WO2014024431A1

WO2014024431A1 - Battery system, vehicle provided with battery system, and electricity storage device

Info

Publication number: WO2014024431A1
Application number: PCT/JP2013/004656
Authority: WO
Inventors: 一広藤井; 光俊田嶋
Original assignee: 三洋電機株式会社
Priority date: 2012-08-09
Filing date: 2013-08-01
Publication date: 2014-02-13
Also published as: JPWO2014024431A1; JP6184959B2

Abstract

The present invention reliably and stably affixes a pair of end plates at a set position and in a compressed state by means of a binding bar. In this battery system, the pair of end plates (3) are disposed at both ends of a battery stack (2) resulting from stacking a plurality of rectangular batteries (1), and both ends of the binding bar (4) are joined to the corners of the pair of end plates (3). The binding bar (4) results from joining a horizontal section (4X) and a vertical section (4Y) to result in a cross-sectional shape that is an L-shape, and end surface plates (4T) are joined to the ends thereof. In the battery system, the horizontal section (4X) and vertical section (4Y) of the binding bar (4) are positioned at the outer peripheral surface of the end plates (3), the end surface plates (4T) press the outer surfaces of the end plates (3), the battery stack (2) is compressed in the direction of stacking by the pair of end plates (3), and a separation gap (17) at which the binding bar (4) and the end plates (3) are in a non-contacting state is provided between the inner corner (4S) of the horizontal section (4X), vertical section (4Y), and end surface plates (4T) of the binding bar (4) and the outer corner (3S) of the end plates (3).

Description

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

The present invention relates to a battery system in which a plurality of rectangular batteries are stacked to form a battery stack, and both ends of the battery stack are pressed and fixed with end plates, a 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 faces of the battery stack, and the end plates are connected by a bind bar to fix the stacked prismatic batteries in a pressed state. Battery systems have been developed. (See Patent Document 1)

This battery system requires the end plate to fix the square battery in a pressed state with a considerable pressure. If the pressing force of the end plate is weak, the prismatic battery cannot be fixed securely, and the prismatic battery moves due to vibration or the like, causing various harmful effects. Further, in order to prevent the rectangular battery from expanding due to charging / discharging, it is necessary to fix the rectangular battery in a pressurized state with a considerable pressing force. In the battery system of this structure, in order to fix each square battery in a pressed state, end plates are arranged on both end faces of the battery stack in which the square batteries are stacked, and the pair of end plates are pressurized with a press machine. The bind bar is connected to the pair of end plates. The end plates connected by the bind bar are held at a constant interval to fix each rectangular battery in a pressurized state with a predetermined pressure.

JP 2011-60623 A

In the above battery system, the cross-sectional shape of the bind bar can be fixed to the end plate with an L shape, and the vibration resistance of the battery stack can be improved. The L-shaped binding bar improves the bending strength of the bind bar, and the L-shaped bind bar is arranged at the corner of the prismatic battery to prevent the vertical and horizontal misalignment of the prismatic battery. It is. Furthermore, this bind bar can be firmly connected to the end plate as a structure in which the end face plate is connected to both end edges, the end face plate is disposed on the outer side surface of the end plate, and the end plate is locked by the end face plate. . A structure in which the bind bar is connected to the end plate is shown in the perspective view of FIG. The bind bar 204 is connected to the end plate 203 with the horizontal portion 204X and the vertical portion 204Y disposed on the top and side surfaces of the end plate 203 and the end surface plate 204T disposed on the outside of the end plate 203. The bind bar 204 that connects the end face plate 204T at right angles to the edges of the horizontal portion 204X and the vertical portion 204Y is manufactured by pressing a metal plate. Further, the end face plate 204T can be manufactured by welding to the edge of the horizontal portion 204X or the vertical portion 204Y. The bind bar 204 holds the pair of end plates 203 at a predetermined interval by locking the end plate 204T in a state of being in close contact with the outer surface of the end plate 203.

The bind bar shown in FIG. 1 presses a pair of end plates disposed on both end surfaces of the battery stack with a press machine in order to lock and connect the end plate to the outside of the pair of end plates. The end face plate is disposed outside the end plate and connected to the end plate. The bind bar locks the end plate to the outer surface of the end plate, so the press presses the battery stack so that the outer dimension of the pair of end plates is smaller than the inner dimension of the end plate at both ends of the bind bar. To do. The battery stack is compressed to make the outer dimension of the end plate smaller than the inner dimension of the end plate at both ends of the bind bar, so that the end plate can be smoothly arranged on the outer surface of the end plate. That is, the pair of pressed end plates can be smoothly inserted inside the end face plates at both ends of the bind bar. When the press state of the end plate is released in this state, the end face plate does not come into close contact with the outer surface of the end plate, and the inner corner of the end face plate, the vertical portion, and the horizontal portion is the corner portion of the end plate. A very large force acts on the contact portion. In this state, the reaction when the end plate presses and presses the battery stack acts locally only on the inner corner of the bind bar. For this reason, an extremely large force acts on an extremely small area at the inner corner of the bind bar. The powerful force acting on the inner corner of the bind bar can cause deformation or damage to the corner where the bind bar contacts the end plate, and the distortion caused by the deformation is not constant in all battery systems. The state of deformation distortion causes the distance between the pair of end plates to fluctuate. For this reason, in a state where the press state is released and the end plate is fixed at a constant interval by the bind bar, the end plate cannot be held at a constant interval, and the compressed state of the battery stack becomes non-uniform. In this state, the pressing force of the stacked rectangular batteries is not constant, and the compression state of the battery stack further varies due to swelling of the charged and discharged rectangular batteries.

