JP2021022545A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect an adjacent battery cell and enhance safety even if a high temperature gas is discharged from any of the battery cells. SOLUTION: A power supply device 100 has a plurality of battery cells 1 and a plurality of battery cells 1 each having an outer can and having one end surface as an electrode and having a discharge valve 2 for discharging gas when an internal pressure rises. , The battery block 40A that holds the outer can in a parallel posture so that one end face is flush with each other, and the end faces of the battery block 40A are arranged on the end faces of a plurality of battery cells 1, and the discharge valve 2 is The heat absorbing sheet 68, which is at least partially broken by the heat and pressure of the gas released when the valve is opened to allow the gas to permeate, and the end face of the battery block 40A are arranged apart from the heat absorbing sheet 68. It includes a separating plate 64 that is released when the discharge valve 2 is opened, breaks the heat absorbing sheet 68, and receives the permeated gas. [Selection diagram] FIG. 12

Description

The present invention relates to a power supply device.

A power supply device such as a battery pack is used as a power source for assisted bicycles, electric motorcycles, electric tools, electric cleaners, and the like. In the power supply device, a large number of battery cells are arranged and connected in series or in parallel to increase the output and capacity. Each battery cell is provided with a safety valve on one end face of a cylindrical outer can, for example, on the positive electrode side, in order to release high-pressure and high-temperature gas inside the cell due to some abnormality to the outside of the cell. There is. The safety valve detects when the outer can becomes high pressure and opens the valve, and discharges the high-pressure and high-temperature gas inside the outer can to the outside of the cell.

In the unlikely event that a high-temperature gas is discharged from one of the battery cells, it is necessary to avoid a situation in which this gas heats the other normal battery cell and the abnormality spreads. In particular, when the end faces provided with the safety valves of a plurality of battery cells held in a parallel position by the battery block are arranged so as to be adjacent to each other, the high temperature gas released from one battery cell is used as another battery. It is possible that the safety valve of the cell will be adversely affected. For example, as shown in the exploded perspective view of FIG. 14, in the configuration in which the isolation plate 864 is arranged on the end face of the power supply device 800 so that the high temperature and high pressure gas is not directly blown to other parts, FIG. As shown in the enlarged perspective view of the above, it is conceivable that the high-temperature gas is repelled by the isolation plate 864, and as a result, the safety valve of the adjacent battery cell is heated.

Japanese Unexamined Patent Publication No. 2008-251472 Japanese Unexamined Patent Publication No. 2008-251470

One of an object of the present invention is to provide a power supply device that protects adjacent battery cells and enhances safety even if high-temperature gas is discharged from any of the battery cells.

The power supply device according to the first aspect of the present invention includes a plurality of battery cells each having an outer can, one end surface as an electrode, and a discharge valve for discharging gas when the internal pressure rises, and the plurality of batteries. A battery block that holds the outer cans in a parallel posture so that one end face thereof is flush with each other, and the end faces of the battery blocks are arranged on the end faces of the plurality of battery cells. An endothermic sheet that allows at least a part of the gas to break due to the heat and pressure of the gas released when the discharge valve is opened to allow the gas to permeate, and an endothermic sheet of the battery block that is separated from the endothermic sheet. It is provided with a separating plate which is released when the discharge valve is opened, breaks the endothermic sheet, and receives the permeated gas.

With the above configuration, even if one battery cell should release high-temperature, high-pressure gas from the discharge valve, the released gas will be isolated by the endothermic sheet in a state where the force and heat of the gas are weakened. It will be sprayed on the board. Therefore, the released gas is weakened by the endothermic sheet and further diffused by the isolation plate to reduce the temperature and pressure. Therefore, it is possible to protect the adjacent battery cell from the released gas.

