Electrode assembly, battery cell comprising same, and electrode lead welding method

Abstract

The invention relates to an electrode assembly, a battery cell comprising the electrode assembly and an electrode lead welding method. An electrode assembly according to one embodiment of the present invention may include a plurality of electrodes having electrode tabs and electrode leads coupled to the electrode tabs. The plurality of electrode tabs may include a first electrode tab and a second electrode tab coupled to one surface of the electrode lead and different in appearance from the first electrode tab.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2023-0149462, filed on November 1, 2023, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to electrode assemblies, battery cells including the electrode assemblies, and electrode lead welding methods. Background Technology

[0004] Recently, the consumption of fossil fuels has driven up energy prices and significantly impacted growing concerns about environmental pollution, making the demand for environmentally friendly alternative energy sources a crucial factor for future living. Against this backdrop, research is underway into various energy generation technologies, including solar, wind, and tidal power, with a focus on energy storage systems such as batteries to more efficiently utilize the generated electricity.

[0005] Furthermore, with the increasing development and demand for technologies that utilize batteries in electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly increasing. Therefore, much research is being conducted on batteries that can meet various needs.

[0006] Batteries are gaining attention as an energy source in a variety of products, including mobile devices and electric vehicles. In particular, rechargeable batteries are considered a promising energy source that can replace existing products that use fossil fuels and does not produce byproducts from energy use, thus attracting attention as an environmentally friendly energy source.

[0007] At the same time, secondary batteries are also gaining attention as an energy source for electric vehicles (EVs), hybrid vehicles (HEVs), and plug-in hybrid vehicles (PHEVs), which are seen as a solution to reduce air pollution from existing vehicles that use fossil fuels, such as gasoline and diesel vehicles. In other words, secondary batteries are used in the form of battery packs comprising multiple battery modules.

[0008] A secondary battery includes a positive electrode and a negative electrode, which are stacked with a separator between them to form an electrode assembly. Electrode terminals are formed on each of the positive and negative electrodes, and since they are formed on multiple positive and multiple negative electrodes, multiple electrode terminals are also formed. These multiple electrode terminals are electrically connected to electrode leads. Typically, electrode terminals are made of metal. Recently, electrode terminals have begun to be made of materials other than metals. A typical example is a metallized film, where metal is deposited on a non-metallic material, particularly a polymer layer.

[0009] Typically, electrode connectors are attached to each other by pre-welding, and then leads are driven to one side and welded. However, the problem with this method is that welding does not perform well when grafted onto the metallization film, or even if welding is achieved, the fusion strength is insufficient, leading to partial detachment. This also results in numerous defects during the assembly process of secondary batteries. Summary of the Invention

[0010] Technical issues

[0011] This disclosure is designed to solve problems in related technologies, and therefore aims to provide an electrode assembly, a battery cell including the electrode assembly, and an electrode lead welding method, wherein some electrode joints are made to be different in appearance from other electrode joints, so that the position of the electrode leads can be easily determined when welding is performed by setting electrode leads between the electrode joints.

[0012] Technical solution

[0013] An electrode assembly according to an embodiment of the present disclosure may include a plurality of electrodes having electrode connectors; and electrode leads coupled to the electrode connectors, wherein the plurality of electrode connectors may include a first electrode connector and a second electrode connector, the second electrode connector being coupled to a surface of the electrode lead and being different in appearance from the first electrode connector.

[0014] The second electrode connector can be formed to have a different color than the first electrode connector.

[0015] The second electrode connector may include a material with less rigidity than the first electrode connector.

[0016] The second electrode connector can be connected to at least one of the two surfaces of the electrode lead.

[0017] Each of the first electrode connector and the second electrode connector may include a pair of metal layers disposed on the outermost side, and a non-metallic layer disposed between the pair of metal layers.

[0018] The metal layers can be deposited on both surfaces of the non-metal layer.

[0019] The non-metallic layer may include a polymer, and the metallic layer may include aluminum.

