Electrode assembly, battery cell, and battery module including battery cell

Abstract

An electrode assembly according to an embodiment of the present invention includes: a positive electrode; a negative electrode; a separator disposed between the positive and negative electrodes; and an electrode lead connected to the positive or negative electrode, wherein the electrode lead includes: a first conductor portion; and a second conductor portion connected to the first conductor portion. In the electrode assembly according to an embodiment of the present invention, the first conductor portion is made of a first metal, and the second conductor portion is made of a second metal different from the first metal, thereby enabling the selection of a lead material that is relatively unaffected by the redox potential of the battery, thereby improving heat dissipation characteristics by using a lead material with high thermal conductivity.

Description

Technical Field

[0001] This disclosure relates to electrode leads, electrode assemblies, battery cells including electrode assemblies, and battery modules including battery cells, and more specifically, to electrode leads, electrode assemblies, battery cells, and battery modules having improved heat dissipation characteristics. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged, and are used not only in portable devices, but also in electric vehicles (EVs), hybrid electric vehicles (HEVs), and other vehicles powered by electric drive sources.

[0003] Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. These modular rechargeable battery cells, or unitary battery cells, operate at voltages ranging from approximately 2.5 V to 4.6 V. Therefore, when a higher output voltage is required, multiple battery cells can be connected in series to construct a battery pack. Alternatively, multiple battery cells can be connected in parallel to construct a battery pack, depending on the required charge / discharge capacity. Thus, the number of battery cells included in a battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0004] When constructing a battery pack by connecting multiple battery cells in series or parallel, typically, a battery module comprising at least one battery cell, preferably multiple battery cells, is first constructed, and then a battery pack is constructed by adding other components while using at least one battery module. Here, a battery module refers to a component in which multiple battery cells are connected in series or parallel, and a battery pack refers to a component in which multiple battery modules are connected in series or parallel to improve capacity, output, etc.

[0005] During charging and discharging by applying a large current to the battery cells that make up the battery module, there is a problem that the temperature of the battery leads rises to greater than or equal to 80°C. Although the temperature rise can be mitigated by improving heat dissipation characteristics by using lead materials with high thermal conductivity, the materials that can be used as leads are limited by the redox potential associated with battery characteristics. Summary of the Invention Technical issues

[0006] This disclosure aims to provide an electrode lead, an electrode assembly, and a battery cell including the electrode lead and the electrode assembly, which can improve heat dissipation characteristics by using a lead material with high thermal conductivity. Technical solution

[0007] An exemplary embodiment of this disclosure provides an electrode assembly including: a positive electrode; a negative electrode; a separator disposed between the positive and negative electrodes; and an electrode lead connected to the positive or negative electrode, wherein the electrode lead includes a first conductor portion and a second conductor portion connected to the first conductor portion.

[0008] In addition, the first conductor portion is made of a first metal.

[0009] In addition, the electrode leads are connected to the positive terminal.

[0010] Alternatively, the first metal could be aluminum.

[0011] In addition, the first conductor portion of the electrode lead is connected to the positive terminal contact of the positive electrode.

[0012] In addition, the second conductor portion is made of a second metal that is different from the first metal.

[0013] Alternatively, the second metal can be copper or nickel-plated copper.

[0014] In addition, the second conductor portion is connected to the first conductor portion in the longitudinal direction.

[0015] Additionally, the first conductor portion includes a groove in a connecting surface connected to the second conductor portion, and the second conductor portion includes a connecting protrusion in a connecting surface connected to the first conductor portion, the connecting protrusion being connected to the groove.

[0016] In addition, the first conductor portion and the second conductor portion each have a wavy connecting surface extending along their width direction.

[0017] In addition, the first conductor portion and the second conductor portion each have a serrated connecting surface extending along their width direction.

[0018] Additionally, the first conductor portion includes a connecting protrusion located on a connecting surface connected to the second conductor portion, and the second conductor portion includes a groove located on a connecting surface connected to the first conductor portion, with the connecting protrusion connected to the groove.

[0019] Another exemplary embodiment of this disclosure provides a battery cell including: an electrode assembly; and a battery case configured to house the electrode assembly, wherein the electrode assembly includes: a positive electrode; a negative electrode; a separator disposed between the positive and negative electrodes; and an electrode lead connected to the positive or negative electrode, and the electrode lead includes a first conductor portion and a second conductor portion connected to the first conductor portion.

[0020] In addition, the first conductor portion of the electrode lead is arranged inside the battery box.

[0021] In addition, the electrode assembly also includes a lead film configured to cover the connection surface of the first conductor portion and the second conductor portion. Beneficial effects

[0022] According to exemplary embodiments of this disclosure, electrode leads, electrode assemblies, and battery cells including electrode leads and electrode assemblies can improve heat dissipation characteristics by using lead materials with high thermal conductivity.

[0023] In addition, by using different materials to connect the lead structure, lead materials that are relatively unaffected by redox potential can be selected.

[0024] In addition, by changing only the material without changing the lead thickness, the variation in battery manufacturing process parameters can be minimized. Attached Figure Description

[0025] Figure 1 This is a perspective view of a battery module according to an exemplary embodiment of the present disclosure.

[0026] Figure 2 This is an exploded perspective view of a battery module according to an exemplary embodiment of the present disclosure.

