Power storage device

Abstract

This power storage device includes: a plurality of power storage modules that include a plurality of power storage cells arranged along a first direction and that are arranged along a second direction intersecting the first direction; a positive electrode bus bar that is connected to positive electrodes of the plurality of power storage modules and that is led out to one side of the plurality of power storage modules along the first direction; a negative electrode bus bar that is connected to negative electrodes of the plurality of power storage modules and that is led out to the one side of the plurality of power storage modules; and an electric device that is electrically connected to both the positive electrode bus bar and the negative electrode bus bar and that is disposed on the one side of the plurality of power storage modules.

Description

Power storage device

[0001] The technology of the present disclosure relates to a power storage device.

[0002] Japanese Unexamined Patent Application Publication No. 2023-046719 describes a structure in which a battery pack including a housing case, a busbar and a battery stack accommodated inside the housing case is mounted on a vehicle.

[0003] For a power storage device for driving a vehicle, particularly a battery electric vehicle (BEV) or a hybrid electric vehicle (HEV), the battery capacity greatly affects the driving performance of the vehicle including the cruising range. From this point of view, it is required to realize a power storage device with a large battery capacity in a space-saving manner that has little impact on vehicle size and cabin space.

[0004] In view of the above-mentioned problems, the present disclosure provides a power storage device that can achieve a desired battery capacity in a space-saving manner.

[0005] The power storage device according to a first aspect includes a plurality of power storage cells arranged along a first direction, and includes: a plurality of power storage modules arranged along a second direction intersecting the first direction; a positive electrode busbar connected to positive electrodes of the plurality of power storage modules and led out to one side of the plurality of power storage modules along the first direction; a negative electrode busbar connected to negative electrodes of the plurality of power storage modules and led out to the one side of the plurality of power storage modules; and an electrical device electrically connected to both the positive electrode busbar and the negative electrode busbar and disposed on the one side of the plurality of power storage modules.

[0006] In the power storage device described above, the arrangement positions of the positive electrode busbar and the negative electrode busbar connected to the electrodes of the power storage modules are concentrated on one side along the first direction of the power storage modules, so that the power storage modules can be installed in a housing with high space efficiency.

[0007] In the second embodiment of the energy storage device, the plurality of energy storage modules are electrically connected, the positive busbar is connected to the positive terminal of the energy storage module located at one end of the plurality of energy storage modules in the second direction, and the negative busbar is connected to the negative terminal of the energy storage module located at the other end of the plurality of energy storage modules in the second direction.

[0008] In the energy storage device described above, a simple connection structure allows for the arrangement of positive and negative busbars.

[0009] A third embodiment of the energy storage device further includes, in the second embodiment of the energy storage device, a pair of neutral point busbars connected to the positive and negative electrodes of an energy storage module located midway along the second direction of the plurality of energy storage modules, respectively, and drawn out to one side of the energy storage module.

[0010] In the aforementioned energy storage device, the adoption of a neutral point busbar allows for partial discharge or charging of the energy storage module. This enables charge control tailored to the charging power supply and adjustment of the voltage balance of the energy storage cells.

[0011] A fourth embodiment of the energy storage device further includes a noise filter mounted in the third embodiment so as to surround a portion of at least one of the positive electrode busbar, the negative electrode busbar, and the pair of neutral point busbars.

[0012] In the energy storage device described above, it becomes possible to remove noise mixed into the positive and negative busbars with a simple configuration and without affecting the installation space of the energy storage module.

[0013] A fifth embodiment of the energy storage device is the energy storage device of the fourth embodiment, wherein the noise filter includes a first noise filter mounted so as to surround a portion of the positive electrode busbar and a portion of one of the pair of neutral point busbars, and a second noise filter mounted so as to surround a portion of the negative electrode busbar and a portion of the other of the pair of neutral point busbars.

[0014] In the energy storage device described above, it is possible to attach one noise filter to multiple busbars, thus reducing the total number of noise filters compared to attaching one noise filter to each busbar. Furthermore, by aligning the current flow direction of two busbars to which a single noise filter is attached, common-mode noise can be effectively eliminated.

[0015] The sixth embodiment of the energy storage device is the energy storage device of the third embodiment described above, wherein the electrical equipment is positioned to overlap with the positive electrode busbar, the negative electrode busbar, and the neutral point busbar in a third direction that intersects both the first direction and the second direction.

[0016] In the energy storage device described above, electrical equipment can be placed near the positive busbar, negative busbar, and neutral busbar, thus shortening the overall length of the positive and negative busbars. Furthermore, since the electrical equipment is placed at a different height than where the energy storage module, positive busbar, and negative busbar are located, the installation space for the energy storage module is not restricted by the placement of the electrical equipment.

