Method for manufacturing secondary battery

Abstract

There is provided a secondary battery manufacturing method including the steps of: laminating a plurality of unit cells in a first direction to form a laminated electrode assembly; coupling a multifunction terminal block (MTB) to both ends of the stacked electrode assembly extending in the second direction; attaching a laminated sheet to the multi-function terminal block to surround the laminated electrode assembly; injecting an electrolyte into the laminated electrode assembly; and sealing the laminated sheet to form a cell housing, wherein the multifunctional terminal block comprises: a multifunctional terminal block housing; a bus bar disposed within the multifunctional terminal block case and electrically connected to the laminated electrode assembly; and an electrode terminal portion exposed to the outside of the multifunctional terminal block case and electrically connected to the bus bar.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a secondary battery, and more specifically, to a method for manufacturing a secondary battery capable of producing high-capacity secondary batteries without concern for damage or defects in the battery pouch.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0127695, filed on September 25, 2023, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as power sources for various wireless devices, including mobile phones, laptops, and cordless vacuum cleaners. In recent years, due to increased energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased significantly, and the driving range of battery electric vehicles (BEVs) has reached levels comparable to that of gasoline-powered vehicles. Therefore, the primary application area for secondary batteries has shifted from mobile devices to the transportation sector.

[0004] At the same time, the demand for high-capacity battery packs used in electric vehicles is increasing. High-capacity battery packs in automobiles need to improve safety while increasing capacity. Summary of the Invention

[0005] Technical issues

[0006] The technical problem of this disclosure is to provide a method for manufacturing a secondary battery that can produce high-capacity secondary batteries without worrying about damage or defects in the battery pouch.

[0007] Technical solution

[0008] To address the aforementioned technical problems, this disclosure provides a method for manufacturing a secondary battery. The method includes: stacking a plurality of cell units along a first direction to form a stacked electrode assembly; connecting a multi-functional terminal block (MTB) to both ends of the stacked electrode assembly extending along a second direction; attaching a laminate to the MTB to surround the stacked electrode assembly; injecting an electrolyte into the stacked electrode assembly; and sealing the laminate to form a cell housing. The multi-functional terminal block includes: a multi-functional terminal block housing; a busbar disposed within the multi-functional terminal block housing and electrically connected to the stacked electrode assembly; and an electrode terminal portion exposed outside the multi-functional terminal block housing and electrically connected to the busbar.

[0009] In some embodiments, the stacked electrode assembly may include: a first electrode stack comprising a plurality of cell units stacked along the first direction and sharing an electrode lead; and a second electrode stack comprising a plurality of cell units stacked along the first direction and sharing another electrode lead.

[0010] In some implementations, the electrode leads connected to the first electrode stack and the electrode leads connected to the second electrode stack can be connected to a single busbar.

[0011] In some embodiments, the stacked electrode assembly has three or more electrode stacks, wherein the thickness of the stacked electrode assembly along the first direction may be greater than the thickness of the multifunctional terminal block housing along the first direction.

[0012] In some embodiments, during the step of attaching the laminate to the multifunctional terminal block, the laminate may be an unformed flat laminate.

[0013] In some embodiments, the laminate may include: a flexible metal layer; an inner resin layer disposed on one side of the metal layer; and an outer resin layer disposed on the other side of the metal layer.

[0014] In some embodiments, attaching the laminate to the multifunctional terminal block may include fusing the inner resin layer to the outside of the multifunctional terminal block housing.

[0015] In some implementations, the electrolyte injection step can be performed after the laminate is attached to the multifunctional terminal block.

[0016] In some embodiments, during the step of attaching the laminate to the multifunctional terminal block, a pair of parallel edges of the laminate are fused to the side of the multifunctional terminal block housing, and the pair of parallel ends of the laminate may include portions that are not fused to each other.

[0017] In some embodiments, the electrolyte can be injected through the portion of a pair of parallel ends of the laminate that are not fused together.

[0018] In some embodiments, the step of sealing the laminate may include fusing the inner resin layers at the pair of parallel ends together.

[0019] In some embodiments, the multi-functional terminal block housing may include: an inner shell that houses the busbar; and an outer shell that houses the inner shell and defines the appearance of the multi-functional terminal block housing.

[0020] In some embodiments, the housing comprises a metallic material, and the electrode terminals may be electrically insulated from the housing.

