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

Abstract

The electrode assembly according to the present invention is characterized by comprising: a plurality of electrodes having electrode tabs; and an electrode lead connected to the electrode tabs, in which the plurality of electrode tabs include a first type of electrode tab and a second type of electrode tab coupled to one surface of the electrode lead and extending further than the first type of electrode tab.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2023-0149501, filed in Korea on November 1, 2023, and Korean Patent Application No. 10-2024-0148952, filed in Korea on October 28, 2024, the disclosures of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an electrode assembly, a battery cell including the electrode assembly, and a method for welding electrode leads. Background Technology

[0004] Recently, the depletion of fossil fuels has forced up energy prices and has also had a significant impact on the growing environmental pollution problem, making the demand for environmentally friendly alternative energy sources a crucial factor for future living. Against this backdrop, research is underway on various energy generation technologies, including solar, wind, and tidal power, and attention is being turned to energy storage systems such as batteries to utilize the generated electricity more effectively.

[0005] Furthermore, with the development of technology and the increasing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as an energy source is also rapidly increasing. Therefore, many studies are being conducted on batteries that can meet various needs.

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

[0007] Meanwhile, secondary batteries have also attracted attention as an energy source for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), which are hailed as a solution to reduce air pollution from existing vehicles that use fossil fuels, such as gasoline and diesel cars. 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 together via a separator to form an electrode assembly. Electrode connectors are formed on each of the positive and negative electrodes, and since they are formed on multiple positive and multiple negative electrodes, multiple electrode connectors are also formed. These multiple electrode connectors are electrically connected to electrode leads. Traditionally, electrode connectors are made of metal. Recently, electrode connectors have begun to be made of materials other than metals. A typical example is extended versions where metal is deposited on a non-metallic material, particularly on a polymer layer.

[0009] When electrode joints, which consist of a metal layer deposited on a non-metal layer, extend further, welding the electrode leads and electrode joints becomes difficult. Traditionally, the method involves first welding the electrode joints together and then adding the electrode leads for welding. However, when this method is applied to longer extensions, the welding results are often poor, or even if welding is performed, the target fusion strength cannot be achieved, or partial peeling occurs. Summary of the Invention

[0010] Technical issues

[0011] This disclosure aims to solve the problems of related technologies. Therefore, this disclosure aims to provide an electrode assembly, a battery cell including the electrode assembly, and a method for welding electrode leads. The electrode assembly can easily determine the portion of the electrode leads to be welded to the electrode joint by including an electrode joint formed to extend longer than other electrode joints, so that the position of the electrode leads can be easily determined when welding with electrode leads disposed between the electrode joints.

[0012] Technical solution

[0013] An electrode assembly according to one aspect of this disclosure may include: a plurality of electrodes having electrode connectors; and electrode leads coupled to the electrode connectors, wherein the plurality of electrode connectors include: a first type electrode connector; and a second type electrode connector coupled to a surface of the electrode lead and formed to extend longer than the first type electrode connector.

[0014] The second type of electrode connector can be attached to at least one of the two surfaces of the electrode lead.

[0015] Each of the first type of electrode connector and the second type of electrode connector may include: a pair of metal layers disposed on the outermost side; and a non-metal layer disposed between the pair of metal layers.

[0016] The pair of metal layers are deposited on the two surfaces of the non-metal layer.

[0017] The non-metallic layer may include a polymer, and the metallic layer may include aluminum.

[0018] The electrode lead can be connected to the electrode connector at the center of the electrode along the thickness direction.

[0019] The second type of electrode connector can be configured as a pair of second type electrode connectors, and the pair of second type electrode connectors can be respectively connected to one side and the other side of the electrode lead.

[0020] The pair of second-type electrode connectors can be respectively connected to two opposite side surfaces of the electrode leads.

[0021] Based on the electrode lead, the same number of electrode connectors can be provided in the upper surface direction and the lower surface direction of the electrode lead.

