Busbar and battery module including same

Abstract

A busbar according to one embodiment of the present invention has a first side edge, a second side edge opposite the first side edge, and a first surface extending between the first and second side edges, and includes a first conductor layer made of a first metal, and a second conductor layer made of a second metal different from the first metal and laminated and bonded to the first surface of the first conductor layer, wherein on the first surface of the first conductor layer to which the second conductor layer is bonded, the first conductor layer has an exposed region where the first metal is exposed, and the second conductor layer extends from the first side edge of the first conductor layer toward the second side edge, leaving the exposed region of the first conductor layer.

Description

[Technical Field]

[0001] The present invention relates to a bus bar and a battery module including the same, and more particularly to a bus bar formed by joining dissimilar metals and a battery module including the same. [Background technology]

[0002] Secondary batteries are batteries that can be charged and discharged, unlike primary batteries, which cannot be charged. They are used not only in portable devices but also in electric vehicles (EVs) that are driven by electrical sources. It is applied to hybrid vehicles (HEV, Hybrid Electric Vehicle), etc.

[0003] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of such unit secondary battery cells, i.e., unit battery cells, is approximately 2.5V to 4.6V. Therefore, when a higher output voltage is required, a battery pack is constructed by connecting multiple battery cells in series. Alternatively, a battery pack may be constructed by connecting multiple battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0004] When a battery pack is constructed by connecting a number of battery cells in series / parallel, a battery module consisting of at least one battery cell, preferably a number of battery cells, is first constructed, and then at least one such battery module is used to construct the battery pack by adding other components. Here, a battery module may refer to a component in which a number of battery cells are connected in series or parallel, and a battery pack may refer to a component in which a number of battery modules are connected in series or parallel to increase capacity, output, etc.

[0005] A battery module is constructed by electrically connecting a number of cells using bus bars, and the electrode leads of the battery cells are connected to the bus bars.

[0006] However, when an electrode lead of a battery cell is connected to a bus bar, the electrode lead, which is made of a metal different from that of the bus bar, may be joined to the bus bar, which may cause corrosion and an increased crack occurrence rate at the welded surface, thereby deteriorating weldability. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a bus bar with improved weldability and a battery module including the same. [Means for solving the problem]

[0008] A busbar according to one embodiment of the present invention has a first side edge, a second side edge opposite the first side edge, and a first surface extending between the first and second side edges, and includes a first conductor layer made of a first metal, and a second conductor layer made of a second metal different from the first metal and laminated and bonded to the first surface of the first conductor layer, wherein the first conductor layer has an exposed region where the first metal is exposed on the first surface of the first conductor layer to which the second conductor layer is bonded, and the second conductor layer extends from the first side edge of the first conductor layer toward the second side edge, leaving the exposed region of the first conductor layer.

[0009] Additionally, the second conductive layer extends from the first side edge to a second side edge.

[0010] Additionally, the exposed region of the first conductive layer extends from the second side edge toward the first side edge.

[0011] The first metal or the second metal includes aluminum.

[0012] Furthermore, the first metal or the second metal includes copper.

[0013] The first conductive layer also has a through-hole.

[0014] Furthermore, the through-hole is disposed between the exposed region and the second conductive layer.

[0015] The second conductor layer also includes a first portion, a second portion extending from one end of the first portion toward a second side edge of the first conductor layer, and a third portion extending from the other end of the first portion toward the second side edge of the first conductor layer.

[0016] Additionally, the first portion of the second conductive layer is aligned with the exposed area of ​​the first conductive layer.

[0017] The first conductive layer also has a through-hole disposed between the first portion of the second conductive layer and the exposed area of ​​the first conductive layer.

[0018] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module case for accommodating the battery cell stack, and bus bars for electrically connecting the battery cells, The bus bar has a first side edge, a second side edge opposite the first side edge, and a first surface extending between the first and second side edges, and includes a first conductor layer made of a first metal, and a second conductor layer made of a second metal different from the first metal and stacked and bonded to the first surface of the first conductor layer, wherein the first conductor layer has an exposed region where the first metal is exposed on the first surface of the first conductor layer to which the second conductor layer is bonded, and the second conductor layer extends from the first side edge of the first conductor layer toward the second side edge, leaving the exposed region of the first conductor layer.

[0019] Furthermore, an electrode lead of the battery cell made of the first metal is bonded to the exposed area of ​​the first conductive layer, and an electrode lead of the battery cell made of the second metal is bonded to the second conductive layer.

[0020] Furthermore, the battery module further includes a terminal bus bar made of the first metal, and electrode leads of the battery cells made of the first metal are coupled to the terminal bus bar.

