Electrode assembly, secondary battery comprising electrode assembly, and electrode assembly manufacturing method

Abstract

The present invention relates to an electrode assembly, a secondary battery comprising the electrode assembly, and an electrode assembly manufacturing method. The electrode assembly according to the present invention comprises: an electrode stack formed from a plurality of alternately stacked electrodes and separators; and electrode leads electrically connected to the electrode stack, wherein: the electrode includes an electrode current collector including an electrode tab that extends from an end portion thereof; the electrode current collector includes a polymer layer and metal layers, each stacked on one of two surfaces of the polymer layer in the stacking direction; the electrode tabs of the electrode current collectors respectively provided in the plurality of electrodes form tab stacks that are gathered together, and further include metal clips that surround end portions of the tab stacks; and the electrode leads are connected to one-side portions of the metal clips so as to be electrically connected to the electrode stack.

Description

Electrode assembly, secondary battery including electrode assembly, and method for manufacturing electrode assembly

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0107661, filed August 17, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

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

[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 assembly with improved weldability, a secondary battery including the electrode assembly, and a method for manufacturing the electrode assembly.

[0009] An electrode assembly according to an embodiment of the present invention comprises: an electrode stack in which a plurality of electrodes and separators are alternately stacked; and an electrode lead electrically connected to the electrode stack, wherein the electrode includes an electrode current collector including an electrode tab extending from an end thereof, and the electrode current collector includes a polymer layer and a metal layer stacked on each of both sides of the polymer layer in a stacking direction, wherein the electrode tabs of the electrode current collectors provided on each of the plurality of electrodes form a tab stack that is gathered together, and further comprises a metal clip that surrounds an end of the tab stack, and wherein the electrode lead can be electrically connected to the electrode stack by being connected to one side of the metal clip.

[0010] In addition, a secondary battery according to an embodiment of the present invention includes an electrode assembly and a battery case accommodating the electrode assembly, the electrode assembly including an electrode laminate in which a plurality of electrodes and separators are alternately laminated; and an electrode lead electrically connected to the electrode laminate, the electrode including an electrode current collector including an electrode tab extending from an end thereof, the electrode current collector including a polymer layer and a metal layer laminated on each side of the polymer layer in a lamination direction, the electrode tabs of the electrode current collectors respectively provided on the plurality of electrodes form a tab laminate that is gathered together, and further includes a metal clip wrapping an end of the tab laminate, and the electrode lead can be electrically connected to the electrode laminate by being connected to one side of the metal clip.

[0011] In addition, a method for manufacturing an electrode assembly according to an embodiment of the present invention may include a lamination step of laminating a metal layer on both sides of a polymer layer to form a current collector laminate; and a tab forming step of notching an end portion of the laminate to form an electrode tab, thereby forming an electrode current collector; an electrode laminate forming step of alternately laminating a plurality of electrodes and separators including the electrode current collector to form an electrode laminate; a tab gathering step of gathering electrode tabs of the electrode current collectors respectively provided on the plurality of electrodes to form a tab laminate; a lead connecting step of connecting an electrode lead to one surface of a metal sheet; and a folding step of folding an end portion of the tab laminate so that the other surface of the metal sheet wraps around it to form a metal clip.

[0012] According to the present invention, since the electrode tabs of an electrode current collector having a metal layer laminated on both sides of a polymer layer are gathered together at the end of a tab laminate body with a metal clip wrapped around them, and the electrode lead is connected to the metal clip, there is an effect of significantly improving the weldability of the electrode tab and the electrode lead.

[0013] Figure 1 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention.

[0014] Fig. 2 is a cross-sectional view showing a main part of an electrode assembly according to an embodiment of the present invention.

[0015] Figure 3 is a perspective view showing an electrode collector in an electrode assembly according to an embodiment of the present invention.

[0016] Fig. 4 is a cross-sectional view showing an electrode laminate in an electrode assembly according to an embodiment of the present invention.

