Battery, battery pack comprising it and automobile

Abstract

One embodiment of the present invention provides a cylindrical secondary battery, a battery pack including the same, and an automobile. The cylindrical secondary battery includes: an electrode assembly that defines a core and an outer peripheral surface by being wound around a winding shaft with a first electrode, a second electrode, and a separating membrane between them, wherein the first electrode and the second electrode respectively include a first uncoated portion and a second uncoated portion without an active material layer along the winding direction; a battery casing that houses the electrode assembly through an opening formed on one side; a cover having a venting portion that covers the opening and is electrically connected to the battery casing and the first uncoated portion, wherein the venting portion has a thickness thinner than the peripheral region; and a battery terminal that penetrates one surface of the battery casing and is electrically connected to the second uncoated portion.

Description

[0001] This application is a divisional application of the original invention patent application with application number 202210151589.X (application date: February 18, 2022, invention title: battery, battery pack therein and automobile). Technical Field

[0002] This invention relates to batteries, battery packs including the same, and automobiles. More specifically, this invention relates to a battery, battery packs including the same, and automobiles having a structure in which a cover covering one open portion of the battery casing can simultaneously function as a venting device and as a CID (current interruption device). Background Technology

[0003] Typically, when using batteries to make battery packs, multiple cylindrical batteries are usually arranged vertically inside a casing, and the upper and lower ends of the cylindrical batteries are used as anode terminals and cathode terminals, respectively, to electrically connect the multiple cylindrical batteries to each other.

[0004] This is because, in a cylindrical battery, the uncoated cathode portion of the electrode assembly housed inside the battery casing extends downwards and is electrically connected to the bottom surface of the battery casing, while the uncoated anode portion extends upwards and is electrically connected to the cover. In other words, in a cylindrical secondary battery, the bottom surface of the battery casing is typically used as the cathode terminal, and the cover covering the upper open portion of the battery casing is used as the anode terminal.

[0005] However, with the anode and cathode terminals of the cylindrical battery located on opposite sides, electrical connection components such as busbars for connecting multiple cylindrical batteries need to be applied to both the upper and lower parts of the cylindrical batteries. This results in a complex electrical connection structure for the battery pack.

[0006] Furthermore, in such a structure, components for insulation and components for ensuring waterproofing need to be applied separately to the upper and lower parts of the battery pack, thus increasing the number of components used and complicating the structure.

[0007] Therefore, there is a need to develop cylindrical batteries with a structure in which the anode and cathode terminals are positioned in the same direction, in order to simplify the electrical connection structure of the cylindrical battery. However, in cylindrical batteries with such a structure, multiple components are concentrated in the direction where the anode and cathode terminals are formed. Therefore, structures for venting as internal pressure increases and structures for cutting off current in the event of an overcurrent need to be formed on the side opposite to the direction in which the anode and cathode terminals are located. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The present invention was developed to solve the problems mentioned above. The purpose of the present invention is to enable the cover covering the open part of the battery case to simultaneously perform the functions of an exhaust device and a CID (current interruption device).

[0010] Furthermore, the purpose of this invention is to simplify the electrical connection structure of multiple batteries.

[0011] Furthermore, the purpose of this invention is to ensure sufficient contact area between the components used for electrical connection and the batteries when electrically connecting multiple batteries.

[0012] The technical problems to be solved by the present invention are not limited to those described above. Those skilled in the art can clearly understand other technical problems not mentioned below through the invention description below.

[0013] means of solving technical problems

[0014] To address the aforementioned issues, an embodiment of the present invention provides a battery comprising: an electrode assembly that defines a core and an outer peripheral surface by being wound around a winding shaft with a first electrode, a second electrode, and a separating membrane between them, wherein the first electrode and the second electrode respectively include a first uncoated portion and a second uncoated portion without an active material layer along the winding direction; a battery casing that houses the electrode assembly through an opening formed on one side; a cover having a venting portion that covers the opening and is electrically connected to the battery casing and the first uncoated portion, wherein the venting portion has a thickness thinner than the peripheral region; and a battery terminal that penetrates one surface of the battery casing and is electrically connected to the second uncoated portion.

[0015] The battery casing is electrically connected to the first uncoated portion via the cover.

[0016] The cover has a connecting portion for electrical connection with the first uncoated portion.

[0017] The exhaust section is formed in a closed loop, and the connecting section is located within the closed loop.

[0018] The aforementioned exhaust portion has a groove shape formed on at least one of the outer and inner surfaces of the aforementioned cover.

[0019] The battery terminals are exposed to the outside of the battery case through the closed portion of the battery case located on the opposite side of the open portion.

[0020] The aforementioned battery terminal penetrates the center of the aforementioned blocking portion.

[0021] The aforementioned battery terminals are electrically insulated from the aforementioned battery casing.

[0022] The battery also includes a first current collector combined with the first uncoated portion.

[0023] The first current collector is electrically connected to the cover.

[0024] The first current collector and the cover are electrically connected via lead wire connectors.

[0025] The aforementioned lead connector has a length that is longer than the distance between the aforementioned first current collector and the aforementioned cover.

[0026] The battery also includes a second current collector that is coupled to the second uncoated portion.

[0027] The second current collector is connected to the battery terminal.

[0028] The battery also includes a sealing gasket located between the cover and the battery casing.

[0029] The battery casing has: a rolled edge portion formed by pressing around the outer peripheral surface of the battery casing; and a press-fit portion below the rolled edge portion, which is formed by extending and bending from the end defining the open portion in a manner that surrounds the edge of the cover.

