Bus bar assembly, and battery module and battery pack including same

Abstract

A bus bar assembly according to the present invention comprises a frame which covers one side or both sides of a battery cell stack and in which electrode leads of the battery cells, which constitute the battery cell stack, are stacked on one side, wherein some of the electrode leads are positive electrode leads and others are negative electrode leads.

Description

Busbar assembly, and battery module and battery pack including the same

[0001] The present invention relates to a busbar assembly and a battery module and battery pack including the same, and more specifically, to a busbar assembly with a simplified electrical connection structure between battery cells, and a battery module and battery pack including the same.

[0002] Rechargeable secondary batteries are widely used as energy sources for wireless mobile devices. In addition, secondary batteries are attracting attention as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0003] In small mobile devices, one or two or three battery cells are used per device. In contrast, in medium-to-large devices such as automobiles, due to the need for high output and large capacity, medium-to-large battery modules in which multiple battery cells are electrically connected are used, or battery packs implemented by connecting multiple battery modules are used.

[0004] In order for a medium-to-large battery module to provide the output and capacity required by a specific device or apparatus, multiple battery cells must be electrically connected in series, parallel, or a combination of series and parallel, and must be able to maintain a stable structure against external forces.

[0005] For example, as illustrated in FIG. 13, electrode leads (Al leads, Cu leads) (1000) (2000) of battery cells within a conventional battery module can be electrically connected by welding them to a plurality of interbus bars (3000) provided in the form of metal plates. In particular, the positive lead (1000) and the negative lead (2000) are each welded to both sides of the interbus bar (3000).

[0006] When electrode leads are connected by welding them to both sides of the interbusbar as in the conventional method, not only is the structure complex, but it is also difficult to reduce the weight of the battery module due to the load of the interbusbar, and there are limitations to cost reduction.

[0007] The present invention is designed to solve the problems of the prior art described above, and aims to provide a busbar assembly that can reduce weight and cost while simplifying the electrical connection structure between battery cells, as well as a battery module and a battery pack including the same.

[0008] A busbar assembly according to a preferred embodiment of the present invention for achieving the above-mentioned purpose includes a frame that covers one or both sides of a battery cell stack and on which electrode leads of battery cells constituting the battery cell stack are stacked. Some of the stacked electrode leads are positive leads and others are negative leads.

[0009] The busbar assembly according to the present invention further includes a sensing plate that is seated on a plate mounting portion of a frame, on which electrode leads of battery cells constituting a battery cell stack are stacked, and which is mutually bonded with the electrode leads.

[0010] The sensing plate senses voltage when current flows through the joined electrode leads.

[0011] The material of the sensing plate is metal.

[0012] The electrode leads stacked vertically are joined together by laser transmission welding.

[0013] The sensing plate and the electrode leads laminated on its surface are joined together by laser transmission welding.

[0014] The busbar assembly according to the present invention further includes a protective plate provided behind the sensing plate on the plate mounting portion to block the laser beam passing through the sensing plate from advancing further.

[0015] An open groove is formed in the plate seating portion, and a protective plate is inserted into the open groove.

[0016] The open groove and the protective plate have a U-shaped cross-section.

[0017] A fixing projection is formed on the plate mounting portion, and a projection insertion hole into which the fixing projection is inserted is formed on the sensing plate.

[0018] Multiple positive leads and negative leads are stacked.

[0019] Multiple lead slots are formed in the frame through which electrode leads pass.

[0020] A battery module according to a preferred embodiment of the present invention includes a battery cell stack formed by stacking a plurality of battery cells, and a busbar assembly.

[0021] According to the busbar assembly of the present invention, and the battery module and battery pack including the same, by configuring the busbar assembly in a structure in which a negative lead and an electrode lead are laminated on the surface of a sensing plate that measures voltage and then integrally bonded with the sensing plate without having an interbusbar as in the prior art, the structure of the busbar assembly can be simplified, weight can be reduced, and manufacturing costs can be lowered. This can lead to a reduction in weight and manufacturing costs of the battery module and battery pack.