[0017] FIG. 5 is a cross-sectional view showing a first example of an electrode current collector in an electrode assembly according to an embodiment of the present invention.

[0018] Fig. 6 is a cross-sectional view showing a second example of an electrode current collector according to an embodiment of the present invention.

[0019] Fig. 7 is a cross-sectional view showing a third example of an electrode current collector according to an embodiment of the present invention.

[0020] Figure 8 is a cross-sectional view showing a secondary battery including an electrode assembly according to an embodiment of the present invention.

[0021] Figure 9 is a perspective view showing a lamination process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0022] Figure 10 is a perspective view showing a tab forming process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0023] Fig. 11 is a cross-sectional view showing a tab assembly step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0024] Fig. 12 is a cross-sectional view showing a lead connection step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0025] Fig. 13 is a cross-sectional view showing a mounting step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0026] Fig. 14 is a cross-sectional view showing a folding step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0027] FIG. 15 is a cross-sectional view showing an example of a stamping step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0028] Fig. 16 is a cross-sectional view showing another example of a stamping step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0029] 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.

[0030]

[0031] Electrode assembly according to the embodiment

[0032]

[0033] FIG. 1 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a main part of an electrode assembly according to an embodiment of the present invention, and FIG. 3 is a perspective view showing an electrode current collector in an electrode assembly according to an embodiment of the present invention.

[0034] Referring to FIGS. 1 to 3, an electrode assembly (10) according to an embodiment of the present invention includes an electrode stack (100) in which a plurality of electrodes (130) and separators (140) are alternately stacked, and an electrode lead (200) electrically connected to the electrode stack (100), wherein the electrode (130) includes an electrode current collector (110) including an electrode tab (111) extended at an end, and the electrode current collector (110) includes a polymer layer (112) and a metal layer (115) stacked on each side of the polymer layer (112) in a stacking direction (D), and the electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) form a tab stack (T) that is gathered together, and further includes a metal clip (300) that wraps around an end of the tab stack (T), and the electrode lead (200) is connected to one side of the metal clip (300) to thereby connect the electrode It is electrically connected to the laminate (100).

[0035]

[0036] Fig. 4 is a cross-sectional view showing an electrode laminate in an electrode assembly according to an embodiment of the present invention.

[0037] In more detail, referring to FIGS. 1 and 4, the electrode stack (100) is a power plant capable of charging and discharging, in which a plurality of electrodes (130) and separators (140) are alternately stacked.

[0038] The electrode (130) includes an electrode current collector (110) including an electrode tab (111) extending from one end.

[0039] 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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).

[0045] 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 (D).

[0046] 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.

[0047]

[0048] Referring to FIG. 3, 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).

[0049] In addition, the electrode current collector (110) includes a polymer layer (112) and a metal layer (115) laminated on both sides of the polymer layer (112) in the lamination direction (D). At this time, the metal layer (115) includes a first metal layer (113) laminated on one side of the polymer layer (112) and a second metal layer (114) laminated on the other side (F2).

[0050] Here, the polymer layer (112) is a layer containing a polymer material, and the metal layer (115) is a layer containing 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), so that fire caused by excessive current density that occurs when the electrode current collector is made of only a metal material can be prevented. In addition, the electrode current collector (110) can have the first metal layer (113) and the second metal layer (114) formed thinly on both sides, so that when breaking occurs, the risk of short circuit due to a metal burr or the like can be reduced.

[0051] Additionally, the polymer layer (112) may be formed of a material including, for example, PET (polyethylene terephthalate), PI (polyimide), or EN (polyethylenenaphthalate).

[0052] Meanwhile, the thickness of the first metal layer (113) may be, for example, the same as the thickness of the second metal layer (114).

[0053] Meanwhile, the electrode current collector (110) may be composed of a body (117) on the outer surface of which an electrode active material is coated and an electrode tab (111) extending from the body (117).