[0030] The aforementioned sealing gasket is located in the area where the aforementioned rolled edge is formed, excluding the area where the aforementioned cover and the aforementioned battery case contact each other.

[0031] The battery casing has: a rolled edge portion formed by pressing around the outer peripheral surface of the battery casing; and a press-fit portion below the rolled edge portion, which is formed by extending and bending from the end defining the open portion in a manner that surrounds the edge of the cover.

[0032] The edge of the first current collector is supported by the rolled edge portion.

[0033] An insulating layer is sandwiched between the edges of the first current collectors that are opposite to each other and the rolled edge of the battery casing.

[0034] The aforementioned insulating layer is an insulating coating formed on the surface of either the first current collector or the rolled edge portion.

[0035] The battery also includes an insulator that covers the lower surface of the electrode assembly opposite to the cover.

[0036] The insulator has a hole at a position corresponding to the hole formed at the winding center of the electrode assembly.

[0037] The first current collector and the cover are electrically connected by a lead connector, and the insulator has a hole for the lead connector to pass through.

[0038] At least a portion of the uncoated portion includes a plurality of slicing sections divided along the winding direction of the electrode assembly, the slicing sections being bundled along the radial direction of the electrode assembly.

[0039] After being bound together, the multiple slices overlap along the aforementioned radial direction to form multiple layers.

[0040] The electrode assembly has a welding target area, which is a region where the number of overlaps of the slices of the first uncoated portion remains constant along the radial direction of the electrode assembly, and the first current collector is bonded to the first uncoated portion in the welding target area.

[0041] At least a portion of the second uncoated portion includes a plurality of slicing sections divided along the winding direction of the electrode assembly, the slicing sections being bundled along the radial direction of the electrode assembly.

[0042] After being bound together, the multiple slices overlap along the aforementioned radial direction to form multiple layers.

[0043] The electrode assembly has a welding target area, which is a region where the number of overlaps of the slices of the second uncoated portion remains constant along the radial direction of the electrode assembly, and the second current collector is bonded to the second uncoated portion in the welding target area.

[0044] The resistance measured between the anode and cathode is less than 4 milliohms.

[0045] The ratio of the diameter to the height of the aforementioned battery is greater than 0.4.

[0046] In addition, a battery pack according to one embodiment of the present invention includes a plurality of batteries according to one embodiment of the present invention.

[0047] Multiple batteries are arranged in a predetermined number of columns, and the outer surfaces of the battery terminals and the closed portions of the battery casing of each battery are arranged facing upwards.

[0048] The aforementioned battery pack includes multiple busbars that connect multiple batteries in series and in parallel, and the multiple busbars are disposed on the upper part of the batteries. Each busbar includes: a main body extending between the battery terminals of adjacent batteries; multiple first busbar terminals extending toward one side of the main body and electrically connected to the battery terminals of the battery located in that side direction; and multiple second busbar terminals extending toward the other side of the main body and electrically connected to the outer surface of the closing portion of the battery casing of the battery located in the other side direction.

[0049] An automobile according to one embodiment of the present invention for solving the above-mentioned problems includes a battery pack as described in one embodiment of the present invention.

[0050] Invention Effects

[0051] According to the present invention, the cover covering the open portion of the battery casing can simultaneously function as an exhaust device and as a CID (current interruption device).

[0052] Furthermore, according to the present invention, multiple batteries can be electrically connected on one side of the battery along its length, thus simplifying the electrical connection structure.

[0053] Furthermore, according to the present invention, the bonding area between the component used for electrical connection and the battery can be sufficiently ensured, thereby reducing resistance and ensuring sufficient bonding strength.

[0054] In addition to the effects described above, the effects of the present invention are not limited to those described above. Other effects not mentioned herein will be clearly understood by those skilled in the art through the following description. Attached Figure Description

[0055] Preferred embodiments of the invention are illustrated in the accompanying drawings, which serve to further explain the technical concept of the invention together with the detailed description of the invention that follows. Therefore, the invention should not be construed as being limited to the scope shown in these drawings.

[0056] Figure 1 This is a diagram showing the appearance of a cylindrical secondary battery according to an embodiment of the present invention.

[0057] Figure 2 This is a cross-sectional view showing the internal structure of a cylindrical secondary battery according to an embodiment of the present invention.

[0058] Figure 3 This is a cross-sectional view showing the lower structure of the battery, illustrating the problems that may occur when the first current collector and the battery casing come into contact in the battery of the present invention.

[0059] Figure 3a and Figure 3b This is a partial cross-sectional view showing the lower structure of a battery according to an embodiment of the present invention.

[0060] Figure 4 This is a diagram showing the bottom surface of a battery according to an embodiment of the present invention.

[0061] Figure 5 This is a conceptual diagram used to illustrate the positional relationship between the connecting part and the venting part provided on the cover of the present invention, as well as the shape of the venting part.

[0062] Figure 6 This is a partial cross-sectional view showing the upper structure of a cylindrical battery according to an embodiment of the present invention.

[0063] Figure 7 This is a diagram showing an electrode assembly with segmented sections.

[0064] Figure 8 and Figure 9 This is a diagram illustrating the uncoated bonding structure between the current collector and electrode assembly used in this invention.

[0065] Figure 10 This is a top top view showing a configuration in which multiple cylindrical batteries are connected in series and parallel using busbars, according to an embodiment of the present invention.

[0066] Figure 11 This is a schematic diagram of a battery pack illustrating an embodiment of the present invention.

