Riveting structure of electrode terminal, and secondary battery, battery pack and automobile comprising same

Abstract

The present specification provides a caulking structure of an electrode terminal, and a secondary battery, a battery pack, and an automobile including the same, the caulking structure of an electrode terminal comprising: a battery case having an open side; an electrode terminal crimped through a through-hole formed in the bottom surface of the battery case; and a gasket sandwiched between the battery case and the electrode terminal, in which the electrode terminal includes: a main body portion inserted into the through-hole; an outer flange part extending from one side edge of the main body part exposed through the outer surface of the bottom surface of the battery case along the outer surface; and an inner flange part extending from the other side edge of the main body part exposed through the inner surface of the bottom surface of the battery case toward the inner surface, in which the main body part and the outer flange part have inner cavities connected to each other, and the inner flange part extends from the other side edge of the main body part exposed through the inner surface of the bottom surface of the battery case. The inner flange portion has an opening portion that is connected to the inner cavity and opens toward the inside direction of the battery case.

Description

[0001] This application is a divisional application of the original invention patent application No. 202210149926.1 (filed on February 18, 2022, invention title: Riveting structure of electrode terminals and secondary battery, battery pack and automobile including the same). Technical Field

[0002] This invention relates to a riveting structure for electrode terminals and to a secondary battery, battery pack, and automobile including the same.

[0003] This application claims the benefit of Korean Patent Application No. 10-2021-0022867, filed with the Korean Patent Office on February 19, 2021, the entire contents of which are contained in this specification. Background Technology

[0004] Secondary batteries, which are highly adaptable and have high energy density and other electrical properties, are widely used not only in portable devices, but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources.

[0005] Such rechargeable batteries not only have the primary advantage of significantly reducing the use of fossil fuels, but also the advantage of producing no byproducts when using energy. Therefore, they are attracting much attention as a new energy source that is both environmentally friendly and improves energy efficiency.

[0006] Currently, widely used rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple batteries are sometimes connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, multiple batteries are sometimes connected in parallel to form a battery pack. Therefore, depending on the required output voltage and / or charge / discharge capacity, the number of batteries included in a battery pack and the electrical connection method can be designed in various ways.

[0007] On the other hand, as types of unit secondary battery cells, cylindrical, square, and pouch batteries are disclosed. A cylindrical battery has a separator membrane sandwiched between the anode and cathode as an insulator, which is then rolled up to form a gel roll-shaped electrode assembly, which, along with the electrolyte, is inserted into the battery casing to form the battery.

[0008] At this point, there is also a structure for the anode electrode terminal of the cylindrical secondary battery, which adopts a rivet-type anode electrode terminal structure that penetrates the bottom surface of the battery casing, in order to replace the cover of the existing sealed body that seals the opening of the battery casing. However, the welding process used to achieve the connection between the anode electrode terminal and the anode current collector needs to be carried out through the core of the gel roll, so there are some difficulties when welding in a narrow space.

[0009] [Preliminary Technology Documents]

[0010] [Patent Documents]

[0011] Korean Patent Publication No. 10-2020-0141200 (published on December 18, 2020) Summary of the Invention

[0012] Technical problems to be solved

[0013] The present invention aims to solve the following problem: when laser welding is performed on the upper part of the opening of the battery casing through the core inside the casing, the risk of defects such as beam interference, weld slag flowing into the battery, and weak welds increases.

[0014] means of solving technical problems

[0015] This specification provides a riveting structure for electrode terminals, comprising: a battery housing with an open side; an electrode terminal riveted through a through hole formed on the bottom surface of the battery housing; and a gasket sandwiched between the battery housing and the electrode terminal, wherein the electrode terminal comprises: a body portion inserted into the through hole; an outer flange portion extending along the outer surface of the body portion exposed through the outer surface of the bottom surface of the battery housing; and an inner flange portion extending toward the inner surface of the body portion exposed through the inner surface of the bottom surface of the battery housing, wherein the body portion and the outer flange portion have internal cavities connected to each other, and the inner flange portion has an opening connected to the internal cavity and opening toward the inside of the battery housing.

[0016] In one embodiment of this specification, the inner diameter of at least a portion of the inner cavity of the external flange may be larger than the inner diameter of the main body.

[0017] In one embodiment of this specification, the inner diameter of at least a portion of the inner cavity of the external flange may decrease as it moves from the outside of the battery case toward the inside.

[0018] In one embodiment of this specification, the side thickness of the main body portion of the electrode terminal may be 5% or more and 40% or less of the maximum distance between the inner surfaces of the main body portion.

[0019] In one embodiment of this specification, the maximum length of the outer surface of the external flange can be 10% or more and 40% or less, based on the maximum length of the bottom surface of the battery case.

[0020] This specification provides a secondary battery according to one embodiment, comprising: an electrode assembly having a sheet-shaped first electrode and a second electrode wound together with a separator membrane, and including uncoated portions of the first electrode and the second electrode extending from both ends; a battery case housing the electrode assembly and electrically connected to the second electrode; and electrode terminals riveted through through holes formed in the bottom surface of the battery case and electrically connected to the first electrode, the electrode terminals including: a main body portion inserted into the through hole; and an external flange portion exposed from one side of the main body portion through the outer surface of the bottom surface of the battery case. The outer edge extends along the outer surface; and the inner flange extends from the other side edge of the main body portion exposed through the inner surface of the bottom surface of the battery case toward the inner surface, wherein the main body portion and the outer flange portion have an internal cavity connected to each other, and the inner flange portion has an opening connected to the internal cavity and opening toward the inside of the battery case; a first current collector electrically connected to the uncoated portion of the first electrode; a gasket sandwiched between the electrode terminal and the through hole; and a sealing body sealing the open end of the battery case to achieve insulation from the battery case.

[0021] In one embodiment of this specification, the uncoated portion of the first electrode can be welded to the first current collector for electrical connection.

[0022] In one embodiment of this specification, the first current collector further includes a fastening part, which clamps the first current collector through the opening of the inner flange of the electrode terminal into the body portion of the electrode terminal and the inner cavity of the outer flange portion. The fastening part of the first current collector can be electrically connected to at least a portion of the inner surface of the body portion of the electrode terminal.

[0023] In one embodiment of this specification, the first current collector can be electrically connected to the inner surface of the inner flange of the electrode terminal.

[0024] In one embodiment of this specification, the fastening portion of the first current collector can be electrically connected to at least a portion of the inner surface of the outer flange of the electrode terminal.

[0025] In one embodiment of this specification, at least a portion of the inner diameter of the inner cavity of the outer flange of the electrode terminal may be larger than the inner diameter of the main body of the first current collector, and a protrusion is formed at the end of the fastening portion of the first current collector so as to be riveted to the interior of the outer flange.

[0026] In one embodiment of this specification, the outer diameter of the fastening part may be larger than the inner diameter of the main body part.

[0027] In one embodiment of this specification, the ratio of the outer diameter of the fastening portion of the first current collector to the inner diameter of the main body portion of the electrode terminal may be from 1:1 to 1.01:1.

[0028] In one embodiment of this specification, the ratio of the maximum outer diameter of the protruding portion of the fastening part of the first current collector to the inner diameter of the main body of the electrode terminal may be from 1.005:1 to 1.1:1.

[0029] This specification provides a battery pack comprising a plurality of the aforementioned secondary batteries according to one embodiment.

[0030] This specification provides an embodiment of a vehicle that includes at least one of the battery packs described above.

