Assembled battery

Abstract

To provide a reliable battery by preventing high current from flowing between a battery cell and a battery pack in a salt test and suppressing rapid reactions due to high current.SOLUTION: In order to achieve the first object, an assembled battery 100 includes: a plurality of battery cells (single cells) 101; a first termination member 102 that holds the plurality of battery cells 101 from a first end side of a stacking direction; a second termination member 103 that holds the plurality of battery cells from the other end side of the stacking direction; and a coupling member 104 that connects the first termination member 102 and the second termination member 103. The coupling member 104 holding the battery cells 101 in the stacked direction and a connection member connected to a battery pack are isolated from each other.SELECTED DRAWING: Figure 15

Description

Technical Field

[0001] The present invention relates to a battery pack in which a plurality of battery cells are stacked.

Background Art

[0002] As this type of battery pack, there is disclosed one having a plurality of stacked battery cells, a bus bar case fixed to the plurality of battery cells, and a plurality of covers that cover and protect the bus bar case (Patent Document 1).

[0003] Patent Document 2 describes a configuration in which a connecting fixture for connecting a plurality of battery cells such as iron is tightened in one direction by a connecting fixture formed of a metal such as a steel plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] A configuration in which a plurality of battery packs are arranged in a metal container is called a battery pack. When a test is performed by immersing this battery pack in salt water, there is a risk of a short circuit occurring between the battery pack and the battery pack, resulting in a rapid reaction. The first problem of the present invention is to suppress a large current from flowing between the battery cell and the container of the battery pack through the salt water even when the battery pack is immersed in salt water, suppress a rapid reaction, and provide a highly reliable battery.

[0006] In the assembled battery described in Patent Document 1, when the number of battery cells is changed according to requirements, the overall length changes, so the length in the stacking direction of the battery cells such as the bus bar case and the gas hose and the position of the electrode terminal, which is the power extraction site, are changed.

[0007] A second problem of the present invention has been made to solve such problems, and an object is to provide an assembled battery capable of minimizing changes in components even when the number of battery cells constituting the battery changes.

Means for Solving the Problems

[0008] The main means for solving the first problem is as follows. That is, a battery body in which a plurality of single cells are stacked, and a pair of end members arranged on both sides of the battery body in the stacking direction and having an insulating material, and arranged on both side surfaces of the single cells of the battery body in the stacking direction of the single cells, and connected to the end members, and having a pair of side plates made of a metal material, and the end member includes a fastening portion that houses a fastening member that fastens the assembled battery to an object to be placed, and the fastening portion and the side plate are electrically non-connected. An assembled battery characterized by this.

[0009] The main means for solving the second problem is as follows. That is, a plurality of stacked batteries, a first end member that holds the plurality of single cells from one end side in the stacking direction, a second end member that holds the plurality of single cells from the other end side in the stacking direction, and a connecting member that connects the first end member and the second end member, and the first end member protrudes a predetermined length from the connection position in the stacking direction with the connecting member toward the single cell, and the predetermined length is equal to or greater than the thickness of the single cell in the stacking direction. An assembled battery characterized by this.

Effects of the Invention

[0010] According to the present invention, even when the battery pack is immersed in salt water, it is possible to mitigate the current generated between the cell and the battery pack container and suppress the occurrence of a rapid reaction. Further, even if a rapid reaction occurs, its influence can be contained within the battery pack. Also, even when the number of batteries changes, the change in components can be minimized. Further features related to the present invention will become apparent from the description in this specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0011]

Figure 1

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BEST MODE FOR CARRYING OUT THE INVENTION

[0012] Next, the present invention will be described with reference to Example 1 and Example 2. Example 1 is an invention related to a configuration in which even when the number of single cells changes, changes in components can be minimized. Example 2 provides a configuration that can relax the current generated between the battery cell and the battery container and suppress a rapid reaction even when the assembled battery is immersed in salt water.

EXAMPLE

[0013] FIG. 15 is a plan view conceptually showing an embodiment of the assembled battery of the present invention.

[0014] The assembled battery 100 includes a plurality of battery cells (single cells) 101, a first end member 102 that holds these plurality of battery cells 101 from one end side in the stacking direction, a second end member 103 that holds them from the other end side in the stacking direction, and a connecting member 104 that connects the first end member 102 and the second end member 103. And the first end member 102 protrudes by a predetermined length L4 from the connection position P in the stacking direction with the connecting member 104 toward the battery cell 101, and this predetermined length L4 is equal to or greater than the thickness L2 of the battery cell 101 in the stacking direction. Note that the reference sign P2 in FIG. 15 represents the connection position of the second end member 103 in the stacking direction with the connecting member 104.

[0015] According to the configuration of the assembled battery 100 shown in FIG. 15, by using an end member having a thickness different from that of the first end member 102 instead of the first end member 102, it is possible to obtain assembled batteries with the same outer shape but different numbers of battery cells 101. For example, by using an end member that is thinner than the predetermined length L4 by which the first end member 102 protrudes by the thickness of one battery cell, it is possible to form an assembled battery with a specification in which the number of battery cells 101 is increased by one. Further, for example, by using an end member that is thicker than the predetermined length L4 by which the first end member 102 protrudes by the thickness of one battery cell, it is possible to form an assembled battery with a specification in which the number of battery cells 101 is decreased by one.

[0016] These assembled batteries only differ in the number of battery cells, and since the same connecting member 104 and second end member 103 are used, the overall size of the assembled battery does not change, and the outer shapes are the same as each other. Therefore, it is not necessary to newly manufacture each component such as a bus bar case, a gas hose, and a plurality of covers according to the number of cells of the battery cell, and they can be shared. Further, even if the number of cells of the battery cell is changed, the assembly process and jigs do not change, and it is not necessary to change the settings of the manufacturing equipment, so the equipment can be shared. Also, there is no problem that the types of components increase and the management man-hours increase.

[0017] Furthermore, for example, when installing assembled batteries with different numbers of battery cells in two electric vehicles of the same vehicle type but different battery specifications, it is possible to install them without changing the vehicle body structure for installing the assembled batteries, or with only minor changes, and a common vehicle platform can be used. Also, common vehicle parts can be used without changing the routing of electrical wiring or the routing of the exhaust gas passage for the exhaust gas discharged from the battery cells. In addition, when it becomes necessary to increase the number of battery cells installed in a vehicle due to a vehicle model change, or when it becomes possible to reduce the number of battery cells installed in a vehicle due to an improvement in battery performance, it is possible to easily respond without changing the overall size of the assembled battery.

[0018] FIG. 16 is a plan view conceptually showing another embodiment of the assembled battery of the present invention.

[0019] The assembled battery 200 includes a plurality of stacked battery cells (single cells) 201, a spacer 202 stacked together with these plurality of battery cells 201, and a holding member 203 that holds the plurality of battery cells 201 and the spacer 202 along the stacking direction. The holding member 203 holds the plurality of battery cells 201 and the spacer 202 at a total length L1 of a fixed value defined along the stacking direction. And the thickness L3 of the spacer 202 in the stacking direction of the spacer 202 is equal to or greater than the thickness L2 of the battery cell 201 in the stacking direction.

[0020] According to the configuration of the assembled battery 200 shown in FIG. 16, by simply using a spacer with a thickness different from that of the spacer 202 instead of the spacer 202, it is possible to obtain an assembled battery with the same outer shape but different numbers of battery cells 201. For example, by using a spacer that is thinner than the thickness L3 of the spacer 202 by the thickness of one battery cell, it is possible to form an assembled battery with a specification in which the number of battery cells 201 is increased by one. Also, for example, by using a spacer that is thicker than the thickness L3 of the spacer 202 by the thickness of one battery cell, it is possible to form an assembled battery with a specification in which the number of battery cells 201 is decreased by one.

[0021] These battery packs are the same as the embodiment shown in FIG. 15, except that the number of battery cells is different, the overall size of the battery pack remains unchanged, and the outer shapes are identical to each other. Therefore, the same effects as the embodiment shown in FIG. 15 can be obtained.

