JP2012221801A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool a secondary battery located at the center or near the center to reduce variations in the temperature distribution between multiple secondary batteries, assembly work hours, and removal work hours.SOLUTION: In a battery pack 10, multiple secondary batteries 11 are arranged parallel to each other. The battery pack 10 has a passage member 13 where a passage allowing a cooling medium to flow from a position corresponding to the center of arrangement positions of the multiple secondary batteries 11 to the surrounding area is formed. The passage member 13 is integrated with a terminal member 15 contacting with the respective terminals of the secondary batteries 11. Terminals are formed at both ends of each secondary battery 11.

Description

  The present invention relates to an assembled battery composed of a plurality of secondary batteries, and more particularly to an assembled battery characterized by its cooling structure.

  Secondary batteries are widely used as a power source because they can be recharged and used repeatedly. In recent years, secondary batteries have been required to be charged / discharged with a large current and increased in capacity, and assembled batteries composed of a plurality of secondary batteries have been used. Charging / discharging with a large current is accompanied by a large amount of heat generated inside the battery, and in the assembled battery, a large number of batteries are stored in a limited space, which increases the battery temperature and promotes deterioration of battery performance. There's a problem.

  In order to solve such problems, for example, a cooling structure for a lithium ion secondary battery has been proposed in which a cooling device for cooling positive and negative terminals protruding from the battery case is attached (see Patent Document 1). In the cooling device, a jacket surrounding the terminal is attached to the exterior of the battery case, and a refrigerant circulation device for circulating a liquid refrigerant in the jacket is provided. The refrigerant is supplied into the jacket from one end of the jacket, and is discharged out of the jacket from the other end of the jacket.

JP 2000-348781 A

  In an assembled battery, a plurality of secondary batteries are arranged in a limited space at regular intervals, so the secondary battery placed near the center does not dissipate heat smoothly due to the influence of surrounding secondary batteries, and the temperature Tends to rise. In the battery pack cooling device of Patent Document 1, the refrigerant is supplied into the jacket from one end of the jacket surrounding the terminal, and is discharged out of the jacket from the other end of the jacket. Therefore, the temperature of the refrigerant rises before the refrigerant reaches a position where the secondary battery arranged near the center where the temperature is likely to rise is cooled, and the cooling efficiency of the secondary battery arranged near the center is deteriorated. When the cooling efficiency of the secondary battery arranged near the center is deteriorated, the variation in temperature distribution (temperature difference between the plurality of secondary batteries) increases. In addition, since the battery pack cooling device of Patent Document 1 has a configuration in which a jacket having a cooling channel and a terminal (terminal member) of the battery pack are separate, the number of steps for assembly and removal increases.

  The present invention has been made in view of the above problems, and its purpose is to efficiently cool a secondary battery disposed in the center or near the center, thereby reducing variations in temperature distribution among a plurality of secondary batteries. An object of the present invention is to provide an assembled battery that can be reduced in size and can reduce the number of steps for assembly and removal.

  In order to achieve the above object, the invention according to claim 1 is an assembled battery in which a plurality of secondary batteries are arranged in parallel to each other from a position corresponding to the center of the arrangement position of the plurality of secondary batteries. A flow path member having a flow path through which a cooling medium flows is formed, and the flow path member is integrated with a terminal member that contacts each terminal of the secondary battery. Here, “the center of the arrangement position” does not mean the center exactly, but means the center and the vicinity of the center. In addition, “integrated with the terminal member” is not limited to a configuration in which the flow path member is formed of a conductive material, and a part of the flow member directly contacts the terminal of the secondary battery and plays the role of the terminal member. This means that the formed flow channel member and the terminal member are fixed with an adhesive or the like, or fixed together with a fastener, so that the flow channel member and the terminal member can be handled as a single unit. .

  In this invention, the cooling medium flowing through the flow path of the flow path member flows toward the periphery after cooling the secondary battery disposed near the center where the temperature is likely to rise, so the cooling medium is in the lowest temperature state. The secondary battery disposed near the center is cooled. Therefore, the secondary battery arranged at or near the center can be efficiently cooled to reduce the variation in temperature distribution among the plurality of secondary batteries, and the number of steps for assembly and removal can be reduced. .