[0017] The seventh embodiment of the energy storage device is an embodiment of the first to sixth embodiments described above, wherein the positive busbar and the negative busbar are connected to terminal blocks that are arranged on one side and are connected to the equipment-side positive busbar and equipment-side negative busbar, respectively.

[0018] In the energy storage device described above, using terminal blocks to connect the positive and negative busbars to electrical equipment makes it easier to handle each component and improves the ease of assembly of each part compared to directly connecting the ends of the positive and negative busbars to the electrical equipment.

[0019] The eighth embodiment of the energy storage device is an energy storage device according to any of the first to seventh embodiments, wherein the plurality of energy storage modules are arranged in four in the second direction.

[0020] In the energy storage device described above, the busbar wiring is simplified by installing four energy storage modules in parallel.

[0021] The ninth embodiment of the energy storage device further includes, in any of the first to eighth embodiments of the energy storage device, an intermodule busbar disposed on the other side of the plurality of energy storage modules along the first direction and electrically connecting adjacent plurality of energy storage modules.

[0022] In the energy storage device described above, adjacent energy storage modules can be electrically connected with a relatively simple structure.

[0023] A power storage device according to the tenth embodiment further includes a housing for housing the plurality of power storage modules in any of the first to ninth embodiments, the housing including a module installation area where the plurality of power storage modules are installed, and a busbar arrangement area provided on one side of the module installation area where the positive electrode busbar and the negative electrode busbar are arranged.

[0024] In the energy storage device described above, the housing protects not only the energy storage module but also the positive and negative busbars from external impacts.

[0025] The above-described energy storage device makes it possible to achieve the desired battery capacity in a space-saving manner.

[0026] This is a schematic perspective view showing an example of an energy storage device according to one embodiment. This is a cross-sectional view of an energy storage module cut along the line A-A shown in Figure 1. This is an exploded perspective view showing an enlarged view of the main part of the energy storage device shown in Figure 1. This is a schematic plan view showing an enlarged view of the busbar arrangement area of ​​the energy storage device shown in Figure 1. This is a perspective view of the main part showing an enlarged view of the positive electrode busbar and one neutral point busbar. This is a perspective view of the main part showing an enlarged view of the negative electrode busbar and the other neutral point busbar.

[0027] This application is based on Japanese Patent Application No. 2025-052184, filed in Japan on March 26, 2025, the contents of which form part of the content of this application. The disclosure can be understood more fully by the following detailed description. Further applications of this application will become clear from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the disclosure and are described for illustrative purposes only, for various changes and modifications will be obvious to those skilled in the art within the spirit and scope of the disclosure from this detailed description. The applicant has no intention of dedicating any of the described embodiments to the public, and any disclosed modifications and alternatives, even those not literally included in the claims, are considered part of the invention under the doctrine of equivalents. Similar reference numbers and names in various drawings indicate similar elements.

[0028] The following describes various embodiments for implementing this disclosure with reference to the drawings. In the following, only the necessary parts for explaining the objectives of this disclosure are schematically shown, and the explanation will primarily focus on the parts necessary for explaining the relevant sections of this disclosure. Any parts omitted from the explanation will be considered to be based on prior art. Furthermore, identical or equivalent components in the drawings are denoted by the same or similar reference numerals, and redundant explanations are omitted. Additionally, if multiple identical or equivalent components are included in the drawings, reference numerals may be assigned to only some of them for clarity.

[0029] Figure 1 is a schematic perspective view showing an example of a power storage device 1 according to one embodiment. In this embodiment, the power storage device (sometimes called a "battery pack") 1 is described as an example of one mounted in an appropriate location on a vehicle, for example, on the floor. In this regard, the arrow FR in Figure 1 corresponds to the front of the vehicle on which the power storage device 1 is mounted, and similarly, the arrow UPR corresponds to the top of the vehicle, and the arrow RH corresponds to the right of the vehicle. In the following description, the direction along the arrow FR will be called the front-rear direction, the direction along the arrow RH will be called the left-right direction, and the direction along the arrow UPR will be called the up-down direction. The aforementioned front-rear direction is an example of the "first direction", the left-right direction is an example of the "second direction", and the up-down direction is an example of the "third direction".

[0030] As shown in Figure 1, the energy storage device 1 according to this embodiment includes a plurality of energy storage modules 10A to 10D, a positive electrode busbar 30 and a negative electrode busbar 40 electrically connected to the plurality of energy storage modules 10A to 10D, and an electrical device 50 electrically connected to both the positive electrode busbar 30 and the negative electrode busbar 40. In addition, the energy storage device 1 according to this embodiment may include a housing 20 in which the plurality of energy storage modules 10A to 10D are installed.

