Battery assembly

Abstract

The present invention relates to a battery assembly and, more specifically, to a battery assembly including rechargeable batteries capable of charging / discharging. A battery assembly according to an embodiment of the present invention includes: a plurality of rechargeable batteries; and a housing accommodating the plurality of rechargeable batteries. Each of the rechargeable batteries includes: an electrode assembly; an accommodation unit which accommodates the electrode assembly; an exterior cladding having an exterior cladding opening which communicates the inner space of the accommodation unit with the outside; and a cover member covering the exterior cladding opening, wherein parts of the exterior cladding overlap each other to form an exterior cladding overlapping part, and the exterior cladding overlapping part may be in close contact between the accommodation unit and the housing or between the accommodation unit and a neighboring rechargeable battery.

Description

Battery assembly

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0030248, filed February 29, 2024, and Korean Patent Application No. 10-2025-0025259, filed February 26, 2025, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a battery assembly, and more particularly, to a battery assembly including secondary batteries capable of being charged and discharged.

[0005] Unlike primary batteries, which are non-rechargeable, secondary batteries (rechargeable batteries) are rechargeable and dischargeable. Small secondary batteries are used in portable electronic devices such as cell phones, laptops, and camcorders, while medium- or large-sized secondary batteries are widely used as power sources for motors in hybrid vehicles and other vehicles.

[0006] Secondary batteries can be classified into various types depending on the type of outer packaging material that houses the electrode assembly. For example, secondary batteries can be classified into square secondary batteries in which the electrode assembly is housed inside a square metal can, cylindrical secondary batteries in which the electrode assembly is housed inside a cylindrical metal can, and pouch-type secondary batteries in which the electrode assembly is housed inside a pouch.

[0007] These pouch-type secondary batteries can be housed in a housing made of resin or metal to form a battery assembly (battery module and / or battery pack). Here, some of the pouches of the pouch-type secondary batteries can be joined to each other to form a pouch joint.

[0008] In the past, to prevent the pouch joint from bursting when the internal pressure of the pouch increased, a separate sealing member with a certain volume was used to secure the pouch joint. While this improved the sealing strength of the pouch joint, the volume occupied by the sealing member lowered the energy density of the entire battery assembly.

[0009] The present invention has been conceived in recognition of the above problems, and an object of the present invention is to improve the sealing force of a pouch-type secondary battery accommodated in a battery assembly without using an additional sealing member.

[0010] According to one embodiment of the present invention, a battery assembly comprises: a plurality of secondary batteries; and a housing for accommodating the plurality of secondary batteries, wherein the secondary batteries include: an electrode assembly; an outer material having a receiving portion for accommodating the electrode assembly, and an outer material opening for communicating an internal space of the receiving portion with the outside; and a cover member for covering the outer material opening, wherein portions of the outer materials overlap each other to form an outer material overlapping portion, and the outer material overlapping portion can be in close contact between the receiving portion and the housing, or between the receiving portion and adjacent secondary batteries.

[0011] The above outer material may be composed of a laminate sheet including a metal layer and a resin layer formed on at least one surface of the metal layer.

[0012] At least a portion of the overlapping portions of the above outer materials may be bonded or fused to each other.

[0013] Electrode tabs protrude from both longitudinal sides of the electrode assembly, and the overlapping portion of the outer material can be folded to one width-direction side or one height-direction side of the electrode assembly.

[0014] The above secondary battery may further include a fixing film that fixes the folded outer covering portion.

[0015] The above plurality of secondary batteries can be arranged in a horizontal row inside the housing.

[0016] The overlapping outer shell of the plurality of secondary batteries can be tightly fitted between the receiving portion and the lower wall of the housing.

[0017] Meanwhile, a battery assembly according to one embodiment of the present invention may further include a fixing member that fixes a plurality of the secondary batteries to the lower wall of the housing.

[0018] The above-mentioned fixing member may include a resin that is cured in contact with the overlapping portion of the outer shell of each of the plurality of secondary batteries.

[0019] The plurality of secondary batteries may be sandwiched between two side walls of the housing so as to be pressed horizontally by the housing.