[0021] The battery module further includes a terminal bus bar made of the second metal, and electrode leads of the battery cells made of the second metal are coupled to the terminal bus bar.

[0022] The battery module further includes a bus bar frame disposed on one side of the battery cell stack, and the bus bar is disposed on the bus bar frame. [Effects of the Invention]

[0023] The bus bar and the battery module according to an embodiment of the present invention have an effect of improving weldability by homogeneously welding the electrode lead and the bus bar. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a perspective view of a battery module according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a battery module according to an embodiment of the present invention; [Figure 3] FIG. 1 is a perspective view of a battery cell according to an embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view of a terminal bus bar according to an embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of an insulating cover and an end plate according to an embodiment of the present invention. [Figure 6] FIG. 3 is a detailed view of a bus bar frame according to an embodiment of the present invention. [Figure 7] FIG. 2 is a diagram showing a bus bar to which an electrode lead is coupled in one embodiment of the present invention. [Figure 8] FIG. 2 is a diagram illustrating a bus bar according to an embodiment of the present invention. [Figure 9] FIG. 9 is an exploded perspective view of the bus bar of FIG. 8. [Figure 10] FIG. 9 is a cross-sectional view taken along the line AA in FIG. 8. [Figure 11] FIG. 9 is a rear view of the bus bar of FIG. 8. [Figure 12] 10A and 10B are diagrams illustrating bus bars according to other embodiments of the present invention. [Figure 13] 1 is a diagram illustrating a bus bar (terminal bus bar) bonding plate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The advantages and features of the present invention, as well as methods for achieving them, will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully convey the scope of the invention to those skilled in the art. The present invention is defined solely by the scope of the claims. Therefore, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid ambiguity. The same reference numerals refer to the same elements throughout the specification.

[0026] In the drawings, thicknesses of various layers and regions may be exaggerated to clearly illustrate them. Similar parts are designated by the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part between them. Conversely, when a part is described as being "directly on" another part, it means that there is no other part between them. Furthermore, when a layer, film, region, plate, or other part is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part between them. Conversely, when a part is described as being "directly under" the other part, it means that there is no other part between them.

[0027] A bus bar and a battery module 1000 according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0028] FIG. 1 is a perspective view of a battery module according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a battery module according to an embodiment of the present invention, FIG. 3 is a perspective view of a battery cell according to an embodiment of the present invention, FIG. 4 is a perspective view of a terminal bus bar according to an embodiment of the present invention, FIG. 5 is a perspective view of an insulating cover and an end plate according to an embodiment of the present invention, FIG. 6 is a detailed view of a bus bar frame according to an embodiment of the present invention, FIG. 7 is a diagram showing a bus bar to which electrode leads are coupled according to an embodiment of the present invention, FIG. 8 is a diagram illustrating a bus bar according to an embodiment of the present invention, FIG. 9 is an exploded perspective view of the bus bar of FIG. 8, FIG. 10 is a cross-sectional view taken along line AA in FIG. 8, FIG. 11 is a rear view of the bus bar of FIG. 8, FIG. 12 is a diagram illustrating a bus bar according to another embodiment of the present invention, and FIG. 13 is a diagram illustrating a bus bar (terminal bus bar) joint plate according to an embodiment of the present invention.

[0029] A battery module 1000 according to one embodiment of the present invention may include a battery cell stack 100 in which a plurality of battery cells 110 are stacked, a module case 200 that houses the battery cell stack 100, a bus bar frame 300 located on one side and / or the other side of the battery cell stack 100, an insulating cover 500 arranged on the outside of the bus bar frame 300, and an end plate 400 arranged on the outside of the insulating cover 500.

[0030] The battery cell stack 100 is formed by stacking a plurality of battery cells 110 in one direction, and the plurality of battery cells 110 may be electrically connected. The direction in which the plurality of battery cells 110 are stacked may be the X-axis direction (or the −X-axis direction) in FIG. 2 .

[0031] The direction from the front surface to the rear surface of the battery cell stack 100, or the opposite direction, is defined as the longitudinal direction of the battery cell stack 100, which may be the Y-axis direction in the drawing. Furthermore, the direction from the top surface to the bottom surface of the battery cell stack 100, or the opposite direction, is defined as the width direction of the battery cell stack 100, which may be the Z-axis direction in the drawing.

[0032] The longitudinal direction of the battery cell stack 100 may be substantially the same as the longitudinal direction of the battery cells 110. The electrode leads 111, 112 of the battery cells 110 may be located on the front and rear surfaces of the battery cell stack 100, and the bus bars 310, 320 of the battery module 1000 may be disposed near the front and rear surfaces of the battery cell stack 100 so as to easily form electrical connections with the electrode leads 111, 112.