[0021] Another aspect of this disclosure provides a secondary battery comprising: a stacked electrode assembly including a plurality of cell cells stacked along a first direction and having electrode leads at both ends along a second direction perpendicular to the first direction; a multifunctional terminal block disposed at both ends of the stacked electrode assembly; and a laminate surrounding the sides of the stacked electrode assembly, wherein the thickness of the stacked electrode assembly along the first direction is greater than the thickness of the multifunctional terminal block along the first direction.

[0022] In some embodiments, the multi-functional terminal block may include: a busbar electrically connected to the stacked electrode assembly; an inner housing housing the busbar; an outer housing housing the inner housing and defining the appearance of the multi-functional terminal block; and an electrode terminal portion exposed to the outside of the outer housing and electrically connected to the busbar.

[0023] Beneficial effects

[0024] The manufacturing method disclosed herein has the effect of being able to manufacture high-capacity secondary batteries without causing damage or defects to the bag.

[0025] The effects obtainable from the exemplary embodiments of this disclosure are not limited to those described above, and other effects not mentioned can be clearly derived and understood by those skilled in the art from the following description. In other words, those skilled in the art can also obtain unintended effects from practicing the exemplary embodiments of this disclosure. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0027] Figures 2 to 9 This is a schematic diagram illustrating a method for manufacturing a secondary battery according to one embodiment of the present disclosure.

[0028] Figure 10 This is a side view showing a secondary battery according to one embodiment of the present disclosure.

[0029] Figure 11 This is an exploded perspective view of a multifunctional terminal block of a secondary battery according to one embodiment of the present disclosure. Detailed Implementation

[0030] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, embodiments of the present disclosure may be varied in many other forms and should not be construed as limiting the scope of the disclosure to the following embodiments. Preferably, embodiments of the present disclosure are provided to provide a more comprehensive explanation of the present disclosure to those skilled in the art. The same names generally refer to the same elements. Furthermore, various elements and areas in the drawings are depicted schematically. Therefore, the present disclosure is not limited to the relative dimensions or spacing depicted in the drawings.

[0031] Terms such as "first" and "second" may be used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish one component from another. For example, without departing from the scope of the concept of this disclosure, a first component may be named a second component, and vice versa.

[0032] The terminology used in this application is for describing certain embodiments only and is not intended to limit the concept of this disclosure. Unless the context clearly indicates otherwise, singular expressions include plural meanings. In this application, expressions such as “comprising” or “having” are intended to indicate the presence of the described features, quantities, steps, operations, components, parts, or combinations thereof, and should not be construed as excluding the possibility of the presence or addition of one or more other features, quantities, operations, components, parts, or combinations thereof.

[0033] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the concepts of this disclosure pertain. It should also be understood that these terms (e.g., commonly used terms and terms defined in dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of their relevant field, and shall not be interpreted in an overly formal sense unless expressly defined herein.

[0034] When implementation methods can be instantiated differently, the execution order of certain processes may differ from the described order. For example, two consecutively described processes may be executed substantially simultaneously, or in the reverse order of their description.

[0035] In the accompanying drawings, for example, the geometries shown may deviate due to manufacturing techniques and / or tolerances. Therefore, embodiments of this disclosure should not be construed as limited to specific geometries of the areas shown herein, and should include variations in geometry, such as those caused by manufacturing processes. All terms “and / or” as used herein include any and every combination of one or more components mentioned. Furthermore, as used herein, the term “substrate” may refer to the substrate itself, or to a laminated structure comprising the substrate and any predetermined layers or films formed on its surface. Additionally, as used herein, the term “surface of the substrate” may refer to the exposed surface of the substrate itself, or to the outer surface of a predetermined layer or film formed on the substrate.

[0036] (First Implementation)

[0037] Figure 1 This is a flowchart illustrating a secondary battery manufacturing method 100 according to one embodiment of the present disclosure. Figures 2 to 9 This is a schematic diagram illustrating a secondary battery manufacturing method 100 according to one embodiment of the present disclosure.

[0038] In the following figures, the secondary battery 100 is shown as being defined in a vertical coordinate system, which is defined by a first direction perpendicular to each other along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis, but the first direction, the second direction, and the third direction only need to be perpendicular to each other, and there are no particular restrictions.

[0039] Reference Figure 1 and Figure 2 Multiple cell units 111 can be stacked along a first direction (e.g., the X-axis direction) to form a stacked electrode assembly 110 (S110).

