixing (i.e., figuratively riveting) and has low resistance.

[0117] The seal 54 can be made of a polymer resin with insulating and elastic properties. In one example, the seal 54 can be made of polypropylene, polybutylene terephthalate, polyethylene fluoride, or the like, but the present disclosure is not limited thereto.

[0118] The electrode connection 50 can comprise a body section 50a inserted into the perforation opening 53, an outer flange section 50b extending along an outer surface 52a from the circumference of one side of the body section 50a and exposed through the outer surface 52a of the second end surface 52 of the battery box 51, an inner flange section 50c extending to an inner surface 52b from the circumference of the other side of the body section 50a and exposed through the inner surface 52b of the second end surface 52 of the battery box 51, and a flat section 50d provided within the inner flange section 50c.

[0119] The flat section 50d and the inner surface 52b of the second end surface 52 of the battery box 51 can be parallel to each other. Here, the term "parallel" essentially means parallel when viewed with the naked eye.

[0120] According to one embodiment, the angle (θ) between the inner flange section 50c and the inner surface 52b of the second end face 52 of the battery box 51 can range from 0 to 60°. The size of the angle is determined by the crimping strength when the electrode terminal 50 is installed in the perforated opening 53 of the battery box 51 by a crimping process. In one example, the angle (θ) can decrease to 0° with increasing crimping strength. If the angle exceeds 60°, the sealing effect of the gasket 54 may be impaired.

[0121] According to another embodiment, a recess 55 can be provided between the inner flange section 50c and the flat section 50d. The recess 55 can have a cross-sectional structure of an asymmetrical groove. In one example, the asymmetrical groove can have an approximately V-shape. The asymmetrical groove can have a side wall 55a of the flat section 50d and an inclined surface 55b of the inner flange section 50c, which is connected to one end of the side wall 55a. The side wall 55a can be substantially perpendicular to the inner surface 52b of the second end surface 52 of the battery box 51. The term "vertical" means essentially vertical when viewed with the naked eye. As will be explained later, the side wall 55a can be inclined in the direction of the flat section 50d.The recess 55 is formed by the shape of a crimping device when the electrode connection 50 is installed in the perforation opening 53 of the battery box 51 by a crimping process.

[0122] The thickness of the inner flange section 50c can gradually decrease with increasing distance from the body section 50a of the electrode connection 50.

[0123] According to a further embodiment, the seal 54 can comprise an outer seal 54a arranged between the outer flange section 50b and the outer surface 52a of the second end surface 52 of the battery box 51, and an inner seal 54b arranged between the inner flange section 50c and the inner surface 52b of the second end surface 52 of the battery box 51. The outer seal 54a and the inner seal 54b are separated based on the outer surface 52a of the bottom of the battery box 51.

[0124] The outer seal 54a and the inner seal 54b can have different thicknesses depending on their location. A region of the inner seal 54b located between the inner flange section 50c and an inner edge 56 of the perforation opening 53, which is connected to the inner surface 52b of the second end surface 52 of the battery box 51, can have a relatively smaller thickness. A point of minimal thickness can be present in a sealing area located between the inner edge 56 of the perforation opening 53 and the inner flange section 50c. Additionally, the inner edge 56 of the perforation opening 53 can include a facing surface 57 that faces the inner flange section 50c.

[0125] Meanwhile, the top and bottom surfaces of the inner wall of the perforated opening 53 are chamfered (corner-cut) perpendicular to the second end face 52 of the battery box 51 to form a surface that tapers towards the electrode terminal 50. However, the top and / or bottom surfaces of the inner wall of the perforated opening 53 can be converted into a smooth curved surface. In this case, the stress exerted on the seal 54 near the top and / or bottom surfaces of the inner wall of the perforated opening 53 can be reduced.

[0126] The inner seal 54b can extend longer than the inner flange section 50c, while forming an angle of 0 to 60 with the inner surface 52b of the second end surface 52 of the battery box 51.

[0127] In another embodiment, the height (H1) of the flat section 50d, based on the inner surface 52b of the second end surface 52 of the battery box 51, can be greater than or equal to the height (H2) of the end of the inner seal 54b. Additionally, the height (H1) of the flat section 50d, based on the inner surface 52b of the second end surface 52 of the battery box 51, can be greater than or equal to the height (H3) of the end of the inner flange section 50c. Here, height H2 is the maximum height of the end of the inner seal 54b, measured based on the inner surface 52b. Additionally, height H3 is the maximum height of the end of the inner flange section 50c, measured based on the inner surface 52b.

[0128] If the height parameters H1, H2 and H3 meet the conditions, it can be prevented that the inner flange section 50c and the inner seal 54b collide with other components.

[0129] The height (H3) of the inner flange section 50c can be from 0.5 mm to 3.0 mm. If the height (H3) of the inner flange section 50c is less than 0.5 mm, sufficient sealing properties are not guaranteed. Additionally, if the height (H3) of the inner flange section 50c exceeds 3 mm, the interior space of the battery box 51 that can be occupied by the electrode assembly is reduced.

[0130] The height (H4) of the electrode terminal 50 can be from 1.5 mm to 7 mm. The height (H4) of the electrode terminal 50 corresponds to the distance from the lower surface of the outer flange section 50b to the flat section 50d. If the height (H4) of the electrode terminal 50 is less than 1.5 mm, it is difficult to increase the height of the inner flange section 50c sufficiently to ensure adequate sealing properties due to the thickness of the second end face 52 of the battery housing 51. For example, the thickness of the second end face 52 of the battery housing 51 is approximately 0.5 mm to 1 mm. Furthermore, if the height (H4) of the electrode terminal 50 exceeds 7 mm, the internal volume of the battery housing 51 that can be occupied by the electrode assembly decreases, and the cell height increases, thus correspondingly reducing the energy density per unit volume.If H3 and H4 meet the above numerical ranges, it is possible to adequately ensure the sealing properties of the electrode terminal 50 without reducing the space inside the battery box 51.

[0131] In another embodiment, based on the outer surface area 52a of the base 54 of the battery box 51, the height (H5) of the outer flange section 50b can be 0.8 mm or more. If the height (H5) of the outer flange section 50b is less than 0.8 mm, the outer flange section 50b may deform when the electrode terminal 50 is inserted. The thickness of the outer seal 54a is 0.3 mm or more, taking into account its insulating and sealing properties. Considering the thickness of the outer seal 54a, if the height of the outer flange section 50b decreases to less than 0.8 mm, the outer flange section 50b becomes so thin that it is difficult to ensure sufficient mechanical rigidity. This is particularly critical if the electrode terminal 50 is made of aluminum.Meanwhile, the height of the outer flange section 50b can be suitably adjusted, taking into account the available space in the upper part of the cell. By way of example, the height of the outer flange section 50b can be set to 2 mm or less, or 3 mm or less, or 4 mm or less, but the present disclosure is not limited thereto.

[0132] According to yet another embodiment, at least a section of the outer seal 54a can be exposed to the outside of the outer flange section 50b of the electrode terminal 50. The outer seal 54a serves to insulate the electrode terminal 50 and the outer surface 52a, which has the opposite polarity to the electrode terminal 50, from each other. For electrical isolation of the electrode terminal 50 and the outer surface 52a, the exposure width (G) of the outer seal 54a can be 0.1 mm to 1 mm. If the exposure width (G) is less than 0.1 mm, the electrical isolation of the electrode terminal 50 and the outer surface 52a can be interrupted in one plane when a charge / discharge cycle is performed at a high current rate (c-rate) of 300 A or more.Additionally, if the exposure width (G) exceeds 1 mm, the electrical insulating effect is not further increased, but rather the area of ​​the outer surface 42a, which is used as a surface of the negative electrode, is reduced, thus reducing the contact area of ​​a component (e.g. a busbar) used for an electrical connection.

[0133] In yet another embodiment, the diameter of the flat section 50d of the electrode terminal 50 can be determined taking into account the weld strength between the current collector plate and the flat section 50d. The tensile strength of the weld section between the flat section 50d and the current collector plate can be at least 2 kgf or more, or 5 kgf or more, or 6 kgf or more, or 7 kgf or more, or 8 kgf or more, or 9 kgf or more, or 10 kgf or more. It is desirable to increase the tensile strength of the weld section as much as possible within a permissible range by selecting the most suitable welding process.

[0134] To meet the tensile strength requirement of the weld section, the diameter of the weld pattern formed on the flat section 50d can be at least 2 mm. If the area (S) of the weld bead appearing on the surface of the weld section is converted into an area (πr 2 ) of a circle is converted, the diameter of the weld pattern can be expressed as a converted diameter (equivalent diameter) (2·(S / π) 0,5 The diameter of the corresponding circle is defined. The weld pattern can be continuous or discontinuous. If the weld pattern is not a circle, the converted diameter can be determined from a maximum value among the distances between the center of the flat section 50d and an outer boundary of the weld pattern.

[0135] The flat section 50d of the electrode terminal 50 corresponds to a weldable area. The diameter of the weldable area can be between 3 mm and 14 mm. If the diameter of the weldable area is less than 3 mm, it is difficult to ensure a weld pattern with a diameter of 2 mm or more. In particular, when forming the weld pattern using laser welding, it is difficult to ensure a weld pattern with a diameter of 2 mm or more due to laser beam interference. If the diameter of the weldable area exceeds 14 mm, the diameter of the outer flange section 50b of the electrode terminal 50 becomes too large, and therefore it is difficult to adequately weld the area of ​​the outer surface 52a of the second end surface 52 of the battery socket, which is to be used as the negative electrode area.