  According to a second aspect of the present invention, in the first aspect of the present invention, the flow path member is disposed on both ends of the secondary battery. In this invention, the cooling effect is significantly improved as compared with the case where the flow path member is provided on one end side of the secondary battery.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the secondary battery is a secondary battery in which terminals are formed at both ends. Some secondary batteries have both a positive electrode terminal and a negative electrode terminal provided at one end of the secondary battery, and others have a positive electrode terminal and a negative electrode terminal provided separately at one end and the other end of the secondary battery. And when cooling a secondary battery with a flow path member, the direction which cools from the side in which a terminal exists has a big cooling effect. According to the present invention, in the assembled battery including the secondary battery in which the terminals are formed at both ends, the flow path member is disposed on both ends of the secondary battery, so that the cooling is performed efficiently.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the flow path member has the flow path formed in a spiral shape. Therefore, the cooling medium supplied to the position corresponding to the center of the arrangement positions of the plurality of secondary batteries surely flows outward from the center in order, and it is easy to suppress the temperature rise of all the secondary batteries.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the flow path member also serves as the terminal member. In this invention, the flow path member also serves as the terminal member, that is, the flow path member is formed of a conductive material, and a part of the flow path member directly contacts the terminal of the secondary battery and serves as the terminal member. Compared to the configuration in which the terminal member is fixed or fixed, the number of parts is reduced and the number of man-hours can be reduced.

  According to the present invention, it is possible to efficiently cool a secondary battery disposed at or near the center to reduce variation in temperature distribution among a plurality of secondary batteries, and to reduce assembly and removal man-hours. An assembled battery that can be provided can be provided.

(A) is a schematic perspective view which shows the relationship between the secondary battery and flow-path member of the assembled battery of 1st Embodiment, (b) The schematic front view of an assembled battery. (A) is a top view which shows the arrangement | positioning relationship between the flow path of a flow-path member and a secondary battery, (b) is a schematic diagram which shows the arrangement | positioning relationship between a secondary battery and a electrically-conductive member. The schematic front view of the assembled battery of 2nd Embodiment. (A) is a partially broken schematic front view of the assembled battery of 3rd Embodiment, (b) is a fragmentary perspective view of a electrically-conductive member. The schematic diagram of the terminal member of another embodiment. (A), (b), (c) is sectional drawing of the flow-path member of another embodiment.

(First embodiment)
A first embodiment embodying the present invention will be described below with reference to FIGS.
As shown to Fig.1 (a), (b), the assembled battery 10 has the some secondary battery 11 arrange | positioned in parallel mutually. The secondary battery 11 is a cylindrical battery. As shown in FIG. 1B, the secondary battery 11 has a positive terminal 11a protruding at one end and a negative terminal 11b at the other end (bottom). It is composed. That is, the secondary battery 11 of this embodiment is a secondary battery in which terminals are formed at both ends. The plurality of secondary batteries 11 are supported by the support member 12 in a state of being arranged in a grid pattern at predetermined intervals. The support member 12 is formed in a flat and substantially rectangular tube shape, and the secondary battery 11 is supported in a state of being fitted and positioned in a hole formed in the support member 12.

  The flow path members 13 are respectively disposed on both end sides of the secondary battery 11 supported by the support member 12. The flow path member 13 is formed of a material having good thermal conductivity, and is made of metal in this embodiment. As shown in FIGS. 1B and 2A, the flow path member 13 is fixed to the support member 12 using a fastening member 14. The fastening member 14 is formed in a U-shaped side surface, and fixes the support member 12 and the flow path member 13 with the inner surface of the support member 12 and the surface of the flow path member 13 opposite to the secondary battery 11 interposed therebetween. To do. In addition, illustration of the fastening member 14 and the terminal member mentioned later is abbreviate | omitted in Fig.1 (a). The support member 12 and the fastening member 14 may be made of metal, resin, or other materials.

  The flow path member 13 is formed with a flow path 13a through which a cooling medium flows from a position corresponding to the center of the arrangement positions of the plurality of secondary batteries 11 toward the periphery. In this embodiment, the flow path 13a is formed in a spiral shape. As shown in FIG. 1B, the flow path member 13 is integrated with a terminal member 15 that contacts each terminal of the secondary battery 11. In this embodiment, the terminal member 15 is integrally fixed to the flow path member 13 with an adhesive.

  The terminal member 15 is formed by fixing a conductive member 17 made of a metal having good electrical conductivity, for example, aluminum or copper, to a plate material 16 made of an electrically insulating resin having good thermal conductivity. ing. The conductive member 17 is fixed to the plate material 16 using, for example, an adhesive. As shown in FIG. 2B, the conductive member 17 is formed in a shape (meandering shape) that can be in contact with the positive terminals 11a of all the secondary batteries 11 arranged in a grid pattern, and one end of the conductive member 17 is a plate 16. A wiring connecting portion 17a is formed so as to protrude from the side. A wiring 18a is connected to the wiring connecting portion 17a. 2B shows the terminal member 15 electrically connected to the positive electrode terminal 11a of the secondary battery 11, the terminal member 15 electrically connected to the negative electrode terminal of the secondary battery 11 is also shown. It is constituted similarly.