[0040] Each of the multiple cell 111 can be an electrode material applied to a metal foil that acts as a current collector.

[0041] Each cell 111 may have a thin plate-like body extending along a second direction (e.g., the Y-axis direction). Each cell 111 may be a positive cell or a negative cell. In some embodiments, a plurality of cells 111 may be an alternating stack of a positive cell and a negative cell. The positive cell and the negative cell may be separated from each other by a separator.

[0042] In some other embodiments, the plurality of cell units 111 may be a plurality of positive electrode cell units and a plurality of negative electrode cell units stacked alternately. The plurality of positive electrode cell units and the plurality of negative electrode cell units may be separated from each other by a separator.

[0043] The stacked electrode assembly 110 may have electrode tabs 113 at both ends along a second direction (e.g., the Y-axis direction). In some embodiments, the electrode tabs 113 may be extensions of the metal foil portion of the unit cell 111. In some embodiments, the electrode tabs 113 may be electrically connected to the metal foil portion of the unit cell 111.

[0044] In some embodiments, the electrode tabs 113 located on the same side of the cell 111 may have the same polarity.

[0045] Figure 3 This is a schematic diagram of electrode leads 116 formed on electrode tabs 113 located on one side of the cell 111.

[0046] Reference Figure 3 Multiple electrode tabs 113 can be electrically connected to a single electrode lead 116. Electrode leads 116 can be electrically connected to electrode tabs 113 of multiple cell units 111. One electrode lead 116 can be connected to one or more electrode tabs 113. In some embodiments, two or more electrode tabs can be connected to one electrode lead 116.

[0047] In some embodiments, the plurality of electrode tabs 113 may first be joined together, for example by soldering, and then connected to the electrode lead 116. In other embodiments, the plurality of electrode tabs 113 may be connected to each other and simultaneously electrically connected to the electrode lead 116.

[0048] The stacked electrode assembly 110 may include a first electrode stack 110a that is stacked along a first direction (e.g., the X-axis direction) and shares an electrode lead 116, and a second electrode stack 110b that is stacked along a first direction (e.g., the X-axis direction) and shares another electrode lead 116.

[0049] In some embodiments, the stacked electrode assembly 110 may have two electrode leads 116 on one side and two electrode leads 116 on the other side. In this case, the first electrode stack 110a included in the stacked electrode assembly 110 may have a first electrode lead 116a on one side (see...). Figure 4 ), and has a second electrode lead 116b on the other side (see Figure 4 Furthermore, the second electrode stack 110b included in the stacked electrode assembly 110 may have a third electrode lead 116c on one side (see...). Figure 4 ), and on the other side has a fourth electrode lead 116d (see Figure 4 However, this disclosure is not limited thereto.

[0050] In some embodiments, the stacked electrode assembly 110 may have one, three, or more electrode leads on one side. In some embodiments, the stacked electrode assembly 110 may have one, three, or more electrode leads on the other side.

[0051] Reference Figure 1 and Figure 4 The multi-function terminal block (MTB) 120 can be connected to both ends of the stacked electrode assembly 110 extending along a second direction (e.g., the Y-axis direction) (S120).

[0052] The first multi-functional terminal block 120a may be disposed at one end of the stacked electrode assembly 110 along a second direction (e.g., along the Y-axis direction), and the second multi-functional terminal block 120b may be disposed at the other end. One of the first multi-functional terminal block 120a and the second multi-functional terminal block 120b may be electrically connected to the positive electrode side of the stacked electrode assembly 110, and the other may be electrically connected to the negative electrode side of the stacked electrode assembly 110.

[0053] In the electrode leads 116 of the first electrode stack 110a, the first electrode lead 116a can be connected to the first multi-function terminal block 120a, and the second electrode lead 116b can be connected to the second multi-function terminal block 120b. In the electrode leads 116 of the second electrode stack 110b, the third electrode lead 116c can be connected to the first multi-function terminal block 120a, and the fourth electrode lead 116d can be connected to the second multi-function terminal block 120b.

[0054] The second multi-function terminal block 120b may have substantially the same configuration as the first multi-function terminal block 120a, differing only in polarity. The first multi-function terminal block 120a will be described below, but those skilled in the art will be able to recognize the configuration of the second multi-function terminal block 120b from this description.