[0136] Taking into account the diameter condition of the weld pattern and the diameter condition of the weldable area, the ratio of the area of ​​the weld pattern to the area of ​​the weldable area required to ensure a tensile strength of the weld section of at least 2 kgf or more can be 2.04% (π1 2 / π7 2 ) to 44.4% (π1 2 / π1.5 2 ).

[0137] In another embodiment, the radius (R1) from the center of the body section 50a to the edge of the outer flange section 50b can be 10 to 70% of the radius (R2) of the second end surface 52 of the battery box 51.

[0138] If R1 is small, the welding space is insufficient when wiring a component (a busbar) used for the electrical connection of the electrode terminal 50. Additionally, if R1 is large, the welding space decreases when welding a component (a busbar) for the electrical connection to the outer surface 52a of the second end surface 52 of the battery box 51, with the exception of the electrode terminal 50.

[0139] When the ratio R1 / R2 is set between 10 and 70%, it is possible to properly ensure the welding space for the electrode connection 50 and the outer surface 52a of the second end surface 52 of the battery box 51.

[0140] Additionally, the radius (R3) from the center of the body section 50a of the electrode connection 50 to the edge of the flat section 50d can be 4% to 30% of the radius (R2) of the second end surface 52 of the battery box 51.

[0141] If R3 is small, the welding area becomes insufficient when welding a current collector plate to the flat section 50d of the electrode terminal 50, and the welding area of ​​the electrode terminal 50 decreases, thereby increasing the contact resistance. Additionally, R3 must be smaller than R1; if R3 becomes larger, the thickness of the inner flange section 50c decreases, and the strength of the inner flange section 50c, which compresses the seal 54, weakens, potentially impairing the sealing capacity of the seal 54.

[0142] When R3 / R2 is set between 4% and 30%, the welding process can be easily carried out by adequately securing the welding area between the flat section 50d of the electrode terminal 50 and the current collector plate, and it is also possible to reduce the contact resistance of the welding area and prevent the sealing ability of the seal 54 from deteriorating.

[0143] According to one embodiment of the present disclosure, the structure of the electrode terminal 50 can be formed using a riveting device that moves up and down. First, a preform (not shown) of the electrode terminal 50 is inserted into the perforated opening 53 formed in the second end face 52 of the battery box 51 by positioning the seal 54. The preform refers to an electrode terminal before it is inserted and formed (i.e., figuratively: riveted).

[0144] Next, the crimping device is inserted into the interior of the battery box 51. The crimping device has a groove and a projection that correspond to the final shape of the electrode terminal 50 on the surface opposite the preform, in order to form the electrode terminal 50 by inserting and deforming the preform.

[0145] Next, the riveting device is moved downwards to perform a compression forming of the upper section of the preform, so that the preform is converted into a riveted electrode connection 50.

[0146] While the preform is pressed through the crimping device, the outer seal 54a, located between the outer flange section 50b and the outer surface 52a of the second end surface 52 of the battery box 51, is elastically compressed, thus reducing its thickness. Additionally, because the area of ​​the inner seal 54b located between the inner edge 56 of the perforation opening 53 and the preform is elastically compressed by the inner flange section 50c, the thickness of this area is reduced more than in other areas. In particular, in the area described in Fig. The area indicated by a dotted circle in section 6a significantly reduces the thickness of the inner seal 54b. Accordingly, the sealing and airtightness between the riveted electrode connection 50 and the battery box 51 are significantly improved.

[0147] The seal 54 is compressed sufficiently to ensure a desired sealing strength without being physically damaged in the process of inserting and deforming the preform.

[0148] The compression ratio of the seal 54 can range from 30% to 90%. The minimum compression ratio (30%) corresponds to a minimum compression ratio required to ensure the sealing properties of the electrode connection 50. The maximum compression ratio (90%) corresponds to the maximum compression ratio achievable without physically damaging the seal 54.

[0149] For example, if the seal 54 is made of polybutylene terephthalate, it may be advantageous for the seal 54 to have a compression ratio of 50% or more at the point where the seal 54 is compressed to a minimum thickness. The compression ratio is the ratio of the thickness change before and after compression with respect to the thickness before compression.

[0150] The compression ratio is determined for the inner seal 54b. That is, the compression ratio can be defined as the ratio of the thickness change at a maximum compression point compared to the thickness of the inner seal 54b before compression. This definition is applied identically in the following text. The thickness of the inner seal 54b before compression can be uniform, and a maximum compression point can be located near the inner edge 56.

[0151] In another example, if the seal 54 is made of polyfluoroethylene, it may be advantageous for the seal 54 to have a compression ratio of 60% or more at the point where the seal 54 is compressed to a minimum thickness. The compression ratio is determined for the inner seal 54b.

[0152] In yet another example, if the seal 54 is made of polypropylene, it may be advantageous for the seal 54 to have a compression ratio of 60% or more at the point where the seal 54 is compressed to a minimum thickness. The compression ratio is determined for the inner seal 54b.

[0153] The crimping process can be carried out in several stages on the upper section of the preform by moving the crimping device vertically at least twice. This means the preform can be deformed multiple times by performing the crimping process in several stages. During this process, the pressure applied to the crimping device can be gradually increased. In this way, the stress exerted on the preform is distributed over several cycles, preventing damage to the seal 54 during the crimping process. In particular, when the area of ​​the inner seal 54b located between the inner edge 56 of the perforation opening 53 and the preform is intensely compressed by the inner flange section 50c, damage to the seal is minimized by performing the crimping process in several stages.

[0154] After the compression molding on the preform has been completely carried out using the crimping device, the structure of the electrode connection 50 can be separated from the battery box 51 as shown in Fig. 6a will be shown and received.

[0155] According to the foregoing embodiment, the crimping device performs a compression forming operation on the upper section of the preform by moving it vertically within the battery box 51. In some cases, a rotary device used in the prior art can be employed to perform a compression forming operation on the preform.

[0156] However, the rotary device rotates in a state where it is inclined at a predetermined angle with respect to the central axis of the battery box 51. Therefore, the rotary device, with its large radius of rotation, can collide with the inner wall of the battery box 51. Additionally, the length of the rotary device increases if the battery box 51 has a large depth. In this case, the compression molding process on the preform cannot be carried out properly if the radius of rotation at the end of the rotary device increases. Therefore, it is more effective to perform compression molding using a riveting device rather than a rotary device.

[0157] Meanwhile, the electrode connection 50 can have different structures depending on the design of the preform and / or the riveting device and / or the seal 54 and the magnitude of the pressure exerted on the preform during the riveting process.

[0158] Fig. Figure 6b is a partially enlarged sectional view showing the structure of an electrode connection 50' according to another embodiment of the present disclosure.

[0159] With reference to Fig. 6b According to another embodiment, the electrode connection 50' has a structure in which the inner flange section 50c is inserted and deformed to be substantially parallel to the inner surface 52b of the second end surface 52 of the battery box 51. Therefore, the angle formed by the surface of the inner flange section 50c with respect to the inner surface 52b of the second end surface 52 of the battery box 51 is substantially close to 0°, and the height (H3) of the inner flange section 53c is less than the height (H2) of the inner seal 54b. Additionally, the inner edge 57 of the perforation opening 53 has an arc shape with a predetermined curvature. Additionally, the side wall of the edge of the flat section 50d has a structure inclined towards the flat section 50d.

[0160] The thickness of the inner seal 54b can gradually decrease upwards, decreasing to its minimum thickness near the end of the inner flange section 53c and then increasing slightly towards the top. The compression structure of this inner seal 54b can further improve the sealing properties of the electrode connection 50'. The compression ratio of the inner seal 54b can be calculated at the point of minimum thickness near the end of the inner flange section 53c.

[0161] The structure of the electrode connection 50, 50' according to the embodiments described above in the present disclosure can be applied to a cylindrical battery cell with a form factor of more than 21700.

[0162] Recently, when cylindrical battery cells are applied to electric vehicles, their form factor has increased compared to conventional forms like 18650, 21700, and similar cells. This increase in form factor results in higher energy density, improved thermal runaway resistance, and better cooling efficiency.

[0163] Additionally, as will be explained later, the electrical wiring can be carried out on one side of the cylindrical battery cell, to which the electrode terminal structure 50, 50' is applied. Furthermore, the electrode terminal 50, 50' with this structure has a large cross-sectional area and low resistance, making it very suitable for fast charging.

[0164] The cylindrical battery cell to which the structure of the electrode terminal 50, 50' of the present disclosure is applied can have a form factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery cell by the height, namely a ratio of diameter (Φ) to height (H)) that is greater than about 0.4.

[0165] Here, the form factor refers to a value that specifies the diameter and height of a cylindrical battery cell. The cylindrical battery cell could be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. In the numerical value representing the form factor, the first two digits indicate the cell's diameter, the next two digits indicate the cell's height, and the final digit, "0," indicates that the cell's cross-section is circular. If the cell's height exceeds 100 mm, the final digit, 0, can be omitted, as a three-digit number is required to specify the cell's height.

[0166] A battery cell can be a cylindrical battery cell with an approximately cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0167] A battery cell according to another embodiment can be a cylindrical battery cell with a substantially cylindrical shape, the diameter of which is approximately 48 mm, the height of which is approximately 75 mm and the form factor ratio of which is 0.640.