[0031] Each of the energy storage modules 10A to 10D has multiple energy storage cells 11 arranged along the front-to-back direction. In the energy storage device 1 of this embodiment, as shown in Figure 1, an example is provided in which four long energy storage modules 10A to 10D in the front-to-back direction are installed substantially in parallel in the housing 20. Hereafter, for the sake of ease of explanation, the four energy storage modules 10A to 10D described above may be referred to as the "first energy storage module 10A," the "second energy storage module 10B," the "third energy storage module 10C," and the "fourth energy storage module 10D," respectively. In addition, although the four energy storage modules 10A to 10D of this embodiment are shown as being connected in series, they may be partially connected in parallel.

[0032] The four energy storage modules 10A to 10D described above have generally similar configurations, although there are slight differences in the layout of terminals 15F and 15R. Therefore, in order to explain the specific configurations of the four energy storage modules 10A to 10D, the first energy storage module 10A, located on the far right, will be used as a representative example.

[0033] Figure 2 is a cross-sectional view of one energy storage module 10A cut along the line A-A shown in Figure 1. The first energy storage module 10A may consist of a plurality of energy storage cells 11 arranged in a row along the front-to-back direction, end plates 12F and 12R disposed at both ends in the front-to-back direction to support the plurality of energy storage cells 11, and a support 13 that supports the plurality of energy storage cells 11 and the end plates 12F and 12R.

[0034] Multiple energy storage cells 11 can be composed of, for example, rectangular cells that are elongated in the left-right direction. The energy storage cells 11 can be lithium-ion batteries, lithium iron phosphate (LFP) batteries, all-solid-state batteries, etc., but are not particularly limited. A rectangular energy storage cell 11 may have positive electrodes 11A and negative electrodes 11B on its left and right sides. The positive electrodes 11A and negative electrodes 11B of one energy storage cell 11 may be electrically connected to the positive electrodes 11A and negative electrodes 11B of adjacent energy storage cells 11 via a busbar 14 within the module. The arrangement of the positive electrodes 11A and negative electrodes 11B of the energy storage cells 11 can be appropriately changed according to the connection configuration between the energy storage cells 11 and the shape of the energy storage cells 11. Furthermore, in this embodiment, the energy storage cells 11 are arranged such that the positions of the positive electrode 11A and the negative electrode 11B of adjacent energy storage cells 11 are on different sides, and the positive electrode 11A and negative electrode 11B of adjacent energy storage cells 11 are connected by a short internal module busbar 14, thereby illustrating a configuration in which multiple energy storage cells 11 are connected in series. Moreover, the shape of the energy storage cell 11 is not limited to the rectangular shape described above, and cylindrical or pouch-shaped cells can also be used.

[0035] The end plates 12F and 12R may be arranged one at each of the front and rear ends of a plurality of energy storage cells 11 arranged along the front-rear direction, and attached to the support 13 to support the plurality of energy storage cells 11. The end plates 12F and 12R may each be provided with one terminal 15F and one terminal 15R that constitute the positive and negative terminals of the first energy storage module 10A.

[0036] The support 13 can be made of a plate-shaped member that is elongated in the front-to-back direction and has side walls at its left-to-right ends. The support 13 can accommodate a plurality of energy storage cells 11 on its upper part, and its side walls may be shaped to partially cover the module busbars 14 that connect the energy storage cells 11 to each other. In order to stably support the plurality of energy storage cells 11 on the support 13, a cushioning material 16 may be interposed at an appropriate location between the support 13 and the plurality of energy storage cells 11, for example, on the surface on which the energy storage cells 11 are placed.

[0037] Figure 3 is an exploded perspective view showing an enlarged view of the main part of the energy storage device 1 shown in Figure 1. Four energy storage modules 10A to 10D are installed in parallel along the left-right direction in the housing 20. As shown in Figures 1 and 3, the housing 20 may consist of a lower housing 21 on which the four energy storage modules 10A to 10D are mounted in a horizontally aligned state, and an upper housing 22 that covers the upper part of the four energy storage modules 10A to 10D mounted on the lower housing 21. The lower housing 21 and the upper housing 22 may be made of a highly impact-resistant material, such as a metal material. The number of energy storage modules installed in the housing 20 is not limited to four, but an even number is preferable because it makes it easier to identify the neutral point, which will be described later.

[0038] The lower housing 21 may be divided into a module installation area 23 on which the four energy storage modules 10A to 10D are mounted, and a busbar arrangement area 24 on which the positive busbar 30 and the negative busbar 40 are arranged. The module installation area 23 may be composed of a rectangular area to match the shape of the four energy storage modules 10A to 10D. The busbar arrangement area 24 may be composed of an area that is narrowed towards the rear so as to not interfere with the rear wheels of the vehicle on which the energy storage device 1 is mounted, while ensuring space for routing the positive busbar 30 and the negative busbar 40.

