Battery pack and vehicle including same

Abstract

A battery pack according to the present invention comprises: multiple battery cells; a busbar assembly disposed on one side of the multiple battery cells and comprising sub-busbar units connected to the electrodes of the multiple battery cells; and a metal member supporting the multiple battery cells at the bottom of the busbar assembly. The sub-busbar units include a unidirectional connection busbar connected to the electrodes of the battery cells on one side in the width direction of the sub busbar unit. The metal member is partially connected to the unidirectional connection busbar through a predetermined current-carrying area at a predetermined position so that a current deviation does not occur in the unidirectional connection busbar.

Description

Battery pack and vehicle including same

[0001] The present invention relates to a battery pack and a vehicle including the same, and more particularly, to a battery pack capable of improving current deviation and thus extending the lifespan, and a vehicle including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0073286, filed on June 4, 2024, the entire disclosure of which is incorporated herein by reference.

[0003] Secondary batteries, which boast high electrical properties such as high energy density and easy applicability across a wide range of product categories, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical power sources. These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0004] 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 these unit secondary battery cells, i.e., unit battery cells, is approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Furthermore, depending on the charge / discharge capacity required for the battery pack, a number of battery cells are connected in parallel to form a battery pack. Therefore, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0005] Recently, medium and large battery packs applied to electric vehicles, etc. are configured to include a large number of battery cells with higher cell capacities to increase output and / or capacity, and these battery cells are electrically connected through bus bars.

[0006] For these mid- to large-sized battery packs, the safety of the busbar's electrical connection structure is relatively more critical. If large busbars are used to ensure electrical connection stability, the space occupied by these large busbars increases the overall battery pack size, hindering slimming and lowering the pack's energy density.

[0007] Therefore, in large-capacity battery packs such as mid- to large-sized battery packs, there is a need to find a way to maximize energy density while ensuring the stability of the electrical connection structure.

[0008] Furthermore, the busbars of these medium- to large-sized battery packs can carry significant currents, and current variations can be significant depending on the busbar location. Such current variations can cause current to be concentrated in specific battery cells, potentially reducing the long-term lifespan of the battery pack.

[0009] Therefore, in large-capacity battery packs such as medium- to large-sized battery packs, there is also a need to find ways to improve current deviation.

[0010] The present invention was created in consideration of the above-described problems, and its primary purpose is to provide a battery pack capable of improving current deviation and thus extending the lifespan, and an automobile including the same.

[0011] Another object of the present invention is to provide a battery pack and a vehicle including the same, which can prevent current from being concentrated on a specific battery cell.

[0012] In addition, another purpose is to provide a battery pack that is advantageous for public use and a vehicle including the same.

[0013] Another purpose is to provide a battery pack that is easy to assemble and a vehicle including the same.

[0014] In addition, another object of the present invention is to provide a battery pack and a vehicle including the same, in which a one-way connection bus bar and a metal member can be closely and firmly connected to each other.

[0015] In addition, another purpose is to provide a battery pack with improved electrical stability and rigidity and a vehicle including the same.

[0016] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0017] A battery pack according to the present invention comprises: a busbar assembly including a plurality of battery cells; a sub-busbar unit disposed on one side of the plurality of battery cells and connected to electrodes of the plurality of battery cells; and a metal member supporting the plurality of battery cells at a bottom of the busbar assembly, wherein the sub-busbar unit includes a one-way connection busbar connected to the electrodes of the battery cells at one widthwise side of the sub-busbar unit, and the metal member is partially connected to the one-way connection busbar at a predetermined position with a predetermined current-carrying area so that a current deviation does not occur in the one-way connection busbar.

[0018] The above metal member can be connected to the one-way connection bus bar so that the current-carrying area at a position relatively close to the series connection portion of the one-way connection bus bar is formed smaller than the current-carrying area at a position relatively far from the series connection portion.

[0019] The above one-way connection bus bar includes a first one-way connection bus bar connected to the negative electrode of the battery cell; and a second one-way connection bus bar connected to the positive electrode of the battery cell, and the series connection portion can be formed between the first one-way connection bus bar and the second one-way connection bus bar.

[0020] The above one-way connection bus bar includes a first one-way connection portion connected to the negative electrode of the battery cell; and a second one-way connection portion connected to the positive electrode of the battery cell and formed integrally with the first one-way connection portion, and the series connection portion can be formed at a position where the first one-way connection portion and the second one-way connection portion meet each other.

[0021] The one-way connection busbar comprises a busbar body extending in one direction; and a plurality of electrode connection portions extending from the busbar body to the electrodes of the battery cell, wherein the metal member can be connected to the one-way connection busbar by welding or conductive bonding at at least some of the connection portions among the plurality of connection portions connecting the busbar body and the electrode connection portions.

[0022] The above metal member and the one-way connection bus bar may be connected to each other at some of the plurality of connecting portions, and may not be connected to each other at some of the remaining connecting portions.

[0023] The metal member and the one-way connection bus bar are connected to each other by joining them at each of the plurality of connecting portions, and the joining areas of the metal member and the one-way connection bus bar can be formed differently at each of the plurality of connecting portions.