[0022] Hereinafter, the battery packs 10 according to the first embodiment, the battery packs 10A according to the second embodiment, the battery packs 10B according to the third embodiment, the battery packs 10C according to the fourth embodiment, and the battery packs 10D according to the fifth embodiment to which the battery pack according to the present invention is applied will be described with reference to the drawings.

[0023] (First Embodiment) First, the battery cell 1 constituting the battery pack 10 according to the first embodiment will be described with reference to the drawings. As shown in FIG. 1, the battery cell 1 includes a battery can 2, a battery lid 3, a positive electrode terminal 4, a negative electrode terminal 5, a gas discharge valve 6, a liquid injection plug 7, an electrolytic solution (not shown), a charge / discharge element, and an insulating case. A rechargeable secondary battery such as a lithium ion secondary battery is used for the battery cell 1. The battery cell 1 of the first embodiment corresponds to a single cell of the battery pack according to an embodiment of the present invention.

[0024] The battery can 2 has a rectangular parallelepiped shape with one end of the internal space open, and is made of aluminum or an aluminum alloy. The battery can 2 has a pair of opposing side plates 2a with a large area, a pair of opposing side plates 2b with a small area, and a bottom plate 2c on the side opposite to the opening. In the internal space of the battery can 2, the charge / discharge element is housed in a state covered with an insulating case, and the electrolytic solution is injected. The positive electrode of the charge / discharge element is connected to the positive electrode terminal 4, and the negative electrode of the charge / discharge element is connected to the negative electrode terminal 5.

[0025] The battery lid 3 has the same rectangular flat plate shape as the bottom plate 2c, is made of aluminum or an aluminum alloy, and closes the opening of the battery can 2. The battery lid 3 is joined to the opening of the battery can 2 by a joining means such as laser welding. The battery lid 3 is formed with a liquid injection hole (not shown) penetrating therethrough, the electrolytic solution is injected through the liquid injection hole, and the liquid injection hole is closed with the liquid injection plug 7.

[0026] In the central portion of the battery cover 3, a gas discharge valve 6 is provided. The gas discharge valve 6 cracks when the battery cell 1 generates heat due to an abnormality such as overcharging and generates gas, and the pressure inside the battery can 2 rises to a predetermined pressure, and discharges the gas from the inside of the container to reduce the pressure inside the battery can 2.

[0027] In addition, through holes (not shown) are formed at one end and the other end of the battery cover 3, and the positive electrode terminal 4 and the negative electrode terminal 5 are attached. The portions of the positive electrode terminal 4 and the negative electrode terminal 5 that are exposed outside the battery cover 3 are each formed in a rectangular parallelepiped shape and have flat top surfaces. The electric power generated by the battery cell 1 is supplied to an external device via the positive electrode terminal 4 and the negative electrode terminal 5, or the electric power generated externally via the positive electrode terminal 4 and the negative electrode terminal 5 is supplied to a charge-discharge element for charging.

[0028] Next, the assembled battery 10 will be described. The assembled battery 10 is mounted, for example, on a hybrid vehicle driven by an internal combustion engine and a motor or an electric vehicle driven by a motor, and is used as a drive source for the motor. As shown in FIG. 2, the assembled battery 10 has a block 11 and a bus bar case assembly 12.

[0029] (Block 11) As shown in FIGS. 3 and 4, Block 11 has a plurality of stacked battery cells 1, spacers 21, a first end spacer 22, a second end spacer 23, a pair of side rails 24, 25, a pair of end plates 26, 27, and a plurality of bolts 28. Block 11 has a stacked structure of battery cells 1 and spacers 21, with each component integrated. Block 11 has a constant length with the pair of side rails 24, 25 and the bus bar case assembly 12. When using a regular-sized end member (not shown) instead of the second end spacer 23, it can hold the maximum number of battery cells 1. When using the second end spacer 23, it can hold a number of battery cells 1 less than the maximum number. That is, by changing the second end spacer 23 to one with a different thickness, the number of battery cells 1 in Block 11 can be changed without changing the length of Block 11.

[0030] The spacer 21 is made of an insulating synthetic resin. As shown in FIG. 3, it is alternately sandwiched between adjacent battery cells 1 and stacked in the X direction together with the battery cells 1. Each spacer 21 has recesses on both sides corresponding to the shape of the battery cell 1, and holds the battery cell 1 by the recesses, regulating the Y direction and the Z direction. Also, the spacer 21 is provided with claw portions at the upper part in the Z direction and is adapted to fit with claw portions provided on the bus bar case 35 described later.

[0031] The first end spacer 22 is made of an insulating synthetic resin harder than the spacer 21 and is disposed opposite to the battery cell 1 located at one end in the stacking direction. The first end spacer 22 has a recess corresponding to the shape of the battery cell 1 on the opposing surface facing the battery cell 1, holds the battery cell 1 by the recess, and regulates the Y direction and the Z direction. Also, on the side of the first end spacer 22 facing the end plate 27, a fixing bolt hole 22a and a negative electrode connection terminal 22b are provided. Further, a fixing bolt hole 22d for fixing each component is formed at the upper part in the Z direction of the first end spacer 22.

[0032] The second end spacer 23 is made of a synthetic resin that has insulation properties and is harder than the spacer 21, and is disposed adjacent to the battery cell 1 located at the other end in the stacking direction. As shown in FIG. 3, the second end spacer 23 has a plurality of rectangular cutout holes formed therein, preventing the occurrence of indentation, so-called sink marks, after molding and deformation. The second end spacer 23 has a recess corresponding to the battery cell 1 on the opposing surface facing the battery cell 1, and holds the battery cell 1 by the recess, regulating the Y direction and the Z direction.

[0033] On the side of the second end spacer 23 facing the end plate 26, a fixing bolt hole 23a, a positive electrode connection terminal 23b, and a gas discharge duct fixing hole 23d are formed. Note that the first end spacer 22 and the second end spacer 23 of the first embodiment correspond to the end members of the assembled battery according to an embodiment of the present invention. The fixing bolt holes 22a and 23a correspond to the fixing portions for fixing the assembled battery to the installation target. The positive electrode connection terminal 23b and the negative electrode connection terminal 22b correspond to connection terminals that are electrically connected to the single battery and electrically connected to the outside of the assembled battery. The gas discharge duct fixing hole 23d corresponds to the fixing portion of the gas discharge duct for discharging the gas that has come out of the single battery to the outside of the assembled battery.

[0034] In the second end spacer 23 of the first embodiment, the distance from the fixing bolt hole 23a to the opposing surface 23f facing the battery cell is equal to or greater than the thickness of the battery cell 1 in the stacking direction. In the present embodiment, the second end spacer 23 is formed to be thicker in the stacking direction by the thickness of n stacked battery cells 1 than the regular-sized end member (regular end member) used when the number of cells is x. Here, x is the maximum number of battery cells 1 that can be stacked within the block 11, and n is an integer less than the number x of stacked battery cells 1, and is preferably an even number in order to minimize changes in components. That is, n and x are in the relationship of n < x. Also, the thickness of n stacked battery cells 1 includes the thickness of the spacers sandwiched between the battery cells 1.

[0035] The length of the second end spacer 23 from each element of the fixing bolt hole 23a, the positive electrode connection terminal 23b, and the gas discharge duct fixing hole 23d to the facing surface 23f facing the battery cell 1 is larger by an integer multiple of the thickness of the battery cell 1 compared to the regular end member. For example, when the thickness of the second end spacer 23 is thicker by an amount equal to twice the thickness of the battery cell 1 than the regular end member, a battery pack with two fewer cells can be made compared to when using the regular end member. In the block 11 where the number of cells is 24 when using the regular end member, by using the second end spacer 23 instead of the regular end member, a block 11 with 22 cells can be formed.

