Busbar frame assembly and battery module including same

Abstract

A busbar frame assembly according to an embodiment of the present invention comprises: a busbar connected to electrode leads of a plurality of battery cells; and a welding plate on which the busbar and a welding portion are formed, wherein the busbar includes a plurality of protrusions, the welding plate includes fastening holes into which the protrusions are inserted, and the welding portion is located between the plurality of protrusions.

Description

Busbar frame assembly and battery module including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0132602 filed September 30, 2024, and all contents disclosed in the literature of said Korean patent applications are incorporated herein as part of this specification.

[0003] The present invention relates to a busbar frame assembly and a battery module including the same, and more specifically, to a busbar frame assembly and a battery module including the same having improved mechanical rigidity and electrical connection stability.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0006] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0007] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0008] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a stack of battery cells. In addition, one or more battery modules can be mounted together with various control and protection systems, such as a Battery Disconnect Unit (BDU), a Battery Management System (BMS), and a cooling system, to form a battery pack.

[0009] FIG. 1 is a perspective view showing a conventional battery module (10). FIG. 2 is a plan view showing a conventional busbar frame assembly (14). FIG. 3 is a partial view showing an enlarged view of the “X” portion of FIG. 2. FIG. 4 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of FIG. 3.

[0010] In order to sense information of each battery cell (11) in a conventional battery module (10), the sequence of electrode leads (12) of the battery cell (11), busbar (15), flexible printed circuit board (FLEXIBLE PRINTED CIRCUIT, FPC, 16), and connector (not shown) must be followed. To do this, a separate welding plate (17) must be added, and the welding plate (17) and the flexible printed circuit board (16) must be joined through a crimping process, and the welding plate (17) and the busbar (15) must be joined through a welding process.

[0011] However, if the welding plate (17) and the busbar (15) are not stably fixed, a problem arises in which the contact resistance and bonding strength decrease. Accordingly, research is being continued to ensure a stable connection between the welding plate (17) and the busbar (15).

[0012] The problem that the present invention aims to solve is to secure mechanical rigidity and electrical connection stability between a busbar and a welding plate, and to provide a busbar frame assembly with improved mechanical rigidity and electrical connection stability and a battery module including the same.

[0013] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0014] A busbar frame assembly according to one embodiment of the present invention comprises: a busbar connected to electrode leads of a plurality of battery cells; and a welding plate having a weld formed thereon with the busbar; wherein the busbar includes a plurality of protrusions, the welding plate includes a fastening hole into which the protrusions are inserted, and the weld is located between the plurality of protrusions.

[0015] In one embodiment, the protrusion and the fastening hole may be joined by soldering.

[0016] In one embodiment, the soldering joint and the weld may be formed by the same heat source.

[0017] In one embodiment, the soldering joint and the weld may be formed simultaneously.

[0018] In one embodiment, the soldering connection may physically connect the protrusion and the fastening hole.

[0019] In one embodiment, the protrusion may include a first protrusion and a second protrusion facing each other with the welded portion in between.

[0020] In one embodiment, the weld may include a first weld adjacent to the first protrusion and a second weld adjacent to the second protrusion.

[0021] In one embodiment, the fastening hole may be formed to correspond to the shape of the protrusion.

[0022] In one embodiment, a printed circuit board (PCB) for voltage sensing of the battery cells is further included, and the printed circuit board may be connected in contact with the welding plate.

[0023] In one embodiment, the welding plate may be plate-shaped.

[0024] In one embodiment, the busbar frame equipped with the busbar and the welding plate may be further included.

[0025] In one embodiment, the busbar and the welding plate may be mounted on the opposite side of the busbar frame facing the battery cells.

[0026] A battery module according to one embodiment of the present invention includes a busbar frame assembly according to at least one of the above.

[0027] According to embodiments of the present invention, electrical stability and mechanical rigidity can be secured by additionally soldering the busbar and the welding plate in addition to the connection of the protrusion and the fastening hole.

[0028] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0029] FIG. 1 is a perspective view showing a conventional battery module.

[0030] FIG. 2 is a plan view showing a conventional busbar frame assembly.

[0031] Figure 3 is a partial drawing showing an enlarged view of the "X" portion of Figure 2.

[0032] Figure 4 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 3.

[0033] FIG. 5 is a perspective view showing a battery module according to one embodiment of the present invention.

[0034] FIG. 6 is a plan view showing a busbar frame assembly according to one embodiment of the present invention.

[0035] Figure 7 is a partial drawing showing an enlarged view of the "Y" portion of Figure 6.

[0036] Figure 8 is a cross-sectional view showing the cross-section of a busbar cut along the cutting line B-B' of Figure 7.