[0168] A battery cell according to yet another embodiment can be a cylindrical battery cell with an approximately cylindrical shape, the diameter of which is approximately 48 mm, the height of which is approximately 110 mm and the form factor ratio of which is 0.418.

[0169] A battery cell according to yet another embodiment can be a cylindrical battery cell with an approximately cylindrical shape, the diameter of which is approximately 48 mm, the height of which is approximately 80 mm and the form factor ratio of which is 0.600.

[0170] A battery cell according to yet another embodiment can be a cylindrical battery cell with an approximately cylindrical shape, the diameter of which is approximately 46 mm, the height of which is approximately 80 mm and the form factor ratio of which is 0.575.

[0171] Traditionally, battery cells with a form factor ratio of approximately 0.4 or less were used. That is, traditionally, 18650 cells, 21700 cells, and so on were used. The 18650 cell has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. The 21700 cell has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.

[0172] With reference to Fig. 6c, in order to meet the tensile strength condition of the weld section, the diameter of the weld pattern Wp formed on the flat section 50d can be at least 2 mm. If the area (S) of the weld pattern Wp appearing on the surface of the weld section is converted into an area (πr 2 ) of a circle is converted, the diameter of the weld pattern Wp can be expressed as a converted diameter (2·(S / π) 0,5 The weld pattern Wp can be defined as the diameter of the corresponding circle. The weld pattern Wp can be continuous or discontinuous. If the weld pattern Wp is not a circle, the converted diameter can be determined from a maximum value among the distances between the center of the flat section 50d and an outer boundary of the weld pattern Wp.

[0173] Fig. Figure 7a is a sectional view of a cylindrical battery cell 70 along a longitudinal direction (Y).

[0174] With reference to Fig. 7a The cylindrical battery cell 70 according to the embodiment includes an electrode assembly 71 of the jelly roll type, in which a first electrode plate and a second electrode plate are wound in a sheet shape with a separator arranged between them, such that an uncoated section 72 of the first electrode plate is exposed at a lower section and an uncoated section 73 of the second electrode plate is exposed at an upper section.

[0175] In one embodiment, the first electrode plate can be a negative electrode plate and the second electrode plate can be a positive electrode plate, or vice versa.

[0176] The method for winding the electrode assembly 71 is essentially the same as the method for winding the electrode assembly described in the manufacture of the electrode assembly described with reference to Fig. The conventional tabless cylindrical battery cell described in section 2 is used.

[0177] In the illustration of the electrode assembly 71, only the uncoated sections 72, 73, which extend so that they are exposed outside the separator, are illustrated in detail, and the winding structure of the first electrode plate, the second electrode plate and the separator is not illustrated in detail.

[0178] The cylindrical battery cell 70 also contains a cylindrical battery box 51, which accommodates the electrode assembly 71 and is electrically connected to the uncoated section 72 of the first electrode plate.

[0179] Preferably, one side (lower section) of the battery box 51 is open. In addition, the second end surface 52 of the battery box 51 has a structure in which the electrode connection 50 is inserted into the perforation opening 53 and deformed by a crimping process.

[0180] In particular, the electrode connection 50 can include a body section 50a that is inserted into the perforation opening 53, an outer flange section 50b that extends along the outer surface 52a from the circumference of one side of the body section 50a and that is exposed through the outer surface 52a of the second end surface 52 of the battery box 51, an inner flange section 50c that extends to the inner surface 52b from the circumference of the other side of the body section 50a and that is exposed through the inner surface 52b of the second end surface 52 of the battery box 51, and a flat section 50d that is provided on an inner side of the inner flange section 50c.

[0181] The electrode connection 50 can be accessed through the Fig. The electrode connection shown in 6b is replaced by 50'.

[0182] The cylindrical battery cell 70 can also include a seal 54 arranged between the electrode terminal 50 and the perforation opening 53.

[0183] The cylindrical battery cell 70 can also include a sealing body 74 that seals the open end of the battery box 51 to insulate it from the battery box 51. The sealing body 74 can have a non-polarized cover plate 74a and a seal 74b arranged between an edge of the cover plate 74a and the open end of the battery box 51.

[0184] The cover plate 74a can be made of a conductive metal material such as aluminum, steel, nickel, or the like. Additionally, the seal 74b can be made of polypropylene, polybutylene terephthalate, polyethylene fluoride, or the like, possessing insulating properties and elasticity. However, the present disclosure is not limited to these materials of the cover plate 74a and the seal 74b.

[0185] The cover plate 74a can have a vent notch 77 that ruptures when the pressure inside the battery box 51 exceeds a threshold. The vent notch 77 can be formed on either side of the cover plate 74a. The vent notch 77 can form a continuous or discontinuous circular pattern, a straight pattern, or any other pattern on the surface of the cover plate 74a. The depth and width of the vent notch 77 can be adjusted so that the vent notch 77 ruptures when the pressure inside the battery box 51 is in the range of 15 kgf / cm². 2 up to 35 kgf / cm² 2 lies.

[0186] The battery box 51 can have a crimp section 75 that extends into the interior of the battery box 51 and is bent to surround and fix the edge of the cover plate 74a together with the seal 74b in order to fix the sealing body 74 to the battery box 51.

[0187] The underside of the cover plate 74a can be located above the lower end of the crimp section 75. This creates a venting space under the cover plate 74a, so that when the venting notch 77 is broken, the gas can be released smoothly.

[0188] The battery box 51 can also have a beaded section 76, which is pressed into the battery box 51 in an area adjacent to its open end. The beaded section 76 supports the edge of the sealing body 74, in particular the outer circumferential surface of the seal 74b, when the sealing body 74 is fixed by the crimped section 75.

[0189] The cylindrical battery cell 70 may further comprise a first current collector plate 78, which is welded to the uncoated section 72 of the first electrode plate. The first current collector plate 78 is made of a conductive metal material such as aluminum, steel, nickel, or the like. At least one section 78a of the edge of the first current collector plate 78, which is not in contact with the uncoated section 72 of the first electrode plate, may be arranged between the beaded section 76 and the seal 74b and fixed by the crimped section 75. Optionally, at least one section 78a of the edge of the first current collector plate 78, adjacent to the crimped section 75, may be fixed to the inner circumference 76a of the beaded section 76 by laser welding, spot welding, ultrasonic welding, or the like.

[0190] The cylindrical battery cell 70 can also have a second current collector plate 79, which is welded to the uncoated section 73 of the second electrode plate. At least one section of the second current collector plate 79, for example a central section 79a thereof, can be welded to the flat section 50d of the electrode terminal 50.

[0191] Preferably, once the second current collector plate 79 is welded, a welding tool can be inserted through the cavity 80 in the core of the electrode assembly 71 to create a weld point on the second current collector plate 79. Furthermore, when the second current collector plate 79 is welded to the flat section 50d of the electrode terminal 50, the weld quality can be improved by applying strong pressure to the weld area, as the electrode terminal 50 supports the weld area of ​​the second current collector plate 79. Additionally, because the flat section 50d of the electrode terminal 50 has a large surface area, a wide weld area can also be ensured. This reduces the contact resistance of the weld area, thereby lowering the internal resistance of the cylindrical battery cell 70.The opposing weld structure of the riveted electrode connection 50 and the second current collector plate 79 is very useful for fast charging using a current with a high C-rate. This is because the current density per unit area in the cross-section can be reduced in the direction of current flow, and thus the amount of heat generated in the current path can be lower than in the prior art.

[0192] When welding the flat section 50d of the electrode connection 50 and the second current collector plate 79, laser welding, ultrasonic welding, spot welding or resistance welding can be used optionally.

[0193] For example, if the flat section 50d and the second current collector plate 79 are laser-welded in a continuous or discontinuous line in the form of an arc pattern, the diameter of the arc weld pattern is 2 mm or more, or 4 mm or more. If the diameter of the arc weld pattern meets the relevant conditions, it is possible to increase the tensile strength of the welded section to 2 kgf or more, thus ensuring sufficient weld strength.

[0194] In another example, if the flat section 50d and the second current collector plate 79 are ultrasonically welded in a circular pattern, the diameter of the circular weld pattern can be 2 mm or more. If the diameter of the circular weld pattern meets the relevant conditions, it is possible to increase the tensile strength of the welded section to 2 kgf or more, thus ensuring sufficient weld strength.

[0195] The diameter of the flat section 50d, which corresponds to the weldable area, can be adjusted from 3 mm to 14 mm. If the radius of the flat section 50d is less than 3 mm, it is difficult to create a weld pattern with a diameter of 2 mm or more using a laser welding tool, an ultrasonic welding tool, or the like. Additionally, if the radius of the flat section 50d exceeds 14 mm, the size of the electrode connection 50 becomes excessively large, and the area occupied by the outer surface 52a of the second end surface 52 of the battery box 51 is reduced, making it difficult to connect an electrical connection component (a busbar) through the outer surface 52a.

[0196] Since preferably the diameter of the weld pattern to ensure the tensile strength of the weld section is 2 kgf or more, and the diameter of the weldable area is 3 mm to 14 mm, the area ratio of the weld pattern to the area of ​​the weldable area can be 2.04 (100·π1 2 / π7 2 ) % to 44.4 (100·π1 2 / π1.5 2 ) %.

[0197] The cylindrical battery cell 70 can further comprise an insulator 80. The insulator 80 can be arranged between the second current collector plate 79 and the inner surface 52a of the second end surface 52 of the battery box 51 and between the inner circumference 51a of the side wall of the battery box 51 and the electrode assembly 71.

