Electrode current collector, electrode assembly comprising electrode current collector, and method for manufacturing electrode current collector

Abstract

The present invention relates to an electrode current collector, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector. The electrode current collector according to the present invention is an electrode current collector including an electrode tab extending from an end thereof and comprises: a polymer layer; and a first metal layer and a second metal layer stacked on both surfaces of the polymer layer, wherein a concave portion concave toward the polymer layer, is formed in at least one of the first metal layer or the second metal layer in the electrode tab.

Description

Electrode current collector, electrode assembly including electrode current collector, and method for manufacturing electrode current collector

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0107879, filed August 17, 2023, Korean Patent Application No. 10-2023-0107801, filed August 17, 2023, Korean Patent Application No. 10-2023-0107719, filed August 17, 2023, and Korean Patent Application No. 10-2024-0108652, filed August 13, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to an electrode current collector, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector.

[0005] Secondary batteries, unlike primary batteries, are rechargeable and have the potential for miniaturization and large capacity, leading to significant research and development in recent years. With the increasing technological development and demand for electric vehicles, energy storage systems (ESS), and mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. However, the safety of secondary batteries has not kept pace with technological advancements. To address this, methods include creating an electrical short to drain energy before secondary batteries exhibit abnormal behavior, or shorting electrical connections to improve safety.

[0006] Secondary batteries are classified into coin-shaped batteries, cylindrical batteries, square batteries, and pouch-shaped batteries, depending on the shape of the battery case. In secondary batteries, the electrode assembly mounted inside the battery case is a rechargeable power generation device composed of a laminated structure of electrodes and a separator.

[0007] Electrode assemblies can be roughly classified into a jelly-roll type in which a separator is interposed between sheet-shaped positive and negative electrodes on which an active material is applied to a current collector, a stack type in which a plurality of positive and negative electrodes are sequentially stacked with a separator interposed between them, and a stack / folding type in which stacked unit cells are wound with a long separator film.

[0008] One aspect of the present invention is to provide an electrode current collector having improved weldability, an electrode assembly including the electrode current collector, and a method for manufacturing the electrode current collector.

[0009] An electrode current collector according to an embodiment of the present invention is an electrode current collector including an electrode tab extending from an end, and including a polymer layer and a first metal layer and a second metal layer laminated on both sides of the polymer layer, wherein a concave portion may be formed in at least one of the first metal layer or the second metal layer in the electrode tab toward the polymer layer.

[0010] Meanwhile, an electrode current collector according to an embodiment of the present invention is an electrode current collector including an electrode tab extended at an end, and includes a polymer layer and a first metal layer and a second metal layer laminated on both sides of the polymer layer, and a part of the first metal layer and the second metal layer in the electrode tab forms a narrow section in which the mutual gap is narrowed, and the mutual gap between the first metal layer and the second metal layer in the narrow section may be 72% or less with respect to the thickness of the polymer layer outside the narrow section.

[0011] In addition, an electrode assembly according to an embodiment of the present invention is an electrode assembly in which electrodes and separators are alternately laminated, wherein the electrode includes an electrode current collector including an electrode tab extending at an end thereof, and the electrode current collector includes a polymer layer and a first metal layer and a second metal layer laminated on both sides of the polymer layer in a lamination direction, and a concave portion may be formed in at least one layer of the first metal layer or the second metal layer in the electrode tab toward the polymer layer.

[0012] In addition, a method for manufacturing an electrode current collector according to an embodiment of the present invention may include a lamination process for forming a laminate by laminating a first metal layer and a second metal layer on both sides of a polymer layer; a tab forming process for forming an electrode tab by notching an end portion of the laminate; and a concave portion forming process for forming a concave portion in at least one of the first metal layer and the second metal layer in the electrode tab toward the polymer layer.

[0013] According to the present invention, a concave portion is formed toward the polymer layer in the metal layer located at the portion forming the electrode tab in an electrode current collector in which a metal layer is laminated on both sides of a polymer layer, thereby significantly improving weldability.

[0014] FIG. 1 is a perspective view showing an electrode current collector according to a first embodiment of the present invention.

[0015] Figure 2 is a cross-sectional view showing an electrode tab in an electrode collector according to the first embodiment of the present invention.

[0016] Figure 3 is a perspective view showing an electrode collector according to a second embodiment of the present invention.

[0017] Fig. 4 is a cross-sectional view showing an electrode tab in an electrode collector according to a second embodiment of the present invention.

[0018] Figure 5 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention.

[0019] Figure 6 is a side view showing an electrode assembly according to an embodiment of the present invention.

[0020] Figure 7 is a perspective view showing an electrode tab of an electrode collector in an electrode assembly according to an embodiment of the present invention.

[0021] Figure 8 is a cross-sectional view showing a secondary battery including an electrode collector according to an embodiment of the present invention.

[0022] Figure 9 is a perspective view showing a lamination process in a method for manufacturing an electrode current collector according to an embodiment of the present invention.

[0023] Figure 10 is a perspective view showing a tab forming process in a method for manufacturing an electrode current collector according to an embodiment of the present invention.

[0024] Fig. 11 is a perspective view showing a process of forming a concave portion in a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0025] Fig. 12 is a cross-sectional view showing a process of forming a concave portion in a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0026] Fig. 13 is a cross-sectional view showing a process of forming a concave portion in a method for manufacturing an electrode current collector according to a second embodiment of the present invention.

[0027] Fig. 14 is a cross-sectional view showing an additional lamination process in a method for manufacturing an electrode current collector according to a second embodiment of the present invention.

[0028] Fig. 15 is a cross-sectional view showing an additional lamination process in a method for manufacturing an electrode current collector according to a second embodiment of the present invention.

[0029] Fig. 16 is a perspective view showing an electrode collector according to a third embodiment of the present invention.

[0030] Fig. 17 is a cross-sectional view showing an electrode tab in an electrode collector according to a third embodiment of the present invention.

[0031] Fig. 18 is a perspective view showing an electrode collector according to a fourth embodiment of the present invention.

[0032] Fig. 19 is a cross-sectional view showing an electrode collector according to a fourth embodiment of the present invention.

[0033] Fig. 20 is a perspective view showing an example of an electrode current collector according to a fourth embodiment of the present invention.

[0034] Fig. 21 is a perspective view showing another example of an electrode current collector according to the fourth embodiment of the present invention.

[0035] The objects, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In this specification, when reference numerals are given to components in each drawing, it should be noted that, as far as possible, identical components are given the same reference numerals even if they are shown in different drawings. Furthermore, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

[0036]

[0037] Electrode current collector according to the first embodiment

[0038] FIG. 1 is a perspective view showing an electrode current collector according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an electrode tab in an electrode current collector according to the first embodiment of the present invention.

[0039] Referring to FIGS. 1 and 2, an electrode current collector (110) according to a first embodiment of the present invention is an electrode current collector (110) including an electrode tab (111) extended at an end, and includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112).