[0067] Figure 12 This is a concept diagram of a car illustrating one embodiment of the present invention.

[0068] (Symbol Explanation)

[0069] 5: Cars

[0070] 3: Battery pack

[0071] 2: Assembly shell

[0072] 1: Battery

[0073] 10: Electrode assembly

[0074] C: Winding Center

[0075] 11: First Uncoated Section

[0076] 12: Second uncoated section

[0077] F: Slicing

[0078] 20: Battery casing

[0079] T1: First electrode terminal

[0080] 21: Rolled edge

[0081] 22: Crimping section

[0082] 30: Cover

[0083] 31: Exhaust section

[0084] 40: Battery terminals

[0085] T2: Second electrode terminal

[0086] 50: First collector

[0087] L: Lead wire connector

[0088] 60: Sealing gasket

[0089] 70: Insulating gasket

[0090] 80: Second collector

[0091] 90: Insulator (First Insulator)

[0092] IS: Insulator (Second Insulator)

[0093] CL: Insulating layer Detailed Implementation

[0094] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Before the description, 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 structures shown in the accompanying drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, at the time of application of this invention, there should be various equivalents and modifications that can replace these.

[0096] Furthermore, to aid in understanding the invention, the accompanying drawings are not shown at an actual scale, and the proportional dimensions of some structural elements may be exaggerated. Additionally, the same structural element may be given the same reference numeral in different embodiments.

[0097] The phrase "two comparison objects are identical" means "substantially identical." Therefore, "substantially identical" can include cases with what is considered a low deviation in the field, such as within 5%. Furthermore, "uniformity of a parameter within a specified field" means uniformity from an average perspective.

[0098] Although the terms "first," "second," and several other structural elements are used for narration, these structural elements are clearly not limited by these terms. These terms are only used to distinguish one structural element from others, and unless there is a specific contrary statement, the first structural element can certainly be the second structural element.

[0099] In the instruction manual as a whole, unless otherwise stated otherwise, each structural element may be a single element or a multiple elements.

[0100] The placement of any structure in the "above (or below)" or "above (or below)" of a structural element not only indicates that the arbitrary structure is connected to the upper (or lower) surface of the aforementioned structural element, but also indicates that there are other structures sandwiched between the aforementioned structural element and the arbitrary structure placed on (or below) the aforementioned structural element.

[0101] In addition, when a structural element is described as being "connected", "combined", or "accessed" to other structural elements, the aforementioned structural elements may be directly connected or accessed to each other, but it should be understood that other structural elements are "interspersed" between the structural elements, or that the structural elements are "connected", "combined", or "accessed" through other structural elements.

[0102] Throughout the instruction manual, "A and / or B" means A, B, or A and B unless otherwise stated otherwise, and "C to D" means C and above and D and below unless otherwise stated otherwise.

[0103] Reference Figures 1 to 3b and Figure 6 In one embodiment of the present invention, the battery 1 is, for example, a cylindrical battery. The cylindrical battery 1 includes an electrode assembly 10, a battery casing 20, a cover 30, and battery terminals 40. In addition to the aforementioned components, the cylindrical battery 1 also includes a first current collector 50 and / or a sealing gasket 60 and / or an insulating gasket 70 and / or a second current collector 80 and / or an insulator (first insulator) 90. The present invention is not limited to the shape of the battery and can also be applied to batteries of other shapes, such as various types of batteries.

[0104] The electrode assembly 10 includes a first uncoated portion 11 and a second uncoated portion 12. The electrode assembly 10 includes a first electrode plate having a first polarity, a second electrode plate having a second polarity, and a separation membrane between the first electrode plate and the second electrode plate. The first electrode plate is either an anode plate or a cathode plate, and the second electrode plate is equivalent to an electrode plate having a polarity opposite to that of the first electrode plate.

[0105] The electrode assembly 10 described above, for example, has a jelly-roll shape. That is, the electrode assembly 10 is manufactured by winding up a laminate formed by sequentially stacking a first electrode plate, a separation membrane, and a second electrode plate at least once. Such a jelly-roll type electrode assembly 10 has a winding center hole formed at the winding center C and extending along the height direction (the direction parallel to the Z-axis). In addition, an additional separation membrane is provided on the outer peripheral surface of the electrode assembly 10 for insulation from the battery casing 20.

[0106] The first electrode includes a first conductive material and a first electrode active material formed by coating one or both surfaces of the first conductive material. A first uncoated portion, without the first electrode active material, exists at one end along the width direction (the direction parallel to the Z-axis) of the first conductive material. When the first electrode is in its unfolded state, the first uncoated portion has a shape extending from one end to the other along the length direction of the first electrode. The first uncoated portion 11 serves as a first electrode tab. The first uncoated portion 11 is disposed on one surface of the electrode assembly 10. More specifically, the first uncoated portion 11 is disposed at the lower part in the height direction (the direction parallel to the Z-axis) of the electrode assembly 10 housed within the battery casing 20.

[0107] The second electrode comprises a second conductive material and a second electrode active material formed by coating one or both sides of the second conductive material. An uncoated portion of the second electrode active material exists at the other end along the width direction (the direction parallel to the Z-axis). When the second electrode is in its unfolded state, the uncoated portion has a shape extending from one end to the other along the length direction of the second electrode. The uncoated portion 12 serves as a second electrode tab. The uncoated portion 12 is disposed on another surface of the electrode assembly 10. More specifically, the uncoated portion 12 is disposed at the upper part of the electrode assembly 10 housed within the battery casing 20 in the height direction (the direction parallel to the Z-axis).