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

[0023] The first type of electrode connector can be configured as a plurality of first type electrode connectors, and the plurality of first type electrode connectors can all have the same length.

[0024] The plurality of electrode connectors can be stacked in one direction.

[0025] According to another aspect of this disclosure, a battery cell may include: an electrode assembly; and a battery housing, wherein the electrode assembly is housed within the battery housing, wherein the electrode assembly may include: a plurality of electrodes having electrode connectors; and electrode leads connected to the electrode connectors, wherein the plurality of electrode connectors include: a first type electrode connector; and a second type electrode connector connected to a surface of the electrode lead and formed to extend longer than the first type electrode connector.

[0026] According to another aspect of this disclosure, an electrode lead welding method can weld an electrode connector and an electrode lead. The electrode lead welding method may include the following steps: positioning the electrode lead at the location of the electrode connector; and welding the electrode connector and the electrode lead, wherein the electrode connector includes: a first type electrode connector; and a second type electrode connector, the second type electrode connector being coupled to a surface of the electrode lead and formed to extend longer than the first type electrode connector, wherein, in the step of positioning the electrode lead, the electrode lead is positioned at the location of the second type electrode connector.

[0027] Beneficial effects

[0028] The electrode assembly, battery cell including the electrode assembly, and electrode lead welding method according to this disclosure include forming an electrode joint that extends longer than other electrode joints, thereby having the effect of easily determining the electrode lead arrangement and welding portion. Attached Figure Description

[0029] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the following detailed description, are intended 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.

[0030] Figure 1 This is a schematic diagram of a battery cell according to an embodiment of the present disclosure.

[0031] Figure 2 yes Figure 1 An enlarged view of part A in the image.

[0032] Figure 3 yes Figure 1 The diagram shows a plan view of the electrodes and electrode connectors.

[0033] Figure 4 This is a schematic diagram illustrating an electrode assembly according to another embodiment of the present disclosure.

[0034] Figure 5 This is a cross-sectional view showing the cross-section of an electrode connector according to an embodiment of the present disclosure.

[0035] Figure 6 This is a flowchart of an electrode lead welding method according to another embodiment of the present disclosure. Detailed Implementation

[0036] In the following, exemplary embodiments of the present disclosure will be described in full detail with reference to the accompanying drawings to enable those skilled in the art to readily perform the disclosure. However, the present disclosure may be embodied in many different forms and is not limited to or construed as described below.

[0037] In order to clearly describe this disclosure, irrelevant descriptions or detailed descriptions of relevant known technologies that may unnecessarily obscure the essential 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.

[0038] 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 are interpreted based on the meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of the principle that inventors are allowed to appropriately define terms to obtain the best interpretation.

[0039] Electrode components and battery cells

[0040] 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.

[0041] Figure 1 This is a schematic diagram of a battery cell according to an embodiment of the present disclosure. Figure 2 yes Figure 1 An enlarged view of part A in the image. Figure 3 yes Figure 1 The diagram shows a plan view of the electrodes and electrode connectors. Figure 4 This is a schematic diagram illustrating 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.

[0042] Reference Figure 1 According to embodiments of the present disclosure, the battery cell 1 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 housed 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.

[0043] An electrode assembly 10 according to an embodiment 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 a diaphragm on top of each other.

[0044] Multiple electrodes 11 may each be provided with an electrode connector 12. Electrode 11 can be either a positive or negative electrode. A positive electrode may include an area coated with an active material layer and an uncoated area of ​​a positive electrode without active material. A negative electrode may include an area coated with an active material layer and an uncoated area of ​​a negative electrode without active material.

[0045] There can be multiple electrode connectors 12, as they are connected to each of the multiple electrodes 11. Electrode connectors 12 may include a first type of electrode connector 121 and a second type of electrode connector 122. Electrode connectors 12 can be either positive or negative. A positive connector is an electrode connector 12 connected to a positive electrode, and a negative connector is an electrode connector 12 connected to a negative electrode. Both positive and negative connectors can be connected to electrode leads 13.