[0039] The polarity of terminals 15F and 15R of the four energy storage modules 10A to 10D installed in the module installation area 23 can be adjusted to match the connection configuration between the energy storage modules 10A to 10D. In this embodiment, terminal 15F of the first energy storage module 10A is configured as the negative terminal and terminal 15R as the positive terminal. Similarly, terminal 15F of the second energy storage module 10B is configured as the positive terminal and terminal 15R as the negative terminal, terminal 15F of the third energy storage module 10C is configured as the negative terminal and terminal 15R as the positive terminal, and terminal 15F of the fourth energy storage module 10D is configured as the positive terminal and terminal 15R as the negative terminal.

[0040] The upper housing 22 may have substantially the same shape as the lower housing 21. This upper housing 22 can function as part of the vehicle's floor. In addition, electrical equipment 50 (see Figure 1) may be installed at the rear upper part of the upper housing 22 such that at least a portion of it overlaps with the positive busbar 30, the negative busbar 40, and the neutral busbars 60 and 70 (described later) in a plan view. An opening 25 may be provided in a portion of the upper housing 22 corresponding to the busbar arrangement area 24, penetrating vertically to electrically connect the electrical equipment 50 and the energy storage modules 10A to 10D. Note that in Figure 1, the front portion of the upper housing 22 is omitted to make the structure of the four energy storage modules 10A to 10D easier to see. Also, in Figure 3, the illustration of the electrical equipment 50 is omitted.

[0041] The energy storage device 1 may include a battery management system (BMS) to avoid operational abnormalities such as overcharging and overheating of the energy storage modules 10A to 10D. The aforementioned battery management system may include, for example, electrical equipment 50 connected to the energy storage modules 10A to 10D, and a cooling device (not shown) for cooling the energy storage modules 10A to 10D. The cooling device may consist of a refrigerant passage provided at an appropriate location in the lower housing 21 or the upper housing 22, through which a refrigerant can pass. Examples of refrigerants include air and water.

[0042] The electrical equipment 50 is electrically connected to both the positive busbar 30 and the negative busbar 40, and is positioned on one side, more specifically the rear side, of the multiple energy storage modules 10A to 10D. This electrical equipment 50 may selectively include one or more components, such as a junction box that controls charging and discharging by connecting to the energy storage modules 10A to 10D, a battery ECU that manages the operation of the junction box, an onboard charger (OBC) used during charging, an inverter, or a DC / DC converter. As shown in Figure 1, it is preferable to position the electrical equipment 50 so that at least a portion of it overlaps with the positive busbar 30 and the negative busbar 40 in the vertical direction, as this shortens the overall length of the positive busbar 30 and the negative busbar 40. In addition, the aforementioned arrangement can shorten the overall length of the energy storage device 1 in the front-to-back direction compared to the case where the electrical equipment 50 is installed horizontally alongside the energy storage modules 10A to 10D.

[0043] Figure 4 is a schematic plan view showing an enlarged view of the busbar arrangement area of ​​the energy storage device shown in Figure 1. As shown in Figures 3 and 4, the positive electrode busbar 30 is connected to the positive electrodes of the multiple energy storage modules 10A to 10D and is led out to the busbar arrangement area 24. This positive electrode busbar 30 constitutes part of the wiring for connecting the multiple energy storage modules 10A to 10D and the electrical equipment 50, and may be made of a strip-shaped metal plate. The positive electrode busbar 30 in this embodiment may be provided with contacts 31A and 31B (see Figure 5) at both ends. One of these contacts 31A may be electrically connected to a terminal 15R provided on the rear end plate 12R of the first energy storage module 10A, which is located at one end in the left-right direction, specifically at the right end, of the multiple energy storage modules 10A to 10D that are electrically connected to each other. The terminal 15R of the first energy storage module 10A in this embodiment constitutes the positive electrodes of the four electrically connected energy storage modules 10A to 10D. Furthermore, the portion of the positive electrode busbar 30 excluding the contacts 31A and 31B may be covered by an insulating cover 32 (see Figure 5). Copper, aluminum, brass, or alloys thereof may be used for the various busbars, including the positive electrode busbar 30 used in this embodiment.

[0044] As shown in Figures 3 and 4, the negative electrode busbar 40 is connected to the negative electrodes of the multiple energy storage modules 10A to 10D and is led out to the busbar installation area 24. Similar to the positive electrode busbar 30, this negative electrode busbar 40 also constitutes part of the wiring for connecting the multiple energy storage modules 10A to 10D and the electrical equipment 50, and may be made of a strip-shaped metal plate. The negative electrode busbar 40 in this embodiment may be provided with contacts 41A and 41B at both ends. One of these contacts 41A may be electrically connected to a terminal 15R provided on the rear end plate 12R of the fourth energy storage module 10D, which is located at the other end in the left-right direction, specifically at the left end, among the multiple energy storage modules 10A to 10D that are electrically connected to each other. The terminal 15R of the fourth energy storage module 10D in this embodiment constitutes the negative electrodes of the four electrically connected energy storage modules 10A to 10D. Furthermore, the portion of the negative busbar 40 excluding the contacts 41A and 41B may be covered by an insulating cover 42 (see Figure 6).

