JP2004362958A - Battery module - Google Patents

Abstract

Provided is a battery module having a configuration for easily detecting a battery voltage and a battery temperature of a large number of unit cells.
SOLUTION: In a wind tunnel case 2 in which a cooling air flow passage is formed, battery units 4 in which two unit cells are connected in series and one end thereof is formed with a connection part of positive and negative electrodes are arranged in parallel. Both ends are exposed and accommodated. By attaching the end plates 3a and 3b to both side surfaces of the wind tunnel case 2, the contact pieces and the temperature sensor contact the end of the battery unit 4 to detect the battery voltage and battery temperature of each of the cells 10a to 10b. Can be.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a number of relatively high-capacity, high-output secondary batteries are connected in series to constitute a higher-power battery power supply. In particular, the battery voltage and battery temperature of each secondary battery are individually detected. And a battery module having a feature in a configuration for performing battery control.
[0002]
[Prior art]
The characteristics of a secondary battery change depending on the battery temperature. Particularly, when a large number of cells are connected in series to form a battery module, a change in characteristics of even a single cell affects the entire battery. It is necessary to detect the battery temperature and control the battery cooling means so that the battery temperature is equalized. Further, in order to control the charging and discharging of the secondary battery, it is necessary to detect the battery voltage and the battery temperature of each unit cell, and it is also necessary to control the abnormality, overcharge, overdischarge, etc. of each unit cell. Requirements. In particular, it is an indispensable requirement when a large number of high-capacity, high-output secondary batteries are combined to constitute a battery power source that requires a large driving power such as an electric vehicle, a hybrid vehicle, and an electric device.
[0003]
In order to detect the battery voltage and battery temperature of each unit cell, it is necessary to connect a lead between the positive electrode and the negative electrode of each unit cell and provide a temperature sensor for each unit cell. If the number of cells is small, this is easy, but if the number of cells is large, a lot of man-hours will be required to arrange lead wires and arrange temperature sensors. And increase costs.
[0004]
In a battery module configured by integrating a large number of cells, a plurality of cells are connected in series in order to realize a configuration for detecting a battery voltage and a battery temperature without increasing the number of steps as a battery module. A battery power supply device is known in which a battery unit is formed by providing a temperature sensor for each unit cell, and a plurality of battery units are connected in series and held integrally (see Patent Document 1). For the detection of the battery voltage, a method of embedding lead wires in a holder that holds a plurality of battery units connected in series and holding them is applied.
[0005]
[Patent Document 1]
JP-A-10-270095 (pages 3 to 5, FIG. 10)
[0006]
[Problems to be solved by the invention]
However, in the above prior art, since the battery unit is regarded as one battery, the battery voltage can be detected only in the unit of the battery unit, and the battery voltage of each unit cell cannot be detected. In order to detect the battery voltage of each cell, it is necessary to draw out the lead wire from the connection portion of each cell connected as a battery unit, which not only complicates the configuration of the battery unit but also connects the lead wires. A large number of man-hours are required for the processing.
[0007]
An object of the present invention is to provide a configuration for detecting a battery voltage and a battery temperature of each unit cell when connecting a large number of unit cells in series to form a battery module, and connecting lead wires to each unit cell. An object of the present invention is to provide a battery module having a structure that can be realized without using a battery module.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a battery module according to the present invention is characterized in that the opening end of a bottomed cylindrical battery can that houses a power generating element is sealed by a sealing plate having an electrode terminal protrudingly formed at the center, and the electrode terminal and the battery are sealed. The battery positive electrode and the battery negative electrode are divided into cans to form a unit cell. The two unit cells are connected in series and connected in series in the cylindrical axial direction, and the battery can is connected to a unit cell having an electrode terminal at an end. A battery unit was formed by providing a battery can extension connected to the electrode terminal forming surface, a plurality of the battery units were arranged in parallel, and openings for exposing both end faces of each battery unit to the outside were formed. A connection body accommodated in an outer case and connected to the electrode terminal and the bottom surface of the battery can to connect a plurality of battery units in series and / or in parallel, respectively, and makes contact and conduct with the extension portion of the battery can and the bottom surface of the battery can. Duplicate And a plurality of temperature sensors abutting the electrode terminal forming surface of each cell or the bottom surface of the battery can, and a lead wire connected to the contact piece or the temperature sensor. It is characterized by being attached to the opening forming surface.
