JP2019160502A - Battery device - Google Patents

Abstract

To provide a battery device that can raise the temperature of a battery with a simple configuration.SOLUTION: A battery device includes at least one battery and an energization path electrically connected to at least one battery, and the energization path includes a movable part configured to bendable in a direction intersecting with the energization direction in the energization path, and when the movable part bends as the temperature decreases, at least a part of the movable part is away from the energization path and the cross-sectional area of the energization path facing the energization direction decreases.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a battery device.

  As environmentally friendly vehicles, electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) are expected to grow in the future. Lithium ion batteries are used for EVs and PHEVs, but appropriate temperature management is necessary to maintain the characteristics and ensure the life of the lithium ion batteries. In particular, when the temperature of the lithium ion battery is low, the resistance is increased by slowing the rate of ion transport in the electrolyte existing inside the lithium ion battery or ion exchange at the active substance / electrolyte interface, and the expected performance. May not be available. For this reason, when the temperature of the battery is low, it is necessary to raise the temperature of the battery. Although not related to a lithium-ion battery, Patent Document 1 describes that a heating element is provided in a bus bar that connects each of a plurality of power storage elements in series in a battery device to quickly increase the temperature of the power storage elements. ing.

JP 2010-97923 A

  However, if a heating element for raising the temperature of the battery is provided, the operation mechanism of the heating element is required, the configuration of the battery device becomes complicated, and the weight and volume of the battery device increase. there were.

  In view of the above-described circumstances, at least one embodiment of the present disclosure aims to provide a battery device capable of raising the temperature of a battery with a simple configuration.

  The battery device according to at least one embodiment of the present invention includes at least one battery and an energization path electrically connected to the at least one battery, and the energization path intersects the energization direction in the energization path. A cross-sectional area of an energization path that is at least partially separated from the energization path and faces the energization direction by bending the movable part as the temperature decreases. Decreases.

  According to this configuration, when the temperature of the battery is low, a part of the cross-sectional area of the energization path is reduced, so that the Joule heat generated by increasing the electrical resistance is increased. can do.

  In some embodiments, the movable part may include a second material having a coefficient of expansion greater than that of the first material constituting the movable part. According to this configuration, when the temperature of the movable part is low, the contraction amount of the second material is larger than that of the first material, so that the movable part is bent so that at least a part of the movable part is separated from the energization path, Can reduce the cross-sectional area of a part of the energization path that faces the surface, and when the temperature of the movable part is high, the difference in the amount of contraction between the first material and the second material is small, thereby reducing the amount of bending of the movable part. Thus, the cross-sectional area of a part of the energization path that faces the energization direction can be increased.

  In some embodiments, the movable part may have an inner contact surface that contacts the energization path when the movable part is not bent, and the inner contact surface may be curved in a convex shape. According to this configuration, since the range of the movable part that is separated from the energization path changes finely according to the bending amount of the movable part, the energization path opposite to the energization direction is compared with the case where the inner contact surface is flat. The range of the area where the cross-sectional area is reduced can be finely adjusted.

  In some embodiments, the energization path may include a current collecting terminal connected to the current collector of at least one battery, and the current collecting terminal may include a movable part. The battery device may include a plurality of batteries, the energization path may include a bus bar that electrically connects the plurality of batteries, and the bus bar may include a movable portion. According to this structure, since a movable part is formed in the existing components like a current collection terminal and a bus bar, the enlargement of a battery apparatus can be suppressed.

  In some embodiments, the battery device further includes a control unit that controls charging / discharging of at least one battery, and the control unit at least until the temperature of the at least one battery rises to a preset required temperature. You may make it discharge in a pulse from one battery. According to this configuration, even when the battery is discharged and the cut-off voltage is reached immediately even when the battery is discharged, such as when the battery is started, the battery is raised by discharging the battery in pulses. Can be warmed.

  According to at least one embodiment of the present disclosure, when the temperature of the battery is low, a partial cross-sectional area of the energization path is reduced, thereby increasing Joule heat generated due to an increase in electrical resistance. The battery can be heated with Joule heat.

It is a perspective view of a battery device concerning Embodiment 1 of this indication. It is an enlarged front view of the area | region A of FIG. It is an enlarged front view of the area | region A of FIG. It is a top view of the battery apparatus which concerns on Embodiment 2 of this indication. FIG. 9 is a schematic configuration diagram of a battery device according to a third embodiment of the present disclosure. 12 is a graph for explaining an operation of discharge control from a battery in a battery device according to Embodiment 3 of the present disclosure.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the following embodiments are not merely intended to limit the scope of the present invention, but are merely illustrative examples.