[0108] That is, the first uncoated portion 11 and the second uncoated portion 12 extend and protrude in opposite directions along the height direction of the electrode assembly 10 (the direction parallel to the Z-axis), that is, the height direction of the cylindrical battery 1, and expose themselves to the outside of the separation membrane.

[0109] Additionally, refer to Figure 7 At least a portion of the first uncoated portion 11 and / or the second uncoated portion 12 includes a plurality of slabs F divided along the winding direction of the electrode assembly 10. These slabs are then bundled together along the radial direction of the electrode assembly. The bundled slabs overlap to form multiple layers. At this time, the first current collector 50 and / or the second current collector 80, described later, are bonded to the region where the slabs F overlap to form multiple layers.

[0110] Furthermore, the electrode assembly 10 has a welding target area, which is a region where the number of overlapping layers of the slices F of the first uncoated portion 11 and / or the second uncoated portion 12 remains constant along the radial direction of the electrode assembly 10. In such a welding target area, the number of overlapping layers of the slices F is maintained at approximately maximum, thus facilitating the welding of the first current collector 50 to the first uncoated portion 11 and / or the welding of the second current collector 80 to the second uncoated portion 12, described later, within the welding target area. This is to prevent the laser beam from penetrating the first uncoated portion 11 and / or the second uncoated portion 12 and damaging the electrode assembly 10 when the laser output is increased to improve welding quality during laser welding. The first current collector is bonded to the first uncoated portion in the welding target area. Additionally, this is to prevent impurities such as welding spatter from being introduced into the interior of the electrode assembly 10.

[0111] Reference Figures 1 to 3b The battery casing 20, being a generally cylindrical housing with an open portion formed at the bottom, is made of a conductive metal material. The side and top surfaces of the battery casing 20 are integrally formed. The top surface of the battery casing 20, i.e., the outer surface of the closed portion, has a generally flat shape. The battery casing 20 houses the electrode assembly 10 and the electrolyte through an open portion formed on one side in its height direction (the direction parallel to the Z-axis).

[0112] The battery casing 20 has a shape where its lower end is open in the height direction (the direction parallel to the Z-axis) and its upper end is closed. The battery casing 20 has a rolled edge portion 21 and a pressing portion 22 formed at its lower end. The rolled edge portion 21 is formed at the lower part of the electrode assembly 10. The rolled edge portion 21 is formed by pressing the outer peripheral surface of the battery casing 20 inwards. For example, the rolled edge portion 21 prevents the electrode assembly 10, which has a size corresponding to the width (diameter) of the battery casing 20, from detaching through the open portion formed at the lower end of the battery casing 20, and serves as a support for mounting the cover 30. On another side, the rolled edge portion 21 also serves as a support for mounting the first current collector 50. That is, the edge of the first current collector 50 is supported by the rolled edge portion 21.

[0113] The aforementioned crimping portion 22 is formed on the lower part of the rolled edge portion 21. The crimping portion 22 has a shape in which the end of the opening portion defining the battery case 20 below the rolled edge portion 21 extends and bends to surround the edge of the cover 30.

[0114] However, the battery case 20 of the present invention may not have such a rolled edge portion 21 and / or a crimped portion 22. In such cases, the fixing of the electrode assembly 10 and / or the fixing of the cover 30 and / or the sealing of the battery case 20 are achieved, for example, by the additional application of a component serving as a stop portion for the electrode assembly 10 and / or the additional application of a structure for mounting the cover 30 and / or welding between the battery case 20 and the cover 30.

[0115] Furthermore, the battery casing 20 has the same polarity as the downwardly extending first uncoated portion 11. The battery casing 20 is electrically connected to the first uncoated portion 11 via the cover 30. The polarity of the battery casing 20 will be described in more detail later when the cover 30 is explained.

[0116] Reference Figures 2 to 5 The cover 30 covers the opening formed at the lower end of the battery casing 20 and is electrically connected to the battery casing 20 and the first uncoated portion 11. The cover 30 is a component made of a conductive metal material. The cover 30 has an exhaust portion 31 that ruptures to release internal gas as internal pressure increases, and a connection portion P for electrically connecting to the first uncoated portion 11. The cover 30 functions as an exhaust component when internal pressure increases due to an abnormality in the secondary battery in the cylindrical battery 1 of the present invention, and as a current cut-off component when an overcurrent occurs.

[0117] The aforementioned cover 30 is welded to the opening formed at the lower end of the battery case 20. In contrast, the aforementioned cover 30 is fixed to the press-fit portion 22 of the battery case 20 by a sealing gasket 60, described later. Of course, when using the sealing gasket 60, welding can also be used in parallel to further increase the fixing force and reduce resistance.

[0118] The aforementioned cover 30 is electrically connected to the first uncoated portion 11 of the electrode assembly 10. The first uncoated portion 11 of the electrode assembly 10 is directly bonded to the connection portion P of the cover 30. In contrast, the first uncoated portion 11 of the electrode assembly 10 is bonded to the connection portion P of the cover 30 via the first current collector 50 and / or lead connector L, which will be described later.

[0119] The aforementioned venting section 31 corresponds to a region in the cover 30 that is less rigid than the surrounding area. When the venting section 31 is formed by adjusting the thickness of the cover 30, it corresponds to a region in the cover 30 that is thinner than the surrounding area. For example, the venting section 31 may have a groove shape formed on the outer and / or inner surfaces of the cover 30. When the cover 30 is made entirely of the same material, if a particular region is thinner, in the event of an abnormal increase in internal pressure in the battery casing 20, the thinner region may rupture, and gas formed inside may be released through it. Alternatively, the venting section 31 may be formed by using a material with weaker strength and / or melting point compared to the surrounding area.