[0024] The one-way connection busbar comprises a busbar body extending in one direction; and a plurality of electrode connection portions extending from the busbar body to the electrode of the battery cell, wherein the metal member can be connected to the one-way connection busbar by bolting at at least some of the connection portions among the plurality of connection portions connecting the busbar body and the electrode connection portion.

[0025] The above metal member and the one-way connection bus bar may be connected to each other at some of the plurality of connecting portions, and may not be connected to each other at some of the remaining connecting portions.

[0026] The above metal member and the one-way connection bus bar are connected by bolting at each of the plurality of connecting portions, and the bolting strength can be formed differently at each of the plurality of connecting portions.

[0027] A vehicle according to the present invention comprises at least one battery pack according to the present invention.

[0028] According to the present invention, a battery pack and a vehicle including the same can be provided, which can improve the lifespan by improving current deviation through a one-way connection bus bar and a metal member.

[0029] In addition, a battery pack and a vehicle including the same can be provided that can prevent current from being concentrated on a specific battery cell by a one-way connection bus bar and a metal member.

[0030] In addition, a battery pack and a vehicle including the same that are advantageous for common use can be provided by a one-way connection bus bar.

[0031] In addition, a battery pack and a vehicle including the same that are easy to assemble can be provided by a one-way connection bus bar.

[0032] In addition, a battery pack and a vehicle including the same can be provided in which a one-way connection bus bar and a metal member can be tightly and firmly connected to each other by welding or conductive bonding.

[0033] In addition, a battery pack and a vehicle including the same can be provided in which a one-way connection bus bar and a metal member can be tightly and firmly connected to each other by bolting.

[0034] In addition, a battery pack and a vehicle including the same with improved electrical stability and rigidity can be provided by using a metal member.

[0035] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0036] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0037] FIG. 1 is a perspective view showing the overall appearance of a battery pack according to one embodiment of the present invention.

[0038] Figure 2 is a plan view showing the inside of a battery pack according to one embodiment of the present invention.

[0039] Figure 3 is a plan view showing an enlarged view of area A of Figure 2.

[0040] FIG. 4 is a perspective view showing a metal member of a battery pack according to one embodiment of the present invention.

[0041] FIG. 5 is an exploded perspective view of a busbar assembly of another battery pack according to one embodiment of the present invention.

[0042] FIG. 6 is a perspective view showing a one-way connection bus bar and a metal member connected to each other in a battery pack according to one embodiment of the present invention.

[0043] FIG. 7 is a perspective view showing a battery pack according to a modified example of one embodiment of the present invention in which a one-way connection bus bar and a metal member are connected to each other.

[0044] Figure 8 is a plan view showing an enlarged area A of Figure 2 and indicating a connection part.

[0045] FIG. 9 is an enlarged plan view of a portion of a battery pack according to another embodiment of the present invention.

[0046] FIG. 10 is an enlarged plan view of a portion of a battery pack according to a modified example of another embodiment of the present invention.

[0047] FIG. 11 is an enlarged plan view of a portion of a battery pack according to another embodiment of the present invention.

[0048] FIG. 12 is an enlarged plan view of a portion of a battery pack according to a modified example of another embodiment of the present invention.

[0049] FIG. 13 is a drawing showing a vehicle according to one embodiment of the present invention.

[0050] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0051] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and it should be understood that there may be various equivalents and modified examples that can replace them at the time of this application.

[0052]

[0053] FIG. 1 is a perspective view showing the overall appearance of a battery pack according to one embodiment of the present invention, FIG. 2 is a plan view showing the internal appearance of a battery pack according to one embodiment of the present invention, FIG. 3 is a plan view showing an enlarged view of area A of FIG. 2, and FIG. 4 is a perspective view showing a metal member of a battery pack according to one embodiment of the present invention.

[0054] Hereinafter, a battery pack (10) according to one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

[0055] A battery pack (10) according to one embodiment of the present invention may include a plurality of battery cells (100), a busbar assembly (200), and a metal member (300).

[0056] The plurality of battery cells (100) may be provided as secondary batteries, such as cylindrical secondary batteries, pouch-shaped secondary batteries, or square secondary batteries. Hereinafter, in the present embodiment, the description will be limited to the case where the plurality of battery cells (100) are provided as cylindrical secondary batteries. The plurality of battery cells (100) may be provided as a large number of battery cells (100) having a higher cell capacity to increase output and / or capacity for the configuration of a medium- to large-sized battery pack (10). The plurality of battery cells (100) may be connected in series or parallel to each other.

[0057] The busbar assembly (200) can be connected to a plurality of battery cells (100). The busbar assembly (200) can be arranged on one side of the plurality of battery cells (100). Specifically, the busbar assembly (200) can be arranged on the upper side (+Z direction side) of the plurality of battery cells (100) and connected to the plurality of battery cells (100) in one direction.

