WO2020026961A1

WO2020026961A1 - Battery system, electric vehicle provided with battery system, and power storage device

Info

Publication number: WO2020026961A1
Application number: PCT/JP2019/029336
Authority: WO
Inventors: 忍寺内
Original assignee: 三洋電機株式会社
Priority date: 2018-07-31
Filing date: 2019-07-26
Publication date: 2020-02-06
Also published as: JP2021180063A

Abstract

In order to reduce weight while reducing component cost and to hold cells while compressing the cells with a high pressure, this battery system is provided with: a cell laminate (2) obtained by laminating a plurality of rectangular cells (1); and binding materials (3) for binding the cell laminate (2) in the direction in which the cells (1) are laminated, and fixing each of the cells (1) in a compressed state. The binding materials (3) are flexible, looped-shaped string materials (30).

Description

Battery system, electric vehicle including battery system, and power storage device

The present invention relates to a battery system in which a plurality of rectangular battery cells are stacked to form a battery stack, and the battery stack is pressed and fixed in a pressurized state, an electric vehicle including the battery system, and a power storage device.

A large number of prismatic batteries are stacked to form a battery stack, a pair of end plates are arranged on both end surfaces of the battery stack, and the end plates are connected with bind bars, and the stacked square batteries are pressed. Fixed battery systems have been developed. (See Patent Document 1)

バッテリ In this battery system, it is necessary to pressurize and fix the battery cells with a considerable pressure. If the pressing force of the battery cell is weak, the rectangular battery relatively moves due to vibration or the like, causing various adverse effects. Further, in order to prevent the rectangular battery from swelling due to charge and discharge, it is necessary to press and fix the rectangular battery with a considerable pressing force. In the battery system having this structure, in order to fix each prismatic battery in a pressurized state, end plates are arranged on both end surfaces of the battery stack, and a pair of end plates are pressed by a press machine. The bind bar is connected to the end plate. The end plates connected by the bind bars are held at regular intervals to fix each prismatic battery in a pressurized state at a predetermined pressure.

JP 2011-60623 A

In the battery system described above, since the battery cells are pressed and fixed with a considerable pressure, a considerably strong tensile force acts on the bind bar. For example, in a battery system that supplies electric power to a motor that drives an electric vehicle, a tensile force of several tons acts on a bind bar. Since high-strength steel or a thick metal plate is used for the binding bar in order to withstand a strong tensile force, the cost of parts of the binding bar is high and there is a problem that the binding bar becomes heavy.

The present invention has been developed to solve the above-mentioned drawbacks. An important object of the present invention is to provide a technique capable of holding a battery cell by applying a high pressure while reducing the weight of parts while reducing the cost of parts.

A battery system according to an aspect of the present invention includes a battery stack formed by stacking a plurality of rectangular battery cells, and binding the battery stack in a stacking direction of the battery cells, and fixing each battery cell in a pressurized state. And the binding material is a flexible loop-shaped string material.

Furthermore, an electric vehicle including a battery system including the components of the above-described embodiments is a vehicle including the battery system, a running motor supplied with power from the battery system, and the battery system and the motor. The vehicle includes a main body and wheels driven by the motor to drive the vehicle main body.

Further, a power storage device including a battery system including the components of the above aspects includes the battery system, and a power supply controller that controls charging and discharging of the battery system, wherein the power supply controller is configured to control the rectangular shape by external power. The battery cell can be charged and the battery cell is controlled to be charged.

According to the above configuration, a battery stack formed by stacking a plurality of rectangular battery cells is bound in the battery cell stacking direction with a binding material that is a flexible loop-shaped string, and each battery is stacked. Since the cell is fixed in a pressurized state, the weight can be reduced while reducing the cost of parts, and the battery cell can be fixed in a pressurized state with a strong pressure.

1 is a schematic perspective view of a battery system according to Embodiment 1 of the present invention. It is a schematic perspective view of the battery system concerning Embodiment 2 of the present invention. FIG. 9 is a schematic perspective view of a battery system according to Embodiment 3 of the present invention. FIG. 10 is a schematic perspective view of a battery system according to Embodiment 4 of the present invention. FIG. 11 is a schematic perspective view of a battery system according to Embodiment 5 of the present invention. FIG. 14 is a schematic perspective view of a battery system according to Embodiment 6 of the present invention. FIG. 2 is an exploded perspective view illustrating a manufacturing process of the battery system illustrated in FIG. 1. FIG. 5 is an exploded perspective view illustrating a manufacturing process of the battery system illustrated in FIG. 4. It is a sectional perspective view showing an example of a binding material. It is a schematic perspective view of the battery system concerning Embodiment 7 of the present invention. FIG. 5 is a horizontal sectional view showing a connection structure between an end plate and a binding material of the battery system shown in FIG. 4. FIG. 5 is a vertical sectional view showing a connection structure between an end plate and a binding material of the battery system shown in FIG. 4. It is a perspective view of a band holder. It is a horizontal sectional view which shows another example of the connection structure of an end plate and a binding material. FIG. 6 is a horizontal sectional view showing a connection structure between an end plate and a binding material of the battery system shown in FIG. 5. FIG. 2 is a block diagram showing an example in which a battery system is mounted on a hybrid car that runs on an engine and a motor. FIG. 3 is a block diagram illustrating an example in which a battery system is mounted on an electric vehicle running only by a motor. FIG. 3 is a block diagram illustrating an example in which a battery system is used for a power storage device.

A battery system according to an embodiment of the present invention includes a battery stack formed by stacking a plurality of rectangular battery cells, and binding the battery stack in the stacking direction of the battery cells, and setting each battery cell to a pressurized state. And a fixed binding material, and the binding material is a flexible loop-shaped string material.