[0031] Invention Effects

[0032] According to one aspect of the present invention, the electrode terminal structure of the secondary battery is improved, overcoming the difficulties in welding in a narrow space and the resulting increase in adverse risks caused by welding residue. The electrode terminals can be fastened to the current collector through a simpler process. Attached Figure Description

[0033] Figure 1 This is a plan view showing the structure of the electrode plates used in a secondary battery.

[0034] Figure 2 This is a diagram illustrating the winding process of the electrode assembly included in a secondary battery.

[0035] Figure 3 It is shown Figure 2 A diagram showing the process of welding a current collector plate to the bent surface of the uncoated part in an electrode assembly.

[0036] Figure 4 This diagram illustrates the slag formation that occurs when welding electrode terminals and current collectors with existing rivet-type welding.

[0037] Figure 5 This is a diagram that briefly illustrates the process of clamping the electrode terminals and the first current collector according to one embodiment of this specification.

[0038] Figure 6 This is a diagram that briefly illustrates the riveting structure of the electrode terminals according to one embodiment of this specification.

[0039] Figure 7 This is a cross-sectional view showing the fastening part of the first collector plate having protrusions.

[0040] Figure 8 This is a schematic diagram of the shape of the first collector board in this manual.

[0041] Figure 9 This is a cross-sectional view of a secondary battery cut along the length direction Y according to an embodiment of this specification.

[0042] Figure 10 This is a schematic plan view illustrating an electrode plate structure according to one embodiment of this specification.

[0043] Figure 11 This is a cross-sectional view of an electrode assembly in which the uncoated portion of the electrode plate is cut along the length direction Y according to one embodiment of this specification and applied to the first electrode and the second electrode.

[0044] Figure 12 This is a cross-sectional view of an electrode assembly with the uncoated portion bent along the length direction Y, according to an embodiment of this specification.

[0045] Figure 13 This is a diagram illustrating a simplified configuration of a battery pack comprising a plurality of cylindrical battery cells according to one embodiment of this specification.

[0046] Figure 14 This is a diagram illustrating a simplified configuration of a car including a battery pack according to one embodiment of this specification.

[0047] Marker description

[0048] 71, 100: Electrode assemblies

[0049] 10: Anode plate

[0050] 11: Cathode plate

[0051] 10a, 73: Uncoated portion of the first electrode

[0052] 11a, 72: Uncoated portion of the second electrode

[0053] 12: Separation membrane

[0054] 20, 91: Collector

[0055] 21, 92: Active substances

[0056] 22, 93: Uncoated sections

[0057] 30: First collector board

[0058] 30a: Fastening part

[0059] L1: Outer diameter of the fastening part of the first collector plate

[0060] L2: The maximum outer diameter of the protruding portion in the fastening part of the first collector plate.

[0061] 31, 78: Second collector board

[0062] 50: Electrode terminal

[0063] 50a: Main body

[0064] R1: Inner diameter of the main body

[0065] 50b: External flange portion

[0066] 50c: Internal flange portion

[0067] 51: Battery casing

[0068] 53: Through hole

[0069] 54: Gasket

[0070] 55: Insulator

[0071] 56: protrusion

[0072] 70: Secondary battery

[0073] 74: Sealing body

[0074] 74a: Cover plate

[0075] 74b: Sealing gasket

[0076] 75: Wrinkled area

[0077] 76: Curled edge

[0078] 76a: Inner circumferential surface of the rolled edge

[0079] 77: Ventilation gap

[0080] 78a: At least a portion of the edge that does not contact the uncoated portion of the second electrode

[0081] 80: Cavity located in the core of the electrode assembly

[0082] 90: Electrode

[0083] 93a: Slicing

[0084] 93': Uncoated section on the core side

[0085] 94: Insulating coating

[0086] 200: Battery pack

[0087] 201: Cylindrical secondary battery unit

[0088] 202: Battery pack casing

[0089] V: Car

[0090] P: Internal cavity

[0091] Q: Opening

[0092] A: Overcompensation Detailed Implementation

[0093] The following is a more detailed description of this instruction manual.

[0094] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Before proceeding, the terms and words used in this specification and claims should not be limited to their ordinary or dictionary meanings. Given the principle that inventors may appropriately define terms and concepts in order to best illustrate their invention, they should be interpreted as meanings and concepts consistent with the technical concept of the present invention.

[0095] Therefore, the embodiments described in this specification and the configurations shown in the accompanying drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. It should be understood that at the time of filing this application, there may be various equivalents and multiple modifications that can replace these.

[0096] Furthermore, to aid in understanding the invention, the dimensions of some constituent elements in the drawings are sometimes exaggerated and not shown in actual scale. Also, in different embodiments, the same reference numerals may be used to label the same constituent elements.

[0097] The statement that two comparison objects are identical means "substantially identical." Therefore, substantially identical can include cases with deviations considered low within the art, such as deviations within 5%. Furthermore, uniformity of a parameter within a predetermined region can indicate uniformity from an average perspective.

[0098] In this specification, "above" not only refers to a physical connection on a layer, but also to being located above from a positional point of view. That is, other layers may exist between layers located above a certain layer.

[0099] In this specification, when a part is described as "including" a certain constituent element, it means, unless otherwise specified, that other constituent elements may also be included, not that other constituent elements are excluded.

[0100] This specification provides a riveting structure for electrode terminals, including: a battery housing with an open side; an electrode terminal riveted through a through hole formed on the bottom surface of the battery housing; and a gasket sandwiched between the battery housing and the electrode terminal, wherein the electrode terminal includes: a main body portion inserted into the through hole; an outer flange portion extending along the outer surface of the main body portion exposed through the outer surface of the bottom surface of the battery housing; and an inner flange portion extending toward the inner surface of the main body portion exposed through the inner surface of the bottom surface of the battery housing, wherein the main body portion and the outer flange portion have internal cavities connected to each other, and the inner flange portion has an opening connected to the internal cavity and opening toward the inside of the battery housing.

[0101] When using existing rivet-type electrode terminals that penetrate the bottom of the battery casing as electrode terminals for secondary batteries, the welding process to bond the electrode terminals to the current collector requires the use of a gel roll core, which presents some difficulties when welding in a narrow space. Furthermore, when laser welding is performed on the upper part of the battery casing opening using a core inside the casing, the risk of defects such as beam interference, weld slag flowing into the battery, and weak welds increases.

[0102] Figure 4 This diagram illustrates the laser welding process of a current collector and conventional rivet-type terminals, showing an example where weld slag produced during welding can remain inside the secondary battery as metallic impurities. Such metallic impurities inside the secondary battery can potentially cause micro-short circuits.

[0103] The electrode terminal 50 of the present invention has a riveting structure, which is exposed through a through hole 53 formed on the bottom surface of the battery case 51 and then riveted. At this time, the electrode terminal of the present invention has a structure in which a cavity P is formed inside, so that the current collector 30 is clamped in the cavity P of the electrode terminal.

[0104] That is, the electrode terminal of the present invention has a structure in which the electrode terminal and the current collector are clamped in the internal cavity and abut against each other to achieve electrical connection, rather than achieving electrical connection by welding to the current collector. Figure 5 This is a diagram illustrating the formation process of the electrode terminal with a riveting structure according to the present invention. Referring to the bottommost drawing, the electrode terminal and current collector of the present invention are clamped in the cavity formed inside the electrode terminal, which is indicated by the red dashed line.

[0105] Therefore, the secondary battery with the riveted structure of the electrode terminals of the present invention does not use a welding process when combining the electrode terminals and the current collector, thus having the advantage of overcoming the adverse dangers caused by beam interference and the appearance of welding slag.