[0033] The battery cells 110 are provided as pouch-type battery cells, which can maximize the number of battery cells that can be stacked per unit area. However, the battery cells 110 do not necessarily have to be provided in a pouch-type, and may be provided in a prismatic, cylindrical, or other various shapes.

[0034] The battery cell 110 provided in a pouch shape may include an electrode assembly and a cell case 115 that houses the electrode assembly (see FIG. 3).

[0035] The cell case 115 of the battery cell 110 is for housing the electrode assembly and may be a pouch-type cell case 115. The cell case 115 may include a lower case and an upper case covering the lower case, and the upper and lower cases may be integrated. Alternatively, as shown in Fig. 3, the connecting portion of the upper and lower cases may be folded to form a folded structure. As shown, the upper case may completely cover the lower case, and a seal portion 114 may be formed around the periphery.

[0036] The upper and lower cases may each have a laminate structure including an inner coating layer, a metal layer, and an outer coating layer. The inner coating layer is located inside the cell casing 115 relative to the metal layer and is in direct contact with the electrode assembly, so it must be insulating and electrolytic-resistant. Furthermore, the seal between the inner layers, i.e., the thermally bonded seal, must have excellent thermal adhesive strength to seal the battery from the outside. The metal layer is located between the inner and outer coating layers and serves as a barrier layer to prevent moisture and various gases from penetrating into the battery from the outside. A preferred material for the metal layer in contact with the inner coating layer is an aluminum (Al) thin film, which is lightweight yet highly formable. The outer coating layer is located outside the cell casing 115 relative to the metal layer. This outer coating layer is made of a heat-resistant polymer with excellent tensile strength, moisture barrier, and air barrier properties to protect the electrode assembly and ensure heat and chemical resistance. For example, nylon or polyethylene terephthalate may be used.

[0037] The upper and lower cases each have a receiving groove 116 in which the electrode assembly can be received.

[0038] The electrode assembly housed in the cell case 115 may be one of a group consisting of a jelly-roll type electrode assembly in which a separator is interposed between long sheet-shaped positive and negative electrodes and then wound up; a stack type electrode assembly composed of unit cells in which rectangular positive and negative electrodes are stacked with a separator interposed between them; a stack-folding type electrode assembly in which unit cells are wound up with a long separator film; and a lamination-stack type electrode assembly in which unit cells are stacked with a separator interposed between them and attached to each other.

[0039] The electrode assembly may also include two electrode tabs and two electrode leads 111, 112 connected to the electrode tabs by welds, respectively.

[0040] One of the two electrode leads 111, 112 may be a positive electrode lead connected to a positive electrode tab, and the other may be a negative electrode lead connected to a negative electrode tab. As an example, the positive electrode lead 111 may be made of aluminum (Al), and the negative electrode lead 112 may be made of copper (Cu).

[0041] A lead film 113 may be attached to each of the electrode leads 111 and 112. The lead film 113 connected to the electrode leads 111 and 112 is located between the electrode leads 111 and 112 and the cell case 115, and prevents short circuits from occurring between the electrode leads 111 and 112 and the cell case 115, and improves sealing strength to prevent electrolyte leakage.

[0042] Although the two electrode leads 111 and 112 are shown as being disposed on opposite sides of the electrode assembly, they may be disposed on only one side of the electrode assembly depending on the arrangement of the electrode tabs.

[0043] The module case 200 is intended to protect the battery cell stack 100 and the electrical components connected thereto from external physical impacts, and the module case 200 can accommodate the battery cell stack 100 and the electrical components connected thereto in the internal space of the module case 200.

[0044] The module case 200 may have a variety of structures. For example, the module case 200 may have a mono-frame structure. Here, the mono-frame may be in the form of a metal plate with an integrated top, bottom, and both side surfaces. The mono-frame may be manufactured by extrusion molding. As another example, the module case 200 may have a structure in which a U-shaped frame and an upper plate (upper surface 201) are coupled together. In the case of a structure in which a U-shaped frame and an upper plate are coupled together, the module case 200 is formed by coupling the upper plate to the top of the U-shaped frame, which is a metal plate with an integrated or coupled bottom and both side surfaces, and each frame or plate may be manufactured by press molding. Furthermore, the module case 200 may have an L-shaped frame structure in addition to the mono-frame or U-shaped frame structure, or may have various structures not described in the above examples.

[0045] The module case 200 may be provided in an open form along the longitudinal direction of the battery cell stack 100. The front and rear surfaces of the battery cell stack 100 may not be covered by the module case 200. The electrode leads 111, 112 of the battery cells 110 may not be covered by the module case 200. The front and rear surfaces of the battery cell stack 100 may be hidden by a bus bar frame 300, an end plate 400, or bus bars 310, 320, etc., which will be described later, and thereby the front and rear surfaces of the battery cell stack 100 may be protected from external physical impacts, etc.