It is a vertical sectional view which shows the power-source device which concerns on one Embodiment of this invention. It is a perspective view which shows the battery assembly of the power supply device of FIG. It is an exploded perspective view of the battery assembly of FIG. It is a further exploded perspective view of the battery assembly of FIG. It is a side view of one battery block of FIG. FIG. 5 is a vertical cross-sectional view taken along the line VI-VI of the battery block of FIG. FIG. 5 is a vertical cross-sectional view taken along the line VII-VII of the battery block of FIG. FIG. 6 is an enlarged cross-sectional view of a main part of FIG. It is a perspective view which shows the state which attached the isolation plate to one battery block of FIG. It is a perspective view which shows the state which the isolation plate was removed from FIG. It is a vertical sectional view of the battery block of FIG. FIG. 11 is an enlarged schematic cross-sectional view of a main part of the battery block of FIG. It is an exploded perspective view which shows the appearance which the exhaust space is formed between the battery blocks. It is an exploded perspective view which shows the other battery block. FIG. 6 is an enlarged perspective view showing a traveling direction when gas is discharged from one battery cell of the power supply device of FIG. 14.

In addition to the above-described configuration, the power supply device of a certain aspect of the present invention may be configured as follows. The endothermic sheet is at least partially broken by the gas released when the discharge valve is opened to allow the gas to permeate and proceed toward the isolation plate, and the gas is released to the isolation plate. It is possible to prevent the diffused and reflected gas from reaching the end face of the adjacent battery cell in the unbroken region. With the above configuration, it is possible to effectively protect the situation where the gas is reflected by the isolation plate and adversely affects the adjacent battery cells by blocking the end face of the adjacent battery cells with the unbroken region of the endothermic sheet. ..

Further, the endothermic sheet absorbs the heat of the gas by breaking at least a part of the gas released when the discharge valve is opened, and the heat of the gas is reflected by the isolation plate. It is possible to prevent the situation where the radiant heat generated by the radiant heat reaches the end face of the adjacent battery cell in the unbroken region. With the above configuration, the heat of the gas can be absorbed by the endothermic sheet, and the end face of the adjacent battery cell can be protected by the unbroken region.

Further, the power supply device may further include a lead plate on the end face of the battery block to which the electrodes of the plurality of battery cells are connected. The endothermic sheet has an insulating property and can be brought into close contact with the lead plate. With the above configuration, the endothermic sheet can be brought into close contact with the surface of the lead plate, and the high-temperature and high-pressure gas released from the safety valve of the battery cell can be effectively weakened while breaking the endothermic sheet.

One side of the endothermic sheet is an adhesive surface. With the above configuration, the endothermic sheet can be easily attached to the lead plate.

A plurality of the battery blocks are connected, and the isolation plate may be interposed between the surfaces connecting the battery blocks to each other.

The outer can of the battery cell may have a cylindrical shape.

The endothermic sheet can be made of a silicone resin.

The isolation plate can be made of mica, glass epoxy or aluminum.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below exemplify a configuration for embodying the technical idea of the present invention, and the present invention is not specified as the following. Moreover, the member shown in the claims is never specified as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention to the specific ones unless otherwise specified. It is just an example of explanation. The size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. Further, in the following description, members of the same or the same quality are shown with the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are composed of the same member and the plurality of elements are combined with one member, or conversely, the function of one member is performed by the plurality of members. It can also be shared and realized. In addition, the contents described in some examples and embodiments can be used in other embodiments and embodiments.