[0106] The electrode terminals of the present invention have a riveting structure and are riveted through a through hole formed on the bottom surface of the battery case, wherein the gasket is disposed between the battery case and the electrode terminals.

[0107] Figure 5 The process of riveting the electrode terminals located between the through holes of the battery casing according to the present invention is illustrated. The top of the electrode terminals is bent so that the outer diameter of the portion of the electrode terminal protruding to the outside of the battery casing is larger than the outer diameter of the through hole in the battery casing, thereby forming a riveting structure for the electrode terminals. During this process, through the aforementioned pressure pressing, the portion of the gasket protruding to the outside of the battery casing is also bent at the same angle as the electrode terminals. The outer diameter of the through hole refers to the diameter of the through hole.

[0108] The electrode terminal of the present invention, processed as described above, includes: a main body portion 50a inserted into the through hole 53; an outer flange portion 50b extending along the outer surface 52a of the main body portion 50a, which is exposed through the outer surface 52a of the bottom surface 52 of the battery case 51; and an inner flange portion 50c extending toward the inner surface 52b of the main body portion 50a, which is exposed through the inner surface 52b of the bottom surface 52 of the battery case 51. The main body portion 50a and the outer flange portion 50b have an internal cavity P connected to each other, and the inner flange portion 50c has an opening Q connected to the internal cavity P and opening toward the inside of the battery case 51. Here, the terms "main body portion," "outer flange portion," and "inner flange portion" are used to define the regions constituting the electrode terminal.

[0109] Figure 6 This is a cross-sectional view showing the riveting structure of the electrode terminals of the present invention cut along its length. The area indicated by dashed lines in the portion exposed to the outside of the battery casing of the electrode terminals is the outer flange portion 50b. The area provided between the through holes in the battery casing and also indicated by dashed lines is the main body portion 50a. The portion of the electrode terminals extending into the inner surface of the bottom surface of the battery casing, indicated by dashed lines, is the inner flange portion 50c. The aforementioned main body portion and the aforementioned outer flange portion are included in the attached... Figure 6 The internal cavities, denoted by P, are interconnected. The aforementioned internal flanges have... Figure 6 The opening, denoted by Q, is connected to the internal cavity P.

[0110] In one embodiment of this specification, the inner diameter of at least a portion of the inner cavity of the outer flange may be larger than the inner diameter of the inner cavity of the main body. By forming the inner diameter of at least a portion of the inner cavity of the outer flange to be larger than the inner diameter of the inner cavity of the main body, one end of the current collector (described later) abuts against the inner surface of the outer flange, thereby fixing the current collector and preventing it from moving up and down.

[0111] In one embodiment of this specification, the inner diameter of at least a portion of the inner cavity of the external flange can decrease from the outside to the inside of the battery casing. Through the range where the inner diameter of at least a portion of the inner cavity of the external flange decreases, one end of the current collector, described later, can be more securely fixed to the inner surface of the external flange.

[0112] In one embodiment of this specification, the inner surface of the main body of the electrode terminal can be connected to the inner surface of the inner flange in a straight manner.

[0113] In one embodiment of this specification, the thickness of the main body portion of the electrode terminal may be constant.

[0114] In one embodiment of this specification, the maximum length between the inner surfaces of the main body portion of the electrode terminal may be the same as or less than the maximum length between the inner surfaces of the outer flange portion of the electrode terminal.

[0115] In one embodiment of this specification, the outer flange of the electrode terminal may include regions having different thicknesses from each other.

[0116] In one embodiment of this specification, the thickness t1 of at least a portion of the outer flange of the electrode terminal may be greater than the side thickness t2 of the main body. The side thickness of the main body represents the distance between the outer surface and the inner surface of the main body of the electrode terminal. Figure 6 The symbol t2 is used to represent this.

[0117] In one embodiment of this specification, the side thickness of the main body portion of the electrode terminal may be 5% to 40% or less of the inner diameter R1 of the main body portion of the electrode terminal, may be 7% to 40% or less, may be 10% to 35% or less, or may be 10% to 25% or less. The inner diameter of the main body portion represents the distance between the internal surfaces of the main body portion. Figure 6 R1 is used to represent it.

[0118] When the above-mentioned range is met, the durability of the main body can be improved, so that even if the current collector plate described later barely clamps the internal cavity of the main body, the main body of the electrode terminal can be prevented from being damaged, and the riveting process of the electrode terminal can be easily realized.

[0119] In one embodiment of this specification, the inner diameter of the main body, the maximum inner diameter of the internal cavity of the external flange, and the inner diameter of the opening of the internal flange can be designed based on the thickness of the main body of the electrode terminal, the diameter of the through hole of the battery case, and the thickness of the gasket. Specifically, the design can be based on the ability of the riveted electrode terminal to block the gap inside the battery case, the interference fit of the current collector (described later), and the ease of insertion of the fastening part of the current collector.

[0120] In one embodiment of this specification, the inner diameter of the main body portion may be 4 mm or more and 11 mm or less, or 4 mm or more and 8 mm or less, or 5 mm or more and 8 mm or less.

[0121] In one embodiment of this specification, the maximum inner diameter of the internal cavity of the external flange can be 5 mm or more and 15 mm or less, or 7 mm or more and 12 mm or less, or 9 mm or more and 12 mm or less.

[0122] In one embodiment of this specification, the inner diameter of the opening of the inner flange portion may be 4 mm or more and 11 mm or less, or 5 mm or more and 10 mm or less, or 7 mm or more and 10 mm or less.

[0123] In one embodiment of this specification, the maximum length of the outer surface of the external flange can be more than 10% to less than 40% based on the maximum length of the bottom surface of the battery case, or more than 15% to less than 35%, or more than 20% to less than 30%.

[0124] If the above conditions are met, space can be properly ensured at the electrode terminals for solderable busbars and other electronic wiring components.

[0125] In one embodiment of this specification, the electrode terminal 50 is made of a conductive metal. In one example, the electrode terminal 50 may be made of aluminum, but the present invention is not limited thereto.

[0126] In one embodiment of this specification, the battery casing 51 is made of a conductive metal material. In one example, the battery casing 51 may be made of steel, but the present invention is not limited thereto.

[0127] In one embodiment of this specification, the gasket 54 may be made of a polymer resin that has insulating and elastic properties. In one example, the gasket 54 may be made of polypropylene, polybutylene terephthalate, polyfluoroethylene, etc., but the present invention is not limited thereto.

[0128] In one embodiment of this specification, the upper and lower ends of the inner wall of the through hole 53, which is perpendicular to the bottom surface of the battery case 51, are corner-cut to form a tapered surface toward the electrode terminal 50. However, the upper and / or lower ends of the inner wall of the through hole 53 can be deformed into a gentle curved surface with curvature. In this case, the pressure applied to the gasket 54 near the upper and / or lower ends of the inner wall of the through hole 53 can be further reduced.

[0129] According to one embodiment of this specification, the riveting structure of the electrode terminal 50 can be formed using a calking jig that moves up and down, a spinning process, or a rotary riveting. First, a preform (not shown) of the electrode terminal 50 with a gasket attached is inserted into a through hole 53 formed in the bottom surface 52 of the battery casing 51. The preform refers to the electrode terminal before riveting.

[0130] As an example, on the outside of the battery casing, an external calking jig is used to process the pre-formed electrode terminal into a riveted electrode terminal, and an internal calking jig is inserted into the inner space of the battery casing, thereby preventing the inner deformation caused by the external calking jig.

[0131] After the preform is pressurized using a calking jig, the calking jig is separated from the battery casing 51, and then... Figure 6 As shown, the riveting structure of the electrode terminal 50 of the present invention can be obtained.