[0058] The busbar assembly (200) may include a sub-busbar unit (210) connected to electrodes (110, 120) of a plurality of battery cells (100). The sub-busbar unit (210) may be connected in series and parallel to the electrodes (110, 120) of the plurality of battery cells (100). As the sub-busbar unit (210) is connected to the electrodes (110, 120) of the plurality of battery cells (100), the busbar assembly (200) may be electrically connected to the plurality of battery cells (100).

[0059] The sub-busbar unit (210) may include a one-way connection busbar (220). The one-way connection busbar (220) may be connected to an electrode (110, 120) of a battery cell (100) at one widthwise side (+Y direction side or -Y direction side) of the sub-busbar unit (210). The one-way connection busbar (220) may be connected to the electrodes (110, 120) of a plurality of battery cells (100).

[0060] Figures 1 and 2 schematically illustrate the flow of current (C) formed by a plurality of battery cells (100). Here, the current (C) can be understood as the charging current of the battery pack (10).

[0061] A metal member (300) can support a plurality of battery cells (100). The metal member (300) can be disposed at the bottom of the busbar assembly (200). For example, the metal member (300) can be disposed at the lower side (-Z direction side) of the busbar assembly (200). The metal member (300) can be connected to a one-way connection busbar (220). The metal member (300) can be electrically connected to the one-way connection busbar (220). For example, the upper surface (310) of the metal member (300) can be connected to the one-way connection busbar (220). The metal member (300) can increase the cross-sectional area of ​​the one-way connection busbar (220), thereby improving the electrical stability of the one-way connection busbar (220).

[0062] The metal member (300) may be partially connected to the one-way connection bus bar (220) at a predetermined position. Specifically, when viewed from a predetermined direction, the metal member (300) and the one-way connection bus bar (220) may overlap each other, and the metal member (300) and the one-way connection bus bar (220) may be partially connected to each other at a predetermined position within the overlapping area, but not in the entire overlapping area. For example, as illustrated in FIG. 3, when viewed from the top and bottom (Z-axis direction), the metal member (300) and the one-way connection bus bar (220) may overlap each other, and may be partially connected to each other only at some positions within the overlapping area. In addition, the predetermined position may be at least one of a plurality of positions that are closest to each battery cell (100) in the area where the upper surface (310) of the metal member (300) and the one-way connection bus bar (220) overlap.

[0063] The metal member (300) can be partially connected to the one-way connection bus bar (220) at the predetermined position with a predetermined current-carrying area. Here, the current-carrying area can be understood as the cross-sectional area of ​​the portion where the metal member (300) and the one-way connection bus bar (220) are mutually current-carrying, i.e., electrically connected.

[0064] The electrical resistance between the metal member (300) and the one-way connection bus bar (220) may be inversely proportional to the current-carrying area. Therefore, if the current-carrying area of ​​the one-way connection bus bar (220) is changed depending on the position, the electrical resistance value between the metal member (300) and the one-way connection bus bar (220) may be formed differently depending on the position.

[0065] The metal member (300) may be partially connected to the one-way connection bus bar (220) so that current deviation does not occur in the one-way connection bus bar (220). For example, in the one-way connection bus bar (220), the electric resistance value may be formed to be high in a portion where relatively high current may flow, and the electric resistance value may be formed to be low in a portion where relatively low current may flow, so that current deviation does not occur in the entire one-way connection bus bar (220). The metal member (300) may be connected to the one-way connection bus bar (220).

[0066] In the case of a conventional battery pack (10), currents of different magnitudes may be formed at different locations in the one-way connection bus bar (220) connected to the electrodes (110, 120) of a plurality of battery cells (100). As a result, in the conventional battery pack (10), there was a problem that the current could be concentrated on a specific battery cell (100), and the lifespan of the battery pack (10) could be reduced. However, the metal member (300) of the battery pack (10) according to the present invention can prevent current deviation from occurring in the one-way connection bus bar (220), effectively preventing the current from being concentrated on a specific battery cell (100), and the lifespan of the battery pack (10) can be significantly improved.

[0067]

[0068] The metal member (300) can be connected to the one-way connection bus bar (220) with a different current-carrying area depending on the distance from the series connection portion (SP) of the one-way connection bus bar (220). Specifically, the current-carrying area between the metal member (300) and the one-way connection bus bar (220) at a position relatively close to the series connection portion (SP) can be formed to be smaller than the current-carrying area between the metal member (300) and the one-way connection bus bar (220) at a position relatively far from the series connection portion (SP).

[0069] The series connection portion (SP) of the one-way connection bus bar (220) will be described in detail. Positive electrodes of a plurality of battery cells (100) may be connected to one side of the one-way connection bus bar (220), and negative electrodes of other plurality of battery cells (100) may be connected to the other side of the one-way connection bus bar (220). At this time, the one side of the one-way connection bus bar (220) and the other side of the one-way connection bus bar (220) may be electrically connected to each other in series, and it may be understood that the portion electrically connected in series in this way is the series connection portion (SP). The series connection portion (SP) is an electrically connected portion, and does not necessarily need to be physically present on the one-way connection bus bar (220).