[0020] Meanwhile, in a battery assembly according to another embodiment of the present invention, a plurality of the overlapping outer casing portions may be arranged in a row along a horizontal direction.

[0021] The above outer overlapping portion can be in close contact with the adjacent secondary battery or both side walls of the housing.

[0022] The plurality of said outer casing overlapping portions may include a plurality of first outer casing overlapping portions arranged in a horizontal line; and a plurality of second outer casing overlapping portions arranged in a horizontal line above the first outer casing overlapping portions.

[0023] One of the adjacent pair of secondary batteries may include the first outer covering overlapping portion, and the other of the adjacent pair of secondary batteries may include the second outer covering overlapping portion.

[0024] A pair of adjacent first outer material overlapping portions and a pair of adjacent second outer material overlapping portions may be provided between the facing surfaces of a pair of adjacent secondary batteries.

[0025] The above cover member may be formed with a lead insertion hole into which an electrode lead is inserted.

[0026] The overlapping outer shell of the plurality of secondary batteries can be tightly fitted between the receiving portion and the upper wall of the housing.

[0027] According to a battery assembly according to one embodiment of the present invention, since the overlapping portion of the outer material is pressed inward by the inner wall of the housing or an adjacent secondary battery, the overlapping portion of the outer material can be prevented from bursting even when the internal pressure of the outer material increases.

[0028] FIG. 1 is a perspective view showing the overall structure of a battery assembly according to a first embodiment of the present invention.

[0029] Figure 2 is an exploded perspective view of a secondary battery accommodated in the battery assembly of Figure 1.

[0030] Figure 3 is a drawing for explaining the formation of a sealing portion in the secondary battery of Figure 2.

[0031] Figure 4 is a drawing for explaining the attachment of a fixed film to the secondary battery of Figure 2.

[0032] Fig. 5 is a drawing showing the internal structure of the battery assembly according to Fig. 1.

[0033] FIG. 6 is a drawing showing the internal structure of a battery assembly according to a second embodiment of the present invention.

[0034] FIG. 7 is a drawing showing the internal structure of a battery assembly according to a third embodiment of the present invention.

[0035] FIG. 8 is a drawing showing the internal structure of a battery assembly according to a fourth embodiment of the present invention.

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0037] 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.

[0038] 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.

[0039] Hereinafter, a battery assembly according to the present invention will be described with reference to the drawings.

[0040]

[0041] Example 1

[0042] FIG. 1 is a perspective view showing the overall structure of a battery assembly according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of a secondary battery accommodated in the battery assembly of FIG. 1.

[0043] Referring to FIGS. 1 and 2, a battery assembly (10) according to a first embodiment of the present invention may include a plurality of secondary batteries (100) and a housing (200) that accommodates these secondary batteries (100). Here, each of the plurality of secondary batteries (100) accommodated inside the housing (200) may include an electrode assembly (110) in which electrodes (111) and separators (112) are alternately arranged; an outer material (120) having a receiving portion (120a) that accommodates the electrode assembly (110) and an outer material opening (121) that communicates an internal space (S) of the receiving portion (120a) with the outside; and a cover member (130) that covers the outer material opening (121).

[0044] At this time, parts of the outer material (120) overlap each other to form an outer material overlapping portion (122), and the outer material overlapping portion (122) can be tightly fitted between the receiving portion (120a) and the housing (200). In this case, the outer material overlapping portion (122) is pressed inward by the inner wall of the housing (200) or the adjacent secondary battery (100), so that even when the internal pressure of the outer material (120) increases, the outer material overlapping portion (122) can be prevented from bursting.

[0045] In addition, in the battery assembly (10) according to the first embodiment of the present invention, a sealing member having volume is not additionally attached to the outer overlapping portion (122) of the secondary battery (100), so that the outer overlapping portion (122) can be prevented from bursting without increasing the volume of the secondary battery (100). Therefore, the battery assembly (10) according to the first embodiment of the present invention has the advantageous effect of improving the energy density of the battery assembly (10) compared to the case where a sealing member having volume is attached to the outer overlapping portion (122).