[0045] Here, in the power storage device 1 of the present embodiment, it is a matter that should be particularly noted that the positive electrode bus bar 30 and the negative electrode bus bar 40 are arranged behind the plurality of power storage modules 10A to 10D. By adopting the above-described arrangement for the positive electrode bus bar 30 and the negative electrode bus bar 40, the wiring space for each bus bar can be concentrated behind the power storage modules 10A to 10D. When such a configuration is employed, there is no need to secure a space for arranging the positive electrode bus bar 30 and the negative electrode bus bar 40 in the module installation area 23 of the lower housing 21, so the space for installing the power storage modules 10A to 10D can be made compact. In addition, since the positive electrode bus bar 30 and the negative electrode bus bar 40 are collectively arranged, assembly work including connection work between the positive electrode bus bar 30, the negative electrode bus bar 40 and an electric device 50 or the like is facilitated. It is preferable that the positive electrode bus bar 30 and the negative electrode bus bar 40 are fixed to the housing 20 by unillustrated fixing means such as bolts.

[0046] Further, in the power storage device 1, in order to enable partial charging and discharging of the plurality of power storage modules 10A to 10D, a pair of neutral point bus bars 60 and 70 may be connected to a neutral point of the plurality of mutually electrically connected power storage modules 10A to 10D. Similarly to the positive electrode bus bar 30 and the negative electrode bus bar 40, the pair of neutral point bus bars 60 and 70 of the present embodiment are drawn out behind the four power storage modules 10A to 10D and arranged in the bus bar arrangement area 24. The neutral point refers to an intermediate point that bisects the voltage of a plurality of electrically connected power storage modules, or a voltage reference point. The position of the neutral point does not need to strictly bisect the voltage of the plurality of power storage modules, and may be any point that has a voltage intermediate between the voltage of the positive electrode bus bar 30 and the voltage of the negative electrode bus bar 40.

[0047] As shown in Figures 3 and 4, the neutral point bus bars 60 and 70 constitute wiring for connecting the four power storage modules 10A to 10D and the electrical device 50, similarly to the positive electrode bus bar 30 and the negative electrode bus bar 40, and may be formed of, for example, a band-shaped metal plate. The neutral point bus bars 60 and 70 may be respectively provided with contact points 61A, 61B, 71A, and 71B at both ends thereof. One contact point 61A, 71A of each of the neutral point bus bars 60 and 70 is respectively connected to a terminal constituting a neutral point in the four electrically connected power storage modules 10A to 10D. The neutral point of the power storage device 1 of the present embodiment is a contact point at which the second and third power storage modules 10B and 10C are connected to each other. Therefore, one contact point 61A of one neutral point bus bar 60 is electrically connected to a terminal 15R provided on an end plate 12R at the rear side of the second power storage module 10B. Further, one contact point 71A of the other neutral point bus bar 70 is electrically connected to a terminal 15R provided on an end plate 12R at the rear side of the third power storage module 10C. Further, portions of the pair of neutral point bus bars 60 and 70 excluding the contact points 61A, 61B, 71A, and 71B may be respectively covered by insulating covers 62 and 72 (see Figures 5 and 6). The polarities of the terminals 15R and 15R to which the pair of neutral point bus bars 60 and 70 are connected are not particularly limited. For example, the polarities of the respective terminals 15R and 15R of the second and third power storage modules 10B and 10C may be adjusted such that one neutral point bus bar 60 serves as a negative electrode and the other neutral point bus bar 70 serves as a positive electrode in accordance with the polarities of the connected terminals.

[0048] As described above, if the neutral point bus bars 60 and 70 are disposed in the bus bar disposition region 24 similarly to the positive electrode bus bar 30 and the negative electrode bus bar 40, there is no need to separately provide a space for disposing the neutral point bus bars 60 and 70. Therefore, the space for installing the power storage modules 10A to 10D can be maintained compact.

[0049] Figure 5 is an essential part perspective view showing, in an enlarged manner, a positive electrode bus bar and one neutral point bus bar. Further, Figure 6 is an essential part perspective view showing, in an enlarged manner, a negative electrode bus bar and the other neutral point bus bar. Hereinafter, a connection structure between each bus bar and the electrical device 50 will be described with main reference to Figures 3 to 6.