[0040] In addition, in the electrode tab (111), some sections of the first metal layer (113) and the second metal layer (114) form a narrow section (R1) in which the mutual gap is narrowed, and the mutual gap (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 72% or less of the thickness of the polymer layer (112). Here, the narrow section refers to a section in which the mutual gap between the first metal layer (113) and the second metal layer (114) is narrowed.

[0041] In addition, a concave portion (115) facing the polymer layer (112) may be formed in at least one of the first metal layer (113) or the second metal layer (114) of the electrode tab (111).

[0042]

[0043] In more detail, the electrode current collector (110) includes an electrode tab (111) extending from an end. That is, the electrode tab (111) may be formed by notching the end of the electrode current collector (110).

[0044] In addition, the electrode current collector (110) includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112) in the lamination direction. Here, the polymer layer (112) is a layer including a polymer material, and the first metal layer (113) and the second metal layer (114) are layers including a metal material. Therefore, the electrode current collector (110) is provided in a form in which the first metal layer (113) and the second metal layer (114) are laminated on both sides of the polymer layer (112), thereby preventing a fire caused by excessive current density that occurs when the electrode current collector is made only of a metal material. In addition, the electrode current collector (110) can form a first metal layer (113) and a second metal layer (114) on both sides, so that when breaking occurs, the risk of a short due to a metal burr or the like can be reduced.

[0045] In addition, for example, the thickness (t3) of the polymer layer (112) may be 4 to 20 um. In this case, specifically, for example, the thickness (t3) of the polymer layer (112) may be 4 to 14 um.

[0046] And, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (114) may be 0.2 to 3 um. Here, specifically, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (114) may be 0.2 to 2 um.

[0047] Accordingly, the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114) can be formed to be equal to or greater than the lower limit of 0.2 μm, thereby lowering the electrical resistivity. Accordingly, the required characteristic of the current collector foil, that is, its function as an electrical connection, can be unrestricted. In other words, its function as a battery can be maintained without being impaired.

[0048] Meanwhile, the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114) are formed to be less than the upper limit of 2 μm, so that the energy density can be high. In addition, the negative effect on stability enhancement through electrical insulation during a nail test, which is a disadvantage of conventional metal foil, can be significantly reduced. Specifically, the electrode current collector (110) is provided in a form in which the first metal layer (113) and the second metal layer (114) are laminated on both sides of the polymer layer (112), so that the first metal layer (113) and the second metal layer (114) can collapse due to shrinkage of the polymer layer during the nail test, thereby enhancing safety through electrical insulation. However, if the first metal layer (113) and the second metal layer (114) are too thick, the polymer layer (112) may not be able to perform its stability enhancement function, which may deteriorate safety. Accordingly, the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114) are formed to be less than the upper limit of 2 μm, so that the polymer layer (112) including the polymer material can exhibit a stability-enhancing function. Here, the nail test is to test stability by penetrating the nail.

[0049]

[0050] Meanwhile, some sections of the first metal layer (113) and the second metal layer (114) in the electrode tab (111) form a narrow section (R1) with a narrow gap between them.

[0051] The mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be, for example, 72% or less of the thickness of the polymer layer (112). Accordingly, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be, for example, 72% or less of the thickness of the polymer layer (112), thereby improving weldability. Here, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may specifically be, for example, 50% or less of the thickness of the polymer layer (112). At this time, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be, more specifically, for example, 10 to 50% of the thickness of the polymer layer (112).

[0052] In addition, for example, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 2 to 10 μm. In this case, for example, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 2 to 8 μm. Therefore, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) is formed to be equal to or greater than the lower limit of 2 μm, so that thermal stability can be significantly improved. Meanwhile, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) is formed to be equal to or less than the upper limit of 10 μm, so that welding can be facilitated.

[0053]

[0054] And, in the electrode tab (111), a concave portion (115) is formed toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (114). That is, in the narrow section (R1), a concave portion (115) may be formed toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (114) so ​​that the mutual gap (t0) between the first metal layer (113) and the second metal layer (114) narrows. Accordingly, the thickness of the polymer layer (112) portion at the welding portion becomes thinner, and the gap between the first metal layer (113) and the second metal layer (114) is reduced, so that weldability can be improved.

[0055] The concave portion (115) may include a first concave portion (115a) formed in the first metal layer (113) and a second concave portion (115b) formed in the second metal layer (114).

[0056] The first concave portion (115a) and the second concave portion (115b) can be formed to face each other in the stacking direction.

[0057] In addition, the first concave portion (115a) and the second concave portion (115b) may be provided at positions spaced apart from each other by a certain distance. Accordingly, the first metal layer (113) and the second metal layer (114) may be provided in a spaced apart form from each other, thereby maintaining the stability effect of the metallized electrode current collector (110) in which metal layers are laminated on both sides of the polymer layer (112).

[0058] And, for example, the mutually facing distance (t0) between the first metal layer (113) portion where the first concave portion (115a) is formed and the second metal layer (114) portion where the second concave portion (115b) is formed may be 2 to 10 um. In this case, for example, the mutually facing distance (t0) between the first metal layer (113) portion where the first concave portion (115a) is formed and the second metal layer (114) portion where the second concave portion (115b) is formed may be 2 to 8 um.

[0059] Accordingly, the mutually facing distance (t0) between the first metal layer (113) portion where the first concave portion (115a) is formed and the second metal layer (114) portion where the second concave portion (115b) is formed is formed to be equal to or greater than the lower limit of 2 um, so that thermal stability can be significantly improved. Meanwhile, the mutually facing distance (t0) between the first metal layer (113) portion where the first concave portion (115a) is formed and the second metal layer (114) portion where the second concave portion (115b) is formed is formed to be equal to or less than the upper limit of 8 um, so that welding can be significantly facilitated.

[0060]

[0061] In addition, the first concave portion (115a) and the second concave portion (115b) can be formed in multiple numbers in the first metal layer (113) and the second metal layer (114), respectively.

[0062] Meanwhile, the depth (h1) in the stacking direction of the concave portion (115) may be formed to be, for example, 1 to 4 um. In this case, for example, the depth (h1) in the stacking direction of the first concave portion (115a) and the second concave portion (115b) may be formed to be, for example, 1 to 4 um, respectively.

[0063]

[0064] Referring to FIGS. 1 and 2, the electrode current collector (110) according to the first embodiment of the present invention configured as described above has the effect of significantly improving weldability by forming first and second concave portions (115a, 115b) toward the polymer layer (112) in the first and second metal layers located at the portions where the electrode tabs (111) are formed in the metalized electrode current collector (110) in which metal layers are laminated on both sides of the polymer layer (112). That is, when the electrode tabs (111) respectively provided on a plurality of electrode current collectors (110) are welded together to form an electrode assembly, the first and second concave portions (115a, 115b) toward the polymer layer (112) are formed at the welding portion, so that the thickness of the polymer layer (112) located at the welding portion is formed thinly, and the gap between the first and second metal layers is narrowed, so that the welding is significantly improved. Ultimately, when welding using a laser or ultrasonic wave, it is possible to prevent the weldability from being reduced due to the laser or ultrasonic wave not passing through the polymer layer (112).