[0198] The insulator 80 can have a weld hole 80a that exposes the flat section 50d of the electrode connection 50 towards the second current collector plate 79. Additionally, the weld hole 80a can expose the inner flange section 50c and the inner seal 54b together with the flat section 50d of the electrode connection.

[0199] The insulator 80 can cover the surface of the second current collector plate 79 and an (upper) edge of the electrode assembly 71. This makes it possible to prevent the second current collector plate 79, which has a polarity different from that of the battery box 51, from touching the uncoated section 73 of the second electrode plate.

[0200] The insulator 80 is made of an insulating resin and can comprise a top plate 80b and a side sleeve 80c. In one example, the top plate 80b and the side sleeve 80c can be formed in one piece by injection molding. Alternatively, the side sleeve 80c can be replaced by an insulating tape or the like. The insulating tape can cover the outer edge of the second current collector plate 79 together with the uncoated section 73 of the second electrode plate, which is exposed by the outer circumference of the electrode assembly 71.

[0201] The inner surface 52b of the insulator 80 and the second end surface 52 of the battery box 51 can be in close contact with each other, as shown in Fig. Figure 7b shows this. Here, "close contact" means that there is no visible space (gap). To eliminate the space (gap), the distance from the inner surface 52b of the second end surface 52 of the battery box 51 to the flat section 50d of the electrode terminal 50 can be less than or equal to the thickness of the insulator 80.

[0202] The uncoated sections 72, 73 of the first electrode plate and / or the second electrode plate can be bent in a radial direction, for example from the outer circumference of the electrode assembly 71 to the core, to form curved surfaces on the upper and lower sections of the electrode assembly 71. Additionally, the first current collector plate 78 can be welded to the curved surface formed by bending the uncoated section 72 of the first electrode plate, and the second current collector plate 79 can be welded to the curved surface formed by bending the uncoated section 73 of the second electrode plate.

[0203] To reduce the stress generated when the uncoated sections 72, 73 are bent, the first electrode plate and / or the second electrode plate can have an improved structure that differs from that of the conventional electrode plate (see Fig. 1).

[0204] Fig. Figure 8 is a top view showing an example of the structure of an electrode plate 90.

[0205] With reference to Fig. 8 The electrode plate 90 has a plate-shaped current collector 91 made of a conductive material film, an active mass layer 92 formed on at least one surface of the current collector 91, and an uncoated section 93 formed at a longitudinal side end of the current collector 91 and not coated with an active mass.

[0206] The uncoated section 93 can have several notched segments 93a. The multiple segments 93a form several groups, and the segments 93a contained in each group can have the same height (length in the Y direction) and / or the same width (length in the X direction) and / or the same division. The number of segments 93a belonging to each group can be greater or less than shown. The segment 93a has the shape of a geometric figure in which at least one linear line and / or at least one curve is combined. The segment 93a can have a trapezoidal shape, which can be modified as desired into a rectangular, parallelogram-shaped, semicircular, semi-elliptical shape, or the like.

[0207] The height of segment 93a can be increased stepwise along a direction parallel to the winding direction of the electrode assembly, for example, from the core to the outer circumference. Additionally, a core-side uncoated section 93' adjacent to the core may not include segment 93a, and the height of the core-side uncoated section 93' may be smaller than that of other uncoated section areas. Likewise, an uncoated outer-circumference section 93" adjacent to the outer circumference may not include segment 93a, and the height of the uncoated outer-circumference section 93" may be smaller than that of other uncoated section areas.

[0208] Optionally, the electrode plate 90 can include an insulating coating layer 94 for covering the boundary between the active material layer 92 and the uncoated section 93. The insulating coating layer 94 comprises an insulating polymer resin and can optionally also include an inorganic filler. The insulating coating layer 94 prevents the end of the active material layer 92 from coming into contact with the opposite active material layer of opposite polarity through the separator and serves to structurally support the bending of the segment 93a. For this purpose, if the electrode plate 90 is wound to form an electrode assembly, it may be advantageous for the insulating coating layer 94 to be at least partially exposed to the outside from the separator.

[0209] Fig. Figure 9 is a sectional view of an electrode assembly 100 in which a segment structure is provided along the longitudinal direction (Y) for an uncoated section of the electrode plate 90 at the first electrode plate and the second electrode plate.

[0210] With reference to Fig. 9 the electrode assembly 100 can be by the with reference to Fig. The two described winding methods are used to produce the components. For the sake of simplicity, the above structure of the uncoated sections 72, 73 extending from the separator is shown in detail, while the winding structure of the first electrode plate, the second electrode plate, and the separator is not shown in detail. The uncoated section 72, which projects downwards, extends from the first electrode plate, and the uncoated section 73, which projects upwards, extends from the second electrode plate.

[0211] The pattern in which the heights of the uncoated sections 72, 73 change is shown schematically. Accordingly, the heights of the uncoated sections 72, 73 can vary irregularly depending on the point where the cross-section is cut. For example, if the side section of the trapezoidal segment 93a is cut, the height of the uncoated section at the cross-section is lower than the height of segment 93a. Therefore, it is understood that the heights of the uncoated sections 72, 73 shown in the drawing depicting the cross-section of the electrode assembly 100 correspond to the average heights of the uncoated sections contained in each winding turn.

[0212] The uncoated sections 72, 73 can be bent along the radial direction of the electrode assembly 100, for example from the outer circumference to the core, as shown in the Fig. 10a and Fig. 10b shown. Fig. 9 The curved section 101 is indicated by a dotted line box. When the uncoated sections 72, 73 are curved, curved surfaces 102 are formed on the upper and lower sections of the electrode assembly 100, since the segments that are adjacent to each other in one radius direction overlap each other in multiple layers. At this point, the core-side uncoated section 93' (see Fig. 8) Due to its small height, it is not bent, and the height (h) of the segment bent on the innermost side is less than or equal to the radius direction length (r) of the winding area formed by the core-side uncoated section 93' without a segment structure. Therefore, the cavity 80 in the core of the electrode assembly 100 is not closed off by the bent segments. Since the cavity 80 is not closed off, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, the electrode terminal 50 and the second current collector plate 79 can be easily welded by inserting a welding tool through the cavity 80.

[0213] In the cylindrical battery cell 70 according to the embodiment of the present disclosure, the cover plate 74a of the sealing body 74 has no polarity. Instead, the first current collector plate 78 is connected to the side wall of the battery box 51, such that the outer surface 52a of the second end surface 52 of the battery box 51 has an opposite polarity to the electrode terminal 50. Therefore, if a plurality of cells are to be connected in series and / or parallel, wiring similar to a busbar connection can be carried out on the upper section of the cylindrical battery cell 70 using the electrode terminal 50 and the outer surface 52a of the second end surface 52 of the battery box 51. This allows the energy density to be improved by increasing the number of cells that can be mounted in the same space, and the electrical wiring work can be carried out simply.

[0214] Fig. Figure 11 is a diagram showing a state in which the cylindrical battery cells 70 are electrically connected using a busbar 150.

[0215] With reference to Fig. 11. The multiple cylindrical battery cells 70 can be connected in series and parallel on an upper section using the busbar 150. The number of cylindrical battery cells 70 can be increased or decreased depending on the capacity of the battery pack.

[0216] In each cylindrical battery cell 70, the electrode terminal 50 can have a positive polarity and the outer surface 52a of the second end surface 52 of the battery box 51 can have a negative polarity, and vice versa.

[0217] The multitude of cylindrical battery cells 70 can be arranged in a multitude of columns and rows. Columns are arranged in an upper and lower direction with respect to the ground, and rows are arranged in a left and right direction with respect to the ground. To maximize space efficiency, the cylindrical battery cells 70 can also be arranged in a very dense packing structure. The densest packing structure is formed when the centers of the electrode terminals 50 form an equilateral triangle when connected to one another.

[0218] The busbar 150 can be arranged above the multitude of battery cells, in particular between adjacent columns. Alternatively, the busbar 150 can be arranged between adjacent rows.

[0219] The busbar 150 connects cells that are arranged parallel to each other in the same column, and connects cells that are arranged in two adjacent columns in a row.

[0220] Preferably, the busbar 150 for series and parallel connection can have a body section 151, a plurality of first busbar connections 152 and a plurality of second busbar connections 153.

[0221] The body section 151 can extend between electrode terminals (50) of adjacent cylindrical battery cells 70, in particular between gaps of the cylindrical battery cells 70. Alternatively, the body section 151 can extend along a gap of cylindrical battery cells 70 and can be regularly curved in a zigzag shape.

[0222] The plurality of first busbar terminals 152 can project from one side of the body section 151 towards the electrode terminal 50 of each cylindrical battery cell 70 and can be electrically coupled to the electrode terminal 50. The electrical coupling to the electrode terminal 50 can be achieved by laser welding, ultrasonic welding, or the like. Additionally, the plurality of second busbar terminals 153 can project from the other side of the body section 151 towards the outer surface 52a of the second end surface 52 of the battery housing 51 of each cylindrical battery cell 70 and can be electrically coupled to the outer surface 52a. The electrical coupling to the outer surface 52a can be carried out by laser welding, ultrasonic welding, or the like.

[0223] The body section 151, the plurality of first busbar connections 152, and the plurality of second busbar connections 153 can be formed from a single conductive metal plate. The metal plate can be an aluminum plate or a copper plate, but the present disclosure is not limited to these. In a modified example, the body section 151, the plurality of first busbar connections 152, and the plurality of second busbar connections 153 can be manufactured as separate pieces and then coupled together by welding or the like.