[0050] As shown in Figures 3 and 5, the positive busbar 30 and one neutral busbar 60 are routed to the rear of the first and second energy storage modules 10A and 10B. The negative busbar 40 and the other neutral busbar 70 are routed to the rear of the third and fourth energy storage modules 10C and 10D, as shown in Figures 3 and 6. The other contacts 31B, 41B, 61B, and 71B of these busbars are connected to the electrical equipment 50. However, if each busbar were to be routed directly to the electrical equipment 50, the total length of each busbar would be long, potentially making them difficult to handle and manage. Therefore, in this embodiment, the other contact 31B of the positive busbar 30 is connected to the terminal block 33, and similarly, the other contact 41B of the negative busbar 40 is connected to the terminal block 43, the other contact 61B of one neutral busbar 60 is connected to the terminal block 63, and the other contact 71B of the other neutral busbar 70 is connected to the terminal block 73. The positive busbar 30, the negative busbar 40, and the pair of neutral busbars 60 and 70 are connected to the electrical equipment 50 via these terminal blocks 33, 43, 63, and 73. In Figure 3, among these terminal blocks 33, 43, 63, and 73, the terminal block 43 to which the other contact 41B of the negative busbar 40 is connected and the terminal block 73 to which the other contact 71B of the other neutral busbar 70 is connected are positioned in a location hidden by other components. In the following, terminal blocks 33 and 63 will be described, primarily with reference to Figure 5, as representative examples of each terminal block.

[0051] As shown in Figure 5, terminal blocks 33 and 63 are fixed to the upper part of the other contact 31B of the positive busbar 30 and the other contact 61B of the neutral busbar 60. Various types of terminal blocks can be used for terminal blocks 33 and 63 in this embodiment. Specifically, examples include bolt-type terminal blocks that are fastened and fixed with bolts from above with the contacts of other busbars connected, and clamp-type terminal blocks that elastically fix the contacts of other busbars connected to the terminal block with an elastic body such as a spring. Furthermore, the other two terminal blocks 43 and 73, which are not described or illustrated, may be of the same shape as the terminal blocks 33 and 63 described above.

[0052] As shown in Figures 4 to 6, the energy storage device 1 may include a positive terminal busbar 51, a negative terminal busbar 52, and two neutral point busbars 53 and 54, one end of which is connected to the terminal blocks 33, 43, 63, and 73 described above. The positive terminal busbar 51, the negative terminal busbar 52, and the two neutral point busbars 53 and 54 can be made of strip-shaped metal plates arranged behind the electrical equipment 50. The other ends of the positive terminal busbar 51, the negative terminal busbar 52, and the two neutral point busbars 53 and 54 may be electrically connected to the electrical equipment 50, or more specifically, to a junction box. The equipment-side positive busbar 51 is electrically connected to the positive busbar 30 via terminal block 33, the equipment-side negative busbar 52 is electrically connected to the negative busbar 40 via terminal block 43, and the two equipment-side neutral busbars 53 and 54 may be electrically connected to the two neutral busbars 60 and 70, respectively, via terminal blocks 63 and 73. Furthermore, it is preferable that the terminal blocks 33, 43, 63, and 73 are positioned to overlap the opening 25 in a plan view, so that connections to the equipment-side positive busbar 51, the equipment-side negative busbar 52, and the two equipment-side neutral busbars 53 and 54 can be made over a short distance and the connection work can be made easily.

[0053] By using the terminal blocks 33, 43, 63, and 73 described above, the overall length of each busbar can be shortened, making it easier to handle the busbars. In addition, the connection between the terminal blocks 33, 43, 63, and 73 and the equipment-side positive busbar 51, equipment-side negative busbar 52, and the two equipment-side neutral busbars 53 and 54 can be performed at the same time as mounting the electrical equipment 50 to the top of the housing 20, thus simplifying the assembly process.

[0054] Noise may be introduced into the positive busbar 30, negative busbar 40, and neutral busbars 60 and 70 described above from equipment or contacts connected to each busbar. To remove such noise, it is preferable to attach a noise filter to each busbar. In this embodiment, first and second ferrite cores F1 and F2, as examples of noise filters, are attached so as to surround a part of the positive busbar 30 and a part of one neutral busbar 60, and so as to surround a part of the negative busbar 40 and a part of the other neutral busbar 70.

[0055] As shown in Figure 5, the first ferrite core F1 may be attached in the intermediate portion in the extending direction of the positive electrode busbar 30 and one of the neutral point busbars 60, surrounding the periphery of adjacent portions. Figure 5 illustrates a case where the first ferrite core F1 is a so-called snap-on type ferrite core, which is made openable and closable by dividing a ring-shaped ferrite core into two parts along the axial direction.

[0056] In order to attach the aforementioned first ferrite core F1, it is preferable that the positive busbar 30 and one neutral busbar 60 are shaped so that their intermediate portions are adjacent to each other. In addition, it is preferable to design the wiring shape so that the direction of current flow at the location where the first ferrite core F1 is attached is reversed between the positive busbar 30 and the one neutral busbar 60. When the direction of current flowing through the portion of each busbar to which the first ferrite core F1 is attached is reversed, the common-mode noise contained in each busbar can be effectively removed by the first ferrite core F1.

