Battery cell and battery module

Abstract

The present disclosure relates to a battery cell and a battery module. A battery cell according to an embodiment of the present application includes: an electrode assembly including an electrode and a separator between the electrode; and a pouch-shaped case whose outer peripheral side is sealed in a state where the electrode assembly is housed inside. The electrode includes an electrode current collector and an active material layer formed on one surface or both surfaces of the electrode current collector, wherein the electrode current collector includes a protruding portion, a portion of the electrode current collector protrudes to the outside of the sealed pouch-shaped case to form the protruding portion, and a bus bar is joined to the protruding portion.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2022-0179117, filed on December 20, 2022, and Korean Patent Application No. 10-2023-0185647, filed on December 19, 2023, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to battery cells and battery modules including the same, and more specifically, to pouch cell battery cells and battery modules including the same. Background Technology

[0004] In modern society, the daily use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has spurred technological development in fields related to these mobile devices. Furthermore, rechargeable / dischargeable secondary batteries are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) in an attempt to address issues such as air pollution caused by existing gasoline vehicles using fossil fuels. Therefore, the demand for secondary batteries is growing.

[0005] Based on the shape of the external materials, lithium secondary batteries can generally be classified into can-type secondary batteries in which the electrode assembly is incorporated into a metal can, and pouch-type batteries in which the electrode assembly is incorporated into an aluminum laminate.

[0006] In the case of secondary batteries for small devices, two to three battery cells are used. However, in the case of secondary batteries for medium and large devices such as automobiles, battery modules with multiple battery cells electrically connected are used. In such battery modules, multiple battery cells are connected in series or parallel to form cell assemblies, thereby increasing capacity and output. Furthermore, one or more battery modules can be installed together with various control and protection systems such as BDU (Battery Disconnect Unit), BMS (Battery Management System), and cooling systems to form battery packs.

[0007] In conventional battery modules, busbars and busbar frames are used for electrical connections between multiple battery cells. The following will refer to... Figure 1 and Figure 2 Describe the structure of the busbars and busbar frames used in a conventional battery module.

[0008] Figure 1 This is a 3D diagram illustrating a conventional battery module. Figure 2 It is enlarged and illustrated Figure 1 A partial image of part "A". Specifically, Figure 1 An example of the battery module standing upright is shown to illustrate the appearance of the busbar frame and busbar. Figure 3 It is a cross-sectional diagram used to illustrate the connection configuration between the electrode connectors and electrode leads within the battery cells of a conventional battery module.

[0009] Reference Figures 1 to 3 The conventional battery module 10 includes: a battery cell stack 12 in which a plurality of battery cells 11 are stacked; and a busbar frame 30 disposed on both sides of the battery cell stack 12. Busbars 40 can be mounted on such busbar frames 30.

[0010] Busbar 40 is used for electrical connection between multiple battery cells 11, and the electrode leads 11L of the battery cells 11 pass through the slits formed in the busbar frame 30 and can then be bent and connected to the busbar 40. In some cases, the electrode leads 11L may also pass through the slits 40S formed in the busbar 40.

[0011] The method of connecting the electrode lead 11L to the busbar 40 is not limited, as long as an electrical connection can be made. For example, the connection can be made by welding. The battery cells 11 can be connected in series or in parallel via the busbar 40.

[0012] The battery cell 11 can be manufactured by housing an electrode assembly 11A within a pouch-type cell housing 11C, and then sealing the outer periphery of the cell housing 11C to form a seal 11S. The electrode assembly 11A may include electrodes and a separator disposed between the electrodes. Each electrode includes an electrode connector 11t, which can be connected to an electrode lead 11L by a method such as welding. More specifically, the electrode includes an electrode current collector made of a metallic material and an electrode active material layer formed by coating one or both sides of the electrode current collector with an electrode active material. A portion of this electrode current collector may extend to form the electrode connector 11t. When the outer periphery of the cell housing 11C is sealed to form the seal 11S, a lead film 11F surrounding the electrode lead 11L can be inserted between the seals 11S to improve sealing performance and ensure electrical insulation.

[0013] Electrode leads 11L protrude to the outside of the cell housing 11C, pass through the slits 30S of the busbar frame 30 and the slits 40S of the busbar 40, and can then be bent (e.g., at the bent portion 11LB) and connected to the busbar 40.

[0014] In the case of a conventional battery cell 11, the electrode connectors 11t are pre-welded to each other, the electrode connectors 11t are then welded to the electrode leads 11L, and the electrode leads 11L are welded to the busbar 40. Welding resistance may occur at three locations: the welding resistance between the electrode connectors 11t, the welding resistance between the electrode connectors 11t and the electrode leads 11L, and the welding resistance between the electrode leads 11L and the busbar 40.

[0015] The resistance of battery cell 11 affects not only its heat generation but also voltage measurement. Recently, in battery modules requiring high output, accurate voltage measurement to ensure output range and the heat generation of battery cell 11 have been major management concerns. Therefore, there is a need to develop a technology that can reduce the internal resistance of battery cells and the battery modules they comprise. Utility Model Content

[0016] Technical issues

[0017] The purpose of this disclosure is to provide a battery cell capable of reducing internal resistance and a battery module including the same.