Furthermore, the battery system described above is not limited to the state in which the press state is released, and when the square battery expands with time due to charge / discharge, the end plate is pressed with a strong force due to the reaction by the battery stack. Even in this state, if the bind bar and the end plate are locally in contact with each other at the corners, a strong force concentrates on the corners of the bind bar and the end plate. In FIG. 1, when a force acts on the end plate 203 in the direction indicated by the arrow due to the reaction of the battery stack 202 to be pressed, the end face plate 204T is pushed in the direction indicated by the arrow. In this state, when the corners of the bind bar 204 and the end plate 203 are in contact with each other, the stress at the corner indicated by point A in the drawing is the strongest. In this figure, the bent portion that connects the horizontal portion 204X and the end face plate 204T at a right angle becomes easier to deform as it moves away from the point A to the point B, and connects the vertical portion 204Y and the end face plate 204T at a right angle. The bent portion is easily deformed as it moves away from the point A to the point C. However, the corner portion of the end face plate 204T is connected to both the horizontal portion 204X and the vertical portion 204Y of the bind bar 204 and hardly deforms. When the end plate 203 is pushed in the direction indicated by the arrow, it is difficult to deform. The pressure is concentrated and the stress is maximized, causing damage to the corners of the bind bar 204.

Bind bars that have cracks due to breakage at the corners become larger and the end plates cannot be placed in place by separating the end plate from the horizontal or vertical part. If the end plate cannot be placed in a fixed position and the prismatic battery cannot be fixed in a pressurized state with a considerable pressure, the battery stack cannot be fixed in a pressurized state with a certain pressure, and the prismatic battery moves relative to the vibration. Thus, various harmful effects are generated in the rectangular battery. For example, distortion is applied to the connection part between the metal plate bus bar connecting the square batteries in series or in parallel to the electrode terminals of the square battery, and the connecting part between the electrode terminals of the square battery and the battery case. In addition, it gives obstacles.

The present invention was developed for the purpose of solving the above drawbacks. An important object of the present invention is to arrange a pair of end plates in a fixed position with a bind bar while maintaining a very simple structure, and to stably and stably press the end plate with a bind bar over a long period of time. A battery system that can be fixed to a vehicle, a vehicle including the battery system, and a power storage device.

Means for Solving the Problems and Effects of the Invention

The battery system of the present invention includes a battery stack 2 formed by stacking a plurality of prismatic batteries 1, a pair of end plates 3, 3 'disposed at both ends in the stacking direction of the battery stack 2, and both ends. Are connected to the corners of the pair of

end plates

3 and 3 ′, and a bind bar 4 is formed by fixing a plurality of prismatic batteries 1 in a pressurizing state in the stacking direction. The bind bar 4 has a horizontal section 4X and a vertical section 4Y connected to each other at a right angle so that the cross-sectional shape is an L-shape. The end face plate 4T which covers is connected. In the battery system, the horizontal portion 4X and the vertical portion 4Y of the bind bar 4 are located on the outer peripheral surface of the

end plates

3 and 3 ′, and the end surface plate 4T presses the outer surface of the

end plates

3 and 3 ′, The battery stack 2 is pressed in the stacking direction by the

plates

3 and 3 ′, the inner corner 4S of the horizontal portion 4X, the vertical portion 4Y and the end face plate 4T of the bind bar 4, and the outer corner of the

end plates

3 and 3 ′. A separation gap 17 is provided between the part 3S and the bind bar 4 and the

end plates

3 and 3 ′ in a non-contact state.

The above battery system has a very simple structure, and a pair of end plates are placed in a fixed position with a bind bar, and the end plate is securely and stably fixed in place with a bind bar over a long period of time. There are features that can be done. This is because the above battery system separates the bind bar and the end plate between the horizontal and vertical portions of the bind bar and the inner corners of the end plate and the outer corners of the end plate in a non-contact state. This is because a gap is provided. In this battery system, the end plate of the bind bar is placed in surface contact with the outer surface of the end plate. Therefore, after connecting the bind bar, the end plate is released from the press state, or repeatedly charged and discharged over time. Even if the square battery expands and the end plate is pressed with a strong force, a strong force does not act locally only on the corners of the bind bar and the end plate. In this assembly system, even if the end state of the end plate to which the bind bar is connected is released in the assembly process, a strong force is not forcibly applied to the corners of the bind bar and the end plate. Contact with the end plate over a wide area. The bind bar keeps the battery stack in a constant compressed state with the pair of end plates always having a constant interval. In addition, even if the prismatic battery expands with time, the pair of end plates are held at a constant interval to prevent adverse effects due to the expansion of each prismatic battery.

The battery system of the present invention can be provided with the separation gap 17 that chamfers the outer corner 3S of the end plate 3 ′ and makes the corner between the bind bar 4 and the end plate 3 ′ non-contact.
In the battery system described above, the corners of the bind bar and the end plate can be brought into a non-contact state very easily, and a large force can be prevented from acting locally.

In the battery system of the present invention, through holes 18 are provided in the corners of the horizontal part 4X, the vertical part 4Y and the end face plate 4T of the bind bar 4, and the corners of the bind bar 4 and the end plate 3 are brought into a non-contact state. A separation gap 17 can be provided.
In the above battery system, the corners of the binding bar and the end plate can be made in a non-contact state, and a large force can be prevented from acting locally, and the metal plate is bent and welded. Bind bars can be mass-produced easily, easily and inexpensively.