[0020] Electrode leads can be connected to electrode connectors at the center of the electrode in the thickness direction.

[0021] The same number of electrode connectors can be set in both the upper and lower surface directions of the electrode leads.

[0022] The electrode leads and the second electrode connector can be connected by welding.

[0023] The first electrode connector may include a pair of metal layers disposed on the outermost side and a non-metallic layer disposed between the pair of metal layers, wherein the second electrode connector may be made of metal.

[0024] A battery cell according to an embodiment of the present disclosure may include an electrode assembly and a battery casing housing the electrode assembly.

[0025] The electrode lead welding method according to the embodiments of this disclosure can weld electrode connectors and electrode leads.

[0026] The electrode lead welding method may include: the step of setting the electrode lead at the location of the electrode connector; and the step of welding the electrode connector and the electrode lead, wherein the electrode connector may include a first electrode connector and a second electrode connector, the second electrode connector being connected to a surface of the electrode lead and being different in appearance from the first electrode connector, wherein, in the step of setting the electrode lead, the electrode lead may be set at the location of the second electrode connector.

[0027] Beneficial effects

[0028] According to the preferred embodiment of this disclosure, the following effects are achieved: the color of the electrode connector adjacent to the portion where the electrode leads are disposed can be manufactured differently, or a soft material can be used, thereby making it easy to determine the point where the electrode leads are disposed.

[0029] In addition, the electrode joint adjacent to the electrode lead is made of a softer material than other electrode joints, thus achieving the desired fusion strength when soldered to the electrode lead. Attached Figure Description

[0030] The accompanying drawings illustrate exemplary embodiments of the present disclosure and are used, together with the following detailed description, to provide a further understanding of the technical aspects of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the drawings.

[0031] Figure 1 This is a schematic diagram of a battery cell according to an embodiment of the present disclosure.

[0032] Figure 2 yes Figure 1 A magnified view of part A.

[0033] Figure 3 yes Figure 1 The diagram shows the electrode and electrode connector.

[0034] Figure 4 This is an enlarged view of the welded portion between the electrode connector and the electrode lead of an electrode assembly according to another embodiment of the present disclosure.

[0035] Figure 5This is a cross-sectional view showing the cross-section of an electrode connector according to an embodiment of the present disclosure.

[0036] Figure 6 This is a flowchart of an electrode lead welding method according to another embodiment of the present disclosure. Detailed Implementation

[0037] In the following description, exemplary embodiments of the present disclosure will be described in sufficient detail with reference to the accompanying drawings to enable those skilled in the art to readily perform the present disclosure. However, the present disclosure may be implemented in many different forms and is not limited to or construed as described below.

[0038] In order to clearly describe this disclosure, detailed descriptions of relevant known techniques or irrelevant descriptions that may unnecessarily obscure the main points of this disclosure have been omitted, and throughout this disclosure, the same or similar reference numerals are attached to the same or similar elements when reference numerals are attached to the elements in each figure.

[0039] Furthermore, it should be understood that the terms or words used in this disclosure and the appended claims should not be construed as limited to their general and dictionary meanings, but rather as interpreted based on the principle that the inventors are permitted to properly define terms for the best interpretation, and based on the meanings and concepts corresponding to the technical aspects of this disclosure.

[0040] Electrode components and battery cells

[0041] In the following text, reference will be made to Figures 1 to 5 The present disclosure describes in detail the electrode assembly 10 and the battery cell 1 including the electrode assembly according to embodiments thereof.

[0042] Figure 1 This is a schematic diagram of a battery cell according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A magnified view of part A. Figure 3 yes Figure 1 The diagram shows a plan view of the electrodes and electrode connectors. Figure 4 This is an enlarged view of the welded portion between the electrode leads and the electrode connector of an electrode assembly according to another embodiment of the present disclosure, and Figure 5 This is a cross-sectional view showing the cross-section of an electrode connector according to an embodiment of the present disclosure.