[0018] However, the technical problems to be solved by the embodiments of this disclosure are not limited to the above-described problems, and various extensions can be made within the scope of the technical concepts included in this disclosure.

[0019] Technical solution

[0020] According to one embodiment of this disclosure, a battery cell is provided, the battery cell comprising: an electrode assembly including electrodes and a separator located between the electrodes; and a pouch-like housing, the outer periphery of which is sealed when the electrode assembly is housed within the pouch-like housing, wherein the electrodes include electrode current collectors and active material layers formed on one or both sides of the electrode current collectors; wherein the electrode current collector includes a protrusion formed such that a portion of the electrode current collector protrudes outside the sealed pouch-like housing, and wherein a busbar engages with the protrusion.

[0021] The protrusion and the busbar can be welded together.

[0022] With the protrusion engaged with the manifold, the outer periphery of the bag-shaped housing can be sealed.

[0023] The outer periphery of the bag-shaped shell can be sealed to form a sealing portion, and a membrane surrounding the protrusion can be inserted between the sealing portions.

[0024] The membrane can surround the portion of the protrusion that is exposed to the outside of the seal.

[0025] The membrane may be joined to a portion of the busbar around the protrusion and to at least a portion of the busbar.

[0026] According to another embodiment of this disclosure, a battery module is provided, the battery module comprising: a battery cell stack, wherein the battery cells are stacked in the battery cell stack, wherein busbars are connected to each other by a mechanical fastening method, thereby performing an electrical connection between the battery cells.

[0027] Mechanical fastening methods can include bolt fastening, rivet fastening, riveting fastening, or assembly connection.

[0028] In a battery cell stack, the battery cells can be stacked along one direction so that their faces are opposite each other.

[0029] The battery module may include a connecting busbar.

[0030] Connecting busbars can be made to at least two busbars by mechanical fastening.

[0031] Through holes can be formed in each of the busbars and connecting busbars, and bolt members can pass through the through holes of the busbars and connecting busbars and then be fastened to nut members.

[0032] Through holes can be formed in each of the busbars and connecting busbars, and rivet members can fasten the through holes of the busbars and connecting busbars.

[0033] Busbars and connecting busbars can be connected to each other by riveting.

[0034] The busbar and the connecting busbar can be configured such that an insertion slot is formed in either the busbar or the connecting busbar, and the busbar and the connecting busbar can be connected to each other while the other busbar is fitted into the insertion slot.

[0035] The connecting busbar can be a strip-shaped metal component or a metal component with a bent portion.

[0036] At least two protrusions in the battery cell can be connected to one of the busbars.

[0037] At least one busbar frame may be arranged on one or both sides of the battery cell stack, and the busbar frame may be located between the busbar and the battery cell stack.

[0038] Beneficial effects

[0039] According to embodiments of this disclosure, the resistance during the electrical connection process of a battery cell can be reduced by directly bonding the electrode current collector within the electrode to the busbar in a battery cell busbar integrated structure. Therefore, voltage measurement errors in high-output battery modules can be reduced, and heat generation in the battery cell during charging and discharging can be decreased.

[0040] Furthermore, applying mechanical fastening structures to the connections between busbars in battery modules increases design freedom. Additionally, mechanical fastening structures are easier to rework than welding and eliminate concerns about losses due to welding defects.

[0041] The effects that can be obtained from this disclosure are not limited to those described above, and other additional effects not mentioned herein will be clearly understood by those skilled in the art from the description of this disclosure. Attached Figure Description

[0042] Figure 1 This is a 3D diagram illustrating a conventional battery module.

[0043] Figure 2 It is enlarged and illustrated Figure 1 A partial image of part "A".

[0044] Figure 3 It is a cross-sectional diagram used to illustrate the connection configuration between the electrode connectors and electrode leads within the battery cells of a conventional battery module.

[0045] Figure 4 This is an exploded perspective view illustrating a battery module according to one embodiment of the present disclosure.

[0046] Figure 5 This is an example Figure 4 A plan view of one of the battery cells included in the battery module.

[0047] Figure 6 This is an example along Figure 5 A cross-sectional view of the section cut by the cutting line B-B'.

[0048] Figure 7 It is an enlarged example Figure 4 A partial 3D view of the battery cell stack and busbar section included in the battery module.

[0049] Figure 8 This is a partial perspective view used to explain the bolt fastening structure between the busbar and the connecting busbar according to one embodiment of the present disclosure.

[0050] Figure 9 This is a perspective view illustrating a busbar frame according to one embodiment of the present disclosure.

[0051] Figure 10This is a front view illustrating a busbar frame according to another embodiment of the present disclosure.

[0052] Figure 11 This is a schematic illustration of a busbar, a connecting busbar, and a busbar frame according to one embodiment of the present disclosure.