In the battery system of the present invention, the outer corner portion 3S of the end plate 3 ′ is chamfered, and the through hole 18 is provided in the corner portion of the horizontal portion 4X, the vertical portion 4Y, and the end surface plate 4T of the bind bar 4 to bind. A separation gap 17 can be provided in which the corner between the bar 4 and the end plate 3 ′ is in a non-contact state.
In the above battery system, the corners of the bind bar and end plate can be kept in a non-contact state to prevent a large force from acting locally, and the metal plate is bent and welded. Bind bars can be mass-produced easily, easily and inexpensively.

In the battery system of the present invention, the area in which the bind bar 4 and the

end plates

3 and 3 ′ are not in contact with each other in the separation gap 17 can be 1 mm ² or more.
The above battery system increases the non-contact area, so that the binding bar and the end plate are reliably prevented from contacting only at the corners, and the distance between the pair of end plates is constant with the binding bar. Can be retained.

In the battery system of the present invention, the outer shape of the

end plates

3 and 3 ′ is a quadrangle, and four bind bars 4 can be connected to the corners of the quadrangle.
In the battery system described above, the end plate can be reliably fixed at a constant interval with four bind bars.

In the battery system of the present invention, the rectangular battery 1 can be a non-aqueous electrolyte battery having a battery case 10 as a metal case.
In the above battery system, since the rectangular battery is a non-aqueous electrolyte battery with a metal case, the battery stack can be fixed in a pressurized state with an end plate, and each rectangular battery can be held in a pressurized state at a constant pressure. Moreover, the capacity | capacitance which can be charged / discharged with respect to a volume can be enlarged.

An electric vehicle according to the present invention includes any one of the battery systems 100 described above, a motor 93 for traveling that is supplied with power from the battery system 100, a vehicle main body 90 including the battery system 100 and the motor 93, and a motor. And a wheel 97 that is driven by the vehicle 93 and causes the vehicle main body 90 to travel.
The above-described electric vehicle can effectively prevent the vibration caused by traveling and the negative effects caused by the square battery that is repeatedly charged and discharged and expands with time, while the battery system including the plurality of square batteries is mounted on the vehicle. This is because the pair of end plates can be arranged at fixed positions by the bind bar, and the end plates can be reliably and stably fixed to the pressurized state by the bind bar.

The power storage device of the present invention includes any one of the battery systems 100 described above and a power controller 84 that controls charging / discharging of the battery system 100. The power supply controller 84 can charge the prismatic battery 1 with external power and can control the prismatic battery 1 to be charged.
While the above power storage device uses a battery system that stores a large amount of power with a plurality of rectangular batteries, it can prevent adverse effects caused by the rectangular batteries that are repeatedly charged and discharged and expand over time.

It is a principal part expansion perspective view of the conventional battery system. It is a perspective view of the battery system concerning one embodiment of the present invention. FIG. 3 is a vertical longitudinal sectional view of the battery system shown in FIG. 2. FIG. 3 is an exploded perspective view of the battery system shown in FIG. 2. It is a disassembled perspective view which shows the laminated structure of a square battery and a spacer. It is a disassembled perspective view of the battery laminated body formed by laminating | stacking the spacer of another structure and a square battery. It is a principal part expansion perspective view of the bind bar of the battery system shown in FIG. It is an expanded view of the bind bar shown in FIG. It is a disassembled perspective view of the battery system concerning other embodiment of this invention. FIG. 10 is an enlarged perspective view of an end plate and a bind bar of the battery system shown in FIG. 9. It is an expanded sectional view which shows the connection structure of the end plate and bind bar shown in FIG. It is a bottom perspective view which shows another example which provides a through-hole in a bind bar. It is a block diagram which shows the example which mounts a battery system in the hybrid car which drive | works with an engine and a motor. It is a block diagram which shows the example which mounts a battery system in the electric vehicle which drive | works only with a motor. It is a block diagram which shows the example which uses a battery system for an electrical storage apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery system and a vehicle including the battery system and a power storage device for embodying the technical idea of the present invention, and the present invention includes the battery system and the battery system. The vehicle and the power storage device are not specified as follows. Furthermore, this specification does not limit the members shown in the claims to the members of the embodiments.

A battery system 100 shown in FIGS. 2 to 5 includes a battery stack 2 in which a plurality of rectangular batteries 1 are stacked, and a pair of end plates 3 disposed at both ends in the stacking direction of the battery stack 2. , Both ends are connected to the corners of the pair of end plates 3, and a bind bar 4 is provided that fixes the plurality of prismatic batteries 1 in a stacked state in the stacking direction.

As shown in FIG. 5, the rectangular battery 1 is a rectangular battery having a width wider 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 prismatic battery 1 is a non-aqueous electrolyte battery having a battery case 10 as a metal case. The rectangular battery 1 which is a non-aqueous electrolyte battery is a lithium ion secondary battery. However, the square battery may be a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The rectangular battery 1 shown in the figure is a battery in which both wide surfaces are quadrangular and are laminated so that both surfaces face each other to form a battery stack 2.

The prismatic battery 1 has an electrode body (not shown) housed in a metal battery case 10 having a rectangular outer shape and is filled with an electrolytic solution. The battery case 10 made of a metal case can be made of aluminum or an aluminum alloy. The battery case 10 includes an outer can 10A in which a metal plate is pressed into a cylindrical shape that closes the bottom, and a sealing plate 10B that airtightly closes an opening of the outer can 10A. The sealing plate 10B is a flat metal plate, and its outer shape is the shape of the opening of the outer can 10A. The sealing plate 10B is laser-welded and fixed to the outer peripheral edge of the outer can 10A to airtightly close the opening of the outer can 10A. The sealing plate 10 B fixed to the outer can 10 A has positive and negative electrode terminals 13 fixed to both ends thereof, and a gas discharge port 12 is provided between the positive and negative electrode terminals 13. A discharge valve 11 that opens at a predetermined internal pressure is provided inside the gas discharge port 12. The battery stack 2 shown in FIG. 5 is formed by stacking a plurality of rectangular batteries 1 in such a manner that the surfaces on which the discharge valves 11 are provided are positioned substantially on the same surface, and the discharge valves 11 of the respective square batteries 1 are arranged on the first surface. 2A. In the illustrated battery stack 2, a plurality of rectangular batteries 1 are stacked in a posture in which the sealing plate 10 B provided with the discharge valve 11 is an upper surface.