[0022] In addition, when joining the electrode leads and the sensing plate integrally by laser transmission welding, using a protective plate to prevent further propagation of the laser beam can prevent damage to the equipment, including the frame of the busbar assembly, during the welding process.

[0023] FIG. 1 is a drawing showing a vehicle equipped with a battery pack according to one embodiment of the present invention.

[0024] FIG. 2 is a drawing showing a battery module according to one embodiment of the present invention embedded in a pack case.

[0025] FIG. 3 is a perspective view of a battery module according to one embodiment of the present invention.

[0026] FIG. 4 is an exploded view of a battery module according to one embodiment of the present invention.

[0027] FIG. 5 is a perspective view of a battery cell constituting a battery cell stack.

[0028] Figure 6 is a cross-sectional view showing the electrode leads of battery cells joined to a busbar assembly.

[0029] Figure 7 is an enlarged view of section A of Figure 6.

[0030] FIG. 8 is an exploded perspective view of a busbar assembly according to one embodiment of the present invention.

[0031] FIG. 9 is an enlarged front view of the plate mounting portion shown in FIG. 7 and FIG. 8.

[0032] FIG. 10 is a perspective view of a sensing plate.

[0033] FIG. 11 is a perspective view of a protective plate.

[0034] Figure 12 is a conceptual diagram showing the positive lead and the negative lead being joined to a sensing plate.

[0035] Figure 13 is a conceptual diagram showing the conventional method of joining a positive lead and a negative lead to both sides of an interbus bar.

[0036] Hereinafter, a busbar assembly according to a preferred embodiment of the present invention, and a battery module and battery pack including the same, will be described in detail with reference to the attached drawings.

[0037]

[0038] FIG. 1 is a drawing showing a vehicle equipped with a battery pack according to one embodiment of the present invention.

[0039] A vehicle (1), such as an electric vehicle or a hybrid vehicle, may be equipped with one or more battery packs (10) according to an embodiment of the present invention. The battery packs (10) can supply electrical energy required for various operations of the vehicle (1). In addition, the vehicle (1) may include various other components in addition to the battery packs (10). For example, the vehicle (1) may further include a vehicle body, a motor, an electronic control unit (ECU), and other control devices.

[0040]

[0041] FIG. 2 is a drawing showing a battery module according to one embodiment of the present invention embedded in a pack case.

[0042] A plurality of battery modules (20) according to one embodiment of the present invention may be provided and arranged in series or in parallel within a pack case (11). FIG. 2 shows an example in which battery modules (20) are arranged in two rows in parallel. As shown in FIG. 2, battery modules (20) may be arranged in the left row and the right row with the same number and spacing, respectively, and those arranged in the left row and those arranged in the right row may be arranged to face each other.

[0043]

[0044] FIG. 3 is a perspective view of a battery module according to one embodiment of the present invention, and FIG. 4 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0045] A battery module (20) according to one embodiment of the present invention may include a battery cell stack (100), a module case (200), a busbar assembly (300), an insulating cover (400), and an end plate (500).

[0046] The battery cell stack (100) includes a plurality of battery cells stacked with their wide sides facing each other and is housed in a module case (200). Each battery cell may be pouch-type.

[0047] The module case (200) is composed of a lower case (210) and an upper cover (220) and accommodates a battery cell stack (100) inside. An end plate (500) is attached to the open front and rear of the module case (200) to cover the front and rear of the module case (200).

[0048] The busbar assembly (300) is positioned on both sides of the battery cell stack (100) to cover both sides of the battery cell stack (100), electrically connect the electrode leads of the battery cells, and guide the connection between the battery cell stack (100) and an external device. Meanwhile, the busbar assembly (300) may be positioned on only one side of the battery cell stack (110) depending on the direction of the electrode leads of the battery cells constituting the battery cell stack (110).

[0049] The insulating cover (400) may include an electrical insulating material and may block the electrode leads of the battery cells, the terminal busbar, and the connector attached to the busbar assembly (300) from coming into contact with the end plate (500).