[0009]
According to the above configuration, the battery unit in which two unit cells are connected in series is provided with the battery can extension connected to the battery can on the electrode terminal forming surface of the unit cell where the electrode terminal is located at the end. Therefore, when a plurality of battery units are alternately arranged in parallel with their directions reversed and connected in series, the voltage between the positive and negative electrodes of each cell can be detected from the contact piece that contacts the end. That is, in the unit cell in which the electrode terminal is located at the end, the battery voltage can be detected between the electrode terminal on the electrode terminal forming surface and the battery can extension. In addition, since the electrode terminal is connected to one of the battery cans of the same battery unit in the unit cell in which the bottom of the battery can is located at the end, the battery voltage is calculated from the voltage between the battery can extension and the bottom of the battery can. Can be detected. Therefore, the battery voltage and battery temperature of all the cells can be obtained from the end plates in contact with both ends of the battery unit, and it is not necessary to route the lead wires to detect the battery voltage and the battery temperature, and a large number of cells can be obtained. The number of manufacturing steps for the combined battery module can be reduced, and the cost can be reduced.
[0010]
In the above configuration, the end plate is formed by insert molding in which the contact surface of the contact piece and the heat-sensitive surface of the temperature sensor are externally exposed, and each of the contents is housed in a resin, so that the contact portion is displaced by vibration or impact. The battery module can be configured to be fixed in a state in which the battery module does not cause any abnormality even when the battery module is mounted on a moving body such as an automobile.
[0011]
In addition, the battery can extension is provided with an insulating plate mounted on the electrode terminal forming surface with the electrode terminal penetrating therethrough, and mounted on the insulating plate with the electrode terminal penetrating therethrough in the cylindrical axis direction of the cell. By configuring the extension portion to include an extension cap that is crimped to the battery can, it is possible to provide the battery can extension portion on the electrode terminal forming surface without displacing, and to be configured in a unitary cell can do.
[0012]
Further, when the contact piece and the temperature sensor are housed in a common container, the number of steps for attaching the contact piece and the temperature sensor to the end plate can be reduced, and a reliable contact structure can be obtained.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to facilitate understanding of the present invention. Note that the present embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
[0014]
The present embodiment shows an example in which 20 unit cells configured as cylindrical lithium ion secondary batteries are connected in series to form a battery module with a battery capacity of 13 Ah.
[0015]
FIG. 1 shows an external view of a battery module 1 according to an embodiment. Twenty single cells are accommodated in a wind tunnel case (exterior case) 2 composed of an upper case 21 and a lower case 22, and they are vented. It is configured so that it can be cooled by the air supplied from 23. On both side surfaces of the wind tunnel case 2, end plates 3 a and 3 b containing means for detecting the battery voltage and the battery temperature of each of the 20 unit cells are mounted.
[0016]
FIG. 2 is an exploded view of the wind tunnel case 2 and the end plates 3a and 3b. Twenty single cells 10a to 10t are formed in a battery unit 4 which is connected two by two in the cylindrical axis direction and connected in series. The ten battery units 4 are further connected in series. The wind tunnel case 2 accommodating the ten battery units 4 is provided with two cooling ventilation passages 13 for cooling the unit cells 10a to 10t, and when an explosion-proof valve provided for the unit cells 10a to 10t is activated. And three exhaust passages 14 for discharging the exhaust gas. In addition, a string-shaped gasket 11 is mounted on the arc-shaped battery support portion 12 that supports the battery units 4 in a state of being arranged side by side with a gap provided between the adjacent battery units, and is mounted thereon. The battery unit 4 separates the cooling ventilation passage 13 from the exhaust passage 14.
[0017]
As shown in FIG. 3, the open ends of the bottomed cylindrical battery can 15 accommodating the power generating element are sealed by a sealing plate 16, and a screw hole is formed in the center of the sealing plate 16. A negative electrode terminal (electrode terminal) 17 is provided. In order to form the unit cells 10a to 10t into two unit battery units 4, as shown in the unit cells 10a and 10b in FIG. 3, the connecting member 18 having one end joined to the sealing plate 16 of the unit cell 10b By joining the other end to the battery can 15 of the unit cell 10a, the two unit cells 10a and 10b are connected integrally and simultaneously connected in series. Further, as shown in FIG. 4, an insulating cap (insulating plate) 19 insulates the sealing plate 16 from the sealing side of the unit cell 10a where the negative electrode terminal 17 is located at one end of the battery unit 4. A state in which a positive electrode cap (battery can extension) 20 is attached by bringing the tip end into contact with 15, and a positive electrode (positive electrode cap 20) and a negative electrode (negative electrode terminal 17) are provided at one end of the battery unit 4 is formed. . Further, the unit cell 10b in which the bottom of the battery can 15 is positioned at the other end of the battery unit 4 is provided with a positive electrode terminal 24 that covers the bottom of the battery can 15 and has a screw hole formed in the center. The bottom cap 25 is joined.