[0053] Figure 12 and Figure 13 These are cross-sectional views of battery cells according to other embodiments of this disclosure.

[0054] Figure 14 and Figure 15 This is a perspective view illustrating a rivet fastening method in a mechanical fastening method according to an embodiment of the present disclosure.

[0055] Figure 16 It is along Figure 15 The cross-sectional view taken by the cutting line C-C'.

[0056] Figure 17 This is a perspective view illustrating a riveting fastening method in a mechanical fastening method according to an embodiment of the present disclosure.

[0057] Figure 18 It is along Figure 17 The cross-sectional view taken by the cutting line D-D'.

[0058] Figure 19a and Figure 19b This is a cross-sectional view used to explain the assembly connection in the mechanical fastening method according to embodiments of the present disclosure.

[0059] Figure 20 This is a magnified partial perspective view illustrating a battery cell stack and busbar portion according to another embodiment of the present disclosure.

[0060] Explanation of reference numerals in the attached figures

[0061] 100: Battery Module

[0062] 110: Battery Cells

[0063] 110A: Electrode assembly

[0064] 111, 112: Electrodes

[0065] 111F, 112F: Electrode current collectors

[0066] 111M, 112M: Active material layer

[0067] 111P, 112P: Protrusions

[0068] 114: Bag-shaped shell

[0069] 114S: Sealing part

[0070] 120: Battery cell stack

[0071] 200: Module Framework

[0072] 300: End plate

[0073] 400: Thermopolymer layer

[0074] 500: Busbar

[0075] 500H: Through hole

[0076] 600: Connect busbar

[0077] 600H: Through hole

[0078] 710: Bolted components

[0079] 720: Nut component Detailed Implementation

[0080] In the following, various embodiments of this disclosure will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement them. This disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0081] For clarity, descriptions of parts unrelated to the specification will be omitted, and throughout the specification, the same reference numerals will denote the same or similar elements.

[0082] Furthermore, in the accompanying drawings, for ease of description, the dimensions and thicknesses of each element are arbitrarily illustrated, and this disclosure is not necessarily limited to the contents illustrated in the drawings. In the accompanying drawings, the thicknesses of layers, regions, etc., are exaggerated for clarity. In the accompanying drawings, the thicknesses of parts and regions are exaggerated for ease of description.

[0083] Furthermore, it will be understood that when an element such as a layer, membrane, region, or plate is referred to as being "on" or "above" another element, it may be directly on the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" "on" another element, it means that there are no other intermediate elements present. Additionally, "above" or "above" a specific portion to a reference portion means that the specific portion is located above or below the reference portion, and does not specifically mean that the specific portion is "above" or "above" facing the opposite direction of gravity.

[0084] Furthermore, throughout the specification, when a part is referred to as “including” or “contains” a particular component, unless otherwise stated, it means that the part may further include other components, without excluding other components.

[0085] Furthermore, throughout the instruction manual, when referred to as a "plane," it means the target portion is viewed from above, while when referred to as a "section," it means the target portion is viewed from the side of a vertically cut section.

[0086] Figure 4 This is an exploded perspective view illustrating a battery module according to one embodiment of the present disclosure. Figure 5 This is an example Figure 4 A plan view of one of the battery cells included in the battery module. Figure 6 This is an example along Figure 5 A cross-sectional view of the section cut by the cutting line B-B'.

[0087] Reference Figures 4 to 6 According to one embodiment of the present disclosure, a battery module 100 includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked. First, the battery cells 110 included in the battery cell stack 120 according to the present embodiment will be described in detail.

[0088] The battery cell 110 according to this embodiment includes: an electrode assembly 111A, the electrode assembly including electrodes 111 and 112 and a separator 110S located between electrodes 111 and 112; and a pouch-shaped housing 114, the outer periphery of which is sealed when the electrode assembly 110A is housed inside. That is, the battery cell 110 according to this embodiment is a pouch-type battery cell and may have a rectangular sheet shape.

[0089] Each of electrodes 111 and 112 includes electrode current collectors 111F and 112F, and active material layers 111M and 112M formed on one or both sides of electrode current collectors 111F and 112F. Electrodes 111 and 112 include a positive electrode 111 and a negative electrode 112. More specifically, the positive electrode 111 may include a positive electrode current collector 111F and a positive electrode active material layer 111M formed by coating a positive electrode active material onto one or both sides of the positive electrode current collector 111F, and the negative electrode 112 may include a negative electrode current collector 112F and a negative electrode active material layer 112M formed by coating a negative electrode active material onto one or both sides of the negative electrode current collector 112F. A separator 110S is inserted between the positive electrode 111 and the negative electrode 112 to prevent contact between the positive electrode 111 and the negative electrode 112.