バッテリ The above battery system is characterized in that it can be reduced in weight while reducing the cost of parts, and that the battery cells can be fixed in a pressurized state with strong pressure. That is, the above battery system binds the battery stack with a binding material without using a conventional binding bar using high-tensile steel or a thick metal plate, and furthermore, this binding material is made flexible. This is because the string material is formed into a loop. Unlike a conventional bind bar, a flexible loop-shaped string material does not have a connecting portion to be connected to an end plate, and a tensile force acts on the string material by disposing a battery stack inside a loop. In this state, the battery cell can be fixed in a pressurized state. The flexible and continuous loop-shaped string material having no connecting portion has a feature that the battery cell is fixed in a pressurized state by a strong tensile stress acting in the longitudinal direction without a local decrease in strength due to the connecting portion. is there. Further, the cord material is lighter and has a higher tensile stress than high-tensile steel or a metal plate, and has a feature that the battery cell can be fixed by applying a high pressure to the battery cell.

The present invention is not limited to a battery system and an electric vehicle and a power storage device including the battery system, but may have the following configurations.
In the battery system, the end plates are arranged at both ends in the stacking direction of the battery stack, the end plates are arranged inside the binding material, and the binding material is used to press the battery stack through the end plates. It may be fixed. According to this configuration, both end surfaces of the battery stack are uniformly pressed by the end plate, and the battery cells can be held in a flat shape and pressed.

バッテリ Also, the battery system may have a structure in which protruding portions are provided on outer surfaces of end plates disposed on both ends of the battery stack, and a binding material is disposed on both sides of the protruding portions. According to this configuration, the protruding portion of the end plate is pressed to put the battery laminate in a pressurized state, and the battery laminate having the end plates disposed at both ends inside the loop-shaped binding material is arranged. Thus, the battery stack can be fixed in a pressurized state.

The binding material is preferably a string material having at least a surface as an insulating material. According to this configuration, it is possible to prevent the battery cell from being short-circuited by the binding material and to fix the battery cell in a pressurized state.

The binding material may be a string material of a fiber-reinforced belt formed by embedding high-tensile fibers in a molded material made of a plastic or rubber-like elastic material. According to this configuration, the battery cell can be pressed and fixed with a strong pressure while the binding material is further reduced in weight. This is because the fiber-reinforced belt is reinforced with high-tensile fibers, so that the tensile strength is extremely increased and the weight can be reduced. The ability to increase the tensile strength of the light fiber reinforced belt is significantly reduced by the synergistic effect of the unique structure of binding the battery stack with a seamless continuous loop-like string material, and the battery cell is significantly reduced in weight. Realizes the feature that it can be fixed by pressing with strong pressure.

Furthermore, the binding material may be a string material of a fiber reinforced belt in which a plurality of core wires obtained by twisting high-tensile fibers are buried in the longitudinal direction. According to this configuration, it is possible to provide a fiber reinforced belt in which the tensile strength of the binding material is stronger in the vertical direction than in the horizontal direction.

Furthermore, the fiber reinforced belt is preferably a fiber reinforced belt in which a core wire is embedded in an endless loop shape in the vertical direction. The fiber reinforced belt has a structure in which the high-tensile fibers are stretched in a loop shape and buried in the longitudinal direction, thereby realizing a feature that the binding material is further reduced in weight and the battery cells can be pressed and fixed with strong pressure.

Furthermore, the binding material may be a string material obtained by bundling core wires obtained by twisting a plurality of high-tensile fibers.

Furthermore, in the battery system, the binding material is a string made of a core wire in which high-tensile fibers are twisted, and this string is wound around the battery stack in the direction in which the battery cells are pressed, so that the battery cells are pressed. It may be fixed. According to this configuration, it is possible to press and fix the battery cell with strong pressure while reducing the weight of the binding material.

Furthermore, in the battery system, a binding material may be arranged on the upper and lower surfaces of the battery stack to bind the battery stack. Still further, in the battery system, a binding material may be arranged on both side surfaces of the battery stack to bind the battery stack.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, terms indicating specific directions and positions (for example, “above”, “below”, and other terms including those terms) will be used as necessary. This is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of those terms. In addition, the same reference numeral in a plurality of drawings indicates the same or equivalent part or member.
Further, the embodiments described below show specific examples of the technical concept of the present invention, and do not limit the present invention to the following. In addition, dimensions, materials, shapes, relative arrangements, and the like of the components described below are not intended to limit the scope of the present invention thereto, unless otherwise specified, and are exemplified. Intended. Further, what is described in one embodiment or example can be applied to other embodiments or examples. In addition, the size, positional relationship, and the like of the members illustrated in the drawings are exaggerated in some cases in order to make the description clear.

In the battery system shown in FIGS. 1 to 6, a battery stack 2 in which a plurality of rectangular battery cells 1 are stacked is bound by a binding material 3 of a string material 30. The binding material 3 is an endless cord material 30. The battery stack 2 is disposed inside the loop in an endless manner, and the battery cells 1 are fixed to the pressurized state by the binding material 3. In the

battery systems

100, 200, and 300 shown in FIGS. 1 to 3, the battery stack 2 is disposed inside the endless binding material 3, and the battery cells 1 are fixed in a pressurized state. In the

battery systems

400, 500, and 600 shown in FIGS. 4 to 6, the plate-like end plates 4 are arranged on both end surfaces of the battery stack 2, and both the end plates 4 and the battery stack 2 are formed in a loop-like and endless manner. It is arranged inside the binding material 3. The

battery systems

400, 500, and 600 in which the end plates 4 are arranged on both end surfaces of the battery stack 2 can fix the battery cells 1 in a pressurized state via the end plates 4.