[0224] In the cylindrical battery cell 70 according to the present disclosure, the electrode terminal 50 with a positive polarity and the outer surface 52a of the second end surface 52 of the battery box 51 with a negative polarity are aligned in the same direction, and thus the cylindrical battery cells 70 can be easily electrically connected using the busbar 150.

[0225] Furthermore, since the electrode connection 50 and the outer surface 52a of the cylindrical battery cell 70 have a large area, the coupling surface of the busbar 150 can be sufficiently secured to adequately reduce the resistance of the battery pack including the cylindrical battery cell 70.

[0226] Fig. Figure 12a is a partially enlarged view showing an electrical connection section between the busbar 150 and the cylindrical battery cell 70, and the Fig. 12b and Fig. Figure 12c schematically shows the definition of various parameters in order to design upper and lower limits of the diameter of the electrode connection 50 and the exposure width of the outer surface 52a, taking into account the sizes of the busbar connections 152, 153.

[0227] With reference to the Fig. 12a, Fig. 12b and Fig. 12c the diameter (E1) of the electrode connection 50 and the width (E2) of the annular outer surface 52a can be adaptively adjusted in the cylindrical battery cell 70, taking into account the dimensions of the contact surfaces of the busbar connections 152, 153.

[0228] Here, the width E2 of the outer surface 52a is the width of the exposed area parallel to the surface of the electrode terminal 50. Specifically, the width E2 of the outer surface 52a is defined as the width of a line segment connecting two points where a linear line (L1), drawn radially from the center C of the electrode terminal 50, intersects the inner and outer boundaries of the outer surface 52a. The width E2 of the outer surface 52a is the width of the flat exposed area, excluding the rounded area present at the edge of the second end surface 52 and the exposed area 54a' of the outer seal 54a.

[0229] The outer surface of the second end surface 52 of the battery box 51 can be subdivided, when viewed from above, into the electrode connection 50, the exposed area 54a' of the seal 54, and the round area R at the edge of the outer surface 52a. The round area R is a processing area (see Fig. 7a and Fig. 7b) for smoothly connecting the second end surface 52 of the battery box 51 and the side wall of the battery box 51 and has a width (R d ) on one level.

[0230] The first busbar connection 152 of the busbar 150 branches off to a side that differs from the direction of movement of the body section 151 and is electrically coupled to the electrode connection 50. At this point, the electrode connection 50 and the first busbar connection 152 form a first overlap region (hatched in the drawing) on ​​one plane, and the first overlap region has a first width (W1). Here, the first overlap region is an area where the electrode connection 50 and the first busbar connection 152 overlap on one plane.

[0231] The first width (W1) is defined as a maximum value among the distances between any two points selected within the boundary of the first overlap region. The definition of the first width (W1) is applied identically when the first overlap region has the center of electrode terminal 50 ( Fig. 12b) and if the first overlap area does not have the center of the electrode connection 50 ( Fig. 12c). With reference to the Fig. 12b and Fig. 12c corresponds to the distance represented by W1 being a maximum value among the distances between any two points selected in the boundary of the first overlap area.

[0232] The second busbar connection 153 of the busbar 150 extends in a direction opposite to the first busbar connection 152, based on the direction of movement of the body section 151, and is electrically coupled to the outer surface 52a of the second end surface 52 of the battery box 51. At this point, the second busbar connection 153 and the outer surface 52a form a second overlap region (hatched in the figure) on one plane, and the second overlap region has a second width (W2). Here, the second overlap region is an area where the outer surface 52a and the second busbar connection 153 overlap on one plane.

[0233] The second width (W2) is defined as a maximum value among the widths between two points where each linear line and the edge of the second overlap area meet when multiple linear lines (L3) are drawn from the center C of electrode terminal 50 to pass through the second overlap area.

[0234] The diameter (E1) of the electrode terminal 50 must be at least equal to or greater than the first width (W1) of the first busbar terminal 152. This is because the first overlap area of ​​the first busbar terminal 152 and the electrode terminal 50 must not deviate from the electrode terminal 50 on the same plane. Furthermore, the diameter (E1) of the electrode terminal 50 can be increased to the maximum until the distance between the boundary of the electrode terminal 50 and the second busbar terminal 153 corresponds to the width (G) of the exposed area 54a' of the outer seal 54a. Therefore, the maximum value of the diameter (E1) of the electrode terminal 50 is D-2R. d -2*G-2* W2'.

[0235] The width (E2) of the outer surface 52a is a factor that depends on the diameter (E1) of the electrode terminal 50 and should be at least equal to or greater than the second width (W2) of the second busbar terminal 153. Only in this case can an overlap area of ​​the second busbar terminal 153 and the outer surface 52a be formed. Additionally, the width (E2) of the outer surface 52a can be increased to a maximum of 50% of 'D-2* R'. d -2*G- E1' is increased, which is a value obtained by subtracting the diameter (E1) of the electrode connection 50, the width (2*G) of the exposed area of ​​the outer seal 54a and the width (2* R a ) of the round area is obtained from the outer diameter (D) of the battery box 51.

[0236] In summary, for the cylindrical battery cell 70 according to the present disclosure, it may be advantageous that the diameter (E1) of the electrode terminal 50 and the width (E2) of the outer surface 52a are designed to satisfy the following relational expression. W1≤E1≤D−2Rd−2G−2W2 E2=0.5*(D−2Rd−2G−E1)

[0237] (E1: Diameter of electrode connection 50, E2: Width of outer surface 52a, D: Outer diameter of battery box 51, R d : Width of the round area R measured on a plane, G: Width of the exposed area 54a' of the outer seal 54a, W1: Width of the first busbar connection 152, W2: Width of the second busbar connection 153)

[0238] In a specific example, if D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm and R is 1 mm, the diameter (E1) of the electrode connection 50 is 6 mm to 31 mm and the width (E2) of the outer surface 52a is 6 mm to 18.5 mm.

[0239] According to another example, the diameter (E1) of the electrode connection 50 is 6 mm to 30 mm and the width (E2) of the outer surface 52a is 6 mm to 18 mm, if D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm and R d 1.5 mm.

[0240] As described above, the cylindrical battery cell 70 of the present disclosure has a structure in which the resistance is minimized by extending a welded area through a curved surface of the uncoated section, multiplexing a current path using a first current collector plate, minimizing a current path length, and the like. The AC resistance of the cylindrical battery cell 70, measured using a resistance measuring instrument between the electrode terminal 50 (positive polarity terminal) and the outer surface 52a (negative polarity terminal) near the electrode terminal 50, can be about 4 milliohms (mΩ) or less, which is suitable for fast charging. The resistance can be 0.5 mΩ or more, or 1.0 mΩ or more.

[0241] In the present disclosure, an active material of the positive electrode, which is applied to the positive electrode plate, and an active material of the negative electrode, which is applied to the negative electrode plate, can use any active material known from the prior art without restriction.

[0242] In one example, the active mass of the positive electrode can comprise an alkali metal compound, which can be described by a general formula A[A x M y ]O 2+z is expressed (A includes at least one element from Li, Na and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru and Cr; x ≥ 0, 1 ≤ x + y ≤ 2, 0,1 ≤ z ≤ 2; and the stoichiometric coefficients x, y and z are selected such that the compound retains electrical neutrality).

[0243] According to another example, the active material of the positive electrode can be an alkali metal compound xLiM. 1 O2(1x)Li2M 2 O3, which is disclosed in US6,677,082, US6,680,143, et al., wherein M1 comprises at least one element with an average oxidation state of 3; M2 comprises at least one element with an average oxidation state of 4; and 0 ≤ x ≤ 1).

[0244] In yet another example, the active mass of the positive electrode can be lithium metal phosphate, which can be described by the general formula Li a M 1 x Fddd x M 2 y P 1y M 3 z O 4z is expressed (M 1 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2 includes 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 3comprises a halogen element, optionally including F; 0 a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y 1, 0 ≤ z 1; the stoichiometric coefficients a, x, y and z are selected such that the compound retains electrical neutrality), or Li3M2(PO4)3 (M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al).

[0245] The active mass of the positive electrode can contain primary particles and / or secondary particles in which the primary particles are aggregated.

[0246] In one example, the active material of the negative electrode can be carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, or the like. Metal oxides such as TiO₂ and SNO₂ with a potential of less than 2 V can also be used as the active material of the negative electrode. Low-crystalline and / or high-crystalline carbon can be used as the carbon material.

[0247] The separator can use a porous polymer film, for example, a porous polymer film made from a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, or the like, or laminates thereof. Alternatively, the separator can use a common porous nonwoven fabric, for example, a nonwoven fabric made from high-melting-point glass fiber, polyethylene terephthalate fiber, or the like.

[0248] A coating layer of inorganic particles can be present on at least one surface of the separator. It is also possible that the separator itself is made from a coating layer of inorganic particles. Particles in the coating layer can be bonded with a binder, resulting in an interstitial volume between adjacent particles.

[0249] The inorganic particles can be made from an inorganic material with a dielectric constant of 5 or higher. As a non-restrictive example, the inorganic particles can comprise at least one material selected from the group consisting of Pb(Zr,Ti)O3 (PZT), Pb 1x La x Zr 1y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMNPT), BaTiO3, Hafnium oxide ((HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO or Y2O3.