[0018]
The unit cells 10c to 10t are also connected in units of two with the same configuration to form ten battery units 4. As shown in FIG. 5, the battery units 4 are arranged in parallel on the lower case 22 so that the directions in the cylindrical axis direction are alternately different, and the upper case 21 is put on the lower case 21 as shown in FIG. Are fixed by three bolts 26 screwed into the upper case 21 from the lower case 22 side and three bolts 26 screwed into the lower case from the upper case 21 side. Openings 27 are formed in both sides of the upper case 21 and the lower case 22 in an arc shape at positions corresponding to the respective battery units 4, so that the ends of the battery units 4 can be seen from both sides of the wind tunnel case 2. Become like
[0019]
On both sides of the wind tunnel case 2, ten battery units 4 are connected by connecting between the negative terminals 17 at both ends of the battery unit 4 exposed from the opening 27 and the positive terminals 24 of the adjacent battery units 4. Are connected, and the end plates 3a and 3b accommodating the temperature sensor 7 and the contact piece 6 that contacts the positive electrode cap 20 or the bottom cap 25 are attached.
[0020]
As shown in FIG. 7, the end plates 3 a and 3 b include a connection body 5, a sensor container 8 containing a contact piece 6 for detecting a battery voltage and a temperature sensor 7 for detecting a battery temperature. The extracted lead wire 28 is formed by insert molding in which a required portion is externally exposed and embedded in a resin. In the connection body 5, a contact portion with the negative electrode terminal 17 and the positive electrode terminal 24 and a contact portion with the bolt 26 are externally exposed, and an intermediate portion is positioned and sealed in resin. As shown in FIG. 8, the sensor container 8 is positioned and sealed in a resin by exposing the contact piece 6 and the heat transfer surface 29 to the temperature sensor 7 housed inside.
[0021]
As shown in FIG. 2, the end plates 3 a and 3 b include a main body plate 30 and a cover 31. By fixing the main body plate 30 to the side surface of the wind tunnel case 2 by bolts, the connection body 5 is connected to the negative electrode terminal 17 and the positive electrode terminal. The contact piece 6 and the heat transfer surface 29 are pressed against the positive electrode cap 20 or the bottom cap 25. By screwing bolts 26 into screw holes formed in the negative electrode terminal 17 and the positive electrode terminal 24, a series connection circuit capable of handling a large current is formed in the connection body 5. After the connection body 5 is fastened and fixed, the battery module 1 is completed by attaching the cover 31 to the main body plate 30. As shown in FIG. 9, the battery voltages of the cells 10a to 10t can be individually detected. A voltage detection circuit is configured.
[0022]
FIG. 9 shows a connection configuration for each of the cells 10 a to 10 t. The ten battery units 4 are connected in series by the connecting body 5, and the negative terminal 17 of the unit 10 a is connected to the negative input / output terminal of the battery module 1. Since the positive electrode terminal 24 of the unit cell 10t serves as the positive electrode input / output terminal of the battery module 1, the positive electrode external connection terminal hole 32 and the negative electrode external connection terminal hole 33 provided on the cover 31 of the end plate 3a apply the load to the battery module 1. Can be connected.
[0023]
Since the contact pieces 6 provided on the end plates 3a and 3b abut on the positive electrode cap 20 or the bottom cap 25 of each of the cells 10a to 10t, as shown in FIG. 6 and the battery voltage Et of the unit cell 10t can be individually detected by connecting the lead line 28 to the unit cell 6. In order to individually detect the battery voltage of a plurality of cells connected in series, it is usually necessary to wire a lead wire in the middle of the series connection, and when the number of cells increases, a large number of cells are integrated. In this configuration, there was a problem in that the lead wires had to be wired while the wiring length was increased, and at the same time, the man-hours required for wiring were greatly increased. Since the connection is made only by contacting the contact pieces 6 from both ends of the unit 4 and mounting the end plates 3a and 3b on the wind tunnel case 2, the configuration and man-hours for individual voltage detection are greatly reduced. Is done.
[0024]
Although not shown in FIG. 9, since the heat transfer surface 29 of the temperature sensor 7 abuts on each of the cells 10 a to 10 t simultaneously with the contact piece 6, the battery temperature of each of the cells 10 a to 10 t is individually set. Can be detected.
[0025]
The control means for controlling the charging and discharging of the battery module 1 individually monitors the battery voltage and the battery temperature of each of the cells 10a to 10t, and any one of the battery voltages has reached a voltage that leads to overcharge or overdischarge. When this is detected, charging or discharging is stopped. Further, the control means monitors the operating state and occurrence of an abnormality of the battery module 1 from the battery voltage, the battery temperature, and the charging / discharging current, and calculates an SOC (State of Charge), which is a stored amount of electricity with respect to the battery capacity, to load the battery module. Control the power supply to the Further, the control means controls the air blowing means such that the battery temperatures of the cells 10a to 10t are uniform and the optimum temperature state from the detected battery temperature.