The

battery systems

100 and 400 in FIGS. 1 and 4 dispose the binding material 3 on the upper and lower surfaces of the battery stack 2, and the

battery systems

200 and 500 in FIGS. 3 and 6, the

battery systems

300 and 600 shown in FIGS. 3 and 6 have the binding material 3 disposed on the upper and lower surfaces and both side surfaces of the battery stack 2, and bind the battery stack 2 with the binding material 3. ing. In the above battery system, a plurality of rows, in the figure, two binding materials 3 are arranged in parallel, and the battery stack 2 is fixed in a pressurized state. The battery system that binds the battery stack 2 with the plurality of rows of the binding materials 3 binds the battery cells 1 with the multiple rows of the binding materials 3 so that the end plate 4 and the battery cells 1 are prevented from being deformed while having a strong pressure. There is a feature that can be fixed by pressing. In particular, as shown in FIGS. 1 to 3, the

battery systems

100, 200, and 300 in which the binding material 3 directly binds the battery stack 2 without disposing end plates on both end surfaces of the battery stack 2 By increasing the number of the binding members 3, the battery stack 2 can be bound by the multiple rows of the binding members 3 and the battery cells 1 can be fixed in a pressurized state while preventing deformation of the battery cells 1.

(Battery cell 1)
As shown in FIGS. 1 to 6, the battery cell 1 is a rectangular battery having a width larger than the thickness, in other words, a rectangular battery thinner than the width, and is stacked in the thickness direction to form a battery stack 2. The battery cell 1 is a non-aqueous electrolyte battery having a battery case as a metal case. Battery cell 1, which is a non-aqueous electrolyte battery, is a lithium ion secondary battery. However, the battery cell may be a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The illustrated battery cell 1 is a rectangular battery in which the main surfaces on both sides having a large width are quadrangular, and the battery cells 1 are stacked so that the main surfaces face each other to form a battery stack 2.

(4) The battery cell 1 is a metal battery case having a rectangular outer shape, in which an electrode body (not shown) is housed and filled with an electrolytic solution. The battery case made of a metal case can be manufactured from aluminum or an aluminum alloy. The battery case includes an outer can that is formed by pressing a metal plate into a tubular shape that closes the bottom, and a sealing plate that hermetically closes an opening of the outer can. The sealing plate is a flat metal plate whose outer shape is the shape of the opening of the outer can. This sealing plate is fixed to the outer peripheral edge of the outer can by laser welding, and hermetically closes the opening of the outer can. The positive and negative electrode terminals 13 are fixed to both ends of the sealing plate fixed to the outer can. Further, the battery cell 1 is provided with a gas outlet 12 at the center of the sealing plate or at the bottom of the outer can. The gas discharge port 12 is provided with a discharge valve 11 that opens at a predetermined internal pressure.

複数 The plurality of battery cells 1 stacked on each other are connected in series and / or parallel to each other by connecting the positive and negative electrode terminals 13. In the battery system, the positive and negative electrode terminals 13 of the adjacent battery cells 1 are connected in series and / or parallel to each other via a bus bar (not shown). In the battery system, the output can be increased by increasing the output voltage by connecting the adjacent battery cells 1 in series with each other, and the charging / discharging current can be increased by connecting the adjacent battery cells in parallel.

(Battery laminate 2)
The battery stack 2 has a plurality of battery cells 1 insulated and stacked via a separator (not shown). The separator is formed by molding with an insulating material such as plastic. In the battery cell 1 that is laminated while being insulated by the separator, the outer can can be made of metal such as aluminum. However, the battery stack 2 does not necessarily need to have a separator between the battery cells 1. For example, the battery cell outer can is formed of an insulating material, or the outer periphery of the battery cell outer can is coated with an insulating sheet or an insulating paint or the like, and the adjacent battery cells are insulated from each other, thereby forming a separator. Is unnecessary.

As shown in FIG. 7, the

battery systems

100, 200, and 300 shown in FIGS. 1 to 3 are obtained by pressing a battery stack 2 formed by stacking a plurality of battery cells 1 from both ends with a press (not shown). The battery cell 1 is held in a state of being pressed in the stacking direction, and in this state, the loop-shaped binding material 3 is attached along the outer periphery of the battery stack 2, and the battery stack 2 is arranged inside the binding material 3. I do. FIG. 7 shows a manufacturing process of the battery system 100 shown in FIG. 1, in which the binding material 3 is attached to the battery stack 2 from both sides, and the binding material 3 is arranged on the upper and lower surfaces of the battery stack 2. Is shown. In the battery system 100, after the battery stack 2 is set inside the loop-shaped binding material 3, the pressurized state of the press is released. In this state, in the battery stack 2 set inside the loop-shaped binding material 3, each battery cell 1 is fixed in a pressurized state by the binding material 3.

In the battery system 200 shown in FIG. 2, the battery stack 2 is pressurized from both ends by presses, and the loop-shaped binding material 3 is attached from above and below the battery stack 2, and the battery binding material 3 is attached to the battery stack 2. On both sides. Further, in the battery system 300 shown in FIG. 3, in a state where the battery stack 2 is pressed from both ends by a press, the binding materials 3 are attached from both sides of the battery stack 2, and then the binding materials 3 are attached from above and below. Then, the binding material 3 is disposed on the upper and lower surfaces and both side surfaces of the battery stack 2. However, in the battery system, in a state where the battery stack is pressed from both ends with a press machine, the binding material is attached from above and below the battery stack, and then the binding material is attached from both sides, and the binding material is attached to both sides of the battery stack. It can also be arranged on the surface and the upper and lower surfaces. In the battery system 300 of FIG. 3, the binding materials 3 arranged on both side surfaces of the battery stack 2 and the binding materials 3 arranged on the upper and lower surfaces are stacked so as to intersect at both end surfaces of the battery stack 2. In addition, they are tightly bound.