[0120] As described later, a cylindrical battery 1 according to one embodiment of the present invention has a structure in which a battery terminal 40 is provided in the upper part in the height direction (the direction parallel to the Z-axis), thereby the upper structure is more complex than the lower structure. Therefore, in order to discharge the internal gas by venting, an venting section 31 is formed in the cover 30 constituting the bottom surface of the cylindrical battery 1.

[0121] Furthermore, the aforementioned venting section 31 is continuously formed in a closed loop, and the connecting portion P is located within such a closed loop. That is, the current moving from the first uncoated portion 11 of the electrode assembly 10 through the cover 30 to the battery case 20 must pass through the venting section 31. This is so that the cover 30, in addition to performing the function of a venting component as described above, also functions as a current-cutting component in the event of an overcurrent. When the connecting portion P is located outside the closed loop of the venting section 31, the current path will not pass through the venting section 31, therefore the venting section 31 cannot perform the function of a current-cutting component. Moreover, even if the connecting portion P is located within the loop formed by the venting section 31, as Figure 5 As shown, its ring cannot form a closed loop. If even a part of it has an open shape, the current transmitted from the electrode assembly 10 to the cover 30 will flow through the open area. Therefore, in such a case, the exhaust section 31 cannot perform the function of a current cut-off component.

[0122] Reference Figure 1 , Figure 2 and Figure 6 The battery terminal 40 can pass through a closed portion located on the opposite side of the open portion formed on one side of the battery casing 20. The battery terminal 40 is electrically connected to the second uncoated portion 12 of the electrode assembly 10 within the battery casing 20. The battery terminal 40 can be directly connected to the second uncoated portion 12, or it can be electrically connected to the electrode assembly 10 via the second current collector 80 (described later). The battery terminal 40 is a component made of a conductive metal material. The battery terminal 40 is electrically insulated from the battery casing 20.

[0123] The insulation between the battery terminal 40 and the battery casing 20 is achieved in various ways. For example, insulation can be achieved by applying an insulating gasket 70. Alternatively, insulation can be achieved by applying an insulating coating to at least a portion of the battery terminal 40 and / or the battery casing 20. Another example is that insulation can be achieved by firmly fixing the battery terminal 40 to the battery casing 20 in a way that keeps them separated, without applying an insulating coating or other such treatment, or without using additional components.

[0124] The aforementioned battery terminal 40 penetrates approximately the center of the upper surface (the surface parallel to the XY plane) of the battery casing 20. At least a portion of the portion of the battery terminal 40 embedded inside the battery casing 20 is bonded to the second uncoated portion 12 or the second current collector 80 of the electrode assembly 10 by welding or the like. Furthermore, at least a portion of the portion of the battery terminal 40 embedded inside the battery casing 20 is twisted toward the upper surface of the battery casing 20 to achieve riveting. That is, the battery terminal 40 of the present invention is a rivet-type terminal that penetrates the battery casing 20 and is bonded to the inner surface of the battery casing 20 by riveting.

[0125] Thus, in the cylindrical battery 1 of the present invention, the outer surface of the upper surface of the battery casing 20, which has the same polarity as the first uncoated portion 11, i.e., the outer surface of the closed portion, is used as the first electrode terminal T1, and the battery terminal 40, which has the same polarity as the second uncoated portion 12, is used as the second electrode terminal T2. Therefore, the cylindrical battery 1 of the present invention has a structure in which a pair of electrode terminals T1 and T2 are provided on one side in the height direction, thereby realizing a structure in which all electrical connection components are concentrated in one direction when multiple cylindrical batteries 1 are electrically connected. Such a structure simplifies the structure in the manufacture of battery packs, thereby improving productivity and energy density.

[0126] Furthermore, in the cylindrical battery 1 of the present invention, the entire area of ​​the generally flat upper surface of the battery casing 20, except for the area occupied by the battery terminal 40, is used as the first electrode terminal T1. Therefore, when components such as busbars used to achieve electrical connection are attached to the first electrode terminal T1, sufficient contact area can be ensured, thereby facilitating connection even when using large-area busbars and reducing resistance at the contact point.

[0127] Reference Figure 2 and Figure 3bThe first current collector 50 can be attached to the lower end of the electrode assembly 10 in the height direction (the direction parallel to the Z-axis). The first current collector 50 is attached to the first uncoated portion 11. The first current collector 50 is electrically connected to the cover 30. That is, when the cylindrical battery 1 is equipped with the first current collector 50, the first uncoated portion 11 of the electrode assembly 10 is electrically connected to the cover 30 via the first current collector 50. The first current collector 50 is electrically connected to the cover 30, for example, via a lead connector L. The lead connector L can be a component integrally formed with the first current collector 50, or it can be formed separately with one side attached to the first current collector 50 and the other side attached to the cover 30. (Refer to...) Figure 2 and Figure 3 , Figure 5 The first current collector 50 or lead connector L is connected to the connection part P of the cover 30, and the connection part P is located within the closed loop formed by the venting part 31. This is so that the current passing through the first current collector 50 and the battery case 20 must pass through the venting part 31, and in the event of an overcurrent, the overcurrent is quickly cut off through the venting part 31.