[0046] The battery assembly (10) is a battery assembly in which a plurality of secondary batteries (100) are electrically connected, and can be configured in various ways. For example, the battery assembly (10) can be a battery module in which a plurality of secondary batteries (100) are housed in a module housing, or a cell-to-pack in which a plurality of secondary batteries (100) are housed in a pack housing.

[0047] A secondary battery (100) is a battery that can be repeatedly charged and discharged, and can be configured in various ways. For example, the secondary battery (100) can be a pouch cell in which an electrode assembly (110) in which electrodes (111) and separators (112) are alternately arranged is wrapped in a sheet-shaped outer material (120).

[0048] The electrode (111) can be a positive electrode or a negative electrode. Here, the positive electrode includes a positive electrode current collector and a positive electrode active material coated on the positive electrode current collector, and the negative electrode includes a negative electrode current collector and a negative electrode active material coated on the negative electrode current collector. The separator (112) is a membrane made of an insulating material interposed between the positive electrode and the negative electrode to block contact between the positive electrode and the negative electrode, and a plurality of pores through which positive ions pass can be formed in the separator (112).

[0049] The outer shell (120) may be a pouch-shaped outer shell composed of a laminate sheet including a metal layer such as aluminum or stainless steel and one or more resin layers. Here, the resin layer may be formed on at least one of the outer surface and the inner surface of the metal layer. A receiving portion (120a) for receiving the electrode assembly (110) may be formed inside the outer shell (120). In addition, both sides of the receiving portion (120a) may be connected to the outside.

[0050] The metal layer constituting the outer material (120) can serve as a substrate that maintains mechanical strength and a barrier layer that prevents the penetration of moisture and oxygen. In addition to the function of preventing the inflow or leakage of foreign substances such as gas and moisture, the metal layer can be composed of aluminum or an aluminum alloy so that it can have the function of improving the strength of the battery case. Alloy numbers 8079, 1N30, 8021, 3003, 3004, 3005, 3104, 3105, etc. can be used as the aluminum alloy, and these can be used alone or in combination of two or more.

[0051] The first resin layer coated on the outer surface of the metal layer must have excellent resistance to the external environment in order to protect the electrode assembly from the outside. Therefore, the first resin layer is required to have excellent tensile strength and corrosion resistance relative to its thickness. For the first resin layer, a polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polyolefin resin such as polyethylene or polypropylene, etc. can be used.

[0052] The second resin layer coated on the inner surface of the metal layer can be combined with a cover member (130) described later to seal the receiving portion (120a), and the second resin layer can be composed of a polyolefin series resin. For example, CPP (Casted Polypropylene), chlorinated polypropylene, polyethylene, ethylene propylene copolymer, polyethylene and acrylic acid copolymer, and polypropylene and acrylic acid copolymer can be used for the second resin layer.

[0053] Conventionally, a pouch-type secondary battery has been manufactured by forming a cup portion on a pouch film, inserting an electrode assembly into the cup portion, and then sealing the pouch film with the formed cup portion with another pouch film. However, due to the material properties of the pouch film, there was a limit to the forming depth of the cup portion, making it impossible to form the cup portion deeply to increase the capacity of the secondary battery. Furthermore, during the forming process of the cup portion, the thickness of the pouch film was reduced, which caused problems such as cracks to occur in the pouch film.

[0054] On the other hand, the outer casing (120) of the secondary battery (100) according to the present invention may be composed of a rolled or folded laminate sheet. Therefore, the secondary battery (100) according to the present invention can accommodate the electrode assembly (110) in the receiving portion (120a) of the outer casing (120) without a separate cup portion molding. In this case, since the conventional limitation due to the formation of the cup portion in the outer casing is not applied, the capacity of the secondary battery (100) can be improved by increasing the size of the receiving portion (120a). In addition, since the outer casing (120) prepared by rolling or folding the laminate sheet does not have a portion where the thickness is reduced, the occurrence of defects such as cracks in the outer casing (120) can be prevented.