(Embodiment 1)
As illustrated in FIG. 1, a battery device 1 according to Embodiment 1 of the present disclosure is connected to a battery 2 that is, for example, a lithium ion battery, and current collectors 3 and 4 on the negative electrode side and the positive electrode side of the battery 2. Current collecting terminals 5 and 6. The current collecting terminals 5 and 6 respectively constitute part of an energization path that is a path through which a current flows when the battery 2 is charged or discharged from the battery 2. The current collecting terminals 5 and 6 are electrically connected to the negative external terminal 20 and the positive external terminal 30, respectively.

  As shown in FIG. 2, the current collecting terminal 5 has an inner side surface 5 a that contacts the current collector 3 and an outer side surface 5 b that faces the inner side surface 5 a. The current collecting terminal 5 is formed with a notch 7 curved in a convex shape from the outer side surface 5b toward the inner side surface 5a. When the energizing direction, which is the direction in which current flows through the current collecting terminal 5, is represented by an arrow B, the notch 7 forms a movable portion 8 that can be bent in a direction intersecting the energizing direction B (the direction of the arrow C). The

  The movable part 8 includes a plate material 9 formed of a second material having an expansion coefficient larger than that of the first material constituting the movable part 8, and the plate material 9 is exposed on the outer side surface 5b and the plate material 9 is formed on the outer side surface 5b. Is included so as to be flush with each other. Although not shown in detail, as shown in FIG. 1, the current collecting terminal 6 has a movable portion 8 including a plate material 9, similarly to the current collecting terminal 5.

  In the current collecting terminal 5, when the first material is copper, an aluminum alloy, stainless steel SUS304, silver, tin or the like can be used as the second material. On the other hand, in the current collecting terminal 6, when the first material is aluminum, a magnesium alloy, a zinc alloy, or the like can be used as the second material.

Next, the operation of the battery device 1 according to the first embodiment will be described.
As shown in FIG. 1, when power is supplied from a battery device 1 to any electronic device (not shown), current flows from the battery 2 sequentially through the current collector 4 and the current collector terminal 6 to connect the electronic device and the external terminal 30. Power is supplied to the electronic device through the wiring (not shown), and current flows sequentially through the wiring (not shown), the current collector terminal 5, and the current collector 3 that connect the electronic device and the external terminal 20. However, when the temperature of the battery 2 is low, the expected performance may not be extracted from the battery device 1 in some cases.

  In the battery device 1 according to the first embodiment, when the temperature of the battery 2 is low, the temperatures of the current collectors 3 and 4, the current collector terminals 5 and 6, and the external terminals 20 and 30 are also low. Then, as shown in FIG. 2, since the contraction amount of the second material constituting the plate material 9 is larger than that of the first material constituting the current collecting terminal 5, that is, the movable portion 8, the movable portion 8 has its free end. The part 8a rotates, that is, bends in a direction away from the inner side surface 5a (in the direction of arrow C).

When the movable part 8 bends in the direction of the arrow C, a part of the movable part 8 is separated from the current collecting terminal 5 as shown in FIG. Part of the movable portion 8 is in a portion away from the current collector terminal 5, the cross-sectional area S opposite the current direction B is smaller than the cross-sectional area S ₀ of the other part. Since the electrical resistance increases as the cross-sectional area facing the energizing direction B decreases, the Joule heat generated in the region R where the cross-sectional area facing the energizing direction B decreases as the movable part 8 bends increases. The increased Joule heat is transferred into the battery 2 to increase the temperature of the battery 2 (see FIG. 1). In addition, since the movable part 8 in the current collection terminal 6 (refer FIG. 1) also performs the same operation | movement, the battery 2 can be heated up on the same principle.

  In Embodiment 1, the notch 7 is curved in a convex shape toward the inner side surface 5a, so that the inner contact surface 8b in contact with the current collecting terminal 5 is curved in a convex shape when the movable portion 8 is not bent. . According to this configuration, the range of the movable part 8 that is separated from the current collecting terminal 5 changes finely according to the amount of bending of the movable part 8, so that it is opposed to the energization direction compared to the case where the inner side surface 5a is flat. The range of the region R in which the cross-sectional area of the current collecting terminal 5 is reduced can be finely adjusted. The movable portion 8 in the current collecting terminal 6 has the same effect.

