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

Abstract

The present invention relates to an electrode assembly. The electrode assembly according to an aspect of the present invention may comprise: a stack part in which electrodes and separators are alternately interposed and which has a first side and a second side perpendicular to the first side; electrode tabs which are connected to the electrodes and protrude outward from the first side of the stack part through a gap between the separators; openings provided on the second side of the stack part so that gas between the separators can flow to the outside therethrough; and a fixing member which fixes the electrodes and the separators and covers at least some of the openings.

Description

Electrode assembly, secondary battery including same, and manufacturing method thereof

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0188301, filed December 21, 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 same, and a method for manufacturing the same, and more specifically, to an electrode assembly in which electrodes and separators are alternately arranged, a secondary battery including the same, and a method for manufacturing the same.

[0005] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used not only in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in larger products requiring high output, such as electric and hybrid vehicles, as well as in power storage devices that store surplus power or renewable energy, and as backup power storage devices.

[0006] To manufacture these secondary batteries, electrodes are first manufactured by applying an electrode active material slurry to a current collector, which is then laminated on both sides of a separator to form an electrode assembly of a predetermined shape. The electrode assembly is then housed in a battery case, filled with an electrolyte, and sealed. The battery case may be a pouch.

[0007] Meanwhile, electrode assemblies are classified into various types. For example, there is the Simple Stack Type, which simply alternately stacks anodes, separators, and cathodes; the Lamination & Stack Type (L&S), which first manufactures electrode cells using unit electrodes and separators and then stacks these electrode cells; the Stack & Folding Type (S&F), which spaces apart and attaches a plurality of unit electrodes or electrode cells to one side of a long separator sheet and repeatedly folds the separator sheet in the same direction from one end; and the Z-Folding Type, which alternately attaches a plurality of electrodes or electrode cells to one side and the other side of a long separator sheet and alternately folds the separator sheet in a specific direction from one end and then in the opposite direction.

[0008] However, the electrode assembly manufactured by the folding method has a problem in that the folded portion of the separator sheet is blocked, making it difficult for gas between the separators to be smoothly discharged through the folded portion. On the other hand, the electrode assembly manufactured by the stack method has no portion blocked in the circumferential direction because the separator sheet is cut into unit lengths. Therefore, the stacked electrode assembly can relatively smoothly discharge gas between the separators. However, because the separator sheet is cut, there is a problem in that the positions of the stacked electrodes and separators are relatively less fixed than in the folding method.

[0009] Accordingly, there has been an urgent need for the development of an electrode assembly in which alternately stacked electrodes and separators can be stably fixed while allowing gas between the separators to be smoothly discharged in various directions, a secondary battery including the same, and a manufacturing method thereof.

[0010] The present invention has been devised to solve the above problems, and the object of the present invention is to provide an electrode assembly having a stable structure while allowing gas between separators to be smoothly discharged to the outside, a secondary battery including the same, and a method for manufacturing the same.

[0011] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0012] According to one aspect of the present invention, an electrode assembly is provided, comprising: a laminated portion having electrodes and separators alternately disposed therebetween, the laminated portion having a first side and a second side perpendicular to the first side; an electrode tab connected to the electrode and protruding outwardly between the separators at the first side of the laminated portion; an opening provided at the second side of the laminated portion so that gas between the separators can flow to the outside; and a fixing member fixing the electrode and the separator and covering at least a portion of the opening.

[0013] At this time, the fixing member may include a first fixing part attached to one surface of the laminated portion; a second fixing part attached to the other surface of the laminated portion; and a connecting part connecting the first fixing part and the second fixing part and covering at least a portion of the open portion.

[0014] At this time, the opening may extend in the longitudinal direction of the laminated portion, and the fixing member may be provided along the longitudinal direction of the laminated portion.

[0015] At this time, the connecting portion may be made of a porous material so that gas can pass between the separators.

[0016] At this time, a communication hole communicating with the opening portion may be formed in the connecting portion.

[0017] At this time, the above-mentioned communication holes may be provided in multiple numbers.

[0018] At this time, the fixing member may have a ring shape surrounding the periphery of the laminated portion.

[0019] At this time, the above-mentioned fixing member may be composed of a plurality of pieces and arranged along a direction parallel to the second side of the laminated portion.

[0020] At this time, the plurality of fixing members may include a first fixing member and a second fixing member respectively adjacent to both ends of the laminated portion in a direction parallel to the second side.

[0021] At this time, the opening can be formed by cutting the separator from one end to the other in a direction parallel to the second side.

[0022] At this time, the openings may be provided on opposite sides of the laminated portion.

[0023] At this time, the fixing member may be made of tape.

[0024] According to another aspect of the present invention, a secondary battery is provided, comprising: a pouch having an accommodation space therein; and an electrode assembly disposed in the accommodation space, wherein the electrode assembly comprises: a laminated portion having electrodes and separators alternately interposed therebetween and having a first side and a second side perpendicular to the first side; an electrode tab connected to the electrode and protruding outwardly between the separators at the first side of the laminated portion; an opening provided at the second side of the laminated portion so that gas between the separators can flow to the outside; and a fixing member fixing the electrode and the separator and covering at least a portion of the open portion.

[0025] According to another aspect of the present invention, a method for manufacturing a secondary battery is provided, comprising: a step of manufacturing an electrode assembly; a step of accommodating the electrode assembly in a receiving space of a pouch; a step of discharging gas in the receiving space to one side of the pouch; and a step of sealing the pouch, wherein the step of manufacturing the electrode assembly comprises: a step of forming a laminate including a laminate having a first side and a second side perpendicular to the first side, electrode tabs connected to the electrodes and protruding outward from the first side of the laminate, and an opening provided in the second side of the laminate so that gas between the electrodes and the separator can flow outward; and a step of attaching a fixing member covering at least a portion of the opening to the laminate so as to fix the electrodes and the separator.

[0026] At this time, in the step of accommodating the electrode assembly in the receiving space, the opening of the electrode assembly may be arranged so as to face one side of the pouch.