[0055] For reference, the secondary battery (100) according to the present invention can be formed by rolling or folding the laminate sheet after the electrode assembly (110) is placed on the upper surface of the unfolded laminate sheet. In addition, the secondary battery (100) according to the present invention can be formed by rolling or folding the laminate sheet to form a receiving portion (120a), an outer covering overlapping portion (122), and an outer covering opening (121), and then inserting the electrode assembly (110) into the outer covering opening (121). In both of the above cases, the electrode assembly (110) can be accommodated inside the outer covering (120) without forming a separate cup portion.

[0056] At this time, the outer material overlapping portion (122) is formed by joining one end and the other end of the laminate sheet, and this outer material overlapping portion (122) can be folded to one side in the width direction or one side in the height direction of the secondary battery (100). In the case of the battery assembly (10) according to the first embodiment of the present invention, the outer material overlapping portion (122) can be folded to one side in the height direction of the secondary battery (100).

[0057] Meanwhile, the cover member (130) is inserted into the outer material opening (121) to seal the inner space (S) of the receiving portion (120a), and may be configured in various ways. For example, the cover member (130) may include a body (131) in which a portion coupled to the outer material (120) is formed flat, and a lead insertion hole (132) through which an electrode lead (114) passes may be formed in this body (131).

[0058] The electrode lead (114) passing through the lead insertion port (132) can be connected to the electrode tab (113) to which the electrodes (111) are welded. In addition, the lead insertion port (132) can have a shape corresponding to the shape of the electrode lead (114). A sealing member such as an O-ring can be interposed between the lead insertion port (132) and the electrode lead (114), or a sealant layer made of a thermoplastic resin can be formed. In this case, it is possible to prevent the electrolyte injected into the receiving portion (120a) from leaking through the lead insertion port (132).

[0059] Meanwhile, FIG. 3 is a drawing for explaining the formation of a sealing portion in the secondary battery of FIG. 2.

[0060] Referring to FIG. 3, at least a portion of the overlapping portions (122) of the outer materials may be bonded or fused to each other. That is, a portion of the overlapping portions (122) of the outer materials that are bonded or fused to each other may form a sealing portion (123). This sealing portion (123) may be formed at various locations of the overlapping portions (122) of the outer materials.

[0061] For example, the sealing portion (123) may be formed only on a portion of the exterior material overlapping portion (122). If the sealing portion (123) is formed on the entire area of ​​the exterior material overlapping portion (122), there is a problem that the exterior material overlapping portion (122) is damaged by the sealing. However, the above problem can be solved by forming the sealing portion (123) only on a portion of the exterior material overlapping portion (122).

[0062] In addition, as illustrated in FIG. 3, the sealing portion (123) may be formed on the innermost side of the outer material overlapping portion (122). In this case, there is an advantageous effect of improving the sealing force compared to when the sealing portion (123) is formed at another location on the outer material overlapping portion (122).

[0063] The sealing portion (123) may be formed in a long straight line at the innermost side of the exterior material overlapping portion (122). Specifically, the sealing portion (123) may have a shape that extends in a long straight line from one innermost end of the exterior material overlapping portion (122) toward the other innermost end of the exterior material overlapping portion (122). At this time, the sealing portion (123) may have various widths. For example, the sealing portion (123) may be formed in a long straight line at the innermost side of the exterior material overlapping portion (122) with a width of between 8 and 12 mm.

[0064] Meanwhile, FIGS. 2 and 3 illustrate the length direction (S1), height direction (S2), and width direction (S3) of the electrode assembly (110). Referring to FIGS. 2 and 3, electrode tabs (113) protrude from both sides of the length direction of the electrode assembly (110), and the outer overlapping portion (122) can be folded to one side of the electrode assembly (110) in the width direction (S3). In addition, although not illustrated in FIGS. 2 and 3, the outer overlapping portion (122) can also be folded to one side of the electrode assembly (110) in the height direction (S2).

[0065] Meanwhile, FIG. 4 is a drawing for explaining the attachment of a fixed film to the secondary battery of FIG. 2.

[0066] Referring to FIG. 4, the secondary battery (100) may include a fixing film (140) that fixes the outer covering overlapping portion (122) folded to one side. This fixing film (140) has fixing power and various thin materials may be applied. For example, the fixing film (140) may be a fixing tape having an adhesive layer formed on one or both sides. In this way, the fixing film (140) that fixes the outer covering overlapping portion (122) is formed to be extremely thin, so that even when attached to the secondary battery (100), the increase in volume or weight thereof can be minimized.