[0043] Reference Figure 1 The battery cell 1 according to embodiments of the present disclosure may include an electrode assembly 10 and a battery casing 20. The electrode assembly 10 may be housed within the battery casing 20. An electrolyte may be contained within the battery casing 20. The electrode assembly 10 may be impregnated with the electrolyte. The electrolyte may permeate the electrode assembly 10, which allows ions to move between the electrodes. The battery casing 20 may be formed of a pouch-like material.

[0044] The electrode assembly 10 according to embodiments of the present disclosure may include a plurality of electrodes 11 and electrode leads 13. The electrode assembly 10 may be formed by stacking the electrodes 11 and the diaphragm on top of each other.

[0045] Multiple electrodes 11 may each be provided with an electrode connector 12. Electrode 11 may be a positive electrode or a negative electrode. A positive electrode may include a region coated with an active material layer and an uncoated positive electrode region without an active material layer. A negative electrode may include a region coated with an active material layer and an uncoated negative electrode region without an active material layer.

[0046] There can be multiple electrode connectors 12, as they are connected to each of the multiple electrodes 11. Electrode connector 12 can be a positive connector or a negative connector. A positive connector is an electrode connector 12 connected to the positive terminal, and a negative connector is an electrode connector 12 connected to the negative terminal. Both the positive and negative connectors can be connected to electrode leads 13.

[0047] The electrode connector 12 may include a first electrode connector 121 and a second electrode connector 122.

[0048] The first electrode connector 121 can be a positive or negative connector. Multiple first electrode connectors 121 can be formed. Multiple first electrode connectors 121 can be welded to each other.

[0049] The second electrode connector 122 can be connected to one surface of the electrode lead 13. The second electrode connector 122 can also be connected to at least one of the two surfaces of the electrode lead 13. That is, the second electrode connector 122 can be connected to either the lower or upper surface of the electrode lead 13. (See reference) Figure 2 The electrode assembly according to embodiments of this disclosure may include a single second electrode connector 122. Additionally, refer to... Figure 4 The electrode assembly according to embodiments of the present disclosure may include a pair of second electrode connectors 122.

[0050] The second electrode connector 122 may differ in appearance from the first electrode connector 121.

[0051] In one example, the second electrode connector 122 may be formed in a different color than the first electrode connector 121. Because the second electrode connector 122 is formed in a different color than the first electrode connector 121, the location where the electrode leads 13 are positioned and soldered can be easily determined. The color of the second electrode connector 122 can be distinguished from the color of the first electrode connector 121.

[0052] Electrode lead 13 can be soldered to second electrode connector 122. After the electrode lead 13 is positioned between second electrode connector 122 and first electrode connector 121, electrode lead 13 and electrode connector 12 can be soldered.

[0053] The first electrode connector 121 and the second electrode connector 122 may each include a pair of metal layers 123 and non-metal layers 124. The first electrode connector 121 and the second electrode connector 122 may be metallized films, wherein the metal layers are deposited on the non-metal layers. The metallized films may be formed to be thinner than electrode connectors made of metal.

[0054] Depending on the manufacturing process, metallized films can be divided into deposited films and laminated films. Deposited films are manufactured by deposition methods, while laminated films are manufactured by applying pressure, and generally, laminated films have less rigidity than deposited films. There are also differences in appearance. In this disclosure, the second electrode connector 122 is formed of a laminated film, and the first electrode connector 121 is formed of a deposited film. This makes it easy to identify the portion of the electrode lead 13 to be welded, and because the second electrode connector 122 welded to the electrode lead 13 is formed of a laminated film with weaker rigidity, the desired fusion strength can be achieved.

[0055] The metal layers 123 are arranged in pairs and may be located on the outermost side. The metal layers 123 may include aluminum. The metal layers 123 may be provided so that the electrode connectors 12 can be electrically connected to each other.