[0128] Preferably, the lead connector L has a length longer than the distance between the first current collector 50 and the cover 30. This is to prevent the breakage pressure of the exhaust section 31 from exceeding the design value due to insufficient extension length of the lead connector L.

[0129] Furthermore, the first current collector 50 has a current collector hole 50a formed at a position corresponding to the hole formed in the winding center C of the electrode assembly 10. The current collector hole 50a communicates with the hole formed in the winding center C of the electrode assembly 10, thereby allowing the insertion of a tool or the passage of a laser beam through the winding center hole of the electrode assembly 10 to weld the second current collector 80 and the battery terminal 40 located opposite the first current collector 50. The current collector hole 50a also serves as a channel for electrolyte injection.

[0130] Reference Figures 2 to 3b The aforementioned sealing gasket 60 is a component used to improve the sealing performance achieved by the cover 30, which covers the lower opening portion of the battery housing 20 in the height direction (parallel to the Z-axis). Considering this function, an elastic material is used as the material for the sealing gasket 60. A portion of the sealing gasket 60 is located between the battery housing 20 and the cover 30. As mentioned above, the battery housing 20 needs to contact the cover 30 to achieve electrical connection. Therefore, the sealing gasket 60 should not completely sever the contact between the battery housing 20 and the cover 30. For this purpose, the area formed by the pressing portion 22 of the battery housing 20 is located between the cover 30 and the battery housing 20, and also in the remaining area excluding the area where the cover 30 contacts the battery housing 20.

[0131] Reference Figure 1 , Figure 2 and Figure 6 The aforementioned insulating gasket 70 is positioned between the battery casing 20 and the battery terminal 40 to prevent the battery casing 20 and the battery terminal 40, which have opposite polarities, from contacting each other. Furthermore, the insulating gasket 70 prevents a decrease in the sealing performance of the battery casing 20 due to the use of the battery terminal 40. Considering these functions, a material with both insulating and elastic properties can be used as the material for the insulating gasket 70. A portion of the insulating gasket 70 bends along with the flange of the battery terminal 40 towards the inner side of the closed portion of the battery casing 20 during the riveting of the battery terminal 40. Thus, a portion of the insulating gasket 70 is positioned between the flange of the battery terminal 40 and the inner side of the closed portion of the battery casing 20.

[0132] Reference Figure 6 The second current collector 80 is attached to the upper end of the electrode assembly 10 in the height direction (the direction parallel to the Z-axis). Thus, the second current collector 80 is attached to the second uncoated portion 12. The second current collector 80 is electrically connected to the battery terminal 40. That is, when the cylindrical battery 1 is equipped with the second current collector 80, the second uncoated portion 12 of the electrode assembly 10 is electrically connected to the battery terminal 40 via the second current collector 80. The second current collector 80 is directly attached to the battery terminal 40. In contrast, the second current collector 80 is attached to the first current collector 50 (see reference...). Figure 3 Similarly, it can also be electrically connected to the battery terminal 40 via an additional component such as a lead connector (not shown). In this case, the lead connector can be a component integrally formed with the second current collector 80, or it can be formed separately from the second current collector 80 with one side attached to the second current collector 80 and the other side attached to the battery terminal 40.

[0133] in addition, Figure 8 and Figure 9 The combined structure of the current collector and electrode assembly used in this invention is shown.

[0134] First, refer to Figure 8 The second current collector 80 is bonded to a bonding surface formed by bending the end of the second uncoated portion 12 in the opposite direction to the second current collector 80. The bonding between the second uncoated portion 12 and the second current collector 80 is achieved, for example, by laser welding. This laser welding can be achieved either by melting the base material of the second current collector 80, or by sandwiching solder between the second current collector 80 and the second uncoated portion 12. In this case, the solder preferably has a lower melting point than both the second current collector 80 and the second uncoated portion 12.

[0135] Reference Figure 9The second current collector 80 is bonded to the bonding surface formed by bending the end of the second uncoated portion 12 in a direction parallel to the second current collector 80. The bending direction of the second uncoated portion 12 is, for example, towards the winding center C of the electrode assembly 10.

[0136] When the first uncoated portion 11 and / or the second uncoated portion 12 have such a bent shape, the space occupied by the first uncoated portion 11 and / or along the height direction (the direction parallel to the Z-axis) of the electrode assembly 10 is reduced, that is, the height (length in the Z-axis direction) of the electrode assembly 10 is reduced, which can improve the energy density.

[0137] Reference Figure 6 The insulator 90 is located between the upper end of the electrode assembly 10 and the inner side of the battery case 20, or between the second current collector 80, which is attached to the upper part of the electrode assembly 10, and the inner side of the battery case 20. The insulator 90 is shaped to extend in a manner that additionally covers the side of the electrode assembly 10. The insulator 90 prevents contact between the second uncoated portion 12 and the battery case 20, or between the second current collector 80 and the battery case 20.

[0138] When the cylindrical battery 1 of the present invention has an insulator 90 disposed on the upper part of the electrode assembly 10, the battery terminal 40 passes through the insulator 90 inside the battery case 20 and is connected to the second current collector 80 or the second uncoated portion 12.

[0139] Additionally, as in the present invention Figure 3 As shown, when the contact between the first current collector 50 and the battery case 20 is directly formed, the overcurrent cut-off component of the cover 30 of the present invention can be performed. For the cover 30 to perform the overcurrent cut-off component function, the electrical connection between the first current collector 50 and the battery case 20 should be achieved through the cover 30. This is because the current transmitted from the first current collector 50 can be cut off by the venting portion 31 formed in the cover 30, which is thinner than the surrounding area, thus interrupting the overcurrent.