[0054] Meanwhile, referring to FIGS. 1 and 2, the electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) can form a tab stack (T) that is gathered together.

[0055] At this time, the tab laminate (T) may be in a form in which the ends of the electrode tabs (111) are gathered together and welded.

[0056]

[0057] Referring to FIGS. 1 and 2, the electrode lead (200) is electrically connected to the electrode stack (100) so that the electrode stack (100) can be electrically connected to an external device.

[0058] The end of the electrode lead (200) can be fixed by welding to the outer surface of the metal clip (300). At this time, a welded portion (P) can be formed by welding between the electrode lead (200) and the metal clip (300).

[0059]

[0060] The metal clip (300) can wrap around the end of the tab stack (T). At this time, the electrode stack (100) and the electrode lead (200) can be electrically connected by connecting one side of the metal clip (300) and the electrode lead (200).

[0061] The metal clip (300) is provided in a form in which both sides (301, 303) are bent relative to the central part (302), and the both sides (301, 303) of the metal clip (300) can each contact the metal layer (115) of the electrode current collector (110) located on the outermost sides in the stacking direction (D) of the tab stack (T).

[0062] Here, the metal clip (300) can be provided in a folded form in the shape of a “ㄷ”.

[0063] At this time, one side of the metal clip (300) and the electrode lead (200) can be connected.

[0064] Meanwhile, the metal clip (300) and the metal layer (115) of the electrode current collector (110) may include the same metal material.

[0065]

[0066] FIG. 5 is a cross-sectional view showing a first example of an electrode current collector in an electrode assembly according to an embodiment of the present invention, FIG. 6 is a cross-sectional view showing a second example of an electrode current collector according to an embodiment of the present invention, and FIG. 7 is a cross-sectional view showing a third example of an electrode current collector according to an embodiment of the present invention.

[0067] Referring to FIGS. 2 and 5 to 7, a protrusion (116) protruding toward a metal clip (300) may be formed on the metal layer (115) of the electrode current collector (110) located at the outermost side of the tab stack (T). Accordingly, the electrical contact between the metal layer (115) and the metal clip (300) may be increased.

[0068] The protrusions (116) may be formed in the form of a plurality of dots or lines along the surface facing the metal clip (300) in the metal layer (115). Here, the protrusions (116) may be formed in the form of a plurality of circular dots or in the form of a plurality of parallel lines provided at regular intervals.

[0069] Specifically, referring to FIG. 5, the protrusions (116) may be formed in the form of a plurality of circular dots as a first example. In this case, the protrusions (116) in the form of circular dots may be arranged in a plurality of columns and rows along the outer surface of the metal layer (115).

[0070] In addition, referring to FIG. 6, the protrusions (116') may be formed in the form of parallel lines arranged at regular intervals in multiple rows as a second example. In this case, the protrusions (116') may be formed along the outer surface of the metal layer (115) located on the electrode tab (111') of the electrode current collector (110').

[0071] In addition, referring to FIG. 7, the protrusions (116") may be formed in the form of parallel lines arranged in a plurality of rows at regular intervals as a third example. In this case, the protrusions (116") may be formed along the outer surface of the metal layer (115) located on the electrode tab (111") of the electrode current collector (110").

[0072]

[0073] Referring to FIGS. 1 and 2, the electrode assembly (10) according to the embodiment of the present invention configured as described above has an end of a tab laminate (T) in which electrode tabs (111) of an electrode current collector (110) having a metal layer (115) laminated on both sides of a polymer layer (112) are gathered together, and a metal clip (300) surrounds the end of the tab laminate (T), and an electrode lead (200) is connected to the metal clip (300), so that the weldability of the electrode tab (111) and the electrode lead (200) is significantly improved.

[0074]

[0075] Secondary battery according to the embodiment

[0076]

[0077] Below, a secondary battery according to an embodiment of the invention will be described.

[0078] Figure 8 is a cross-sectional view showing a secondary battery including an electrode assembly according to an embodiment of the present invention.