An example in which the power supply device shown below is mainly applied to a power source for driving an electric vehicle such as an electric scooter, an electric cart, or an electric vehicle that runs only by a motor will be described. Even if the power supply device of the present invention is used in a hybrid vehicle that runs on both an engine and a motor, or in an application other than an electric vehicle that requires a large output, for example, a power storage device for a home or a factory. Good.
[Embodiment 1]

The power supply device according to the first embodiment is shown in FIGS. 1 to 8. In these figures, FIG. 1 is a vertical sectional view showing a power supply device 100 according to an embodiment of the present invention, FIG. 2 is a perspective view showing a battery assembly 40 of the power supply device 100 of FIG. 1, and FIG. 3 is FIG. An exploded perspective view of the battery assembly 40, FIG. 4 is a further exploded perspective view of the battery assembly 40 of FIG. 3, FIG. 5 is a side view of the battery block 40A of FIG. 3, and FIG. 6 is a VI of the battery block 40A of FIG. A vertical sectional view taken along the line VII, FIG. 7 shows a vertical sectional view taken along the line VII-VII of the battery block 40A of FIG. 5, and FIG. 8 shows an enlarged sectional view of a main part of FIG. In the power supply device 100 shown in these figures, the battery assembly 40 is built in the outer case 9. As shown in FIGS. 2, 3, 4, 4 and the like, the battery assembly 40 is covered with an insulating plate 4 on one surface thereof. The battery assembly 40 includes a pair of battery blocks 40A and 40B, and the pair of battery blocks 40A and 40B are arranged and connected at opposite positions (left and right in FIG. 1). Further, an isolation plate 64 is arranged between the battery blocks 40A and 40B as shown in FIG. Further, as shown in the exploded perspective view of FIG. 4, a heat absorbing sheet 68 is arranged between the isolation plate 64 and the battery blocks 40A and 40B. In addition, a circuit board 8 on which a charge / discharge circuit for controlling charge / discharge of the battery cell 1 and a protection circuit are mounted is arranged on the upper surface of the battery assembly 40.
(Battery blocks 40A, 40B)

In each of the battery blocks 40A and 40B, as shown in FIGS. 1 to 7, a plurality of battery cells 1 are arranged in a parallel posture, both ends are arranged in the same plane, and the lead plate 45 is connected to the end electrodes 13 at both ends. doing. In the battery assembly 40, a pair of battery blocks 40A and 40B arranged at opposite positions are arranged side by side in the axial direction of the battery cell 1, and an insulating space 6 is provided as a space between the pair of battery blocks 40A and 40B. .. As shown in FIG. 5 and the like, the lead plate 45 is a current collecting terminal made of a metal plate or the like. As shown in the enlarged cross-sectional view of FIG. 8, each of the battery blocks 40A and 40B has an end electrode 13 arranged at a position facing the insulating space 6.
(Battery cell 1)

As shown in the enlarged cross-sectional view of FIG. 8, the battery cell 1 is provided with a discharge port of a discharge valve 2 that opens at a set pressure on the end face. The battery cell 1 is provided with end electrodes 13 at both ends. In this battery cell 1, the opening of a metal outer can made of aluminum or the like is hermetically sealed with a sealing plate, a convex electrode is provided on the sealing plate to form a first end electrode 13A, and the bottom surface of the outer can is second. The end electrode 13B is used. The discharge port of the discharge valve 2 is provided on the convex electrode side or on the bottom surface of the outer can.

The battery cell 1 is a lithium ion battery of a cylindrical battery. Lithium-ion batteries have a large capacity relative to size and weight, and the total capacity of the power supply device can be increased. However, the power supply device of the present invention does not specify the battery cell as a lithium ion battery. Other rechargeable secondary batteries can be used in the battery cell. Further, in the power supply device 100 of FIG. 1, the battery cell 1 is a cylindrical battery, but a square battery can also be used as the battery cell. In each battery cell 1, a lead plate 45 is welded to the end electrodes 13 at both ends thereof, and adjacent battery cells 1 are connected in series or in parallel.
(Battery holder 44)

The battery blocks 40A and 40B include a battery holder 44 that holds a plurality of battery cells 1 so that one end face is flush with each other in a posture in which the outer cans are parallel to each other. As shown in FIGS. 4 and 7, the battery cell 1 is arranged at a fixed position by the battery holder 44. The battery holder 44 is manufactured by molding an insulating material such as plastic. In the battery holder 44 shown in the figure, all the battery cells 1 are arranged in a fixed position in a parallel posture. Since the battery cell 1 arranged at a fixed position in the battery holder 44 has lead plates 45 welded to both ends thereof, each battery cell is arranged so that the lead plates 45 welded to the respective ends are located on the same surface. 1 is arranged in the battery holder 44 so that both ends thereof are located on substantially the same surface.