[0065]

[0066] Electrode current collector according to the second embodiment

[0067]

[0068] Hereinafter, an electrode current collector according to a second embodiment of the present invention will be described.

[0069] FIG. 3 is a perspective view showing an electrode current collector according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view showing an electrode tab in an electrode current collector according to a second embodiment of the present invention.

[0070] Referring to FIGS. 3 and 4, an electrode current collector (210) according to a second embodiment of the present invention is an electrode current collector (210) including an electrode tab (211) extended at an end, and includes a polymer layer (112) and a first metal layer (113) and a second metal layer (214) laminated on both sides of the polymer layer (112). In addition, a portion of the first metal layer (113) and the second metal layer (214) in the electrode tab (111) forms a narrow section (R2) in which the mutual gap is narrowed, and the mutual gap (t5) between the first metal layer (113) and the second metal layer (214) in the narrow section (R2) may be 72% or less of the thickness of the polymer layer (112).

[0071] In addition, a concave portion (215) is formed toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (214) of the electrode tab (211). At this time, an additional metal layer (216) may be further laminated.

[0072] The electrode current collector according to the second embodiment of the present invention differs from the electrode current collector according to the first embodiment of the present invention described above in that an additional metal layer (216) is further provided on the outer surface of the metal layer. Therefore, in this embodiment, any overlapping content with the above-described embodiment will be omitted or briefly described, and the description will focus on the differences.

[0073]

[0074] In more detail, the electrode current collector (210) includes an electrode tab (211) extending from an end. That is, the electrode tab (211) may be formed by notching the end of the electrode current collector (210).

[0075] In addition, the electrode current collector (210) includes a polymer layer (112) in the stacking direction and a first metal layer (113) and a second metal layer (214) stacked on both sides of the polymer layer (112). Here, the polymer layer (112) is a layer including a polymer material, and the first metal layer (113) and the second metal layer (214) are layers including a metal material.

[0076] In addition, for example, the thickness (t3) of the polymer layer (112) may be 4 to 20 um. In this case, specifically, for example, the thickness (t3) of the polymer layer (112) may be 4 to 14 um.

[0077] And, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (214) may be 0.2 to 3 um. Here, specifically, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (214) may be 0.2 to 2 um.

[0078]

[0079] Meanwhile, in the electrode tab (111), some sections of the first metal layer (113) and the second metal layer (214) form a narrow section (R2) in which the mutual gap is narrowed. The mutual gap (t5) between the first metal layer (113) and the second metal layer (214) in the narrow section (R1) may be, for example, 72% or less of the thickness of the polymer layer (112). Here, the mutual gap (t5) between the first metal layer (113) and the second metal layer (214) in the narrow section (R2) may be, for example, 50% or less of the thickness of the polymer layer (112). At this time, the mutual gap (t0) between the first metal layer (113) and the second metal layer (214) in the narrow section (R1) may be, more specifically, 10 to 50% of the thickness of the polymer layer (112).

[0080] In addition, for example, the mutual spacing (t5) between the first metal layer (113) and the second metal layer (214) in the narrow section (R2) may be 2 to 10 μm. In this case, for example, specifically, the mutual spacing (t5) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 2 to 8 μm.

[0081]

[0082] And, in the electrode tab (211), a concave portion (215) is formed toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (214). That is, in the narrow section (R2), a concave portion (215) may be formed toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (214) so ​​that the mutual gap (t5) between the first metal layer (113) and the second metal layer (214) becomes narrow.

[0083] At this time, a concave portion (215) may be formed in the first metal layer (113) of the electrode tab (211). Accordingly, the thickness of the polymer layer (112) portion at the welding portion may be reduced, and the gap between the first metal layer (113) and the second metal layer (214) may be reduced, thereby improving weldability. In addition, the concave portion (215) and the second metal layer (214) may be provided at positions spaced apart from each other by a certain distance.

[0084] The mutually facing gap (t5) between the portion where the concave portion (215) is formed in the first metal layer (113) and the second metal layer (214) can be 2 to 10 um.

[0085] Accordingly, the mutually facing distance (t5) between the portion where the concave portion (215) is formed in the first metal layer (113) and the second metal layer (214) is formed to be equal to or greater than the lower limit of 2 um, so that the effect of preventing fire caused by excessive current density of the electrode current collector (110) in which the first metal layer (113) and the second metal layer (114) are laminated on both sides of the polymer layer (112) can be implemented. That is, the mutually facing distance (t5) between the portion where the concave portion (215) is formed in the first metal layer (113) and the second metal layer (214) is formed to be equal to or greater than the lower limit of 2 um, so that thermal stability can be significantly improved.

[0086] Meanwhile, the gap (t5) between the portion where the concave portion (215) is formed in the first metal layer (113) and the second metal layer (214) facing each other is formed to be less than the upper limit of 8 um, so that welding can be significantly facilitated.

[0087] In addition, a plurality of concave portions (215) can be formed in the first metal layer (113).

[0088] Meanwhile, the depth in the stacking direction of the concave portion (215) can be formed to be 1 to 4 um.

[0089]

[0090] An additional metal layer (216) may be laminated on the outer surface of the first metal layer (113). Here, the additional metal layer (216) may be positioned on the electrode tab (211).

[0091] At this time, the thickness (t4) of the additional metal layer (216) can be formed to be 0.2 to 2 um.

[0092] In addition, the additional metal layer (216) may further include a protrusion (216a) that protrudes corresponding to the concave portion (215). At this time, for example, the height (h2) of the protrusion (216a) in the lamination direction may be formed to be 1 to 4 um.

[0093] Therefore, when welding a metalized electrode current collector, weldability can be significantly improved by laminating an additional metal layer (216) on the outer surface of the first metal layer (113). That is, weldability between electrode tabs (211) and weldability between electrode tabs (211) and electrode leads can be significantly improved.

[0094]

[0095] Referring to FIGS. 3 and 4, the electrode current collector (210) according to the second embodiment of the present invention configured as described above has a concave portion (215) formed toward the polymer layer (112) in the first metal layer (113) located at the portion where the electrode tabs (211) are formed in the metalized electrode current collector (210) in which metal layers are laminated on both sides of the polymer layer (112), thereby improving weldability. That is, when the electrode tabs (211) respectively provided on a plurality of electrode current collectors (210) are mutually welded and the electrode tabs (211) and the electrode leads are welded, the concave portion (215) is formed toward the polymer layer (112) at the welding portion, so that the thickness of the polymer layer (112) located at the welding portion is formed thinly, and the gap between the first and second metal layers is narrowed, so that the welding is performed remarkably well. Ultimately, when welding using laser or ultrasonic waves, it is possible to prevent the weldability from being reduced due to the laser or ultrasonic waves not being able to pass through the polymer layer (112). In particular, by further laminating an additional metal layer (216) on the outer surface of the first metal layer (113), the weldability is significantly improved.

[0096]

[0097] Electrode assembly according to the embodiment

[0098]

[0099] Hereinafter, an electrode assembly according to an embodiment of the invention will be described.

[0100] FIG. 5 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention, and FIG. 6 is a side view showing an electrode assembly according to an embodiment of the present invention.