(End plate 4)
The end plate 4 is inserted inside the binding material 3 and presses the battery stack 2 from both end faces to press the battery cells 1 in the stacking direction. The outer shape of the end plate 4 is substantially equal to or slightly larger than the outer shape of the battery cell 1, and is a square plate shape that is not deformed by disposing the battery stack 2 at a fixed position in a pressurized state. The end plate 4 is inside the binding material 3 and closely adheres to the surface of the battery cell 1 in a surface contact state, and fixes the battery cell 1 in a pressurized state with a uniform pressure.

Further, the end plate 4 shown in FIGS. 4 to 6 is provided with

protrusions

4A and 4B on the outer surface opposite to the surface facing the battery stack 2, and a binding material is provided on both sides of the protrusions 4A and 4B. 3 are arranged. The end plate 4 can mount the loop-shaped binding material 3 on both sides of the

protrusions

4A and 4B while pressing the

protrusions

4A and 4B to make the battery stack 2 pressurized. The end plate 4 shown in FIG. 4 is provided with protrusions 4A extending vertically at the left and right intermediate portions of the outer surface, and the binding material 3 is disposed on both left and right sides of the protrusion 4A. By arranging the binding material 3 along both side edges of the protruding portion 4A, the end plate 4 is positioned at a fixed position while positioning the binding material 3 disposed on both sides of the battery stack 2 and the end plate 4. it can.

エンド In addition, the end plate 4 shown in FIGS. 5 and 6 is provided with a protruding portion 4B having a square shape when viewed from the front, in the center portion of the outer surface except for the outer peripheral portion. As shown in FIG. 5, the end plate 4 is arranged with the loop-shaped binding material 3 positioned on both upper and lower sides of the protruding portion 4B, or as shown in FIG. Can be arranged while positioning the loop-shaped binding material 3. In particular, as shown in FIG. 6, the binding materials 3 arranged along the upper, lower, left, and right edges of the protruding portion 4B are stacked in an intersecting state on the outer surface of the end plate 4 and tightly bound. .

In the

battery systems

400, 500, and 600 shown in FIGS. 4 to 6, as shown in FIG. 8, the end plates 4 are arranged at both ends of the battery stack 2, and the

protrusions

4A and 4B of the end plates 4 at both ends are pressed. The battery cells 1 are held in a state of being pressed in the stacking direction by pressing with a machine (not shown), and in this state, along the upper and lower surfaces of the battery stack 2 and the end plate 4 or along both side surfaces. The looped binding material 3 is mounted, and the battery stack 2 and the end plate 4 are arranged inside the binding material 3. In the

battery systems

400, 500, and 600, the pressurized state of the press is released after the battery stack 2 and the end plate 4 are set inside the loop-shaped binding material 3. In this state, in the battery stack 2 set inside the loop-shaped binding material 3, each battery cell 1 is fixed in a pressurized state by the binding material 3.

(Bundling material 3)
As shown in FIGS. 7 and 8, the binding material 3 is an endless loop-shaped cord material 30. As the binding material 3, a string material 30 whose surface or the whole is an insulating material is suitable. Since the short-circuit current does not flow due to contact with the conductive portion of the battery cell 1, the string 30 made of the insulating material is less restricted in the binding position, and is arranged at an optimal position for the binding, and the battery cell 1 is pressed. There is a feature that can be fixed. However, a conductive string material such as carbon fiber can be used as the binding material. The conductive string material is provided with an insulating layer between the battery stack and the battery stack to insulate the battery cells and bind the battery stack.

As shown in a partially enlarged cross-sectional view of FIG. 9, the binding material 3 of the insulating material is formed by forming a plurality of core wires 33 in which high-tensile fibers are twisted into a molding material 32 such as a rubber-like elastic body or a flexible plastic. It is the cord material 30 of the embedded fiber reinforced belt 31. However, as the binding material of the insulating material, a string made of a wire obtained by twisting high-tensile fibers, or a string obtained by binding a plurality of wires obtained by twisting high-tensile fibers can be used. The fiber-reinforced belt 31 can increase the tensile strength by increasing the core wires 33 of the high-tensile fibers to be buried, and can increase the number of high-tensile fibers to be twisted by increasing the number of high-tensile fibers to be twisted. In the case of a string material in which a plurality of wire materials in which high-tensile fibers are twisted are bundled, the number of wires to be bundled can be increased to further increase the tensile strength.

芳香 As the high-tensile fiber of the cord material 30, an aromatic polyamide fiber registered as a trademark as “aramid fiber” is suitable. Since the aramid fiber (registered trademark) has a tensile breaking strength several times higher than that of a steel rod, a fiber reinforced belt 31 reinforced with an aramid fiber (registered trademark) or a cord made of a wire material in which high-tensile fibers are twisted are used. The tensile strength can be extremely increased while reducing the weight. However, aramid fiber (registered trademark) is suitable for high-tensile fiber, but instead of aramid fiber (registered trademark), polyimide fiber, PBO fiber, ultra-high molecular weight polyethylene fiber, polyarylite fiber, fluorine fiber, PPS fiber And other organic fibers can be used. Further, inorganic fibers such as carbon fiber, silicon carbide fiber, alumina fiber, glass fiber, and metal fiber can be used as the high tension fiber and the aggregate fiber. Since thin inorganic fibers are flexible, they are embedded in a molding material as a twisted core wire to form a fiber reinforced belt, and a wire obtained by twisting fine inorganic fibers is used as a string material, and this wire material is further bundled. Can be used as a cord.