[0079] Referring to FIGS. 1 to 3 and 8, a secondary battery (1) according to an embodiment of the present invention includes an electrode assembly (10) and a battery case (20) accommodating the electrode assembly (10), the electrode assembly (10) includes an electrode stack (100) in which a plurality of electrodes (130) and separators (140) are alternately stacked, and an electrode lead (200) electrically connected to the electrode stack (100), the electrode (130) includes an electrode current collector (110) including an electrode tab (111) extended to an end, the electrode current collector (110) includes a polymer layer (112) and a metal layer (115) stacked on both sides of the polymer layer (112) in a stacking direction (D), and the electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) form a tab stack (T) that is gathered together, and the end of the tab stack (T) It further includes a wrapping metal clip (300), and the electrode lead (200) is electrically connected to the electrode laminate (100) by being connected to one side of the metal clip (300).

[0080] A secondary battery (1) according to an embodiment of the present invention relates to a secondary battery (1) including an electrode assembly (10) according to the embodiment described above. Therefore, in this embodiment, any content overlapping with the embodiment described above will be omitted or briefly described.

[0081]

[0082] In more detail, the battery case (20) has a receiving portion formed therein for receiving the electrode assembly (10). Here, the battery case (20) receives the electrode laminate (100), and the electrode lead (200) has one side positioned inside the battery case (20) and connected to the electrode laminate (100), and the other side can extend to the outside of the battery case (20).

[0083] The electrode stack (100) is a power plant capable of charging and discharging, and a plurality of electrodes (130) and separators (140) are alternately stacked.

[0084] The electrode (130) includes an electrode current collector (110) including an electrode tab (111) extending from one end.

[0085] The electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) can form a tab stack (T) that is gathered together.

[0086] The metal clip (300) can wrap around the end of the tab stack (T). At this time, the electrode stack (100) and the electrode lead (200) can be electrically connected by connecting one side of the metal clip (300) and the electrode lead (200).

[0087] The metal clip (300) is provided in a form in which both sides (301, 303) are bent relative to the central part (302), and the both sides (301, 303) of the metal clip (300) can each contact the metal layer (115) of the electrode current collector (110) located on the outermost sides in the stacking direction (D) of the tab stack (T).

[0088]

[0089] Method for manufacturing an electrode assembly according to an embodiment

[0090]

[0091] Hereinafter, a method for manufacturing an electrode assembly according to an embodiment of the present invention will be described.

[0092] FIG. 9 is a perspective view showing a lamination process in a method for manufacturing an electrode assembly according to an embodiment of the present invention, and FIG. 10 is a perspective view showing a tab forming process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0093] Referring to FIGS. 1, 2, 9, and 10, a method for manufacturing an electrode assembly according to an embodiment of the present invention includes a lamination process for forming a current collector laminate (S) by laminating a metal layer (115) on both sides of a polymer layer (112), and a tab forming process for forming electrode tabs (111) by notching the end portions of the current collector laminate (S), a current collector forming step for forming an electrode current collector (110), an electrode laminate forming step for alternately laminating a plurality of electrodes (130) and separators (140) including the electrode current collector (110) to form an electrode laminate (100), a tab gathering step for gathering the electrode tabs (111) of the electrode current collectors (110) provided on each of the plurality of electrodes (130) to form a tab laminate (T), a lead connecting step for connecting an electrode lead (200) to one side (F1) of a metal sheet (300'), and a tab It includes a folding step of forming a metal clip (300) by folding the end of the laminate (T) so that the other side (F2) of the metal sheet (300') wraps around it. In addition, the method for manufacturing an electrode assembly according to an embodiment of the present invention may further include a mounting step, a stamping step, and a protrusion forming step.

[0094] The method for manufacturing an electrode assembly according to an embodiment of the present invention relates to a method for manufacturing an electrode assembly (10) according to the embodiment of the present invention described above and an electrode assembly (10) included in a secondary battery according to an embodiment of the present invention.