  When the assembled battery 10 is assembled, the plurality of secondary batteries 11 are positioned and fixed by the support member 12, and then the flow path member 13 is fixed to the upper outer surface and the lower outer surface of the support member 12 by using the fastening members 14.

Next, the operation of the assembled battery 10 configured as described above will be described.
The assembled battery 10 can be used alone, but when used as a high-capacity, high-voltage power supply device for driving a motor such as an electric vehicle such as an electric vehicle, a plurality of assembled batteries 10 are connected in series. Used in connection with. In addition, when connecting the assembled battery 10 in series, the wiring 18a to which the positive electrode terminal 11a of the secondary battery 11 of the assembled battery 10 is connected is connected to the negative electrode wiring 18b of the other assembled battery 10 so that a plurality of the batteries 10 are connected. The assembled batteries 10 are connected in series.

  When the assembled battery 10 is used, each flow path member 13 is connected to a circulation path of a refrigerant circulation device that circulates the cooling medium, and the cooling medium is circulated and used. A liquid (for example, water) is used as the cooling medium. The circulating cooling medium flows through the flow path 13 a of the flow path member 13 to cool the secondary battery 11, and then is cooled by a cooling device provided in the circulation path and supplied to the flow path member 13 again. Is done.

  When the assembled battery 10 is used, the secondary battery 11 generates a large amount of heat during rapid charging or rapid discharging. The cooling medium supplied from the inlet 13b to the flow path 13a of the flow path member 13 cools the secondary battery 11 arranged near the center where the temperature is likely to rise, and then flows toward the periphery. The secondary battery 11 arranged near the center is cooled in a low temperature state. Therefore, the secondary battery 11 disposed near the center is compared with the configuration in which the cooling medium in the state where the temperature of the other secondary battery 11 is increased by cooling the other secondary battery 11 is cooled near the center. The cooling effect is improved, and the cooling efficiency of the assembled battery 10 as a whole is also improved. In addition, variations in temperature distribution among the plurality of secondary batteries 11 are reduced.

According to this embodiment, the following effects can be obtained.
(1) In the assembled battery 10, a plurality of secondary batteries 11 are arranged in parallel to each other, and a flow path 13a in which a cooling medium flows from a position corresponding to the center of the arrangement position of the plurality of secondary batteries 11 toward the periphery is formed. The flow path member 13 is provided. Therefore, the secondary battery 11 arranged at or near the center can be efficiently cooled to reduce variations in temperature distribution among the plurality of secondary batteries.

  (2) The assembled battery 10 is integrated with a terminal member 15 in which the flow path member 13 is in contact with each terminal (the positive terminal 11a and the negative terminal 11b) of the secondary battery 11. Therefore, the number of steps for assembly and removal can be reduced as compared with the configuration in which the flow path member 13 is different from the terminal member 15.

  (3) In the assembled battery 10, the flow path member 13 is disposed on both ends of the secondary battery 11. Therefore, the cooling effect is greatly improved as compared with the case where the flow path member 13 is provided on one end side of the secondary battery 11.

  (4) The secondary battery 11 is a secondary battery in which terminals are formed at both ends. When cooling the secondary battery, since the cooling effect is greater when the cooling is performed from the side where the terminals are present, in combination with the cooling of the secondary battery 11 being performed from both ends of the secondary battery 11, The secondary battery 11 is cooled more efficiently than a secondary battery in which a positive electrode terminal 11a and a negative electrode terminal 11b are provided at one end.

  (5) The flow path member 13 has a flow path 13a formed in a spiral shape. Therefore, the cooling medium supplied to the position corresponding to the center of the arrangement positions of the plurality of secondary batteries 11 reliably flows outward from the center in order, and it is easy to suppress the temperature rise of all the secondary batteries 11.

  (6) The terminal member 15 has a conductive member 17 made of a metal having good electrical conductivity, for example, aluminum or copper, fixed to a plate material 16 made of an electrically insulating resin having good thermal conductivity. Is formed. Therefore, electrical insulation between the flow path member 13 and the terminal member 15 is ensured, and it is not necessary to perform an electrical insulation process on the flow path member 13. Moreover, there is no problem even if a conductive liquid such as water is used as the cooling medium.