[0055] The first multi-functional terminal block 120a may include a multi-functional terminal block housing 122, an electrode terminal portion 124 housed within the multi-functional terminal block housing 122, and a bus bar 125 electrically connecting the electrode terminal portion 124 and the electrode lead 116 (see Figure 5 ).

[0056] The multi-functional terminal block housing 122 may be made of a material with high hardness, such as metal, and defines the exterior of the first multi-functional terminal block 120a. In some embodiments, the multi-functional terminal block housing 122 may be made of aluminum (Al), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), or an alloy containing one or more of the aforementioned materials.

[0057] The multi-functional terminal block housing 122 may include a through-hole exposing the electrode terminal portion 124, as described below. The through-hole may be provided in the multi-functional terminal block housing 122 such that the electrode terminal portion 124 is exposed in a second direction (e.g., the Y-axis direction). Therefore, the through-hole may be provided in a plane perpendicular to the second direction (e.g., the Y-axis direction) of the multi-functional terminal block housing 122. Furthermore, the through-hole may have an opening that opens along the longitudinal direction of the electrode assembly 110. The shape of the through-hole may be configured to conform to the outer peripheral shape of the portion of the electrode terminal portion 124 exposed to the outside.

[0058] Those skilled in the art will understand that, as described below, the first multi-functional terminal block 120a may further include, as needed, a through-hole for an exhaust plate, a through-hole for a check valve, etc.

[0059] The electrode terminal portion 124 is housed within the multifunctional terminal block housing 122 and can be exposed through a through-hole. The electrode terminal portion 124 can be made of a metal or metal alloy with low resistance, such as copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), platinum (Pt), manganese (Mn), or an alloy containing one or more of the aforementioned materials.

[0060] In some embodiments, the exposed surface of the electrode terminal portion 124 exposed outward from the multifunctional terminal block housing 122 may be a plane. In some embodiments, the exposed surface may have a plane extending perpendicular to a second direction (e.g., the Y-axis direction).

[0061] In some embodiments, an electrical insulating spacer may be disposed between the electrode terminal portion 124 and the multifunctional terminal block housing 122, so that the electrode terminal portion 124 is electrically insulated from the multifunctional terminal block housing 122.

[0062] In some embodiments, the first multi-functional terminal block 120a may include a rupture disc 126 configured to rupture in the event of an excessive increase in internal pressure of the secondary battery 100, thereby releasing the gas causing the excessive increase in internal pressure. If the rupture disc 126 ruptures due to a thermal event occurring inside the secondary battery 100, the rupture disc 126 may not be able to return to its initial state. The rupture disc 126 may be any rupture disc known in the art and is not particularly limited thereto.

[0063] In some embodiments, the first multi-function terminal block 120a may further include a check valve 128. The check valve 128 may be configured to open to release gas within the secondary battery 100 when the internal pressure of the secondary battery 100 becomes higher than a predetermined pressure, and to close again when the internal pressure is released by the gas release. After the internal gas is released, the check valve 128 can return to its initial state because there is no part of the check valve 128 that was ruptured due to the gas release.

[0064] An additional busbar can be installed within the first multi-functional terminal block 120a. Figure 5 This is a schematic diagram showing a cross-section of the first multi-functional terminal block 120a cut through the electrode terminal portion 124 and in a plane perpendicular to a third direction (e.g., the Z-axis direction).

[0065] Reference Figure 5 The busbar 125 may be configured to make surface contact with the electrode terminal portion 124. The busbar 125 may be made of a metal material with low resistance. In some embodiments, the busbar 125 may be made of copper (Cu), nickel (Ni), aluminum (Al), iron (Fe), cobalt (Co), platinum (Pt), molybdenum (Mo), tin (Sn), palladium (Pd), or an alloy comprising one or more of the aforementioned materials.

[0066] Busbar 125 can be configured to make surface contact with electrode leads 116 of the stacked electrode assembly 110. In some embodiments, busbar 125 can be soldered to electrode leads 116. In some embodiments, busbar 125 can be fastened to electrode leads 116 using fasteners such as rivets.

[0067] Reference Figure 4 and Figure 5 The first electrode lead 116a of the first electrode stack 110a and the third electrode lead 116c of the second electrode stack 110b can be connected to a single busbar 125. In the same manner, the second electrode lead 116b of the first electrode stack 110a and the fourth electrode lead 116d of the second electrode stack 110b can be connected to a busbar 125 disposed within the second multi-function terminal block 120b.