[0095] Accordingly, in the embodiment of the electrode assembly manufacturing method according to the 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.

[0096]

[0097] In more detail, the entire body formation step includes a lamination process and a tab formation process.

[0098] Referring to Fig. 9, the lamination process forms a current collector laminate (S) by laminating a metal layer (115) on both sides of a polymer layer (112).

[0099] The lamination process can form a metal layer (115) by depositing metal on both sides of the polymer layer (112) in the lamination direction (D).

[0100] The lamination process can be performed by laminating a first metal layer (113) on one side of a polymer layer (112) in the lamination direction (D) and laminating a second metal layer (114) on the other side (F2).

[0101] Here, the polymer layer (112) is a layer containing a polymer material, and the metal layer (115) is a layer containing a metal material.

[0102]

[0103] Referring to Fig. 10, the tab forming process forms an electrode tab (111) by notching the end portion of the laminate.

[0104] That is, the tab forming process can form an electrode tab (111) in a protruding shape by cutting one side of a current collector 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).

[0105] Additionally, the tab forming process can be performed by notching the electrode tab (111) in the current collector stack (S) using a punch die or laser.

[0106]

[0107] Referring to FIG. 4, the electrode laminate formation step alternately laminates a plurality of electrodes (130) including an electrode current collector (110) and a separator (140) to form an electrode laminate (100).

[0108] At this time, the electrode laminate formation step may alternately laminate the positive electrode, the separator (140), and the negative electrode. Here, the electrode laminate formation step may position the separator (140) at the outermost layer in the lamination direction (D).

[0109]

[0110] Fig. 11 is a cross-sectional view showing a tab assembly step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0111] Referring to FIG. 11, the tab assembly step gathers the electrode tabs (111) of the electrode current collectors (110) provided on each of a plurality of electrodes (130) together to form a tab stack (T).

[0112] That is, the tab assembly step can form a tab laminate (T) by pressing and welding the ends of electrode tabs (111) extending from the electrode current collector (110) of the electrode (130) together to bring them together.

[0113]

[0114] Fig. 12 is a cross-sectional view showing a lead connection step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0115] Referring to Fig. 12, the lead connection step connects the electrode lead (200) to one side (F1) of the metal sheet (300').

[0116] The lead connection step can be performed by welding the electrode lead (200) to the metal sheet (300').

[0117]

[0118] Fig. 13 is a cross-sectional view showing a mounting step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0119] Referring to Fig. 13, the settling step can set the tab laminate (T) on the first part (F21) on the other side (F2) of the metal sheet (300') after the lead connection step.

[0120]

[0121] Referring to FIG. 13, the protrusion forming step can form a protrusion (116) protruding toward a metal clip (300) on the metal layer (115) of the electrode current collector (110) located at the outermost edge of the tab laminate (T) in the stacking direction (D) before the folding step.

[0122] The protrusion formation step can form a plurality of protrusions (116) in the form of dots or lines on the metal layer (115) along the surface facing the metal clip (300).

[0123] For example, the protrusion formation step can form a protrusion (116) by depositing metal on a surface of a metal layer (115) facing a metal clip (300).

[0124] As another example, the protrusion formation step can form a protrusion (116) by positioning a metal strip in the form of a dot or line between a metal layer (115) and a metal sheet (300').

[0125]

[0126] Fig. 14 is a cross-sectional view showing a folding step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0127] Referring to Fig. 14, the folding step forms a metal clip (300) by folding the end of the tab laminate (T) so that the other side (F2) of the metal sheet (300') wraps around it.

[0128] Additionally, the folding step may surround the end of the electrode tab (111) with the second portion (F22) on the other side (F2) of the metal sheet (300') after the settling step.

[0129] In addition, the folding step can be performed so that the length (L) of the part of the second part (F22) of the folded metal sheet (300') facing the upper surface of the tab laminate (T) is 5 to 50 mm.