[0027] Figure 3 This is a perspective view of a terminal busbar according to an exemplary embodiment of the present disclosure.

[0028] Figure 4 This is a perspective view of the insulating cover and end plate in an exemplary embodiment of this disclosure.

[0029] Figure 5 This is a plan view of a battery cell in an exemplary embodiment of this disclosure.

[0030] Figure 6 This is a view showing the interior of a pouch-type battery cell in an exemplary embodiment of this disclosure.

[0031] Figure 7 This is a view illustrating an electrode assembly in an exemplary embodiment of this disclosure.

[0032] Figure 8 This is a plan view of the electrode leads in an exemplary embodiment of this disclosure.

[0033] Figure 9 yes Figure 8 Side view of the electrode leads.

[0034] Figure 10 This is a side view of an electrode lead in another exemplary embodiment of this disclosure.

[0035] Figure 11 This is a plan view of the electrode leads in yet another exemplary embodiment of this disclosure.

[0036] Figure 12 This is a plan view of the electrode leads in yet another exemplary embodiment of this disclosure.

[0037] Figure 13 This is a view illustrating a battery pack according to an exemplary embodiment of the present invention.

[0038] Figure 14 This is a perspective view of a vehicle equipped with a battery pack according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0039] The advantages and features of this disclosure, as well as the methods for achieving these advantages and features, will become clear from the following detailed description of exemplary embodiments in conjunction with the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed below, but can be implemented in various different forms. Exemplary embodiments are provided merely to complete the disclosure of this invention and to allow those skilled in the art to fully understand the scope of this disclosure. This disclosure is defined only by the scope of the claims. Therefore, in some exemplary embodiments, well-known process steps, well-known apparatus structures, and well-known techniques are not specifically described to avoid obscuring the interpretation of this disclosure. Throughout the specification, the same reference numerals denote the same elements.

[0040] In the accompanying drawings, the thickness of layers and regions is exaggerated for clarity. Throughout the specification, the same reference numerals are assigned to the same elements. When an element such as a layer, film, region, plate, etc., is referred to as being "on top of" another element, it may be "directly" located "on" the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" located "on" another element, this may mean that no intermediate elements are present. Additionally, when an element such as a layer, film, region, plate, etc., is referred to as being "below" another element, it may be "directly" located "below" the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" located "below" another element, this may mean that no intermediate elements are present.

[0041] The electrode leads, electrode assemblies, battery cell 110, and battery module 1000 according to preferred exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] Figure 1 This is a perspective view of a battery module according to an exemplary embodiment of the present disclosure. Figure 2 This is an exploded perspective view of a battery module according to an exemplary embodiment of the present disclosure. Figure 3 This is a perspective view of a terminal busbar according to an exemplary embodiment of this disclosure. Figure 4 This is a perspective view of the insulating cover and end plate in an exemplary embodiment of this disclosure. Figure 5 This is a plan view of a battery cell according to an exemplary embodiment of this disclosure. Figure 6 This is a view showing the interior of a pouch-type battery cell in an exemplary embodiment of this disclosure. Figure 7 This is a view illustrating an electrode assembly in an exemplary embodiment of this disclosure. Figure 8 This is a plan view of the electrode leads in an exemplary embodiment of this disclosure. Figure 9 yes Figure 8 A side view of the electrode leads, and Figure 10 This is a side view of an electrode lead in another exemplary embodiment of this disclosure.

[0043] A battery module 1000 according to an exemplary embodiment of the present disclosure may include a battery cell stack 100 in which a plurality of battery cells 110 are stacked, a module box 200 for housing the battery cell stack 100, a busbar frame 300 positioned on one surface and / or another surface of the battery cell stack 100, an insulating cover 500 positioned outside the busbar frame 300, and an end plate 400 positioned outside the insulating cover 500.

[0044] The battery cell stack 100 can be composed of multiple battery cells 110 stacked in one direction, and the multiple battery cells 110 can be electrically connected. The stacking direction of the multiple battery cells 110 can correspond to... Figure 2 The X-axis direction (or -X-axis direction) in the middle.

[0045] The direction from the front surface of the battery cell stack 100 toward the rear surface, or the opposite direction, can be defined as the longitudinal direction of the battery cell stack 100, and can correspond to the Y-axis direction in the figure. Additionally, the direction from the upper surface of the battery cell stack 100 toward the lower surface, or the opposite direction, can be defined as the width direction of the battery cell stack 100, and can be the Z-axis direction in the figure.

[0046] The longitudinal direction of the battery cell stack 100 can be substantially the same as the longitudinal direction of the battery cell 110. The electrode leads 121 and 122 of the battery cell 110 can be positioned on the front and rear surfaces of the battery cell stack 100, and the busbars 310 and 320 of the battery module 1000 can be arranged close to the front and rear surfaces of the battery cell stack 100 to facilitate electrical connection with the electrode leads 121 and 122. The battery cell 110 will be described below.

[0047] The module box 200 can be used to protect the battery cell stack 100 and the electrical components connected to the battery cell stack from external physical impacts, and can house the battery cell stack 100 and the electrical components within the internal space of the module box 200.