[0090] The battery cell 110 can be formed by housing the electrode assembly 110A in a pouch-shaped housing 114 made of a laminate including resin layers and metal layers, and then bonding the outer periphery of the pouch-shaped housing 114. Specifically, the battery cell 110 can be produced by bonding the two ends 114a and 114b of the pouch-shaped housing and one side 114c connecting them while the electrode assembly 110A is housed in the pouch-shaped housing 114. In other words, the battery cell 110 according to one embodiment of the present disclosure has a total of three sealing portions 114S, wherein the sealing portions 114S have a structure sealed by bonding between the internal resin layers, which will be described later, and the remaining side portion can be formed by a folded portion 115.

[0091] The pouch-like housing 114 of the laminate may include an inner resin layer for sealing, a metal layer to prevent material penetration, and an outermost resin layer. Based on the electrode assembly within the pouch-like housing 114, the inner resin layer may be located on the innermost side, the outer resin layer may be located on the outermost side, and the metal layer may be located between the inner and outer resin layers.

[0092] The outer resin layer exhibits excellent tensile strength and weather resistance relative to its thickness, and may possess electrical insulation properties to protect the electrode assembly from external influences. This outer resin layer may comprise polyethylene terephthalate (PET) resin or nylon resin. A metal layer prevents air, moisture, etc., from entering the pouch cell. Such a metal layer may comprise aluminum (Al). The inner resin layers can be thermally welded together by applying heat and / or pressure while the electrode assembly is embedded therein. This inner resin layer may comprise cast polypropylene (CPP) or polypropylene (PP).

[0093] The pouch-shaped housing 114 is divided into two parts, and a concave receiving portion in at least one of the two parts can be formed therein, in which an electrode assembly can be placed. Along the outer periphery of this receiving portion, the inner resin layers of the two parts of the pouch-shaped housing 114 can be joined together to provide a seal 114S. Heat and / or pressure can be applied to bond the inner resin layers together. By sealing the pouch-shaped housing 114 in this way, a pouch-type battery cell 110 can be produced.

[0094] Multiple battery cells 110 are configured, and these cells 110 are stacked so that they can be electrically connected to each other, thereby forming a battery cell stack 120. Specifically, as... Figure 4 As shown, multiple battery cells 110 can be stacked upright in a direction parallel to the y-axis, such that the cell body 113 (see...) Figure 5 They faced each other on one side.

[0095] Furthermore, the electrode current collectors 111F and 112F according to this embodiment include protrusions 111P and 112P formed such that a portion of the electrode current collectors 111F and 112F protrudes to the outside of the sealed bag-shaped housing 114. That is, a portion of the electrode current collectors 111F and 112F extends to form protrusions 111P and 112P, and such protrusions 111P and 112P can protrude beyond the sealing portion 114S of the bag-shaped housing 114 to the outside.

[0096] exist Figure 6 In this example, only a portion of the positive current collector 111F is shown as a protrusion 111P formed by extending that portion, but a portion of the negative current collector 112F can extend in the opposite direction to form a protrusion 112P. Therefore, as... Figure 5 As shown, the protrusion 111P extending from the positive current collector 111F in the battery cell 110 can protrude in the x-axis direction, and the protrusion 112P extending from the negative current collector 112F can protrude in the -x-axis direction.

[0097] Busbar 500 is joined to protrusions 111P and 112P. Specifically, protrusions 111P and 112P and busbar 500 can be welded together. That is, in the case of battery cell 110 according to this embodiment, protrusions 111P and 112P formed by extending electrode current collectors 111F and 112F can be directly joined to busbar 500, thereby forming a battery cell busbar integrated structure. In particular, with protrusions 111P and 112P extending from electrode current collectors 111F and 112F joined to busbar 500, electrode assembly 110A can be housed in pouch-shaped housing 114, and the outer periphery of pouch-shaped housing 114 can be sealed to form sealing portions 114S. To improve sealing performance and ensure electrical insulation, a membrane 114F surrounding protrusions 111P and 112P can be inserted between sealing portions 114S. This membrane 114F is a material with electrical insulation and bonding properties, and may include one or more materials selected from the group consisting of polyimide (PI), polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET).

[0098] Unlike conventional battery cells 11 that use electrode leads 11L, the battery cell 110 according to this embodiment minimizes the area for performing welding by directly joining protrusions 111P and 112P formed by extending electrode current collectors 111F and 112F to the busbar 500. In other words, by eliminating the electrode leads 11L, welding resistance during the process of achieving electrical connections between the battery cells 110 included in the battery module 100 can be reduced. By reducing internal resistance, voltage measurement errors in the high-output battery module 100 can be reduced, and the heat generated by the battery cells 110 during charging and discharging can be reduced.

[0099] Next, the structure of the busbar and connecting busbar according to this embodiment will be described in detail.

[0100] Figure 7 It is an enlarged example Figure 4 A partial 3D view of the battery cell stack and busbar section included in the battery module. Figure 8 This is a partial perspective view used to explain the bolt fastening structure between the busbar and the connecting busbar according to one embodiment of the present disclosure.