[0068] In some embodiments, the busbar 125 may include a planar central portion 125c extending horizontally along a first direction (e.g., the X-axis direction) and an edge portion 125e that curves and extends from the central portion 125c. In some embodiments, the central portion 125c may be configured to form a generally U-shaped cross-sectional shape together with the edge portion 125e, and may extend along a third direction (e.g., the Z-axis direction). In some embodiments, the edge portion 125e may have a plane extending perpendicular to the first direction (e.g., the X-axis direction).

[0069] The busbar 125 can make surface contact with the electrode terminal portion 124 at its center portion 125c. The busbar 125 can make surface contact with the electrode lead 116 at its edge portion 125e.

[0070] In some embodiments, the electrode lead 116 may include a pre-bent portion that bends at the portion that does not contact the busbar 125. The pre-bent portion can prevent stress from concentrating in specific areas of the electrode lead 116 due to external forces applied to the stacked electrode assembly 110, thereby improving safety.

[0071] Reference Figure 1 and Figure 6 The laminate 130 can be attached to the multifunctional terminal block 120 to surround the stacked electrode assembly 110.

[0072] Laminate 130 may be an unshaped, flat laminate. As used herein, referring to laminate 130 as flat means only that it is not pre-shaped to at least partially accommodate the stacked electrode assembly 110, and does not mean that laminate 130 is free of curvature.

[0073] Figure 7 This is a partial cross-sectional view of a laminate 130 according to one embodiment of the present disclosure.

[0074] Reference Figure 1 , Figure 6 and Figure 7 The laminate 130 can be configured to wrap around the side surface of the stacked electrode assembly 110. In some embodiments, the laminate 130 can be attached to the side surface of the multifunction terminal block 120 such that it at least partially covers the side surface of the multifunction terminal block 120. In some embodiments, the laminate 130 can cover the entire side surface of the multifunction terminal block 120 in a second direction (e.g., the Y-axis direction). In some other embodiments, the laminate 130 can cover only the portion of the side surface of the multifunction terminal block 120 parallel to the second direction (e.g., the Y-axis direction).

[0075] The laminate 130 may include a flexible metal layer 134, an inner resin layer 132 disposed on one side of the metal layer 134, and an outer resin layer 136 disposed on the other side of the metal layer 134.

[0076] The metal layer 134 can maintain a suitable thickness to prevent water vapor, oxygen, and other gases from permeating from the outside into the inside, and to prevent electrolyte leakage. In some embodiments, the metal layer 134 may be one or more of iron (Fe), carbon (C), chromium (Cr), manganese (Mn), nickel (Ni), aluminum (Al), and their alloys. The metal layer 134 may be made of an iron-containing material to provide greater mechanical strength, or of an aluminum material to provide greater flexibility, and aluminum foil is typically used.

[0077] The metal layer 134 can be configured to have a suitable thickness and mechanical strength, making it easier to deform by externally applied forces and not to produce cracks or holes during repeated deformation.

[0078] In some embodiments, the metal layer 134 may have a thickness of about 20 micrometers (μm) to about 100 μm. In some embodiments, the thickness of the metal layer 134 may be about 20 micrometers (μm) to about 100 μm, about 25 μm to about 95 μm, about 30 μm to about 90 μm, about 35 μm to about 85 μm, about 40 μm to about 80 μm, about 45 μm to about 75 μm, about 50 μm to about 70 μm, about 55 μm to about 60 μm, or fall within any two of these values.

[0079] An inner resin layer 132 disposed on one side of the metal layer 134 may include a heat-bonding layer. In some embodiments, the inner resin layer 132 may include a polyolefin-based material capable of achieving a sealing effect through melting. In some embodiments, the inner resin layer 132 may include modified propylene, such as non-stretch cast polypropylene (CPP) or a polypropylene-butene-ethylene terpolymer.

[0080] The inner resin layer 132 can be formed by coating or laminating one side of the metal layer 134.

[0081] An outer resin layer 136 disposed on the other side of the metal layer 134 can serve as a substrate and protective layer for forming the laminate 130. The outer resin layer 136 may include an insulating material, such as polyethylene terephthalate (PET) or nylon.