[0036] The total length L24 of the regular end member, the 24 battery cells 1 and the spacers, the second end spacer 23 formed to be thicker by the width of two battery cells 1, and the total length L22 of the 22 battery cells 1 and the spacers are the same length (L24 = L22). And the positions of the fixing bolt hole 23a, the positive electrode connection terminal 23b, and the gas discharge duct fixing hole 23d of the second end spacer 23 are the same as those of the regular end member. As a result, in the block 11, even if the number of cells is reduced by two and changed to 22, components other than the second end spacer 23 do not require design changes such as dimensions and shapes and can be used as they are.

[0037] In this embodiment, the case where the second end spacer 23 is thicker than the thickness of one battery cell 1 has been described. However, a regular end member may be used instead of the second end spacer 23, and a first end spacer 22 formed to be thicker than the thickness of one battery cell 1 may be used. Also, for both the first end spacer 22 and the second end spacer 23, ones each made thicker by at least the thickness of one battery cell 1 may be used. In this case, the first end spacer 22 of the first embodiment corresponds to the first end plate or the second end plate of the battery pack according to an embodiment of the present invention, and the second end spacer 23 corresponds to the first end plate or the second end plate.

[0038] The side rail 24 is formed of a metal material. As shown in FIG. 3, it has a rail body 24c extending in the X direction and bent portions 24b that are bent in the Y direction at both ends of the rail body 24c and face each other. Each bent portion 24b is provided with a fixing hole 24a penetrating in the X direction. The bent portions 24b are arranged to face each other from the outside in the stacking direction with respect to the first end spacer 22 and the second end spacer 23, and cover a part of the first end spacer 22 and a part of the second end spacer 23.

[0039] The side rail 24 holds and binds the first end spacer 22, the plurality of battery cells 1, the plurality of spacers 21, and the second end spacer 23 in a state of being pressed in the stacking direction. A bolt 28 is inserted into the fixing hole 24a of the bent portion 24b of the side rail 24 and fixed to the end plates 26 and 27. This bolt 28 is often formed of metal.

[0040] The side rail 24 has a length capable of stacking 22 battery cells 1 when the second end spacer 23 is used. The side rail 25 has a shape similar to that of the side rail 24 and is a mirror image thereof. The side rail 25 is formed of the same metal material as the side rail 24 and has the same function as the side rail 24. The side rail 25 is arranged to face the side rail 24 in the Y direction with the stacked battery cells 1 interposed therebetween, and has a rail body 25c extending in the X direction and bent portions 25b that are bent in the Y direction at both ends of the rail body 25c and face each other. The bent portion 25b has a fixing hole 25a through which the bolt 28 is inserted. The pair of side rails 24 and 25 in the first embodiment respectively correspond to the side members of the assembled battery according to one embodiment of the present invention.

[0041] The end plate 26 is formed of a plate-shaped metal material, so-called sheet metal, and is disposed adjacent to the second end spacer 23 as shown in FIG. 3. The end plate 26 has a flat portion 26a in which a positioning through hole for the second end spacer 23 is formed, and a fixing portion 26b for fixing the side rails 24 and 25. The fixing portion 26b has a fixing hole 26c through which a bolt 28 is inserted. The fixing portion 26b has a step recessed in the stacking direction with respect to the flat portion 26a, and is configured such that when the bent portions 24b and 25b of the side rails 24 and 25 are fastened with the bolt 28, the head of the bolt does not protrude from the surface of the flat portion 26a. A nut is attached to the fixing portion 26b. The fixing portion 26b of the first embodiment corresponds to a connection portion with a side member of the assembled battery according to an embodiment of the present invention.

[0042] The end plate 27 is formed in the same manner as the end plate 26 and is disposed adjacent to the first end spacer 22 as shown in FIG. 4. The bent portions 24b and 25b of the end plate 27, the side rail 24, and the side rail 25 are fastened by a bolt 28. The pair of end plates 26 and 27 of the first embodiment respectively correspond to end members of the assembled battery according to an embodiment of the present invention.

[0043] (Bus bar case assembly 12) As shown in FIG. 3, the bus bar case assembly 12 includes a bus bar 31, a harness, a gas discharge duct 234, a plurality of covers 34, and a bus bar case 35. The bus bar case assembly 12 has functions such as electrical connection between terminals of the battery cell 1 or with a controller, monitoring of voltage and temperature, and discharge of gas.

[0044] As shown in FIG. 5, the bus bar 31 has an inter-cell bus bar 31a, a negative electrode bus bar 31b, and a positive electrode bus bar 31c, and each component is housed in a bus bar case 35. The inter-cell bus bar 31a is configured to electrically connect the positive electrode terminal 4 and the negative electrode terminal 5 of the battery cell 1. The negative electrode bus bar 31b is connected to the second end spacer 23, and the positive electrode bus bar 31c is connected to the first end spacer 22. Note that the negative electrode bus bar 31b has a shape that is longer in the stacking direction of the battery cells 1 as compared with the case of the regular end member.

[0045] The harness has a terminal portion, a wire portion, a temperature sensor portion, and a connector portion. The terminal portion is electrically connected to the bus bar 31 and the harness via the wire portion. The temperature sensor portion is in contact with the battery cover 3, measures the temperature of the battery cover 3, and outputs the measurement result. The connector portion is connected to each component and connects each component to a controller (not shown). Each component is stored in the bus bar case 35.

[0046] The gas discharge duct 334 has a gas discharge port 233, and isolates and collects the gas discharged from the gas discharge valve 108b at the center in the Y direction of the bus bar case 30 and discharges it from the gas discharge port 233. The gas discharge duct 234 is fixed to the female threads of the first end spacer 22 and the second end spacer 23 by screws arranged at both ends in the X direction. The plurality of covers 34 have a function of insulating and protecting the components of the bus bar case assembly 12, and are arranged so as to cover the bus bar 31 and the harness. Each cover 34 is fitted and fixed to the bus bar case 35.

[0047] The bus bar case 35 has a plurality of frames arranged in the stacking direction of the battery cells 1, and is configured to store the inter-cell bus bar 31a, the negative electrode bus bar 31b, and the positive electrode bus bar 31c in the frames, respectively. The bus bar case 35 has a plurality of claw portions, and the bus bar case assembly 12 is fixed to the block 11 by fitting the claw portions with the claw portions provided at the upper portions in the Z direction of each spacer 21, the first end spacer 22, and the second end spacer 23 of the block 11.

[0048] The effects of the assembled battery 10 according to the first embodiment will be described.

[0049] The assembled battery 10 according to the first embodiment has a second end spacer 23. When the number of cells is x, the second end spacer 23 is formed to be thicker in the stacking direction by the thickness corresponding to the stacking of n battery cells 1 than the regular end member used. The total lengths of the side rails 24 and 25 are the same before and after the change regardless of the change in the number of battery cells 1 in the block 11. In addition, in the second end spacer 23 and the regular end spacer, the positions of the fixing bolt holes 23a, the positive electrode connection terminals 23b, and the gas discharge duct fixing holes 23d are also the same.

[0050] As a result, it is possible to cope with the change in the number of battery cells 1 only by changing two components, i.e., the second end spacer 23 and the negative electrode bus bar 31b that constitutes the bus bar case assembly 12, and it is possible to obtain the effect that no change is required for the other components of the assembled battery 10. Note that by extending a part of the negative electrode bus bar 31b, no change is required for the bus bar case 35. In the assembled battery 10 according to the present embodiment, it is possible to easily provide a combination of an assembled battery of 24 battery cells 1 in the block 11 and an assembled battery of 22 battery cells 1.

[0051] In a conventional assembled battery, when the number of battery cells is changed, it is necessary to newly manufacture each component of the assembled battery according to the number of cells. In this case, there are problems that the assembly process and jigs are changed, and the settings of the manufacturing equipment also need to be changed each time, making it difficult to share the equipment, and the types of components increase and the management man-hours also increase. On the other hand, in the assembled battery 10 according to the first embodiment, even when the number of battery cells constituting the battery changes, the change in components can be minimized. In addition, jigs and equipment can be shared to minimize process changes, and an increase in the management man-hours of components can be suppressed, so that the conventional problems can be solved.