[0067] Meanwhile, the fixed film (140) adheres the folded outer overlapping portion (122) to the outer surface of the secondary battery (100), thereby fixing the position of the outer overlapping portion (122) to the surface of the secondary battery (100). This fixed film (140) can be attached to various positions of the secondary battery (100).

[0068] As illustrated in FIG. 4, the fixing film (140) can be attached to one side in the width direction of the secondary battery (100) so as to bring the end of the outer overlapping portion (122) into close contact with the outer surface of the secondary battery (100). In addition, although not illustrated in the drawing, when the outer overlapping portion (122) is folded to one side in the height direction of the secondary battery (100), the fixing film (140) can be attached to one side in the height direction of the secondary battery (100).

[0069] Meanwhile, FIG. 5 is a drawing showing the internal structure of the battery assembly according to FIG. 1.

[0070] Referring to FIG. 5, a plurality of secondary batteries (100) are arranged in a horizontal line (H) inside a housing (200), and an outer material overlapping portion (122) formed on each of the plurality of secondary batteries (100) can be in close contact between the receiving portion (120a) and the lower wall (210) of the housing (200). That is, all of the outer material overlapping portions (122) formed on each of the plurality of secondary batteries (100) can come into contact with the lower wall (210) of the housing (200).

[0071] In this case, the outer material overlapping portion (122) is pressurized by the weight of the secondary battery (100), so that even when the internal pressure of the outer material (120) increases, the outer material overlapping portion (122) can be prevented from bursting. In particular, since a sealing member having volume is not combined with the outer material overlapping portion (122) of the secondary battery (100), the outer material overlapping portion (122) can be prevented from bursting without increasing the volume of the secondary battery (100).

[0072] Meanwhile, the battery assembly (10) may include a fixing member (not shown) that fixes a plurality of secondary batteries (100) to the lower wall (210) of the housing (200). At this time, the fixing member may be a resin that is cured while in contact with the outer covering overlapping portion (122) of each of the plurality of secondary batteries (100).

[0073] Specifically, a liquid resin is applied to the lower wall (210) of the housing (200), and then a plurality of secondary batteries (100) can be placed inside the housing (200). At this time, the liquid resin can be hardened while in contact with one surface of the secondary batteries (100) to fix the positions of the secondary batteries (100) inside the housing (200).

[0074] The resin applied to the lower wall (210) of the housing (200) can be cured while the outer covering overlapping portion (122) of each of the plurality of secondary batteries (100) is in contact with the folded surface. In this case, the outer covering overlapping portion (122) is fixed to one surface of the secondary battery (100) in a folded state, so that the outer covering overlapping portion (122) can be prevented from being crumpled even when the secondary batteries (100) are repeatedly charged and discharged.

[0075]

[0076] Second Example

[0077] The secondary battery according to the second embodiment of the present invention differs from the first embodiment in that the overlapping outer casings are arranged in a horizontal line. The second embodiment will be described with a focus on the differences, omitting any commonalities with the first embodiment as much as possible. It should be understood that any details not described in the second embodiment, if necessary, may be considered as those described in the first embodiment.

[0078] FIG. 6 is a drawing showing the internal structure of a battery assembly according to a second embodiment of the present invention.

[0079] Referring to FIG. 6, a battery assembly (10a) according to a second embodiment of the present invention may include a plurality of secondary batteries (100a) and a housing (200a) that accommodates the secondary batteries (100a). Here, the outer covering overlapping portion (122a) of each of the plurality of secondary batteries (100a) may be folded to one side of the electrode assembly (110a). In particular, in the battery assembly (10a) according to the second embodiment of the present invention, the outer covering overlapping portion (122a) of each of the plurality of secondary batteries (100a) may be folded to one side in the vertical direction (V) of FIG. 6.