[0056] A non-metallic layer 124 may be disposed between a pair of metallic layers 123. The metallic layers 123 may be deposited on both surfaces of the non-metallic layer 124, respectively. Because the metallic layers 123 are deposited on the non-metallic layer 124, the electrode connector 12 can be formed thinner than if it were formed solely of metal. The non-metallic layer 124 may comprise a polymer.

[0057] As another example, the second electrode connector 122 may comprise a material less rigid than the first electrode connector 121. If the second electrode connector 122 is made of a soft material, welding defects between the second electrode connector 122 and the electrode lead 13 can be reduced when welding the electrode lead 13 and the electrode connector 12. Because it is a soft material, better fusion can be achieved during welding.

[0058] The second electrode connector 122 may differ in appearance from the first electrode connector 121, and in this case, the first electrode connector 121 may include a pair of metal layers 123 and non-metal layers 124 as described above. The second electrode connector 122 may be a laminated film.

[0059] Electrode lead 13 can be connected to electrode connector 12 at the center of electrode 11 in the thickness direction. Electrode lead 13 can be electrically connected to electrode connector 12. Lead film can be connected to electrode lead 13. Lead film can be disposed between electrode lead 13 and battery housing 20.

[0060] Electrode lead 13 can be arranged adjacent to the second electrode connector 122. For example... Figure 2 As shown, electrode lead 13 can be positioned above the second electrode connector 122 and soldered. That is, when determining the position for soldering electrode lead 13, it can be easily determined by examining the second electrode connector 122. However, this disclosure is not limited thereto, and as... Figure 4 As shown, the second electrode connector 122 can be positioned above the electrode lead 13. In this case, the electrode lead 13 can be positioned below the second electrode connector 122 and soldered.

[0061] An equal number of electrode connectors 12 should be positioned above and below the electrode leads 13 for soldering, and unless otherwise specified, the number of electrode connectors 12 will need to be counted. However, since the second electrode connector 122 is formed differently in appearance from the first electrode connector 121 as described above, the position of the second electrode connector 122 can be quickly determined, and the position where the electrode leads 13 should be positioned is easily known. This has the effect of omitting the process of counting the number of electrode connectors 12.

[0062] Based on the electrode lead 13, the same number of electrode connectors 12 can be provided in both the upper and lower surface directions of the electrode lead 13. The electrode lead 13 and the second electrode connector 122 can be connected by welding. The electrode lead 13 can also be connected to the first electrode connector 121 by welding.

[0063] Electrode lead soldering method

[0064] In the following text, reference will be made to Figure 2 , Figure 4 and Figure 6 A detailed description of an electrode lead welding method according to embodiments of the present disclosure is provided.

[0065] Figure 2 It is shown Figure 1 A schematic diagram of the electrode assembly shown. Figure 4 This is a schematic diagram illustrating an electrode assembly according to another embodiment of the present disclosure. Figure 6 This is a flowchart of an electrode lead welding method according to another embodiment of the present disclosure.

[0066] In the following description, the electrode lead welding method using the above-described electrode assembly 10 and battery cell 1 will be described as another embodiment of this disclosure.

[0067] Reference Figure 6 The electrode connector 12 and the electrode lead 13 can be welded using an electrode lead welding method according to an embodiment of the present disclosure. The electrode lead welding method according to an embodiment of the present disclosure may include a step S1 of setting the electrode lead and a step S2 of welding the electrode connector 12 and the electrode lead 13.

[0068] In step S1 of setting the electrode lead, the electrode lead 13 can be positioned at the location of the second electrode connector 122. More specifically, the electrode lead 13 can be positioned to contact the second electrode connector 122. Since the electrode lead 13 should be positioned at the center of the electrode 11 in the thickness direction and welded thereon, the electrode lead 13 should be positioned at the location of the second electrode connector 122. As described above, the second electrode connector 122 is visually different from the first electrode connector 121, which has the effect of easily determining the position of the electrode lead 13.

[0069] In step S2, the electrode lead 13 and the electrode connector 12 can be welded together. At this time, multiple electrode connectors 12 can be welded at once.