[0250] The electrolyte can be a salt with a structure like A+B-. Here, A+ comprises an alkali metal cation such as Li. + , N / a + , or K + or a combination thereof and B- comprises at least one anion selected from the group consisting of 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 - consists.

[0251] The electrolyte can also be dissolved in an organic solvent. The organic solvent can 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.

[0252] The cylindrical battery cell 70 according to the above embodiment can be used to manufacture a battery pack.

[0253] Fig. Figure 13 is a diagram that schematically shows a battery pack.

[0254] With reference to Fig. Figure 13 includes a battery pack 200, a unit in which cylindrical battery cells 201 are electrically connected, and a pack housing 202 for accommodating the unit. The cylindrical battery cell 201 is the battery cell according to the embodiment described above. For the sake of simplicity, components such as a busbar, a cooling unit, and an external connection for the electrical connection of the cylindrical battery cells 201 are not shown in the drawing.

[0255] The 200-unit battery pack can be mounted on a vehicle. The vehicle can be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid vehicle. The vehicle can be a four-wheeled vehicle or a two-wheeled vehicle.

[0256] Fig. Figure 14 is a diagram illustrating a vehicle with the 200 battery pack. Fig. 13.

[0257] With reference to Fig. 14. A vehicle V includes the battery pack 200. The vehicle V operates by receiving power from the battery pack 200.

[0258] The present disclosure has been described in detail. However, it is understood that the detailed description and specific examples serve only for illustration, since various changes and modifications within the scope of the disclosure will be apparent to those skilled in the art from this detailed description.

[0259] In light of the above, it is understood that the present invention also relates to the following detailed embodiments: ITEM 1. Having a rivet structure of an electrode connection: a battery box designed to have one open side; an electrode connection that is riveted through a perforated opening formed in the base of the battery box; and a rivet seal arranged between the electrode connection and the perforation opening, the electrode connection has: a body part that is inserted into the perforation opening; an outer flange section designed to extend along an outer surface of the bottom of the battery box from a circumference of one side of the body section exposed by the outer surface; an inner flange section designed to extend from a circumference exposed through the inner surface of the other side of the body section to an inner surface of the bottom of the battery box; and a flat section provided on an inside side of the inner flange section. ITEM 2. Rivet structure of an electrode connection according to Item 1, wherein the flat section is parallel to the inner surface of the base. ITEM 3. Rivet structure of an electrode connection according to one of items 1 and 2, wherein an angle between the inner flange section and the inner surface of the base is 0° to 60°. ITEM 4. Rivet structure of an electrode connection according to one of items 1 to 3, wherein a recess is provided between the inner flange section and the flat section. ITEM 5. Rivet structure of an electrode connection according to one of items 1 to 4, wherein the recess has a cross-sectional structure of an asymmetrical groove. ITEM 6. Rivet structure of an electrode connection according to one of items 1 to 5, wherein the asymmetrical groove has a side wall of the flat section and an inclined surface of the inner flange section connected to an end of the side wall. ITEM 7. Rivet structure of an electrode connection according to one of items 1 to 6, wherein the side wall is perpendicular to the inner surface of the base. ITEM 8. Rivet structure of an electrode connection according to one of items 1 to 6, wherein the side wall is inclined towards the flat section. ITEM 9. Rivet structure of an electrode connection according to one of items 1 to 10, wherein the inner flange section has a thickness that gradually decreases with increasing distance from the body section. ITEM 10. Rivet structure of an electrode connection according to one of items 1 to 11, wherein the rivet seal comprises: an outer seal arranged between the outer flange section and the outer surface of the base and an inner seal arranged between the inner flange section and the inner surface of the base, wherein the inner seal has different thicknesses depending on location. ITEM 11. Rivet structure of an electrode connection according to any of items 1 to 10, wherein an area of ​​the inner seal arranged between an inner edge of the perforation opening connected to the inner surface of the base and the inner flange section has a relatively smaller thickness than the other area. ITEM 12. Rivet structure of an electrode connection according to one of items 1 to 11, wherein an area of ​​the inner seal arranged between the perforation opening and the body section has a thickness that gradually decreases with increasing distance from the outer flange section. ITEM 13. Rivet structure of an electrode connection according to one of items 1 to 12, wherein a region of the inner seal arranged between the inner surface of the base and a region near an end of the inner flange section has a minimum thickness. ITEM 14. Rivet structure of an electrode connection according to one of items 1 to 13, wherein the inner edge of the perforation opening comprises a facing surface that is facing the inner flange section. ITEM 15. Rivet structure of an electrode connection according to any of items 1 to 14, wherein the inner seal is designed to extend longer than the inner flange section, leaving one end exposed. ITEM 16. Rivet structure of an electrode connection according to any of items 1 to 15, wherein a height of the flat section based on the inner surface of the base is greater than or equal to a height of an end of the inner seal. ITEM 17. Rivet structure of an electrode connection according to one of items 1 to 16, wherein a height of the flat section based on the inner surface of the bottom is greater than or equal to a height of the inner flange section. ITEM 18. Rivet structure of an electrode connection according to one of items 1 to 17, wherein a height of the inner flange section based on the inner surface of the bottom is greater than a height of an end of the inner seal. ITEM 19. Rivet structure of an electrode connection according to one of items 1 to 18, wherein the height of the inner flange section based on the inner surface of the bottom of the battery box is 0.5 mm to 3.0 mm. ITEM 20. Rivet structure of an electrode connection according to one of items 1 to 19, wherein the height of the electrode connection extending from a lower surface of the outer flange section to a surface of the flat section is 4 mm to 7 mm. ITEM 21. Rivet structure of an electrode connection according to any of items 1 to 20, wherein the height of the outer flange section based on the outer surface of the bottom of the battery box is 0.8 mm or more. ITEM 22. Rivet structure of an electrode connection according to any of items 1 to 21, wherein at least a section of the outer seal is exposed to the outside of the outer flange section and the exposure width of the outer seal, measured in a direction parallel to the outer surface of the bottom of the battery box, is 0.1 mm to 1 mm. ITEM 23. Rivet structure of an electrode connection according to one of items 1 to 22, wherein a radius from a center of the body section to an edge of the outer flange section is 10% to 70% of a radius of the base of the battery box. ITEM 24. Rivet structure of an electrode connection according to one of items 1 to 23, wherein a radius from a center of the body section to an edge of the flat section is 4% to 30% of a radius of the base. ITEM 25. Rivet structure of an electrode connection according to any of items 1 to 24, wherein, if a ratio of the thickness change at a maximum compression point compared to a thickness before compression of the seal is defined as a compression ratio, the compression ratio of the inner seal is 30% to 90%. ITEM 26. Rivet structure of an electrode connection according to one of items 1 to 25, wherein the inner seal comprises polybutylene terephthalate, polyethylene fluoride or polypropylene and the compression ratio of the inner seal is 50% to 90%. ITEM 27. Featuring a cylindrical battery cell: an electrode assembly in which a first electrode plate and a second electrode plate are wound in a sheet shape with a separator arranged between them, the electrode assembly having an uncoated section of the first electrode plate and an uncoated section of the second electrode plate designed to extend from both ends thereof and expose outside the separator; a cylindrical battery box