(7) Since a liquid is used as a cooling medium, the cooling efficiency is higher than when a gas is used.
(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in that the flow path member 13 also serves as the terminal member 15. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, in this embodiment, the terminal member 15 is not separately formed, and a part of the flow path member 13 formed of a conductive material is in direct contact with the terminal of the secondary battery 11 to serve as the terminal member 15. That is, the flow path member 13 also serves as the terminal member 15. The flow path member 13 disposed on the side in contact with the positive electrode terminal 11a (upper side in FIG. 3) has a recess (not shown) formed at a position corresponding to each positive electrode terminal 11a. It is formed to contact. When using the assembled battery 10 of this embodiment, when using a liquid as the cooling medium, a liquid having electrical insulation is used as the cooling medium in order to prevent current from flowing through the circulation path. To do.

According to the second embodiment, in addition to the same effects as (1) to (5) and (7) of the first embodiment, the following effects can be obtained.
(8) The flow path member 13 also serves as the terminal member 15. That is, the flow path member 13 is formed of a conductive material, and a part of the flow path member 13 directly contacts the terminal of the secondary battery 11 to serve as a terminal member. Compared with the configuration fixed or fixed to the member 13, the number of parts can be reduced and the number of man-hours can be reduced.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. 4 (a) and 4 (b). In this embodiment, the structure for holding the secondary battery 11 which comprises the assembled battery 10 in the state arrange | positioned by predetermined spacing differs from the said 1st and 2nd embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4A, in this embodiment, the flow path member 13 is constituted by a separate member from the terminal member 15, but the terminal member 15 does not have an electrically insulating plate member 16, and is a conductive member. 19 only. The flow path member 13 is formed of an electrically insulating resin having good thermal conductivity, and a positioning portion 20 for positioning the upper end portion or the lower end portion of the secondary battery 11 is formed. The conductive member 19 is formed by pressing a metal plate, and a fitting portion 19a whose outer surface can be fitted and fixed to the positioning portion 20 and into which the end of the secondary battery 11 can be fitted on the inner surface is shown in FIG. As shown in b), it is formed in a grid pattern corresponding to the arrangement interval of the secondary batteries 11. In addition, a wiring connecting portion 19b is projected. Then, the outer surface of the fitting part 19 a is fixed to the flow path member 13 in a state where the outer surface of the fitting part 19 a is fitted to the positioning part 20, and is integrated with the flow path member 13. The plurality of secondary batteries 11 are held in a state where they are positioned at predetermined positions by both flow path members 13.

According to this 3rd Embodiment, in addition to the effect similar to (1)-(7) of 1st Embodiment, the following effects can be acquired.
(9) Since the positioning member 20 is provided in the flow path member 13, the support member 12 that supports the plurality of secondary batteries 11 in a state where the secondary batteries 11 are positioned at predetermined intervals becomes unnecessary, and the number of parts is reduced.

(10) Since the conductive member 19 is directly fixed to the flow path member 13, the plate member 16 is not necessary, and the number of parts is reduced as compared with the first embodiment.
The embodiment is not limited to the above, and may be embodied as follows, for example.

  ○ When the separately formed flow path member 13 and the terminal member 15 are integrated as in the first embodiment, a fastener is used instead of fixing the flow path member 13 and the terminal member 15 with an adhesive. May be fixed together. Examples of the fastener include bolts and nuts, screws, clips that are clamped by elastic force, and the like.

The spiral shape of the flow path 13a is not limited to a substantially square shape as a whole, and may be a circular shape or a polygonal shape.
The secondary battery 11 is not limited to a cylindrical battery, and may be a square battery, for example.

  The secondary battery 11 is not limited to a secondary battery in which terminals are formed at both ends, and may be a secondary battery in which a positive electrode terminal 11a and a negative electrode terminal 11b are formed at one end. In this case, as shown in FIG. 5, a single plate member 16 constituting the terminal member 15 is provided with a positive electrode conductive member 21a in contact with the positive electrode terminal 11a and a negative electrode conductive member 21b in contact with the negative electrode terminal 11b. It is done.

The flow path member 13 does not necessarily need to be disposed on both ends of the secondary battery 11, and may be configured to be provided only on one end of the secondary battery 11.
When using the secondary battery 11 provided with terminals at both ends, the conductive member 17 constituting the terminal member 15 is in a shape that can contact the positive terminal 11a and the negative terminal 11b of all the secondary batteries 11. Instead of the meandering shape as in the first embodiment, for example, it may be formed in a rectangular shape that is the same shape as the plate member 16 and the wiring connecting portion 17a may be formed so as to protrude from a part of the periphery.