[0101] Refer to together Figure 4 and Figures 6 to 8 The battery module 100 according to this embodiment includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked, wherein busbars 500 are connected to each other using a mechanical fastening method to perform electrical connection between the battery cells 110. Here, mechanical fastening method refers to a fastening method using physical constraint force, rather than a method using welding, adhesives, etc. The mechanical fastening method used in this disclosure is not particularly limited, as long as electrical connection between the busbars 500 is possible.

[0102] For example, the mechanical fastening method according to this embodiment can be bolt fastening, rivet fastening, riveting fastening, or assembly connection. First, as an example of the mechanical fastening method of this disclosure, a bolt fastening method will be described.

[0103] As described above, in the battery cell stack 120, the battery cells 110 can be stacked along one direction so that their faces are opposite each other. Figure 4 An example is illustrated where multiple battery cells 110 are stacked upright in a direction parallel to the y-axis, such that the cell body 113 (see [reference]) Figure 5 A state in which they face each other.

[0104] At this point, as described above, the busbar 500 engages with the protrusions 111P and 112P to form a battery cell busbar integrated structure. The battery module 100 may also include a connecting busbar 600 connecting the busbar 500. Both the busbar 500 and the connecting busbar 600 may be made of a highly conductive metallic material.

[0105] The connecting busbar 600 can be connected to at least two busbars 500 by a mechanical fastening method. As an example of a mechanical fastening method, the connecting busbar 600 can be connected to at least two busbars 500 by bolt fastening. For example, a through hole 500H can be formed in the busbar 500, and a through hole 600H can also be formed in the connecting busbar 600. A bolt member 710 passes through the through hole 500H of the busbar 500 and the through hole 600H of the connecting busbar 600, and can then be fastened to a nut member 720.

[0106] Since the battery cell 110 according to this embodiment has an integrated structure in which the busbar 500 is already connected to the battery cell 110, a bolt-fastening structure using the busbar 600 is applied to the electrical connection between the battery cells 110. Compared with conventional battery modules where welding is performed between the electrode leads 11L and the busbar 40, the bolt-fastening structure using the busbar 600 has the advantage of increasing the degree of freedom in designing the battery module 100. (Referring later...) Figure 11 This is described. Furthermore, bolted fastening is easier to rework than welding, and there is no need to worry about losses due to welding defects between the electrode lead 11L and the busbar 40. (Refer to...) Figures 14 to 19b Further examples of mechanical fastening methods will be described.

[0107] Figure 9 This is a perspective view illustrating a busbar frame according to one embodiment of the present disclosure.

[0108] Refer to together Figure 7 and Figure 9 The battery module according to this embodiment may further include at least one busbar frame 800 disposed on one or both sides of the battery cell stack 120. Figure 7 For ease of explanation, only busbar 500 is shown in the diagram, but busbar frame 800 may be located between battery cell stack 120 and busbar 500.

[0109] Specifically, the busbar 500 is located on one side of the busbar frame 800, and the battery cell stack 120 can face the other surface of the busbar frame 800. The protrusions 111P and 112P of the battery cell 110 can pass through the slits 800S formed in the busbar frame 800.

[0110] Figure 10 This is a front view illustrating a busbar frame according to another embodiment of the present disclosure.

[0111] Refer to together Figure 7 and Figure 10 Similar to Figure 9 The busbar frame 800, according to another embodiment of the present disclosure, may have a slit 800S' through which the protrusions 111P and 112P of the battery cell 110 can pass. The busbar 500 is located on one side of such busbar frame 800', and the other side of busbar frame 800' can face the battery cell stack 120.

[0112] At this time, since the protrusions 111P and 112P according to this embodiment have already been joined to the busbar 500, the slit 800S' formed in the busbar frame 800' according to this embodiment can be a slit opening towards the upper or lower side of the busbar frame 800, so that the protrusions 111P and 112P can be fitted into the slit 800S. For example, Figure 10 An example is shown of a slit 800S' with an opening on the lower side of the busbar frame 800. A protrusion 111P, already attached to the busbar 500, can be inserted into the slit 800S' through the lower part of the opening. Therefore, the busbar 500 is located on one side of the busbar frame 800', and the other side of the busbar frame 800' can face the battery cell stack 120.

[0113] Furthermore, busbar frames 800 and 800' may include electrically insulating materials. For example, busbar frames 800 and 800' may include electrically insulating plastic materials. Busbar frames 800 and 800' are components arranged to prevent short circuits from occurring between the busbar 500 and the battery cell 110.

[0114] Although not specifically illustrated, the busbar frame 800 may be equipped with terminal busbars that serve as external input / output terminals and sensing components that transmit temperature and voltage information of the battery cells.

[0115] Figure 11 This is a schematic illustration of a busbar, a connecting busbar, and a busbar frame according to one embodiment of the present disclosure.

[0116] exist Figure 11 The diagram schematically illustrates the appearance of the busbar 500 located on one side of the busbar frame 800, as well as the appearance of the connecting busbars 600a, 600b and 600c connected to the busbar 500.