[0101] Referring to FIGS. 1, 2, 5, and 6, an electrode assembly (100) according to an embodiment of the present invention is an electrode assembly (100) in which electrodes (130) and separators (140) are alternately laminated, wherein the electrode (130) includes an electrode current collector (110) including an electrode tab (111) extending from an end thereof, and the electrode current collector (110) includes a polymer layer (112) in a lamination direction and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112), and a concave portion (115) is formed in at least one of the first metal layer (113) or the second metal layer (114) in the electrode tab (111) toward the polymer layer (112).

[0102] An electrode assembly (100) according to an embodiment of the present invention relates to an electrode assembly (100) including an electrode collector (110) according to the first embodiment described above and an electrode collector (110) according to the second embodiment described above. Therefore, in this embodiment, overlapping content with the above-described embodiment is omitted or briefly described, and differences are described.

[0103]

[0104] In more detail, the electrode assembly (100) according to an embodiment of the present invention is a power plant capable of charging and discharging, and forms a structure in which electrodes (130) and separators (140) are combined and alternately laminated.

[0105] The electrode (130) includes an electrode current collector (110) including an electrode tab (111) extending from one end.

[0106] Here, the electrode (130) may include an electrode current collector (110) and an electrode active material (120) coated on one or both sides of the electrode current collector (110). At this time, the electrode (130) may be formed with a holding region where the electrode active material (120) is coated on the electrode current collector (110) and a non-coated region where the electrode active material (120) is not coated on the electrode current collector (110). At this time, an electrode tab (111) may be positioned in the non-coated region of the electrode current collector (110).

[0107] The electrode current collector (110) may include a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112) in the lamination direction. At this time, a concave portion (115) is formed in at least one layer of the first metal layer (113) or the second metal layer (114) in the electrode tab (111) toward the polymer layer (112).

[0108] Meanwhile, the polymer layer (112) may be formed of a material including, for example, PET (polyethylene terephthalate), PI (polyimide), or EN (polyethylenenaphthalate).

[0109]

[0110] FIG. 7 is a perspective view showing an electrode tab of an electrode current collector in an electrode assembly according to an embodiment of the present invention, and FIG. 8 is a cross-sectional view showing a secondary battery including an electrode current collector according to an embodiment of the present invention.

[0111] Meanwhile, referring to FIGS. 5 to 8, the electrode assembly (100) may include a plurality of electrodes (130) and a separator (140) stacked thereon. At this time, the electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) are gathered and welded together, and the concave portion (115) may be positioned at the welding portion (R) of the electrode tabs (111). At this time, the electrode lead may be welded together at the welding portion (R). Accordingly, when welding the metalized electrode current collector (110), the concave portion (115) may be positioned at the welding portion (R) of the electrode tabs (111), so that the weldability may be significantly improved. That is, the weldability between the electrode tabs (111) and the weldability between the electrode tabs (111) and the electrode lead may be significantly improved.

[0112]

[0113] Meanwhile, the electrode (130) may include an anode (130a) and a cathode (130b). In addition, the separator (140) electrically insulates the anode (130a) and the cathode (130b) by separating them.

[0114] The positive electrode (130a) may include a positive electrode current collector (110a) and a positive electrode active material (120a) provided on one surface of the positive electrode current collector (110a). In this case, the positive electrode (130a) may include a positive electrode non-laminated region, which is a region where the positive electrode active material (120a) is not laminated.

[0115] The positive electrode active material (120a) may be composed of lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a compound or mixture containing one or more of these.

[0116] The negative electrode (130b) may include a negative electrode current collector (110b) and a negative electrode active material (120b) provided on one surface of the negative electrode current collector (110b). At this time, the negative electrode (130b) may include a negative electrode non-laminated region, which is a region where the negative electrode active material (120b) is not laminated.

[0117] The negative electrode active material (120b) may be formed of, for example, artificial graphite, lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, silicon compound, tin compound, titanium compound, or an alloy thereof. In this case, the negative electrode active material (120b) may further include, for example, non-graphite SiO (silica) or SiC (silicon carbide).

[0118] Meanwhile, the positive electrode current collector (110a) and the negative electrode current collector (110b) may include a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112) in the lamination direction.

[0119] At this time, the first metal layer (113) and the second metal layer (114) located on the positive electrode collector (110a) may include an aluminum material, and the first metal layer (113) and the second metal layer (114) located on the negative electrode collector (110b) may include a copper material.

[0120]

[0121] Meanwhile, referring to FIG. 2, for example, the concave portion (115) may be formed in the first metal layer (113) and the second metal layer. That is, the concave portion (115) may include a first concave portion (115a) formed in the first metal layer (113) and a second concave portion (115b) formed in the second metal layer.

[0122] Referring to Fig. 4, as another example, a concave portion (215) may be formed on the first metal layer (113). At this time, an additional metal layer (216) may be further laminated on the outer surface of the first metal layer (113). Here, the additional metal layer (216) may be positioned on the electrode tab (211).

[0123]

[0124] Meanwhile, referring to FIG. 8, a secondary battery (10) can be manufactured including an electrode assembly (100) according to an embodiment of the present invention configured as described above. That is, the electrode assembly (100) can be accommodated in a pouch (20) to form a secondary battery (10). At this time, the secondary battery (10) can be formed by further including an electrode lead (30) that is connected to the electrode assembly (100) and electrically connects it to the outside of the pouch (20).

[0125]

[0126] Method for manufacturing an electrode current collector according to the first embodiment

[0127]

[0128] Hereinafter, a method for manufacturing an electrode current collector according to the first embodiment of the present invention will be described.

[0129] FIG. 9 is a perspective view showing a lamination process in a method for manufacturing an electrode current collector according to an embodiment of the present invention, FIG. 10 is a perspective view showing a tab forming process in a method for manufacturing an electrode current collector according to an embodiment of the present invention, and FIG. 11 is a perspective view showing a concave portion forming process in a method for manufacturing an electrode current collector according to a first embodiment of the present invention.

[0130] Referring to FIGS. 9 to 11, a method for manufacturing an electrode current collector according to a first embodiment of the present invention is a method for manufacturing an electrode current collector, and includes a lamination process for forming a laminate (S) by laminating a first metal layer (113) and a second metal layer (114) on both sides of a polymer layer (112), a tab forming process for forming an electrode tab (111) by notching an end portion of the laminate (S), and a concave portion forming process for forming a concave portion (115) toward the polymer layer (112) in at least one layer of the first metal layer (113) or the second metal layer (114) in the electrode tab (111). At this time, the concave portion forming process may form a narrow section (R1) in which a portion of the first metal layer (113) and the second metal layer (114) in the electrode tab (111) is spaced narrowly apart from each other.

[0131] The method for manufacturing an electrode current collector according to the first embodiment of the present invention relates to a method for manufacturing an electrode current collector for manufacturing an electrode current collector included in an electrode assembly according to the first embodiment of the present invention and the present invention.