[0048] The structure of module box 200 can vary and can be, for example, a single-frame structure. Here, a single frame can refer to a metal plate having an integrally formed upper surface, lower surface, and two side surfaces. The single frame can be manufactured by extrusion molding. As another example, the structure of module box 200 can be a structure in which a U-shaped frame and a top plate 201 are connected. In the case of a structure in which the U-shaped frame and the top plate 201 are connected, the structure of module box 200 can be formed by connecting the top plate 201 to the upper part of the U-shaped frame, which is a metal plate that is connected or integral with the lower plate and the two side surfaces, and each frame or plate can be manufactured by pressing. In addition, besides a single frame or a U-shaped frame 210, the structure of module box 200 can be configured as an L-shaped frame, and can also be configured as various other forms not described in the foregoing examples.

[0049] The module box 200 can be configured to be open in the longitudinal direction of the battery cell stack 100. The front and rear surfaces of the battery cell stack 100 may not be covered by the module box 200. The electrode leads 121 and 122 of the battery cell 110 may also not be covered by the module box 200. The front and rear surfaces of the battery cell stack 100 may be covered by the busbar frame 300, end plate 400, busbars 310 and 320, etc., as described below. This arrangement protects the front and rear surfaces of the battery cell stack 100 from external physical impacts.

[0050] Compression pad 150 can be positioned between one of the inner surfaces of the battery cell stack 100 and the module box 200.

[0051] The compression pad 150 can be arranged to face the outermost battery cell 110 in the X-axis direction of the battery cell stack 100 in the figure.

[0052] Alternatively, a thermally conductive resin can be injected between the inner surfaces of the battery cell stack 100 and the module box 200, and a thermally conductive resin layer can be formed between one of the inner surfaces of the battery cell stack 100 and the module box 200 by the injected thermally conductive resin. In this case, the thermally conductive resin layer can be positioned on the Z-axis of the battery cell stack 100, and can be formed between the lower plate of the battery cell stack 100 and the module box 200 positioned on the -Z-axis.

[0053] The busbar frame 300 is positioned on one surface of the battery cell stack 100 and may cover one surface of the battery cell stack 100, while guiding the connection between the battery cell stack 100 and an external device. Specifically, the busbar frame 300 may be positioned on the front or rear surface of the battery cell stack 100 as shown, or it may be positioned on the upper, lower, or side surface. At least one of the busbars 310 and 320 and the module connector may be mounted on the busbar frame 300. Figure 2 As shown, one surface of the busbar frame 300 can be connected to one or another surface of the battery cell stack 100, and the other surface of the busbar frame 300 can be connected to busbars 310 and 320.

[0054] The busbar frame 300 may include an electrically insulating material. The busbar frame 300 may limit contact between the busbars 310 and 320 and the battery cell 110 except for the portions where they are connected to the electrode leads 121 and 122, and may prevent electrical short circuits.

[0055] The busbar frame 300 can be positioned on each of the battery cell stack 100 on one side and the other side.

[0056] Busbars 310 and 320 can be mounted on one surface of the busbar frame 300 and can be used to electrically connect the battery cell stack 100 or the battery cell 110 to external device circuitry. Multiple busbars 310 and 320 can be arranged and protected from external impacts by being positioned between the battery cell stack 100 or the busbar frame 300 and the end plate 400, and their durability deterioration due to external moisture can be minimized.

[0057] Busbars 310 and 320 can be electrically connected to the battery cell stack 100 via electrode leads 121 and 122 of the battery cell 110.

[0058] Specifically, the electrode leads 121 and 122 of the battery cell 110 can be bent and connected to the busbars 310 and 320 after passing through the lead slits formed in the busbar frame 300. The battery cells 110 constituting the battery cell stack 100 can be connected in series or in parallel via the busbars 310 and 320.

[0059] Busbars 310 and 320 may include a terminal busbar 320 for electrically connecting one battery module 1000 to another battery module 1000. At least a portion of the terminal busbar 320 may be exposed outside the end plate 400 for connection to the other battery module 1000, and the end plate 400 may be provided with a terminal opening 410 for this purpose.

[0060] One end portion (second portion 322) of the terminal busbar 320 can be exposed through the opening portion 510 of the insulating cover 500 and the terminal opening portion 410 of the end plate 400.

[0061] like Figure 3 As shown, the terminal busbar 320 may include a first portion 321 of electrode leads 121, 122 connected to the battery cell 110 and a second portion 322 exposed to the outside through the terminal opening portion 410. Additionally, the terminal busbar 320 may also include a bent portion 323 formed between the first portion 321 and the second portion 322.

[0062] In the terminal busbar 320, the first portion 321 can be connected to the second portion 322 via a bent portion 323, and one surface of the first portion 321 and one surface of the second portion 322 can be perpendicular to each other. That is, by forming a bent portion 323 on the terminal busbar 320, the second portion 322 protrudes and sits on the sitting portion 530 of the insulating cover 500, and the second portion 322 can be electrically connected to an intermediate busbar (not shown). A connecting hole 322a is formed in the second portion 322, which constitutes one end portion of the terminal busbar 320, and the second portion 322 of the terminal busbar 320 is fixed by a retaining pin (not shown) inserted into the connecting hole 322a.

[0063] End plate 400 can be used to protect the battery cell stack 100 and electrical components connected to the battery cell stack from external physical impacts by covering the open surface of the module box 200. For this purpose, end plate 400 can be made of a material with a predetermined strength and can include metal or plastic materials such as aluminum.