[0037] Figure 9 is a cross-sectional view showing the cross-section of a welding plate cut along the cutting line B-B' of Figure 7.

[0038] Figure 10 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of Figure 7.

[0039] Figure 11 is a cross-sectional view showing a cross-section cut along the cutting line C-C' of Figure 5.

[0040] Hereinafter, various 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. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0041] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0042] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0043] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0044] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0045] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0046] FIG. 5 is a perspective view showing a battery module according to an embodiment of the present invention. FIG. 6 is a plan view showing a busbar frame assembly (150) according to an embodiment of the present invention. FIG. 7 is a partial view showing an enlarged view of the "Y" portion of FIG. 6.

[0047] Referring to FIGS. 5 to 7, a busbar frame assembly (150) according to one embodiment of the present invention comprises: a busbar (152) connected to electrode leads (111) of a plurality of battery cells (110); a printed circuit board (153, Printed Circuit Board, PCB) for voltage sensing of the battery cells (110); and a welding plate (154) connecting the busbar (152) and the printed circuit board (153). The welding plate (154) electrically connects the busbar (152) and the printed circuit board (153).

[0048] For example, the battery cell (110) is illustrated as being a pouch-type battery cell (110). The pouch-type battery cell (110) can be formed by housing an electrode assembly in a pouch case of a laminate sheet comprising a resin layer and a metal layer, and then heat-sealing the sealing portion of the pouch case. At this time, the battery cell (110) can be formed in a rectangular sheet-type structure. However, the battery cell (110) of the present invention is not limited to a pouch type.

[0049] In a battery cell stack (120), a plurality of battery cells (110) can be stacked in one direction. For example, as shown in FIG. 5, a plurality of battery cells (110) can be stacked along the X-axis direction while standing upright so that one side of the battery body faces each other. Accordingly, electrode leads (111) can protrude in a direction perpendicular to the direction in which the battery cells (110) are stacked. For example, in a battery cell (110), one electrode lead (111) can protrude toward the Y-axis direction, and another electrode lead (111) can protrude toward the -Y-axis direction.

[0050] The battery module (100) according to the present embodiment may include a module frame (130) that accommodates a battery cell stack (120) and end plates (180) that cover the front and rear sides of the battery cell stack (120), respectively. Here, the front and rear sides of the battery cell stack (120) may be the two sides of the battery cell stack (120) in the direction in which electrode leads (111) protrude from the battery cell (110). In other words, the battery module (100) according to the present embodiment includes a module frame (130) in which the battery cell stack (120) is accommodated and one side in the direction in which electrode leads (111) protrude from the battery cell stack (120) is open, and an end plate (180) that covers the open side of the module frame (130). Additionally, as shown in FIG. 5, the module frame (130) can be opened in both directions, in the Y-axis direction and the -Y-axis direction, in which the electrode lead (111) protrudes, and two end plates (180) can each cover the two open directions of the module frame (130).

[0051] Additionally, as illustrated in FIG. 5, a module frame (130) according to one embodiment of the present invention may include a U-shaped frame (130a) with an open top surface, front surface, and rear surface, and a top plate (130b) covering the top of a battery cell stack (120). However, the module frame (130) is not limited thereto and may be replaced with a frame of other shapes, such as an L-shaped frame or a mono frame that surrounds the battery cell stack (120) excluding the front and rear surfaces. That is, the module frame (130) may be formed as a single module frame (130) that is not separated into a U-shaped frame and a top plate.

[0052] According to the present embodiment, the battery module (100) may include a module frame cover (140) that covers the upper part of the module frame (130).

[0053] End plates (180) can cover an open side of the module frame (130). End plates (180) can be located on the front and rear of the battery cell stack (120). End plates (180) can be formed on the outer edge of the busbar frame assembly (150) relative to the battery cell stack (120) to cover the battery cell stack (120) and the busbar frame assembly (150). The end plates (180) protect the busbar frame assembly (150) and various electrical components connected thereto from external impact and may have a battery module mounting structure. The end plates (180) can be joined to the module frame (130) through welding.

[0054] According to the present embodiment, busbar frame assemblies (150) may be formed to cover a battery cell stack (120) by being located on the open first side (Y-axis direction of FIG. 1) and the second side (-Y-axis direction of FIG. 1) of the module frame (130). The busbar frame assemblies (150) may electrically connect the battery cells (110) constituting the battery cell stack (120) in series or in parallel.

[0055] According to the present embodiment, the electrode leads (111) connected to the electrode assembly protrude outside the pouch case, and the electrode leads (111) of each battery cell can be electrically connected to each other via a busbar (152). The busbar (152) is configured to guide the electrical connection of the battery module (100), and it is sufficient to include a metal material with excellent electrical conductivity, and is not limited to its shape or material.