[0132] Therefore, in the embodiment of the electrode current collector manufacturing method according to the first embodiment of the present invention, the overlapping contents with the embodiments of the present invention described above are omitted or briefly described, and the differences are described.

[0133]

[0134] In more detail, referring to FIG. 9, the lamination process forms a laminate (S) by laminating a first metal layer (113) and a second metal layer (114) on both sides of a polymer layer (112).

[0135] In addition, the lamination process can laminate the first metal layer (113) and the second metal layer (114) on both sides of the polymer layer (112) through deposition or lamination.

[0136]

[0137] Referring to Fig. 10, the tab forming process forms an electrode tab (111) by notching the end portion of the laminate (S).

[0138]

[0139] That is, the tab forming process can form an electrode tab (111) in a protruding shape by cutting one side of a laminate (S) in which a first metal layer (113) and a second metal layer (114) are laminated on both sides of a polymer layer (112).

[0140] Additionally, the tab forming process can be performed by notching the electrode tab (111) in the laminate (S) using a punch die or laser.

[0141]

[0142] Fig. 12 is a cross-sectional view showing a process of forming a concave portion in a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0143] Referring to FIGS. 2, 11, and 12, the concave portion forming process forms a concave portion (115) toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (114) in the electrode tab (111). Accordingly, the concave portion forming process can form a narrow section (R1) in which a portion of the first metal layer (113) and the second metal layer (114) in the electrode tab (111) has a narrowed gap. At this time, the gap (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) can be, for example, 72% or less of the thickness of the polymer layer (112). And, for example, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 2 to 10 um. In this case, for example, specifically, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be 2 to 8 m.

[0144]

[0145] In addition, the concave portion forming process may include a first pressing step of pressing a part of the first metal layer (113) with a pressing means (P) to form a first concave portion (115a), and a second pressing step of pressing a part of the second metal layer (114) with the pressing means (P) to form a second concave portion (115b). Here, the pressing means (P) may be, for example, a plunger. At this time, the concave portion forming process may form a concave portion (115) with a circular cross-section by using a plunger whose end is formed in a cylindrical shape.

[0146] In addition, the process of forming a concave portion may be performed by simultaneously performing the first pressing step and the second pressing step, and the first concave portion (115a) and the second concave portion (115b) may be formed to face each other at positions spaced apart from each other by a certain distance.

[0147] In addition, the process of forming a concave portion can form a plurality of first concave portions (115a) and second concave portions (115b) in the first metal layer (113) and the second metal layer (114), respectively.

[0148] Here, the process of forming a concave portion can be performed by forming a depth (h1) of, for example, 1 to 4 um in the stacking direction of the concave portion (115). Specifically, for example, the depth (h1) in the stacking direction of the first concave portion (115a) and the second concave portion (115b) can each be formed to be 1 to 4 um.

[0149]

[0150] Method for manufacturing an electrode current collector according to the second embodiment

[0151]

[0152] Hereinafter, a method for manufacturing an electrode current collector according to a second embodiment of the present invention will be described.

[0153] Fig. 13 is a cross-sectional view showing a process of forming a concave portion in a method for manufacturing an electrode current collector according to a second embodiment of the present invention, Fig. 14 is a cross-sectional view showing an additional lamination process in a method for manufacturing an electrode current collector according to a second embodiment of the present invention, and Fig. 15 is a cross-sectional view showing an additional lamination process in a method for manufacturing an electrode current collector according to a second embodiment of the present invention. Here, Fig. 13(a) shows a state before forming a concave portion, and Fig. 13(b) shows a state after the concave portion has been formed.

[0154] Referring to FIGS. 9, 10, and 13 to 15, a method for manufacturing an electrode current collector according to a second embodiment of the present invention is a method for manufacturing an electrode current collector, which includes a lamination process for forming a laminate (S) by laminating a first metal layer (113) and a second metal layer (214) on both sides of a polymer layer (112), a tab forming process for forming an electrode tab (211) by notching an end portion of the laminate (S), and a concave portion forming process for forming a concave portion (215) in the electrode tab (211) toward the polymer layer (112) in at least one layer of the first metal layer (113) or the second metal layer (214). Here, the concave portion forming process may form a narrow section (R2) in which a portion of the first metal layer (113) and the second metal layer (214) in the electrode tab (211) is spaced apart from each other. Meanwhile, after the concave portion formation process, an additional lamination process of further laminating an additional metal layer (216) may be included.

[0155] The method for manufacturing an electrode current collector according to the second embodiment of the present invention relates to a method for manufacturing an electrode current collector for manufacturing an electrode current collector (210) according to the second embodiment of the present invention described above and an electrode current collector included in an electrode assembly according to the embodiment of the present invention.

[0156] Therefore, in the embodiment of the electrode current collector manufacturing method according to the second embodiment of the present invention, overlapping contents with the embodiments of the present invention described above are omitted or briefly described, and differences are described.

[0157]

[0158] In more detail, referring to FIG. 9, the lamination process forms a laminate (S) by laminating a first metal layer (113) and a second metal layer (214) on both sides of a polymer layer (112).

[0159] In addition, the lamination process can be performed by depositing or laminating the first metal layer (113) and the second metal layer (214) on both sides of the polymer layer (112). At this time, for example, the lamination process can be performed by depositing the first metal layer (113) and the second metal layer (214) on both sides of the polymer layer (112).

[0160]

[0161] Referring to Fig. 10, the tab forming process forms an electrode tab (211) by notching the end portion of the laminate (S).

[0162] That is, the tab forming process can form an electrode tab (211) in a protruding shape by cutting one side of a laminate (S) in which a first metal layer (113) and a second metal layer (214) are laminated on both sides of a polymer layer (112).

[0163] Additionally, the tab forming process can be performed by notching the electrode tab (211) in the laminate (S) using a punch die or laser.

[0164]

[0165] Referring to FIGS. 10 and 13, the concave portion forming process forms a concave portion (215) toward the polymer layer (112) in at least one of the first metal layer (113) or the second metal layer (214) in the electrode tab (211). Accordingly, the concave portion forming process can form a narrow section (R2) in which a portion of the first metal layer (113) and the second metal layer (114) in the electrode tab (211) has a narrow gap. At this time, the gap (t5) between the first metal layer (113) and the second metal layer (114) in the narrow section (R2) can be, for example, 72% or less of the thickness of the polymer layer (112). And, for example, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (214) in the narrow section (R2) may be 2 to 10 um. In this case, for example, specifically, the mutual spacing (t0) between the first metal layer (113) and the second metal layer (214) in the narrow section (R2) may be 2 to 8 m.

[0166]

[0167] In addition, the process of forming a concave portion may include a pressing step of pressing a portion of the first metal layer (113) toward the polymer layer (112) with a pressing means (P) to form a concave portion (215).

[0168] The pressurizing step can form the concave portion (215) so that the concave portion (215) and the second metal layer (214) are positioned at a certain distance apart from each other.

[0169]

[0170] In the additional lamination process, after the concave portion formation process, an additional metal layer (216) can be further laminated on the outer surface of the first metal layer (113).