[0140] Reference Figure 3a and Figure 3b To prevent the first current collector 50 and the battery casing 20 from directly contacting each other, an insulating layer CL and / or an insulator (second insulator) IS are sandwiched between the first current collector 50 and the battery casing 20.

[0141] The aforementioned insulating layer CL is located between the first current collector 50 and the rolled edge portion 21 of the battery casing 20, which are opposite to each other. The aforementioned insulating layer CL is, for example, an insulating coating formed on any one of the surfaces of the first current collector 50 and / or the rolled edge portion 21.

[0142] The aforementioned insulator (second insulator) covers the lower surface of the electrode assembly 10 opposite to the cover 30. The insulator IS may also have a shape that extends between the inner surfaces of the opposing first uncoated portion 11 and the sidewall portion of the battery casing 20 for reliable insulation. The insulator IS has a hole formed at a position corresponding to the hole at the winding center C of the electrode assembly 10. This hole serves as a channel for injecting electrolyte and / or for inserting tools or allowing a laser beam to pass through for welding the second current collector 80 to the battery terminal 40. Additionally, the insulator IS has a hole through which the lead connector L for electrically connecting the first current collector 50 and the cover 30 passes.

[0143] The cylindrical battery 1 of the present invention described above has a structure that minimizes resistance due to the increased welding area caused by the formation of the bonding surface formed by bending along the uncoated portions 11 and 12, and the increased welding area caused by the bonding busbar using the outer surface of the closed portion of the battery case 20. The AC resistance of the cylindrical battery 1, measured by a resistance meter, between the anode and cathode, and between the battery terminal 40, T2 and its surrounding generally flat surface T1, is approximately 0.5 milliohms to 4 milliohms, suitable for rapid charging, preferably approximately 1 milliohm to 4 milliohms.

[0144] Preferably, the cylindrical battery is, for example, a cylindrical battery with a shape factor (defined as the ratio of the diameter of the cylindrical battery to its height, i.e., the ratio of the diameter Φ to the height H) that is approximately greater than 0.4.

[0145] Here, the shape factor refers to the value representing the diameter and height of the cylindrical battery. Preferably, the diameter of the cylindrical battery is approximately 40 mm to 50 mm, and the height is approximately 60 mm to 130 mm. One embodiment of the cylindrical battery of the present invention may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the shape factor values, the first two digits represent the diameter of the battery, and the remaining digits represent the height of the battery.

[0146] When using capless electrode assemblies in cylindrical batteries with a shape factor ratio exceeding 0.4, the stress applied in the radial direction when bending the uncoated portion is large, easily leading to tearing of the uncoated portion. Furthermore, to ensure sufficient weld strength and reduce resistance when welding current collectors to the bending surface region of the uncoated portion, the number of layers of the uncoated portion in the bending surface region should be sufficiently increased. These requirements can be achieved through the electrodes and electrode assemblies of embodiments (modified examples) of the present invention.

[0147] One embodiment of the present invention is a battery that is approximately cylindrical, with a diameter of approximately 46 mm, a height of approximately 110 mm, and a shape factor of approximately 0.418.

[0148] Another embodiment of the battery is an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor of approximately 0.640.

[0149] Another embodiment of the battery is an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of approximately 0.418.

[0150] Another embodiment of the battery is an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of approximately 0.600.

[0151] Another embodiment of the battery is an approximately cylindrical battery with a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of approximately 0.575.

[0152] Conventionally, batteries with a form factor ratio of approximately 0.4 or less have been used. Specifically, 1865 and 2170 batteries have been used, for example. In the case of an 1865 battery, its diameter is approximately 18 mm, its height is approximately 65 mm, and its form factor ratio is approximately 0.277. In the case of a 2170 battery, its diameter is approximately 21 mm, its height is approximately 70 mm, and its form factor ratio is approximately 0.300.

[0153] Reference Figure 10 Multiple cylindrical batteries 1 are connected in series and in parallel at the top of the cylindrical batteries 1 via a bus 150. The number of cylindrical batteries 1 can be increased or decreased depending on the capacity of the battery pack.

[0154] In each cylindrical battery 1, the battery terminals 50 and T2 are anodes, and the outer surface T1 of the closed portion of the battery casing 20 is cathode. Of course, the opposite is also possible.

[0155] Preferably, the plurality of cylindrical batteries 1 are arranged in a plurality of columns and rows. A column is a vertical direction relative to the ground, and a row is a horizontal direction relative to the ground. Furthermore, to maximize space efficiency, a closest packing structure can be configured. The closest packing structure is formed when the centers of the battery terminals 50 exposed to the outside of the battery casing 20 are connected to each other, forming an equilateral triangle. Preferably, the busbar 150 is disposed on the upper part of the plurality of cylindrical batteries 1, more preferably between adjacent columns. Alternatively, the busbar 150 can be disposed between adjacent rows.

[0156] Preferably, the busbar 150 connects the batteries 1 arranged in the same column in parallel, and connects the cylindrical batteries 1 arranged between two adjacent columns in series.

[0157] Preferably, the busbar 150 includes a main body 151, a plurality of first busbar terminals 152 and a plurality of second busbar terminals 153 for series and parallel connection.

[0158] The aforementioned main body 151 extends between the battery terminals of adjacent cylindrical batteries 1, preferably between rows of cylindrical batteries 1. Alternatively, the aforementioned main body 151 extends along the rows of cylindrical batteries 1 and bends regularly in a Z-shape.