[0052] The assembled battery 10 according to the first embodiment has been described in the case where the end plate 26 is made of sheet metal and the thickness of the second end spacer 23 is increased. The assembled battery according to the first embodiment of the present invention may be configured with a structure other than the structure of the first embodiment. Hereinafter, the assembled batteries 10A according to the second embodiment, 10B according to the third embodiment, 10C according to the fourth embodiment, and 10D according to the fifth embodiment, which are configured with structures other than the structure of the first embodiment, will be described with reference to the drawings. For the components similar to those of the assembled battery 10 according to the first embodiment, the same reference numerals will be used and the detailed description thereof will be omitted.

[0053] (Second Embodiment) FIG. 6 is a perspective view of the assembled battery according to the second embodiment, and FIG. 7 is an exploded perspective view of the assembled battery according to the second embodiment. What is characteristic in this embodiment is that the fixed bolt hole 26Ab and the gas discharge duct fixing hole 26Ae are provided in the end plate 26A instead of the end spacer 23A.

[0054] As shown in FIG. 6, the assembled battery 10A according to the second embodiment is composed of a block 11A and a bus bar case assembly 12A. As shown in FIGS. 7 and 8, the block 11A includes a plurality of battery cells 1, a plurality of spacers 21, a first end spacer 22A, a second end spacer 23A, a pair of side rails 24 and 25, a pair of end plates 26A and 27A, and a plurality of bolts 28.

[0055] The first end spacer 22A has a flat opposing surface that faces the end plate 27A on one side in the stacking direction, and a recess corresponding to the battery cell 1 is formed on the other side in the stacking direction. The battery cell 1 is held by the recess, and it has a configuration that regulates the Y direction and the Z direction. The second end spacer 23A has a flat opposing surface that faces the end plate 26A on the other side in the stacking direction, and a recess corresponding to the battery cell 1 is formed on one side in the stacking direction. The battery cell 1 is held by the recess, and it has a configuration that regulates the Y direction and the Z direction.

[0056] The second end spacer 23A has a distance between the positive electrode connection terminal 26Ac and the facing surface 23Af facing the battery cell 1, that is, the thickness of the second end spacer 23A, which is equal to or greater than the thickness of the battery cell 1 in the stacking direction. In the present embodiment, the second end spacer 23A is formed to be thicker in the stacking direction by the number of n stacked battery cells 1 than a regular-sized end member (regular end member) used when the number of cells is x. As the regular end member, one having the same shape as the first end spacer 22A can be used.

[0057] For example, in the block 11 where the maximum number of battery cells 1 is 24, when it is desired to change to a configuration with a decrease of two cells, the second end spacer 23A that is thicker by the amount of two stacked battery cells 1 is used. Since the second end spacer 23A has a thickness corresponding to the reduction in the number of two battery cells 1 and the spacer 21 interposed therebetween, the position of the end plate 26A remains the same whether the number of battery cells 1 is 24 or 22. As a result, in the block 11, even when the number of cells is changed from 24 to 22, components other than the second end spacer 23 do not require design changes such as dimensions and shapes and can be used as they are.

[0058] The end plate 26A is formed of a plate-shaped member made of aluminum die-cast, whereas the end plate 26 in the first embodiment is formed of a sheet metal member. The end plate 26A is arranged to face the second end spacer 23A in the X direction, which is the stacking direction. The end plate 26A has a fixing portion 26Aa in which fixing bolt holes for fixing the side rails 24 and 25 are formed.

[0059] The end plate 26A is formed with a fixing bolt hole 26Ab and a gas discharge duct fixing hole 26Ae. The fixing bolt hole 26Ab in the second embodiment corresponds to a fixing portion for fixing the assembled battery to an installation target in the assembled battery according to an embodiment of the present invention, and the gas discharge duct fixing hole 26Ae corresponds to a discharge portion for discharging gas that has come out of the single cell to the outside of the assembled battery.

[0060] The end plate 27A is formed in the same manner as the end plate 26A and is disposed adjacent to the first end spacer 22A as shown in FIG. 8. The end plate 27A is formed with a fixing bolt hole 27Ab for fixing the assembled battery 10A, a negative electrode connection terminal 27Ad, and a gas discharge duct fixing hole 27Ae. The bent portions 24b and 25b of the end plate 27A, the side rail 24, and the side rail 25 are configured to be fastened by bolts 28. Note that the pair of end plates 26A and 27A of the second embodiment respectively correspond to the end members of the assembled battery according to one embodiment of the present invention.

[0061] As shown in FIGS. 7 and 8, the bus bar case assembly 12A includes a bus bar 31A, a harness, a gas discharge duct 234 having a gas discharge port 233, a plurality of covers 34A, and a bus bar case 35A. When the number x of battery cells 1 is decreased by two and changed to (x - 2), the change is only in the negative bus bar 31Ab of the bus bar 31A as in the first embodiment. The harness, the cover 34A, and the bus bar case 35A have the same functions as the harness, the cover 34, and the bus bar case 35 of the first embodiment.

[0062] In the assembled battery 10A according to the second embodiment, the changes associated with the change in the number x of battery cells 1 are only in the second end spacer 23A and the negative bus bar 31Ab, and the same effects as those of the assembled battery 10 according to the first embodiment can be obtained.

[0063] (Third Embodiment) FIG. 9 is an exploded perspective view of an assembled battery according to the third embodiment. What is characteristic in this embodiment is that the thickness of the second end spacer 23B is thinner than that of the second end spacer 23A of the second embodiment, and the thickness of the end plate 26B is larger than that of the end plate 26A of the second embodiment.

[0064] As shown in Fig. 9, the assembled battery 10B according to the third embodiment is composed of a block 11B and a bus bar case assembly 12A identical to that of the second embodiment. The block 11B is formed by die-casting the end plate 26B and the end plate 27A in the same manner as the block 11A of the assembled battery 10A of the second embodiment. However, different from the block 11A, the shape of the second end spacer 23B is different from the shape of the end plate 26B.

[0065] The second end spacer 23B has a regular size with no extended thickness. A recess corresponding to the shape of the battery cell 1 is formed on one surface in the stacking direction, and the surface facing the end plate 26B on the other side in the stacking direction is formed flat.

[0066] The distance from the fixed bolt hole 26Bb to the opposing surface 26Bf facing the second end spacer 23B of the end plate 26B is equal to or greater than the thickness of the battery cell 1 in the stacking direction. In this embodiment, the end plate 26B is formed to be thicker in the stacking direction by the thickness of n stacked battery cells 1 than the regular-sized end member (regular end member) used when the number of cells is x. The end plate 26B is arranged adjacent to the second end spacer 23B. The end plate 26B has a fixing portion 26Ba formed with fixing bolt holes for fixing the side rails 24 and 25. The end plate 26B is formed with a fixed bolt hole 26Bb, a positive electrode connection terminal 26Bc, a negative electrode connection terminal 26Bd, and a gas discharge duct fixing hole 26Be.

[0067] For example, in block 11 where up to 24 battery cells 1 can be stacked, when the number of cells is reduced by 2 to 22, an end plate 26B formed to be thicker by the thickness of two stacked battery cells 1 compared to the regular end member is used. As a result, the positions of the fixing bolt holes 26Bb, the positive electrode connection terminal 26Bc, the negative electrode connection terminal 26Bd, and the gas discharge duct fixing holes 26Be of the end plate 26B can remain the same without change between the cases where the number of battery cells 1 is 24 and 22. Consequently, in block 11, even when the number of cells is changed from 24 to 22, components other than the end plate 26B do not require design changes such as in dimensions and shape and can be used as they are.

[0068] (Fourth Embodiment) FIG. 10 is an exploded perspective view of the assembled battery according to the fourth embodiment. What is characteristic in this embodiment is that the block 11C uses dummy cells 1C for a part of the plurality of battery cells 1.

[0069] As shown in FIG. 10, the assembled battery 10C according to the fourth embodiment has a block 11C. The second end spacer 23C and the end plate 26, which are end members of the block 11C, are of regular sizes used when the maximum number of cells is x.