[0027] At this time, the step of forming the laminate may include the step of folding the separator sheet along a direction parallel to the second side so that the electrodes and the separator are alternately interposed; and the step of forming the opening in the portion of the separator sheet folded along the second side.

[0028] At this time, in the step of folding the separator sheet, several parts of the separator sheet overlap each other in the lateral direction of the electrode and the folded part is formed, and in the step of forming the opening, the folded part can penetrate in the overlapping direction.

[0029] At this time, in the step of forming the opening, the folded portion of the separator sheet may be cut or a communication hole may be formed in the folded portion of the separator sheet.

[0030] At this time, in the step of forming the opening, the folded portion of the separator sheet can be cut from one end to the other in a direction parallel to the second side.

[0031] According to one aspect of the present invention, an electrode tab is provided on a first side of a laminated portion in which electrodes and separators are alternately interposed, and an opening through which gas can flow is provided on a second side perpendicular to the first side, wherein a fixing member is configured to fix a relative position between the electrodes and the separator.

[0032] Through this, the gas between the separators can be smoothly discharged to the outside through the opening, while the structural stability of the electrode assembly can be increased by the fixing member.

[0033] According to one aspect of the present invention, a communication hole is formed in a portion of a fixing member covering an opening, or the portion is made of a porous material, so that obstruction of gas flow by the fixing member can be minimized, and thus gas between the membranes can be discharged more smoothly to the outside through the opening.

[0034] According to one aspect of the present invention, the electrode assembly is placed in the receiving space of the pouch such that the opening faces the opening formed in the gas collection portion of the pouch, so that the gas of the receiving space and the electrode assembly can be discharged more effectively to the outside of the pouch.

[0035] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0036] FIG. 1 is a perspective view of an electrode assembly according to a first embodiment of the present invention viewed from above.

[0037] Figure 2 is a vertical cross-sectional view of an electrode assembly according to a first embodiment of the present invention.

[0038] Figure 3 is an enlarged view of a portion of Figure 2.

[0039] Figure 4 is a perspective view of an electrode assembly according to a second embodiment of the present invention viewed from above.

[0040] Figure 5 is a perspective view of an electrode assembly according to a third embodiment of the present invention viewed from above.

[0041] Figure 6 is a perspective view of an electrode assembly according to a fourth embodiment of the present invention viewed from above.

[0042] Figure 7 is a perspective view of an electrode assembly according to a fifth embodiment of the present invention viewed from above.

[0043] Figure 8 is a vertical cross-sectional view of an electrode assembly according to a fifth embodiment of the present invention.

[0044] Figure 9 is a perspective view of an electrode assembly according to a sixth embodiment of the present invention viewed from above.

[0045] Figure 10 is a perspective view of a secondary battery according to one embodiment of the present invention, viewed from above. Here, the electrode assembly housed within the pouch is indicated by a dotted line.

[0046] Figure 11 is a flowchart of a secondary battery manufacturing method according to one embodiment of the present invention.

[0047] Figure 12 is a flowchart detailing step S110 of Figure 11.

[0048] FIG. 13 and FIG. 14 are drawings for explaining steps S200 and S300 according to one embodiment of the present invention.

[0049] Preferred embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0050] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0051] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0052] Hereinafter, an electrode assembly according to a first embodiment of the present invention is described.

[0053] Fig. 1 is a perspective view of an electrode assembly according to a first embodiment of the present invention, viewed from above. Fig. 2 is a vertical cross-sectional view of an electrode assembly according to the first embodiment of the present invention. Fig. 3 is an enlarged view of a portion of Fig. 2.

[0054] FIGS. 1 to 3 disclose an electrode assembly (30) according to a first embodiment of the present invention. Referring to FIGS. 1 to 3, the electrode assembly (30) according to the first embodiment of the present invention may be an assembly capable of charging and discharging electrical energy. In the present embodiment, the electrode assembly (30) may include a laminate (40).

[0055] In this embodiment, the laminate (40) may include a laminate portion (42) in which electrodes (43) and separators (44) are alternately interposed. As an example, the laminate portion (42) may be manufactured in a stack manner in which electrodes (43) and separators (44) are sequentially laminated.

[0056] In the illustrated embodiment, five separators (44) are stacked in the vertical direction (Z-axis direction), and four electrodes (43) are configured to be interposed one at a time between each separator (44). However, the number of separators (44) and electrodes (43) may be changed as needed.

[0057] In this embodiment, the electrode (43) may be a square plate, sheet, or film in which an electrode active material is applied to a metal thin film. However, the shape of the electrode (43) may be appropriately modified as needed.

[0058] At this time, in the present embodiment, the metal sheet may be a sheet made of aluminum (Al) or copper (Cu), and the electrode active material may be lithium-cobalt oxide (LCO), lithium-manganese oxide (LMO), nickel-cobalt-manganese (NCM), nickel-cobalt-aluminum (NCA), lithium-iron phosphate (LFP), graphite (C), silicon (Si), etc., but the type of the metal sheet and the type of the electrode active material are not limited to those described above.

[0059] In this embodiment, the separator (44) can perform the function of ensuring the stability of the electrode assembly (30) by preventing the stacked electrodes (43) from touching each other. Such a separator (44) can be made of polyethylene, polypropylene, or the like, but the type of material forming the separator (44) is not limited to those described above.

[0060] Referring again to FIGS. 1 and 2, the laminate (40) of the electrode assembly (30) according to the first embodiment of the present invention may include an electrode tab (45). The electrode tab (45) may be a tab for electrically connecting the electrode (43) to an external power source or load.

[0061] For this purpose, the electrode tab (45) may have a plate, film, or sheet shape extending outward from the edge of the electrode (43). The electrode tab (45) may be made of the same material as the metal plate forming the electrode (43).

[0062] At this time, in the present embodiment, the electrode tab (45) may protrude outwardly through the separator (44) at the first side of the laminated portion (42). The first side of the laminated portion (42) may refer to sides provided at the front (positive direction of the X-axis) and the rear (negative direction of the X-axis) of the laminated portion (42), respectively. The first side of the laminated portion (42) may extend in the left-right direction (Y-axis direction).