[0070] Meanwhile, in a one-way connection bus bar (220), the closer it is to the series connection part (SP), the higher the possibility that a relatively high current will flow.

[0071] When the metal member (300) and the one-way connection bus bar (220) are connected as described above, the electrical resistance between the metal member (300) and the one-way connection bus bar (220) may be formed to be relatively large the closer it is to the series connection portion (SP). Conversely, the electrical resistance between the metal member (300) and the one-way connection bus bar (220) may be formed to be relatively small the farther it is from the series connection portion (SP). As a result, the electrical resistance may be formed to be relatively large in a portion where a relatively high current may flow, so that the occurrence of current deviation depending on the position of the one-way connection bus bar (220) can be more effectively prevented.

[0072]

[0073] FIG. 5 is an exploded perspective view of a busbar assembly of a battery pack according to one embodiment of the present invention, and FIG. 6 is a perspective view showing a one-way connection busbar and a metal member connected to each other in a battery pack according to one embodiment of the present invention.

[0074] Hereinafter, with reference to FIGS. 3 to 6, a one-way connection bus bar (220) of a battery pack (10) according to one embodiment of the present invention will be described in more detail.

[0075] The one-way connection bus bar (220) may include a first one-way connection bus bar (220-1) and a second one-way connection bus bar (220-2). The first one-way connection bus bar (220-1) may be connected to a negative electrode of a battery cell (100). The first one-way connection bus bar (220-1) may include a first bus bar body (221-1) having a predetermined length. The first bus bar body (221-1) may be extended in the X direction. The first one-way connection bus bar (220-1) may include at least one negative electrode connection portion (222) connected to the first bus bar body (221-1) and the negative electrode of the battery cell (100).

[0076] The second one-way connecting bus bar (220-2) may be connected to the positive electrode of the battery cell (100). The second one-way connecting bus bar (220-2) may include a second bus bar body (221-2) having a predetermined length. The second bus bar body (221-2) may be extended in the X direction. The second one-way connecting bus bar (220-2) may include at least one positive electrode connecting portion (223) connected to the second bus bar body (221-2) and the positive electrode of the battery cell (100).

[0077] A one-way connection busbar (220) may include a busbar body (221). The busbar body (221) may be understood as a collective term for the first busbar body (221-1) and the second busbar body (221-2) described above.

[0078] The serial connection portion (SP) may be formed between the first unidirectional connection bus bar (220-1) and the second unidirectional connection bus bar (220-2). When the first unidirectional connection bus bar (220-1) and the second unidirectional connection bus bar (220-2) are spaced apart from each other, the serial connection portion (SP) may be formed between the first unidirectional connection bus bar (220-1) and the second unidirectional connection bus bar (220-2) in the metal member (300).

[0079] In this way, when the one-way connection bus bar (220) includes a first one-way connection bus bar (220-1) and a second one-way connection bus bar (220-2), there is an advantage in that it is advantageous for common use of the one-way connection bus bar (220) in the battery pack (10).

[0080]

[0081] FIG. 7 is a perspective view showing a battery pack according to a modified example of one embodiment of the present invention in which a one-way connection bus bar and a metal member are connected to each other.

[0082] Hereinafter, with reference to FIG. 7, a one-way connection bus bar (220) of a battery pack (10) according to a modified example of an embodiment of the present invention will be described in detail. Unlike the one embodiment of the present invention, the one-way connection bus bar (220) of the battery pack (10) according to a modified example of an embodiment of the present invention may include a first one-way connection portion (220-3) and a second one-way connection portion (220-4).

[0083] The first unidirectional connection (220-3) may be connected to the negative electrode of the battery cell (100). The first unidirectional connection (220-3) may include at least one negative electrode connection (222) connected to the negative electrode of the battery cell (100).

[0084] The second one-way connection (220-4) may be connected to the positive electrode of the battery cell (100). The second one-way connection (220-4) may include at least one positive connection (223) connected to the positive electrode of the battery cell (100).

[0085] The second one-way connection portion (220-4) may be formed integrally with the first one-way connection portion (220-3). The one-way connection bus bar (220) may include a bus bar body (221). In the bus bar body (221), the portion where the negative connection portion (222) is arranged may be the first one-way connection portion (220-3), and the portion where the positive connection portion (223) is arranged may be the second one-way connection portion (220-4).

[0086] The serial connection portion (SP) can be formed at a location where the first unidirectional connection portion (220-3) and the second unidirectional connection portion (220-4) meet.

[0087] In this way, when the one-way connection bus bar (220) includes a first one-way connection portion (220-3) and a second one-way connection portion (220-4), assembly of the one-way connection bus bar (220) can be facilitated when assembling the battery pack (10).

[0088]

[0089] Figure 8 is a plan view showing an enlarged area A of Figure 2 and indicating a connection part.

[0090] Hereinafter, with reference to FIGS. 6 and 8, a battery pack (10) according to one embodiment of the present invention will be described in more detail.