The battery holder 44 is provided with an insertion portion 44A into which the battery cell 1 is inserted and arranged at a fixed position. In the power supply device 100 shown in FIGS. 4, 6, and 7, since the battery cell 1 is a cylindrical battery, the insertion portion 44A is cylindrical. The battery holder 44 is formed by molding plastic into a tubular shape and is provided with an insertion portion 44A inside. The insertion portion 44A is provided with openings 44B at both ends that expose the end portions of the battery. The opening 44B exposes the end of the battery cell 1 inserted into the insertion portion 44A from the insertion portion 44A to the outside. The end face of the battery cell 1 exposed to the opening 44B becomes an end electrode 13, and a lead plate 45 is welded and fixed thereto.
(Insulation space 6)

As shown in FIG. 1, the battery assembly 40 in which the insulating space 6 is provided between the pair of battery blocks 40A and 40B and the end faces of the battery cells 1 are arranged on both sides of the insulating space 6 is the discharge port of the discharge valve 2. Is arranged in the direction of the insulating space 6. When the discharge valve 2 is opened, the high-temperature ejected gas discharged from the discharge port is injected toward the end faces of the opposing battery blocks 40A and 40B. The high-temperature ejected gas injected onto the facing surfaces of the battery cells 1 at the facing positions causes thermal runaway of the battery cells 1. In the power supply device 100 of FIGS. 4 and 6, the isolation plate 64 is arranged in the middle of the insulating space 6.
(Isolation plate 64)

The isolation plate 64 is a heat-resistant insulating sheet having a heat-resistant temperature, that is, a melting point, which is not melted by the ejected gas discharged from the discharge valve 2. As the insulating sheet, for example, flame-retardant heat-resistant paper can be used. However, instead of the heat-resistant paper, the separating plate 64 can be made of paper or non-woven fabric in which inorganic fibers that are not melted by ejected gas are assembled in a sheet shape, or an inorganic sheet in which an inorganic material is bonded in a thin sheet shape. Since these isolation plates 64 can be made thin, the isolation plate 64 can widen the insulation space 6 and smoothly discharge the ejected gas without reducing the substantial volume of the insulation space 6. In the insulating isolation plate 64, the end faces and lead plates 45 of the battery cells 1 arranged on both sides can be arranged in an insulated state. However, the material constituting the isolation plate does not necessarily have to be an insulating material. For example, an insulating sheet can be laminated on the surface of the isolation plate to insulate the surface. However, the structure in which the insulating material is laminated on the surface of the separating plate as the insulating material can further improve the insulating property of the separating plate.

The isolation plate 64 is arranged in a posture parallel to the end surface of the battery cell 1. In the power supply device 100 of FIG. 6, the isolation plate 64 is arranged in the middle of the insulation space 6, and the insulation space 6 for the ejected gas is provided on both sides of the isolation plate 64. The isolation plate 64 prevents the heat generated (fluttering heat) from the battery blocks 40A and 40B facing the isolation plate 64 from being conducted to the battery blocks 40B and 40A located on the back surface side of the isolation plate 64.
(Gas discharge direction regulation wall 65)

The gas discharge direction regulation wall 65 defines a gas flow path when gas is discharged from the battery cell 1. By regulating the flow of gas with the gas discharge direction regulation wall 65, it is possible to guide the gas in an arbitrary direction and safely discharge the gas from the power supply device 100 to the outside.