[0080] A plurality of secondary batteries (100a) may be sandwiched between left and right side walls (220a, 230a) of the housing (200a) so as to be pressed in the horizontal direction (H) by the housing (200a). Here, the outer covering overlapping portions (122a) formed on each of the plurality of secondary batteries (100a) may be arranged in a row along the horizontal direction (H) within the housing (200a). That is, the secondary batteries (100a) may be accommodated within the housing (200a) such that the folded outer covering overlapping portions (122a) face the horizontal direction (H).

[0081] Here, the outer overlapping portion (122a) may be in contact with the left and right side walls (220a, 230a) of the adjacent secondary battery (100a) or the housing (200a). Specifically, as illustrated in FIG. 6, the outer overlapping portions (122a) of the secondary batteries (100a) placed inside the housing (200a) may all be arranged to the right. In addition, the outer overlapping portion (122a) of one of the secondary batteries (100a) accommodated in the housing (200a) may be in close contact with the right wall (230a) of the adjacent secondary battery (100a) or the housing (200a).

[0082] In this case, the outer material overlapping portion (122a) of one secondary battery (100a) accommodated in the housing (200a) may be in close contact with the receiving portion of an adjacent secondary battery (100a) or the right wall (230a) of the housing (200a). That is, the outer material overlapping portion (122a) of one secondary battery (100a) may be in close contact between the receiving portion of one secondary battery (100a) and the receiving portion of another adjacent secondary battery (100a), or the outer material overlapping portion (122a) of one secondary battery (100a) may be in close contact between the receiving portion of one secondary battery (100a) and the right wall (230a) of the housing (200a).

[0083] Meanwhile, although not shown in the drawing, the outer overlapping portions (122a) of the secondary batteries (100a) arranged inside the housing (200a) may all be arranged on the left side. In this case, the outer overlapping portion (122a) of one secondary battery (100a) accommodated in the housing (200a) may be in close contact with the receiving portion of the neighboring secondary battery (100a) or the left wall (220a) of the housing (200a). That is, the outer overlapping portion (122a) of one secondary battery (100a) may be in close contact between the receiving portion of the one secondary battery (100a) and the receiving portion of another neighboring secondary battery (100a), or the outer overlapping portion (122a) of one secondary battery (100a) may be in close contact between the receiving portion of the one secondary battery (100a) and the left wall (220a) of the housing (200a).

[0084] In the battery assembly (10a) according to the second embodiment of the present invention, the outer material overlapping portion (122a) formed on each of the plurality of secondary batteries (100a) is pressed inward by the left and right side walls (220a, 230a) of the adjacent secondary battery (100a) or the housing (200a), so that even when the internal pressure of the outer material (120a) increases, the outer material overlapping portion (122a) can be prevented from bursting.

[0085] In addition, in the battery assembly (10a) according to the second embodiment of the present invention, a sealing member having volume is not bonded to the outer overlapping portion (122a) of the secondary battery (100a), so that the outer overlapping portion (122a) can be prevented from bursting without increasing the volume of the secondary battery (100a). Therefore, the battery assembly (10a) according to the second embodiment of the present invention has the advantageous effect of improving the energy density of the battery assembly (10a) compared to the case where a sealing member is bonded to the outer overlapping portion (122a).

[0086]

[0087] Third Example

[0088] The secondary battery according to the third embodiment of the present invention differs from the first and second embodiments in that the multiple outer covering overlapping portions are composed of a first outer covering overlapping portion and a second outer covering overlapping portion. The commonalities with the first and second embodiments will be omitted as much as possible, and the third embodiment will be described focusing on the differences. In other words, it should be apparent that any content not described in the third embodiment, if necessary, may be considered as the content of the first and second embodiments.

[0089] FIG. 7 is a drawing showing the internal structure of a battery assembly according to a third embodiment of the present invention.

[0090] Referring to FIG. 7, a battery assembly (10b) according to a third embodiment of the present invention may include a plurality of secondary batteries (100b) and a housing (200b) that accommodates the secondary batteries (100b). Here, the outer covering overlapping portion (122b) of each of the plurality of secondary batteries (100b) may be folded to one side or the other side of the electrode assembly (110b). In particular, in the battery assembly (10b) according to the third embodiment of the present invention, the outer covering overlapping portions (122b', 122b˝) of each of the plurality of secondary batteries (100b) may be folded to one side or the other side in the vertical direction (V) of FIG. 7.