[0132] Preferably, the gasket 54 is fully compressed to ensure excellent encapsulation strength without physical damage during the riveting of the preform.

[0133] In one embodiment of this specification, preferably, when the gasket 54 is made of polybutylene terephthalate, the compression ratio of the gasket 54 is 50% or more at the point when the gasket 54 is compressed to its minimum thickness. The compression ratio is the proportion of the thickness change before and after compression relative to the initial thickness.

[0134] In one embodiment of this specification, preferably, when the gasket 54 is made of polyvinyl fluoride, the compression rate of the gasket 54 is 60% or more at the point when the gasket 54 is compressed to its minimum thickness.

[0135] In one embodiment of this specification, preferably, when the gasket 54 is made of polypropylene, the compression rate of the gasket 54 is 60% or more at the point when the gasket 54 is compressed to its minimum thickness.

[0136] The above-described riveting structure for the electrode terminals of the present invention can be applied to a secondary battery, which includes: an electrode assembly comprising a sheet-shaped first electrode and a second electrode wound together with a separation membrane and including uncoated portions of the first electrode and the second electrode extending from both ends; a first current collector welded to the uncoated portion of the first electrode; a gasket disposed between the electrode terminals and the through hole; and a sealing body that seals the open ends of the battery casing to achieve insulation from the battery casing.

[0137] In one embodiment of this specification, the electrode terminals can be combined with and electrically connected to the first current collector. Specifically, the electrode terminals are electrically connected to the first current collector by direct bonding, rather than by soldering.

[0138] The first current collector also includes a fastening part, which inserts into and clamps the main body of the electrode terminal and the inner cavity of the outer flange through the opening of the inner flange of the electrode terminal. The fastening part can be electrically connected to at least a portion of the inner surface of the main body. More specifically, the fastening part can directly contact at least a portion of the inner surface of the main body to achieve electrical connection. Figure 8 This is a schematic diagram of the first current collector of the present invention, which has a structure in which a cylindrical fastener is attached to the center of the disc-shaped current collector.

[0139] The first current collector of the present invention, by including the fastening part, has the advantage of being able to be combined with the electrode terminal without the need for a welding process. Compared with the existing riveted electrode terminal structure, the electrode terminal and the first current collector have a wider contact surface, so they can be smoothly electrically connected to the electrode terminal, while reducing the high resistance of the first current collector.

[0140] In one embodiment of this specification, the fastening portion of the first current collector may include an internal cavity.

[0141] In one embodiment of this specification, the height of the fastening portion of the first current collector can be 2mm or more to 8mm or less, or 3mm or more to 7mm or less, or 4mm or more to 6mm or less.

[0142] In one embodiment of this specification, the first current collector can be electrically connected to the inner surface of the inner flange of the electrode terminal. More specifically, the first current collector can directly contact and be electrically connected to the inner surface of the inner flange of the electrode terminal.

[0143] In the first current collector of this specification, the side opposite to the side that is bonded to the uncoated part of the first electrode can be electrically connected to the inner surface of the inner flange of the electrode terminal. More specifically, it can directly contact and be electrically connected to the inner surface of the inner flange of the electrode terminal.

[0144] In one embodiment of this specification, the fastening portion may be electrically connected to at least a portion of the inner surface of the outer flange. More specifically, the fastening portion may directly contact and be electrically connected to at least a portion of the inner surface of the outer flange.

[0145] Reference Figure 5 as well as Figure 6 This shows the situation where the fastening part of the first current collector and the electrode terminal are in direct contact.

[0146] The connection structure between the first current collector and the electrode terminals in this specification is equivalent to an interference fit connection structure between the electrode terminals and the first current collector. That is, the present invention is configured to utilize a physical contact connection between the first current collector with a fastening portion and the electrode terminals, thereby eliminating the hazards associated with the welding process. Figure 5 In the figure, A represents the interference fit between the outer surface of the fastening part of the first collector plate and the inner surface of the main body of the electrode terminal.

[0147] In one embodiment of this specification, the outer diameter L1 of the fastening portion of the first current collector can be larger than the inner diameter R1 of the main body portion of the electrode terminal.

[0148] In one embodiment of this specification, the ratio of the outer diameter L1 of the fastening portion of the first current collector to the inner diameter R1 of the main body portion of the electrode terminal can be 1:1 to 1.01:1, 1:1 to 1.008:1, or 1:1 to 1.005:1. When the above ranges are satisfied, the fixing force of the fastening portion of the current collector can be strengthened.

[0149] Reference Figure 5 The outer diameter of the fastening part of the first current collector plate refers to the diameter of the outer surface of the fastening part opposite to the inner surface of the main body of the electrode terminal. Figure 5 L1 is used to represent it.

[0150] In one embodiment of this specification, the inner diameter of at least a portion of the inner cavity of the outer flange may be larger than the inner diameter of the main body, and at least one end of the fastening portion may be formed with a protrusion for riveting to the interior of the outer flange. For example, the protrusion may be located on the side of the fastening portion in the inner cavity of the outer flange.

[0151] Reference Figure 7Within the internal cavity of the aforementioned electrode terminal, the protrusion of the fastening portion of the first current collector is riveted using an interference fit. Both the first current collector and the aforementioned electrode terminal are made of conductive metal; therefore, by clamping the protrusion of the first current collector into the internal cavity of the electrode terminal with a relatively strong force, slight deformations occur in each component element, simultaneously achieving riveting.

[0152] The maximum outer diameter L2 of the protruding portion of the fastening part of the first current collector can be larger than the inner diameter R1 of the main body of the electrode terminal.

[0153] In one embodiment of this specification, the ratio of the maximum outer diameter L2 of the protruding portion of the fastening part of the first current collector to the inner diameter R1 of the main body of the electrode terminal can be 1.005:1 to 1.1:1, 1.005:1 to 1.05:1, 1.005:1 to 1.03:1, 1.005:1 to 1.02:1, or 1.005:1 to 1.015:1.

[0154] When the above range is met, it is preferable to strengthen the fixing force. The protrusion is blocked at the boundary between the main body of the electrode terminal and the outer flange when the interference fit is completed, thereby preventing the first current collector from being inserted and detached in the opposite direction.

[0155] Reference Figure 7 The maximum outer diameter L2 of the protruding portion in the aforementioned fastening part represents the outer diameter of the fastening part when the portion with the most protruding protrusions extending from the outer surface of the aforementioned fastening part is taken as the reference. Figure 7 It is represented by L2.

[0156] Therefore, when using the riveting structure of the electrode terminals according to the present invention, there is an advantage that no additional welding process is required for the electrical connection between the current collector and the electrode terminals.

[0157] The first current collector of the present invention is combined with and electrically connected to the electrode assembly.

[0158] In one embodiment of this specification, in the electrode assembly 100, the sheet-shaped first electrode and the second electrode are wound together with a separation membrane sandwiched between them, and include uncoated portions of the first electrode and the second electrode extending from their respective side ends.

[0159] The electrode assembly according to one embodiment of this specification may, for example, have a jelly-roll structure. The electrode assembly can be manufactured by rolling up a laminate formed by stacking a first electrode and a second electrode having a sheet shape at least once with a separation membrane sandwiched between them, with the center portion of the laminate as a reference.

[0160] That is, the anode plate and cathode plate have a structure in which an active material 21 is coated on a sheet-shaped current collector 20, and an uncoated portion 22 is included on one long side along the winding direction. In this case, an additional separation membrane can be provided on the outer peripheral surface of the electrode assembly 100 to achieve insulation from the battery case 51. Any gel roll structure known in the art can be applied to this invention without any limitation.