[0026]
FIG. 10 shows an air blowing structure for cooling. Since the cells 10a to 10t are arranged side by side in the wind tunnel case 2 in an inclined state, the air supplied from the ventilation port 23 is supplied to the wind tunnel case 2. 2 flows from the lower case 22 side to the upper case 21 side from the gap between the arrays of the unit cells 10a to 10t arranged in parallel, and cools the unit cells 10a to 10t.
[0027]
In addition, an air guide plate 34 is provided on the vent 23 side of the cells 10a and 10b closest to the vent 23 to prevent the cells 10a and 10b from being excessively cooled by low-temperature air. ing. Although not shown, a damper for controlling the flow of air, a control device for controlling the amount of air blow, and the like are provided.
[0028]
In the embodiment described above, the configuration using 20 lithium ion secondary batteries as the unit cells 10a to 10t has been described, but the type and number of batteries can be arbitrarily set according to the purpose of use. Further, an example is shown in which a large number of unit cells 10a to 10t are connected in series. However, the invention is not limited to the series connection, and can be adapted to a parallel or series-parallel connection.
[0029]
【The invention's effect】
As described above, according to the present invention, when a battery module is configured using a large number of cells, the operating state of each cell is monitored, and the battery voltage and battery temperature required to control charging and discharging are determined. Since the configuration for detecting is simple, the cost can be reduced by reducing the number of manufacturing steps.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the external shape of a battery module according to an embodiment.
FIG. 2 is an exploded perspective view showing the structure of the battery module.
FIG. 3 is a cross-sectional view illustrating a configuration of a battery unit.
FIG. 4 is a perspective view showing a configuration in which a positive electrode cap is connected to a battery can on a sealing plate.
FIG. 5 is a perspective view showing a state where many battery units are arranged on a lower case.
FIG. 6 is a perspective view showing a state in which an upper case and a lower case are closed to form a wind tunnel case.
FIG. 7 is a perspective view illustrating attachment of a connector and a sensor container to each battery unit.
FIG. 8 is a perspective view showing a sensor container.
FIG. 9 is a circuit diagram showing a connection structure to a battery unit.
FIG. 10 is a perspective view showing a ventilation structure.
[Explanation of symbols]
1 Battery module 2 Wind tunnel case (exterior case)
3a, 3b End plate 4 Battery unit 5 Connector 6 Contact piece 7 Temperature sensor 8 Sensor container 10a to 10t Single cell 15 Battery can 16 Sealing plate 17 Negative electrode terminal (electrode terminal)
18 Connecting member 19 Insulating cap (insulating plate)
20 Positive electrode cap (battery can extension)
24 Positive terminal 25 Bottom cap

Claims (4)

The open end of the bottomed cylindrical battery can that houses the power generating element is sealed by a sealing plate with the electrode terminal protruding at the center, and the battery positive electrode and the battery negative electrode are distributed to the electrode terminal and the battery can, thereby forming a unit cell. Composed,
The two cells are connected in series in the cylindrical axis direction and connected in series, and a battery can extension connected to a battery can is provided on a surface of an electrode terminal on a unit cell having an electrode terminal located at an end. The unit is configured,
A plurality of the battery units are arranged in parallel, and housed in an outer case having openings formed to expose both end surfaces of each battery unit to the outside,
A connection body that is connected to the electrode terminal and the bottom of the battery can, respectively, and connects a plurality of battery units in series and / or in parallel; a plurality of contact pieces that contact and conduct with the battery can extension and the bottom of the battery can, respectively; An end plate containing a plurality of temperature sensors contacting the electrode terminal forming surface of the unit cell or the bottom surface of the battery can and the lead wire connected to the contact piece or the temperature sensor is attached to the opening forming surface of the outer case. A battery module, comprising: 2. The battery module according to claim 1, wherein the end plate is formed by insert molding in which a contact surface of the contact piece and a heat-sensitive surface of the temperature sensor are exposed to the outside, and each container is contained in a resin. The battery can extension is provided with an insulating plate mounted on the electrode terminal forming surface with the electrode terminal penetrating therethrough, and mounted on the insulating plate with the electrode terminal penetrating therethrough and extending in the cylindrical axis direction of the cell. The battery module according to claim 1, further comprising an extension cap whose part is crimped to the battery can. The battery module according to claim 1, wherein the contact piece and the temperature sensor are housed in a common container.

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