[0091] A plurality of secondary batteries (100b) may be sandwiched between left and right side walls (220b, 230b) of the housing (200b) so as to be pressed in the horizontal direction (H) by the housing (200b). Here, the plurality of outer material overlapping portions (122b) may include a plurality of first outer material overlapping portions (122b´) arranged in a row along the horizontal direction (H); and a plurality of second outer material overlapping portions (122b˝) arranged in a row along the horizontal direction (H) above the first outer material overlapping portions (122b´).

[0092] Here, the outer overlapping portions (122b´, 122b˝) can be closely attached by a pair of adjacent secondary batteries (100b). Specifically, as illustrated in FIG. 7, a pair of adjacent first outer overlapping portions (122b´) and second outer overlapping portions (122b˝) can be provided between the facing surfaces of a pair of adjacent secondary batteries (100b).

[0093] That is, the first outer material overlapping portion (122b´) may be an outer material overlapping portion of a primary secondary battery (100b), and the second outer material overlapping portion (122b˝) may be an outer material overlapping portion of another secondary battery (100b) adjacent to the primary secondary battery (100b).

[0094] That is, a pair of adjacent secondary batteries (100) can face each other so that the outer overlapping portions (122b´, 122b˝) are provided on the same side. In this case, the volume occupied by the outer overlapping portions (122b´, 122b˝) in the horizontal direction (H) can be minimized, thereby minimizing the waste of space in the horizontal direction (H) of the housing (200b).

[0095] In the battery assembly (10b) according to the third embodiment of the present invention, the outer material overlapping portions (122b´, 122b˝) formed in each of the plurality of secondary batteries (100b) are pressed inward by the adjacent secondary batteries (100b), so that even when the internal pressure of the outer material (120b) increases, the outer material overlapping portions (122b´, 122b˝) can be prevented from bursting.

[0096] In addition, in the battery assembly (10b) according to the third embodiment of the present invention, a sealing member having volume is not coupled to the outer overlapping portion (122b´, 122b˝) of the secondary battery (100), so that the outer overlapping portion (122b´, 122b˝) can be prevented from bursting without increasing the volume of the secondary battery (100b). Therefore, the battery assembly (10b) according to the third embodiment of the present invention has the advantageous effect of improving the energy density of the battery assembly (10b) compared to the case where it is coupled to the outer overlapping portion (122b´, 122b˝).

[0097]

[0098] Example 4

[0099] The secondary battery according to the fourth embodiment of the present invention differs from the first to third embodiments in that the multiple overlapping outer casing portions are in close contact with the upper wall of the housing of the secondary battery. Commonalities with the first to third embodiments will be omitted as much as possible, and the fourth embodiment will be described focusing on the differences. In other words, it should be apparent that any details not described in the fourth embodiment, if necessary, may be considered as those of the first to third embodiments.

[0100] FIG. 8 is a drawing showing the internal structure of a battery assembly according to a fourth embodiment of the present invention.

[0101] Referring to FIG. 8, a battery assembly (10c) according to a fourth embodiment of the present invention may include a plurality of secondary batteries (100c) and a housing (200c) that accommodates the secondary batteries (100c). Here, the outer covering overlapping portion (122c) of each of the plurality of secondary batteries (100c) may be folded to one side of the secondary battery (100c). In particular, in the battery assembly (10c) according to the fourth embodiment of the present invention, the outer covering overlapping portion (122c) of each of the plurality of secondary batteries (100c) may be folded to one side in the horizontal direction (H) of FIG. 8.

[0102] A plurality of secondary batteries (100a) may be sandwiched between left and right side walls (220a, 230a) of the housing (200a) so as to be pressed in the horizontal direction (H) by the housing (200a). Here, the outer covering overlapping portions (122a) formed on each of the plurality of secondary batteries (100a) may be arranged in a row along the horizontal direction (H) within the housing (200a). That is, the secondary batteries (100a) may be accommodated within the housing (200a) such that the folded outer covering overlapping portions (122a) face the horizontal direction (H).