[0082] In some embodiments, the inner resin layer 132 and the outer resin layer 136 may each have a thickness of about 10 micrometers (μm) to about 50 μm. In some embodiments, the respective thickness ranges of the inner resin layer 132 and the outer resin layer 136 may be about 10 micrometers (μm) to about 50 μm, about 12 μm to about 48 μm, about 15 μm to about 45 μm, about 17 μm to about 43 μm, about 20 μm to about 40 μm, about 22 μm to about 38 μm, about 25 μm to about 35 μm, about 27 μm to about 33 μm, or fall within any two of these values.

[0083] In some embodiments, the adhesive resin layer may also be disposed between the inner resin layer 132 and the metal layer 134 and / or between the outer resin layer 136 and the metal layer 134. The adhesive resin layer can be used for smooth attachment between different materials. The adhesive resin layer can be formed as a single layer or multiple layers. In some embodiments, the adhesive resin layer may include polyolefin-based resin, polyurethane-based resin, epoxy-based resin, or mixtures thereof.

[0084] In some embodiments, the inner resin layer 132 may be fused at both ends in a second direction (e.g., the Y-axis direction) to a fused resin layer 122p disposed on the side of the multifunctional terminal block 120. When the laminate 130 surrounds the side of the multifunctional terminal block 120, the inner resin layer 132 may be fused to the fused resin layer 122p, so that the stacked electrode assembly 110 can be encapsulated within the secondary battery. The inner resin layer 132 may be fused to the side by heating and melting, and then cooling, while in contact with the fused resin layer 122p on the side of the multifunctional terminal block 120.

[0085] The fused resin layer 122p is a thermoplastic resin layer and may include at least one of, for example, polyolefin-based resin, polyester-based resin, polyamide-based resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylonitrile, polyurethane, polycarbonate, polyacetal, polyacrylate, and modified polyvinyl alcohol resin.

[0086] Polyolefin-based resins include, for example, polyethylene, polypropylene, poly(1-butene), poly(4-methyl-1-pentene), ethylene-propylene copolymers, copolymers of ethylene with α-olefins having 4 or more carbon atoms, polyolefin-maleic anhydride copolymers, ethylene-vinyl ester copolymers, ethylene-acrylate copolymers, or modified polyolefins grafted with unsaturated carboxylic acids or their derivatives, but this disclosure is not limited thereto.

[0087] Polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate, but this disclosure is not limited thereto.

[0088] Polyamide-based resins include nylon 6, nylon 66, nylon 6 / 66 copolymer, nylon 11, nylon 12 or poly(m-phenylene adipamide), but this disclosure is not limited thereto.

[0089] The fused resin layer 122p can be prepared by casting, or by uniaxial stretching, biaxial stretching or calendering.

[0090] In some embodiments, the fusion resin layer 122p may at least partially cover one side of the multifunctional terminal block housing 122. In some embodiments, the fusion resin layer 122p may extend from the inner end of the side of the multifunctional terminal block housing 122 toward the outer end of the side of the multifunctional terminal block housing 122. In some embodiments, the fusion resin layer 122p may surround the side of the multifunctional terminal block housing 122 having a predetermined width between the inner and outer ends.

[0091] Figure 8 This is a perspective view showing the laminate 130 fused to the side of the multi-functional terminal block 120.

[0092] Reference Figure 7 and Figure 8 The laminate 130 may have a pair of substantially parallel edges 130e fused to the outside of the multifunctional terminal block 120. Meanwhile, the pair of substantially parallel ends 130t connecting the pair of edges 130e of the laminate 130 may not be fused to each other, and a portion of the stacked electrode assembly 110 may be exposed between the pair of ends 130t.

[0093] Although a pair of end 130t in Figure 8 The figure shows that they are not completely fused together in the longitudinal direction, but the pair of ends 130t can be substantially fused in the longitudinal direction, and are not fused only on a portion of their length.

[0094] Reference Figure 1 and Figure 8 Electrolyte can be supplied to the stacked electrode assembly 110 (S140) through a pair of unfused portions at the ends 130t.

[0095] In some embodiments, the step of providing electrolyte may be performed after the laminate 130 is attached to the multifunctional terminal block 120. In some embodiments, the step of providing electrolyte may be performed after sealing the laminate. In this case, at least one multifunctional terminal block 120 may include an electrolyte inlet.

[0096] The electrolyte can be any conventional electrolyte used in lithium secondary batteries and is not particularly limited thereto.

[0097] Reference Figure 1 and Figure 9 The laminate 130 can be sealed to form a cell housing 130c (S150). The cell housing 130c can define the internal space of the secondary battery 100 together with the multi-functional terminal block 120.