[0064] Terminal openings 410 may be formed in end plate 400. Terminal openings 410 may be arranged on both sides of end plate 400. A portion of insulating cover 500 and one end portion (second portion 322) of terminal busbar 320 may be exposed through terminal openings 410.

[0065] The connector opening can be positioned between the terminal openings 410 arranged on both sides of the end plate 400, and the module connector can be exposed to the outside through the connector opening.

[0066] End plate 400 can be connected to module box 200 and simultaneously cover busbar frame 300 or busbars 310 and 320 located on one surface of battery cell stack 100. Each corner of end plate 400 can be connected to the corresponding corner of module box 200 by welding, bolting, hooking, etc.

[0067] End plates 400 can be positioned on one and another surface of module box 200 to cover the two surfaces of battery cell stack 100, respectively. In this exemplary embodiment, an example is shown in which end plates 400 are positioned on the front and rear surfaces of module box 200.

[0068] Additionally, an insulating cover 500 for electrical insulation can be disposed between the end plate 400 and the busbar frame 300. That is, the busbar frame 300, the insulating cover 500, and the end plate 400 can be sequentially positioned outward from the battery cell stack 100. Like the end plate 400, multiple busbar frames 300 and insulating covers 500 can each be provided.

[0069] The insulating cover 500 may include an electrically insulating material and may prevent the busbars 310 and 320 from contacting the end plate 400.

[0070] The insulating cover 500 may include an opening portion 510 and a seating portion 530. The opening portion 510 may be arranged on each of the two sides of the upper portion of the insulating cover 500, and one end portion (second portion 322) of the terminal busbar 320 may be exposed through the opening portion 510.

[0071] The connector opening can be positioned between the openings 510 on both sides of the insulating cover 500, and the module connector can be exposed to the outside through the connector opening.

[0072] The insulating cover 500 can be positioned on the inner surface of the end plate 400 and can be in close contact with the inner surface of the end plate 400. However, this limitation is not intended.

[0073] As described above, one end portion (second portion 322) of the terminal busbar 320 can be exposed through the opening portion 510, and the exposed end portion (second portion 322) of the terminal busbar 320 can be seated on the seating portion 530. Therefore, the seating portion 530 can be arranged adjacent to the opening portion 510 and can be positioned on the upper outer surface.

[0074] The second portion 322 of the terminal busbar 320 can be seated on the upper surface of the seated portion 530, and therefore the upper surface of the seated portion 530 can form a seated surface. Additionally, as... Figure 4 As shown, the seating portion 530 may include a fixing member 531 for fixing the terminal busbar 320.

[0075] The fixing member 531 can fix the second part 322 of the terminal busbar 320 and may include a fixing hole 531a.

[0076] A retaining pin (not shown) can be inserted into a retaining hole 531a. A retaining pin (not shown) inserted into a connecting hole 322a formed in the second part 322 of the terminal busbar 320 is connected and fixed to the retaining hole 531a, so that the second part 322 of the terminal busbar 320 can be fixed to the insulating cover 500.

[0077] Therefore, the second portion 322 of the terminal busbar 320 sits on the sitting portion 530 of the insulating cover 500, and the second portion 322 sits on and contacts the fixing member 531 arranged in the sitting portion 530.

[0078] A terminal cover portion (not shown) covering one exposed end portion (second portion 322) of the terminal busbar 320 may be disposed on the insulating cover 500.

[0079] like Figures 5 to 7 As shown, in this exemplary embodiment, the battery cell 110 can be provided as a pouch battery cell, and the number of pouch battery cells stacked per unit area can be maximized. However, the battery cell 110 does not necessarily need to be provided as a pouch battery cell, and can instead be provided in a prismatic, cylindrical, or various other forms.

[0080] The battery cell 110, provided in the form of a pouch battery cell, may include an electrode assembly 120 and a battery case 130 for housing the electrode assembly 120.

[0081] The battery compartment 130 of the battery cell 110 is used to house the electrode assembly 120, and can be a pouch-type battery compartment 130. The battery compartment 130 includes a lower compartment 131 and an upper compartment 132 covering the lower compartment 131, and the upper compartment 132 and the lower compartment 131 can be integrally formed. Additionally, as... Figure 6 As shown, the upper box 132 and the lower box 131 can be configured such that the connecting portion of the upper box and the lower box is bent and folded. Figure 6 The illustration shows that the upper portion of the upper box 132 is opened relative to the upper portion of the lower box 131 to reveal the internal state of the pouch-type battery unit 110; however, in the actual finished product, as... Figure 5 As shown, the upper box 132 can completely cover the lower box 131 and can form a sealed portion along the periphery.

[0082] Each of the upper box 132 and the lower box 131 may be composed of a laminated structure comprising an inner cover layer, a metal layer, and an outer cover layer. The inner cover layer is positioned inside the battery box 115 relative to the metal layer and needs to have insulating properties and electrolyte resistance because it is in direct contact with the electrode assembly 120. In addition, for sealing with the outside, good sealing performance is required; that is, the sealed portion formed by thermal bonding between the inner layers needs to exhibit excellent thermal bond strength. The material used for the inner cover layer may be selected from polyolefin-based resins such as polypropylene, polyethylene, poly(propylene-acrylic acid), and polybutene, polyurethane resins, and polyimide resins that exhibit excellent chemical resistance and good sealing performance, and polypropylene (PP) that exhibits excellent mechanical properties, such as tensile strength, stiffness, surface hardness, and impact strength, as well as chemical resistance, is preferred.