[0130] In the second part (F22) of the metal sheet (300'), the length (L) of the part facing the upper surface of the tab laminate (T) is formed to be 5 mm or more, which is the lower limit, so that electrical contact is effectively possible, and the upper limit is formed to be 50 mm or less, so that folding of the metal sheet (300') can be easy.

[0131] And, the folding step can be performed so that both sides of the metal sheet (300') are in contact with the metal layer (115) of the electrode current collector (110) located on the outermost sides in the stacking direction (D) of the tab stack (T).

[0132]

[0133] Meanwhile, the method for manufacturing an electrode assembly according to an embodiment of the present invention may further include a fixing step of fixing the metal layer (115) of the electrode current collector (110) and both sides of the metal sheet (300') by welding them after the folding step.

[0134]

[0135] FIG. 15 is a cross-sectional view showing an example of a stamping step in a method for manufacturing an electrode assembly according to an embodiment of the present invention, and FIG. 16 is a cross-sectional view showing another example of a stamping step in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0136] Referring to FIGS. 15 and 16, the stamping step may be performed after the folding step by stamping the outermost two sides of the tab laminate (T) in the stacking direction (D), thereby fixing the metal clip (300) to the tab laminate (T).

[0137]

[0138] Here, the stamping step can be performed by pressing both sides (301, 303) of the metal clip (300) in the stacking direction from both sides through a stamping means (E), thereby fixing the metal clip (300) to the tab stack (T).

[0139] Meanwhile, referring to FIG. 15, the stamping step can be formed, for example, so that both sides (301, 303) of the metal clip (300) are parallel to the outermost surface of the tab laminate (T).

[0140] And, referring to FIG. 16, the stamping step can form convex portions (301a, 302b) in the direction of the tab laminate (T) on both sides (301, 303) of the metal clip (300) as another example.

[0141]

[0142] 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.

[0143] Additionally, the specific scope of protection of the invention will be made clear by the appended claims.

[0144]

[0145] [Explanation of symbols]

[0146] 1: Secondary battery

[0147] 10: Electrode assembly

[0148] 20: Battery case

[0149] 100: Electrode stack

[0150] 110, 110', 110": Electrode current collector

[0151] 110a: positive current collector

[0152] 110b: Negative current collector

[0153] 111, 111', 111": Electrode tab

[0154] 112: Polymer layer

[0155] 113: First metal layer

[0156] 114: Second metal layer

[0157] 115: Metal layer

[0158] 116, 116', 116": protrusions

[0159] 117: Body

[0160] 120: Electrode active material

[0161] 120a: Positive electrode active material

[0162] 120b: Negative active material

[0163] 130: Electrode

[0164] 130a: positive pole

[0165] 130b: cathode

[0166] 140: Membrane

[0167] 200: Electrode lead

[0168] 300: Metal Clip

[0169] 300': Metal sheet

[0170] D: Stacking direction

[0171] E: Stamping means

[0172] P: Welding

[0173] S: Whole-house stack

[0174] T: Tab laminate

Claims

1. An electrode laminate in which a plurality of electrodes and separators are alternately laminated; and an electrode lead electrically connected to the electrode laminate, The above electrode comprises an electrode collector including an electrode tab extending from one end thereof, The above electrode current collector includes a polymer layer and a metal layer laminated on each side of the polymer layer in the lamination direction, The electrode tabs of the electrode current collectors provided on each of the plurality of electrodes form a tab laminate that is gathered together, Further comprising a metal clip wrapping around the end of the above tab laminate, An electrode assembly in which the electrode lead is electrically connected to the electrode laminate through being connected to one side of the metal clip.

2. In claim 1, An electrode assembly in which a protrusion is formed toward the metal clip on the metal layer of the electrode current collector located at the outermost side of the tab laminate.

3. In claim 2, The above protrusion An electrode assembly formed in the shape of a plurality of dots or lines along a surface facing the metal clip on the metal layer.