[0057] The second ferrite core F2 may be mounted in the intermediate portion in the longitudinal direction of the negative electrode busbar 40 and the other neutral point busbar 70, as shown in Figure 6, surrounding the periphery of adjacent portions. Figure 6 illustrates a case where the second ferrite core F2 is a snap-on type ferrite core, similar to the first ferrite core F1 described above.

[0058] In order to attach the aforementioned second ferrite core F2, it is preferable that the negative busbar 40 and the other neutral busbar 70 are shaped so that their intermediate portions are adjacent to each other. In addition, it is preferable to arrange the wiring shape so that the direction of current flow at the location where the second ferrite core F2 is attached is opposite between the negative busbar 40 and the other neutral busbar 70, as this effectively removes common-mode noise contained in each busbar.

[0059] As in this embodiment, when the positive busbar 30, the negative busbar 40, and the pair of neutral busbars 60 and 70 are arranged behind the four energy storage modules 10A to 10D, the installation of the first and second ferrite cores F1 and F2 described above does not affect the installation space of the energy storage modules 10A to 10D. Therefore, it is possible to remove noise mixed into the busbars while making the installation space of the energy storage modules 10A to 10D compact. Furthermore, the fact that the positive busbar 30, the negative busbar 40, and the pair of neutral busbars 60 and 70 are all arranged in the busbar arrangement area 24 facilitates the adoption of noise filters that cover the multiple busbars described above.

[0060] The mounting positions of the first and second ferrite cores F1 and F2 described above can be arbitrarily changed as long as they are in the middle of any of the busbars, and the ferrite cores may also be mounted so as to surround only one busbar. Furthermore, similar ferrite cores can be mounted on the equipment-side positive electrode busbar 51, the equipment-side negative electrode busbar 52, and the two equipment-side neutral point busbars 53 and 54, etc. In addition, although snap-on type ferrite cores are shown as examples for the first and second ferrite cores F1 and F2 in Figures 5 and 6, the shape is not particularly limited, and plate-shaped or ring-shaped ones can also be used.

[0061] As described above, the four energy storage modules 10A to 10D in this embodiment are electrically connected to each other. When making these connections, minimizing the wiring space is important in order to secure ample installation space for the energy storage modules 10A to 10D. In this embodiment, taking the above points into consideration, inter-module busbars 80, 80 for connecting adjacent energy storage modules are included.

[0062] As shown in Figure 1, the intermodal busbars 80, 80 are equipped with contacts 81A, 81B at both ends and may be made of a shorter, strip-shaped metal plate compared to the positive busbar 30 and the negative busbar 40. The intermodal busbars 80, 80 are arranged on the other side, more specifically the front side, along the front-rear direction of the four energy storage modules 10A to 10D, and electrically connect two adjacent energy storage modules. The energy storage device 1 of this embodiment includes two intermodal busbars 80, 80, which electrically connect the first energy storage module 10A to the second energy storage module 10B, and the third energy storage module 10C to the fourth energy storage module 10D, respectively.

[0063] One intermodule busbar 80 may have one contact 81A connected to the front terminal 15F of the first energy storage module 10A, and the other contact 81B connected to the front terminal 15F of the second energy storage module 10B. The other intermodule busbar 80 may have one contact 81A connected to the front terminal 15F of the third energy storage module 10C, and the other contact 81B connected to the front terminal 15F of the fourth energy storage module 10D. In order to shorten the overall length of the intermodule busbars 80, 80, it is preferable that the front terminals 15F of the first energy storage module 10A and the front terminals 15F of the second energy storage module 10B are arranged to be adjacent to each other. Similarly, it is preferable that the front terminals 15F of the third energy storage module 10C and the front terminals 15F of the fourth energy storage module 10D are arranged to be adjacent to each other.

[0064] By employing the inter-module busbars 80, 80 described above, multiple energy storage modules 10A to 10D can be electrically connected with a relatively simple structure. Furthermore, by arranging the inter-module busbars 80, 80 in front of the four energy storage modules 10A to 10D, it becomes possible to connect adjacent energy storage modules 10A to 10D with a small footprint. The method of connecting the second energy storage module 10B and the third energy storage module 10C is not particularly limited, but may be achieved, for example, by the neutral point busbars 60, 70 described above.

[0065] As described above, in the energy storage device 1 according to this embodiment, by consolidating the positive electrode busbar 30 and the negative electrode busbar 40 behind the four energy storage modules 10A to 10D, the need to secure space for arranging the busbars within the installation space of the energy storage modules 10A to 10D is substantially eliminated. As a result, the energy storage modules 10A to 10D can be installed space-efficiently within the aforementioned installation space, specifically the module installation area 23, and an energy storage device 1 with the required battery capacity can be provided in a space-saving manner. Furthermore, because the busbar arrangement positions are consolidated, the energy storage device 1 can be made easy to assemble and maintain.