[0046] A compression pad 150 may be positioned between the battery cell stack 100 and one of the interior surfaces of the module case 200 .

[0047] The compression pad 150 may be disposed in the battery cell stack 100 so as to face the outermost battery cell 110 of the battery cell stack 100 in the X-axis direction in the drawing.

[0048] Although not shown, a thermally conductive resin may be injected between the battery cell stack 100 and the inner surface of the module case 200, and the injected thermally conductive resin may form a thermally conductive resin layer (not shown) between the battery cell stack 100 and one of the inner surfaces of the module case 200. In this case, the thermally conductive resin layer may be located on the Z-axis of the battery cell stack 100, and the thermally conductive resin layer may be formed between the battery cell stack 100 and the bottom surface of the module case 200 located on the -Z-axis.

[0049] The bus bar frame 300 is positioned on one side of the battery cell stack 100 to cover that side and guide the connection between the battery cell stack 100 and an external device. Specifically, the bus bar frame 300 is positioned on the front or rear side of the battery cell stack 100 as shown, and may also be positioned on the top, bottom, or side. At least one of bus bars 310, 320 and a module connector may be attached to the bus bar frame 300. As shown in FIG. 2 , one side of the bus bar frame 300 may be connected to one or the other side of the battery cell stack 100, and the other side of the bus bar frame 300 may be connected to the bus bars 310, 320.

[0050] The bus bar frame 300 may be made of or include an electrically insulating material. The bus bar frame 300 may limit contact between the bus bars 310, 320 and other parts of the battery cells 110 other than the parts joined to the electrode leads 111, 112, thereby preventing electrical short circuits from occurring. The bus bar frames 300 may be located on one side and the other side of the battery cell stack 100.

[0051] 6 is a diagram illustrating a bus bar frame 300 according to one embodiment of the present invention. Bus bars 310 and 320 are attached to one side of the bus bar frame 300, and the bus bars 310 and 320 may be used to electrically connect the battery cell stack 100 or the battery cells 110 to an external device circuit. A plurality of bus bars 310 and 320 may be arranged and positioned between the battery cell stack 100 or the bus bar frame 300 and the end plate 400, thereby protecting the battery cell stack 100 or the bus bar frame 300 from external impacts and minimizing deterioration in durability due to external moisture.

[0052] The bus bars 310 and 320 may be electrically connected to the battery cell stack 100 through the electrode leads 111 and 112 of the battery cells 110 .

[0053] Specifically, the electrode leads 111 and 112 of the battery cell 110 may pass through lead slits formed in the bus bar frame 300 and then be bent to be connected to the bus bars 310 and 320 .

[0054] The bus bar 310 is used to electrically connect the battery cells. As shown in FIGS. 6 and 7, electrode leads 111 and 112 of the battery cells 110 are connected to both sides of the bus bar 310. The electrode lead 111 connected to one side of the bus bars 310 and 320 may be a positive lead, and the electrode lead 112 connected to the other side of the bus bars 310 and 320 may be a negative lead.

[0055] In this embodiment, the busbar 310 may be a clad metal busbar formed by bonding different types of metals together. As a clad metal busbar, the busbar 310 may be formed by bonding a first conductor layer 311 and a second conductor layer 315 together, and the second conductor layer 315 may be stacked on the first conductor layer 311, as shown in FIGS. 8 to 10. The busbar 310 may have through holes 312. In another embodiment, the busbar 310 may not have through holes 312. FIG. 12 illustrates a busbar 310 without through holes 312.

[0056] The first conductor layer 311 and the second conductor layer 315 may be stacked metal plates. The first conductor layer 311 may have a generally rectangular shape. The first conductor layer 311 may have a first side edge 311 a and a second side edge 311 b. The first side edge 311 a and the second side edge 311 b may be parallel and opposite each other.

[0057] The first conductive layer 311 has a first surface 311c, and a second conductive layer may be laminated on the first surface 311c. The first surface 311c may extend between the first side edge 311a and the second side edge 311b and form a plane.

[0058] The first conductor layer 311 may be made of a first metal and the second conductor layer 315 may be made of a second metal different from the first metal.

[0059] The first metal may include or be aluminum (Al), and the second metal may include or be copper (Cu).

[0060] Alternatively, the second metal may include or be aluminum (Al), and the first metal may include or be copper (Cu).

[0061] Alternatively, the first metal or the second metal may comprise an alloy of aluminum or copper with another metal.