[0161] Figure 1 The structure of a current collector according to one embodiment of this specification is shown. Figure 2 The winding process of the current collector according to one embodiment of this specification is shown. Figure 3 The process of welding a current collector on the bent surface of the uncoated portion according to an embodiment of this specification is shown.

[0162] Reference Figures 1 to 3 The anode plate 10 and the cathode plate 11 have a structure in which an active material 21 is coated on a sheet-shaped current collector 20, and an uncoated portion 22 is included on one long side along the winding direction X.

[0163] like Figure 2 As shown, an electrode assembly is manufactured by sequentially stacking the anode plate 10 and cathode plate 11 together with two separation membranes 12 and then winding them in one direction X. At this time, the uncoated portions of the anode plate 10 and cathode plate 11 are arranged in opposite directions. After the winding process, the uncoated portions 10a of the anode plate 10 and 11a of the cathode plate 11 are bent towards the core side. Then, the current collector plate 30 and the second current collector plate 31 are welded to the uncoated portions 10a and 11a, respectively.

[0164] The uncoated anode portion 10a and the uncoated cathode portion 11a are not connected to any other electrode plates. The current collector 30 and the second current collector 31 are connected to external electrode terminals, forming a current path with a large cross-sectional area along the winding axis direction of the electrode assembly A (refer to the arrow). Therefore, it has the advantage of reducing the resistance of the secondary battery. This is because the resistance is inversely proportional to the cross-sectional area of ​​the current flow path.

[0165] In one embodiment of this specification, the first electrode includes an electrode active material layer disposed on a first current collector and on one or both sides of the first current collector. In the first current collector disposed at one end of the winding shaft of the electrode assembly, there is an uncoated portion of the first electrode without an electrode active material layer at its long side end along the winding direction. The uncoated portion of the first electrode is disposed at the upper part of the electrode assembly housed within the battery case in the height direction (the direction parallel to the Z-axis). That is, the first current collector includes an uncoated portion of the first electrode at its long side end that is not coated with electrode active material and exposes to the outside of the separation membrane.

[0166] In one embodiment of this specification, the second electrode includes a second electrode active material layer disposed on a second electrode current collector and on one or both surfaces of the second electrode current collector. An uncoated portion of the second electrode, excluding the second electrode active material layer, exists at the other end of the second electrode current collector in the width direction (the direction parallel to the Z-axis).

[0167] The uncoated portion of the second electrode is located at the lower part of the electrode assembly housed within the battery casing in the height direction (the direction parallel to the Z-axis). That is, the second electrode current collector may include a second uncoated portion at its long side end that is not coated with an electrode active material layer and is exposed to the outside of the separation membrane.

[0168] In one embodiment of this specification, the first electrode may be an anode plate and the second electrode may be a cathode plate.

[0169] In one embodiment of this specification, the first electrode may be a cathode plate and the second electrode may be an anode plate.

[0170] In one embodiment of this specification, the anodic active material coated on the anode plate and the cathode active material coated on the cathode plate can be active materials known in the art, without any limitation.

[0171] In one example, the anolyte may include a material with the general chemical formula A[A] x M y ]O 2+z The alkali metal compound represented by (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x ≥ 0, 1 ≤ x + y ≤ 2, 0.1 ≤ z ≤ 2; stoichiometric coefficients x, y, and z are selected in such a way that the compound maintains electrical neutrality).

[0172] In another example, the anolyte could be an alkaline metal compound xLiM disclosed in US Patent 6,677,082, US Patent 6,680,143, etc. 1 O2(1x)Li2M 2 O3 (M) 1 Includes at least one element having an average oxidation state of 3; M 2 Includes at least one element having an average oxidation state of 4; 0 ≤ x ≤ 1).

[0173] In yet another example, the anolyte can be of the general chemical formula LiAM. 1 x Fe 1x M2 yP 1y M 3 zO 4z (M 1 includes at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 includes at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 includes halogen elements selectively including F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients a, x, y, and z are selected in such a way that the compound maintains electrical neutrality) or lithium metal phosphate represented by Li3M2(PO4)3 [M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0174] Preferably, the anode active material may include primary particles and / or secondary particles aggregated from primary particles.

[0175] In one example, the cathode active material may be a carbon material, a lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO2 and SnO2 with a potential less than 2V can also be used as the cathode active material. As the carbon material, low-crystalline carbon and / or high-crystalline carbon, etc. can be used.

[0176] In one embodiment of this specification, the above separation membrane may use a porous polymer thin film. For example, a porous polymer thin film made of polyolefin-based polymers such as ethylene monomer polymer, propylene monomer polymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, etc. can be used alone, or they can be laminated and used. As another example, the separation membrane may use a common porous non-woven fabric, such as a non-woven fabric composed of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0177] At least one surface of the separation membrane may include a coating of inorganic particles. And it may also be that the separation membrane itself is composed of a coating of inorganic particles. The particles constituting the coating may have a structure combined with an adhesive so that there is an interstitial volume between adjacent particles.

[0178] The inorganic particles may be composed of an inorganic substance with a dielectric constant of 5 or more. As a non-limiting example, the above inorganic particles may include those selected from Pb(Zr, Ti)O3 (PZT), Pb 1x La xZr 1y Ti y O3 (PLZT), PB (Mg3Nb) 2 / 3 At least one substance in the group consisting of O3PbTiO3 (PMNPT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0179] Electrolytes can be those with A + B - Salts with similar structures. Among them, A... + Including Li + Na + K + Ions consisting of basic metal cations or combinations thereof. Additionally, B... - Including the choice 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- Any one or more anions that constitute a group.

[0180] Electrolytes can also be used in organic solvents. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0181] In one embodiment of this specification, the uncoated portion of the first electrode and / or the second electrode is bent from the outer periphery of the electrode assembly toward the core side, thereby forming bending surfaces at the upper and lower parts of the electrode assembly. Furthermore, a current collector can be welded to the bending surface formed by bending the uncoated portion of the first electrode, and a second current collector can be welded to the bending surface formed by bending the uncoated portion of the second electrode.

[0182] To alleviate the stress generated when the uncoated portion of the first electrode and / or the second electrode is bent, the first electrode and / or the second electrode may have different structures. Figure 12 This is a schematic plan view illustrating the structure of electrode 90 according to an embodiment of the present invention.

[0183] Reference Figure 10 The electrode 90 includes a sheet-shaped current collector 91, an active material layer 92 formed on at least one side of the current collector 91, and an uncoated portion 93 at the long side end of the current collector 91 where no active material is coated.

[0184] The aforementioned uncoated portion 93 may include multiple slices 93a formed by cutting. These multiple slices 93a form multiple groups, and the height (length in the Y direction) and / or width (length in the X direction) and / or spacing of the multiple slices 93a belonging to each group may be the same. The number of multiple slices 93a belonging to each group may be increased or decreased compared to the number shown in the accompanying drawings. The slices 93a may be trapezoidal in shape, and may also be modified into quadrilaterals, parallelograms, semicircles, or semi-ellipses. Preferably, the height of the slices 93a may increase in stages from the core side towards the outer periphery. Furthermore, the uncoated portion 93' adjacent to the core side may not include slices 93a, and the height of the uncoated portion 93' on the core side may be smaller than that of other uncoated portion areas.