As the molding material 32 of the fiber reinforced belt 31, a rubber-like elastic material such as hydrogenated nitrile rubber (HNBR) used for an engine timing belt is suitable. Excellent plastics can also be used.

As shown in FIG. 9, the fiber reinforced belt 31 is manufactured by insert-molding a plurality of core wires 33 in which high-tensile fibers are twisted into a molding material 32. The plurality of core wires 33 are embedded in the molding material 32 in an endless loop shape and in a posture extending in the longitudinal direction in a posture parallel to each other. In the loop-shaped fiber reinforced belt 31 in which a plurality of endless loop-shaped core wires 33 are embedded in a parallel posture, a plurality of seamless core wires 33 are embedded, and the tensile strength is significantly enhanced. Therefore, like the timing belt of the engine, the fiber reinforced belt 31 in which the plurality of core wires 33 in which the aramid fiber (registered trademark) is twisted in the hydrogenated nitrile rubber (HNBR) is buried in the parallel posture is comparable to the high tensile steel. To achieve a high tensile breaking strength.

The fiber reinforced belt 31 can embed a plurality of core wires 33 in which high-tensile fibers are twisted to increase the tensile strength, but embeds a large number of high-tensile fibers in a parallel posture without twisting the high-tensile fibers and tensions the fibers. Strength can also be increased. This fiber reinforced belt is manufactured by winding one long high tension fiber in a loop shape and embedding the high tension fiber in a parallel posture in a molding material. This fiber reinforced belt can be manufactured by connecting both ends of a high-tensile fiber or burying it in a molding material without connecting. In a fiber reinforced belt in which high-tensile fibers are wound in a loop shape and embedded in a molding material, the tensile force acting on the high-tensile fibers decreases in proportion to the number of times of winding in a loop shape. A fiber reinforced belt wound 1000 times and embedded has a tensile force acting on the high strength fiber reduced to 1/1000 as compared with a belt embedded with one high strength fiber. The fiber reinforced belt realizes a high tensile strength without being displaced by being embedded in a molding material and without necessarily being connected.

The fiber reinforced belt 31 embeds the high-tensile fibers in a posture extending in the longitudinal direction, so that the tensile strength can be particularly increased. However, the fiber-reinforced belt is a state in which the high-tensile fibers of a predetermined length are gathered three-dimensionally without directionality. Can be embedded in the molding material. In addition, the fiber reinforced belt embeds high-tensile fibers buried in the molding material so as to extend in the vertical direction rather than the horizontal direction without burying it in any direction, and has a stronger tensile strength in the vertical direction than in the horizontal direction. can do.

Furthermore, without embedding the high-tensile fiber in the molding material, a tying material consisting of a tying material composed of a wire material obtained by twisting high-tensile fibers, or a tying material consisting of a plurality of tying materials obtained by twisting high-tensile fibers. Since the material realizes excellent tensile breaking strength by the high-tensile fiber, the battery is wound around the surface of the battery stack 2 in the direction in which the battery cell 1 is pressed as shown in FIG. Thus, the battery cell 1 can be fixed in a pressurized state. The string material 30X can be fixed by pressing the battery cell 1 with a strong pressure by increasing the number of times of winding around the battery stack 2. For example, the battery system 700 that winds one string 30X around the battery stack 2 can increase the pressing force of the battery cell 1 in proportion to the number of turns of the string 30X. By increasing the number, the pressing force of the battery cell 1 can be increased without increasing the tensile force acting on one string material 30X. It is necessary to connect the ends of the string material 30X wound around the battery stack 2, but there is a feature that the pressing force of the battery cell 1 can be increased without increasing the connection strength. Both ends of the string material 30X wound around the battery stack 2 can be connected via a connecting member 36 such as a sleeve as shown in FIG. 10, or can be connected with an adhesive.

FIGS. 11 and 12 show a structure in which the binding material 3 is arranged at a fixed position on the end plate 4. FIGS. 11 and 12 are a horizontal sectional view and a vertical sectional view showing a connection structure between the end plate 4 and the binding material 3 of the battery system 400 shown in FIG. In the battery system 400 shown in these figures, two rows of binding materials 3 are mounted on the upper and lower surfaces on both sides of the battery stack 2. Therefore, the pair of end plates 4 have the loop-shaped binding members 3 on both sides of the outer side surface and on both sides of the projection 4A provided at the center. The battery system 400 shown in FIGS. 4, 8, 11, and 12 is configured such that two rows of binding materials 3 arranged on the outer surface of the end plate 4 are connected to the end plate 4 via a band holder 5 and fixing bolts 6. 4 is located at a fixed position.