[0063] As illustrated, in this embodiment, gas between the separation membranes (44) can be discharged forward (in the positive direction of the X-axis) and backward (in the negative direction of the X-axis) through the first side of the laminated portion (42).

[0064] This may be because, on the first side of the laminated portion (42), the edges of the separator (44) are not attached to each other, allowing gas to flow. This may be because the electrode tab (45) connected to the electrode (43) protrudes outward through the space between the separator (44) on the first side.

[0065] Referring to FIGS. 1 to 3, the laminate (40) of the electrode assembly (30) according to the first embodiment of the present invention may include an opening (46). The opening (46) may refer to an open portion through which gas between the separators (44) may flow and be discharged. That is, the opening (46) may be formed by separating the edges of the separators (44) from each other so that they are not attached to each other.

[0066] In the present embodiment, the opening (46) may be provided on the second side of the laminated portion (42). At this time, the second side of the laminated portion (42) may mean a side perpendicular to the first side described above. More specifically, the second side of the laminated portion (42) may mean a side provided on each of the left and right sides (Y-axis direction) of the laminated portion (42).

[0067] At this time, in the present embodiment, the second side of the laminated portion (42) may extend in the front-back direction (X-axis direction). And, the opening (46) may be provided along the direction in which the second side extends (X-axis direction) on the side of the laminated portion (42). In the present disclosure, the longitudinal direction of the laminated portion (42) may mean the direction in which the second side extends (X-axis direction).

[0068] Accordingly, in this embodiment, the gas between the separation membranes (44) can be entirely discharged in the left-right direction (Y-axis direction) from the second side of the stacked portion (42) through the opening (46).

[0069] Meanwhile, as previously described, in the present embodiment, since the separators (44) are not connected or attached to each other at the first and second sides of the laminated portion (42), the relative positions of the laminated electrodes (43) and separators (44) may not be stably fixed. In other words, the overall structural stability of the laminated body (40) may be lowered due to the open portion (46).

[0070] To solve this, the electrode assembly (30) according to the first embodiment of the present invention may include a fixing member (50). The fixing member (50) may be a member for stably fixing the relative position between the electrode (43) and the separator (44) of the laminate (40).

[0071] As an example, the fixing member (50) may be formed of a film or sheet-shaped tape having an adhesive material applied to one side, but the fixing member (50) is not particularly limited as long as it can fix the positions of the electrode (43) and the separator (44).

[0072] Referring to FIGS. 1 and 2, in the present embodiment, the fixing member (50) may include a first fixing portion (52). In the present embodiment, the first fixing portion (52) may be a portion for supporting and fixing the upper side (positive direction of the Z-axis) of the laminate (40).

[0073] At this time, in the present embodiment, the first fixing portion (52) may be attached to the upper surface of the laminated portion (42). And, the first fixing portion (52) may be provided along the edge portion adjacent to the second side on the upper surface of the laminated portion (42). In other words, the first fixing portion (52) may be provided along the longitudinal direction (X-axis direction) of the laminated portion (42). This may be to more stably support and fix the second side in which the open portion (46) is formed in the laminated portion (42).

[0074] Meanwhile, in the present embodiment, the fixing member (50) may include a second fixing portion (54). In the present embodiment, the second fixing portion (54) may be a portion for supporting and fixing the lower side (negative direction of the Z-axis) of the laminate (40).

[0075] At this time, in the present embodiment, the second fixing part (54) may be attached to the lower surface of the laminated part (42). And, the second fixing part (54) may be provided along the edge portion adjacent to the second side on the lower surface of the laminated part (42). In other words, the second fixing part (54) may be provided along the longitudinal direction (X-axis direction) of the laminated part (42). This may be to more stably support and fix the second side in which the open part (46) is formed in the laminated part (42).

[0076] Meanwhile, referring to FIGS. 1 to 3, in the present embodiment, the fixing member (50) may include a connecting portion (56). The connecting portion (56) may be a portion that connects the first fixing portion (52) and the second fixing portion (54) described above.

[0077] By means of this connecting member (56), the supporting force and fixing force by the first fixing member (52) and the supporting force and fixing force by the second fixing member (54) can be applied together to the laminate (40). Through this, the fixing member (50) can increase the structural stability of the laminate (40).

[0078] At this time, in the present embodiment, the connecting portion (56) can extend in a direction parallel to the second side (X-axis direction) in parallel with the first fixing portion (52) and the second fixing portion (54). As a result, the second side of the laminated portion (42) can be entirely fixed and supported by the fixing member (50).

[0079] Meanwhile, in the present embodiment, the connecting portion (56) may cover at least a portion or an area of ​​the opening portion (46). This may be because the first fixing portion (52) and the second fixing portion (54) are arranged with a distance in the vertical direction (Z-axis direction) with the opening portion (46) between them.

[0080] In this way, if the connecting portion (56) covers the opening portion (46), the flow of gas flowing through the opening portion (46) may be impeded. This may hinder the discharge of gas between the separation membranes (44).

[0081] To resolve this, a communication hole (57) may be formed in the connecting portion (56) of the electrode assembly (30) according to the first embodiment of the present invention. The communication hole (57) may be a hole for communicating the opening portion (46) with the outside.

[0082] As illustrated in FIGS. 1 and 3, the communication hole (57) can be configured to penetrate the connecting portion (56). Accordingly, the gas between the separation membranes (44) can be smoothly discharged to the outside through the opening (46) and the communication hole (57), while the structural stability of the laminate (40) can be secured.

[0083] At this time, in the present embodiment, the communication holes (57) may be configured in multiple numbers. In addition, the multiple communication holes (57) may be evenly distributed in the connecting portion (56). This may be to ensure that the flow of gas through the opening portion (46) is more smoothly achieved.