The discharge valve 11 is opened when the internal pressure of the rectangular battery 1 becomes higher than the set pressure, thereby preventing the internal pressure from increasing. The discharge valve 11 has a built-in valve body (not shown) that closes the gas discharge port 12. The valve body is a thin film that is destroyed at a set pressure, or a valve that is pressed against the valve seat by an elastic body so as to open at the set pressure. When the discharge valve 11 is opened, the inside of the prismatic battery 1 is opened to the outside through the gas discharge port 12, and the internal gas is released to prevent the internal pressure from increasing.

A plurality of rectangular batteries 1 stacked on each other are connected in series and / or in parallel with each other by connecting positive and negative electrode terminals 13. In the battery system, positive and negative electrode terminals 13 of adjacent rectangular batteries 1 are connected in series and / or in parallel with each other through a bus bar 14. A battery system in which adjacent rectangular batteries are connected in series with each other can increase the output voltage by increasing the output voltage, and can connect adjacent rectangular batteries in parallel to increase the charge / discharge current.

In the battery stack 2 shown in FIG. 3 and FIG. 4, 14 prismatic batteries 1 are stacked on each other via a spacer 7, and these prismatic batteries 1 are connected in series. In the illustrated battery stack 2, adjacent rectangular batteries 1 are arranged in opposite directions, and adjacent electrode terminals 13 on both sides thereof are connected by a bus bar 14 to connect two adjacent rectangular batteries 1 in series. All the prismatic batteries 1 are connected in series. However, the present invention does not specify the number of prismatic batteries constituting the battery stack and the connection state thereof.

As shown in FIGS. 3 and 5, the battery stack 2 has a spacer 7 sandwiched between the stacked rectangular batteries 1. The spacer 7 insulates the adjacent rectangular batteries 1. The spacer 7 shown in the figure is an insulating plate formed of plastic in a plate shape. In particular, a spacer formed of a plastic having a low thermal conductivity has an effect of effectively preventing thermal runaway of adjacent rectangular batteries. The spacer 7 can be stacked so that the adjacent rectangular batteries 1 are not displaced as a shape in which the rectangular batteries 1 are fitted and arranged at a fixed position.

As described above, the rectangular battery 1 that is insulated and stacked by the spacer 7 can have an outer can made of metal such as aluminum. However, it is not always necessary for the battery stack to interpose a spacer between the rectangular batteries. For example, spacers can be formed by insulating rectangular batteries that are adjacent to each other by, for example, forming a rectangular battery outer can with an insulating material, or covering the outer periphery of the rectangular battery outer can with an insulating sheet or insulating paint. It is because it can be made unnecessary. Furthermore, the battery stack without interposing a spacer between the square batteries is a method of directly cooling using a refrigerant or the like without adopting an air-cooling method in which cooling air is forced between the square batteries to cool the square batteries. Can be used to cool the prismatic battery.

Further, the spacer 7 shown in FIGS. 3 and 5 is provided with a cooling gap 16 that allows a cooling gas such as air to pass through a portion sandwiched between the prismatic battery 1 in order to effectively cool the prismatic battery 1. Is provided. The spacer 7 in FIGS. 3 and 5 is provided with grooves 15 extending to both side edges on the surface facing the prismatic battery 1, and a cooling gap 16 is provided between the spacer 7 and the prismatic battery 1. In the illustrated spacer 7, a plurality of grooves 15 are provided in parallel with each other at a predetermined interval. In the illustrated spacer 7, grooves 15 are provided on both surfaces, and a cooling gap 16 is provided between the prismatic battery 1 and the spacer 7 adjacent to each other. This structure has an advantage that the square battery 1 on both sides can be effectively cooled by the cooling gaps 16 formed on both sides of the spacer 7. However, the spacer can be provided with a groove only on one side, and a cooling gap can be provided between the prismatic battery and the spacer. The cooling gap 16 in the figure is provided in the horizontal direction so as to open to the left and right of the battery stack 2. The air forcibly blown into the cooling gap 16 directly and efficiently cools the outer can 10 A of the rectangular battery 1. This structure has a feature that the prismatic battery 1 can be efficiently cooled while effectively preventing thermal runaway of the prismatic battery 1.

The spacer 7 described above can cool the prismatic battery 1 by providing a cooling gap 16 between the spacer 7 and forcibly blowing a cooling gas such as cooling air into the cooling gap 16. However, the spacer does not necessarily need to be provided with a cooling gap between the prismatic battery. As shown in FIG. 6, the spacer 37 is exposed to the surface of the battery stack 32, and the exposed portion 37 A is the cooling plate 20. It can also be set as the structure connected to a thermal coupling state. In this battery system, the cooling plate 20 can be cooled, the spacer 37 can be cooled by the cooling plate 20, and the prismatic battery 1 can be cooled by the spacer 37. The cooling plate 20 can be cooled by providing heat radiation fins (not shown) on the surface, or can be forcibly cooled by circulating a cooling refrigerant or coolant inside. Furthermore, although not shown, the surface of the prismatic battery can be insulated without providing a spacer between the prismatic batteries.