(Band holder 5)
The band holder 5 is arranged at a fixed position of the end plate 4 while positioning the binding material 3 which is the fiber reinforced belt 31. The band holder 5 shown in FIGS. 4 and 11 is disposed on the outer surface of the end plate 4 on both sides of the protruding portion 4A, and is disposed so as to extend vertically along the outer surface of the end plate 4. The fiber reinforced belt 31 is disposed inside the fiber reinforced belt 31 so that the fiber reinforced belt 31 is disposed at a fixed position on the end plate 4. The band holder 5 shown in FIGS. 8 and 13 is provided with a pair of side walls 52 extending along both sides of the belt-shaped fiber reinforced belt 31 on both sides of the bottom plate 51. A positioning groove 53 for guiding the binding material 3 is provided. In the band holder 5 shown in the figure, the height of the side wall 52 is substantially equal to the thickness of the fiber reinforced belt 31, and the fiber reinforced belt 31 guided by the positioning groove 53 is prevented from coming off the band holder 5. . Further, the band holder 5 is provided with curved surfaces 54 at both ends of the bottom plate 51 forming the bottom surface of the positioning groove 53 in order to suppress the sharp bending of the fiber reinforced belt 31 curved at the corner of the end plate 4. ing. The band holder 5 shown in FIG. 12 has a total length substantially equal to the vertical width of the end plate 4, and is provided at both ends of the bottom plate 51 arranged in the vertical direction so as to bend the fiber reinforced belt 31 with a predetermined radius of curvature. A surface 54 is provided. The band holder 5 can be formed of, for example, a plastic having a strength enough to withstand the pressing by the binding material 3.

As shown in FIG. 8, the band holder 5 is configured to press the end plates 4 stacked on both ends of the battery stack 2 with a press (not shown) so that the battery stack 2 and the end plates 4 are pressed. It is arranged at a fixed position of the end plate 4 while being arranged inside the binding material 3 attached along the outer periphery. Further, the battery system 400 shown in FIGS. 11 and 12 adjusts the pressurized state of the battery stack 2 by the binding material 3 between the band holder 5 and the end plate 4 arranged on the outer surface of the end plate 4. Spacer 7 is inserted. The spacer 7 is a metal plate, and is inserted between the outer surface of the end plate 4 and the band holder 5 to adjust the tension of the binding material 3 that presses the battery stack 2. That is, by adjusting the thickness and the number of the spacers 7 inserted between the end plate 4 and the band holder 5, fine adjustment is performed so that the pressurized state of the battery stack 2 in each battery system becomes uniform. In addition, the pressure difference due to the tolerance of the battery cell 1 and the binding material 3 is eliminated. Such a structure in which the spacer 7 is inserted inside the binding material can easily and easily finely adjust the pressurized state of the battery stack 2.

バンド The band holder 5 arranged at a fixed position of the end plate 4 is fixed to the end plate 4 via fixing bolts 6 penetrating therethrough. Therefore, the band holder 5 and the fiber reinforced belt 31 are provided with through

holes

55 and 35 through which the fixing bolt 6 passes, and the end plate 4 is provided with a screw hole 4 a for screwing the fixing bolt 6. The spacer 7 also has a through hole 7a. Here, although not shown, the fiber reinforced belt 31 having the through-holes 35 can cut a high-tensile fiber embedded in a molding material by embedding a metal tube or a plastic tube having a predetermined inner diameter in the molding material. No through hole can be provided. As described above, the structure in which the binding material 3 and the band holder 5 are directly fixed to the end plate 4 with the fixing bolts 6 penetrating the same is surely and firmly fixed to the fixed position of the end plate 4. There are features that can be done.

Furthermore, the end plate 4 can arrange the binding material 3 at a fixed position by the structure shown in FIG. In the illustrated end plate 4, as described above, the binding material 3, which is the fiber reinforced belt 31, is disposed on the outer surface of the end plate 4 via the band holder 5 and the spacer 7, and the fiber reinforced belt 31 is fixed. It is not directly fixed to the end plate 4 by the bolt 6. The end plate 4 has fixed blocks 41 for preventing the band holder 5 from moving outside the band holders 5 arranged on both sides of the protrusion 4A. The fixing block 41 is fixed to the end plate 4 by screwing a fixing bolt 6 penetrating the fixing block 41 into a screw hole 4b provided in the end plate 4, thereby fixing the band holder 5 in a fixed position. According to this configuration, the fiber reinforced belt 31 fitted into the positioning groove 53 of the band holder 5 does not come off the end plate 4 and has a certain degree of freedom with respect to the longitudinal direction of the string material 30. Placed in a fixed position

Further, the battery system is provided inside the bundling material 3 attached along the outer periphery of the battery stack 2 and the end plate 4, and in particular, at the corners of the battery cells 1 and the end plate 4, for example, the upper and lower end faces. The buffer member may be arranged at a position facing a boundary portion between the lamination surface and a corner portion between the left and right side surfaces and the lamination surface. As shown in the horizontal sectional view of FIG. 15, the battery system 500 shown in FIG. 5 is folded inside the fiber reinforced belt 31 at the corners on both side edges of the end plate 4 so as to have an L-shaped cross section. A bent or curved buffer member 8 is interposed. By arranging the cushioning member 8 at the corner of the end plate 4 in this manner, the radius of curvature of the fiber reinforced belt 31 curved at the corner is increased, and sharp curvature is suppressed to provide the fiber reinforced belt 31. Such a load can be reduced. Although not shown, in the battery system shown in FIGS. 1 to 3, a buffer member may be interposed between the corner of the battery cell 1 and the fiber reinforced belt 31.

1 to 3 are assembled in the following steps.
(1) A predetermined number of battery cells 1 are stacked in the thickness direction of the battery cells 1 with a separator (not shown) interposed therebetween to form a battery stack 2. At this time, the plurality of battery cells 1 stacked on each other are arranged and stacked on the same plane with the sealing plate facing upward.
(2) As shown in FIG. 7, the battery stack 2 is pressed from both ends by a press (not shown) to press the battery stack 2 at a predetermined pressure, and to compress the battery cell 1 and pressurize. Hold in state.
(3) In a state where the battery stack 2 is pressurized, the loop-shaped binding material 3 is attached along the outer peripheral surface of the battery stack 2, and the pressed battery stack 2 is attached to the loop-shaped binding material 3. Place inside.
At this time, a spacer 7 may be arranged between the battery cells 1 arranged at both ends of the battery stack 2 and the binding material 3 to adjust the pressurized state of the battery cells 1.
(4) Further, in this state, the pressing state of the battery stack 2 by the press is released, and the battery stack 2 is bound by the binding material 3 in the stacking direction of the battery cells 1, and each battery cell 1 is connected. It is fixed at a predetermined pressurized state.