[0117] The connecting busbars 600a, 600b, and 600c according to this embodiment can have various shapes. For example, the connecting busbars 600a, 600b, and 600c can be strip-shaped metal components or metal components with bent portions. The lengths of the connecting busbars 600a and 600b, which are strip-shaped metal components, can be adjusted in various ways. Furthermore, the connecting busbar 600c can be freely provided with bent portions.

[0118] In this way, the busbar 500 can be connected by applying connecting busbars 600a, 600b, and 600c with various shapes and sizes. Therefore, the position and number of battery cells with the busbar 500 can be freely and unrestricted. In other words, the advantage of using the mechanical fastening method of the connecting busbar 600 is that it increases the degree of freedom in designing the electrical connection method of the battery cells included in the battery module 100.

[0119] Figure 12 and Figure 13 These are cross-sectional views of battery cells according to other embodiments of this disclosure.

[0120] First, refer to Figure 12 Similar to the aforementioned embodiment, in the battery cell 110, the electrode leads are removed, and the protrusion 111P extending from the electrode current collector 111F is joined to the busbar 500. Additionally, to improve sealing performance and ensure electrical insulation, a membrane 114F' surrounding the protrusions 111P and 112P can be inserted between the sealing portions 114S.

[0121] Compared to the removed electrode leads, the protrusion 111P extending from the electrode current collector 111F has relatively weak rigidity and is therefore easily damaged by external impacts or vibrations. To compensate for the rigidity of the protrusion 111P, the membrane 114F' according to this embodiment may surround the region where the protrusion 111P extends, in order to engage with the busbar 500. In other words, the membrane 114F' according to this embodiment may surround the portion where the protrusion 111P is exposed to the outside of the sealing portion 114S of the bag-shaped housing 114.

[0122] Reference Figure 13According to another embodiment of this disclosure, the membrane 114F” can extend not only around the area where the protrusion 111P is engaged with the busbar 500, but also around the portion where the protrusion 111P is engaged with the busbar 500 and at least a portion of the busbar 500. This allows for the reinforcement of the rigidity not only of the portion where the protrusion 111P is exposed to the outside of the sealing portion 114S of the bag-shaped housing 114, but also of the rigidity of the portion where the protrusion 111P and the busbar 500 are engaged. Furthermore, this membrane 114F” can increase electrical insulation by preventing the protrusion 111P or the busbar 500 from contacting other portions. Conversely, the portion of the busbar 500 connected to the connecting busbar 600 may not be covered by the membrane 114F” to facilitate bolt fastening between the busbar 500 and the connecting busbar 600.

[0123] In addition, refer to again Figure 4 The battery module 100 according to this embodiment may further include a module frame 200 in which a battery cell stack 120 is housed. The module frame 200 is a component that houses the battery cell stack 120 and may include two side surface portions 210 and 220, an upper surface portion 230, and a lower surface portion 240. Furthermore, the module frame 200 may have openings on two sides corresponding to the x-axis direction and its opposite direction. The battery cell stack 120 can be housed through either of the two open sides. The module frame 200 may include a metallic material with a predetermined strength to protect internal electrical components.

[0124] Figure 4 The illustrated module frame 200 can be a single frame having a structure in which two side surface portions 210 and 220, an upper surface portion 230, and a lower surface portion 240 are integrated. Although not specifically illustrated, in other embodiments of this disclosure, a module frame in which a U-shaped frame and an upper plate are welded together is also possible. Viewed from the stacking direction of the module frame 200 and the battery cell 110, the battery cell 110 can be stacked from one side surface 210 to the other side surface 220, such that one side of the battery cell 110, particularly the cell body 113 (see...), is... Figure 5 One side of the module frame 200, parallel to the side surface portions 210 and 220 of the module frame 200.

[0125] Furthermore, the battery module 100 according to this embodiment may also include end plates 300 located on two open sides of the module frame 200. The end plates 300 may be positioned to cover the battery cell stack 120 on the two open sides of the module frame 200. The edge of each end plate 300 may be joined to the corresponding edge of the module frame 200 by welding. The end plates 300 may include a metallic material with a predetermined strength and may protect the battery cell stack 120 and other electrical components from external impacts. (See the above-described busbar frame 800). Figure 9 It can be located between the end plate 300 and the battery cell stack 120.

[0126] The battery module 100 may further include a thermal resin layer 400 located between the battery cell stack 120 and the lower surface portion 240 of the module frame 200. One side of the battery cell 110 may be bonded to the thermal resin layer 400. Specifically, the thermal resin layer 400 may be formed by injecting or coating a thermal resin and then allowing it to cure. The thermal resin may include a thermally conductive adhesive material, and specifically may include at least one of a silicone resin material, a polyurethane material, or an acrylic material. The thermal resin may be in a liquid state when coated, but may cure after coating and bond to one side of the battery cell 110. Thus, the thermal resin layer 400 can be used to fix the battery cell 110. In addition, the thermal resin layer 400 has excellent thermal conductivity and is able to quickly transfer the heat generated in the battery cell 110 to the lower side of the battery module.