[0070] The dummy cell 1C has the same outer dimensions as the battery cell 1 and is formed of a material such as an aluminum alloy. n dummy cells 1C are stacked adjacent to the battery cell 1. For example, in the block 11 serving as a reference where the number of battery cells 1 is stacked at x, when the number of cells x is reduced by 2 and changed to (x - 2), two dummy cells 1C are stacked instead. As shown in FIG. 10, the two dummy cells 1C are arranged to face each other with the spacer 21 in between.

[0071] In the assembled battery 10C according to the fourth embodiment, the changes associated with the change in the number x of cells of the battery cell 1 are only the dummy cell 1C and the negative electrode bus bar 31b, and the same effects as those of the assembled battery 10 according to the first embodiment can be obtained. For example, in the block 11 in which 24 battery cells 1 are stacked, when the number of cells is decreased by 2 and changed to 22, by inserting two dummy cells, the position of the fixing bolt hole 23Ca of the second end spacer 23C, the positive electrode connection terminal 23Cb, and the gas discharge duct fixing hole 23Cd remains the same regardless of whether the number of battery cells 1 is 24 or 22. Therefore, no design changes such as dimensions and shapes are required for each component, and they can be used as they are.

[0072] (Fifth Embodiment) FIG. 11 is a perspective view of the assembled battery according to the fifth embodiment, and FIG. 12 is an exploded perspective view of the assembled battery according to the fifth embodiment. What is characteristic in this embodiment is that an extension spacer 21D is provided at an intermediate position in the stacking direction of the plurality of battery cells 1.

[0073] As shown in FIGS. 11 and 12, the assembled battery 10D has a block 11D. The block 11D is configured by stacking a plurality of battery cells 1. An extension spacer 21D is interposed at an intermediate position in the stacking direction of the plurality of battery cells 1.

[0074] The extension spacer 21D has a thickness equivalent to n battery cells 1. For example, in the block 11 in which a maximum of x battery cells 1 can be stacked, when the number of cells is decreased by 2 to (x - 2), the extension spacer 21D formed to be as thick as two stacked battery cells 1 is used. The extension spacer 21D is located at an intermediate position in the stacking direction where the battery cells 1 and the spacers 21 are alternately stacked, and is displaced to the side of one end rather than the central portion in the stacking direction.

[0075] The plurality of battery cells 1 of the block 11D are divided into two in the stacking direction by the extension spacer 21D. Then, bus bars are attached so as to straddle the extension spacer 21D and are connected to each other.

[0076] The extended spacer 21D may be composed of two or more extended spacers. In this case, the total thickness of the widths of the two or more extended spacers is formed to be thicker than the thickness of the battery cell 1. The extended spacer 21D is formed to be thicker than the thickness of the other spacers 21. Also, the extended spacer 21D may be disposed at a position other than the central portion. For example, one or two extended spacers may be arranged adjacent to the battery cell 1 closest to the second end spacer 23C or the first end spacer 22.

[0077] According to the assembled battery 10D according to the present embodiment, even if the number of battery cells 1 in the block 11D is reduced, by using the extended spacer 21D having the reduced thickness, the positions of the fixing bolt holes 23Ca of the second end spacer 23C, the positive electrode connection terminal 23Cb, and the gas discharge duct fixing holes 23Cd do not change and can be made the same. Therefore, design changes such as dimensions and shapes for each component are not required and can be used as they are.

[0078] The assembled batteries 10 according to the first embodiment to the assembled batteries 10D according to the fifth embodiment are used as a power supply device in which a single assembled battery or a plurality of assembled batteries are arranged and electrically connected.

[0079] Next, power supply devices 40 and 50 in which a plurality of assembled batteries 10E are arranged linearly in the stacking direction of the battery cells 1 will be described with reference to FIGS. 13 and 14.

[0080] FIG. 13 is a configuration diagram of a power supply device including two assembled batteries in which a plurality of battery cells are stacked, and FIG. 14 is a configuration diagram of a power supply device including four assembled batteries in which a plurality of battery cells are stacked.

[0081] As shown in FIG. 13, the power supply device 40 includes two battery packs 10E and a bus bar 40a that electrically connects the two battery packs 10E. The battery pack 10E is configured in the same manner as the battery pack 10 according to the first embodiment. The bus bar 40a connects the positive electrode Pe of one battery pack 10E and the negative electrode Ne of the other battery pack 10E that are arranged to face each other. The two battery packs 10E are arranged in series in the closest state by the bus bar 40a.

[0082] Note that the battery pack 10E corresponds to the first battery pack or the second battery pack of the battery pack according to an embodiment of the present invention. The stacking direction of the battery cells 1 corresponds to the first direction, and the bus bar 40a corresponds to the first bus bar. The power supply device 40 may arrange the two battery packs 10E in a direction orthogonal to the stacking direction of the respective battery cells 1. In this case, the orthogonal direction corresponds to the second direction of the battery pack according to an embodiment of the present invention. The battery pack 10E has a first end spacer 22E formed to be as thick as two battery cells 1. As a result, the battery packs 10 and 10E have the same overall length.

[0083] With this configuration, the power supply device 40 can minimize the length of the bus bar 40a. When the power supply device 40 is mounted on a vehicle, it is arranged so as to straddle the left-right direction of the vehicle. For example, one battery pack 10E is arranged under the left seat LS, and the other battery pack 10E is arranged under the right seat RS. Therefore, the effect that the weight balance of the vehicle becomes uniform left and right is obtained.

[0084] Next, as shown in FIG. 14, the power supply device 50 includes two power supply devices 40, a plate-like structure K fixed to the floor surfaces of two vehicle bodies (not shown), and a plurality of bolts (not shown) for fixing the two power supply devices 40 to the structure K. The two power supply devices 40 are arranged in parallel such that the stacked battery cells 1 face each other. The centers of gravity G1, G2, G3, and G4 as the first centers of gravity of the respective battery packs 10E indicated by circles are located at positions away from the center portions in the stacking direction of the stacked battery cells 1 with respect to the bus bar 40a, and are set at the center portions in the width direction of the battery pack 10E orthogonal to the stacking direction.

[0085] The center of gravity G0 as the second center of gravity of the entire structure of the power supply device 50 is located at the center in the vehicle width direction. When mounted on the vehicle, the power supply device 50 is arranged so as to straddle the left and right directions of the vehicle as shown by the dashed line. For example, the left side portion of the power supply device 50 is located below the left seat LS, and the right side portion of the power supply device 50 is located at the portion of the right seat RS. Therefore, the center of gravity G0 of the power supply device 50 is located at the central portion between the left and right seats. Note that the front-rear, left-right directions indicate the directions as seen from the vehicle occupant when the occupant is seated on the seat.

[0086] With this configuration, since the power supply devices 50 are arranged in parallel, space saving is achieved, and an effect that the overall weight balance becomes uniform is obtained.

[0087] Based on the description up to this point with reference to FIGS. 1 to 16, the following expressions are possible.

[0088] <Expression 1> A plurality of single cells to be stacked, A first end member that holds the plurality of single cells from one end side in the stacking direction, A second end member that holds the plurality of single cells from the other end side in the stacking direction, A connecting member that connects the first end member and the second end member, having, The first end member protrudes a predetermined length from the connection position in the stacking direction with the connecting member toward the single cell, The predetermined length is not less than the thickness of the single cell in the stacking direction, and the assembled battery is characterized in this.

[0089] <Expression 2> A plurality of single cells to be stacked, A spacer stacked together with the plurality of battery cells, A holding member that holds the plurality of battery cells and the spacer along the stacking direction, having, The holding member holds the plurality of battery cells and the spacer at a total length of a constant value defined along the stacking direction, The laminated battery is characterized in that the thickness of the spacer in the stacking direction of the spacer is equal to or greater than the thickness in the stacking direction of a single battery.