4 to 6 are assembled in the following steps.
(1) A predetermined number of battery cells 1 are stacked in the thickness direction of the battery cells 1 with a separator (not shown) interposed therebetween to form a battery stack 2. At this time, the plurality of battery cells 1 stacked on each other are arranged and stacked on the same plane with the sealing plate facing upward.
(2) The end plates 4 are arranged at both ends of the battery stack 2, and the protrusions 4 </ b> A, 4 </ b> B of the pair of end plates 4 are pressed from both sides by a press (not shown). The laminate 2 is pressurized at a predetermined pressure, and the battery cells 1 are compressed and held in a pressurized state.
(3) In a state where the battery stack 2 is pressed by the end plate 4, the loop-shaped binding material 3 is attached along the outer peripheral surfaces of the battery stack 2 and the end plate 4, and the battery stack in a pressed state 2 and the end plate 4 are arranged inside the loop-shaped binding material 3.
At this time, the band holder 5 can be arranged inside the binding material 3 to arrange the binding material at a fixed position on the end plate. In addition, a spacer 7 can be arranged between the outer surface of the end plate 4 and the binding material 3 to adjust the pressurized state of the battery cell 1.
(4) Further, in this state, the pressing state of the end plate 4 by the press is released, and the battery stack 2 and the end plate 4 are bound with the binding material 3 in the stacking direction of the battery cells 1, and each battery is The cell 1 is fixed at a predetermined pressurized state.

The battery system described above is optimal for a vehicle power supply that supplies power to a motor that drives an electric vehicle. Electric vehicles equipped with a battery system include electric vehicles such as hybrid vehicles and plug-in hybrid vehicles that run on both an engine and a motor, or electric vehicles that run on only a motor, and are used as a power source for these electric vehicles. Is done.

(Battery system for hybrid vehicles)
FIG. 16 shows an example in which a battery system is mounted on a hybrid vehicle that runs on both an engine and a motor. The vehicle HV equipped with the battery system shown in this figure includes a vehicle main body 90, an engine 96 for driving the vehicle main body 90 and a driving motor 93, a battery system 100 for supplying power to the motor 93, and a battery system 100. The vehicle includes a generator 94 for charging a battery, and wheels 97 driven by a motor 93 and an engine 96 to drive the vehicle body 90. The battery system 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The vehicle HV runs on both the motor 93 and the engine 96 while charging and discharging the battery of the battery system 100. The motor 93 is driven in a region where the engine efficiency is poor, for example, during acceleration or low-speed running, to run the vehicle. The motor 93 is driven by being supplied with electric power from the battery system 100. The generator 94 is driven by the engine 96 or by regenerative braking when a brake is applied to the vehicle to charge the battery of the battery system 100.

(Electric vehicle battery system)
FIG. 17 shows an example in which a battery system is mounted on an electric vehicle running only by a motor. The vehicle EV equipped with the battery system shown in this figure includes a vehicle body 90, a running motor 93 for running the vehicle body 90, a battery system 100 for supplying electric power to the motor 93, and a battery of the battery system 100. And a wheel 97 driven by a motor 93 to drive the vehicle body 90. The motor 93 is driven by being supplied with electric power from the battery system 100. The generator 94 is driven by energy at the time of regenerative braking the vehicle EV, and charges the battery of the battery system 100.

(Battery system for power storage)
Further, the present invention does not limit the use of the battery system to a battery system mounted on an electric vehicle, and can be used as a battery system for a power storage device that stores natural energy such as solar power and wind power, and It can be used for all applications that store large power, such as a battery system for a power storage device that stores power. For example, as a power supply for homes and factories, a power supply system that charges with sunlight or midnight power and discharges when necessary, a power supply for street lights that charges daytime sunlight and discharges at night, It can also be used as a backup power supply for driving traffic lights. FIG. 18 shows such an example. In the example of use as the power storage device shown in FIG. 18, in order to obtain desired power, a large number of battery systems described above are connected in series or in parallel, and a large-capacity, high-output An example in which the power storage device 80 is constructed will be described.

The power storage device 80 illustrated in FIG. 18 configures a power supply unit 82 by connecting a plurality of battery systems 100 in a unit shape. In each battery system 100, a plurality of battery cells are connected in series and / or in parallel. Each battery system 100 is controlled by a power controller 84. The power storage device 80 drives the load LD after charging the power supply unit 82 with the charging power supply CP. Therefore, power storage device 80 has a charge mode and a discharge mode. The load LD and the charging power supply CP are connected to the power storage device 80 via the discharging switch DS and the charging switch CS, respectively. ON / OFF of the discharge switch DS and the charge switch CS is switched by the power supply controller 84 of the power storage device 80. In the charging mode, the power supply controller 84 turns on the charging switch CS and turns off the discharging switch DS to permit charging of the power storage device 80 from the charging power supply CP. Further, when the charging is completed and the battery is fully charged, or in response to a request from the load LD in a state where a capacity equal to or more than a predetermined value is charged, the power supply controller 84 turns off the charge switch CS and turns on the discharge switch DS to discharge. The mode is switched to the mode, and discharge from the power storage device 80 to the load LD is permitted. If necessary, the charge switch CS is turned on and the discharge switch DS is turned on, so that the power supply of the load LD and the charging of the power storage device 80 can be performed simultaneously.