[0050] The end plate (500) can protect the battery cell stack (100) and the electrical components connected thereto from external physical impact by shielding the open side of the module case (200).

[0051]

[0052] FIG. 5 is a perspective view of a battery cell constituting a battery cell stack.

[0053] The battery cell (110) has an electrode assembly (112) housed within a pouch-shaped cell case (111), and has positive and negative electrode leads (113) (114) protruding from both sides of the cell case (111). The positive lead (113) and the negative lead (114) protrude in opposite directions. This is not limited to this, and the electrode leads (113) (114) may protrude only from one side of the cell case (111).

[0054] The electrode assembly (112) is an assembly of electrodes and a separator, and may be configured such that one or more positive plates and one or more negative plates are arranged with the separator in between. Each electrode plate of the electrode assembly may be provided with an electrode tab and connected to an electrode lead. In particular, in the case of a pouch-type secondary battery, one or more electrode tabs may be connected to an electrode lead, and the electrode lead may function as an electrode terminal by being interposed between the pouch outer material and having one end exposed to the outside. The pouch outer material may be composed of a laminate sheet having an outer insulating layer, a metal layer, and an inner adhesive layer, capable of housing the electrode assembly and electrolyte, and sealing the edges by heat-fusing.

[0055] The electrode leads (113) (114) can be made of different metal plates, with the positive lead (113) and the negative lead (114) being different. For example, the positive lead (113) can be made of an aluminum (AL) plate, and the negative lead (114) can be made of a copper (Cu) plate.

[0056]

[0057] Figure 6 is a cross-sectional view showing the electrode leads of battery cells joined to a busbar assembly.

[0058] As described above, each battery cell (110) has a positive lead (113) protruding from one side of the cell case (111) and a negative lead (114) protruding from the other side.

[0059] Battery cells (110) having such a configuration are connected to each other so that current flows. To this end, multiple battery cells (110) can be grouped together to form n battery cell bundles.

[0060] The battery cells (110) included in the same bundle have electrode leads of the same polarity placed in the same direction, and adjacent bundles may have electrode leads of different polarities placed between them.

[0061] For example, in FIG. 6, three adjacent battery cells (110) are configured as one bundle, and a total of eight bundles are configured. Based on the left side of the drawing, the positive leads of the first, third, fifth, and seventh bundles protrude forward, and the negative leads of the second, fourth, sixth, and eighth bundles adjacent to them may protrude forward.

[0062] The positive lead of the first bundle protruding forward and the negative lead of the second bundle are connected to each other, and the negative lead of the first bundle protruding backward is connected to the negative terminal busbar among the terminal busbars (320) described later.

[0063] The positive lead of the second bundle protruding backward and the negative lead of the third bundle are connected to each other, the positive lead of the third bundle protruding forward and the negative lead of the fourth bundle are connected to each other, the positive lead of the fourth bundle protruding backward and the negative lead of the fifth bundle are connected to each other, the positive lead of the fifth bundle protruding forward and the negative lead of the sixth bundle are connected to each other, the positive lead of the sixth bundle protruding backward and the negative lead of the seventh bundle are connected to each other, and the positive lead of the seventh bundle protruding forward and the negative lead of the eighth bundle are connected to each other. The positive lead of the eighth bundle protruding backward is connected to the positive terminal busbar among the terminal busbars (320) to be described later.

[0064]

[0065] FIG. 7 is an enlarged view of part A of FIG. 6, FIG. 8 is an exploded perspective view of a busbar assembly according to an embodiment of the present invention, FIG. 9 is an enlarged front view of the plate mounting portion shown in FIG. 7 and FIG. 8, FIG. 10 is a perspective view of a sensing plate, and FIG. 11 is a perspective view of a protective plate.

[0066] A busbar assembly (300) according to one embodiment of the present invention includes a frame (310), a terminal busbar (320), a connector (330), a sensing plate (340), and a protection plate (350).