[0171] Additionally, the additional lamination process can laminate an additional metal layer (216) so that it is positioned on the electrode tab (211).

[0172] In addition, the additional lamination process can form the thickness (t4) of the additional metal layer (216) to 0.2 to 2 um.

[0173] In addition, the additional lamination process can further form a protrusion (216a) corresponding to the concave portion (215) in the additional metal layer (216). At this time, for example, the height of the protrusion (216a) in the lamination direction can be formed to be 1 to 4 um.

[0174]

[0175] Meanwhile, for example, an additional lamination process can be formed by laminating an additional metal layer (216) with the first metal layer (113) by applying heat and pressure.

[0176] And, as another example, the additional lamination process can be formed by depositing an additional metal layer (216) on the outer surface of the first metal layer (113).

[0177]

[0178] While the present invention has been described in detail through specific examples, these are intended to illustrate the invention in detail and are not intended to be limiting. Those skilled in the art will appreciate that various implementations are possible within the technical scope of the present invention.

[0179] Additionally, the specific scope of protection of the invention will be made clear by the appended claims.

[0180]

[0181] Electrode current collector according to the third embodiment

[0182]

[0183] Fig. 16 is a perspective view showing an electrode collector according to a third embodiment of the present invention, and Fig. 17 is a cross-sectional view showing an electrode tab in an electrode collector according to a third embodiment of the present invention.

[0184] Referring to FIGS. 16 and 17, an electrode current collector (310) according to a third embodiment of the present invention is an electrode current collector (310) including an electrode tab (311) extended at an end, and includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112).

[0185] In addition, some sections of the first metal layer (113) and the second metal layer (114) in the electrode tab (311) form a narrow section (R3) in which the mutual gap is narrowed, and the mutual gap (t0') of the first metal layer (113) and the second metal layer (114) in the narrow section (R3) may be 72% or less of the thickness (t3') of the polymer layer (112).

[0186] Additionally, at least one of the first metal layer (113) or the second metal layer (114) in the electrode tab (311) includes a metal wedge (315) inserted into the polymer layer (112).

[0187] The electrode current collector (310) according to the third embodiment of the present invention has a difference in that the metal stud (315) is positioned in at least one layer of the first metal layer (113) or the second metal layer (114) compared to the electrode current collector according to the first and second embodiments of the present invention described above. Therefore, in this embodiment, overlapping content with the above-described embodiments is omitted or briefly described, and the description focuses on the differences.

[0188]

[0189] In more detail, the electrode current collector (310) includes an electrode tab (311) extending from an end. That is, the electrode tab (311) may be formed by notching the end of the electrode current collector (310).

[0190] In addition, the electrode current collector (310) includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112) in the lamination direction. Here, the polymer layer (112) is a layer including a polymer material, and the first metal layer (113) and the second metal layer (114) are layers including a metal material. Therefore, the electrode current collector (310) is provided in a form in which the first metal layer (113) and the second metal layer (114) are laminated on both sides of the polymer layer (112), thereby preventing a fire caused by excessive current density that occurs when the electrode current collector is made only of a metal material. In addition, the electrode current collector (310) can form the first metal layer (113) and the second metal layer (114) on both sides, so that the risk of short circuit due to metal burr or the like when breaking occurs can be reduced.

[0191] In addition, for example, the thickness (t3') of the polymer layer (112) may be 2 to 14 um, and the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114) may be 0.2 to 3 um.

[0192]

[0193] A metal wedge (315) is positioned by being inserted into at least one of the first metal layer (113) or the second metal layer (114) from the electrode tab (311) up to the polymer layer (112). At this time, the height (g1) of the metal wedge (315) inserted into the first metal layer (113) or the second metal layer (114) may be greater than the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114).

[0194] Additionally, the metal wedge (315) may include a metal material. In addition, the metal wedge (315) may include, for example, the same material as the material of the first metal layer (113) and the second metal layer (114).

[0195] In addition, the metal wedge (315) may include a plurality of first metal wedges (315a) positioned on the first metal layer (113) and a plurality of second metal wedges (315b) positioned on the second metal layer (114).

[0196] Here, the first metal wedge (315a) and the second metal wedge (315b) can be positioned at a certain distance apart from each other.

[0197] In addition, the mutual spacing (t0') between the first metal wedge (315a) and the second metal wedge (315b) may be 2 to 10 um. That is, the mutual spacing (t0') between the first metal layer (113) and the second metal layer (114) in the narrow section (R3) may be 2 to 10 um.

[0198] Accordingly, the mutual spacing (t0') between the first metal wedge (315a) and the second metal wedge (315b) is formed to be equal to or greater than the lower limit of 2 um, so that the effect of preventing fire caused by excessive current density of the electrode current collector (310) in which the first metal layer (113) and the second metal layer (114) are laminated on both sides of the polymer layer (112) can be implemented. That is, the mutual spacing (t0') between the first metal wedge (315a) and the second metal wedge (315b) is formed to be equal to or greater than the lower limit of 2 um, so that thermal stability can be significantly improved.

[0199] Meanwhile, the mutual spacing (t0') between the first metal wedge (315a) and the second metal wedge (315b) is formed to be less than the upper limit of 10 um, so that welding is significantly easier and conductivity can be significantly increased.

[0200]

[0201] Meanwhile, some sections of the first metal layer (113) and the second metal layer (114) in the electrode tab (311) form a narrow section (R3) with a narrow gap between them.

[0202] The mutual spacing (t0') between the first metal layer (113) and the second metal layer (114) in the narrow section (R3) may be, for example, 72% or less of the thickness (t3') of the polymer layer (112). Accordingly, the mutual spacing (t0') between the first metal layer (113) and the second metal layer (114) in the narrow section (R3) may be, for example, 72% or less of the thickness (t3') of the polymer layer (112), thereby improving weldability. Here, the mutual spacing (t0') between the first metal layer (113) and the second metal layer (114) in the narrow section (R3) may specifically be, for example, 50% or less of the thickness (t3') of the polymer layer (112). At this time, the mutual spacing (t0') between the first metal layer (113) and the second metal layer (114) in the narrow section (R1) may be, more specifically, for example, 10 to 50% of the thickness (t3') of the polymer layer (112).

[0203]

[0204] In addition, as a first example of the electrode tab (311), the first metal wedge (315a) and the second metal wedge (315b) may be positioned parallel to each other in the stacking direction. Here, in one example of the electrode tab (311), the thicknesses (t1, t2) of the first metal layer (113) and the second metal layer (114) may be the same. At this time, for example, the thickness (t3') of the first metal layer (113) and the second metal layer (114) may be 0.5 to 1 um.

[0205] Meanwhile, as a second example of the electrode tab (311), the first metal wedge (315a) and the second metal wedge (315b) in the metal wedge (315) may be positioned alternately in the stacking direction.

[0206] Meanwhile, as a third example of the electrode tab (311), the thickness (t1) of the first metal layer (113) and the thickness (t2) of the second metal layer (114) may be formed to be different from each other. In this case, the metal wedge (315) may be provided on the second metal layer (114).