[0127] Next, in the mechanical fastening methods disclosed herein, other examples of alternatives to bolt fastening methods will be described.

[0128] Figure 14 and Figure 15 This is a perspective view illustrating a rivet fastening method in a mechanical fastening method according to an embodiment of the present disclosure. Specifically, Figure 14 This is a diagram illustrating the rivet component before it is inserted, and Figure 15 This is an example of what happens after the rivet components have been inserted and tightened. Figure 16 It is along Figure 15 The cross-sectional view taken by the cutting line C-C'.

[0129] Reference Figures 14 to 16 Rivet fastening can be applied to the mechanical fastening between busbars 500. An example of the rivet fastening method will be described below.

[0130] As previously described, the battery cell 110 may have a protrusion 111P that passes through the sealing portion 114S and engages with the busbar 500. A through hole 500H may be formed in the busbar 500, and the rivet member 900 may fasten the through hole 500H of the busbar 500 and the through hole 600H connecting the busbar 600.

[0131] Before being fastened, the rivet component 900 has a first end 910 and a second end 920 with different diameters. The diameter of the first end 910, which has a relatively larger diameter, is greater than the diameter of the through hole 500H of the busbar 500 and the through hole 600H connecting the busbar 600. Conversely, the diameter of the second end 920, which has a relatively smaller diameter, is smaller than the diameter of the through hole 500H of the busbar 500 and the through hole 600H connecting the busbar 600. The second end 920 can pass through both the through hole 500H of the busbar 500 and the through hole 600H connecting the busbar 600.

[0132] After passing through the hole, force is applied to the second end 920 to deform its shape. The first end 910 does not deform but retains its shape. The deformed second end 920' appears as follows: Figure 15 and Figure 16 As illustrated in the example. The deformed second end 920' can be deformed similarly to the first end 910. That is, the diameter of the deformed second end 920' can be larger than the diameter of the through hole 500H of the busbar 500 and the diameter of the through hole 600H of the connecting busbar 600. With the rivet member 900 passing through the through hole 500H of the busbar 500 and the through hole 600H of the connecting busbar 600, rivet fastening can be achieved by deforming the shape of the second end 920. The busbar 500 and the connecting busbar 600 can be electrically connected to each other while being tightly fitted and fixed by the rivet member 900.

[0133] Figure 17 This is a perspective view illustrating a riveting fastening method in a mechanical fastening method according to an embodiment of the present disclosure. Figure 18 It is along Figure 17 The cross-sectional view taken by the cutting line D-D'.

[0134] Reference Figure 17 and Figure 18 Riveting fasteners can be applied to the mechanical fastening between busbars 500. An example of a riveting fastener will be described below.

[0135] As previously described, the battery cell 110 may have a protrusion 111P that passes through the sealing portion 114S and engages with the busbar 500. The busbar 500 and the connecting busbar 600 may be connected to each other by riveting.

[0136] Specifically, a punch and a die can be used to perform the pressing operation while the busbar 500 and the connecting busbar 600 are in contact with each other. With the busbar 500 and the connecting busbar 600 supported by the die, a riveting hole (CH) can be formed while the punch presses down on the overlapping portion of the busbar 500 and the connecting busbar 600. At this time, an interlocking structure (IL) can be formed according to the shape of the die. The interlocking structure (IL) generates a bonding force by utilizing the plastic deformation of the material and its flow in opposite directions, thereby electrically connecting the busbar 500 and the connecting busbar 600 to each other while ensuring tight adhesion and fixation.

[0137] Figure 19a and Figure 19b This is a cross-sectional view used to explain the assembly connection in the mechanical fastening method according to embodiments of the present disclosure. Figure 19a The example illustrates the busbar and connecting busbar before connection, and Figure 19b This example illustrates the situation after the busbar and connecting busbar are connected.

[0138] Reference Figure 19a and Figure 19b Assembly connectors can be used for mechanical fastening between busbars 500. For example, an insertion slot 600G can be formed in either busbar 500 or connecting busbar 600, and the other of busbar 500 and connecting busbar 600 can be assembled into the insertion slot 600G so that busbar 500 and connecting busbar 600 can be connected to each other. Figure 19a and Figure 19b An example is shown where an insertion slot 600G is formed in a connecting busbar 600.

[0139] Furthermore, an insertion slot 600G can be formed between the first portion 610 and the second portion 620 of the connecting busbar 600, and the first portion 610 and the second portion 620 can have a shape that bends towards each other. When the busbar 500 is inserted between the first portion 610 and the second portion 620, the first portion 610 and the second portion 620 act like leaf springs, allowing the busbar 500 to be fixed by the elastic force of the first portion 610 and the second portion 620. Thus, the busbar 500 and the connecting busbar 600 can be electrically connected to each other while being tightly fitted and fixed. Although not specifically illustrated, it is also possible to have an embodiment of this disclosure in which an insertion slot is formed in the busbar and the connecting busbar is inserted into the insertion slot of the busbar.

[0140] Figure 20 This is a magnified partial perspective view illustrating a battery cell stack and busbar portion according to another embodiment of the present disclosure.