[0185] In one embodiment of this specification, the electrode 90 may include an insulating coating 94 covering the boundary between the active material layer 92 and the uncoated portion 93. The insulating coating 94 comprises an insulating polymer resin and may optionally include inorganic fillers. The insulating coating 94 prevents the end of the active material layer 92 from contacting an opposing active material layer through the separation membrane, thus structurally supporting the bending of the segment 93a. Therefore, when the electrode 90 is wound into an electrode assembly, preferably, at least a portion of the insulating coating 94 is exposed to the outside from the separation membrane.

[0186] Figure 10 This is a cross-sectional view of an electrode assembly A, which is cut along the length direction Y according to an embodiment of this specification, in which the uncoated portion of electrode 90 is applied to the first electrode and the second electrode.

[0187] Reference Figure 13 The uncoated portion 72, protruding downwards, extends from the first electrode, and the uncoated portion 73, protruding upwards, extends from the second electrode. A simplified illustration of the height variation pattern of the uncoated portions 72 and 73 is provided. That is, the heights of the uncoated portions 72 and 73 can vary irregularly depending on the location of the cut section. For example, if the side portion of the trapezoidal slice 93a is cut, the height of the uncoated portion in the section is lower than the height of the slice 93a. Therefore, it should be interpreted that the heights of the uncoated portions 72 and 73 shown in the drawing illustrating the cross-section of electrode assembly A correspond to the average height of the uncoated portions contained in each coil.

[0188] like Figure 12 As shown, the uncoated portions 72 and 73 can be bent from the outer periphery of the electrode assembly A toward the core. Figure 11 In the diagram, the bent portion 101 is indicated by a dashed box. When the uncoated portions 72 and 73 are bent, multiple adjacent slices in the radial direction overlap each other to form multiple layers, creating a bending surface 102 on the upper and lower parts of the electrode assembly A. At this time, the uncoated portion on the core side ( Figure 10 Because of its low height, the 93' section will not bend. The height h of the innermost bent section is the same as or smaller than the radial length r of the winding area formed by the uncoated core section 93' without the section structure. Therefore, the cavity 80 in the core of the electrode assembly A will not be closed by the multiple bent sections. If the cavity 80 is not closed, the electrolyte injection process is not difficult, and the electrolyte injection efficiency is improved.

[0189] Reference Figure 9 According to an embodiment of the present invention, a secondary battery includes a cylindrical battery case 51 that houses an electrode assembly 71 and is electrically connected to an uncoated portion 72 of a first electrode. The battery case 51 has an open side (lower part). Furthermore, the bottom surface 52 of the battery case 51 has a structure in which the electrode terminals 50 are riveted to a through hole 53 via a caulking process.

[0190] In one embodiment of this specification, the secondary battery may include a gasket disposed between the electrode terminal and the through hole.

[0191] Reference Figure 9 According to one embodiment of this specification, the secondary battery 70 may further include a sealing body 74 that seals the open end of the battery casing 51 to achieve insulation from the battery casing 51. Preferably, the sealing body 74 may include a non-polar cover plate 74a and a sealing gasket 74b sandwiched between the edge of the cover plate 74a and the open end of the battery casing 51.

[0192] In this specification, the cover plate 74a may be made of conductive metals such as aluminum, steel, or nickel. Furthermore, the sealing gasket 74b may be made of insulating and elastic materials such as polypropylene, polybutylene terephthalate, or polyvinyl fluoride. However, the present invention is not limited to the raw materials of the cover plate 74a and the sealing gasket 74b.

[0193] In one embodiment of this specification, the cover plate 74a may include a vent 77 that ruptures when the pressure inside the battery case 51 exceeds a threshold. The vent 77 may be formed on both sides of the cover plate 74a. The vent 77 may be formed on the surface of the cover plate 74a with a continuous or discontinuous circular pattern, a straight line pattern, or other patterns.

[0194] In one embodiment of this specification, the battery housing 51 may include a wrinkled portion 75. In order to fix the sealing body 74, the wrinkled portion 75 extends into the inside of the battery housing 51 and bends to surround and fix the edge of the cover plate 74a together with the sealing gasket 74b.

[0195] In one embodiment of this specification, the battery housing 51 may include a rolled edge 76 pressed inward into the battery housing 51 in the region adjacent to the open end. When the sealing body 74 is fixed by the wrinkled portion 75, the rolled edge 76 supports the edge of the sealing body 74, especially the outer peripheral surface of the sealing gasket 74b.

[0196] In one embodiment of this specification, the secondary battery may further include a second current collector 31 welded to the uncoated portion 73 of the second electrode. The second current collector 31 is made of a conductive metal such as aluminum, steel, or nickel.

[0197] In one embodiment of this specification, at least a portion 78a of the edge of the second current collector 31 that does not contact the uncoated portion 72 of the second electrode is sandwiched between the rolled edge portion 76 and the sealing gasket 74b and is fixed by the wrinkled portion 75.

[0198] Optionally, at least a portion 78a of the edge of the second collector plate 31 can be fixed by welding to the inner peripheral surface 76a of the rolled edge portion 76 adjacent to the wrinkled portion 75.

[0199] In one embodiment of this specification, an insulator may be disposed between the first current collector and the inner surface of the battery casing. The insulator prevents contact between the first current collector and the battery casing. The insulator may also be sandwiched between the upper end of the outer peripheral surface of the electrode assembly and the inner surface of the battery casing. That is, the insulator may also be sandwiched between the uncoated portion of the first electrode and the inner surface of the sidewall portion of the battery casing. This is to prevent contact between the uncoated portion of the first electrode extending toward the closed portion of the battery casing and the inner peripheral surface of the battery casing.

[0200] In one embodiment of this specification, the uncoated portions 72 and 73 of the first electrode and / or the second electrode are bent from the outer periphery of the electrode assembly 71 toward the core side, thereby forming bending surfaces on the upper and lower parts of the electrode assembly 71. Furthermore, the first current collector 30 can be welded to the bending surface formed by bending the uncoated portion 72 of the first electrode, and the second current collector 31 can be welded to the bending surface formed by bending the uncoated portion 73 of the second electrode.

[0201] To alleviate the stress generated when the uncoated portions 72 and 73 are bent, the first electrode and / or the second electrode may have a similar design to... Figure 1 The electrode plates shown have different modified structures. Figure 10 This is a schematic plan view illustrating the structure of the electrode plate 90 according to a preferred embodiment of the present invention.

[0202] Reference Figure 8The electrode plate 90 includes a sheet-shaped current collector 91 made of a conductive foil material, an active material layer 92 formed on at least one side of the current collector 91, and an uncoated portion 93 at the long side end of the current collector 91 where no active material is coated.

[0203] Preferably, the uncoated portion 93 may include multiple slices 93a processed by cutting. The multiple slices 93a form multiple groups, and the height (length in the Y direction) and / or width (length in the X direction) and / or spacing of the multiple slices 93a belonging to each group may be the same. The number of multiple slices 93a belonging to each group may be increased or decreased compared to the number shown in the figures. The slices 93a may be trapezoidal in shape, and may also be modified into quadrilaterals, parallelograms, semicircles, or semi-ellipses. Preferably, the height of the slices 93a may increase in stages from the core side towards the outer periphery. Furthermore, the uncoated portion 93' on the core side adjacent to the core side may not include slices 93a, and the height of the uncoated portion 93' on the core side may be smaller than that of other uncoated portion areas.

[0204] In one embodiment of this specification, the electrode 90 may include an insulating coating 94 covering the boundary between the active material layer 92 and the uncoated portion 93. The insulating coating 94 comprises an insulating polymer resin and may optionally include inorganic fillers. The insulating coating 94 prevents the end of the active material layer 92 from contacting an opposing active material layer through the separation membrane, thus structurally supporting the bending of the segment 93a. Therefore, when the electrode 90 is wound into an electrode assembly, preferably, at least a portion of the insulating coating 94 is exposed to the outside from the separation membrane.