The end plate 3 is connected to the bind bar 4 to pressurize the battery stack 2 from both end surfaces and press the square battery 1 in the stacking direction. The end plate 3 is fixed to the bind bar 4 to fix each rectangular battery 1 of the battery stack 2 in a pressurized state with a predetermined tightening pressure. The outer shape of the end plate 3 is substantially equal to or slightly larger than the outer shape of the prismatic battery 1, and a rectangular shape that is not deformed by connecting the bind bars 4 to the four corners and fixing the battery stack 2 in a pressurized state. It is a plate shape. This end plate 3 has bind bars 4 connected to the four corners, and is in close contact with the surface of the prismatic battery 1 in a surface contact state, and fixes the prismatic battery 1 in a pressurized state with uniform pressure. In the battery system, end plates 3 are arranged at both ends of the battery stack 2, and the end plates 3 at both ends are pressed by a press (not shown), and the prismatic battery 1 is held in a state of pressing in the stacking direction. In this state, the bind bar 4 is fixed to the end plate 3, and the battery stack 2 is held and fixed at a predetermined tightening pressure. After the end plate 3 is connected to the bind bar 4, the pressurization state of the press machine is released.

The bind bar 4 is a metal plate that connects the horizontal portion 4X and the vertical portion 4Y at a right angle and has an L-shaped cross section. Further, the bind bar 4 in FIG. 4 has end face plates 4T connected to both ends. The end face plate 4T is connected to the end edges of the vertical portion 4Y and the horizontal portion 4X. The end surface plate 4T is connected to the vertical portion 4Y and the horizontal portion 4X at a right angle so as to contact the outer surface of the end plate 3 in a surface contact state. The bind bar 4 having this shape can be manufactured by pressing a metal plate. However, the bind bar 4A shown in FIGS. 7 and 8 is provided with a protrusion 4Z outside the horizontal portion 4X. An end face plate 4T is formed. The protrusion 4Z shown in the drawing is composed of an end face plate 4T connected to the outer edge of the horizontal part 4X, and a laminated part 4R connected to one side of the end face plate 4T on the vertical part 4Y side. The bind bar 4A is formed by bending the end surface plate 4T of the projecting portion 4Z at a right angle with respect to the horizontal portion 4X, and further bending the stacked portion 4R at a right angle with respect to the end surface plate 4T. 4R is fixed by welding to the vertical portion 4Y. Thereby, the bind bar 4A forms an end face plate 4T in a vertical posture at the end edge. The laminated portion 4R to be welded is welded along the boundary with the vertical portion 4Y, or overlapped with the vertical portion 4Y and connected by a method such as spot welding. The bind bar 4A shown in the figure is provided with a protruding portion 4Z on the horizontal portion 4X, bending the protruding portion 4Z, and fixing the laminated portion 4R to the vertical portion 4Y to form an end face plate 4T in a vertical posture. The bind bar may be provided with a protruding portion in the vertical portion, and the protruding portion is bent to provide an end face plate, and the laminated portion is welded and fixed to the horizontal portion. Furthermore, the bind bar is provided with protrusions on both the horizontal part and the vertical part, and the protrusions are bent, and the bent protrusions are stacked and welded to provide an end face plate. You can also.

The bind bar 4 is connected to the end plate 3 in a state where the end plate 4T is disposed on the outer surface of the end plate 3 and is locked to the end plate 3. The bind bar 4 connects the end face plate 4T to the end plate 3 in a locked state, and fixes the battery stack 2 in a pressurized state with the end plate 3. Further, the bind bar 4 in FIG. 4 is fixed by fixing a set screw 24 to the outer peripheral surface of the end plate 3. The illustrated end plate 3 is provided with a female screw hole 3b at a position where a set screw 24 is screwed. Further, the bind bar 4 shown in the figure opens the through holes 4b through which the set screws 24 are inserted at both ends of the vertical portion 4Y, and the through holes 4a through which the fixing screws 23 to be described later are inserted at both ends of the horizontal portion 4X. Is open.

In the battery system 100 described above, both ends of the bind bar 4 are fixed to the pair of end plates 3, the battery stack 2 is sandwiched between the pair of end plates 3, and each rectangular battery 1 is stacked in a stacking direction with a predetermined tightening pressure. Press to fix. The clamping pressure of the prismatic battery 1 is a pressing force per unit area that acts on both surfaces of the prismatic battery 1. The clamping pressure is calculated by [the pressing force with which the end plate 3 presses the battery stack 2 in the stacking direction] / [the area of the flat portion of the rectangular battery 1]. This clamping pressure is preferably set to 10 MPa or more and 1 MPa or less. If the tightening pressure is too weak, the expansion of the prismatic battery 1 cannot be effectively suppressed. On the other hand, if it is too strong, the battery case 10 of the prismatic battery 1 is damaged. In particular, in the prismatic battery 1 using the battery case 10 as a metal case, the deformation amount of the battery case 10 in the stacking direction of the prismatic battery 1 is extremely small and substantially does not change. The square battery 1 cannot be reliably held in a pressurized state, and if the tightening pressure is too strong, the battery case 10 of the square battery 1 is damaged. For this reason, it is extremely important to press and fix the respective square batteries 1 in the stacking direction while keeping the tightening pressure within a predetermined range. Accordingly, the tightening pressure is set to an optimum value within the above-mentioned range in consideration of the type and size of the rectangular battery 1 and the material, shape, thickness, size, and physical properties of the electrode body of the battery case 10.