[0066] As an option, although not shown in this embodiment, low-voltage power supply wire harnesses may be routed to appropriate locations among the multiple energy storage modules 10A to 10D to supply low-voltage power for operating other in-vehicle equipment, etc.

[0067] This disclosure is not limited to the embodiments described above, and can be implemented with various modifications without departing from the spirit of this disclosure. All such modifications are included in the technical concept of this disclosure. Furthermore, unless otherwise specified in the specification, each component of this disclosure is not limited to one, but may exist in multiple forms.

[0068] All documents cited herein, including publications, patent applications, and patents, are incorporated here by reference to the same extent as each document is individually and specifically identified and its contents are described herein.

[0069] The use of nouns and similar demonstrative pronouns in connection with the description of this disclosure (particularly in connection with the following claims) shall be construed as both singular and plural unless otherwise specifically noted herein or if it is clearly inconsistent with the context. The words “equip,” “have,” “include,” and “incorporate” shall be construed as open-ended terms (i.e., “include, but not limited to”) unless otherwise specifically noted herein. The numerical ranges described herein are intended solely as abbreviations for referring individually to each value that falls within that range, unless otherwise specifically noted herein, and each value is incorporated into the specification as if it were individually enumerated herein. All methods described herein can be performed in any appropriate order unless otherwise specifically noted herein or if it is clearly inconsistent with the context. Any examples or illustrative phrases used herein (e.g., “etc.”) are intended solely to better illustrate this disclosure and not to impose any limitations on the scope of this disclosure unless otherwise specifically asserted. Nothing in the specification shall be construed as indicating that any element not described in the claims is essential to the implementation of this disclosure.

[0070] This specification describes preferred embodiments of the Disclosure, including the best mode known to the inventors for carrying out the Disclosure. Those skilled in the art will see, upon reading the above description, that variations of these preferred embodiments will become apparent. The inventors expect that skilled individuals will appropriately apply such variations and that the Disclosure will be carried out in ways other than those specifically described herein. Therefore, this Disclosure includes all modifications and equivalents of the claims appended to this Specification, as permitted by applicable law. Furthermore, any combination of the above elements in all variations is incorporated into this Disclosure unless specifically noted herein or is obviously inconsistent with the context.

Claims

1. An energy storage device comprising: a plurality of energy storage cells arranged along a first direction and a plurality of energy storage modules arranged along a second direction intersecting the first direction; a positive electrode busbar connected to the positive electrodes of the plurality of energy storage modules and drawn out to one side of the plurality of energy storage modules along the first direction; a negative electrode busbar connected to the negative electrodes of the plurality of energy storage modules and drawn out to the one side of the plurality of energy storage modules; and an electrical device electrically connected to both the positive electrode busbar and the negative electrode busbar and located on the one side of the plurality of energy storage modules.

2. The energy storage device according to claim 1, wherein the plurality of energy storage modules are electrically connected, the positive busbar is connected to the positive terminal of the energy storage module located at one end of the plurality of energy storage modules in the second direction, and the negative busbar is connected to the negative terminal of the energy storage module located at the other end of the plurality of energy storage modules in the second direction.

3. The energy storage device according to claim 2, further comprising a pair of neutral point busbars connected to the positive and negative electrodes of an energy storage module located midway along the second direction of the plurality of energy storage modules, respectively, and drawn out to one side of the energy storage module.

4. The energy storage device according to claim 3, further comprising a noise filter mounted so as to surround a portion of at least one of the positive busbar, the negative busbar, and the pair of neutral busbars.

5. The energy storage device according to claim 4, wherein the noise filter comprises a first noise filter mounted so as to surround a portion of the positive busbar and a portion of one of the pair of neutral busbars, and a second noise filter mounted so as to surround a portion of the negative busbar and a portion of the other of the pair of neutral busbars.

6. The energy storage device according to claim 3, wherein the electrical equipment is positioned to overlap with the positive electrode busbar, the negative electrode busbar, and the neutral point busbar in a third direction that intersects both the first and second directions.

7. The energy storage device according to claim 1, wherein the positive busbar and the negative busbar are connected to terminal blocks that are arranged on one side and are connectable to the equipment-side positive busbar and equipment-side negative busbar, respectively, which are connected to the electrical equipment.

8. The energy storage device according to claim 1, wherein the plurality of energy storage modules are arranged in a four-way pattern along the second direction.

9. The energy storage device according to claim 1, further comprising an intermodule busbar disposed on the other side of the plurality of energy storage modules along the first direction and electrically connecting adjacent plurality of energy storage modules.

10. The energy storage device according to claim 1, further comprising a housing for housing the plurality of energy storage modules, wherein the housing comprises a module installation area where the plurality of energy storage modules are installed, and a busbar arrangement area provided on one side of the module installation area where the positive electrode busbar and the negative electrode busbar are arranged.

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