  When the temperature of the battery 2 rises to such an extent that expected performance can be extracted from the battery device 1, the temperature of the movable part 8 and the plate material 9 also rises due to such Joule heat. Then, the difference in contraction amount between the movable portion 8 and the plate member 9 is reduced, so that the movable portion 8 rotates in the direction in which the free end portion 8a approaches the inner side surface 5a (direction of arrow D). That is, the amount of bending of the movable part 8 decreases. Due to the rotation of the movable part 8 in the direction of arrow D, the area where the inner contact surface 8b of the movable part 8 and the current collecting terminal 5 are in contact with each other increases, and the range of the region R where the cross-sectional area facing the energizing direction B decreases. Reduce. As a result, an increase in the generated Joule heat can be suppressed. Eventually, the entire area of the inner contact surface 8b comes into contact with the side surface 5c of the current collecting terminal 5, and the portion of the movable portion 8 away from the current collecting terminal 5 disappears as shown in FIG.

  As described above, when the temperature of the battery 2 is low, a part of the cross-sectional area of the current collecting terminals 5 and 6 is reduced, so that the Joule heat generated by increasing the electrical resistance is increased. The battery 2 can be heated.

  In the first embodiment, the movable portion 8 is provided in both the current collecting terminals 5 and 6, but the movable portion 8 may be provided in only one of them. However, since the ion transport in the electrolyte on the negative electrode side or the ion exchange at the active substance / electrolyte interface has a larger influence on the temperature than the positive electrode side, only one of the current collecting terminals 5 and 6 is movable. When 8 is provided, it is preferable to provide the movable part 8 on the current collecting terminal 5 on the negative electrode side.

  In the first embodiment, the battery device 1 has one battery 2, but the battery device 1 may include a plurality of batteries 2 connected to each other by a bus bar. In this case, the movable part 8 may be provided on the current collecting terminals 5 and 6 of all the batteries 2, or the movable part 8 may be provided on at least one current collecting terminal 5 and 6 of the plurality of batteries 2. .

(Embodiment 2)
Next, the battery device according to the second embodiment will be described. The battery device according to the second embodiment is obtained by changing the position where the movable portion is provided with respect to the first embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As illustrated in FIG. 4, the battery device 1 according to the second embodiment of the present disclosure includes a plurality of batteries 2. In each of the plurality of batteries 2, the external terminal 20 and the external terminal 30 are connected by a bus bar 40. That is, the bus bar 40 electrically connects the batteries 2 and constitutes a part of an energization path that is a path through which a current flows when the battery 2 is charged or discharged from the battery 2.

  When there are a plurality of bus bars 40, the movable portion 8 having the same structure as that of the first embodiment is provided on each of at least one side edge thereof. However, the two movable parts 8 provided in one bus bar 40 are provided so that the extending directions of the cuts 7 are opposite to each other. Similar to the first embodiment, the movable portion 8 is configured to be bendable in a direction intersecting the energizing direction B in the bus bar 40 (direction of arrow C). Other configurations are the same as those of the first embodiment.

  Also in the second embodiment, as in the first embodiment, when the temperature of the battery 2 is low, the temperature of the bus bar 40 is low, so that the movable portion 8 bends in the direction of the arrow C, so that a part of the bus bar 40 is obtained. There is a region where the cross-sectional area facing the energization direction is reduced. Since the generation amount of Joule heat in this region is larger than that of the other parts based on the same principle as that of the first embodiment, the battery 2 can be heated by transferring the increased Joule heat into the battery 2. it can. The principle that the movable part 8 rotates in the direction of the arrow D when the temperature of the battery 2 rises is the same as in the first embodiment. Thus, even if the movable part 8 is provided in the bus bar 40, the same effect as that of the first embodiment can be obtained.