[0062] The first conductor layer 311 has a through-hole 312 in the center as shown, and an exposed region 313 where the first metal is exposed may be formed on the first surface 311c of the first conductor layer 311 as a region where the second conductor layer 315 is not stacked. The exposed region 313 may extend from the second side edge 311b toward the first side edge 311a. The exposed region 313 does not have to extend to the first side edge 311a. The exposed region 313 may extend from the second side edge 311b to one side edge of the through-hole 312.

[0063] A positive electrode lead 111 made of a first metal (or aluminum) is joined to the exposed region 313 in the battery cell 110, and the positive electrode lead 111 can be joined to the first conductor layer 311 in the exposed region 313 by welding to be electrically connected.

[0064] The second conductor layer 315 may be laminated on the first surface 311c of the first conductor layer 311. The second conductor layer 315 may cover the entire first surface 311c of the first conductor layer 311, or may cover only a portion of the first surface 311c of the first conductor layer 311. The portion of the first surface 311c of the first conductor layer 311 that the second conductor layer 315 covers may be 50 to 80% of the first surface 311c. The exposed area 313 of the first conductor layer 311 may be 20 to 50% of the first surface 311c.

[0065] As shown in Figures 8 to 10, a second conductor layer 315 may be laminated on the first surface 311c of the first conductor layer 311 except for the exposed region 313, and an exposed region 316 may be formed on the second conductor layer 315 in the region other than the exposed region 313, the exposed region 316 being exposed to the outside.

[0066] In this embodiment, the second conductor layer 315 may be about 30 to 40%, for example, about 1 / 3, of the thickness of the first conductor layer 311. As a result, when the second metal is heavier than the first metal, for example, when the first metal includes aluminum and the second metal includes copper, the bus bar can be reduced in weight while ensuring a minimum welding strength with the electrode lead.

[0067] The second conductor layer 315 may extend from the first side edge 311 a to the second side edge 311 b of the first conductor layer 311, leaving an exposed region 313 of the first conductor layer 311. The second conductor layer 315 may extend from the first side edge 311 a to the second side edge 311 b.

[0068] The second conductor layer 315 includes a first portion 317, a second portion 318, and a third portion 319, and the first portion 317, the second portion 318, and the third portion 319 may be integral.

[0069] The first portion 317 may be disposed parallel to the exposed region 313 of the first conductor layer 311, and a through-hole 312 may be disposed between the first portion 317 and the exposed region 313. For example, the negative electrode lead 112 may be bonded to the first portion 317.

[0070] The second portion 318 may extend from one end of the first portion 317 toward the second side edge 311b. The second portion 318 may extend from one end of the first portion 317 to the second side edge 311b.

[0071] The third portion 319 may extend from the other end of the first portion 317 toward the second side edge 311b. The third portion 319 may extend from the other end of the first portion 317 to the second side edge 311b.

[0072] That is, the second portion 318 and the third portion 319 may extend in parallel from opposite ends of the first portion 317. The exposed region 313 of the first conductor layer 311 may be disposed between the second portion 318 and the third portion 319.

[0073] The first portion 317 , the second portion 318 , and the third portion 319 may form an exposed area 316 in the second conductor layer 315 .

[0074] In this embodiment, an exposed region 313 where the first conductor layer 311 is exposed and an exposed region 316 where the second conductor layer 315 is exposed are arranged together on one side of the bus bar 310, and the positive electrode lead 111 can be bonded to the exposed region 313, and the negative electrode lead 112 can be bonded to the exposed region 316.

[0075] Thus, an aluminum positive electrode lead 111 can be bonded to a first conductor layer 311 made of a first metal, which is aluminum, and a copper negative electrode lead 112 can be bonded to a second conductor layer 315 made of a second metal, which is copper.

[0076] If an electrode lead made of a metal different from that of the bus bar is joined to the bus bar, the crack occurrence rate may increase and the weldability may be reduced. In this embodiment, as described above, the positive electrode lead 111 is joined to the first conductor layer 311 made of the same metal material as the bus bar, and the negative electrode lead 112 is joined to the second conductor layer 315 made of the same metal material as the positive electrode lead 111, thereby achieving homogeneous joining, which may reduce the crack occurrence rate and improve the weldability.

[0077] The second portion 318 of the second conductor layer 315 is provided with a busbar bonding plate. 13, a busbar joint plate 310a (weld plate) may be coupled to the busbar joint plate 310a. The busbar joint plate 310a may be connected to a connector (not shown), and the connector to which the busbar joint plate 310a is connected may be connected to the connector 350 shown in FIG. 6. The connector 350 may be connected to a sensing unit (sensing plate) (not shown) and may perform functions such as voltage sensing of the battery cell 110.