[0083] A metal layer is positioned between the inner and outer cover layers and acts as a barrier layer to prevent moisture or various gases from penetrating into the battery from the outside. A preferred material for the metal layer in contact with the inner cover layer is a lightweight aluminum (Al) thin film with excellent formability.

[0084] The outer cover layer is positioned relative to the metal layer on the outside of the battery compartment 130. For the outer cover layer, a heat-resistant polymer with excellent tensile strength, moisture impermeability, and air impermeability can be used to ensure heat resistance and chemical resistance while protecting the electrode components. For example, nylon or polyethylene terephthalate can be used.

[0085] Each of the upper box 132 and the lower box 131 may be formed to have a receiving groove 133, and the electrode assembly may be received in the receiving groove 133 of the upper box 132 and the lower box 131.

[0086] The electrode assembly 120 housed in the battery case 130 can be selected from the group consisting of: a wound electrode assembly having a structure in which spacers are inserted between elongated sheet-shaped positive and negative electrodes and the resulting laminate is then wound; a stacked electrode assembly including a cell having a rectangular stack of positive and negative electrodes with spacers inserted between them; a stacked and folded electrode assembly in which a cell is wound using an elongated spacer film; and a laminated and stacked electrode assembly in which cell cells are stacked with spacers inserted between them and attached to each other.

[0087] In this disclosure, the electrode assembly 120 may include, for example, an electrode stack 125 and a retaining strap 129 for winding the electrode stack 125, such as Figure 7 As shown.

[0088] The electrode stack 125 may include a positive electrode 126, a negative electrode 128, and a separator 127 disposed between the positive electrode 126 and the negative electrode 128, and may be formed by stacking the positive electrode 126, the separator 127, and the negative electrode 128. Additionally, the electrode stack 125 may have a length in the longitudinal direction that is longer than its length in the width direction.

[0089] The positive electrode may include a positive current collector and a first active material layer disposed on the positive current collector, and the first active material layer may be formed by applying an electrode active material to one or both surfaces of the positive current collector.

[0090] The negative electrode may include a negative electrode current collector and a second active material layer disposed on the negative electrode current collector, and the second active material layer may be formed by applying an electrode active material to one or both surfaces of the negative electrode current collector.

[0091] The fixing strap 129 is used to fix the electrode stack 125 in which the positive electrode 126, the separator 127 and the negative electrode 128 are stacked, and the electrode stack 125 is fixed by wrapping around the outside of the electrode stack 125.

[0092] The electrode stack 125 may include a plurality of positive electrodes 126, a plurality of negative electrodes 128 and a plurality of spacers 127.

[0093] Additionally, the electrode assembly 120 may include two electrode tabs 111 and 112 and two electrode leads 121 and 122.

[0094] Electrode contacts 111 and 112 protrude outward from the electrode stack 125. One of the two electrode contacts 111 and 112, electrode contact 111, may be a positive electrode contact connected (extending) to the positive electrode 126, and the other electrode contact 112 may be a negative electrode contact connected (extending) to the negative electrode 128.

[0095] Electrode leads 121 and 122 are connected to electrode contacts 111 and 112, and can be connected to electrode contacts 111 and 112, for example, by soldering. No material can be used for electrode leads 121 and 122 without particular limitation, as long as it is conductive. For example, the material of electrode leads 121 and 122 may include at least one of copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), carbon (C), chromium (Cr), and manganese (Mn). However, the material of electrode leads 121 and 122 is not limited to the above-mentioned materials, and mechanical strength, flexibility, and machinability can be selected in various ways.

[0096] The welding portion can be formed by vertically overlapping certain portions of electrode leads 121 and 122 with certain portions of electrode tabs 111 and 112 and welding the overlapping portions, and the electrode tabs 111 and 112 and the electrode leads 121 and 122 can be connected to each other through the welding portion.

[0097] One of the two electrode leads 121 and 122, electrode lead 121, can be a positive electrode lead connected to the positive terminal, and the other electrode lead 122 can be a negative electrode lead connected to the negative terminal. The positive electrode lead can be made of, for example, aluminum, and the negative electrode lead can be made of, for example, copper or nickel-plated copper. However, such limitation is not intended.

[0098] Lead film 113 can be attached to each of electrode leads 121 and 122, such as Figures 5 to 7 As shown. The lead film 113 attached to the electrode leads 121 and 122 is positioned between the electrode leads 121 and 122 and the battery box 130 to prevent short circuits between the electrode leads 121 and 122 and the battery box 130 and to improve the sealing strength, thereby preventing leakage of electrolytes, etc.

[0099] The lead film 113 can be configured such that a pair of lead films 113 are positioned on two surfaces of each of the electrode leads 121 and 122, and the portions of the lead films that do not contact the electrode leads 121 and 122 are connected to each other by thermal fusion or the like, thereby wrapping the electrode leads 121 and 122, and are formed such that after sealing the battery case 130, a portion of the lead film 113 protrudes outside the battery case 130 to help prevent short circuits.

[0100] The two electrode leads 121 and 122 are shown arranged on both sides of the electrode assembly 120, but depending on the arrangement of the electrode contacts 111 and 112, they can also be arranged on one side of the electrode assembly 120. That is, when the two electrode contacts 111 and 112 are arranged on one side of the electrode assembly 120, the two electrode leads 121 and 122 connected to the electrode contacts 111 and 112 can also be formed in the same direction of the electrode assembly 120.