The load LD driven by the power storage device 80 is connected to the power storage device 80 via the discharge switch DS. In the discharge mode of power storage device 80, power supply controller 84 switches discharge switch DS to ON, connects to load LD, and drives load LD with power from power storage device 80. A switching element such as an FET can be used as the discharge switch DS. ON / OFF of the discharge switch DS is controlled by the power controller 84 of the power storage device 80. Further, the power controller 84 includes a communication interface for communicating with an external device. In the example of FIG. 18, the connection to the host device HT is made according to an existing communication protocol such as UART or RS-232C. If necessary, a user interface for a user to operate the power supply system can be provided.

Each battery system 100 has a signal terminal and a power terminal. The signal terminals include an input / output terminal DI, an abnormal output terminal DA, and a connection terminal DO. The input / output terminal DI is a terminal for inputting / outputting a signal from another battery system 100 or the power controller 84, and the connection terminal DO is a terminal for inputting / outputting a signal to / from the other battery system 100. . The abnormality output terminal DA is a terminal for outputting an abnormality of the battery system 100 to the outside. Further, the power supply terminal is a terminal for connecting the battery systems 100 in series and in parallel. The power supply units 82 are connected to the output line OL via the parallel connection switch 85 and are connected in parallel with each other.

INDUSTRIAL APPLICABILITY A battery system according to the present invention, an electric vehicle including the same, and an electric storage device are preferably used as a battery system for a plug-in hybrid electric vehicle, a hybrid electric vehicle, an electric vehicle, and the like that can switch between an EV traveling mode and an HEV traveling mode. Available. Power storage devices and traffic lights combined with solar cells, such as backup power supplies that can be mounted on computer server racks, backup power supplies for wireless base stations such as mobile phones, home and factory power storage power supplies, and street light power supplies. It can also be used as appropriate for applications such as backup power sources.

100, 200, 300, 400, 500, 600, 700 ... battery system, 1 ... battery cell, 2 ... battery stack, 3 ... binding material, 4 ... end plates, 4A, 4B ... projecting parts, 4a, 4b ... screws Holes, 5: Band holder, 6: Fixing bolt, 7: Spacer, 7a: Through hole, 8: Buffer member, 11: Discharge valve, 12: Gas outlet, 13: Electrode terminal, 30, 30X: String material, 31 ... Fiber reinforced belt, 32 ... Molding material, 33 ... Core wire, 35 ... Through hole, 36 ... Connecting member, 41 ... Fixing block, 51 ... Bottom plate, 52 ... Side plate, 53 ... Positioning groove, 54 ... Curved surface, 55 ... Penetration Hole: 80: power storage device, 82: power supply unit, 84: power supply controller, 85: parallel connection switch, 90: vehicle body, 93: motor, 94: generator, 95: DC / AC inverter, 96: engine, 9 … Wheel, EV… vehicle, HV… vehicle, LD… load, CP… charging power supply, DS… discharge switch, CS… charge switch, OL… output line, HT… host equipment, DI… input / output terminal, DA… abnormal Output terminal, DO ... connection terminal.

Claims

A battery stack formed by stacking a plurality of rectangular battery cells;
A binding material formed by binding the battery stack in the battery cell stacking direction and fixing each of the battery cells in a pressurized state;
A battery system, wherein the binding material is a flexible endless loop-shaped string material.
It comprises a pair of end plates arranged at both ends in the stacking direction of the battery stack,
The battery system according to claim 1, wherein the end plate is disposed inside the binding material, and the binding material fixes the battery stack in a pressurized state via the end plate. .
The battery system according to claim 2, wherein the end plate has a protrusion, and the binding material is disposed on both sides of the protrusion.
(4) The battery system according to any one of (1) to (3), wherein the binding material is a cord material having at least a surface serving as an insulating material.
The battery system according to any one of claims 1 to 4, wherein the binding material is a string material of a fiber-reinforced belt obtained by embedding high-tensile fibers in a molding material made of plastic or a rubber-like elastic body. .
6. The battery system according to claim 5, wherein the binding material is a fiber material of a fiber-reinforced belt in which a plurality of core wires obtained by twisting high-tensile fibers are buried in a longitudinal direction.
7. The battery system according to claim 6, wherein the fiber reinforced belt is a fiber reinforced belt in which a core wire is embedded in an endless loop shape in a vertical direction.
(5) The battery system according to any one of (1) to (4), wherein the binding material is a cord material obtained by bundling core wires obtained by twisting high-tensile fibers.
The binding material is a cord composed of a core wire in which high-tensile fibers are twisted, and the cord is wound around the battery stack in a direction to press the battery cells, and the battery cells are fixed in a pressurized state. The battery system according to any one of claims 1 to 4, wherein:
The battery system according to any one of claims 1 to 9, wherein the binding material is arranged on upper and lower surfaces of the battery stack to bind the battery stack.
The battery system according to any one of claims 1 to 9, wherein the binding material is arranged on both side surfaces of the battery stack to bind the battery stack.
An electric vehicle comprising the battery system according to any one of claims 1 to 11,
The vehicle includes a battery system, a running motor supplied with power from the battery system, a vehicle body including the battery system and the motor, and wheels driven by the motor to run the vehicle body. An electric vehicle comprising a battery system.
A power storage device comprising the battery system according to any one of claims 1 to 11,
The battery system, comprising a power supply controller for controlling the charging and discharging of the battery system,
A power storage device, wherein the power supply controller enables charging of the battery cell with external power and controls charging of the battery cell.