FIG. 9 is a perspective view showing a state in which the isolation plate 64 is attached to one of the battery blocks 40A in FIG. As shown in this figure, the isolation plate 64 has a gas discharge direction regulating wall defining a gas discharge path 66 that guides the gas released when the discharge valve 2 is opened in a predetermined direction on at least one surface thereof. Forming 65. With this configuration, even if any of the battery cells 1 should have an internal pressure rise and discharge gas, the gas discharge direction is regulated by the gas discharge direction regulation wall 65 provided on the isolation plate 64. be able to. As a result, it is possible to improve the safety of the power supply device by designing so that the high temperature and high pressure gas is not sprayed on the undesired part.

By providing the gas discharge direction regulation wall 65 on the isolation plate 64 as shown in FIGS. 3 and 9, the gas discharge direction can be regulated along the gas discharge direction regulation wall 65. As a result, the high-temperature and high-pressure gas can be prevented from flowing in the direction of the heat-sensitive member by the gas discharge direction regulation wall 65, and can be guided so as to be safely discharged to the outside of the power supply device. As a result, even if any of the battery cells 1 included in the battery blocks 40A and 40B facing each other is arranged in a posture in which the discharge valves 2 face each other through the insulating space 6, the gas flow at the time of outgassing can be prevented. It can be regulated and safely discharged to the outside of the power supply.

Further, the insulating space 6 is not provided with a barrier such as a closing member such as a frame portion surrounding the insulating space 6. Therefore, the high-temperature and high-pressure gas discharged from the battery cell 1 and introduced into the insulating space 6 is once introduced into the insulating space 6 and then guided by the gas discharge direction regulation wall 65 to smoothly outside the insulating space 6. Is discharged to. As a result, it is possible to avoid a situation in which the high-temperature and high-pressure gas stops between the battery blocks 40A and 40B, and a situation in which the high-temperature and high-pressure gas heats the battery cells other than the battery cell in which the thermal runaway has occurred.

The gas discharge direction regulation wall 65 is provided on the isolation plate 64 in a region where one end faces of the battery cells 1 are adjacent to each other. As a result, even if gas is discharged from the battery cell, the gas discharge direction is interposed between the end faces so that the gas heats the valve provided with the discharge valve 2 of the adjacent battery cell. It can be prevented by the regulation wall 65 and the safety can be enhanced. Further, by forming the gas discharge direction regulating wall 65 in a convex shape, it can be easily formed integrally with the isolation plate 64, and the strength against the pressure of the gas can be exhibited.

The gas discharge direction regulating wall 65 is preferably formed on both sides of the isolation plate 64. As a result, the gas discharge direction regulation wall 65 of the isolation plate 64 interposed between the battery blocks 40A and 40B regulates the gas discharge direction of the battery cells arranged on both sides of the isolation plate 64. Is possible, and safety is further enhanced. However, the gas discharge direction regulation wall 65 may be formed on only one side of the isolation plate 64. For example, if the battery cell can be arranged so that only the negative electrode side faces one side of the battery block, the gas discharge direction regulation wall may be omitted. Further, two isolation plates having a gas discharge direction regulating wall provided on only one surface may be combined and laminated so that the surface provided with the gas discharge direction regulating wall faces the battery block.

The gas discharge direction regulation wall 65 is preferably formed integrally with the isolation plate 64. Further, the gas discharge direction regulation wall 65 composed of the isolation plate 64 and a separate member may be adhered to the isolation plate 64. Such a gas discharge direction regulation wall 65 can be made of PBT containing glass fiber. Alternatively, the isolation plate 64 may be made of mica, glass epoxy or aluminum having excellent heat resistance. The gas discharge direction regulation wall 65 may be formed of a separate member from the isolation plate 64. In this case, the gas discharge direction regulation wall 65 may be made of the same material as the isolation plate 64, or may be a heat-resistant cushion material, rubber material, or the like.