[0205] Figure 11 This is a cross-sectional view of an electrode assembly 100, which is cut along the length direction Y according to an embodiment of the present invention, in which the uncoated portion of the electrode plate 90 is applied to the first electrode and the second electrode.

[0206] Reference Figure 11 Electrode assembly 100 can be manufactured according to... Figure 2 The winding process described herein. For ease of explanation, the protruding structures of the uncoated portions 72 and 73 extending beyond the separation membrane are shown in detail, while the winding structures of the first electrode, the second electrode, and the separation membrane are omitted. The downward-protruding uncoated portion 72 extends from the first electrode, and the upward-protruding uncoated portion 73 extends from the second electrode. The pattern of height variation of the aforementioned uncoated portions 72 and 73 is briefly shown.

[0207] That is, the heights of the uncoated portions 72 and 73 can vary irregularly depending on the location of the cut section. For example, if the side portion of the trapezoidal slice 93a is cut, the height of the uncoated portion in the section is lower than the height of the slice 93a. Therefore, it should be interpreted that the heights of the uncoated portions 72 and 73 shown in the accompanying drawings illustrating the cross-section of the electrode assembly 100 correspond to the average height of the uncoated portions contained in each roll.

[0208] like Figure 12 As shown, the uncoated portions 72 and 73 can be bent from the outer periphery of the electrode assembly 100 toward the core side. Figure 11 In the diagram, the bent portion 101 is indicated by a dashed box. When the uncoated portions 72 and 73 are bent, multiple adjacent slices in the radial direction overlap each other to form multiple layers, creating a bending surface 102 on the upper and lower parts of the electrode assembly 100. At this time, the uncoated portion on the core side ( Figure 10 Because of its low height, the 93' segment does not bend. The height h of the segment bent on the innermost side is the same as or smaller than the radial length r of the winding area formed by the uncoated core portion 93' without the segment structure. Therefore, the cavity 80 in the core of the electrode assembly 100 is not closed by the multiple bent segments. If the cavity 80 is not closed, the electrolyte injection process is not difficult, and the electrolyte injection efficiency is improved.

[0209] According to an embodiment of the present invention, the cover plate 74a of the sealing body 74 of the secondary battery 70 is non-polarized. However, the second current collector 31 is connected to the side wall of the battery case 51, so that the outer surface 52a of the bottom surface 52 of the battery case 51 has a polarity opposite to that of the electrode terminals 50. Therefore, when multiple battery cells are connected in series and / or in parallel, wiring such as busbar connection can be performed on the upper part of the secondary battery 70 using the outer surface 52a of the bottom surface 52 of the battery case 51 and the electrode terminals 50. This increases the number of battery cells that can be installed in the same space and improves the energy density.

[0210] In one example, the anolyte may include a material with the general chemical formula A[A] x M y ]O 2+z The alkali metal compound represented by (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x ≥ 0, 1 ≤ x + y ≤ 2, 0.1 ≤ z ≤ 2; stoichiometric coefficients x, y, and z are selected in such a way that the compound maintains electrical neutrality).

[0211] In another example, the anode active material may be an alkaline metal compound xLiM disclosed in US6,677,082, US6,680,143, etc. 1 O2(1-x)Li2M 2 O3 (M 1 includes at least one or more elements having an average oxidation state of 3; M 2 includes at least one or more elements having an average oxidation state of 4; 0 ≤ x ≤ 1).

[0212] In yet another example, the anode active material may be a general chemical formula LiaM 1 x Fe 1x M 2 yP 1y M 3 zO 4z (M 1 includes at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 includes at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 includes 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 in such a way that the compound maintains electrical neutrality) or a lithium metal phosphate represented by Li3M2(PO4)3 [M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0213] Preferably, the anode active material may include primary particles and / or secondary particles aggregated from primary particles.

[0214] In one example, carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. may be used as the cathode active material. Metal oxides such as TiO2 and SnO2 with a potential less than 2V may also be used as the cathode active material. Low-crystalline carbon and / or high-crystalline carbon may be used as the carbon material.

[0215] The separation membrane can be a porous polymer film, such as a porous polymer film made of polyolefin polymers such as ethylene monomer polymers, propylene monomer polymers, ethylene / butene copolymers, ethylene / hexene copolymers, and ethylene / methacrylate copolymers, or they can be used in layers. As another example, the separation membrane can be a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fiber or polyethylene terephthalate fiber.

[0216] At least one surface of the separation membrane may include a coating of inorganic particles. Furthermore, the separation membrane itself may be composed of a coating of inorganic particles. The particles constituting the coating may have a structure bonded to a binder to create an interstitial volume between adjacent particles.

[0217] Inorganic particles can be composed of inorganic materials with a dielectric constant of 5 or higher. As a non-limiting example, the aforementioned inorganic particles may include those selected from Pb(Zr,Ti)O3 (PZT), Pb... 1x La x Zr 1y Ti y O3 (PLZT), PB (Mg3Nb) 2 / 3 At least one substance in the group consisting of O3PbTiO3 (PMNPT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0218] Electrolytes can be those with A + B - Salts with similar structures. Among them, A... + Including Li + Na + K + Ions consisting of basic metal cations or combinations thereof. Additionally, B... - Including the choice 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 - Any one or more anions that constitute a group.

[0219] Electrolytes can also be used in organic solvents. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0220] In this specification, the anodic active material coated on the anode plate and the cathode active material coated on the cathode plate may be any active material known in the art, without any limitation.

[0221] In one embodiment of this specification, the riveting structure of the electrode terminal 50 can be applied to a cylindrical secondary battery.

[0222] In one embodiment of this specification, the uncoated portion of the first electrode of the electrode assembly can be cut into the same shape as the current collector.

[0223] In one embodiment of this specification, the bent portion of the uncoated portion of the first electrode of the electrode assembly described above can be cut into the same shape as the current collector plate described above.

[0224] In one embodiment of this specification, the secondary battery can be a cylindrical secondary battery with a shape factor ratio (the ratio of the diameter of the cylindrical battery to its height, defined as the ratio of the diameter Φ to the height H) greater than 0.4. Here, the shape factor represents the diameter and height of the cylindrical secondary battery.

[0225] Currently, batteries with a form factor ratio of approximately 0.4 or less are being used. Specifically, this includes cells such as the 18650 and 21700. The 18650 cell has a diameter of approximately 18 mm and a height of approximately 65 mm, resulting in a form factor ratio of approximately 0.277. The 21700 cell has a diameter of approximately 21 mm and a height of approximately 70 mm, resulting in a form factor ratio of approximately 0.300.

[0226] According to one embodiment of this specification, the cylindrical secondary battery can be a 46110 battery cell, a 48750 battery cell, a 48110 battery cell, a 48800 battery cell, or a 46800 battery cell. In the numerical value representing the shape factor, the first two numbers represent the diameter of the battery cell, the next two numbers represent the height of the battery cell, and the remaining number 0 indicates that the cross-section of the battery cell is circular.

[0227] According to one embodiment of this specification, the secondary battery is a cylindrical battery cell, which may be a cylindrical secondary battery with a diameter of 46 mm, a height of 110 mm, and a shape factor ratio of 0.418.

[0228] According to one embodiment of this specification, the secondary battery is a cylindrical battery cell, which may be a cylindrical secondary battery with a diameter of 48 mm, a height of 75 mm, and a shape factor ratio of 0.640.