[0159] Multiple first busbar terminals 152 protrude from one side of the main body 151 toward the battery terminals 50 of each cylindrical battery 1 and are electrically connected to the battery terminals 50. The electrical connection between the first busbar terminals 152 and the battery terminals 50 can be achieved by laser welding, ultrasonic welding, or the like. Additionally, multiple second busbar terminals 153 protrude from the other side of the main body 151 and are electrically connected to the outer surface T1 of the closed portion of the battery casing 20 of each cylindrical battery 1. The electrical connection between the second busbar terminals 153 and the outer surface T1 can be achieved by laser welding, ultrasonic welding, or the like.

[0160] Preferably, the main body 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 are constituted by a conductive metal plate. The metal plate is, for example, an aluminum plate or a copper plate, but the present invention is not limited thereto. In a modified example, the main body 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 are manufactured as individual pieces and then joined together by welding or the like.

[0161] In the cylindrical battery 1 of the present invention, the outer surface T1 of the closed portion of the battery terminal 50 having an anode and the battery case 20 having a cathode is located in the same direction, so the electrical connection of the cylindrical battery 1 can be easily realized by using the bus 150.

[0162] In addition, the outer surface T1 of the battery terminal 50 and the closed portion of the battery case 20 of the cylindrical battery 1 has a large area, so the connection area of ​​the bus 150 can be sufficiently ensured to sufficiently reduce the resistance of the battery pack including the cylindrical battery 1.

[0163] Additionally, refer to Figure 11 In one embodiment of the present invention, the battery pack 3 includes a secondary battery assembly electrically connected to a plurality of cylindrical batteries 1 as described above in one embodiment of the present invention, and a housing 2 for housing it. Regarding the electrical connection structure of the plurality of batteries 1 implemented via a busbar, it has been previously referred to... Figure 10 As illustrated above, components such as cooling units and power terminals are omitted from the illustrations for convenience.

[0164] Reference Figure 12In one embodiment of the present invention, the vehicle 5 is, for example, an electric vehicle, including a battery pack 3 according to one embodiment of the present invention. The vehicle 5 operates by receiving power from the battery pack 3 according to one embodiment of the present invention.

[0165] While the present invention has been described above with limited embodiments and accompanying drawings, it is not limited thereto. Those skilled in the art should be able to make various modifications and variations within the scope of the technical concept of the present invention and the equivalent scope of the claims described below.

Claims

1. A battery comprising: An electrode assembly that defines a core and an outer peripheral surface by winding a first electrode, a second electrode and a separation membrane between them around a winding axis, wherein each of the first electrode and the second electrode includes a first uncoated portion and a second uncoated portion along the winding direction without an active material layer. A battery case that houses the electrode assembly through an opening formed on one side thereof, the battery case including a closing portion located on the opposite side of the opening; A cover having a venting portion covering the open portion and electrically connected to the battery casing and the first uncoated portion, wherein the venting portion is configured to have a thickness thinner than the surrounding area; and A battery terminal, configured to pass through the closure portion and be electrically connected to the second uncoated portion. The battery casing is electrically connected to the first uncoated portion via the cover.

2. The battery according to claim 1, wherein, The exhaust section is formed in a closed loop continuous manner.

3. The battery according to claim 1, wherein, The exhaust portion has a groove shape formed on at least one of the outer and inner surfaces of the cover.

4. The battery according to claim 1, wherein, The battery terminal is inserted into the interior of the battery casing to be electrically connected to the second uncoated portion.

5. The battery according to claim 1, wherein, The battery terminals are electrically insulated from the battery casing.

6. The battery according to claim 1, The battery also includes a first current collector combined with the first uncoated portion.

7. The battery according to claim 6, wherein, The first current collector is electrically connected to the cover.

8. The battery according to claim 1, The battery also includes a second current collector that is coupled to the second uncoated portion.

9. The battery according to claim 8, wherein, The second current collector is connected to the battery terminal.

10. The battery according to claim 8, wherein, The second current collector is bonded to the mating surface formed by bending the second uncoated portion.

11. The battery of claim 1, further comprising a second current collector coupled to the second uncoated portion. wherein, The second current collector is bonded to the mating surface formed by bending the second uncoated portion. The battery terminal passes through the closed portion of the battery casing and is inserted into the interior of the battery casing to be electrically connected to the second current collector.

12. The battery according to claim 6, wherein, At least a portion of the first uncoated portion includes a plurality of slices divided along the winding direction of the electrode assembly, and The multiple slices are bundled together along the radial direction of the electrode assembly.

13. The battery according to claim 12, wherein, The multiple segments after being bound together overlap in multiple layers along the radial direction.

14. The battery according to claim 13, wherein, The first current collector overlaps with the multiple sub-slices after the binding to form a multi-layered region.

15. The battery according to claim 8, wherein, At least a portion of the second uncoated portion includes a plurality of slices divided along the winding direction of the electrode assembly, and The multiple slices are bundled together along the radial direction of the electrode assembly.

16. The battery according to claim 15, wherein, The multiple segments after being bound together overlap in multiple layers along the radial direction.

17. The battery according to claim 16, wherein, The second current collector overlaps with the multiple sub-slices after the binding to form a multi-layered region.

18. The battery according to claim 1, wherein, The side surface of the battery casing and the closure portion are integrally formed.

19. A battery pack comprising a plurality of batteries according to any one of claims 1 to 18.

20. An automobile comprising the battery pack according to claim 19.

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