[0098] To seal the laminate 130, the ends 130t of the laminate 130 can be fused together to form a joint 130m. The joint 130m can be formed by fusion welding between the inner resin layers 132 of the laminate 130. Specifically, the inner resin layer 132 of one end 130t and the inner resin layer 132 of the other end 130t can be fused together to form the joint 130m. In some embodiments, the welding can be thermal welding, but this disclosure is not limited thereto.

[0099] According to reference Figures 1 to 9 The described secondary battery manufacturing method 100 allows for the manufacture of a secondary battery 100 containing multiple electrode stacks because the laminate 130 is not subjected to a forming process. If a forming process is performed on the laminate to manufacture a secondary battery containing multiple electrode stacks, the laminate may be damaged at the step portions and defects may increase due to the additional steps required. On the other hand, referring to… Figures 1 to 9 The described secondary battery manufacturing method 100 does not require the forming process of the laminate 130, so even when multiple electrode stacks are accommodated, large-capacity cells can be achieved without worrying about damage to the laminate and the resulting defects.

[0100] (Second Implementation)

[0101] Figure 10 This is a side view showing a secondary battery 100 according to one embodiment of the present disclosure.

[0102] Reference Figure 10 The thickness of the stacked electrode assembly 110 along a first direction (e.g., the X-axis direction) can be greater than the thickness of the multifunctional terminal block housing 122 along the first direction (e.g., the X-axis direction). The stacked electrode assembly 110 may include two, three, four, or more electrode stacks, thereby proportionally increasing the thickness along the first direction (e.g., the X-axis direction). The large thickness of the stacked electrode assembly 110 allows it to be surrounded by the laminate 130 without the need for a forming process, thus avoiding damage to the laminate 130 and the potential for defects therefrom.

[0103] (Third implementation method)

[0104] Figure 11 This is an exploded perspective view showing a multifunctional terminal block 120 of a secondary battery 100 according to one embodiment of the present disclosure.

[0105] Reference Figure 11 The multi-function terminal block 120 may include an inner shell 122b that houses the busbar 125 and an outer shell 122a that houses the inner shell 122b and defines the exterior of the multi-function terminal block housing 122.

[0106] In some embodiments, the inner shell 122b may be made of an insulator. In some embodiments, the inner shell 122b may be made of a polymeric resin. In some embodiments, the inner shell 122b may be formed by injection molding. The inner shell 122b may include a through-hole through which the electrode terminal portion 124 can pass.

[0107] In some embodiments, the housing 122a may include a metallic material. In some embodiments, the housing 122a may include a metal such as aluminum, and may be made, for example, of aluminum or an aluminum alloy.

[0108] For reference Figure 4 and Figure 5 The housing 122a may have a through hole through which the electrode terminal portion 124 can pass. In some embodiments, the housing 122a may have a through hole for providing a rupture disc 126, a check valve 128, etc., and the rupture disc 126, the check valve 128, etc. may be disposed in these through holes.

[0109] The housing 122a can be made of an electrical conductor, in which case an insulating washer 129 can be provided to electrically insulate it from the electrode terminal portion 124. The insulating washer 129 can be provided along the inner peripheral surface of the through hole through which the electrode terminal portion 124 passes.

[0110] The electrode terminal portion 124 can be configured to make surface contact with the center portion 125c of the busbar 125. The electrode terminal portion 124 can be exposed to the outside of the multi-functional terminal block 120 while making surface contact with the busbar 125 by penetrating the inner shell 122b and the outer shell 122a.

[0111] Although embodiments of the present disclosure have been described in detail above, many modifications will be possible to this disclosure by those skilled in the art without departing from the spirit and scope of the disclosure as defined by the appended claims. Therefore, subsequent modifications to embodiments of the present disclosure will not depart from the technical spirit of the disclosure.