[0229] According to one embodiment of this specification, the secondary battery is a cylindrical battery cell, which may be a cylindrical secondary battery with a diameter of 48 mm, a height of 110 mm, and a shape factor ratio of 0.418.

[0230] According to one embodiment of this specification, the secondary battery is a cylindrical battery cell, which may be a cylindrical secondary battery with a diameter of 48 mm, a height of 80 mm, and a shape factor ratio of 0.600.

[0231] According to one embodiment of this specification, the secondary battery is a cylindrical battery cell, which may be a cylindrical secondary battery with a diameter of 46 mm, a height of 80 mm, and a shape factor ratio of 0.575.

[0232] The secondary battery according to one embodiment of this specification can be used to manufacture battery packs. Figure 13 This is a diagram that briefly illustrates the configuration of a battery pack according to an embodiment of the present invention.

[0233] Reference Figure 13 According to an embodiment of the present invention, the battery pack 200 includes an assembly of secondary battery cells 201 electrically connected to each other and a battery pack housing 202 housing the assembly. The cylindrical secondary battery cell 201 is the secondary battery cell according to the above embodiment. In the accompanying drawings, for ease of illustration, the busbars, cooling units, external terminals, and other components used for electrically connecting the plurality of cylindrical secondary battery cells 201 are omitted from the illustration.

[0234] The aforementioned battery pack 200 can be installed in a vehicle. For example, the vehicle can be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. Vehicles can be four-wheeled or two-wheeled. Figure 14 It is used to illustrate including Figure 13 A picture of a car with a 200 battery pack.

[0235] Reference Figure 14 A vehicle V according to one embodiment of this specification includes a battery pack 200 according to one embodiment of this specification. The vehicle V receives power from the battery pack 200 according to an embodiment of the present invention for operation.

[0236] While the present invention has been described above with limited embodiments and accompanying drawings, it is not limited thereto. Those skilled in the art to which this invention pertains should be able to make various modifications and variations within the technical concept and scope equivalent to the claims.

Claims

1. A riveting structure for electrode terminals, comprising: A battery casing, the battery casing including an open end on one side thereon; Electrode terminals are riveted through through holes formed in the bottom surface of the battery casing. as well as A gasket, which is sandwiched between the battery casing and the electrode terminals, The aforementioned electrode terminals include: The main body is inserted into the aforementioned through hole; An external flange portion extends along the outer surface of the bottom of the battery case from a first side of the main body portion exposed through the outer surface of the bottom of the battery case; and An internal flange extends from the second side of the main body portion, which is exposed through the inner surface of the bottom surface of the battery case, toward the inner surface of the bottom surface of the battery case. The main body and the external flange each have internal cavities that are connected to each other. The aforementioned internal flange portion has an opening that connects to the aforementioned internal cavity and opens toward the inside of the aforementioned battery casing.

2. The riveting structure for the electrode terminals according to claim 1, wherein, The battery casing includes a sidewall connected to the bottom surface, and the sidewall and the bottom surface are integrally formed.

3. The riveting structure for the electrode terminals according to claim 1, wherein, At least a portion of the inner diameter of the internal cavity of the aforementioned external flange is larger than the inner diameter of the aforementioned main body.

4. The riveting structure for the electrode terminals according to claim 1, wherein, The aforementioned external flange portion and the aforementioned main body portion are integrally formed.

5. The riveting structure for the electrode terminals according to claim 4, wherein, The inner diameter of the cavity portion of the external flange is larger than the inner diameter of the main body portion.

6. The riveting structure for the electrode terminals according to claim 1, wherein, The inner diameter of at least a portion of the internal cavity of the aforementioned external flange decreases in the direction from the outer side to the inner side of the aforementioned battery case.

7. The riveting structure for the electrode terminals according to claim 1, wherein, The internal cavity of the external flange includes a first part and a second part. The inner diameter of the first part is larger than the inner diameter of the internal cavity of the main body. The second part is disposed between the first part and the internal cavity of the main body, and the inner diameter of the second part decreases in the direction from the outside to the inside of the battery case.

8. The riveting structure for the electrode terminals according to claim 1, wherein, The side thickness of the main body of the aforementioned electrode terminal is 5% to 40% of the maximum internal width of the main body.

9. The riveting structure for the electrode terminals according to claim 1, wherein, The maximum width of the external exposed portion of the aforementioned electrode terminals is more than 10% and less than 40% of the maximum width of the bottom surface of the aforementioned battery case.

10. The riveting structure for the electrode terminals according to claim 1, wherein, The maximum width of the external exposed portion of the aforementioned electrode terminals is more than 15% and less than 35% of the maximum width of the bottom surface of the aforementioned battery case.

11. The riveting structure for the electrode terminals according to claim 1, wherein, The maximum width of the external exposed portion of the aforementioned electrode terminals is more than 20% and less than 30% of the maximum width of the bottom surface of the aforementioned battery case.

12. The riveting structure for the electrode terminals according to claim 1, wherein, The aforementioned electrode terminals are electrically connected to the current collector.

13. The riveting structure for the electrode terminals according to claim 1, wherein, The thickness of the bottom surface of the battery casing is greater than the thickness of the side wall of the battery casing.

14. A secondary battery, comprising: An electrode assembly, wherein a sheet-shaped first electrode and a second electrode are wound together with a separation membrane sandwiched between them, and includes an uncoated portion of the first electrode extending from two opposite ends of the first electrode and an uncoated portion of the second electrode extending from two opposite ends of the second electrode. The riveting structure of the electrode terminal according to any one of claims 1-12; The first current collector is electrically connected to the uncoated portion of the first electrode. A gasket, sandwiched between the electrode terminal and the through hole; and A sealing body is configured to seal the open end of the battery casing in order to insulate it from the battery casing.

15. The secondary battery according to claim 14, wherein, The uncoated portion of the first electrode is welded to and electrically connected to the first current collector.

16. The secondary battery according to claim 14, wherein, The first current collector also includes a fastening part, which is inserted and fitted into the inner cavity of the main body of the electrode terminal and the inner cavity of the outer flange of the electrode terminal through the opening of the inner flange of the electrode terminal. The fastening portion of the first current collector is electrically connected to at least a portion of the inner surface of the main body of the electrode terminal.

17. The secondary battery according to claim 14, wherein, The first current collector is electrically connected to the inner surface of the inner flange of the electrode terminal.

18. The secondary battery according to claim 16, wherein, The fastening portion of the first current collector is electrically connected to at least a portion of the inner surface of the outer flange of the electrode terminal.

19. The secondary battery according to claim 16, wherein, At least a portion of the inner diameter of the internal cavity of the outer flange of the aforementioned electrode terminal is larger than the inner diameter of the main body of the aforementioned electrode terminal, and At least one end of the fastening portion of the first current collector has a protrusion so as to contact the external flange portion.

20. The secondary battery according to claim 16, wherein, The outer diameter of the fastening part of the first current collector is larger than the inner diameter of the main body of the electrode terminal.

21. The secondary battery according to claim 16, wherein, The ratio of the outer diameter of the fastening part of the first current collector to the inner diameter of the main body of the electrode terminal is 1:1 to 1.01:

1.

22. The secondary battery according to claim 19, wherein, The ratio of the maximum outer diameter of the protruding portion of the fastening part of the first current collector to the inner diameter of the main body of the electrode terminal is 1.005:1 to 1.1:

1.

23. The secondary battery according to claim 14, wherein, The thickness of the bottom surface of the battery casing is greater than the thickness of the side wall of the battery casing.

24. A battery pack comprising a plurality of secondary batteries according to claim 14.

25. An automobile comprising at least one battery pack according to claim 24.

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