[0056] According to the present embodiment, the printed circuit board (153) is configured to sense voltage data or thermal data of the battery cells (110). Accordingly, the voltage data of each battery cell (110) can be sensed and transmitted to the outside.

[0057] The busbar (152) and the printed circuit board (153) are electrically connected by a welding plate (154).

[0058] Referring to FIG. 7, one end of the welding plate (154) is connected to the bus bar (152), and the other end is connected to the printed circuit board (153). In one embodiment, the welding plate (154) and the printed circuit board (153) can be joined through a crimping process. Between the welding plate (154) and the bus bar (152), there is a connection by a protrusion (160) and a connection by a weld (162).

[0059] With reference to FIGS. 8 to 10, the connection between the welding plate (154) and the bus bar (152) will be described in detail.

[0060] FIG. 8 is a cross-sectional view showing a cross- section of a busbar cut along the cutting line B-B' of FIG. 7. FIG. 9 is a cross-sectional view showing a cross-section of a welding plate cut along the cutting line B-B' of FIG. 7. FIG. 10 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of FIG. 7.

[0061] Referring to FIGS. 8 to 10 together, a protrusion (160) is formed on the bus bar (152). The protrusion (160) protrudes along the Z-axis direction, which is the upward direction, from the surface of the bus bar (152). In FIG. 8, the protrusion (160) is shown as having a square shape, but it is not limited to a circular shape or a triangular shape and can be modified.

[0062] The protrusions (160) may be provided in multiple numbers, for example, may include a first protrusion (160a) and a second protrusion (160b) facing each other with respect to the Y-axis. However, they are not limited thereto, and three or more protrusions (160) may be provided and arranged to face each other with respect to the Y-axis.

[0063] The protrusion (160) is inserted into the fastening hole (161) of the welding plate (154) that is laminated on the upper part of the bus bar (152). The thickness of the protrusion (160) may be formed to be thicker than the thickness of the welding plate (154) in order to penetrate the welding plate (154).

[0064] In one embodiment, the welding plate (154) may be provided in a plate shape. The welding plate (154) is provided on the bus bar (152) and welded to the bus bar (152). Additionally, the welding plate (154) of the present invention has a fastening hole (161) formed therein for connection with the protrusion (160). The shape of the fastening hole (161) may be formed to correspond to the shape of the protrusion (160).

[0065] As the protrusion (160) is inserted into the fastening hole (161), the bus bar (152) and the welding plate (154) can be physically joined. The fastening holes (161) are provided in the same number as the protrusion (160). In FIG. 9, as an example, the fastening holes (161) are provided in multiple numbers and are shown to include a first fastening hole (161a) and a second fastening hole (161b) facing each other with respect to the Y-axis. In addition, the connection between the protrusion (160) and the fastening hole (161) can serve as a guide to stably fix the position during welding before welding the bus bar (152) and the welding plate (154).

[0066] Meanwhile, as illustrated in FIG. 8, before the welding plate (154) is attached to the bus bar (152), soldering paste is provided on the protrusion (160). Specifically, after providing solder paste on the protrusion (160) of the bus bar (152), the welding plate (154) is laminated onto the bus bar (152) and the protrusion (160) is inserted into the fastening hole (161), and then the welding process between the bus bar (152) and the welding plate (154) is carried out. The welding can be performed, for example, by irradiating a laser. At this time, the solder paste is heated by the welding heat generated, thereby forming a soldering part (170) that stably fixes the protrusion (160) and the fastening hole (161). That is, the bus bar (152) and the welding plate (154) are formed by the same heat source called welding heat, and the welded part (162) and the soldering part (170) are formed simultaneously through the welding process.

[0067] A weld (162) is formed between a first protrusion (160a) and a second protrusion (160b) with respect to the Y-axis direction. The weld (162) may include a first weld (162a) adjacent to the first protrusion (160a) and a second weld (162b) adjacent to the second protrusion (160b). Each of the first weld (162a) and the second weld (162b) may have a shape that extends along the X-axis direction.

[0068] In the present invention, in addition to the weld (162), a soldering portion (170) exists between the busbar (152) and the welding plate (154), thereby ensuring electrical stability by adding an electrical connection path in addition to direct contact. Furthermore, as the protrusion (160) and the fastening hole (161) are soldered together, the busbar (152) and the welding plate (154) are physically fixed, so mechanical rigidity can be ensured even when the busbar frame assembly (150) is subjected to vibration or shock.

[0069]

[0070] Referring again to FIGS. 5 and FIGS. 6, a busbar frame assembly (150) according to one embodiment of the present invention may further include a busbar frame (151) on which a busbar (152), a welding plate (154), and a printed circuit board (153) are mounted.