[0207]

[0208] Referring to FIGS. 16 and 17, the electrode current collector (310) according to the third embodiment of the present invention configured as described above has the effect of significantly improving weldability by inserting a metal wedge (315) into the metal layer located at the portion where the electrode tab (311) is formed in the metalized electrode current collector (310) in which metal layers are laminated on both sides of the polymer layer (112). That is, when the electrode tabs (311) respectively provided on a plurality of electrode current collectors (310) are welded to each other to form an electrode assembly and when the electrode tabs (311) and the electrode leads are welded, the metal wedge (315) is inserted into the welding portion up to the polymer layer (112), so that the thickness (t3') of the polymer layer (112) portion is formed thin, and as the gap between the metal portions located on both sides of the polymer layer (112) is narrowed, there is the effect of significantly improving welding. Ultimately, when welding using a laser or ultrasonic wave, it is possible to prevent the weldability from being reduced due to the laser or ultrasonic wave not passing through the polymer layer (112).

[0209]

[0210] Electrode current collector according to the fourth embodiment

[0211]

[0212] Fig. 18 is a perspective view showing an electrode collector according to a fourth embodiment of the present invention, and Fig. 19 is a cross-sectional view showing an electrode collector according to a fourth embodiment of the present invention.

[0213] Referring to FIGS. 18 and 19, an electrode current collector (410) according to a fourth embodiment of the present invention is an electrode current collector (410) including an electrode tab (411) extended at an end, and includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112).

[0214] In addition, some sections of the first metal layer (113) and the second metal layer (114) in the electrode tab (411) form a narrow section (R4) in which the mutual gap is narrowed, and the mutual gap (t0”) between the first metal layer (113) and the second metal layer (114) in the narrow section (R4) may be 72% or less of the thickness (t3”) of the polymer layer (112).

[0215] Additionally, in the electrode tab (411), the second metal layer (114) includes a metal rib (415) extending to the polymer layer (112).

[0216] The electrode current collector (410) according to the fourth embodiment of the present invention has a difference in that, compared to the electrode current collectors according to the first to third embodiments of the present invention described above, a metal rib (415) extending to the polymer layer is provided on the second metal layer (114). Therefore, in this embodiment, overlapping content with the above-described embodiments is omitted or briefly described, and the description focuses on the differences.

[0217]

[0218] In more detail, the electrode current collector (410) includes an electrode tab (411) extending from an end. That is, the electrode tab (411) may be formed by notching the end of the electrode current collector (410).

[0219] In addition, the electrode current collector (410) includes a polymer layer (112) and a first metal layer (113) and a second metal layer (114) laminated on both sides of the polymer layer (112) in the lamination direction (D). Here, the polymer layer (112) is a layer including a polymer material, and the first metal layer (113) and the second metal layer (114) are layers including a metal material.

[0220] Additionally, for example, the thickness (t3”) of the polymer layer (112) may be 2 to 14 um.

[0221] And, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (114) may be 0.2 to 3 um. Here, specifically, for example, the thickness (t1, t2) of the first metal layer (113) and the second metal layer (114) may be 0.2 to 2 um.

[0222] Meanwhile, the thickness (t1) of the first metal layer (113) may be, for example, the same as the thickness (t2) of the second metal layer (114).

[0223] Additionally, the thickness (t1) of the first metal layer (113) may be thicker than the thickness (t2) of the second metal layer (114), for example. Accordingly, the electrode current collector (410) may be easily manufactured.

[0224]

[0225] The metal rib (415) may be provided to extend from the electrode tab to the polymer layer (112) in the second metal layer (114).

[0226] Additionally, the metal rib (415) may protrude from the inner surface of the second metal layer (114) to the polymer layer (112) and may be formed along the inner surface of the second metal layer (114).

[0227] Additionally, the metal rib (415) may include the same material as the material of the first metal layer (113) and the second metal layer (114).

[0228]

[0229] Fig. 20 is a perspective view showing a main part of an example of an electrode current collector according to a fourth embodiment of the present invention, and Fig. 21 is a perspective view showing a main part of another example of an electrode current collector according to a fourth embodiment of the present invention.

[0230] Referring to FIG. 20, in the electrode tab (411) of the electrode collector (410), a metal rib (415) may be formed in the shape of a rectangular wall, for example, and may be provided in multiple pieces at regular intervals.

[0231] Referring to FIG. 21, in the electrode tab (411') of the electrode collector (410'), the metal rib (415') may be provided in the form of multiple cylinders, as another example.

[0232]

[0233] Meanwhile, referring to FIG. 19, the end of the metal rib (415) may be spaced apart from the first metal layer (113) by a certain distance.

[0234] Accordingly, the end of the metal rib (415) is spaced apart from the first metal layer (113) by a certain distance, so that the first metal layer (113) and the second metal layer (114) are not connected, and thus the stability effect of the metallized electrode current collector (410) in which the metal layer is laminated on both sides of the polymer layer (112) can be maintained.

[0235]

[0236] In addition, the distance between the end of the metal rib (415) and the first metal layer (113) may be 2 to 8 um. That is, the distance (t0") between the first metal layer (113) and the second metal layer (114) in the narrow section (R4) may be 2 to 10 um. Accordingly, the distance (t0") between the end of the metal rib (415) and the first metal layer (113) may be formed to be equal to or greater than the lower limit of 2 um, so that thermal stability may be significantly improved. Meanwhile, the distance (t0") between the end of the metal rib (415) and the first metal layer (113) may be equal to or less than the upper limit of 8 um, so that welding may be significantly facilitated.

[0237]

[0238] Referring to FIGS. 18 and 19, the electrode current collector (410) according to the fourth embodiment of the present invention configured as described above is provided with a metal rib (415) extending toward the polymer layer (112) in the metal layer located at the portion forming the electrode tab (411) in the electrode current collector (410) in which a metal layer is laminated on both sides of the polymer layer (112), thereby significantly improving weldability. That is, when welding the electrode tabs (411) provided on each of a plurality of electrode current collectors (410) to each other to form an electrode assembly and welding the electrode tabs (411) and the electrode leads, the metal rib (415) extends toward the polymer layer (112) at the welding portion, so that the thickness (t3”) of the polymer layer (112) located at the welding portion is formed thin, and the gap between the first and second metal layers (113, 114) is narrowed, so that there is an effect of significantly improving welding. Ultimately, when welding using a laser or ultrasonic waves, it is possible to prevent the weldability from being deteriorated due to the laser or ultrasonic waves not being able to pass through the polymer layer (112).