The bind bar 4 and the end plate 3 are provided with separation gaps 17 that are not in contact with each other, that is, in a non-contact state. The separation gap 17 is provided between the inner corners of the horizontal portion 4X, the vertical portion 4Y and the end face plate 4T of the bind bar 4 and the outer corner of the end plate 3. The separation gap 17 is provided so that the corners of the bind bar 4 and the end plate 3 are not in contact with each other so that the reaction when the battery stack 2 is compressed does not concentrate on the corners. It is. The separation gap 17 can effectively prevent a strong stress from acting on the corner by increasing the area to be in a non-contact state. However, if the area of the non-contact state by the separation gap 17 is too large, the area where the end face plate 4T contacts the end plate 3 becomes small. Therefore, the area that is in a non-contact state in the separation gap 17 is, for example, 1 mm ² or more and smaller than 25 mm ² , preferably 2 mm ² or more, 10 mm ² or less, more preferably 3 mm ² or more, 10 mm ² or less.

Furthermore, in the battery system shown in FIGS. 9 to 11, the outer corner of the end plate 3 'is chamfered, and the corner between the bind bar 4B and the end plate 3' is in a non-contact state. In this battery system, as shown by hatching in the enlarged perspective view of FIG. 10, the outer corner 3S of the end plate 3 'is chamfered to provide a separation gap 17, and the corner between the bind bar 4 and the end plate 3' is formed. Is in a non-contact state. The end plate 3 'has the outer corner 3S chamfered in a flat shape to provide a separation gap 17, but the end plate chamfers the outer corner in a curved surface projecting from the center portion and has a separation gap. Can also be provided. This end plate is chamfered into a shape in which a part of the curved surface does not contact the inner corner of the bind bar to provide a separation gap.

As shown in the developed view of FIG. 8, the bind bar 4 A in which the protruding portion 4 Z is provided in the horizontal portion 4 X and the vertical portion 4 Y, and the protruding portion 4 Z is bent at a right angle to provide the end face plate 4 A. After cutting so as to cut 19, bending and welding are performed, and through holes 18 can be provided at the corners of the binding bar 4 A to provide separation gaps 17. In addition, as shown in FIG. 12, the bind bar in which the separation gap 17 is provided by post-processing is provided with end face plates 4T at both ends of a bind bar 4C having a L-shaped cross section by press-molding a metal plate into a predetermined shape. After providing, the through-hole 18 can be provided with the drill in the corner part of the horizontal part 4X, the vertical part 4Y, and the end surface plate 4T, and the isolation | separation clearance gap 17 can be provided. The through-hole 18 can be provided by opening the through-hole 18 with a drill so as to penetrate from the inner surface side of the inner corner portion 4S to the outer side. In this method, the separation gap 17 can be easily provided in the bind bar 4C that presses the metal plate and connects the horizontal portion 4X, the vertical portion 4Y, and the end face plate 4T in an integrated structure.

The battery system of the present invention chamfers the outer corner 3S of the end plate 3 'and provides through holes 18 at the corners of the horizontal portion 4X, the vertical portion 4Y, and the end surface plate 4T of the bind bar 4 to bind the bind bar. It is also possible to provide the separation gap 17 with the corners of 4 and the end plate 3 ′ in a non-contact state.

Further, in the battery system 100 shown in FIGS. 2 and 4, the surface plate 8 is disposed on the upper surface of the battery stack 2, and the end surface on the sealing plate 10B side of the rectangular batteries 1 stacked on each other by the surface plate 8. (Upper surface in the figure) is covered. The surface plate 8 is formed in an outer shape along the upper surface of the battery stack 2. The surface plate 8 is formed of an insulating plastic such as nylon resin or epoxy resin. Further, as shown in FIGS. 2 and 4, the surface plate 8 is provided with an opening window 29 for exposing the electrode terminal 13 of the rectangular battery 1 and connecting it to the bus bar 3. The illustrated surface plate 8 is provided with a plurality of opening windows 29 along both side portions of the battery stack 2. The opening window 29 is sized and shaped along the outer shape of the bus bar 14 so that it can be connected to the electrode terminal 13 while guiding the bus bar 14 to a fixed position. The bus bar 14 disposed in the opening window 29 of the surface plate 8 is fixed to the electrode terminal 13 of the prismatic battery 1 and connects the plurality of prismatic batteries 1 to a predetermined connection state. However, it is not always necessary for the battery pack to dispose a surface plate on the upper surface of the battery stack.

3 is provided with a base plate 9 on which the battery stack 2 is placed. The base plate 9 fixes the end plate 3. In order to fix the end plate 3 to the base plate 9, through holes 3 a extending in the vertical direction in the figure and extending in a direction parallel to the rectangular battery 1 are provided on both sides. A fixing screw 23 is inserted into the through hole 3 a, and the fixing screw 23 fixes the tip end portion to the base plate 9 and fixes the end plate 3 to the base plate 9. The fixing screw 23 is screwed into a female screw hole 9a provided in the base plate 9, and is fixed to the base plate 9, or is screwed into a nut provided on the bottom surface of the base plate to be fixed to the base plate.

As shown in FIG. 10, a battery system 100 that is mounted on a vehicle and supplies electric power to a motor 93 that runs the vehicle can use the base plate 9 as a chassis 92 of the vehicle. The battery system 100 is placed on a vehicle chassis 92, a fixing screw 23 is inserted into a through hole 3 a provided in the end plate 3, and the fixing screw 23 is inserted into a female screw hole (not shown) provided in the chassis 92. It is screwed and fixed to the chassis 92 of the vehicle. The battery system 100 described above uses the base plate 9 as the vehicle chassis 92, but the base plate is not necessarily specified as the vehicle chassis. For example, as shown in FIG. 11, the base plate 9 can be made of a metal plate, and the battery system 100 can be fixed on the base plate 9. The battery system 100 can be mounted on a vehicle with the base plate 9 fixed on a vehicle chassis 92.