[0071] To electrically connect multiple battery cells (110), a busbar (152) that electrically connects the electrode leads (111) of the battery cells (110) can be mounted on a busbar frame (151).

[0072] The busbar frame (151) may be a component for preventing a short circuit from occurring when the electrode lead (111) and the busbar (152) come into contact with other parts of the battery cell (110). The busbar frame (151) may include a material that is electrically insulating.

[0073] Figure 11 is a cross-sectional view showing a cross-section cut along the cutting line C-C' of Figure 5.

[0074] Referring to FIG. 11, a busbar (152), a welding plate (154), and a printed circuit board (153) may be mounted on the opposite side of the busbar frame (151) that faces the battery cells (110). Specifically, at least one busbar (152) may be mounted on one side of the busbar frame (151), and the other side of the busbar frame (151) may face the battery cells (110).

[0075] The electrode lead (111) can be connected to the busbar (152) after passing through a slit formed in the busbar frame (151). By positioning the busbar frame (151) between the part where the busbar (152) and the electrode lead (111) are connected and the battery cell (110), the part where the busbar (152) and the electrode lead (111) are connected can be separated from the space where the battery cell (110) is placed. Through this structure, it is possible to prevent the electrode lead (111) from coming into contact with an adjacent electrode lead (111) or the battery cell (110), thereby preventing a short circuit.

[0076] Meanwhile, as illustrated in FIG. 5, a battery module (100) including a busbar frame assembly (150) is provided.

[0077] The battery module (100) can be electrically connected to another battery module, BDU module, or BMS module via a busbar frame assembly (150) connected to a terminal busbar.

[0078] The battery cell (110) and battery module (100) described above are exemplary structures, and there are no special restrictions on the type or shape of the battery cell (110) and battery module (100) included in the battery pack to which the busbar frame assembly (150) according to the present embodiment is applied.

[0079] Although a pouch-type battery cell (110) has been described as an example, prismatic or cylindrical battery cells may also be applied to the battery module (100) according to the embodiment of the present invention. Additionally, although a battery module (100) in which the battery cells (110) are housed in a module frame (130) has been described as an example, a battery module (100) in the form of a CTP (cell to pack) in which multiple battery cells (110) are mounted in a battery pack without being housed in a module frame (130) may also be applied as an example of the present invention.

[0080] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0081] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0082] [Explanation of the symbol]

[0083] 100: Battery module

[0084] 110: Battery cell

[0085] 111: Electrode lead

[0086] 120: Battery cell laminate

[0087] 150: Busbar frame assembly

[0088] 151: Busbar Frame

[0089] 152: Busbar

[0090] 153: Printed circuit board

[0091] 154: Welding plate

[0092] 160: Protrusion

[0093] 161: Fastening hole

[0094] 162: Welded part

[0095] 170: Soldering section

Claims

1. A busbar connected to the electrode leads of a plurality of battery cells; and A welding plate having the above-mentioned busbar and a welded portion formed thereon; comprising The above busbar includes a plurality of protrusions, and The above welding plate includes a fastening hole into which the above protrusion is inserted. The above welded portion is a busbar frame assembly located between the plurality of protrusions.

2. In Paragraph 1, A busbar frame assembly in which the above-mentioned protrusion and the above-mentioned fastening hole are joined by soldering.

3. In Paragraph 2, A busbar frame assembly in which the above soldering joint and the above weld are formed by the same heat source.

4. In Paragraph 2, A busbar frame assembly in which the above soldering joint and the above weld are formed simultaneously.

5. In Paragraph 2, The above soldering joint is a busbar frame assembly that physically joins the above protrusion and the above fastening hole.

6. In Paragraph 1, A busbar frame assembly in which the above-mentioned protrusions include a first protrusion and a second protrusion facing each other with the above-mentioned welded portion in between.

7. In Paragraph 6, A busbar frame assembly comprising a welded portion including a first welded portion adjacent to the first protrusion and a second welded portion adjacent to the second protrusion.

8. In Paragraph 1, A busbar frame assembly in which the above-mentioned fastening hole is formed to correspond to the shape of the above-mentioned protrusion.

9. In Paragraph 1, It further includes a printed circuit board (PCB) for voltage sensing of the above battery cells, and The above printed circuit board is a busbar frame assembly connected in contact with the above welding plate.

10. In Paragraph 1, The above welding plate is a plate-shaped busbar frame assembly.

11. In Paragraph 1, A busbar frame assembly further comprising the busbar frame equipped with the above-mentioned busbar and the above-mentioned welding plate.

12. In Paragraph 11, A busbar frame assembly in which the busbar and the welding plate are mounted on the opposite side of the busbar frame facing the battery cells.

13. A battery module comprising a busbar frame assembly according to paragraph 1.

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