[0112] Explanation of reference numerals in the attached figures

[0113] 100: Secondary battery

[0114] 110: Stacked electrode assembly

[0115] 110a: First electrode stack

[0116] 110b: Second electrode stack

[0117] 111: Cell Unit

[0118] 113: Electrode tabs

[0119] 116: Electrode leads

[0120] 120: Multifunctional Terminal Block

[0121] 122: Multifunctional Terminal Block Housing

[0122] 122a: Outer shell

[0123] 122b: Inner shell

[0124] 122p: Fusion resin layer

[0125] 124: Electrode terminal section

[0126] 125: Busbar

[0127] 126: Ruptured disc

[0128] 128: Check valve

[0129] 129: Insulating Washer

[0130] 130: Laminated sheets

Claims

1. A method for manufacturing a secondary battery, the method comprising: Multiple unit cells are stacked along a first direction to form a stacked electrode assembly; The multi-functional terminal block MTB is connected to both ends of the stacked electrode assembly extending along the second direction; A laminate is attached to the multifunctional terminal block to surround the stacked electrode assembly; Electrolyte is injected into the stacked electrode assembly; as well as The laminates are sealed to form a cell housing, wherein: The multi-functional terminal block includes: Multifunctional terminal block housing; Busbar, the busbar being disposed within the multi-functional terminal block housing and electrically connected to the stacked electrode assembly; and The electrode terminal portion is exposed outside the housing of the multifunctional terminal block and is electrically connected to the busbar.

2. The method for manufacturing a secondary battery according to claim 1, wherein: The stacked electrode assembly includes: A first electrode stack, the first electrode stack comprising a plurality of unit cells stacked along the first direction and sharing an electrode lead; and The second electrode stack includes multiple cell units stacked along the first direction and sharing another electrode lead.

3. The method for manufacturing a secondary battery according to claim 2, wherein: Electrode leads connected to the first electrode stack and electrode leads connected to the second electrode stack are connected to a single busbar.

4. The method for manufacturing a secondary battery according to claim 2, wherein: The stacked electrode assembly has three or more electrode layers, wherein the thickness of the stacked electrode assembly along the first direction is greater than the thickness of the multifunctional terminal block housing along the first direction.

5. The method for manufacturing a secondary battery according to claim 1, wherein: In the step of attaching the laminate to the multifunctional terminal block, the laminate is a flat laminate that has not undergone forming.

6. The method for manufacturing a secondary battery according to claim 1, wherein: The laminate comprises: A flexible metal layer; An inner resin layer, the inner resin layer being disposed on one side of the metal layer; and An outer resin layer is disposed on the other side of the metal layer.

7. The method for manufacturing a secondary battery according to claim 6, wherein: Attaching the laminate to the multifunctional terminal block includes fusing the inner resin layer to the outside of the multifunctional terminal block housing.

8. The method for manufacturing a secondary battery according to claim 6, wherein: The electrolyte injection step is performed after the laminate is attached to the multifunctional terminal block.

9. The method for manufacturing a secondary battery according to claim 8, wherein: In the step of attaching the laminate to the multifunctional terminal block, a pair of parallel edges of the laminate are fused to the side of the multifunctional terminal block housing, and the pair of parallel ends of the laminate include portions that are not fused to each other.

10. The method for manufacturing a secondary battery according to claim 9, wherein: The injection of the electrolyte is performed through the portion of a pair of parallel ends of the laminate that are not fused together.

11. The method for manufacturing a secondary battery according to claim 9, wherein: The step of sealing the laminate includes fusing the inner resin layers at the pair of parallel ends together.

12. The method for manufacturing a secondary battery according to claim 1, wherein: The multi-functional terminal block housing includes: Inner shell, the inner shell accommodating the busbar; and The housing contains the inner housing and defines the appearance of the multifunctional terminal block housing.

13. The method for manufacturing a secondary battery according to claim 12, wherein: The outer casing comprises a metal material, and The electrode terminal portion is electrically insulated from the outer casing.

14. A secondary battery, the secondary battery comprising: A stacked electrode assembly, the stacked electrode assembly comprising a plurality of unit cells stacked along a first direction, and having electrode leads at both ends along a second direction perpendicular to the first direction; A multi-functional terminal block (MTB) is disposed at both ends of the stacked electrode assembly; as well as A laminate surrounding the sides of the stacked electrode assembly, wherein: The thickness of the stacked electrode assembly along the first direction is greater than the thickness of the multifunctional terminal block along the first direction.

15. The secondary battery according to claim 14, wherein: The multi-functional terminal block includes: A busbar, the busbar being electrically connected to the stacked electrode assembly; Inner shell, the inner shell accommodating the busbar; A housing that accommodates the inner housing and defines the appearance of the multi-functional terminal block; and The electrode terminal portion is exposed to the outside of the housing and is electrically connected to the busbar.

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