[0091] As described above, the one-way connection bus bar (220) may include a bus bar body (221) and electrode connection portions (222, 223). At this time, a portion where the bus bar body (221) and the electrode connection portions (222, 223) are connected to each other may be defined as a connection portion (CN). A plurality of connection portions (CN) may be formed in the bus bar body (221). The metal member (300) may be connected to the one-way connection bus bar (220) in at least some of the connection portions (CN) among the plurality of connection portions (CN).

[0092]

[0093] FIG. 9 is a plan view showing an enlarged portion of a battery pack (10) according to another embodiment of the present invention, and FIG. 10 is a plan view showing an enlarged portion of a battery pack (10) according to a modified example of another embodiment of the present invention.

[0094] Hereinafter, with reference to FIGS. 8 to 10, a battery pack (10) according to another embodiment of the present invention will be described in detail.

[0095] According to another embodiment of the present invention, a metal member (300) of a battery pack (10) may be connected to a one-way connection bus bar (220) by welding or conductive bonding at at least some of the plurality of connecting portions (CN). Here, the connecting portion (CN) where welding or conductive bonding is performed may be defined as a joint portion (A).

[0096] The above welding may be performed using laser welding. Conductive bonding may be understood as bonding the metal member (300) and the one-way connection bus bar (220) to each other using a conductive adhesive. The conductive adhesive may be, for example, an electrically conductive epoxy adhesive. In this way, when the metal member (300) and the one-way connection bus bar (220) are connected to each other by welding or conductive bonding, they can be tightly and firmly connected to each other.

[0097] The metal member (300) and the one-way connection bus bar (220) may be connected to each other in some of the plurality of connection portions (CN), and may not be connected to each other in some of the remaining connection portions (CN) among the plurality of connection portions (CN).

[0098] For example, in a connection (CN) located relatively far from a serial connection portion (SP) among a plurality of connection portions (CN), a metal member (300) and a one-way connection bus bar (220) may be connected to each other, and in a connection (CN) located relatively close to a serial connection portion (SP) among a plurality of connection portions (CN), a metal member (300) and a one-way connection bus bar (220) may not be connected to each other.

[0099] For example, as illustrated in FIG. 9, when four connection parts (CN) are formed on the +X-direction side and the -X-direction side respectively based on the series connection part (SP), the metal member (300) and the one-way connection bus bar (220) may not be connected to each other at the two connection parts (CN) on the +X-direction side and the two connection parts (CN) on the -X-direction side adjacent to the series connection part (SP). In addition, a joint part (A) may be formed at the two connection parts (CN) on the +X-direction side and the two connection parts (CN) on the -X-direction side far from the series connection part (SP), so that the metal member (300) and the one-way connection bus bar (220) may be connected to each other. However, FIG. 9 is merely an example, and the connection structure of the metal member (300) and the one-way connection bus bar (220) is not limited thereto.

[0100] In this way, when the metal member (300) and the one-way connection bus bar (220) are connected to each other at some of the connection portions (CN) among the plurality of connection portions (CN) and are not connected to each other at the remaining connection portions (CN) among the plurality of connection portions (CN), there is an advantage in that the current deviation of the one-way connection bus bar (220) can be improved in a simple manner.

[0101] The metal member (300) and the one-way connection bus bar (220) can be connected to each other by being joined to each other at each of a plurality of connection portions (CN). In addition, the joint areas of the metal member (300) and the one-way connection bus bar (220) can be formed differently at each of the plurality of connection portions (CN). That is, a joint portion (A) is formed at each of the plurality of connection portions (CN), but the joint area of ​​the joint portion (A) can be formed differently at each of the connection portions (A).

[0102] For example, in a connection (CN) located relatively far from a serial connection portion (SP) among a plurality of connection portions (CN), a joint area between a metal member (300) and a one-way connection bus bar (220) may be formed relatively large, and in a connection (CN) located relatively close to a serial connection portion (SP) among a plurality of connection portions (CN), a joint area between a metal member (300) and a one-way connection bus bar (220) may be formed relatively small.

[0103] For example, as illustrated in FIG. 10, when four connection parts (CN) are formed on the +X direction side and the -X direction side respectively with respect to the series connection part (SP), the bonding area of ​​the metal member (300) and the one-way connection bus bar (220) can be formed to be larger as it gets farther away from the series connection part (SP). In this case, the electrical resistance of the one-way connection bus bar (220) can decrease as it gets farther away from the series connection part (SP).

[0104] In this way, when the metal member (300) and the one-way connection bus bar (220) are connected by being joined to each other at each of the multiple connection portions (CN) and the joining area is formed differently at each of the multiple connection portions (CN), the current-carrying area for each position of the one-way connection bus bar (220) can be more precisely controlled, so there is an advantage in that the current deviation of the one-way connection bus bar (220) can be more effectively improved.

[0105]

[0106] FIG. 11 is an enlarged plan view of a portion of a battery pack according to another embodiment of the present invention, and FIG. 12 is an enlarged plan view of a portion of a battery pack according to a modified example of another embodiment of the present invention.

[0107] Hereinafter, with reference to FIGS. 8, 11 and 12, a battery pack (10) according to another embodiment of the present invention will be described in detail.