[0046] The first type electrode connector 121 can be a positive or negative connector. Multiple first type electrode connectors 121 can be formed. Multiple first type electrode connectors 121 can be welded together.

[0047] The second type electrode connector 122 can be connected to one surface of the electrode lead 13. The second type electrode connector 122 can be formed to extend longer than the first type electrode connector 121. In this case, the length of the second type electrode connector 122 can be extended so that it is visible to the naked eye to be longer than the first type electrode connector 121. Of course, the length difference between the first type electrode connector 121 and the second type electrode connector 122 can be appropriately modified considering observation equipment, etc. The second type electrode connector 122 can be connected to at least one of the two surfaces of the electrode lead 13. That is, the second type electrode connector 122 can be connected to the lower surface or the upper surface of the electrode lead 13.

[0048] At this point, all of the multiple first-type electrode connectors 121 may have the same length. Here, the fact that all of the multiple first-type electrode connectors 121 have the same length can be interpreted as not only that all of the multiple first-type electrode connectors 121 have exactly the same length, but also that they have the same length in appearance. More specifically, even if there are length differences among the multiple first-type electrode connectors 121, this may mean that the difference is relatively small compared to the length difference between the first-type electrode connectors 121 and the second-type electrode connectors 122.

[0049] Reference Figure 4 The electrode assembly according to embodiments of the present disclosure may include a pair of second-type electrode connectors 122. The pair of second-type electrode connectors 122 may be connected to one side and the other side of the electrode lead 13, respectively. For example, as shown, the pair of second-type electrode connectors 122 may be connected to the upper surface and the lower surface of the electrode lead 13, respectively.

[0050] The second type electrode connector 122 is formed to be longer than the first type electrode connector 121, thereby making it easy to determine the position of the second type electrode connector 122 among a plurality of first type electrode connectors 121. Since the electrode lead 13 should be soldered to the second type electrode connector 122, the soldering position of the electrode lead 13 can be easily distinguished. After the electrode lead 13 is positioned between the second type electrode connector 122 and the first type electrode connector 121, the electrode lead 13 and the electrode connector 12 can be soldered.

[0051] The first type electrode connector 121 and the second type electrode connector 122 may each include a pair of metal layers 123 and non-metal layers 124. The first type electrode connector 121 and the second type electrode connector 122 may have an extension in which the metal layer is deposited on the non-metal layer. The extension can be formed to be thinner than an electrode connector made of metal.

[0052] The metal layers 123 are configured as a pair, and can be disposed on the outermost side. The metal layers 123 may include aluminum. The metal layers 123 can be disposed such that the electrode connectors 12 can be electrically connected to each other.

[0053] 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.

[0054] Electrode lead 13 can be connected to electrode connector 12 at the center of electrode 11 along 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 casing 20.

[0055] Electrode lead 13 can be disposed adjacent to the second type electrode connector 122. For example... Figure 2 As shown, electrode lead 13 can be located above and soldered to the second type electrode connector 122. That is, when determining the position of the soldered electrode lead 13, it has the effect of being easily determined by observing the second type electrode connector 122. However, this disclosure is not limited thereto, as... Figure 4 As shown, the second type electrode connector 122 can be positioned above the electrode lead 13. In this case, the electrode lead 13 can be positioned below the second type electrode connector 122 and soldered.

[0056] To weld the electrode lead 13, the same number of electrode connectors 12 should be provided above and below the electrode lead 13. Unless otherwise stated, it is necessary to count the number of electrode connectors. However, as mentioned above, since the forming length of the second type electrode connector 122 is different from that of the first type electrode connector 121, the position of the second type electrode connector 22 can be quickly determined, and it is easy to know where the electrode lead 13 should be provided. This has the effect of omitting the process of counting the number of electrode connectors 12.

[0057] Based on the electrode lead 13, the same number of electrode connectors 12 can be provided on both the upper and lower surfaces of the electrode lead 13. The electrode lead 13 and the second type of electrode connector 122 can be connected by welding. The electrode lead 13 can also be connected to the first type of electrode connector 121 by welding.