[0101] Figure 8 and Figure 9 Electrode leads 121 and 122 are shown in an exemplary embodiment of this disclosure. In an exemplary embodiment of this disclosure, electrode leads 121 and 122 may be leads connected by two or more types of materials (metals). Electrode leads 121 and 122 may be made of composite metals.

[0102] As shown, electrode leads 121 and 122 may include first conductor portions 121a and 122a and second conductor portions 121b and 122b connected to the first conductor portions 121a and 122a, and the first conductor portions 121a and 122a and the second conductor portions 121b and 122b may be made of different metals. In this exemplary embodiment, electrode leads 121 and 122 are formed by connecting two or more different materials, which can improve heat dissipation characteristics and mitigate the temperature rise of the battery and electrode leads caused by the current applied to and generated from the battery cell.

[0103] Specifically, the first conductor portions 121a and 122a may be made of a first metal, and the second conductor portions 121b and 122b may be made of a second metal different from the first metal. For example, the first metal may be aluminum (Al), and the second metal may be copper (Cu) or nickel-plated copper. The second metal may be a metal with a higher thermal conductivity than the first metal. The second metal may be a metal with a thermal conductivity at least 1.5 times that of the first metal. In this way, in this exemplary embodiment, the heat generation performance of the entire electrode leads 121 and 122 can be improved by connecting the second conductor portions 121b and 122b with high thermal conductivity to the longitudinal end portions of the first conductor portions 121a and 122a.

[0104] As another example, the first metal can be copper or nickel-plated copper, and the second metal can be aluminum. The first or second metal can be a plating metal or an alloy.

[0105] The first conductor portions 121a and 122a can be connected to the electrode contacts 111 and 112 of the electrode assembly 120, respectively. The first conductor portion 121a of the electrode lead 121 can be connected to the electrode contact 111, which serves as the positive electrode contact, and in this case, the electrode lead 121 can be a positive electrode lead. When the electrode contact 111, which serves as the positive electrode contact, is made of aluminum, a connection with the aluminum first conductor portion 121a using the same metal can be achieved, thereby improving the connection performance.

[0106] The first conductor portion 122a of the electrode lead 122 can be connected to the electrode contact 112, which serves as the negative electrode contact, and in this case, the electrode lead 122 can be the negative electrode lead.

[0107] like Figure 9As shown, grooves 121d and 122d can be formed in the connecting surfaces 121c and 122c of the first conductor portions 121a and 122a that connect with the second conductor portions 121b and 122b. Grooves 121d and 122d can extend along the width direction of the first conductor portions 121a and 122a, and can be formed over the entire width of the first conductor portions 121a and 122a.

[0108] The grooves 121d and 122d can have a predetermined depth from the connecting surfaces 121c and 122c in the inward direction of the first conductor portions 121a and 122a, and the connecting protrusions 121e and 122e of the second conductor portions 121b and 122b can be inserted into the grooves 121d and 122d and connected to the grooves 121d and 122d.

[0109] The first conductor portions 121a and 122a can be housed inside the pouch-type battery box 130.

[0110] The second conductor portions 121b and 122b can be connected to the first conductor portions 121a and 122a, and can be connected to the first conductor portions 121a and 122a in their longitudinal direction.

[0111] The second conductor portions 121b and 122b can be made of a second metal different from the first metal. As an example, the second metal can be copper (Cu).

[0112] like Figure 9 As shown, in this exemplary embodiment, the second conductor portions 121b and 122b may include connecting protrusions 121e and 122e on the connecting surfaces 121c and 122c that are connected to the first conductor portions 121a and 122a.

[0113] The connecting protrusions 121e and 122e can extend along the width direction of the second conductor portions 121b and 122b, and can be formed over the entire width of the second conductor portions 121b and 122b.

[0114] The connecting protrusions 121e and 122e can protrude a predetermined length from the connecting surfaces 121c and 122c along the direction of the first conductor portions 121a and 122a, and the connecting protrusions 121e and 122e can be inserted into the grooves 121d and 122d of the first conductor portions 121a and 122a and connected to the grooves 121d and 122d.

[0115] In this way, the connecting protrusions 121e and 122e of the second conductor portions 121b and 122b are connected to the grooves 121d and 122d of the first conductor portions 121a and 122a at the connecting surfaces 121c and 122c of the first conductor portions 121a and 122a and the second conductor portions 121b and 122b, thereby improving the connection strength between the first conductor portions 121a and 122a and the second conductor portions 121b and 122b.

[0116] The second conductor portions 121b and 122b may be exposed to the outside of the battery case 130, and at least a portion of the second conductor portions 121b and 122b may be exposed to the outside of the battery case 130. The portions of the second conductor portions 121b and 122b exposed to the outside of the battery case 130 may be connected to busbars 310 and 320. As described above, the electrode leads 121 and 122 of the battery cell 110 may be connected to busbars 310 and 320 arranged on the busbar frame 300, and the second conductor portions 121b and 122b of the electrode leads 121 and 122 exposed from the battery case 130 may be connected to busbars 310 and 320.