designed to accommodate the electrode assembly and to be electrically connected to the first electrode plate; an electrode connection which is riveted through a perforation opening formed in the base of the battery box and electrically connected to the second electrode plate; the electrode connection has: a body part that is inserted into the perforation opening; an outer flange section designed to extend along an outer surface of the bottom of the battery box from a circumference of one side of the body section exposed by the outer surface; an inner flange section designed to extend from a circumference exposed through the inner surface of the other side of the body section to an inner surface of the bottom of the battery box; and a flat section provided on an inside side of the inner flange section, a rivet seal arranged between the electrode connection and the perforation opening; and a sealing body designed to seal an open end of the battery box in order to be isolated from the battery box. ITEM 28. Cylindrical battery cell according to one of Item 27, wherein the battery box has a beaded section formed in an area adjacent to the open end and pressed into the battery box, and the sealing body has a non-polarizing cover plate and a seal arranged between an edge of the cover plate and the open end of the battery box. ITEM 29. Cylindrical battery cell according to one of items 27 and 28, wherein the battery box further comprises a crimp section extending into the interior of the battery box and is bent and configured to surround and secure the edge of the cover plate together with the gasket. ITEM 30. Cylindrical battery cell according to any of items 27 to 29, wherein the cover plate has a vent notch which breaks open when pressure inside the battery can exceeds a threshold. ITEM 31. Cylindrical battery cell according to one of items 27 to 30, wherein the vent notch is broken when the pressure inside the battery can is in the range of 15 kgf / cm² 2 up to 35 kgf / cm² 2 lies. ITEM 32. Cylindrical battery cell according to any one of items 27 to 31, further comprising: a first current collector plate coupled to the uncoated section of the first electrode plate, wherein at least a part of an edge of the first current collector plate, which is not in contact with the uncoated section of the first electrode plate, is arranged between the bead section and the seal and is fixed by the crimp section. ITEM 33. Cylindrical battery cell according to any one of items 27 to 32, wherein at least a part of the edge of the first current collector plate is fixed by welding to an inner circumference of the bead section adjacent to the crimp section. ITEM 34. Cylindrical battery cell according to any one of items 27 to 33, further comprising: a second current collector plate coupled to the uncoated section of the second electrode plate, wherein at least a part of the second current collector plate is coupled to the flat section of the electrode terminal. ITEM 35. Cylindrical battery cell according to any of items 27 to 34, wherein the second current collector plate and the flat section of the electrode terminal are coupled by welding and the tensile force of the welded section between the second current collector plate and the flat section of the electrode terminal is 2 kgf or more. ITEM 36. Cylindrical battery cell according to any of items 27 to 35, wherein a converted diameter of the weld pattern exposed on a surface of the second current collector plate is 2 mm or more. ITEM 37. Cylindrical battery cell according to any of items 127 to 36, wherein the diameter of the flat section of the electrode terminal is 3 mm to 14 mm. ITEM 38. Cylindrical battery cell according to any one of items 27 to 37, wherein the ratio of an area of ​​the weld pattern exposed on a surface of the second current collector plate to an area of ​​the flat section of the electrode terminal is 2.04% to 44.4%. ITEM 39. Cylindrical battery cell according to any one of items 27 to 38, further comprising: an insulator arranged between the second current collector plate and an inner circumference of the bottom of the battery box and between an inner circumference of a side wall of the battery box and the electrode assembly. ITEM 40. Cylindrical battery cell according to any of items 27 to 39, wherein the insulator has a weld hole designed to expose the flat section of the electrode terminal towards the second current collector plate and covering a surface of the second current collector plate and an edge of one side of the electrode assembly. ITEM 41. Cylindrical battery cell according to any of items 27 to 40, wherein a height from the inner surface of the bottom of the battery box to the flat section of the electrode terminal is less than or equal to the thickness of the insulator. ITEM 42. Cylindrical battery cell according to any one of Items 27 to 41, wherein the rivet seal comprises: an outer seal arranged between the outer flange section and the outer surface of the bottom of the battery box; and an inner seal arranged between the inner flange section and the inner surface of the bottom of the battery box. ITEM 43. Cylindrical battery cell according to any of items 27 to 42, wherein one end of the inner seal is exposed to the outside of the inner flange section. ITEM 44. Cylindrical battery cell according to any of items 27 to 43, wherein the weld hole exposes the flat section of the electrode terminal and the inner flange section. ITEM 45. Cylindrical battery cell according to any of items 27 to 44, wherein the weld hole exposes the flat section of the electrode terminal, the inner flange section and the inner seal. ITEM 46. Cylindrical battery cell according to one of items 27 to 45, wherein a first busbar terminal is electrically coupled to a surface of the electrode terminal and a second busbar terminal is electrically coupled to the outer surface of the bottom of the battery box. ITEM 47. Cylindrical battery cell according to any of items 27 to 46, wherein the first busbar terminal overlaps the electrode terminal on one plane to form a first overlap area, and the second busbar terminal overlaps the outer surface of the bottom of the battery box to form a second overlap area, and an electrode terminal diameter and outer surface width W1≤E1≤D−2Rd−2G−2W2 E2=0.5*(D−2Rd−2G−E1) The base of the battery box must satisfy the following relational expression, E1: diameter of the electrode connection, E2: width of an exposed area parallel to an area of ​​the electrode connection in the outer surface of the base of the battery box, D: outer diameter of the battery box, R d: Width of a circular area at an edge of the battery box, measured on a plane, G: Exposure width of the outer seal by an edge of the electrode terminal, W1: Maximum value among distances between any two points selected in an edge of the first overlap area, W2: Maximum value among distances between two points where a plurality of linear lines passing through the center of the electrode terminal meet an edge of the second overlap area. ITEM 48. Cylindrical battery cell according to any of points 27 to 47, wherein a form factor ratio obtained by dividing a diameter of the cylindrical battery cell by its height is greater than 0.4. ITEM 49. Battery pack comprising a plurality of cylindrical battery cells according to any one of claims 27 to 48. ITEM 50. Battery pack according to Item 49, wherein the plurality of cylindrical battery cells is arranged in a predetermined number of columns and the electrode terminal and the outer surface of the bottom of the battery box of each cylindrical battery cell are arranged to face upwards. ITEM 51. Battery pack according to one of claims 49 and 50, further comprising: a multitude of busbars configured to connect the multitude of cylindrical battery cells in series and parallel, wherein the multitude of busbars is arranged above the multitude of cylindrical battery cells, where each busbar has: a body section designed to extend between the electrode terminals of adjacent cylindrical battery cells; a plurality of first busbar connections, each designed to extend in one lateral direction from the body section and electrically coupled to the electrode terminal of the cylindrical battery cell located in one lateral direction; and a multitude of second busbar connections, each designed to extend in the opposite lateral direction from the body section and electrically coupled to the outer surface of the bottom of the battery box of the cylindrical battery cell, which is located in the opposite lateral direction. ITEM 52. Battery pack according to any one of claims 49 to 51, wherein the AC resistance of the cylindrical battery cell, measured between the electrode terminal and the outer surface of the bottom of the battery box, is 4 milliohms (mΩ) or less. ITEM 53. Vehicle comprising at least one battery pack according to any one of claims 49 to 52. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 6,677,082