[0078] That is, the sensing unit is connected to the bus bar 310 through the bus bar connecting plate 310 a coupled to the bus bar 310 , and can sense the voltage of the battery cell 110 .

[0079] In this embodiment, the bus bar bonding plate 310a may be made of a second metal (e.g., copper), and therefore may be homogeneously bonded to the second conductor layer 315 made of the second metal by welding, thereby improving weldability.

[0080] The bus bars 310, 320 can connect the battery cells 110 that make up the battery cell stack 100 in series or in parallel.

[0081] The bus bars 310, 320 may include a terminal bus bar 320 for electrically connecting one battery module 100 to another battery module 100.

[0082] At least a portion of the terminal bus bar 320 is exposed to the outside of the end plate 400 so as to be connected to another battery module 100, and the end plate 400 may be provided with a terminal opening 410 for this purpose.

[0083] One end (second portion 322 ) of terminal bus bar 320 may be exposed through opening 510 in insulating cover 500 and terminal opening 410 in end plate 400 .

[0084] 4, the terminal bus bar 320 may include a first portion 321 connected to the electrode leads 111, 112 of the battery cell 110 and a second portion 322 exposed to the outside through the terminal opening 410. The terminal bus bar 320 may further include a bending portion 323 formed between the first portion 321 and the second portion 322.

[0085] In the terminal bus bar 320, the first portion 321 is connected to the second portion 322 through the bent portion 323, and one surface of the first portion 321 and one surface of the second portion 322 may be perpendicular to each other. That is, the bent portion 323 is formed in the terminal bus bar 320, and the second portion 322 protrudes and is seated on the seat portion 530 of the insulating cover 500, so that the second portion 322 may be electrically connected to the pack bus bar (not shown). A coupling hole 322a is formed in the second portion 322 constituting one end of the terminal bus bar 320, and the second portion 322 of the terminal bus bar 320 is fixed by a fixing pin (not shown) inserted into the coupling hole 322a.

[0086] In this embodiment, two terminal bus bars 320 may be arranged on both sides of the bus bar frame 300 .

[0087] Of the two terminal bus bars 320, one terminal bus bar 320 may be a positive (+) terminal bus bar 320 and the other may be a negative (-) terminal bus bar 320.

[0088] In this embodiment, the terminal bus bar 320 on the left side in FIG. 6 is the positive (+) terminal bus bar 320 and may be made of aluminum (Al).

[0089] Positive electrode lead 111 made of the first metal is joined to left terminal bus bar 320 made of the first metal (for example, aluminum), forming a homogeneous metal joint that can improve weldability.

[0090] 4, the electrode lead 111 can be welded to the first portion 321 of the terminal bus bar 320. The terminal bus bar 320 is nickel-plated (Ni Plating and Sn plating can be done.

[0091] In addition, a terminal bus bar joint plate (terminal bus bar joint plate) is provided at the bending portion 323 of the terminal bus bar 320. A busbar weld plate) 320a can be attached (see FIG. 13).

[0092] The terminal bus bar junction plate 320a is connected to a connector (not shown) similar to the bus bar junction plate 310a, and the connector connected to the terminal bus bar junction plate 320a may be connected to the connector 350 shown in Fig. 6. The connector 350 may be connected to a sensing unit (sensing plate) (not shown) to perform functions such as voltage sensing of the battery cells 110.

[0093] That is, the sensing unit is connected to the terminal bus bar 320 through the terminal bus bar joint plate 320 a coupled to the terminal bus bar 320 to sense the voltage of the battery cell 110 .

[0094] In this embodiment, the terminal bus bar joining plate 320a may be made of a first metal (e.g., aluminum), and therefore may be homogeneously joined to the positive terminal bus bar 320 made of the first metal by welding, thereby improving weldability.

[0095] In FIG. 6, the terminal bus bar 320 on the right side is the negative (+) terminal bus bar 320 and may be made of copper (Cu).

[0096] The right terminal bus bar 320 made of a second metal (eg, copper) is joined to the negative electrode lead 112 made of a second metal, and the joining of the same metals can improve weldability.

[0097] In addition, the right terminal bus bar 320 is also provided with a terminal bus bar joint plate. A busbar weld plate) 320b can be attached.

[0098] The terminal bus bar junction plate 320b is connected to a connector (not shown) similar to the bus bar junction plate 310a, and the connector connected to the terminal bus bar junction plate 320b may be connected to the connector 350 shown in Fig. 6. The connector 350 may be connected to a sensing unit (sensing plate) (not shown) to perform functions such as voltage sensing of the battery cells 110.