The gas discharge direction regulation wall 65 shown in FIGS. 7 and 9 is formed in a linear shape formed in the vertical direction. Details of such a gas discharge direction regulation wall 65 are shown in the side view of FIG. The gas discharge direction regulation wall 65 is preferably arranged between the electrodes on the side where the discharge valve 2 of the battery cell 1 is provided. As a result, it is possible to avoid a situation in which the gas discharged from the discharge valve 2 is injected into the discharge valve 2 of another adjacent battery cell, causing the battery cell to undergo thermal runaway. As described above, since the discharge valve 2 is generally provided on the electrode on the positive electrode side, it is preferable to provide the gas discharge direction regulating wall 65 between the positive electrodes of the battery cell 1 as a result. Further, in the power supply device shown in FIG. 5 and the like, gas is guided in the vertical direction in the figure by the gas discharge direction regulation wall 65. Therefore, a structure capable of safely discharging gas to the outside, such as an exhaust duct, is provided in the vertical direction of the power supply device as needed.
(Endothermic sheet 68)

Further, the power supply device 100 arranges the endothermic sheets 68 on the end faces of the plurality of battery cells 1 to improve safety in the event that gas is discharged from the battery cells. A perspective view showing a state in which the isolation plate 64 is removed from the battery block 40A of FIG. 9 is shown in FIG. As shown in this figure, endothermic sheets 68 are arranged on the end faces of the plurality of battery cells 1 at the end faces of the battery blocks 40A and 40B. At least a part of the endothermic sheet 68 is broken by the heat and pressure of the gas released when the discharge valve 2 is opened, and this gas is allowed to permeate. On the other hand, the isolation plate 64 is arranged at the end faces of the battery blocks 40A and 40B apart from the endothermic sheet 68, as shown in the enlarged cross-sectional view of the main part of FIG. The isolation plate 64 is released when the discharge valve 2 is opened, breaks the endothermic sheet 68, and receives the permeated gas. With such a configuration, even if one battery cell 1 should release high temperature and high pressure gas from the discharge valve 2, the endothermic sheet 68 is used to weaken the gas force and heat, and the isolation plate is used. By spraying on the 64, the endothermic sheet 68 and the weakened gas are further diffused by the isolation plate 64 to lower the temperature and pressure, and it is possible to protect the adjacent battery cell 1.

In a battery block in which a plurality of battery cells are connected, conventionally, the gap between batteries has been potted with a potting resin. By integrally adhering the potting resin to the surface of a plurality of battery cells, the thermal energy of the battery cells is conducted to the potting resin, and the heat capacity is secured by the potting resin to protect the battery cells. In such a configuration, as shown in the exploded perspective view of the power supply device 900 of FIG. 13, in a structure in which a plurality of battery blocks 940A and 940B are connected, a frame portion 962 is formed around the exhaust space 963 to form an exhaust space. It prevents the potting resin from flowing into the 963. In addition, the situation where the potting resin flows in from the discharge port of the discharge valve of the battery cell and hinders the discharge of gas is avoided.

Further, in the configuration in which the isolation plate 864 is arranged on the end face of the battery block 840A as in the power supply device 800 shown in the exploded perspective view of FIG. 14, the battery block 840 and the isolation plate are arranged as shown in the enlarged cross-sectional view of FIG. By providing an exhaust space 863 between the battery cell and the battery cell, the influence of gas and high temperature is prevented. However, if the size of the exhaust space 863 cannot be sufficiently secured in this configuration, the high-temperature and high-pressure gas and flame ejected from the battery cell are repelled by the isolation plate 864 and stay in the exhaust space 863, resulting in high heat. There was a problem that the influence of was not sufficiently reduced.

On the other hand, in the power supply device 100 according to the present embodiment, by arranging the isolation plate 64 away from the end face of the battery block 40A, the heat of the battery block 40A at high temperature is suppressed and the heat is absorbed as described above. By providing the sheet 68 on the lead plate 45, it is possible to protect the end face of the battery cell around the battery cell that has released gas. Further, since the heat capacity can be secured by the endothermic sheet 68, the potting resin which has been conventionally required can be omitted, and the weight can be reduced, the manufacturing process can be simplified, and the cost can be reduced.