The above battery system is assembled in the following steps.
(1) A battery stack 2 is formed by stacking a predetermined number of prismatic batteries 1 in the thickness direction of the prismatic battery 1 with a spacer 6 interposed therebetween. At this time, the plurality of prismatic batteries 1 stacked on each other are stacked such that the positive and negative electrode terminals 13 at both ends of the sealing plate 10B are alternately reversed.
(2) The end plates 3 are arranged at both ends of the battery stack 2, and the pair of end plates 3 are pressed from both sides with a press machine (not shown), and the end plates 3 are used to hold the battery stack 2 in a predetermined manner. Pressurize with pressure to compress the square battery 1 and hold it in a pressurized state.
(3) The surface plate 8 is disposed at a fixed position on the upper surface of the battery stack 2 in a state where the battery stack 2 is pressed by the end plate 3.
(4) Further, the bind bar 4 is connected and fixed to the pair of end plates 3 in a state where the battery stack 2 is pressed by the end plates 3. At this time, in the bind bar 4, the horizontal portion 4 X and the vertical portion 4 Y are disposed on the outer peripheral surface of the end plate 3, and the end surface plate 4 T is disposed on the outer surface of the end plate 3.
Further, in this state, the press state of the end plate 3 by the press machine is released, and the end surface plate 4T is brought into close contact with the outer surface of the end plate 3 in a surface contact state. Thereafter, a set screw 24 penetrating the vertical portion 4Y is fixed to the outer peripheral surface of the end plate 3 by screwing.
In this state, the battery stack 2 is held at a predetermined clamping pressure via a pair of end plates 3 held at a predetermined interval by the bind bar 4.
(5) On both sides of the battery stack 2, the opposing electrode terminals 13 of the adjacent rectangular batteries 1 are connected by a bus bar 14. The bus bar 14 is disposed in the opening window 29 of the surface plate 8 and connects the electrode terminals 13 exposed from the opening window 29 to each other. The bus bar 14 connects the square batteries 1 in series or in series and parallel. The bus bar 14 is screwed to the electrode terminal 13 or welded to the electrode terminal 13.
(6) The battery stack 2 is disposed and fixed on the upper surface of the base plate 9. The battery stack 2 is fixed to the base plate 9 via a fixing screw 23 that passes through the horizontal portion 4X of the bind bar 4 and the through hole 3a of the end plate 3.

The above battery system is optimal for a power supply device that supplies electric power to a motor that drives an electric vehicle. However, the present invention does not specify the use of the battery system as a power supply device mounted on an electric vehicle, and can be used, for example, as a power supply device that stores natural energy such as solar power generation or wind power generation, and stores midnight power. Like power supply devices such as power supply devices, it is optimal for all applications that store large amounts of power.

As an electric vehicle equipped with a battery system, an electric vehicle such as a hybrid vehicle or a plug-in hybrid vehicle that runs with both an engine and a motor, or an electric vehicle that runs only with a motor can be used, and used as a power source for these electric vehicles. Is done.

(Battery system for hybrid vehicles)
FIG. 13 shows an example in which a battery system is mounted on a hybrid vehicle that runs with both an engine and a motor. A vehicle HV equipped with the battery system shown in this figure has an engine 96 and a running motor 93 that run the vehicle HV, a battery system 100 that supplies power to the motor 93, and power generation that charges a square battery of the battery system 100. A vehicle body 90 on which the machine 94, the engine 96, the motor 93, the battery system 100, and the generator 94 are mounted, and wheels 97 that are driven by the engine 96 or the motor 93 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 travels by both the motor 93 and the engine 96 while charging and discharging the square battery of the battery system 100. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the battery system 100. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked, and charges the prismatic battery of the battery system 100.

(Battery system for electric vehicles)
FIG. 14 shows an example in which a battery system is mounted on an electric vehicle that runs only with a motor. A vehicle EV equipped with the battery system shown in this figure includes a traveling motor 93 that travels the vehicle EV, a battery system 100 that supplies electric power to the motor 93, and a generator that charges a rectangular battery of the battery system 100. 94, a vehicle main body 90 on which the motor 93, the battery system 100, and the generator 94 are mounted, and a wheel 97 that is driven by the motor 93 and causes the vehicle main body 90 to travel. The battery system 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The motor 93 is driven by power supplied from the battery system 100. The generator 94 is driven by energy when regeneratively braking the vehicle EV, and charges the square battery of the battery system 100.

(Battery system for power storage device)
Furthermore, this battery system can be used not only as a power source for a mobile body but also as a stationary power storage facility. For example, as a power source for home and factory use, a power supply system that is charged with sunlight or midnight power and discharged when necessary, or a streetlight power supply that charges sunlight during the day and discharges at night, or during a power outage It can also be used as a backup power source for driving signals. Such an example is shown in FIG. The battery system 100 shown in this figure forms a battery unit 82 by connecting a plurality of battery blocks 81 in a unit form. Each battery block 81 has a plurality of prismatic batteries 1 connected in series and / or in parallel. Each battery block 81 is controlled by a power supply controller 84. The battery system 100 drives the load LD after charging the battery unit 82 with the charging power source CP. For this reason, the battery system 100 includes a charge mode and a discharge mode. The load LD and the charging power source CP are connected to the battery system 100 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 battery system 100. In the charging mode, the power controller 84 switches the charging switch CS to ON and the discharging switch DS to OFF to permit charging of the battery system 100 from the charging power source 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 of a predetermined value or more is charged, the power controller 84 turns off the charging switch CS and turns on the discharging switch DS to discharge. The mode is switched and discharging from the battery system 100 to the load LD is permitted. Further, if necessary, the charge switch CS can be turned on and the discharge switch DS can be turned on to supply power to the load LD and charge the battery system 100 simultaneously.