[0099] In this embodiment, the terminal bus bar joining plate 320b may be made of a second metal (e.g., copper), and therefore may be homogeneously joined to the negative terminal bus bar 320 made of the second metal by welding, thereby improving weldability.

[0100] The end plates 400 may serve to protect the battery cell stack 100 and the electrical components connected thereto from external physical impacts by covering the open sides of the module case 200. To this end, the end plates 400 are made of a material having a predetermined strength, and may include, for example, a metal such as aluminum or a plastic material.

[0101] Terminal openings 410 may be formed in the end plate 400. The terminal openings 410 may be disposed on both sides of the end plate 400, and a portion of the insulating cover 500 and one end (second portion 322) of the terminal bus bar 320 may be exposed through the terminal openings 410.

[0102] A connector opening is located between the terminal openings 410 located on both sides of the end plate 400, and the module connector can be exposed to the outside through the connector opening.

[0103] The end plate 400 may be coupled to the module case 200 while covering the bus bar frame 300 or the bus bars 310, 320 located on one side of the battery cell stack 100. Each edge of the end plate 400 may be coupled to a corresponding edge of the module case 200 by welding, bolting, hook fastening, or other methods.

[0104] The end plates 400 may be positioned on one and the other sides of the module case 200 so as to cover both sides of the battery cell stack 100. In this embodiment, an example in which the end plates 400 are positioned on the front and rear sides of the module case 200 is illustrated.

[0105] The insulating cover 500 may be disposed inside the end plate 400 and outside the bus bar frame 300. Furthermore, the insulating cover 500 for electrical insulation may be located between the end plate 400 and the bus bar frame 300. That is, the bus bar frame 300, the insulating cover 500, and the end plate 400 may be sequentially located from the outside of the battery cell stack 100. As with the end plate 400, the bus bar frame 300 and the insulating cover 500 may each be configured in plurality.

[0106] The insulating cover 500 is made of or includes an electrically insulating material and can shield the bus bars 310 and 320 from contact with the end plate 400 .

[0107] The insulating cover 500 may include an opening 510 and a seat 530. The openings 510 are disposed on both sides of the upper portion of the insulating cover 500, and one end (second portion 322) of the terminal bus bar 320 may be exposed through the openings 510.

[0108] A connector opening is located between the openings 510 located on both sides of the insulating cover 500, and the module connector can be exposed to the outside through the connector opening.

[0109] The insulating cover 500 may be located on the inner surface of the end plate 400 and may be in close contact with the inner surface of the end plate 400, but is not necessarily limited to this.

[0110] As described above, one end (second portion 322) of terminal bus bar 320 is exposed through opening 510, and this exposed one end (second portion 322) of terminal bus bar 320 can be seated on seat 530. Therefore, seat 530 can be disposed adjacent to opening 510 and on the upper outer surface.

[0111] The seating portion 530 may have an upper surface on which the second portion 322 of the terminal bus bar 320 is seated, and thus the upper surface of the seating portion 530 may form a seating surface. Also, as shown in FIG. 5 , the seating portion 530 may include a fixing member 531 for fixing the terminal bus bar 320.

[0112] The fixing member 531 fixes the second portion 322 of the terminal bus bar 320 and may include a fixing hole 531a.

[0113] A fixing pin (not shown) may be inserted into the fixing hole 531 a. The fixing pin (not shown) is inserted into a coupling hole 322 a formed in the second portion 322 of the terminal bus bar 320 and coupled to and fixed in the fixing hole 531 a, thereby fixing the second portion 322 of the terminal bus bar 320 to the insulating cover 500.

[0114] Therefore, second portion 322 of terminal bus bar 320 is seated on seating portion 530 of insulating cover 500 , and second portion 322 is seated on and comes into contact with fixing member 531 arranged on seating portion 530 .

[0115] A terminal cover portion (not shown) that covers one end (second portion 322) of the exposed terminal bus bar 320 may be disposed on the insulating cover 500.

[0116] Meanwhile, electrical connections between the battery modules 1000 can be made through pack bus bars (not shown). The pack bus bars connect one battery module 1000 to another adjacent battery module 1000 or BDU (Battery Unit). The pack bus bar 320 is a member for connecting to a Disconnection Unit (DIS) and may be connected to the exposed end (second portion 322) of the terminal bus bar 320. In one example, the pack bus bar may be connected to the top of the end (second portion 322) of the terminal bus bar 320 by overlapping it.

[0117] After one end of the pack busbar is positioned overlapping the second portion 322 of the terminal busbar 320, a fixing pin is sequentially inserted into the connecting hole of the pack busbar and the connecting hole 322a of the second portion 322 of the terminal busbar 320, and the fixing pin is then fixed in the fixing groove 531a of the seat 530 to connect the pack busbar to the terminal busbar 320.