[0090] <Expression 3> A laminated battery in which a plurality of single batteries are laminated, A pair of end members disposed opposite to both sides in the stacking direction of the plurality of single batteries, A pair of side members that are separated from each other in a direction orthogonal to the stacking direction and extend along the stacking direction to connect the pair of end members to each other, The end member, An end plate connected to the side member, and an end spacer disposed between the end plate and the single battery, The end plate has any one of a connection portion with the side member, a fixing portion for fixing the laminated battery to an installation target, a connection terminal that is electrically connected to the single battery and electrically connected to the outside of the laminated battery, and a discharge portion for discharging gas emitted from the single battery to the outside of the laminated battery. The laminated battery is characterized in that, in the stacking direction of the single battery, the length from any one of the above configurations to the facing surface facing the single battery is greater than the thickness of the single battery.

[0091] <Expression 4> A laminated battery in which a plurality of single batteries are laminated, A pair of end members disposed opposite to both sides in the stacking direction of the plurality of single batteries, A pair of side members that are separated from each other in a direction orthogonal to the stacking direction and extend along the stacking direction to connect the pair of end members to each other, The end member, An end plate connected to the side member, and an end spacer disposed between the end plate and the single battery, The end spacer has any one of a connection portion with the side member, a fixing portion for fixing the assembled battery to an installation target, a connection terminal that is electrically connected to the single battery and is electrically connected to the outside of the assembled battery, and an exhaust portion for exhausting gas emitted from the inside of the single battery to the outside of the assembled battery. An assembled battery, characterized in that, in the stacking direction of the single batteries, the length from any one of the above configurations to the opposing surface facing the single battery is greater than the thickness of the single battery.

[0092] <Expression 5> The pair of side members has a length for stacking and arranging x single batteries when a regular end member is arranged at an end on one side in the stacking direction of the plurality of single batteries. The assembled battery according to Expression 3 or 4, characterized in that at least one of the pair of end members has a thickness in the stacking direction that is thicker than the regular end member by the thickness of n (n < x) single batteries.

[0093] <Expression 6> The assembled battery according to any one of Expressions 3 to 5, characterized in that the length greater than the thickness of the single battery is an integer multiple of the thickness of the single battery.

[0094] <Expression 7> The end member has a plurality of members arranged in the stacking direction of the single batteries. The assembled battery according to any one of Expressions 3 to 6, characterized in that the sum of the lengths in the stacking direction of two or more of the plurality of members is greater than the thickness in the stacking direction of the single battery.

[0095] <Expression 8> A plurality of single batteries to be stacked, End members arranged at both ends in the stacking direction of the single batteries, And side members arranged along the stacking direction of the single batteries and connected to the end members. The end member is A first end member arranged at one end in the stacking direction, And a second end member arranged at the other end in the stacking direction. The assembled battery is characterized in that, in the stacking direction of the single battery, the first end member has a length equal to or greater than the sum of the length of the second end member and the thickness of the single battery.

[0096] <Expression 9> The end member includes an end plate connected to the side member, and an end spacer disposed between the single battery closest to the end plate in the stacking direction of the single battery and the end plate, and has the end plate or the end spacer includes a first end plate or a first end spacer disposed at one end, and a second end plate or a second end spacer disposed at the other end, and the first end plate has a length equal to or greater than the sum of the length of the second end plate and the thickness of the single battery in the stacking direction of the single battery, or the first end spacer has a length equal to or greater than the sum of the length of the second end spacer and the thickness of the single battery, and the assembled battery according to Expression 8 is characterized in that.

[0097] <Expression 10> A power supply device applied to a vehicle including a plurality of assembled batteries according to Expression 8 or 9, wherein the assembled battery includes a first assembled battery and a second assembled battery having a plurality of single batteries stacked in a first direction along the stacking direction of the single batteries of the first assembled battery, the second assembled battery is disposed on a straight line along the first direction or in a second direction orthogonal to the straight line along the first direction, in the first direction, an end on the side where the first end member or the first bus bar of the first assembled battery is located is closer to the end on the side where the first end member or the first bus bar of the second assembled battery is located than the other end, and the power supply device is characterized in that.

[0098] <Expression 11> A power supply device applied to a vehicle including the assembled battery according to Expression 8 or 9 and a structure provided adjacent to the assembled battery, The spacer is lighter than the single battery and is disposed on the side of one end rather than the central portion in the stacking direction of the plurality of single batteries stacked in the stacking direction, The first center of gravity of the assembled battery is located on the side of the other end facing the one end in the stacking direction rather than the central portion, The assembled battery and the structure in the state of being disposed in the vehicle are arranged in the vehicle such that the second center of gravity constituted by the assembled battery and the structure in the state of being disposed in the vehicle is located closer to the center in the vehicle width direction intersecting the traveling direction of the vehicle than the first center of gravity of the assembled battery in the state of being disposed in the vehicle. A power supply device characterized by that.

[0099] <Expression 12> A plurality of single batteries to be stacked, A spacer stacked together with the plurality of single batteries, End members located at both ends of the stacked plurality of single batteries and the spacer, And a side member located along the stacking direction of the single battery and connected to the end member. The side member holds the end member, the plurality of single batteries, and the spacer at a total length of a certain value defined along the stacking direction, The end member has any one of a connection portion with the side member, a fixing portion for fixing the assembled battery to an installation target, a connection terminal for electrically connecting to the single battery and electrically connecting to the outside of the assembled battery, and a discharge portion for discharging gas emitted from the inside of the single battery to the outside of the assembled battery. The thickness in the stacking direction of the spacer located between any one of the configurations and the single battery farthest from any one of the configurations and having the single batteries disposed on both sides is a thickness equal to or greater than the thickness in the stacking direction of any one of the single batteries. An assembled battery characterized by that.

[0100] <Expression 13> A plurality of single batteries to be stacked, A plurality of spacers laminated together with the plurality of single cells; End members located at both ends of the laminated plurality of single cells and the spacers; A side member located along the stacking direction of the single cells and connected to the end member, and having: The side member holds the end member, the plurality of single cells, and the spacers over the entire length of a fixed value defined along the stacking direction; Among the plurality of spacers, the thickness of the first spacer in the stacking direction is greater than the thickness of the second spacer in the stacking direction; The first spacer is disposed on a side of one end rather than the central portion in the stacking direction of the plurality of single cells arranged in the stacking direction; The second spacer is disposed on a side of the other end facing the one end in the stacking direction rather than the central portion, and a difference between the thickness of the first spacer in the stacking direction and the thickness of the second spacer in the stacking direction is equal to or greater than the thickness of the single cell in the stacking direction. A battery pack characterized by this.

[0101] <Expression 14> The spacer has two or more spacers between adjacent single cells in the stacking direction, or has two or more spacers adjacent to the single cell at the stacking end; The battery pack according to Expression 12 or Expression 13, characterized in that a total length of the thicknesses of the two or more spacers in the stacking direction is equal to or greater than the thickness of the single cell in the stacking direction.

[0102] <Expression 15> The first spacer has a thickness in the stacking direction that is equal to or greater than the thickness of any of the single cells in the stacking direction; The first spacer is on a plane orthogonal to the stacking direction; The battery pack according to Expression 12 or Expression 13, wherein the first width in the first direction is less than or equal to the first width in the second spacer, or the second width in the second direction orthogonal to the first direction is less than or equal to the second width of the second spacer.

[0103] Although the embodiment of Example 1 of the present invention has been described in detail above, this example is not limited to the above-described embodiment, and various design changes can be made without departing from the spirit of the present invention described in the claims. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

Example

[0104] In general, a battery pack has a structure in which a block obtained by stacking a plurality of battery cells is held by a metal plate. Then, a plurality of battery packs are stored and fixed in a metal container and incorporated into an automobile or the like as a battery pack.

[0105] In a conventional assembled battery, a metal side plate is connected to a metal end plate disposed at the outermost part of a cell stack, and has a structure for tightly holding a plurality of battery cells. And the end plate is fixed to a metallic container connected to the ground to constitute a battery pack. The side plate is electrically conductive with the container. However, if the side plate remains exposed metal, when the battery pack is immersed in salt water, a short circuit may occur between the side plate connected to the ground and the battery cell through the salt water, leading to a rapid reaction. To address this, conventionally, an insulation treatment has been performed on the side plate to prevent a short circuit between the battery cell and the side plate. However, there is a problem that performing the insulation treatment on the side plate increases the cost.