[0117] The lead film 113 can be disposed on the electrode leads 121, 122, and as follows: Figure 8 As shown, the lead film 113 can cover the connection boundaries (connection surfaces 121c, 122c) of the first conductor portions 121a, 122a and the second conductor portions 121b, 122b. That is, the upper portion of the connection surfaces 121c, 122c can be covered by the lead film 113.

[0118] In this exemplary embodiment, electrode leads formed by connecting materials with high thermal conductivity are used, which improves heat dissipation characteristics and thus alleviates the temperature rise of the battery and electrode leads caused by the current applied to and generated from the battery cell.

[0119] This improves the battery cell's output, fast charging, and safety.

[0120] Note that, Figure 10 Electrode leads 121, 122 according to a second exemplary embodiment of the present disclosure are shown, which differ from the previous exemplary embodiment in that the first conductor portions 121a, 122a have connecting protrusions 121g, 122g and the second conductor portions 121b, 122b have grooves 121f, 122f.

[0121] In other words, Figure 10In this process, grooves 121f and 122f can be formed in the connecting surfaces 121c and 122c of the second conductor portions 121b and 122b that connect with the first conductor portions 121a and 122a. Grooves 121f and 122f can extend along the width direction of the second conductor portions 121b and 122b, and can be formed over the entire width of the second conductor portions 121b and 122b.

[0122] The grooves 121f and 122f may have a predetermined depth in the inward direction from the connecting surfaces 121c and 122c along the second conductor portions 121b and 122b, and the connecting protrusions 121g and 122g of the first conductor portions 121a and 122a may be inserted into the grooves 121f and 122f and connected to the grooves 121f and 122f.

[0123] The first conductor portions 121a and 122a may include connecting protrusions 121g and 122g on the connecting surfaces 121c and 122c that are connected to the second conductor portions 121b and 122b.

[0124] The connecting protrusions 121g and 122g can extend along the width direction of the first conductor portions 121a and 122a, and can be formed over the entire width of the first conductor portions 121a and 122a.

[0125] The connecting protrusions 121g and 122g can protrude a predetermined length from the connecting surfaces 121c and 122c along the direction of the second conductor portions 121b and 122b, and the connecting protrusions 121g and 122g can be inserted into the grooves 121f and 122f of the second conductor portions 121b and 122b and connected to the grooves 121f and 122f.

[0126] In this way, the connecting protrusions 121g and 122g of the first conductor portions 121a and 122a are connected to the grooves 121f and 122f of the second conductor portions 121b and 122b at the connecting surfaces 121c and 122c of the first conductor portions 121a and 122a and the second conductor portions 121b and 122b, thereby improving the connection strength of the first conductor portions 121a and 122a and the second conductor portions 121b and 122b.

[0127] Note that, Figure 11 Electrode leads 121, 122 according to a third exemplary embodiment of the present disclosure are shown, which illustrates an example different from the previous exemplary embodiments in which the first conductor portions 121a, 122a have a wavy connecting surface 121c and the second conductor portions 121b, 122b have a wavy connecting surface 122c.

[0128] In other words, Figure 11 In the first conductor portions 121a and 122a, the connecting surface 121c that connects to the second conductor portions 121b and 122b can be formed with a wave shape. The wave shape can extend along the width direction of the first conductor portions 121a and 122a and can be formed over the entire width of the first conductor portions 121a and 122a.

[0129] The connecting surface 122c of the second conductor portions 121b and 122b can be formed as the connecting surface 121c corresponding to the first conductor portions 121a and 122a. That is, the connecting surface 122c of the second conductor portions 121b and 122b connected to the first conductor portions 121a and 122a can be formed with a wave shape. This wave shape can extend along the width direction of the second conductor portions 121b and 122b, and can be formed over the entire width of the second conductor portions 121b and 122b.

[0130] In this way, since the connecting surfaces 121c and 122c of the first conductor portions 121a and 122a and the second conductor portions 121b and 122b are each formed with a wavy shape, the area of ​​the connecting surfaces 121c and 122c can be increased, and the connection strength can be increased. Furthermore, the increased connecting surface 122c of the second conductor portions 121b and 122b, which have high thermal conductivity, further improves heat dissipation performance. Additionally, since the stress of external forces is distributed at the wavy connecting surfaces, the connection strength can be further improved.

[0131] Note that, Figure 12 Electrode leads 121, 122 according to a fourth exemplary embodiment of the present disclosure are shown, illustrating an example in which the first conductor portions 121a, 122a have a serrated connecting surface 121c and the second conductor portions 121b, 122b have a serrated connecting surface 122c.

[0132] In other words, Figure 12 In the first conductor portions 121a and 122a, the connecting surface 121c that connects to the second conductor portions 121b and 122b can be formed with a serrated shape. The serrated shape can extend along the width direction of the first conductor portions 121a and 122a and can be formed over the entire width of the first conductor portions 121a and 122a.

[0133] The connecting surface 122c of the second conductor portions 121b and 122b can be formed as the connecting surface 121c corresponding to the first conductor portions 121a and 122a. That is, the connecting surface 122c of the second conductor portions 121b and 122b connected to the first conductor portions 121a and 122a can be formed with a serrated shape. This serrated shape can extend along the width direction of the second conductor portions 121b and 122b, and can be formed over the entire width of the second conductor portions 121b and 122b.