The conductive members 17 and 19, the positive electrode conductive member 21 a, and the negative electrode conductive member 21 b constituting the terminal member 15 may be formed by plating instead of using a metal plate.
The shape of the flow path 13a through which the cooling medium flows from the position corresponding to the center of the arrangement positions of the plurality of secondary batteries 11 toward the periphery is not limited to the spiral shape. For example, as shown in FIG. 6A, a plurality of flow paths 13a formed around the center are communicated by a communication portion 13c, or a plurality of guides 22 are formed as shown in FIG. 6B. May be provided radially, and a plurality of flow paths 13a may be formed radially.

  The arrangement of the plurality of secondary batteries 11 may be in a single row. For example, as shown in FIG. 6C, the flow path 13a of the flow path member 13 is provided with the inlet 13b at a position corresponding to the center of the arrangement position of the plurality of secondary batteries 11, and is supplied from the inlet 13b. The medium flows separately on the left and right sides in FIG. 6 (c), is folded at both ends, and is discharged from an outlet 13d provided at the outer center. When the cooling medium is a gas, the outlet 13d may be provided at both ends of the flow path member 13 apart from the inlet 13b of the flow path 13a without providing the outlet 13d at the outer center. Even when the cooling medium is a liquid, the outlet of the flow path 13a may be provided at two places if the shape of the circulation path of the refrigerant circulation device is configured to receive the cooling medium from the two outlets of the flow path 13a.

  O The inlet 13b of the flow path 13a is not limited to the center of the arrangement position of the secondary battery 11 in a strict sense, but includes the case where it is provided near the center. For example, when the secondary batteries 11 are arranged in a grid pattern as in the first to third embodiments, when the number of the secondary batteries 11 constituting the columns and rows of the secondary batteries 11 is an even number, The position of the inlet 13b is set to a position corresponding to any of the four secondary batteries 11 arranged on the inner side, or is set to an intermediate position between the two secondary batteries 11 adjacent to the four secondary batteries 11. Also good.

  The plurality of secondary batteries 11 constituting the assembled battery 10 are not limited to a configuration in which all the secondary batteries 11 are connected in parallel and connected to a common plus terminal and minus terminal. For example, the secondary battery 11 provided with the positive electrode terminal 11a and the negative electrode terminal 11b at one end is used, and the terminal member 15 has a conductive member that connects each secondary battery 11 in series, or is connected in series. Alternatively, a set of a plurality of secondary batteries 11 may be connected in parallel.

  ○ When the assembled battery 10 is used, the secondary battery 11 is cooled not only with the cooling medium flowing through the flow path member 13 but also with a cooling gas (air) on the outer surface of the secondary battery 11 constituting the assembled battery 10. You may make it contact positively. For example, the assembled battery 10 is accommodated in a housing having an intake duct and an exhaust duct, and air is supplied from the intake duct into the housing and exhausted from the exhaust duct by a blowing means such as a fan or a blower. You may make it the structure which blows air with a ventilation means, without providing a housing.

The following technical idea (invention) can be understood from the embodiment.
(1) In the invention according to any one of claims 1 to 4, the terminal member is a plate material made of an electrically insulating resin having good thermal conductivity and good electrical conductivity. A conductive member made of metal is fixedly formed.

  DESCRIPTION OF SYMBOLS 10 ... Assembly battery, 11 ... Secondary battery, 11a ... Positive electrode terminal as a terminal, 11b ... Negative electrode terminal as a terminal, 13 ... Channel member, 13a ... Channel, 15 ... Terminal member.

Claims (5)

In an assembled battery in which a plurality of secondary batteries are arranged in parallel to each other,
A flow path member formed with a flow path through which a cooling medium flows from a position corresponding to the center of the arrangement positions of the plurality of secondary batteries toward the periphery, and the flow path member is connected to each terminal of the secondary battery. An assembled battery characterized by being integrated with a contact terminal member.   The assembled battery according to claim 1, wherein the flow path member is disposed on both ends of the secondary battery.   The assembled battery according to claim 1 or 2, wherein the secondary battery is a secondary battery in which terminals are formed at both ends.   The assembled battery according to any one of claims 1 to 3, wherein the flow path member has the flow path formed in a spiral shape.   The assembled battery according to claim 1, wherein the flow path member also serves as the terminal member.

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