[0084] As described above, the electrode assembly (30) according to the first embodiment of the present invention has an opening (46) provided on the second side of the laminated portion (42), so that gas between the separators (44) can be smoothly discharged to the outside through the second side as well.

[0085] In addition, the electrode assembly (30) according to the first embodiment of the present invention can increase the overall structural stability of the electrode assembly (30) by having a fixing member (50) attached to the laminate (40) to fix the electrode (43) and the separator (44).

[0086] Furthermore, in the electrode assembly (30) according to the first embodiment of the present invention, since a communication hole (57) is provided in the connecting portion (56) of the fixing member (50), obstruction of gas discharge by the fixing member (50) can be minimized.

[0087] Meanwhile, referring back to FIG. 1, in the present embodiment, the fixing member (50) may be configured as a pair and may be provided on each of the left and right sides (Y-axis direction) of the laminated portion (42). Accordingly, the electrode (43) and separator (44) of the laminated body (40) may be supported and fixed more evenly. Of course, the fixing member (50) may be configured as a single unit, if necessary.

[0088] Hereinafter, an electrode assembly according to a second embodiment of the present invention will be described with different drawings.

[0089] Figure 4 is a perspective view of an electrode assembly according to a second embodiment of the present invention viewed from above.

[0090] Figure 4 discloses an electrode assembly (130) according to a second embodiment of the present invention. According to the electrode assembly (130) according to the second embodiment of the present invention, the connecting portion (156) of the fixing member (150) may be made of a porous material.

[0091] For example, the connecting portion (156) may be made of a material such as PET (Polyethylene terephthalate), PE (Polyethylene), PP (Polypropylene), CPP (Casting polypropylene), etc. However, the material of the connecting portion (156) is not particularly limited as long as the gas between the separators (44) can pass through it.

[0092] Through this, in the electrode assembly (130) according to the second embodiment of the present invention, the gas between the separators (44) can flow outward through the connecting portion (156) of the fixing member (150), so that the obstruction of the gas flow by the fixing member (150) can be minimized.

[0093] Therefore, the electrode assembly (130) according to the second embodiment of the present invention can ensure the structural stability of the laminate (40) while allowing the gas to be discharged smoothly through the opening (46).

[0094] Meanwhile, in the present embodiment, the connecting portion (156) of the fixing member (150) and the first fixing portion (52) and the second fixing portion are configured to be made of different materials. However, the first fixing portion (52) and the second fixing portion of the fixing member (150) may also be made of the same material as the connecting portion (156).

[0095] Hereinafter, an electrode assembly according to a third embodiment of the present invention will be described with different drawings.

[0096] Figure 5 is a perspective view of an electrode assembly according to a third embodiment of the present invention viewed from above.

[0097] Fig. 5 discloses an electrode assembly (230) according to a third embodiment of the present invention. The fixing member (250) of the electrode assembly (230) according to the third embodiment of the present invention may have a ring or band shape surrounding the periphery of the laminated portion (42). In this case, the periphery of the laminated portion (42) may be a portion surrounding the upper surface, lower surface, and second side of the laminated portion (42).

[0098] In this way, in the present embodiment, since the fixing member (250) is configured to entirely surround the laminated portion (42), the fixing force and support force by the fixing member (250) can be more strongly applied to the laminated body (40).

[0099] Meanwhile, in the present embodiment, when viewed in a direction parallel to the second side (X-axis direction), the length of the fixing member (250) may be shorter than the length of the second side of the laminated portion (42). This may be to minimize the portion covered by the fixing member (250) in the open portion (46).

[0100] At this time, in the present embodiment, the fixing member (250) may be configured in multiple pieces to supplement the fixing force and support force. In addition, the multiple fixing members (250) may be arranged in a direction parallel to the second side (X-axis direction).

[0101] Accordingly, a strong force can be applied to support or fix the laminate (40) by multiple fixing members (250). In addition, since the opening (46) located between the fixing members (250) is not blocked by the fixing members (250), gas can also be discharged smoothly through the opening (46).

[0102] Hereinafter, among the plurality of fixing members (250), the fixing member (250) located at the frontmost position (positive direction of the X-axis) is referred to as the first fixing member, and the fixing member (250) located at the rearmost position (negative direction of the X-axis) is referred to as the second fixing member.

[0103] At this time, in the present embodiment, the first fixing member and the second fixing member may be positioned adjacent to each end of the laminate (42) in a direction parallel to the second side (X-axis direction). This may be to allow the support force and fixing force of the fixing member (250) to be applied more effectively to the laminate (40).

[0104] Here, the fact that the fixing member (250) is positioned adjacent to the end of the laminated portion (42) may mean that the fixing member (250) is positioned closer to the end than to the central portion of the laminated portion (42).

[0105] Meanwhile, in the present embodiment, a communication hole (253) may be formed in a portion (252) covering the opening (46) of the fixing member (250). At this time, the communication hole (253) may be configured in the same manner as the communication hole (57) (illustrated in FIG. 1) described in the first embodiment. Through this, the obstruction of gas flow by the fixing member (250) may be minimized.

[0106] Hereinafter, an electrode assembly according to a fourth embodiment of the present invention will be described with different drawings.

[0107] Figure 6 is a perspective view of an electrode assembly according to a fourth embodiment of the present invention viewed from above.

[0108] FIG. 6 discloses an electrode assembly (330) according to a fourth embodiment of the present invention. Referring to FIG. 6, according to the electrode assembly (330) according to the fourth embodiment of the present invention, a portion (352) covering an opening (46) in a fixing member (350) may be made of a porous material. In this case, the porous material may be the same as the porous material described in the second embodiment.

[0109] Through this, in the electrode assembly (330) according to the fourth embodiment of the present invention, gas between the separators (44) can flow outward through the fixing member (350), so that obstruction of the gas flow by the fixing member (350) can be minimized.

[0110] Therefore, the electrode assembly (330) according to the fourth embodiment of the present invention can ensure the structural stability of the laminate (40) while allowing the gas to be discharged smoothly through the opening (46).