(Embodiment 3)
Next, a battery device according to Embodiment 3 will be described. The battery device according to the third embodiment is obtained by adding a control operation for discharging from the battery 2 to each of the first and second embodiments. In the following, the third embodiment will be described with a configuration in which the control operation for discharging from the battery 2 is added to the configuration in the first embodiment. However, the control operation for discharging from the battery 2 is added to the configuration in the second embodiment. Form 3 may be configured. Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the battery device 1 according to the third embodiment includes a battery 2, a temperature sensor 51 that detects the temperature of the battery 2, a switch 52 that is provided in the energization path of the battery 2, and a temperature sensor 51. And an ECU 50 that is a control unit electrically connected to each of the switches 52. Other configurations are the same as those of the first embodiment.

  If the temperature of the battery 2 is low as at the time of starting the battery 2, even if the battery 2 is discharged, the cut-off voltage is reached immediately, and the discharge may stop immediately. Then, even if the movable part 8 (see FIG. 2 or 3) is bent and the sectional area of a part of the current collecting terminals 5 and 6 (see FIG. 1) is reduced, no current flows, so no Joule heat is generated. The battery 2 cannot be heated.

  In the third embodiment, the ECU 50 compares the value detected by the temperature sensor 51 with a preset required temperature, and the ECU 50 repeatedly switches on / off of the switch 52 in a short period until the former reaches the latter, so that the battery 2 is discharged in pulses. At this time, as shown in FIG. 6, the lower limit voltage of pulsed discharge is set lower than the lower limit voltage during normal discharge. Due to such a pulsed discharge, current flows in a pulsed manner to the current collecting terminals 5 and 6, and the Joule heat is generated in the other part in the region R (see FIG. 3) where the movable part 8 is bent and the cross-sectional area is reduced. Therefore, the temperature of the battery 2 gradually increases. After the temperature of the battery 2 reaches the required temperature, the ECU 50 keeps the switch 52 turned on, so that normal discharge is performed.

  In this way, even when the battery 2 is discharged because the temperature of the battery 2 is low, such as when the battery 2 is started, even when the cutoff voltage is reached immediately, the battery 2 is discharged in a pulsed manner. The battery 2 can be heated.

  In Embodiments 1 to 3, the movable portion 8 has a shape including the inner contact surface 8b that is convexly curved toward the side surface 5c of the current collecting terminal 5. However, the movable portion 8 is not limited to this shape. It may have any shape.

  In the first embodiment, the movable portion 8 is provided on the current collecting terminals 5 and 6, and in the second embodiment, the movable portion 8 is provided on the bus bar 40. However, the present invention is not limited to these embodiments. Other than the current collecting terminals 5 and 6 and the bus bar 40, the movable portion 8 may be provided at an arbitrary position in the energization path.

DESCRIPTION OF SYMBOLS 1 Battery apparatus 2 Battery 3 Current collector 4 (on the positive electrode side) Current collector 5 (on the negative electrode side) Current collector terminal (energization path)
5a Inner side surface 5b (of the current collecting terminal) Outer side surface 5c (of the current collecting terminal) Side surface 6 (of the current collecting terminal) Current collecting terminal (energization path)
7 Notch 8 Movable part 8a Free end part 8b (of movable part) Inner contact surface 9 (of movable part) Plate material 20 External terminal 30 External terminal 40 Bus bar (energization path)
50 ECU (control unit)
51 Temperature sensor 52 Switch B Energizing direction R Area where cross-sectional area is reduced

Claims (6)

At least one battery;
An energization path electrically connected to the at least one battery,
The energization path includes a movable part configured to bendable in a direction intersecting the energization direction in the energization path, and the movable part bends as the temperature decreases, so that at least one of the movable parts. A battery device in which a cross-sectional area of the energization path facing away from the energization path and facing the energization direction decreases.   The battery device according to claim 1, wherein the movable part includes a second material having an expansion coefficient larger than that of the first material constituting the movable part.   3. The battery device according to claim 1, wherein the movable portion has an inner contact surface that contacts the energization path in a state where the movable portion is not bent, and the inner contact surface is curved in a convex shape. .   4. The battery device according to claim 1, wherein the energization path includes a current collecting terminal connected to a current collector of the at least one battery, and the current collecting terminal includes the movable portion. . The battery device includes a plurality of batteries,
The battery device according to any one of claims 1 to 3, wherein the energization path includes a bus bar that electrically connects the plurality of batteries, and the bus bar includes the movable portion. The battery device further includes a control unit that controls charging / discharging of the at least one battery,
6. The control unit according to claim 1, wherein the control unit causes pulse discharge from the at least one battery until a temperature of the at least one battery rises to a preset required temperature. 6. Battery device.

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