4. In claim 3, The above protrusion An electrode assembly formed in the form of a plurality of circular dots or a plurality of parallel lines arranged at regular intervals.

5. In claim 1, An electrode assembly in which the metal layer of the electrode current collector and the metal clip include the same metal material.

6. In claim 1, The above metal clip is an electrode assembly provided in a folded form in the shape of a “ㄷ”.

7. In claim 1, The above metal clip is provided in a form in which both sides are bent relative to the central portion, An electrode assembly in which both sides of the above metal clip are each in contact with the metal layer of the electrode current collector located on the outermost both sides in the stacking direction of the above tab stack.

8. Including an electrode assembly and a battery case accommodating the electrode assembly, The electrode assembly comprises an electrode laminate in which a plurality of electrodes and separators are alternately laminated; and an electrode lead electrically connected to the electrode laminate. The above electrode comprises an electrode collector including an electrode tab extending from one end thereof, The above electrode current collector includes a polymer layer and a metal layer laminated on each side of the polymer layer in the lamination direction, The electrode tabs of the electrode current collectors provided on each of the plurality of electrodes form a tab laminate that is gathered together, Further comprising a metal clip wrapping around the end of the above tab laminate, A secondary battery in which the electrode lead is electrically connected to the electrode laminate through being connected to one side of the metal clip.

9. A current collector forming step for forming an electrode current collector, including a lamination process for laminating a metal layer on both sides of a polymer layer to form a current collector laminate; and a tab forming process for forming an electrode tab by notching an end portion of the current collector laminate; An electrode laminate forming step of forming an electrode laminate by alternately laminating a plurality of electrodes and a separator including the above electrode collector; A tab assembly step of forming a tab laminate by bringing together the electrode tabs of the electrode current collectors provided on each of the plurality of electrodes; A lead connection step for connecting an electrode lead to one side of a metal sheet; and A method for manufacturing an electrode assembly, comprising a folding step of forming a metal clip by folding an end portion of the above tab laminate so that the other side of the metal sheet wraps around it.

10. In claim 9, The above lead connection step connects the electrode lead by welding it to the metal sheet, After the above lead connecting step, a mounting step is further included for mounting the tab laminate on the first part of the other side of the metal sheet, The above folding step is a method for manufacturing an electrode assembly in which the end of the electrode tab is surrounded by a second part on the other side of the metal sheet after the above fixing step.

11. In claim 10, After the above folding step, A method for manufacturing an electrode assembly further comprising a stamping step of stamping both sides of the metal clip located on the outermost two surfaces of the tab laminate in the lamination direction to secure the metal clip to the tab laminate.

12. In claim 10, Before the above folding step, A method for manufacturing an electrode assembly further comprising a protrusion forming step of forming a protrusion that protrudes toward the metal clip on the metal layer of the electrode current collector located at the outermost edge of the tab laminate in the lamination direction.

13. In claim 12, The above protrusion forming step is a method for manufacturing an electrode assembly in which the protrusions are formed in the form of a plurality of dots or lines on the metal layer along a surface facing the metal clip.

14. In claim 12, The above lamination process forms the metal layer by depositing metal on both sides of the polymer layer in the lamination direction. The above protrusion forming step is a method for manufacturing an electrode assembly in which a metal is deposited on a surface of the metal layer facing the metal clip to form the protrusion.

15. In claim 12, A method for manufacturing an electrode assembly, wherein the protrusion is formed by positioning a metal strip in the shape of a dot or line between the metal layer and the metal sheet in the protrusion formation step, and then the folding step is performed.

16. In claim 10, The above folding step is A method for manufacturing an electrode assembly, wherein the length of a portion of the second part of the metal sheet being folded, which faces the upper surface of the tab laminate, is 5 to 50 mm.

17. In claim 9, The above folding step is A method for manufacturing an electrode assembly in which both sides of the metal sheet are folded so that they each contact the metal layers of the electrode current collectors located on the outermost sides in the lamination direction of the tab laminate.

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