[0111] Meanwhile, in the present embodiment, the portion (352) covering the opening (46) of the fixing member (350) and the remaining portion are configured to be made of different materials. However, the fixing member (350) may also be made of the same material throughout.

[0112] Hereinafter, an electrode assembly according to a fifth embodiment of the present invention will be described with different drawings.

[0113] Fig. 7 is a perspective view of an electrode assembly according to a fifth embodiment of the present invention as viewed from above. Fig. 8 is a vertical cross-sectional view of an electrode assembly according to a fifth embodiment of the present invention.

[0114] FIGS. 7 and 8 disclose an electrode assembly (430) according to a fifth embodiment of the present invention. Referring to FIGS. 7 and 8, a laminate (140) of the electrode assembly (430) according to the fifth embodiment of the present invention can be formed by folding a single separator sheet multiple times in a direction parallel to the second side (X-axis direction).

[0115] In other words, the laminate (140) of the present electrode assembly (430) can be formed by folding a separator sheet that is elongated in a direction parallel to the first side (Y-axis direction) along a direction parallel to the second side (Y-axis direction) at a predetermined unit length. At this time, the unit length may correspond to the width of the electrode (43) or be longer than it. That is, the laminate (140) of the present electrode assembly (430) can be manufactured by a folding method.

[0116] Due to this, multiple parts of the separator sheet can be folded (or bent) on the second side of the laminated portion (142) to form an overlapping portion. Hereinafter, the portion is referred to as a folded portion (144a). As illustrated in FIG. 8, multiple separators can be overlapped on the folded portion (144a).

[0117] In this way, when the laminate (140) is manufactured in a folding manner, a folded portion (144a) is formed on the second side of the laminated portion (142), so it may be difficult for gas between the separators (144) to be discharged to the outside through the second side. This is because the folded portion (144a) is formed by overlapping multiple separators.

[0118] To resolve this, in the present embodiment, an opening (146) may be formed in the folded portion (144a). The opening (146) may be formed to penetrate the folded portion (144a) in the direction in which the separator sheets overlap (Y-axis direction). Through this, gas between the innermost separators (144) may directly escape to the outside through the opening (146).

[0119] Meanwhile, in the present embodiment, the opening (146) can be formed by cutting the folded portion (144a) in a direction parallel to the second side (X-axis direction). At this time, the opening (146) can be formed by cutting the folded portion (144a) from one end to the other in the above direction (X-axis direction).

[0120] Through this, the gas between the separation membranes (144) can be entirely discharged through the second side. Of course, the opening (146) can be formed by partially cutting the folded portion (144a) along the second side. Alternatively, the opening (146) can be provided in the form of a hole that penetrates the folded portion (144a) in the stacking direction (Y-axis direction).

[0121] Meanwhile, as described above, if an opening (146) is formed on the second side of the laminate (142), the separators (144) are separated from each other, so the relative position between the electrode (143) and the separator (144) may not be fixed. In other words, the structural stability of the laminate (140) may be lowered due to the opening (146).

[0122] To solve this, the electrode assembly (430) according to the fifth embodiment of the present invention may include a fixing member (450). The fixing member (450) may be a member for stably fixing the relative position between the electrode (143) and the separator (144) of the laminate (440).

[0123] As an example, the fixing member (450) may be formed of a film or sheet-shaped tape having an adhesive material applied to one side, but the fixing member (450) is not particularly limited as long as it can fix the positions of the electrode (143) and the separator (144).

[0124] Referring to FIG. 8, in the present embodiment, the fixing member (450) may include a first fixing portion (52), a second fixing portion (54), and a connecting portion (56). At this time, the first fixing portion (52), the second fixing portion (54), and the connecting portion (56) may be configured in the same manner as in the first embodiment. Through this, the structural stability of the laminate (140) may be increased.

[0125] Meanwhile, in the present embodiment, the connecting portion (56) may cover at least a portion or an area of ​​the opening portion (146). This may be because the first fixing portion (52) and the second fixing portion (54) are arranged with a distance in the vertical direction (Z-axis direction) with the opening portion (146) therebetween.

[0126] In this way, if the connecting portion (56) covers the opening portion (146), the flow of gas flowing through the opening portion (146) may be impeded. This may hinder the discharge of gas between the separation membranes (144).

[0127] To resolve this, a communication hole (457) may be formed in the connecting portion (56) of the electrode assembly (430) according to the fifth embodiment of the present invention. The communication hole (457) may be a hole for communicating the opening portion (146) with the outside.

[0128] As illustrated in FIGS. 7 and 8, the communication hole (457) may be configured to penetrate the connecting portion (56). Accordingly, the gas between the separators (144) can be smoothly discharged to the outside through the opening (146) and the communication hole (457), while the structural stability of the laminate (140) can be secured.

[0129] At this time, in the present embodiment, the communication holes (457) may be configured in multiple numbers. In addition, the multiple communication holes (457) may be arranged in a direction parallel to the second side. This may be to ensure a more smooth flow of gas through the opening (146).

[0130] As described above, the electrode assembly (430) according to the fifth embodiment of the present invention has an opening (146) along the second side of the folded portion (144a) of the laminated portion (142), so that gas between the separators (144) can be smoothly discharged to the outside through the folded portion (144a).

[0131] In addition, the electrode assembly (430) according to the fifth embodiment of the present invention has a fixing member (450) attached to the laminate (140) to fix the electrode (43) and the separator (44), so that the overall structural stability of the electrode assembly (430) can be increased.

[0132] Furthermore, in the electrode assembly (430) according to the fifth embodiment of the present invention, since a communication hole (457) is provided in the connecting portion (56) of the fixing member (450), obstruction of gas discharge by the fixing member (450) can be minimized.

[0133] Hereinafter, an electrode assembly according to a sixth embodiment of the present invention will be described with different drawings.

[0134] Figure 9 is a perspective view of an electrode assembly according to a sixth embodiment of the present invention viewed from above.