The load LD driven by the battery system 100 is connected to the battery system 100 via the discharge switch DS. In the discharge mode of the battery system 100, the power supply controller 84 switches the discharge switch DS to ON, connects to the load LD, and drives the load LD with the power from the battery system 100. As the discharge switch DS, a switching element such as an FET can be used. ON / OFF of the discharge switch DS is controlled by the power supply controller 84 of the battery system 100. The power controller 84 also includes a communication interface for communicating with external devices. In the example of FIG. 15, the host device HT is connected in accordance with an existing communication protocol such as UART or RS-232c. Further, if necessary, a user interface for the user to operate the power supply system can be provided.

Each battery block 81 includes a signal terminal and a power supply 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 the other battery block 81 or the power supply controller 84, and the connection terminal DO is a terminal for inputting / outputting a signal to / from the other battery block 81. . The abnormality output terminal DA is a terminal for outputting abnormality of the battery block 81 to the outside. Furthermore, the power supply terminal is a terminal for connecting the battery blocks 81 in series and in parallel. The battery units 82 are connected to the output line OL via the parallel connection switch 85 and are connected in parallel to each other.

The battery system of the present invention is optimally used for a power supply device that supplies power to a motor of a vehicle that requires a large amount of power, or a power storage device that stores natural energy or midnight power.

DESCRIPTION OF SYMBOLS 100 ... Battery system 1 ... Square battery 2 ... Battery laminated body 2A ... 1st surface 3 ... End plate 3 '... End plate 3S ... Outer corner 3a ... Through-hole 3b ... Female screw hole 4 ... Bind bar 4A ... Bind bar 4B Bind bar 4C Bind bar

4X Horizontal portion

4Y Vertical portion

4Z Projection portion 4T End face plate 4R Laminated portion 4S Inner corner 4a Through hole 4b Through hole 7 Spacer 8 Surface plate 9 Base plate 9a ... Female screw hole 10 ... Battery case 10A ... Exterior can 10B ... Sealing plate 11 ... Discharge valve 12 ... Gas exhaust port 13 ... Electrode terminal 14 ... Bus bar 15 ... Cold Groove 16 ... Cooling gap 17 ... Separation gap 18 ... Through hole 19 ... Area 20 ... Cooling plate 23 ... Fixing screw 24 ... Set screw 29 ... Opening window 32 ... Battery stack 37 ... Spacer 37A ... Exposed part 81 ... Battery block 82 ... Battery unit 84 ... Power controller 85 ... Parallel connection switch 90 ... Vehicle main body 92 ... Chassis 93 ... Motor 94 ... Generator 95 ... DC / AC inverter 96 ... Engine 97 ... Wheel 202 ... Battery stack 203 ... End plate 204 ... Bind bar 204X ... Horizontal portion 204Y ... Vertical portion 204T ... End plate EV ... Vehicle HV ... Vehicle LD ... Load CP ... Power supply for charging 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 laminate formed by laminating a plurality of prismatic batteries;
A pair of end plates arranged at both ends in the stacking direction of the battery stack;
A battery system comprising a bind bar formed by connecting both end portions to corners of a pair of end plates and fixing a plurality of prismatic batteries in a pressurized state in a stacking direction,
The binding bar has a horizontal section and a vertical section connected at right angles to form an L-shaped cross section, and the horizontal section and the vertical section connect an end face plate that covers the outer surface of the end plate to the edge. And
The horizontal and vertical portions of the bind bar are positioned on the outer peripheral surface of the end plate, the end plate presses the outer surface of the end plate, and the battery stack is pressed in the stacking direction with a pair of end plates. ,
A separation gap is provided between the horizontal and vertical portions of the bind bar and the inner corners of the end plate and the outer corner of the end plate so that the bind bar and the end plate are not in contact with each other. A battery system characterized by
The battery system according to claim 1, wherein an outer corner portion of the end plate is chamfered to provide a separation gap in which the corner portion between the bind bar and the end plate is in a non-contact state.
The through-hole is provided in the corner part of the horizontal part of the said bind bar, a perpendicular | vertical part, and an end surface plate, and the separation clearance which makes the corner part of a bind bar and an end plate a non-contact state is provided. Battery system.
The outer corner portion of the end plate is chamfered, and through holes are provided in the corner portions of the horizontal portion, the vertical portion, and the end plate of the bind bar so that the corner portions of the bind bar and the end plate are not in contact with each other. The battery system according to claim 1, wherein a separation gap is provided.
5. The battery system according to claim 1, wherein an area in which the bind bar and the end plate are not in contact with each other in the separation gap is 1 mm 2 or more.
The battery system according to any one of claims 1 to 5, wherein the outer shape of the end plate is a quadrangle, and four bind bars are connected to corners of the quadrangle.
The battery system according to any one of claims 1 to 6, wherein the rectangular battery is a non-aqueous electrolyte battery using a battery case as a metal case.
An electric vehicle comprising the battery system according to any one of claims 1 to 7,
The battery system, a travel motor powered by the battery system, a vehicle body on which the battery system and the motor are mounted, and wheels that are driven by the motor and cause the vehicle body to travel. An electric vehicle provided with the battery system characterized by the above.
A power storage device comprising the battery system according to any one of claims 1 to 7,
A power controller for controlling charging and discharging of the battery system;
A power storage device, wherein the power supply controller controls the prismatic battery to be charged while external battery power is allowed to be charged.