[0108] According to another embodiment of the present invention, a metal member (300) of a battery pack (10) can be connected to a one-way connection bus bar (220) by bolting at at least some of the connecting portions (CN) among a plurality of connecting portions (CN).

[0109] The above bolting fastening can be achieved by fastening a bolt member (B). The bolt member (B) can be fastened to a metal member (300) by penetrating a one-way connection bus bar (220). The bolt member (B) can be fastened with a predetermined bolting strength. The metal member (300) and the one-way connection bus bar (220) can be brought into contact with each other by the bolt member (B). The contact area between the metal member (300) and the one-way connection bus bar (220) can be proportional to the bolting strength of the bolt member (B). In this way, when the metal member (300) and the one-way connection bus bar (220) are connected by bolting fastening, they can be tightly and firmly connected to each other.

[0110] The metal member (300) and the one-way connection bus bar (220) may be connected to each other in some of the plurality of connection portions (CN), and may not be connected to each other in some of the remaining connection portions (CN) among the plurality of connection portions (CN).

[0111] For example, in a connection (CN) located relatively far from a serial connection portion (SP) among a plurality of connection portions (CN), a metal member (300) and a one-way connection bus bar (220) may be connected to each other, and in a connection (CN) located relatively close to a serial connection portion (SP) among a plurality of connection portions (CN), a metal member (300) and a one-way connection bus bar (220) may not be connected to each other.

[0112] For example, as illustrated in FIG. 11, when four connection parts (CN) are formed on the +X-direction side and the -X-direction side respectively based on the series connection part (SP), the metal member (300) and the one-way connection bus bar (220) may not be connected to each other at the two connection parts (CN) on the +X-direction side and the two connection parts (CN) on the -X-direction side adjacent to the series connection part (SP). In addition, the metal member (300) and the one-way connection bus bar (220) may be connected to each other at the two connection parts (CN) on the +X-direction side and the two connection parts (CN) on the -X-direction side far from the series connection part (SP). However, FIG. 11 is merely an example, and the connection structure of the metal member (300) and the one-way connection bus bar (220) is not limited thereto.

[0113] In this way, when the metal member (300) and the one-way connection bus bar (220) are connected to each other at some of the connection portions (CN) among the plurality of connection portions (CN) and are not connected to each other at the remaining connection portions (CN) among the plurality of connection portions (CN), there is an advantage in that the current deviation of the one-way connection bus bar (220) can be improved in a simple manner.

[0114] The metal member (300) and the one-way connection bus bar (220) can be connected by bolting at each of a plurality of connection portions (CN). In addition, the bolting strength of the bolt member (B) that bolts the metal member (300) and the one-way connection bus bar (220) can be formed differently at each of the plurality of connection portions (CN).

[0115] For example, in a connection (CN) located relatively far from a serial connection portion (SP) among a plurality of connection portions (CN), the bolting fastening strength may be formed relatively strong, so that a contact area between a metal member (300) and a one-way connection bus bar (220) may be formed relatively large. In addition, in a connection (CN) located relatively close to a serial connection portion (SP) among a plurality of connection portions (CN), the bolting fastening strength may be formed relatively weak, so that a contact area between a metal member (300) and a one-way connection bus bar (220) may be formed relatively small.

[0116] For example, as illustrated in Fig. 12, when four connection parts (CN) are formed on the +X direction side and the -X direction side based on the series connection part (SP), all connection parts (CN) are bolted, but the bolting strength can be formed to be stronger the farther away from the series connection part (SP). In this case, the electrical resistance of the one-way connection bus bar (220) can decrease the farther away from the series connection part (SP).

[0117] In this way, when the metal member (300) and the one-way connection bus bar (220) are connected by bolting to each other at each of the multiple connection portions (CN) and the bolting strength is formed differently at each of the multiple connection portions (CN), the current-carrying area for each position of the one-way connection bus bar (220) can be adjusted more precisely and simply, so there is an advantage in that the current deviation of the one-way connection bus bar (220) can be improved more effectively.

[0118]

[0119] Hereinafter, with reference again to FIGS. 3 and 4, the one-way connection bus bar (220), metal member (300), and side frame of the battery pack (10) according to the present invention will be described in more detail.

[0120] The one-way connection bus bar (220) may be formed to be elongated so that at least a portion thereof has a predetermined length. The metal member (300) may be formed to be elongated so that it has a predetermined length in the longitudinal direction of the one-way connection bus bar (220). The one-way connection bus bar (220) and the metal member (300) may overlap each other in at least a portion of the longitudinal direction. The one-way connection bus bar (220) and the metal member (300) may be electrically and physically connected to each other so that they have a predetermined current-carrying area at a predetermined position among the overlapping areas. For example, as illustrated in FIG. 3, the one-way connection bus bar (220) and the metal member (300) may each be elongated in the X direction. When viewed from the top-down direction (Z-axis direction), the one-way connection bus bar (220) and the metal member (300) can overlap each other at least in some areas, and the one-way connection bus bar (220) and the metal member (300) can be connected to each other to have a predetermined current-carrying area at a specific position in the X-direction of the area where they overlap each other.