[0106] To solve such problems, in this embodiment, the metallic container of the battery pack connected to the ground and the side plate are kept insulated from each other, and even when the battery pack is immersed in salt water, the current between the battery cell and the side plate is relaxed to suppress a rapid reaction.

[0107] This embodiment can be applied not only to the structure of Embodiment 1 but also to a normal assembled battery. Therefore, the following description will explain the case where this embodiment is applied to a normal assembled battery. The specific configuration is as follows. That is, by changing the component for fixing the assembled battery to the metallic container from a metallic end spacer to a resin end spacer, the insulation between the container of the battery pack and the battery cell is maintained. Such a configuration is also described, for example, in FIGS. 3 and 4 and paragraphs 0024 to 0027 of Embodiment 1. A metallic collar is inserted into the resin end spacer, and the assembled battery is fastened to the container of the battery pack with bolts passing through the collar.

[0108] A plurality of battery cells are stacked in a first direction, and this stack is held so as to be surrounded by two end plates and two side plates. That is, the end plates and the side plates hold and fix the plurality of battery cells by bolting the stack of battery cells in the first direction. The side plate is electrically insulated from the container formed of metal. That is, since the end spacer is formed of an insulator, the side plate or the container of the battery pack is insulated from the battery cells. Therefore, even when a battery pack having a plurality of assembled batteries is immersed in salt water, the current flowing between the battery cells and the container of the battery pack is mitigated, and a rapid reaction due to the flow of a large current is also suppressed.

[0109] In addition, in order to ensure insulation between the side plate and the battery cells, protruding ribs are formed on the spacers inserted between the battery cells so that the distance between the side plate and the battery cells can be maintained.

[0110] The specific configuration of Example 2 will be described below with reference to the drawings. FIG. 17 is an external view of the assembled battery 10 in Example 2. The assembled battery 10 shown in FIG. 17 is substantially the same in configuration and appearance as that shown in FIG. 2 etc. in Example 1. However, the configuration of Example 2 can be used not only for the assembled battery 10 in Example 1, but also for a normal assembled battery 10 that does not use the configuration of Example 1. Therefore, the configuration of the assembled battery 10 shown below is not particularly limited to the configuration of Example 1.

[0111] FIG. 18 is an exploded perspective view showing the state in which the assembled battery 10 of FIG. 17 is disassembled into a block 11 and a bus bar case assembly 12. FIG. 19 is an exploded perspective view of the block 11. As shown in FIG. 19, the longitudinal direction of the block 11 is defined as the X direction (or the stacking direction), the vertical direction is defined as the Z direction, and the direction orthogonal to the X direction and the Z direction is defined as the Y direction.

[0112] Note that the harness 32 has a terminal portion, a wire portion, a temperature sensor portion, and a connector portion. The terminal portion is electrically connected to the bus bar and the harness via the wire portion. The temperature sensor portion is in contact with the battery cover, measures the temperature of the battery cover, and outputs the measurement result. The connector portion is connected to each component and connects each component to a controller (not shown). The harness of Example 1 can be the same.

[0113] As shown in FIGS. 17 to 19, the assembled battery 10 includes a plurality of battery cells 101 and a block 11 having a mechanism for integrating them, and a bus bar case assembly 12 including harnesses for electrically connecting the terminals of the battery cells 101 and monitoring voltage and temperature.

[0114] In FIG. 19, the block 11 is arranged in a form in which a pair of side plates 120, the battery cells 101, and a plurality of spacers 121 are alternately stacked in the X direction in the Y direction. Next to the battery cells 101 located at both ends in the X direction, a negative electrode end spacer 122 on the -X direction side, a positive electrode end spacer 123 on the +X direction, end plates 124 arranged on both sides thereof, and a plurality of bolts 125 are provided.

[0115] The materials of the spacer 121, the N end spacer (negative electrode end spacer) 122, and the P end spacer (positive electrode end spacer) 123 are insulating resins. The plurality of stacked battery cells 101 are held by grooves corresponding to the battery cells 101 provided in the spacer 121, the N end spacer 122, and the P end spacer 123, and regulate the X direction and the Y direction.

[0116] The end plate 124 is a steel plate on a rectangular flat plate extending in the Y direction, and two nuts are provided in the X direction by caulking or the like.

[0117] The side plate 120 is a steel plate having a flange extending in the Y direction, a hole shape penetrating in the X direction, and a shape in which a wide surface facing the Y direction is largely opened.

[0118] A plurality of battery cells 101, spacers 121, N-end spacers 122, and P-end spacers 123 are sandwiched between a pair of end plates 124, and these laminates are held and fixed in a compressed state by a pair of side plates 120. The side plates 120 are fastened and fixed to nuts provided on the end plates 124 by bolts 125.

[0119] Figure 20 is an external perspective view of the N-end spacer 122. In the N-end spacer 122, a metallic collar 126 having a through-hole 126a for a through-bolt and a metallic collar 127 having a through-hole 127a are arranged to house and fix the assembled battery 10 that houses the block 11 in the container of the battery pack (hereinafter also referred to as the container). When fixing the block 11 to the container, bolts are passed through the through-holes 126a and 127a of the collars 126 and 127 and fastened.

[0120] Figure 21 is a side view of the block 11. Figure 22 is a cross-sectional view taken along the line A-A of Figure 21. In Figure 22, the side plate 120 and the end plate 124 are in contact with each other at the insulating resin portion of the N-end spacer 122 and are not in contact with the collars 126 and 127. That is, the side plate 120 and the end plate 124 are electrically insulated from the collars 126 and 127. Therefore, the side plate 120 is also insulated from the container of the battery pack.

[0121] Figure 23 is a front view of the spacer 121. The spacer 121 has ribs 121a, 121b, 121c, and 121d, and as shown by x and y in Figure 22, it is designed to keep the distance between the battery cell 101 and the side plate 120 at a constant interval. That is, the ribs 121a, 121b, 121c, and 121d can set the necessary interval so that the battery cell 101 and the side plate 120 can maintain sufficient insulation from each other.

[0122] With the above configuration, even when the battery pack is immersed in salt water, since the side plate 120 is not connected to the ground, it is possible to mitigate the current flowing through the salt water between the battery cells 101 and suppress a rapid reaction. Further, a connection portion 121e is formed on the upper side facing the bus bar case assembly 12. For example, a protrusion on a claw is formed. The opposing bus bar case 35 is provided with a fixing portion for fixing the connection portion 121e. In the present embodiment, an example in which the connection portion 121e is provided on each spacer is shown, but the present invention is not limited thereto, and spacers provided with the connection portion 121e via an interval may be arranged. This contributes to fixing the block 11 and the bus bar case assembly 12. The resin spacer 121 is fitted and fixed to the resin bus bar case 35. Thereby, unnecessary electrical conduction between the assembled battery and surrounding members can be suppressed.

[0123] FIG. 24 is a cross-sectional view showing another configuration in which the battery body is tightened in the stacking direction by the side plate 120 and the end spacer 122. FIG. 24 is a schematic cross-sectional view and corresponds to the vicinity of the N end spacer 122 in FIG. 22. FIG. 24 has a structure in which the end spacer 122 and the side plate 120 formed of an insulating resin are directly connected. That is, in the end plate 122, an insert nut is embedded in advance in the hole into which the bolt 125 is inserted. Then, the side plate 120 and the end plate 124 are directly fastened in the X direction by bolts.

[0124] In FIG. 24, in the end spacer 122, a metallic collar 126 having a through-hole 126a for a through-bolt and a metallic collar 127 having a through-hole 127a are arranged to house and fix the assembled battery in the container of the battery pack. The collars 126 and 127 having the same potential as the container and the side plate 120 are insulated. Therefore, the side plate 120 is insulated from the container of the battery pack. Further, as shown in FIG. 19, the side plate 120 is also in an insulated state from both the battery pack and the battery cell 101. Therefore, even when the assembled battery is immersed in salt water, the current flowing between the battery cell 101 and the side plate 120 can be mitigated, and the occurrence of a rapid reaction can be suppressed.