[0103] Here, the outer material overlapping portion (122c) of each of the plurality of secondary batteries (100c) can be closely fitted between the receiving portion of the secondary battery (100c) and the upper wall (240c) of the housing (200). In this case, the outer material overlapping portion (122c) of each of the plurality of secondary batteries (100c) is pressed toward the receiving portion by the upper wall (240c) of the housing (200c), so that even when the internal pressure of the outer material (120c) increases due to charging and discharging of the secondary battery (100c), the outer material overlapping portion (122c) can be prevented from bursting.

[0104] 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.

[0105]

[0106] [Explanation of symbols]

[0107] 10: Battery assembly 100: Secondary battery

[0108] 110: Electrode assembly 111: Electrode

[0109] 112: Separator 113: Electrode tab

[0110] 114: Electrode lead 120: Sheath

[0111] 121: Exterior opening 122: Exterior overlap

[0112] 123: Sealing part 130: Cover member

[0113] 131: Body 132: Lead insertion port

[0114] 140: Fixed member 200: Housing

[0115] 210: Housing lower side wall 220, 230: Housing left and right side walls

Claims

1. A plurality of secondary batteries; and A housing comprising a plurality of secondary batteries, The above secondary battery, electrode assembly; An outer material having a receiving portion for receiving the electrode assembly and an outer material opening for communicating the inner space of the receiving portion with the outside; and Includes a cover member covering the above exterior opening, Some of the above exterior materials overlap each other to form an exterior material overlap, A battery assembly in which the above outer overlapping portion is in close contact between the receiving portion and the housing, or between the receiving portion and an adjacent secondary battery.

2. In claim 1, A battery assembly in which the outer covering is composed of a laminate sheet including a metal layer and a resin layer formed on at least one surface of the metal layer.

3. In claim 1, A battery assembly in which at least a portion of the overlapping portions of the above outer materials are bonded or fused to each other.

4. In claim 1, Electrode tabs protrude from both longitudinal sides of the above electrode assembly, A battery assembly in which the above outer material overlapping portion is folded to one side in the width direction or one side in the height direction of the electrode assembly.

5. In claim 4, A battery assembly wherein the secondary battery further includes a fixing film that fixes the folded outer covering portion.

6. In claim 4, A battery assembly in which the plurality of secondary batteries are arranged in a horizontal row inside the housing.

7. In claim 6, A battery assembly in which the outer overlapping portion of the plurality of secondary batteries is in close contact between the receiving portion and the lower wall of the housing.

8. In claim 1, A battery assembly further comprising a fixing member for fixing a plurality of the secondary batteries to the lower wall of the housing.

9. In claim 8, The above fixed member is, A battery assembly comprising a cured resin in contact with the overlapping outer surface of each of the plurality of secondary batteries.

10. In claim 6, A battery assembly in which the plurality of secondary batteries are sandwiched between the two side walls of the housing so as to be pressed horizontally by the housing.

11. In claim 10, A battery assembly in which a plurality of the above-described outer casing overlapping portions are arranged in a row along a horizontal direction.

12. In claim 11, A battery assembly in which the above outer overlapping portion is in close contact with the adjacent secondary battery or both side walls of the housing.

13. In claim 10, A plurality of the above-mentioned overlapping exterior materials are, A plurality of first exterior material overlapping portions arranged in a row along the horizontal direction; and A battery assembly comprising a plurality of second outer casing overlapping portions arranged in a horizontal line on the upper side of the first outer casing overlapping portion.

14. In claim 13, A battery assembly, wherein one of the adjacent pair of secondary batteries includes the first outer covering overlapping portion, and the other of the adjacent pair of secondary batteries includes the second outer covering overlapping portion.

15. In claim 14, A battery assembly in which a pair of adjacent first outer material overlapping portions and a second outer material overlapping portion are provided between the facing surfaces of a pair of adjacent secondary batteries.

16. In claim 1, A battery assembly in which a lead insertion hole into which an electrode lead is inserted is formed in the above cover member.

17. In claim 6, A battery assembly in which the outer overlapping portion of the plurality of secondary batteries is in close contact between the receiving portion and the upper wall of the housing.

Images