[0239]

[0240] [Explanation of symbols]

[0241] 10: Secondary batteries

[0242] 20: Pouch

[0243] 30: Electrode lead

[0244] 100: Electrode assembly

[0245] 110,310,410: Electrode current collector

[0246] 110a: positive current collector

[0247] 110b: Negative current collector

[0248] 111,211,311,411: Electrode tab

[0249] 112: Polymer layer

[0250] 113: First metal layer

[0251] 114, 214: Second metal layer

[0252] 115, 215: Concave

[0253] 115a: First concave

[0254] 115b: Second concave

[0255] 120: Electrode active material

[0256] 120a: Positive electrode active material

[0257] 120b: Negative active material

[0258] 130: Electrode

[0259] 130a: positive pole

[0260] 130b: cathode

[0261] 140: Membrane

[0262] 216: Additional metal layer

[0263] 216a: Protrusion

[0264] 315: Metal wedge

[0265] 315a: First metal wedge

[0266] 315b: Second metal wedge

[0267] 415, 415': Metal rib

[0268] P: Pressurizing means

[0269] R: Welding area

[0270] S: Laminate

Claims

1. An electrode current collector including an electrode tab extended at one end, It comprises a polymer layer and a first metal layer and a second metal layer laminated on both sides of the polymer layer, An electrode current collector in which a concave portion is formed toward the polymer layer in at least one of the first metal layer and the second metal layer in the electrode tab.

2. In claim 1, The above concave part An electrode current collector including a first concave portion formed in the first metal layer; and a second concave portion formed in the second metal layer.

3. In claim 2, An electrode current collector in which the first concave portion and the second concave portion are formed to face each other in the stacking direction.

4. In claim 3, An electrode current collector in which the first concave portion and the second concave portion are provided at positions spaced apart from each other by a certain distance.

5. In claim 4, An electrode current collector in which the mutually facing distance between the first metal layer portion where the first concave portion is formed and the second metal layer portion where the second concave portion is formed is 2 to 8 um.

6. In claim 2, An electrode current collector in which the first concave portion and the second concave portion are formed in multiple numbers in the first metal layer and the second metal layer, respectively.

7. In claim 1, An electrode current collector formed with a depth of 1 to 4 um in the lamination direction of the above concave portion.

8. In any one of claims 1 to 7, The thickness of the above polymer layer is 4 to 14 um, An electrode current collector formed with a thickness of the first metal layer and the second metal layer of 0.2 to 2 um.

9. In claim 1, The above concave portion is formed in the first metal layer, An electrode current collector further comprising an additional metal layer laminated on an outer surface of the first metal layer.

10. In claim 9, The thickness of the first metal layer and the second metal layer is formed to be 0.2 to 2 um, An electrode current collector formed with the thickness of the above additional metal layer being 0.2 to 2 um.

11. In claim 9, An electrode current collector in which the above concave portion and the second metal layer are provided at positions spaced apart from each other at a certain distance.

12. In claim 11, An electrode current collector in which the mutually facing distance between the portion where the concave portion is formed in the first metal layer and the second metal layer is 2 to 10 um.

13. In claim 9, The above additional metal layer is an electrode current collector positioned on the electrode tab.

14. In claim 9, An electrode current collector, wherein the additional metal layer further includes a protrusion corresponding to the concave portion.

15. In claim 14, An electrode current collector formed with a height of 1 to 4 um in the stacking direction.

16. An electrode current collector including an electrode tab extended at a terminal end, It comprises a polymer layer and a first metal layer and a second metal layer laminated on both sides of the polymer layer, In the above electrode tab, some sections of the first metal layer and the second metal layer form a narrow section with a narrow gap between them, An electrode current collector in which the mutual spacing between the first metal layer and the second metal layer in the narrow section is 72% or less of the thickness of the polymer layer outside the narrow section.

17. In claim 16, An electrode current collector in which the mutual spacing between the first metal layer and the second metal layer in the narrow section is 2 to 10 um.

18. In claim 16, An electrode current collector in which a concave portion is formed toward the polymer layer in at least one of the first metal layer or the second metal layer so that the gap between the first metal layer and the second metal layer in the narrow section is narrowed.

19. In claim 16, An electrode current collector, wherein at least one of the first metal layer and the second metal layer includes a metal wedge inserted into the polymer layer so that the gap between the first metal layer and the second metal layer in the narrow section is narrowed.

20. In claim 16, An electrode current collector, wherein the second metal layer includes a metal rib extending into the polymer layer so that the gap between the first metal layer and the second metal layer in the narrow section is narrowed.

21. An electrode assembly in which electrodes and separators are alternately laminated, The above electrode comprises an electrode collector including an electrode tab extending from one end thereof, The above electrode collector It comprises a polymer layer in the lamination direction and a first metal layer and a second metal layer laminated on both sides of the polymer layer, An electrode assembly in which a concave portion is formed toward the polymer layer in at least one of the first metal layer and the second metal layer in the electrode tab.

22. In claim 21, The above electrode assembly comprises a plurality of electrodes and a separator laminated together, The electrode tabs of the electrode current collectors provided on each of the plurality of electrodes are gathered together and welded, The above concave portion is an electrode assembly positioned at the welding portion of the electrode tab.

23. In claim 21, The above concave portion is formed in the first metal layer, It further includes an additional metal layer laminated on the outer surface of the first metal layer, An electrode assembly wherein the additional metal layer is positioned on the electrode tab.

24. In claim 21, The above concave part A first concave portion formed in the first metal layer; and a second concave portion formed in the second metal layer, An electrode assembly in which the first concave portion and the second concave portion are formed to face each other in the stacking direction.

25. A method for manufacturing an electrode collector, A lamination process for forming a laminate by laminating a first metal layer and a second metal layer on both sides of a polymer layer; A tab forming process for forming an electrode tab by notching an end portion of the above laminate; and A method for manufacturing an electrode current collector, comprising a concave portion forming process of forming a concave portion toward the polymer layer in at least one of the first metal layer or the second metal layer in the electrode tab.

26. In claim 25, The above concave formation process is A first pressing step of forming a first concave portion by pressing a part of the first metal layer using a pressing means; and A method for manufacturing an electrode current collector, comprising a second pressing step of pressing a portion of the second metal layer using a pressing means to form a second concave portion.

27. In claim 26, The above concave formation process is A method for manufacturing an electrode current collector, wherein the first pressurizing step and the second pressurizing step are performed simultaneously, and the first concave portion and the second concave portion are formed to face each other at positions spaced apart from each other by a certain distance.

28. In claim 27, The above concave portion forming process includes a pressing step of pressing a portion of the first metal layer toward the polymer layer using a pressing means to form the concave portion. A method for manufacturing an electrode current collector, further comprising an additional lamination process of further laminating an additional metal layer on the outer surface of the first metal layer after the above-mentioned concave portion forming process.

29. In claim 28, The above pressurizing step A method for manufacturing an electrode current collector, wherein the concave portion is formed so that the concave portion and the second metal layer are positioned at a constant distance from each other.

30. In claim 28, The above lamination process is formed by depositing the first metal layer and the second metal layer on both sides of the polymer layer, The above additional lamination process is a method for manufacturing an electrode current collector by laminating the additional metal layer with the first metal layer by applying heat and pressure.

31. In claim 28, The above lamination process is formed by depositing the first metal layer and the second metal layer on both sides of the polymer layer, The above additional lamination process is a method for manufacturing an electrode current collector by depositing the additional metal layer on the outer surface of the first metal layer.

32. In claim 28, The above additional lamination process is a method for manufacturing an electrode current collector by laminating the additional metal layer so that it is positioned on the electrode tab.

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