[0125] FIG. 25 is a cross-sectional view showing still another configuration in which the battery body is fastened in the stacking direction by the side plate 120 and the end spacer 122. FIG. 25 is a schematic cross-sectional view, but corresponds to the vicinity of the end spacer 122 in FIG. 22. In FIG. 25, the end plate 122 is formed not of a metal plate but, for example, by aluminum die-casting. According to die-casting, the end plate 124 can be formed into a relatively free shape. In FIG. 25, the end plate 124 is arranged outside the end spacer 122. In FIG. 25, in the end plate 124, the portion where the bolt 125 is screwed in has a thick plate thickness, and a female screw is directly formed in this portion. Therefore, the end plate 124 and the side plate 120 can be fastened without separately forming a nut or the like by caulking or the like. In FIG. 25, the end plate 124 and the side plate 120 are fastened in the X direction by the bolt 125.

[0126] Also in Fig. 25, in order to house and fix the assembled battery in the container of the battery pack, a metallic collar 126 having a through-hole 126a for a through-bolt and a metallic collar 127 having a through-hole 127a are arranged. The collars 126 and 127 having the same potential as the container and the side plate 120 are insulated from each other. Therefore, even when the assembled battery is immersed in salt water, the current flowing between the battery cell 101 and the side plate 120 can be mitigated, and the occurrence of a rapid reaction can be suppressed.

[0127] Fig. 26 is a cross-sectional view showing still another configuration in which the battery body is fastened in the stacking direction by the side plate 120 and the end spacer 122. Fig. 26 is a schematic cross-sectional view, but corresponds to the vicinity of the end spacer 122 in Fig. 22. Fig. 26 is the same as Fig. 25 in that the end plate 124 is formed of, for example, an aluminum die-cast instead of a metal plate. The difference between Fig. 26 and Fig. 25 is that the end plate 124 is arranged inside the end spacer 122. According to die-casting, the end plate 124 can be formed into a relatively free shape, so that the shape can be changed according to the shape inside or outside the end spacer 124.

[0128] In Fig. 26, in the end plate 124, the portion where the bolt 125 is screwed in has a thick plate thickness, and a female screw is directly formed in this portion. Therefore, the end plate 124 and the side plate 120 can be fastened without separately forming a nut or the like by caulking or the like. In Fig. 26, the end plate 124 and the side plate 120 are fastened in the X direction by a bolt 125 so as to sandwich the end spacer 122.

[0129] Also in Fig. 26, in order to house and fix the assembled battery in the container of the battery pack, a metallic collar 126 having a through-hole 126a for a through-bolt and a metallic collar 127 having a through-hole 127a are arranged. The collars 126 and 127 having the same potential as the container and the side plate 120 are insulated. Therefore, even when the assembled battery is immersed in salt water, the current flowing between the battery cell 101 and the side plate 120 can be relaxed, and the occurrence of a rapid reaction can be suppressed.

Explanation of Signs

[0130] 1: Battery cell (single cell), 2: Battery can, 10, 10A, 10B, 10C, 10D, 10E: Assembled battery, 11: Block, 12: Bus bar case assembly, 21: Spacer (second spacer), 21D: Extension spacer (first spacer), 22: First end spacer (regular end member), 22a, 23a, 23Ca, 26Ab, 26Bb, 27Ab: Fixed bolt hole, 23, 23A, 23B, 23C: Second end spacer (end member), 24, 25: Side rail (side member), 26, 26A, 26B, 27, 27A: End plate (end member), 26a: Flat part, 26b, 26Aa, 26Ba, 27Aa: Fixed part, 28: Bolt, 31, 40a: Bus bar, 233: Gas discharge part, 34: Cover, 35: Bus bar case, 40, 50: Power supply device, G0: Center of gravity (second center of gravity), G1, G2, G3, G4: Center of gravity (first center of gravity), 101: Battery cell (single cell), 120: Side plate, 121: Spacer, 121a: Rib, 121b: Rib, 121c: Rib, 121d: Rib, 122: N end spacer, 123: P end spacer, 124: End plate, 125: Bolt, 126: Collar, 126a: Through-hole, 127: Collar, 127a: Through-hole

Claims

1. a battery body in which a plurality of single cells are stacked; a pair of end members arranged on both sides of the battery body in the stacking direction of the battery body and having an insulating material; a battery pack having a pair of side plates arranged on both side surfaces of the single cells of the battery body in the stacking direction of the single cells, connected to the end members, and having a metal material; the end member includes a fastening portion that houses a fastening member for fastening the battery pack to an object to be placed; the fastening portion and the side plate are electrically non-connected; A battery pack characterized by the above.

2. The end member is a pair of end plates formed of a metal material and having a connection portion with the side plate; a pair of end spacers formed of an insulating material and having the fastening portion, the battery pack according to claim 1.

3. The end plate and the side plate are co-fastened so as to clamp the plurality of single cells in the stacking direction at the connection portion arranged outside the end spacer when viewed in the stacking direction of the single cells, The side plate is characterized in that it is not electrically conductive with the fastening member, the battery pack according to claim 2.

4. The end plate and the side plate are co-fastened so as to clamp the plurality of single cells in the stacking direction at the connection portion arranged inside the end spacer when viewed in the stacking direction of the single cells, and the side plate is not electrically conductive with the fastening member, the battery pack according to claim 2.

5. The end member has a pair of end spacers connected to the side plate; the side plate is co-fastened with the pair of end spacers and the plurality of single cells so as to clamp them in the stacking direction; The side plate is characterized in that it is not electrically conductive with the fastening member, the battery pack according to claim 1.

6. The fastening member is a metal bolt, the battery pack according to any one of claims 1 to 5.

7. The side surface of the single cell of the battery body in the stacking direction and the side plate are arranged with a gap therebetween and are electrically insulated from each other, the battery pack according to any one of claims 1 to 6.

8. The end member is an end plate connected to the side member and an end spacer arranged between the end plate and the single cell; The end plate has any one of a connection portion with the side member, a fixing portion for fixing the assembled battery to an installation target, a connection terminal that is electrically connected to the single battery and electrically connected to the outside of the assembled battery, and a discharge portion for discharging gas that has come out of the single battery to the outside of the assembled battery. The assembled battery according to any one of claims 1 to 7, characterized in that, in the stacking direction of the single batteries, the length from any one of the above configurations to the facing surface facing the single battery is greater than the thickness of the single battery.

9. The end member is an end plate connected to the side member, and an end spacer disposed between the end plate and the single battery, The end spacer has any one of a connection portion with the side member, a fixing portion for fixing the assembled battery to an installation target, a connection terminal that is electrically connected to the single battery and electrically connected to the outside of the assembled battery, and a discharge portion for discharging gas that has come out of the single battery to the outside of the assembled battery. The assembled battery according to any one of claims 1 to 8, characterized in that, in the stacking direction of the single batteries, the length from any one of the above configurations to the facing surface facing the single battery is greater than the thickness of the single battery.

10. The end member is a first end member disposed at one end in the stacking direction, and a second end member disposed at the other end in the stacking direction. The assembled battery according to any one of claims 1 to 9, characterized in that, in the stacking direction of the single batteries, the first end member has a length equal to or greater than the combined length of the length of the second end member and the thickness of the single battery.

11. The end member is an end plate connected to the side member, and an end spacer disposed between the single battery closest to the end plate in the stacking direction of the single batteries and the end plate. The end plate or the end spacer has a first end plate or a first end spacer disposed at one end, and a second end plate or a second end spacer disposed at the other end. The first end plate has a length equal to or greater than the combined length of the length of the second end plate and the thickness of the single battery in the stacking direction of the single batteries. Alternatively, the battery pack according to any one of claims 1 to 10, wherein the first end spacer has a length equal to or greater than the combined length of the second end spacer and the thickness of the single battery.

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