[0067] The frame (310) covers both sides of the battery cell stack (100) and may be made of a material having insulating properties such as resin, and a plate mounting portion (311) is formed on the front facing the insulating cover (400) and the end plate (500) to which a sensing plate (340) and a protective plate (350) are mounted.

[0068] A plurality of plate mounting portions (311) are formed spaced apart from each other on the left and right sides, and each plate mounting portion (311) has an opening groove (312) that is open to the front. The opening groove (312) has a U-shaped cross-section. A sensing plate (340) is mounted on the front of the plate mounting portion (311) to cover the opening groove (312), and a protective plate (350) is inserted and mounted inside the opening groove (312).

[0069] In the frame (310), on the side of the plate mounting portion (311), a plurality of lead slots (313) are formed so that the electrode leads (113) (114) of the battery cells (110) constituting the battery cell stack (100) can pass through in the front and back directions.

[0070] On both the upper and lower sides of the plate mounting portion (311) in the drawing, hook-shaped fixing protrusions (314) for fixing the sensing plate (340) are formed protrudingly.

[0071] Terminal busbars (320) are mounted on each side of the frame (310) and connected to the battery cell stack (100) and external devices.

[0072] A control device capable of controlling the charging and discharging of the battery module (20), such as a BMS (Battery management system), can be connected to the connector (330).

[0073] The sensing plate (340) is made of a metal plate and is placed on the plate mounting portion (311). The sensing cells (110) can be configured in multiple bundles, and a bundle of negative leads (114) and an adjacent bundle of positive leads (113) are joined to the sensing plate (340) in a stacked state, that is, on the front surface of the sensing plate (340). In other words, multiple negative leads (114), positive leads (113), and the sensing plate (340) can be joined together and electrically connected. When current flows through the electrode leads (113) (114), the sensing plate (340) senses the voltage.

[0074] FIG. 7 shows three negative leads (114) first stacked on the front of the sensing plate (340), and three positive leads (113) stacked on top of them. As will be described later, the sensing plate (340) and the electrode leads (113) (114) stacked on its front are joined by laser transmission welding. For reference, by irradiating a laser beam toward the electrode leads (113) (114) from the front, the laser beam passes through the electrode leads (113) (114) and the sensing plate (340) and joins them as a single unit.

[0075] This sensing plate (340) includes a lead junction (341) to which electrode leads (113) (114) are joined, and a fixing part (342) extending from the upper and lower ends of the lead junction (341) and fixed to a plate mounting part (311).

[0076] The lead joint (341) is formed in a flat plate shape to cover the open groove (312) of the plate seating portion (311), and electrode leads (113) (114) are joined to the front surface thereof.

[0077] The fixed portion (342) may be composed of a flat portion extending from the lead joint portion (341) and a bent portion that is bent backward from both sides of the flat portion. A projection insertion hole (343) into which a fixing projection (314) of the plate seating portion (311) is inserted is formed in each of the bent portions. The sensing plate (340) is fixed to the plate seating portion (311) through the fixing projection (314) and the projection insertion hole (343).

[0078] The protective plate (350) is provided at the back of the sensing plate (340) in the open groove (312) of the plate mounting portion (311) to block the laser beam passing through the sensing plate (340) from advancing further, thereby protecting the battery cell (110), including the frame (310), from being affected by the laser beam. Various known materials capable of preventing the transmission of the laser beam may be used as the material for the protective plate (350). The protective plate (350) may have an open groove (351) formed that is open forward, similar to the open groove (312) of the plate mounting portion (311), so that the weight can be reduced. The cross-section of the protective plate (350) may be formed in a U-shape.

[0079]

[0080] Figure 12 is a conceptual diagram showing the positive lead and the negative lead being joined to a sensing plate.