[0243] US 6,680,143

[0243]

Claims

[1] Cylindrical battery cell (70) comprising: an electrode arrangement (71) comprising a first electrode plate, a second electrode plate and a separator arranged between them, wherein the electrode arrangement (71) is wound such that it has a first end face and a second end face (52) opposite each other, wherein the first electrode plate has an uncoated section arranged at the first end face of the electrode arrangement (71) and the second electrode plate has an uncoated section arranged at the second end face (52) of the electrode arrangement (71), wherein the uncoated sections extend beyond the separator; a battery box (51) which accommodates the electrode arrangement (71) and is electrically connected to the first electrode plate, wherein the battery box (51) has a first end face and a second end face (52) which are opposite each other, wherein the first end face is open; an electrode connection (50, 50') which passes through a perforated opening (53) formed in the second end face (52) of the battery box (51); and a sealing body (74) that closes the first end face of the battery box (51); a seal (54) which is arranged between the electrode connection (50, 50') and the perforation opening (53), where the electrode connection has (50, 50'): - a body segment (50a) that passes through the perforation opening (53); - an outer flange section (50b) extending from the body section (50a) along an outer surface (52a) of the second end surface (52) of the battery box (51); - an inner flange section (50c) arranged inside the battery box (51) and extending outwards from the body section (50a); and - a flat section (50d) arranged in the battery box (51) and surrounded by the inner flange section (50c), wherein a recess is formed between the inner flange section (50c) and the flat section (50d); wherein the seal (54) has: an outer seal (54a) arranged between the outer flange section (50b) and the outer surface (52a) of the second end surface (52) of the battery box (51); and an inner seal (54b) arranged between the inner flange section (50c) and the inner surface (52b) of the second end surface (52) of the battery box (51), wherein at least one section (54a') of the outer seal (54a) is exposed to the outside of the outer flange section (50b) of the electrode connection (50), wherein the exposure width (G) of the outer seal (54a), measured in a direction parallel to the outer surface of the second end surface (52) of the battery box (51), is 0.1 mm to 1 mm. [2] Cylindrical battery cell (70) according to claim 1, wherein the flat section (50d) is parallel to an inner surface (52b) of the second end surface (52) of the battery box (51). [3] Cylindrical battery cell (70) according to claim 1 or 2, wherein an angle (θ) between the inner flange section (50c) and the inner surface (52b) of the second end surface (52) is 0° to 60°, preferably 2° to 60°. [4] Cylindrical battery cell (70) according to one of the preceding claims, wherein the side wall (55a) of the body section (50a) is perpendicular to the inner surface of the second end surface (52) of the battery box (51). [5] Cylindrical battery cell (70) according to one of the preceding claims, wherein the inner flange section (50c) has a thickness that decreases with increasing distance from the body section (50a). [6] Cylindrical battery cell (70) according to one of the preceding claims, wherein the thickness of the inner seal (54b) varies in an outward direction. [7] Cylindrical battery cell (70) according to claim 6, wherein a thickness of the inner seal (54b) between an edge of the perforation opening (53) and the inner flange section (50c) is less than a thickness of a remainder of the inner seal (54b). [8] Cylindrical battery cell (70) according to claim 6 or 7, wherein a region of the inner seal (54b) arranged between the perforation opening (53) and the body section (50a) has a thickness that decreases with increasing distance from the outer flange section (50b). [9] Cylindrical battery cell (70) according to any one of claims 6 to 8, wherein the thickness of the inner seal (54b) is minimal at one end of the inner flange section (50c). [10] Cylindrical battery cell (70) according to one of claims 6 to 9, wherein the edge of the perforation opening (53) has a surface facing the inner flange section (50c). [11] Cylindrical battery cell (70) according to any one of claims 6 to 9, wherein the inner seal (54b) extends further from the body section (50a) than the inner flange section (50c), so that an end section of the inner seal (54b) is exposed. [12] Cylindrical battery cell (70) according to any one of claims 6 to 11, wherein a distance (H1) of the flat section (50d) from the inner surface (52b) of the second end surface (52) of the battery box (51) is equal to or greater than a height (H2) of an end of the inner seal (54b) from the inner surface (52b) of the second end surface (52) of the battery box (51). [13] Cylindrical battery cell (70) according to one of the preceding claims, wherein a height (H1) of the flat section (50d) is equal to or greater than a height (H3) of the inner flange section (50c), wherein the heights (H1, H3) are measured from the inner surface (52b) of the second end surface (52) of the battery box (51). [14] Cylindrical battery cell (70) according to any one of claims 6 to 13, wherein a height (H3) of the inner flange section (50c) is greater than a height (H2) of an end of the inner seal (54b), wherein the heights (H2, H3) are measured from the inner surface (52b) of the second end surface (52) of the battery box (51). [15] Cylindrical battery cell (70) according to one of the preceding claims, wherein a height (H3) of the inner flange section (50c) is 0.5 mm to 3.0 mm from the inner surface (52b) of the second end surface (52) of the battery box (51). [16] Cylindrical battery cell (70) according to one of the preceding claims, wherein a height (H4) of the electrode connection (50, 50') between an outer surface (52a) of the outer flange section (50b) and a surface of the flat section (50d) is 4 mm to 7 mm. [17] Cylindrical battery cell (70) according to one of the preceding claims, wherein a height (H5) of the outer flange section (50b) is 0.8 mm or more from the outer surface (52a) of the second end surface (52) of the battery box (51). [18] Cylindrical battery cell (70) according to any one of claims 6 to 17, wherein a radius (R1) from a center of the body section (50a) to an edge of the outer flange section (50b) is 10% to 70% of a radius (R2) of the second end face (52) of the battery box (51). [19] Cylindrical battery cell (70) according to one of the preceding claims, wherein a radius (R3) of the flat section (50d) is 4% to 30% of a radius (R2) of the second end surface (52) of the battery box (51). [20] Cylindrical battery cell (70) according to any one of claims 6 to 19, wherein, if a ratio of the thickness change at a maximum compression point compared to a thickness before compression of the seal (54) is defined as a compression ratio, the compression ratio of the inner seal (54b) is 30% to 90% or 50% to 90%. [21] Cylindrical battery cell (70) according to any one of claims 6 to 20, wherein the inner seal (54b) comprises polybutylene terephthalate, polyethylene fluoride or polypropylene. [22] Cylindrical battery cell (70) according to any one of claims 1 to 21, wherein the battery box (51) has a bead section (76) which is formed by pressing a side wall (55a) of the battery box (51) inwards at a position proximal to the first end face of the battery box (51), and wherein the sealing body (74) has a cover plate (74a) and a seal (74b) which is arranged between the cover plate (74a) and the first end face of the battery box (51). [23] Cylindrical battery cell (70) according to claim 22, wherein the battery box (51) further comprises a crimp section (75) which extends into the interior of the battery box (51) and is bent and configured to surround and fix the edge of the cover plate (74a) together with the seal (74b). [24] Cylindrical battery cell (70) according to claim 22 or 23, wherein the cover plate (74a) has a vent notch (77) configured to break when a pressure inside the battery can (51) exceeds a threshold. [25] Cylindrical battery cell (70) according to claim 24, wherein the threshold value is in a range of 1471 kPa (15 kgf / cm²). 2 ) up to 3432 kPa (35 kgf / cm²) 2 ) lies. [26] Cylindrical battery cell (70) according to one of claims 1 to 25, further comprising: a first current collector plate (78) coupled to the uncoated section (72) of the first electrode plate, wherein the first current collector plate (78) is electrically connected between the first electrode plate (11a) and the battery box. [27] Cylindrical battery cell (70) according to one of claims 22 to 25, further comprising: a first current collector plate (78) coupled to the uncoated section of the first electrode plate, wherein at least one edge part (78a) of the first current collector plate (78) is not in physical contact with the uncoated section of the first electrode plate, is arranged between the bead section (76) and the seal (74b) and is fixed by the crimp section (75). [28] Cylindrical battery cell (70) according to claim 27, wherein at least one edge part (78a) of the first current collector plate (78) is fixed by welding to an inner surface (52b) of the bead section (76) adjacent to the crimp section (75). [29] Cylindrical battery cell (70) according to any one of claims 1 to 28, further comprising: a second current collector plate (79) coupled to the uncoated section of the second electrode plate, wherein at least a part (79a) of the second current collector plate (79) is coupled to the flat section (50d) of the electrode connection (50, 50'). [30] Cylindrical battery cell (70) according to claim 29, wherein the second current collector plate (79) and the flat section (50d) of the electrode connection (50, 50') are coupled together by welding, and wherein the second current collector plate (79) and the flat section (50d) of the electrode connection (50, 50') are welded to give a tensile strength of 19.6 N (2 kgf) or more. [31] Cylindrical battery cell (70) according to claim 30, wherein an equivalent diameter of a weld pattern exposed on a surface of the second current collector plate (79) is 2 mm or more. [32] Cylindrical battery cell (70) according to any one of claims 1 to 31, wherein the diameter of the flat section (50d) of the electrode connection (50, 50') is 3 mm to 14 mm. [33] Cylindrical battery cell (70) according to one of claims 29 to 32, wherein the ratio of an area of ​​a weld pattern exposed on a surface of the second current collector plate (79) to an area of ​​the flat section (50d) of the electrode connection (50, 50') is 2.04% to 44.4%. [34] Cylindrical battery cell (70) according to one of claims 29 to 33, further comprising: an insulator (80) arranged between the second current collector plate (79) and an inner surface (52b) of the second end surface (52) of the battery box (51) and between an inner circumference (51a) of a side wall (55a) of the battery box (51) and the electrode arrangement (71). [35] Cylindrical battery cell (70) according to claim 34, wherein the insulator (80) has a weld hole (80a) which is designed to expose the flat section (50d) of the electrode connection (50, 50') opposite the second current collector plate (79), and wherein the insulator (80) covers the second current collector plate (79) and an edge of the second end face (52) of the electrode arrangement (71). [36] Cylindrical battery cell (70) according to claim 34 or 35, wherein a height (H1) of the flat section (50d) of the electrode terminal (50, 50') from the inner surface (52b) of the second end surface (52) of the battery box (51) is equal to or less than a thickness of the insulator (80). [37] Cylindrical battery cell (70) according to one of claims 1 to 36, wherein the seal (54) comprises: an outer seal (54a) arranged between the outer flange section (50b) and the outer surface (52a) of the second end surface (52) of the battery box (51); and an inner seal (54b) arranged between the inner flange section (50c) and the inner surface (52b) of the second end surface (52) of the battery box (51). [38] Cylindrical battery cell (70) according to claim 37, wherein one end of the inner seal (54b) is exposed to the outside of the inner flange section (50c). [39] Cylindrical battery cell (70) according to claim 35, wherein the weld opening (80a) exposes the flat section (50d) of the electrode connection (50, 50') and the inner flange section (50c). [40] Cylindrical battery cell (70) according to claim 39, wherein the weld opening (80a) further exposes the inner seal (54b). [41] Cylindrical battery cell (70) according to any one of claims 1 to 40, further comprising: a first busbar connection (152) which is electrically coupled to the electrode connection (50, 50'); and a second busbar connection (153) which is electrically coupled to the outer surface (52a) of the second end surface (52) of the battery box (51). [42] Cylindrical battery cell (70) according to claim 41, wherein the first busbar terminal (152) lies on the electrode terminal (50, 50') to form a first overlap area, and the second busbar terminal (153) lies on the outer surface (52a) of the second end surface (52) of the battery box (51) to form a second overlap area, and wherein a diameter of the electrode connection (50, 50') and a width of the outer surface (52a) of the second end surface (52) of the battery box (51) satisfy the following relation expression, W1≤E1≤D−2Rd−2G−2W2 E2=0.5*(D−2Rd−2G−E1) where E1 is a diameter of the electrode connection (50, 50'), E2 is a width of an exposed area parallel to a surface of the electrode connection (50, 50') in the outer surface (52a) of the second end surface (52) of the battery box (51), D is an outer diameter of the battery box (51), R da width of a circular area at an edge of the battery box (51), measured on a plane, G is an exposure width of the outer seal (54a) by an edge of the electrode terminal (50, 50'), W1 is a maximum value among distances between any two points selected in an edge of the first overlap area, and W2 is a maximum value among distances between two points where a plurality of linear lines passing through the center of the electrode terminal (50, 50') meet an edge of the second overlap area. [43] Cylindrical battery cell (70) according to any one of claims 1 to 42, wherein a ratio obtained by dividing a diameter of the cylindrical battery cell (70) by its height is greater than 0.

4. [44] Cylindrical battery cell (70) according to any one of claims 1 to 43, wherein the electrode connection (50, 50') provides a circular contact surface which is exposed to the outside of the battery box (51). [45] Battery pack (200) comprising several cylindrical battery cells according to any one of claims 1 to 44. [46] Battery pack (200) according to claim 45, wherein the multiple cylindrical battery cells (70; 201) are arranged in one or more rows and columns, and wherein cylindrical battery cells (70) are arranged such that the respective electrode terminals (50, 50') and second end faces (52) of the battery boxes (51) are at the top. [47] Battery pack (200) according to claim 46, further comprising: several busbars (150) configured to connect the multiple cylindrical battery cells (70; 201) in series and / or parallel, wherein the multiple busbars (150) are arranged over the multiple cylindrical battery cells (70; 201), where each busbar (150) has: - a body section designed to extend between electrode terminals (50, 50') of adjacent cylindrical battery cells (70); - several first busbar connections (152), each designed to extend in one lateral direction from the body section (50a) and electrically coupled to the electrode connection (50, 50') of the cylindrical battery cell (70) located in one lateral direction; and - several second busbar connections (153), each designed to extend in the opposite lateral direction from the body section (50a) and electrically coupled to the outer surface (52a) of the second end surface (52) of the battery box (51) of the cylindrical battery cell (70), which is located in the opposite lateral direction. [48] ​​Vehicle comprising at least one battery pack (200) according to any one of claims 45 to 47.

Images