[0070] In step S2 of welding the electrode leads, the number of electrode joints 12 located below the electrode lead 13 may be greater than the number of electrode joints 12 located above the electrode lead 13. If the number of electrode joints 12 located above the electrode lead 13 is greater than the number of electrode joints 12 located below the electrode lead 13, the target fusion strength may not be achieved, or welding may not be possible, when welding the electrode lead 13 and the second electrode joint 122.

[0071] In conventional electrode lead soldering methods, the electrode leads are soldered after a pre-soldering step, in which the electrode connectors are soldered separately. However, in the method of this disclosure, the electrode leads 13 and the electrode connectors 12 can be soldered together in one step without a pre-soldering step.

[0072] However, if the electrode lead 13 is driven and positioned on one side of the electrode connector 12 as in the past and then welded, there is a problem that welding cannot be performed. In this disclosure, the electrode lead 13 is positioned between the electrode connectors 12 and welded, and the electrode lead 13 is positioned at the center of the electrode 11 in the thickness direction and welded to facilitate welding. Therefore, there is an effect that welding can be performed by properly positioning the electrode lead 13 via providing a second electrode connector 122.

[0073] The present disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, but the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure pertains may implement the present disclosure in various forms within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

[0074] [List of reference numerals]

[0075] 1: Battery cells

[0076] 10: Electrode assembly

[0077] 11: Electrode

[0078] 12: Electrode connector

[0079] 121: First electrode connector

[0080] 122: Second electrode connector

[0081] 123: Metal layer

[0082] 124: Non-metallic layer

[0083] 13: Electrode leads

[0084] 20: Battery casing

[0085] S1: Setup Steps

[0086] S2: Welding steps

Claims

1. An electrode assembly, the electrode assembly comprising: Multiple electrodes, wherein the multiple electrodes have electrode connectors; as well as Electrode leads, which are connected to the electrode connector. The plurality of electrode connectors include: First electrode connector; and The second electrode connector is attached to one surface of the electrode lead and is different in appearance from the first electrode connector.

2. The electrode assembly according to claim 1, in, The second electrode connector is formed in a different color than the first electrode connector.

3. The electrode assembly according to claim 1, in, The second electrode connector comprises a material with lower rigidity than the first electrode connector.

4. The electrode assembly according to claim 1, in, The second electrode connector is attached to at least one of the two surfaces of the electrode lead.

5. The electrode assembly according to claim 1, in, Each of the first electrode connector and the second electrode connector includes: A pair of metal layers set on the outermost side; and A non-metallic layer is disposed between the pair of metallic layers.

6. The electrode assembly according to claim 5, in, The pair of metal layers are deposited on the two surfaces of the non-metal layer.

7. The electrode assembly according to claim 5, in, The non-metallic layer comprises a polymer, and The metal layer comprises aluminum.

8. The electrode assembly according to claim 1, in, The electrode lead is connected to the electrode connector at the center of the electrode in the thickness direction.

9. The electrode assembly according to claim 1, in, Based on the electrode lead, the same number of electrode connectors are provided in the upper surface direction and the lower surface direction of the electrode lead.

10. The electrode assembly according to claim 1, in, The electrode lead and the second electrode connector are connected by welding.

11. The electrode assembly according to claim 1, in, The first electrode connector includes: A pair of metal layers set on the outermost side; and A non-metallic layer disposed between the pair of metallic layers The second electrode connector is made of metal.

12. A battery cell, the battery cell comprising: The electrode assembly according to claim 1; as well as A battery housing in which the electrode assembly is housed.

13. A method for welding electrode leads to electrode connectors and electrode leads, the method comprising the following steps: The step of setting the electrode lead at the location of the electrode connector; as well as The step of welding the electrode connector and the electrode lead. The electrode connector includes: First electrode connector; and The second electrode connector is attached to one surface of the electrode lead and is different in appearance from the first electrode connector. In the step of setting the electrode leads, The electrode lead is located at the position of the second electrode connector.

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