[0141] Reference Figure 20In another embodiment of the battery cell stack 120 according to this disclosure, the protrusions 111P of at least two battery cells 110 can be joined to a busbar 500'. The protrusions 111P protruding from the battery cells 110 are directly connected to the busbar 500', wherein multiple protrusions 111P of the battery cells 110 can be joined to a busbar 500'. For this purpose, the busbar 500' can extend further along the direction in which the battery cells 110 are stacked, and the busbar 500' can be formed with slits. For example, Figure 20 An example is shown where the protrusions 111P of four or five battery cells 110 are joined to a busbar 500'. By simply joining the multiple protrusions 111P to a busbar 500, multiple battery cells 110 can be electrically connected easily. That is, this embodiment has the advantage that contact resistance can be reduced because separate connections between busbars are not required.

[0142] In this embodiment, terms such as front, back, left, right, top, and bottom have been used to indicate directions. However, it will be apparent to those skilled in the art that the terms used are provided merely for ease of description and may vary depending on the position of the object, the position of the observer, etc.

[0143] One or more battery modules according to embodiments of this disclosure can be installed together with various control and protection systems such as BMS (Battery Management System), BDU (Battery Disconnect Unit), and cooling system to form a battery pack.

[0144] Battery modules or battery packs can be applied to a variety of devices. Specifically, they can be applied to vehicle devices such as electric bicycles, electric vehicles, and hybrid vehicles, or ESS (energy storage systems), but are not limited to these, and can be applied to a variety of devices that can use rechargeable batteries.

[0145] Although the present invention has been described in detail with reference to preferred embodiments thereof, the scope of the present disclosure is not limited thereto, and those skilled in the art can make various modifications and improvements using the basic concept of the present disclosure as defined in the appended claims and falling within the scope of the present disclosure.

Claims

1. A battery cell, characterized in that, The battery cell includes: An electrode assembly, the electrode assembly including electrodes and a diaphragm located between the electrodes; and A bag-shaped housing, the outer periphery of which is sealed while the electrode assembly is housed within the bag-shaped housing. The electrode includes an electrode current collector and an active material layer formed on one or both sides of the electrode current collector. The electrode current collector includes a protrusion formed such that a portion of the electrode current collector protrudes outside the sealed bag-shaped housing. The busbar is connected to the protrusion.

2. The battery cell according to claim 1, characterized in that, The protrusion is welded to the busbar.

3. The battery cell according to claim 1, characterized in that, The outer periphery of the bag-shaped housing is sealed while the protrusion is engaged with the manifold.

4. The battery cell according to claim 1, characterized in that, The outer periphery of the bag-shaped shell is sealed to form a sealing portion, and A membrane surrounding the protrusion is inserted between the sealing portions.

5. The battery cell according to claim 4, characterized in that, The membrane surrounds the protrusion until the portion of the protrusion exposed to the outside of the seal.

6. The battery cell according to claim 4, characterized in that, The membrane surrounds the portion of the protrusion that engages with the busbar and at least a portion of the busbar.

7. A battery module, characterized by The battery module includes: A battery cell stack, wherein the battery cells according to claim 1 are stacked in the battery cell stack. The busbars are mechanically fastened together to enable electrical connections between the battery cells.

8. The battery module according to claim 7, characterized in that, The mechanical fastening refers to bolt fastening, rivet fastening, riveting fastening, or assembly connection.

9. The battery module according to claim 7, characterized in that, In the battery cell stack, the battery cells are stacked along one direction so that their faces are opposite each other.

10. The battery module according to claim 7, characterized in that, The battery module includes a connecting busbar that connects to the busbar.

11. The battery module according to claim 10, characterized in that, The connecting busbar is connected to at least two of the busbars by the mechanical fastening.

12. The battery module according to claim 11, characterized in that, A through hole is formed in each of the busbars and the connecting busbars, and The bolt member passes through the through hole of the busbar and the through hole of the connecting busbar and is then fastened to the nut member.

13. The battery module according to claim 11, characterized in that, A through hole is formed in each of the busbars and the connecting busbars, and The rivet component fastens the through hole of the busbar and the through hole connecting the busbar.

14. The battery module according to claim 11, characterized in that, The busbar and the connecting busbar are connected to each other by riveting.

15. The battery module according to claim 11, characterized in that, The busbar and the connecting busbar are configured such that an insertion slot is formed in either the busbar or the connecting busbar, and When the other of the busbar and the connecting busbar is fitted into the insertion slot, the busbar and the connecting busbar are connected to each other.

16. The battery module according to claim 11, characterized in that, The connecting busbar is a strip-shaped metal component or a metal component with a bent portion.

17. The battery module according to claim 7, characterized in that, The protrusions of at least two of the battery cells are engaged with one of the busbars.

18. The battery module according to claim 7, characterized in that, At least one busbar frame is arranged on one or both sides of the cell stack, and The busbar frame is located between the busbar and the cell stack.

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