The endothermic sheet 68 has an insulating property and is in close contact with the lead plate 45. As a result, the endothermic sheet 68 is provided on the surface of the lead plate 45, and the high-temperature and high-pressure gas released from the safety valve of the battery cell 1 can be effectively weakened while breaking the endothermic sheet 68. Therefore, it is preferable that one surface of the endothermic sheet 68 has an adhesive surface. As a result, the endothermic sheet 68 can be easily attached to the lead plate 45.

FIG. 12 shows a traveling direction of the gas released from the battery block 40A and an enlarged schematic cross-sectional view of a main part of the endothermic sheet 68. As shown in this figure, at least a part of the endothermic sheet 68 is broken by the gas released when the discharge valve 2 is opened. This gas passes through the endothermic sheet and travels toward the isolation plate 64. Further, after the gas hits the isolation plate 64 and is diffused and reflected, the situation where the gas reaches the end face of the adjacent battery cell is prevented in the unbroken region of the endothermic sheet 68. That is, although the endothermic sheet 68 is partially broken by the high-pressure and high-temperature gas injected from the battery cell 1, the pressure and heat of the gas are partially lost when the endothermic sheet 68 is broken. Further, the injected gas is partially reduced in heat and pressure when it collides with the isolation plate 64 and is reflected, and is diffused by the isolation plate 64 at the time of collision. As a result, when the gas is repelled by the isolation plate 64 and reaches the endothermic sheet 68 again, the temperature and pressure of the gas are considerably weakened as compared with the initial momentum. Then, the injected gas is diffused by the isolation plate to change the traveling direction thereof, and heads toward the end face of the battery cell adjacent to the periphery of the battery cell 1 that has released the gas. However, these adjacent battery cells are covered with an unbroken region of the endothermic sheet 68. Since the gas whose temperature and pressure have been reduced as described above does not have enough force to break the endothermic sheet 68 again, the end faces of these battery cells are protected by the endothermic sheet 68. As a result, it is possible to effectively protect the battery cells located around the battery cells that have released the gas in the unbroken region of the endothermic sheet 68. In this way, the endothermic sheet 68 can prevent a situation in which burning due to the generation of high-temperature and high-pressure gas is suppressed, and the gas is reflected by the isolation plate 64 and adversely affects a wide range of adjacent battery cells. ..

The endothermic sheet 68 absorbs the heat of this gas and lowers the temperature by breaking at least a part of the gas released when the discharge valve 2 is opened. In addition, it is possible to prevent the radiant heat generated by reflecting the heat of the deprived gas by the isolation plate 64 from reaching the end face of the adjacent battery cell in the unbroken region. In this way, the endothermic sheet 68 can exert a heat absorbing action of weakening the impact of the gas and taking away the heat of the gas to lower the temperature by being broken by the high pressure gas. Further, it is possible to protect the end face of the adjacent battery cell with the unbroken region of the endothermic sheet 68 against the radiant heat of the gas.

Such an endothermic sheet 68 can be made of, for example, a silicone-based resin, a urethane-based material, or the like. The physical characteristics of the endothermic sheet 68 used in the embodiment are as follows.
(1) Hardness: 20AskerC
(2) Specific gravity: 1.9
(3) Tensile strength: 0.14 MPa

Growth rate: 100%
(4) Tear strength: 0.51 N / mm
(5) Thermal conductivity: 2.0 W / m · K
(6) Permittivity:
50Hz: 4.84
1kHz: 4.25
1MHz: 3.93
(7) Dissipation factor:
50Hz: 1.19 × 10 ^-1
1kHz: 4.61 × 10 ^-2
1MHz: 7.01 × 10 ^-3
(8) Volume resistivity: 4.5 × 10 ¹³ Ω ・ cm
(9) Breakdown voltage: 16.6 kV / mm
(10) Withstand voltage: 10.0 kV / mm
(11) Flame retardant V-0