[0135] FIG. 9 discloses an electrode assembly (530) according to a sixth embodiment of the present invention. Referring to FIG. 9, the laminate (140) of the electrode assembly (530) according to the sixth embodiment of the present invention may be configured in the same manner as the fifth embodiment described above. That is, in the present embodiment, the laminate (140) may be manufactured in a folding manner, and an opening (146) may be formed in the folded portion (144a).

[0136] At this time, in the electrode assembly (530) according to the sixth embodiment of the present invention, the fixing member (550) may have a ring or band shape surrounding the periphery of the laminated portion (142). At this time, the periphery of the laminated portion (142) may be a portion surrounding the upper and lower surfaces of the laminated portion (142) and the folded portion (144a).

[0137] In this way, in the present embodiment, since the fixing member (550) is configured to entirely surround the laminated portion (142), the fixing force and support force by the fixing member (550) can be more strongly applied to the laminated body (140).

[0138] Meanwhile, in the present embodiment, when viewed in a direction parallel to the second side (X-axis direction), the length of the fixing member (550) may be shorter than the length of the second side of the laminated portion (142). This may be to minimize the portion covered by the fixing member (550) in the open portion (146).

[0139] At this time, in the present embodiment, the fixing member (550) may be configured in multiple pieces to supplement the fixing force and support force. In addition, the multiple fixing members (550) may be arranged in a direction parallel to the second side (X-axis direction).

[0140] Accordingly, a strong force can be applied to support or fix the laminate (140) by multiple fixing members (550). In addition, since the opening (146) located between the fixing members (550) is not blocked by the fixing members (550), gas discharge through the opening (146) can also be smoothly achieved.

[0141] Hereinafter, among the plurality of fixing members (550), the fixing member (550) located at the frontmost position (positive direction of the X-axis) is referred to as the first fixing member, and the fixing member (550) located at the rearmost position (negative direction of the X-axis) is referred to as the second fixing member.

[0142] At this time, in the present embodiment, the first fixing member and the second fixing member may be positioned adjacent to each end of the laminate (142) in a direction parallel to the second side (X-axis direction). This may be to allow the support force and fixing force of the fixing member (550) to be applied more effectively to the laminate (140).

[0143] Here, the fact that the fixing member (550) is positioned adjacent to the end of the laminated portion (142) may mean that the fixing member (550) is positioned closer to the end than to the central portion of the laminated portion (142).

[0144] Meanwhile, in the present embodiment, a communication hole (553) may be formed in a portion (552) covering the opening (146) of the fixing member (550). At this time, the communication hole (553) may be configured in the same manner as the communication hole (457) (illustrated in FIG. 7) described in the fifth embodiment. Through this, the obstruction of gas flow by the fixing member (550) may be minimized.

[0145] Hereinafter, a secondary battery according to one embodiment of the present invention will be described with different drawings.

[0146] Figure 10 is a perspective view of a secondary battery according to one embodiment of the present invention, viewed from above. Here, the electrode assembly housed within the pouch is indicated by a dotted line.

[0147] Fig. 10 discloses a secondary battery (1) according to one embodiment of the present invention. Referring to Fig. 10, the secondary battery (1) according to one embodiment of the present invention may be a battery capable of charging or discharging electrical energy multiple times.

[0148] To this end, a secondary battery (1) according to one embodiment of the present invention may include the electrode assembly (30, 130, 230, 330, 430, 530) (hereinafter referred to as 30 to 530) (illustrated in FIGS. 1 to 9) described above. Hereinafter, a description will be given on the premise that a secondary battery (1) according to one embodiment of the present invention includes an electrode assembly (30) according to the first embodiment of the present invention.

[0149] Meanwhile, a secondary battery (1) according to one embodiment of the present invention may include a pouch (10). In this embodiment, the pouch (10) may be a casing for accommodating the electrode assembly (30) described above and protecting it from the outside.

[0150] In this embodiment, the pouch (10) may include a receiving portion (12). The receiving portion (12) may be a portion of the pouch (10) for providing a receiving space (S) (illustrated in FIG. 14) in which the electrode assembly (30) is received.

[0151] In this embodiment, the pouch (10) may include a terrace portion (14). The terrace portion (14) may be a portion of the pouch (10) formed along the perimeter of the receiving portion (12). The terrace portion (14) may be configured to isolate the receiving space of the receiving portion (12) from the outside.

[0152] In this embodiment, the pouch (10) may be formed by folding a single pouch sheet in half with an electrode assembly (30) therebetween. At this time, one side and the other side of the pouch sheet may be brought into contact with each other along the perimeter of the electrode assembly (30). In this way, the sides of the pouch sheet that are brought into contact by being folded in half may be sealed, thereby forming a terrace portion (14). For example, the sides may be heat-sealed.

[0153] Meanwhile, in the present embodiment, the secondary battery (1) may include an electrode lead (20). The electrode lead (20) may be a lead for electrically connecting the electrode assembly (30) to a load or power source outside the pouch (10).

[0154] To this end, the electrode lead (20) may be connected to the electrode assembly (30) on one side and may extend to the outside of the pouch (10) on the other side. The electrode lead (20) may be provided in the form of a conductive film or sheet as illustrated, but is not limited thereto, and may also be formed of a wire or a metal piece, etc.

[0155] At this time, according to the secondary battery (1) according to one embodiment of the present invention, the electrode assembly (30) may be arranged so that the opening (46) faces a portion of the terrace portion (14) of the pouch (10). At this time, the portion of the terrace portion (14) may be a portion formed by sealing the gas collection portion (14') (shown in FIG. 13).

[0156] In this embodiment, the gas collection unit (14') may be a portion of the terrace unit (14) formed by folding a single pouch sheet in half, and having an opening to allow gas in the receiving space of the receiving unit (12) to be discharged to the outside.

[0157] In this way, in this embodiment, since the opening (46) of the electrode assembly (30) is positioned toward the opening, the gas between the separators can be discharged more smoothly to the outside of the pouch (10) through the opening (46). This will be described in detail later together with the manufacturing method of a secondary battery according to one embodiment of the present invention.