[0058] Electrode lead soldering method

[0059] The following will refer 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.

[0060] 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, and Figure 6 This is a flowchart of an electrode lead welding method according to another embodiment of the present disclosure.

[0061] In the following text, 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.

[0062] 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.

[0063] In step S1 of setting the electrode lead, the electrode lead 13 can be positioned at the location of the second type electrode connector 122. Since the electrode lead 13 should be positioned at the center of the electrode 11 along the thickness direction and welded, the electrode lead 13 should be positioned at the location of the second type electrode connector 122.

[0064] 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. In step S2, the number of electrode connectors 12 located below the electrode lead 13 can be greater than the number of electrode connectors 12 located above the electrode lead 13.

[0065] In the electrode lead welding method according to embodiments of the present disclosure, the electrode connector 12 may have a structure in which a metal layer 123 is deposited on a non-metal layer 124. In conventional electrode lead welding methods, the electrode leads are welded after a pre-welding step of separately welding the electrode connector, but in the method of the present disclosure, the electrode leads 13 and the electrode connector 12 can be welded in one step without performing a pre-welding step.

[0066] However, if the electrode leads 13 are concentrated and positioned on one side of the electrode connector 12 as in the conventional method, and then welded, there is a problem that welding is not possible. In this disclosure, the electrode leads 13 are positioned between the electrode connectors 12 and welded, and the electrode leads 13 are positioned at the center of the electrode 11 along the thickness direction and welded to facilitate welding. Therefore, by providing the second type of electrode connector 122, welding can be performed by appropriately positioning the electrode leads 13, thereby achieving this effect.

[0067] 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 may be embodied in various forms by those skilled in the art to which the present disclosure relates, within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

[0068] [List of reference numerals]

[0069] 1: Battery cells

[0070] 10: Electrode assembly

[0071] 11: Electrode

[0072] 12: Electrode connector

[0073] 121: Type I electrode connector

[0074] 122: Type II electrode connector

[0075] 123: Metal layer

[0076] 124: Non-metallic layer

[0077] 13: Electrode leads

[0078] 20: Battery casing

[0079] S1: Setup Steps

[0080] 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: Type 1 electrode connector; and The second type of electrode connector is attached to one surface of the electrode lead and is formed to extend longer than the first type of electrode connector.

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

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

4. The electrode assembly according to claim 3, in, The pair of metal layers are deposited on the two surfaces of the non-metal layer.

5. The electrode assembly according to claim 3, in, The non-metallic layer comprises a polymer, and The metal layer comprises aluminum.

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

7. The electrode assembly according to claim 6, in, The second type of electrode connector is configured as a pair, and The pair of second-type electrode connectors are respectively connected to one side and the other side of the electrode lead.

8. The electrode assembly according to claim 7, in, The pair of second-type electrode connectors are respectively connected to two opposite side surfaces of the electrode leads.

9. The electrode assembly according to claim 6, 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 leads and the second type of electrode connector are connected by welding.

11. The electrode assembly according to claim 1, in, The first type of electrode connector is configured in multiple ways, and The plurality of first-type electrode connectors all have the same length.

12. The electrode assembly according to claim 1, in, The plurality of electrode connectors are stacked in one direction.

13. A battery cell, the battery cell comprising: Electrode assembly; as well as The battery casing houses the electrode assembly. The electrode assembly includes: Multiple electrodes, the multiple electrodes having electrode connectors; and Electrode leads, which are connected to the electrode connector. The plurality of electrode connectors include: Type 1 electrode connector; and The second type of electrode connector is attached to one surface of the electrode lead and is formed to extend longer than the first type of electrode connector.

14. 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: Type 1 electrode connector; and A second type of electrode connector is attached to one surface of the electrode lead and is formed to extend further than the first type of electrode connector. In the step of setting the electrode leads, The electrode lead is positioned at the location of the second type of electrode connector.

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