[0121] The metal member (300) may include an upper surface (310) and an insertion portion (320). The upper surface (310) may face the sub-busbar unit (210) so as to overlap with the sub-busbar unit (210) at least in a portion thereof. The upper surface (310) may face the bottom of the sub-busbar unit (210). A concave portion (311) and a convex portion (312) may be formed on the upper surface (310). A battery cell (100) may be accommodated in the concave portion (311). The convex portion (312) may be formed between the concave portions (311). The convex portion (312) may be positioned between the battery cells (100). The insertion portion (320) may be inserted into and fixed to a side frame described below. The upper surface (310) may have a predetermined length and width. For example, the upper surface (310) may be elongated in the X-axis direction and have a width in the Y-axis direction. The insertion portion (320) may have a predetermined length and width. For example, the insertion portion (320) may be elongated in the X-axis direction and have a width in the Z-axis direction. The cross-section of the upper surface (310) and the cross-section of the insertion portion (320) may be formed perpendicular to each other.

[0122] A battery pack (10) according to the present invention may include side frames (410, 420). The side frames (410, 420) may support a plurality of battery cells (100) at the bottom (-Z-axis direction) of the busbar assembly (200). The side frames (410, 420) may support other components constituting the busbar assembly (200) and the battery pack (10) in addition to the plurality of battery cells (100).

[0123] The side frame (410, 420) may include a side wall (410) and a side structure (420). The side walls (410) may be provided as a pair on the outermost sides of the side frames (410, 420). The side walls (410) may accommodate and support a plurality of battery cells (100) in at least one row. The side walls (410) may have a predetermined length. For example, the side walls (410) may extend in the X direction.

[0124] The side structure (420) can support a plurality of battery cells (100). At least one side structure (420) can be provided on the inner side of a pair of side walls (410). The side structure (420) can accommodate and support a plurality of battery cells (100) in two rows. The side structure (420) can have a predetermined length. For example, the side structure (420) can be extended in the X direction.

[0125] The metal member (300) can be placed on the side wall (410). The metal member (300) can be inserted into the side wall (410) and fixedly placed. Specifically, the insertion portion (320) of the metal member (300) can be inserted into the side wall (410) in the Z direction and fixedly placed. As the metal member (300) is placed on the side wall (410), the rigidity of the side wall (410) can be reinforced.

[0126]

[0127] Hereinafter, with reference to FIGS. 3 to 5 again, the busbar assembly (200) of the battery pack (10) according to the present invention will be described in more detail.

[0128] According to one embodiment of the present invention, a busbar assembly (200) may include a sub-busbar unit (210) that includes a bidirectional connection busbar (230). The bidirectional connection busbar (230) may be connected to electrodes (110, 120) of a battery cell (100) on both sides (+Y direction side and -Y direction side) in the width direction of the sub-busbar unit (210). The unidirectional connection busbar (220) may be arranged on each of the outermost sides (-Y direction side and +Y direction side) of the sub-busbar unit (210), and the bidirectional connection busbar (230) may be arranged between the unidirectional connection busbars (220).

[0129] The busbar assembly (200) may include a busbar cover (240, 250). The busbar cover (240, 250) may be provided to cover the upper side (+Z direction side) of a plurality of battery cells (100). The busbar cover (240, 250) may be provided with an insulating material.

[0130] The busbar covers (240, 250) may be provided to be mutually coupled with each other with the sub-busbar unit (210) therebetween. Specifically, the busbar covers (240, 250) may include a first busbar cover (240) and a second busbar cover (250). Guide openings (241, 251) may be formed in the busbar covers (240, 250). Electrodes of the battery cell (100) may be exposed through the guide openings (241, 251). The guide openings (241, 251) may include a first guide opening (241) formed in the first busbar cover (240) and a second guide opening (252) formed in the second busbar cover (250).

[0131]

[0132] Hereinafter, referring again to FIG. 1, a pack case (500) of a battery pack (10) according to the present invention will be described in detail. The battery pack (10) according to the present invention may include a pack case (500). The pack case (500) may accommodate a plurality of battery cells (100). The pack case (500) may include a side wall portion, a bottom plate, and a pack lid, etc.

[0133]

[0134] Meanwhile, the battery pack (10) according to the present invention may further include various devices for controlling charging and discharging of battery cells (100), such as a BMS (Battery Management System), a current sensor, a fuse, etc., although not shown.

[0135]

[0136] FIG. 13 is a drawing showing a vehicle according to one embodiment of the present invention.

[0137] Hereinafter, referring to FIG. 13, the battery pack (10) according to the present invention can be applied to a vehicle (V) such as an electric vehicle or a hybrid vehicle. That is, the vehicle (V) according to the present invention can include the battery pack (10) according to the present invention. The battery pack (10) can be installed in a body frame or a trunk space under a vehicle seat. In addition to the battery pack (10), the vehicle (V) according to an embodiment of the present invention can further include various other components included in the vehicle. For example, the vehicle (V) according to an embodiment of the present invention can further include a body, a motor, a control device such as an ECU (electronic control unit), etc., in addition to the battery pack (10) according to an embodiment of the present invention.