In the above configuration, an example in which two battery blocks 40A and 40B are connected to form a battery assembly has been described, but the present invention does not limit the number of battery blocks to two, and may be one. Good. That is, the influence of gas and heat on the end face of one battery block can be reduced. Alternatively, the number of battery blocks may be 3 or more. In the power supply device for connecting three or more battery blocks, the battery blocks are arranged so as to be separated from each other with an insulating space 6. Further, at the interface connecting the battery blocks, the isolation plate 64 is arranged, and the isolation plate 64 is provided with the gas discharge direction regulation wall 65, so that the gas can be safely discharged at each connection interface. ..

The power supply device of the present invention can be suitably used as a power source for driving an electric vehicle such as an electric scooter, an electric cart, or an electric vehicle, and a power source for a power storage device for home or factory use.

100, 800, 900 ... Power supply device 1 ... Battery cell 2 ... Discharge valve 4 ... Insulation plate 6 ... Insulation space 8 ... Circuit board 9 ... Exterior case 13 ... End electrode; 13A ... First end electrode; 13B ... Second End electrodes 40, 940 ... Battery assembly 40A, 40B, 840A, 940A, 940B ... Battery block; 40a ... Facing surface 44 ... Battery holder; 44A ... Insertion; 44B ... Opening 45 ... Lead plate 61 ... Closing cover 64 , 864 ... Separation plate 65 ... Gas discharge direction regulation wall 66 ... Gas discharge path 68 ... Heat absorption sheet 962 ... Frame part 863, 963 ... Exhaust space

Claims (9)

A plurality of battery cells each having an outer can, one end face as an electrode, and a discharge valve for discharging gas when the internal pressure rises.
A battery block that holds the plurality of battery cells in a parallel posture so that one of the end faces is flush with each other.
At the end face of the battery block, at least a part is broken by the heat and pressure of the gas released when the discharge valve is opened, which is arranged on the end faces of the plurality of battery cells, and allows the gas to permeate. With a heat absorbing sheet
An isolation plate which is arranged at the end face of the battery block so as to be separated from the endothermic sheet and is released when the discharge valve is opened to break the endothermic sheet and receive the permeated gas.
Power supply with. The power supply device according to claim 1.
The endothermic sheet is at least partially broken by the gas released when the discharge valve is opened to allow the gas to permeate and proceed toward the isolation plate, and the gas is released to the isolation plate. A power supply device that prevents the diffused and reflected gas from reaching the end face of an adjacent battery cell in an unbroken area. The power supply device according to claim 1 or 2.
The endothermic sheet absorbs the heat of the gas by breaking at least a part of the gas released when the discharge valve is opened, and the heat of the gas is reflected by the isolation plate. A power supply device that prevents the radiant heat generated from reaching the end face of an adjacent battery cell in an unbroken region. The power supply device according to any one of claims 1 to 3, and further
A lead plate connecting each electrode of the plurality of battery cells is provided on the end face of the battery block.
The endothermic sheet is a power supply device that has insulating properties and is in close contact with the lead plate. The power supply device according to claim 4.
The endothermic sheet is a power supply device having one surface as an adhesive surface. The power supply device according to any one of claims 1 to 4.
A plurality of the battery blocks are connected,
A power supply device in which the isolation plate is interposed between the surfaces connecting the battery blocks. The power supply device according to any one of claims 1 to 6.
A power supply device in which the outer can of the battery cell has a cylindrical shape. The power supply device according to any one of claims 1 to 7.
A power supply device in which the endothermic sheet is made of a silicone-based resin. The power supply device according to any one of claims 1 to 8.
A power supply in which the isolation plate is made of mica, glass epoxy or aluminum.

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