[0081] With the protective plate (350) inserted and seated within the open groove (312) of the plate mounting portion (311), the sensing plate (340) is fixed to the front surface of the plate mounting portion (311) to cover the open groove (312). Then, negative leads (114) made of copper (Cu) plates are stacked first, followed by positive leads (113) made of aluminum (Al) plates stacked on top of them. Using a welding jig (masking jig, J), the positive leads (113) and negative leads (114) are brought into close contact with the sensing plate (340). Afterward, a laser beam (B) is irradiated from the front of the sensing plate (340) toward the sensing plate (340) using a laser irradiation device. The irradiated laser beam passes through the positive leads (113), negative leads (114), and the sensing plate (340) in sequence, welding them together as a single unit.

[0082] The laser beam loses energy as it passes through the electrode leads (113)(114) and the sensing plate (340) in sequence, and the laser beam with reduced energy is blocked from further propagation by the protective plate (350). Even if the laser beam has reduced energy, if it comes into contact with the frame (310), it can damage the frame (310). If the laser beam propagates further toward the battery cell (110) due to damage to the frame (310), it can have a negative effect on other devices besides the frame (310). The protective plate (350) can prevent such concerns in advance.

[0083]

[0084] As described above, a busbar assembly according to a preferred embodiment of the present invention, and a battery module and battery pack including the same, have been described in detail with reference to the attached drawings; however, the present invention is not limited to the above-described embodiment and can be implemented in various modified ways within the scope of the claims.

[0085] [Explanation of the symbol]

[0086] 1 : Vehicle 10 : Battery Pack

[0087] 11 : Pack case 20 : Battery module

[0088] 100 : Battery cell laminate 110 : Battery cell

[0089] 111 : Cell case 112 : Electrode assembly

[0090] 113: Positive lead 114: Negative lead

[0091] 200 : Module case 210 : Bottom case

[0092] 220 : Upper cover 300 : Busbar assembly

[0093] 310 : Frame 311 : Plate mounting part

[0094] 312 : Open groove 313 : Lead slot

[0095] 314 : Fixed projection 320 : Terminal busbar

[0096] 330 : Connector 340 : Sensing plate

[0097] 341: Lead joint 342: Fixing part

[0098] 343: Protrusion insertion hole 350: Protective plate

[0099] 351 : Open groove 400 : Insulating cover

[0100] 500 : End plate

Claims

1. A frame that covers one or both sides of a battery cell stack, wherein the electrode leads of the battery cells constituting the battery cell stack are stacked on one side; comprising, A busbar assembly in which some of the stacked electrode leads are positive leads and others are negative leads.

2. In Paragraph 1, A busbar assembly further comprising: a sensing plate that is seated on a plate mounting portion of the above frame, on which electrode leads of battery cells constituting the battery cell stack are stacked and mutually bonded with the electrode leads.

3. In Paragraph 2, The above sensing plate senses voltage when current flows through the joined electrode leads. Busbar assembly.

4. In Paragraph 3, The material of the above sensing plate is a metal material, Busbar assembly.

5. In Paragraph 3, The stacked electrode leads are joined together by laser transmission welding, Busbar assembly.

6. In Paragraph 5, The above sensing plate and the electrode leads laminated on its surface are joined together by laser transmission welding. Busbar assembly.

7. In Paragraph 6, A protective plate further comprising a plate mounted on the plate mounting portion and positioned behind the sensing plate to block a laser beam passing through the sensing plate from advancing further. Busbar assembly.

8. In Paragraph 7, An open groove is formed in the plate seating portion, and the protective plate is inserted into the open groove. Busbar assembly.

9. In Paragraph 8, The above-mentioned open groove and protective plate have a U-shaped cross-section, Busbar assembly.

10. In Paragraph 2, A fixing projection is formed on the plate mounting portion, and a projection insertion hole into which the fixing projection is inserted is formed on the sensing plate. Busbar assembly.

11. In Paragraph 1, The above positive leads and negative leads are stacked in multiple numbers. Busbar assembly.

12. In Paragraph 1, A plurality of lead slots are formed in the above frame through which the electrode leads pass. Busbar assembly.

13. A battery cell stack formed by stacking multiple battery cells; and A busbar assembly according to any one of claims 1 to 12; comprising Battery module.

14. A battery pack comprising the battery module of claim 13.

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