[0138] In addition, it goes without saying that the battery pack (10) according to one embodiment of the present invention may be installed in other devices, apparatuses, and facilities, such as energy storage systems that use secondary batteries, in addition to automobiles (V).

[0139]

[0140] In this specification, terms indicating directions such as up, down, left, right, front, and back are used, but these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the location of the target object or the location of the observer.

[0141] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below.

[0142] [Explanation of symbols]

[0143] 10: Battery pack

[0144] 100: Battery Cell

[0145] 110: Anode

[0146] 120: Cathode

[0147] 200: Busbar assembly

[0148] 210: Sub busbar unit

[0149] 220: One-way connection busbar

[0150] 221: Busbar body

[0151] 221-1: First busbar body

[0152] 221-2: Second busbar body

[0153] 222: Negative connection

[0154] 223: Positive connection

[0155] 220-1: 1st direction connection bus bar

[0156] 220-2: Second-direction connection bus bar

[0157] 220-3: First-way connection

[0158] 220-4: Second one-way connection

[0159] 230: Two-way connection busbar

[0160] 240: 1st busbar cover

[0161] 241: First guide opening

[0162] 250: Second busbar cover

[0163] 251: Second guide opening

[0164] 300: Metal parts

[0165] 310: Top surface

[0166] 311: Concave

[0167] 312: Convex part

[0168] 320: Insertion part

[0169] 410: Side wall

[0170] 420: Side Structure

[0171] 500: Pack Case

[0172] C: Current

[0173] SP: Serial connection part

[0174] CN: Connection

[0175] A: Joint

[0176] B: Bolt member

[0177] V: Car

Claims

1. Multiple battery cells; A busbar assembly including a sub-busbar unit disposed on one side of the plurality of battery cells and connected to electrodes of the plurality of battery cells; and A metal member supporting the plurality of battery cells at the bottom of the busbar assembly is included, The above sub-busbar unit is, A one-way connection bus bar connected to the electrodes of the battery cells on one side of the width direction of the above sub-bus bar unit is included, The above metal member, A battery pack characterized in that it is partially connected to the one-way connection bus bar at a predetermined location with a predetermined current-carrying area so that current deviation does not occur in the one-way connection bus bar.

2. In paragraph 1, The above metal member, A battery pack characterized in that it is connected to the one-way connection bus bar so that the current carrying area at a position relatively close to the series connection portion of the one-way connection bus bar is formed smaller than the current carrying area at a position relatively far from the series connection portion.

3. In paragraph 2, The above one-way connection busbar is, A first unidirectional connection bus bar connected to the negative electrode of the above battery cell; and Includes a second unidirectional connection bus bar connected to the positive electrode of the above battery cell, The above serial connection part is, A battery pack characterized in that it is formed between the first one-way connection bus bar and the second one-way connection bus bar.

4. In paragraph 2, The above one-way connection busbar is, A first unidirectional connection connected to the negative electrode of the battery cell; and It includes a second unidirectional connection portion connected to the positive electrode of the battery cell and formed integrally with the first unidirectional connection portion, The above serial connection part is, A battery pack characterized in that the first unidirectional connection portion and the second unidirectional connection portion are formed at a position where they meet each other.

5. In paragraph 1, The above one-way connection busbar is, A busbar body extended in one direction; and comprising a plurality of electrode connections extending from the busbar body to the electrodes of the battery cell; The above metal member, A battery pack characterized in that at least some of the connecting portions among the plurality of connecting portions connecting the busbar body and the electrode connecting portion are connected to the one-way connecting busbar by welding or conductive bonding.

6. In paragraph 5, The above metal member and the one-way connection bus bar, Some of the above multiple connecting portions are connected to each other, A battery pack characterized in that some of the remaining connections among the above plurality of connections are not connected to each other.

7. In paragraph 5, The above metal member and the one-way connection bus bar, The above multiple connecting portions are connected to each other by joining, The joint area of ​​the above metal member and the one-way connection bus bar is A battery pack characterized in that the plurality of connecting portions are formed differently from each other.

8. In paragraph 1, The above one-way connection busbar is, A busbar body extended in one direction; and comprising a plurality of electrode connections extending from the busbar body to the electrodes of the battery cell; The above metal member, A battery pack characterized in that at least some of the plurality of connecting portions connecting the busbar body and the electrode connecting portion are connected to the one-way connecting busbar by bolting.

9. In paragraph 8, The above metal member and the one-way connection bus bar, Some of the above multiple connecting portions are connected to each other, A battery pack characterized in that some of the remaining connections among the above plurality of connections are not connected to each other.

10. In paragraph 8, The above metal member and the one-way connection bus bar, Each of the above multiple connecting parts is connected by bolting, A battery pack characterized in that the bolting fastening strength is formed differently in the plurality of connecting portions.

11. A vehicle characterized by including at least one battery pack according to any one of claims 1 to 10.

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