[0158] Hereinafter, a method for manufacturing a secondary battery according to one embodiment of the present invention will be described with different drawings.

[0159] FIG. 11 is a flowchart of a secondary battery manufacturing method according to one embodiment of the present invention. FIG. 12 is a detailed flowchart of step S110 of FIG. 11. FIG. 13 and FIG. 14 are diagrams illustrating steps S200 and S300 according to one embodiment of the present invention.

[0160] Referring to FIGS. 1 to 11, in a method for manufacturing a secondary battery according to an embodiment of the present invention, an electrode assembly (30 to 530) is first manufactured (S100). At this time, in step S100 of the method for manufacturing a secondary battery according to an embodiment of the present invention, a laminate (40, 140) is formed (S110), and a fixing member (50, 150, 250, 350, 450, 550) is attached to the laminate (40, 140) (S120).

[0161] A laminate (40, 140) formed in step S110 of a secondary battery manufacturing method according to one embodiment of the present invention may include a laminated portion (42, 142) in which electrodes (43, 143) and separators (44, 144) are alternately interposed, and which has a first side and a second side perpendicular to the first side; an electrode tab (45, 145) connected to the electrode (43, 143) and protruding outward from the first side; and an opening (46, 146) provided on the second side of the laminated portion (42, 142) so that gas between the separators (44, 144) can flow to the outside.

[0162] Meanwhile, in step S110, the laminate (40) may be formed by a stacking process in which electrodes (43) and separators (44) are alternately laminated. Alternatively, the laminate (140) may be formed by a folding process in which a separator sheet is folded and a cutting process in which an opening (146) is formed. The latter will be described in more detail below.

[0163] Referring to FIGS. 7 to 12, in step S110 of a secondary battery manufacturing method according to one embodiment of the present invention, a separator sheet is folded along a direction parallel to the second side so that electrodes and separators are alternately interposed (S111). At this time, in step S111, the folding process may be repeated for each unit length. Here, the unit length may correspond to or be longer than the width of the electrode (143).

[0164] In this way, when the separator sheet is folded multiple times, multiple parts of the separator sheet overlap each other in the lateral direction (Y-axis direction) of the electrode (143) in the laminated portion (142), so that a folded portion (144a) can be formed on the second side of the laminated portion (142).

[0165] At this time, the gas between the separation membranes (144) may have difficulty flowing to the folded portion (144a). This is because several portions of the separation membrane sheet are overlapped in the folded portion (144a).

[0166] Next, step S110 of the secondary battery manufacturing method according to one embodiment of the present invention folds the separator sheet (S111) and forms an opening (146) in the folded portion (144a) (S112).

[0167] At this time, in step S112, the folded portion (144a) may be penetrated in the overlapping direction. This may be to allow gas between the separators (144) located most inside in the overlapping direction to flow directly to the outside.

[0168] At this time, in step S112, the folded portion (144a) can be cut from one end to the other in a direction parallel to the second side (X-axis direction). Through this, the gas between the separation membranes (144) can flow outward through the entire section along the second side of the laminated portion (142).

[0169] Of course, step S112 may also be performed by cutting only one section of the folded portion (144a) along the direction parallel to the second side (X-axis direction), or by forming a hole penetrating therethrough.

[0170] Referring to FIGS. 1 to 14, in a method for manufacturing a secondary battery according to an embodiment of the present invention, electrode assemblies (30 to 530) are manufactured (S100), and the manufactured electrode assemblies (30 to 530) are accommodated in a receiving portion (12) of a pouch (10') (S200). In this embodiment, a receiving space (S) may be provided inside the receiving portion (12), and the electrode assemblies (30 to 530) may be placed in the receiving space (S) of the receiving portion (12).

[0171] At this time, in step S200 of the secondary battery manufacturing method according to one embodiment of the present invention, the opening (46, 146) of the electrode assembly (30 to 530) may be arranged so as to face one side of the pouch (10'). At this time, one side of the pouch (10') may be the gas collection unit (14'). In other words, the electrode assembly (30 to 530) may be arranged in the receiving space (S) so as to face the opening provided in the second variant gas collection unit (14') of the stacking unit (42, 142).

[0172] Below, the aforementioned gas collection unit (14') will be described in detail.

[0173] In this embodiment, the pouch (10') may be formed by folding a single pouch sheet in half with the electrode assembly (30 to 530) interposed therebetween. Accordingly, one side and the other side of the pouch (10') may face or contact each other along the perimeter of the electrode assembly (30 to 530).

[0174] At this time, a portion of the facing surfaces of the pouch (10') may be sealed. At this time, the sealing may be performed by a heat-sealing process, but is not limited thereto. In addition, other portions may not be sealed. This may be to allow gas within the receiving space (S) to be discharged to the outside through the other portion.

[0175] Here, the gas collection portion (14') may refer to an unsealed portion among the facing surfaces of the pouch (10'). Since the facing surfaces forming the gas collection portion (14') are not sealed to each other, an opening connecting the receiving space (S) to the outside may be formed in the gas collection portion (14').

[0176] Next, in a method for manufacturing a secondary battery according to one embodiment of the present invention, an electrode assembly (30 to 530) is accommodated in a pouch (10') (S200), and gas in the accommodation space (S) is discharged (S300).

[0177] At this time, in step S300 according to one embodiment of the present invention, a predetermined electrolyte can be injected into the receiving space (S) through an opening provided at the end of the gas collection unit (14').

[0178] Next, in step S300, an opening provided at the end of the gas collection unit (14') is sealed, and a process of charging and discharging the electrode assembly (30 to 530) is performed. Accordingly, a predetermined gas may be generated between the separators of the electrode assembly (30 to 530). At this time, the sealing may be performed by a thermal bonding process, but is not limited thereto.