[0118] Then, the second portion 322 of the terminal bus bar 320 together with the pack bus bar can be fixed to the insulating cover 500 by a fixing pin.

[0119] As described above, one or more battery modules 1000 according to the present invention can form a battery pack. The battery pack according to the present invention can accommodate at least one battery module 1000 inside a pack case, and a BMS (Battery Management System) can be provided. This may include various control and protection systems such as the Management System, cooling system, etc.

[0120] The battery module 1000 and the battery pack according to the present invention configured as described above can be applied to various devices. Specifically, they can be applied to transportation means such as electric bicycles, electric cars, and hybrid cars, and ESS (Energy Savings System) systems. The present invention can be applied to, but is not limited to, various devices that can use secondary batteries.

[0121] As seen above, the present invention has been described with reference to preferred embodiments, but it is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the invention pertains without departing from the spirit of the present invention. [Industrial Applicability]

[0122] The present invention can provide a bus bar and a battery module in which the electrode lead and the bus bar are homogeneously welded to improve weldability.

Claims

1. A bus bar, the bus bar comprising: a first conductor layer made of a first metal, the first conductor layer having a first side edge, a second side edge opposite the first side edge, and a first surface extending between the first and second side edges; and a second conductor layer made of a second metal different from the first metal and laminated and bonded to the first surface of the first conductor layer; Including, the first conductive layer has an exposed region where the first metal is exposed on a first surface of the first conductive layer to which the second conductive layer is bonded; the second conductive layer extends from the first side edge toward the second side edge of the first conductive layer, leaving an exposed area of ​​the first conductive layer.

2. The busbar of claim 1 , wherein the second conductor layer extends from the first side edge to a second side edge.

3. The busbar of claim 1 , wherein the exposed area of ​​the first conductor layer extends from the second side edge toward the first side edge.

4. The busbar of claim 1 , wherein the first metal or the second metal comprises aluminum.

5. The busbar of claim 1 , wherein the first metal or the second metal comprises copper.

6. The busbar of claim 1 , wherein the first conductor layer has through holes.

7. The busbar of claim 6 , wherein the through-hole is disposed between the exposed region and the second conductive layer.

8. The second conductor layer comprises: A first part, a second portion extending from one end of the first portion toward a second side edge of the first conductor layer; and a third portion extending from the other end of the first portion toward a second side edge of the first conductor layer; The busbar of claim 1 , comprising:

9. The busbar of claim 8 , wherein the first portion of the second conductive layer is aligned with the exposed area of ​​the first conductive layer.

10. the first conductor layer has a through hole; The busbar of claim 8 , wherein the through hole is disposed between a first portion of the second conductive layer and an exposed area of ​​the first conductive layer.

11. A battery module, the battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a module case for accommodating the battery cell stack; and a bus bar for electrically connecting the battery cells; Including, The bus bar is a first conductor layer made of a first metal, the first conductor layer having a first side edge, a second side edge opposite the first side edge, and a first surface extending between the first and second side edges; and a second conductor layer made of a second metal different from the first metal and laminated and bonded to the first surface of the first conductor layer; Including, the first conductive layer has an exposed region where the first metal is exposed on a first surface of the first conductive layer to which the second conductive layer is bonded; the second conductive layer extends from the first side edge toward the second side edge of the first conductive layer, leaving an exposed area of ​​the first conductive layer.

12. an electrode lead of the battery cell made of the first metal is bonded to the exposed region of the first conductive layer; The battery module according to claim 11 , wherein an electrode lead of the battery cell made of the second metal is bonded to the second conductive layer.

13. 12. The battery module of claim 11, wherein the second conductor layer extends from the first side edge to the second side edge.

14. 12. The battery module according to claim 11, wherein the exposed area of ​​the first conductor layer extends from the second side edge toward the first side edge.

15. The battery module according to claim 11 , wherein the first metal or the second metal includes aluminum.

16. The battery module according to claim 11 , wherein the first metal or the second metal includes copper.

17. The battery module according to claim 11 , wherein the first conductive layer has through holes.

18. the battery module further includes a terminal bus bar made of the first metal; The battery module according to claim 11 , wherein electrode leads of the battery cells made of the first metal are coupled to the terminal bus bars.

19. the battery module further includes a terminal bus bar made of the second metal; The battery module according to claim 11 , wherein electrode leads of the battery cells made of the second metal are coupled to the terminal bus bars.

20. The battery pack further includes a bus bar frame disposed on one side of the battery cell stack, The battery module according to claim 11 , wherein the bus bars are disposed on the bus bar frame.

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