[0134] In this way, since the connecting surfaces 121c and 122c of the first conductor portions 121a and 122a and the second conductor portions 121b and 122b are each formed with a serrated shape to engage with each other, the area of ​​the connecting surfaces 121c and 122c can be increased, and the connection strength can be increased. In addition, the increased connecting surface 122c of the second conductor portions 121b and 122b, which has high thermal conductivity, further improves the heat dissipation performance.

[0135] As described above, one or more battery modules 1000 according to this disclosure can form a battery pack 2000. For example... Figure 13 As shown, the battery pack 2000 according to an exemplary embodiment of the present disclosure may house one or more battery modules 1000 in the pack box 2100, and may include various control and protection systems, such as a battery management system (BMS) and a cooling system.

[0136] The assembly box 2100 may include a lower housing 2110 and an upper housing (not shown) connected to the upper side of the lower housing 2110, and multiple battery modules 1000 may be stored in the internal space of the lower housing 2110 and the upper housing.

[0137] Note that in the exemplary embodiments of this disclosure, an example is shown in which a plurality of battery modules 1000 are housed inside a battery pack 2000; however, a plurality of battery cells 110 may be arranged directly inside the battery pack 2000.

[0138] The battery module 1000 and battery pack 2000 constructed in this manner according to the present disclosure can be applied to a variety of devices. Specifically, they can be applied to vehicles such as electric bicycles, electric vehicles and hybrid vehicles, or energy storage systems (ESS), but are not limited thereto, and can be applied to a variety of other devices that use secondary batteries.

[0139] Figure 14 An electric vehicle V equipped with a battery pack 2000 is shown. In the electric vehicle V, the wheels are driven by motors that receive power from the battery pack 2000, thus enabling the electric vehicle to move.

[0140] Although this disclosure has been described with reference to the preferred exemplary embodiments described above, this disclosure is not limited to the exemplary embodiments described above, and various changes and modifications can be made by those skilled in the art to which this disclosure pertains without departing from the spirit of this disclosure. Industrial applicability

[0141] This disclosure can provide electrode leads, electrode assemblies, electrode units including the electrode assemblies, and battery modules including the electrode assemblies that can improve heat dissipation characteristics.

Claims

1. An electrode assembly, the electrode assembly comprising: positive electrode; negative electrode; A separator is disposed between the positive electrode and the negative electrode; as well as Electrode leads, wherein the electrode leads are connected to the positive electrode or the negative electrode, wherein... The electrode leads include: The first conductor portion, and The second conductor portion is connected to the first conductor portion in the longitudinal direction.

2. The electrode assembly according to claim 1, wherein, The first conductor portion is made of a first metal, and The second conductor portion is made of a second metal that is different from the first metal.

3. The electrode assembly according to claim 2, wherein, The electrode lead is connected to the positive electrode.

4. The electrode assembly according to claim 3, wherein, The first metal is aluminum.

5. The electrode assembly according to claim 3, wherein, The first conductor portion of the electrode lead is connected to the positive electrode contact of the positive electrode.

6. The electrode assembly according to claim 4, wherein, The second metal is copper or nickel-plated copper.

7. The electrode assembly according to claim 2, wherein, The first conductor portion includes a groove located in the connecting surface that connects to the second conductor portion, and The second conductor portion includes a connecting protrusion located on a connecting surface connected to the first conductor portion, the connecting protrusion being connected to the groove.

8. The electrode assembly according to claim 2, wherein, The first conductor portion includes a connecting protrusion located on a connecting surface that connects to the second conductor portion, and The second conductor portion includes a groove located in a connecting surface connected to the first conductor portion, and the connecting protrusion is connected to the groove.

9. The electrode assembly according to claim 1, wherein, The first conductor portion and the second conductor portion each have a wavy connecting surface extending in the width direction.

10. The electrode assembly according to claim 1, wherein, The first conductor portion and the second conductor portion each have a serrated connecting surface extending in the width direction.

11. A battery cell, the battery cell comprising: Electrode assembly; as well as A battery case, configured to house the electrode assembly, wherein... The electrode assembly includes: positive electrode; negative electrode; A separator, the separator being disposed between the positive electrode and the negative electrode; and Electrode leads, the electrode leads being connected to the positive electrode or the negative electrode, and The electrode lead includes: a first conductor portion; and a second conductor portion, the second conductor portion being connected to the first conductor portion in the longitudinal direction.

12. The battery cell according to claim 11, wherein, The first conductor portion is made of a first metal, and the second conductor portion is made of a second metal different from the first metal.

13. The battery cell according to claim 12, wherein, The first conductor portion of the electrode lead is connected to the positive electrode contact of the positive electrode.

14. The battery cell according to claim 13, wherein, The first conductor portion of the electrode lead is disposed inside the battery box.

15. The battery cell according to claim 13, wherein, The first metal is aluminum.

16. The battery cell according to claim 15, wherein, The second metal is copper or nickel-plated copper.

17. The battery cell according to claim 12, wherein, The first conductor portion includes a groove located in the connecting surface that connects to the second conductor portion, and The second conductor portion includes a connecting protrusion located on a connecting surface connected to the first conductor portion, the connecting protrusion being connected to the groove.

18. The battery cell according to claim 12, wherein, The first conductor portion includes a connecting protrusion located on a connecting surface that connects to the second conductor portion, and The second conductor portion includes a groove located in a connecting surface connected to the first conductor portion, and the connecting protrusion is connected to the groove.

19. A battery module comprising a plurality of battery cells according to claim 11.

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