[0179] Next, in step S300, a predetermined hole is formed in one area of ​​the gas collection unit (14') to discharge the gas in the receiving space (S) to the outside. At this time, in the present embodiment, the openings (46, 146) of the electrode assemblies (30 to 530) are arranged toward the gas collection unit (14'), so that the gas inside the electrode assemblies (30 to 530) can be smoothly discharged to the outside of the pouch (10') through the openings (46, 146).

[0180] That is, according to the method for manufacturing a secondary battery according to the present embodiment, the gas in the receiving space (S) and the electrode assembly (30 to 530) can be discharged more effectively to the outside of the pouch (10').

[0181] Next, in a method for manufacturing a secondary battery according to one embodiment of the present invention, gas in a receiving space (S) is discharged (S300), and an area adjacent to an electrode assembly (30 to 530) in a gas collection unit (14') is sealed (S400). At this time, the sealing may be performed by a thermal bonding process, but is not limited thereto.

[0182] At this time, the area adjacent to the electrode assembly (30 to 530) in the gas collection unit (14') may be an area provided along the direction (X-axis direction) parallel to the second side of the electrode assembly (30 to 530). Accordingly, the receiving space (S) may be isolated from the portion in which a hole for discharging gas is formed in the gas collection unit (14').

[0183] Meanwhile, the gas collection unit (14') can be removed by cutting off the outer portion. Accordingly, the pouch (10') illustrated in FIGS. 13 and 14 can have a more compact shape like the pouch (10) illustrated in FIG. 10.

[0184] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0185] [Explanation of symbols]

[0186] 1: Secondary battery

[0187] 10, 10': Pouch

[0188] 20: Electrode lead

[0189] 30, 130, 230, 330, 430, 530: Electrode assembly

[0190] 40, 140: laminate

[0191] 50, 150, 250, 350, 450, 550: Fixed member

[0192] S: Reception space

Claims

1. A laminated portion having a first side and a second side perpendicular to the first side, wherein electrodes and separators are alternately arranged; An electrode tab connected to the above electrode and protruding outwardly through the separator at the first side of the above laminated portion; An opening provided on the second side of the laminated portion so that gas between the membranes can flow to the outside; and An electrode assembly comprising a fixing member that fixes the electrode and separator and covers at least a portion of the opening.

2. In paragraph 1, The above fixed member is, A first fixing member attached to one surface of the above laminated member; A second fixing member attached to the other surface of the above laminated member; and An electrode assembly comprising a connecting portion that connects the first fixing portion and the second fixing portion and covers at least a portion of the opening.

3. In paragraph 2, The above opening extends in the longitudinal direction of the laminated portion, The above-mentioned fixing member is an electrode assembly provided along the longitudinal direction of the above-mentioned laminated portion.

4. In paragraph 2, The above connecting part is an electrode assembly made of a porous material that allows gas to pass between the separators.

5. In paragraph 2, An electrode assembly, wherein a communication hole communicating with the opening is formed in the above connecting portion.

6. In paragraph 5, An electrode assembly having a plurality of the above communication holes.

7. In paragraph 1, The above-mentioned fixed member is an electrode assembly having a ring shape surrounding the periphery of the laminated portion.

8. In paragraph 1, An electrode assembly in which the above-mentioned fixing member is composed of a plurality of pieces and arranged along a direction parallel to the second side of the laminated portion.

9. In paragraph 8, The above plurality of fixed members are, An electrode assembly comprising a first fixing member and a second fixing member respectively adjacent to each end of the second side of the laminated portion in a direction parallel to the second side.

10. In paragraph 1, The above opening is an electrode assembly formed by cutting the separator from one end to the other in a direction parallel to the second side.

11. In paragraph 1, An electrode assembly, wherein the above openings are provided on opposite sides of the laminated portion.

12. In paragraph 1, The above-mentioned fixing member is an electrode assembly made of tape.

13. A pouch having a storage space inside; and Including an electrode assembly arranged in the above-mentioned receiving space, The above electrode assembly is, A laminated portion having a first side and a second side perpendicular to the first side, wherein electrodes and separators are alternately disposed; An electrode tab connected to the above electrode and protruding outwardly through the separator at the first side of the above laminated portion; An opening provided on the second side of the laminated portion so that gas between the membranes can flow to the outside; and A secondary battery comprising a fixing member that fixes the electrode and separator and covers at least a portion of the opening.

14. Step of manufacturing an electrode assembly; A step of accommodating the above electrode assembly in the receiving space of the pouch; A step of discharging the gas in the receiving space to one side of the pouch; and Comprising a step of sealing the above pouch, The steps of manufacturing the above electrode assembly are: A step of forming a laminate, which comprises a laminate having a first side and a second side perpendicular to the first side, electrode tabs connected to the electrodes and protruding outwardly from the first side of the laminate, and an opening provided on the second side of the laminate so that gas between the electrodes and the separator can flow to the outside; and A method for manufacturing a secondary battery, comprising the step of attaching a fixing member covering at least a portion of the opening to the laminate to fix the electrode and separator.

15. In paragraph 14, A method for manufacturing a secondary battery, wherein in the step of accommodating the electrode assembly in the receiving space, the opening of the electrode assembly is positioned so as to face one side of the pouch.

16. In paragraph 14, The step of forming the above laminate is: A step of folding the separator sheet along a direction parallel to the second side so that the electrodes and the separator are alternately interposed; and A method for manufacturing a secondary battery, comprising the step of forming the opening in a portion folded along the second side of the separator sheet.

17. In paragraph 16, In the step of folding the above separator sheet, several parts of the separator sheet overlap each other in the lateral direction of the electrode, and the folded part is formed. A method for manufacturing a secondary battery, wherein in the step of forming the above-mentioned opening, the folded portion penetrates in the above-mentioned overlapping direction.

18. In paragraph 16, A method for manufacturing a secondary battery, wherein in the step of forming the opening, the folded portion is cut from the separator sheet or a communication hole is formed in the folded portion from the separator sheet.

19. In paragraph 18, A method for manufacturing a secondary battery, wherein in the step of forming the above-mentioned opening, the folded portion of the separator sheet is cut from one end to the other end in a direction parallel to the second side.

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