JP2012160338A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique suppressing performance deterioration in a battery module.SOLUTION: A battery module 10 includes: a plurality of batteries 30 arranged with each other, each of which has an electrode body, a housing receiving the electrode body, and an external terminal provided outside the housing and electrically connected to the electrode body; a circuit board 12 having a base material 21 and a wiring layer 22 to which the external terminal is connected; a heat dissipation member 14 supporting regions of the batteries 30 on an opposite side to the external terminal; and a heat transfer mechanism 16 facilitating heat transfer between the base material 21 and the heat dissipation member 14.

Description

  The present invention relates to a battery module in which a plurality of batteries are connected.

  Generally, the electromotive force of a battery (single cell) is low, and it is about 4 V even in a lithium ion battery that is said to have a high electromotive force. Therefore, when a higher voltage is required, a plurality of batteries are connected in series and modularized. When a plurality of batteries are modularized as described above, a plate-shaped metal member may be used for connection between the electrodes of each battery.

  For example, a battery pack in which a plurality of batteries are connected by a metal member built-in substrate in which a metal member is built in an insulating base material has been devised (see Patent Document 1).

JP 2010-218797 A

  By the way, the battery may generate heat during charging and discharging. In particular, when a plurality of batteries are modularized, the amount of heat generated increases. Therefore, if appropriate heat dissipation is not performed, phenomena such as excessive temperature rise of the battery, temperature variation of each battery in the battery module, and uneven temperature distribution in the battery occur. These phenomena bring about a decrease and variation in battery performance, and shorten the battery life.

  This invention is made | formed in view of such a condition, The place made into the objective is to provide the technique which suppresses the performance degradation of a battery module.

  In order to solve the above problems, a battery module according to an aspect of the present invention is provided with an electrode body, a housing in which the electrode body is accommodated, an outside of the housing, and is electrically connected to the electrode body. A plurality of batteries each having an external terminal, a circuit board having a plurality of batteries arranged with each other, a base material, and a wiring layer to which the external terminals are connected; and a region of the plurality of batteries on the side opposite to the external terminals. A heat radiating member to be supported, and a heat transfer mechanism that facilitates heat transfer between the base material and the heat radiating member.

  According to this aspect, the battery is disposed between the base material and the heat dissipation member, and the heat of the battery is dissipated through the base material and the heat dissipation member. Further, even when the heat generation in the battery is uneven and the temperature of the base material that absorbed the heat of the battery and the temperature of the heat dissipation member are different, the heat between the base material and the heat dissipation member is reduced by the heat transfer mechanism. Therefore, the temperature of the battery can be made uniform.

  The heat transfer mechanism may include a metal member that connects the base material and the heat dissipation member.

  The heat transfer mechanism may have a heat transfer channel through which a heat medium that exchanges heat with the outside flows.

  The heat transfer channel may be configured to be able to exchange heat with at least one of the base material and the heat radiating member.

  The heat dissipating member may have a heat dissipating flow path through which a heat medium that exchanges heat with the outside flows.

  You may further provide the temperature detection part which detects the temperature of a battery module, and the control mechanism which controls the temperature of a thermal medium according to temperature.

  The control mechanism may include a cooling device that cools the heat medium when the temperature of the battery module is higher than a predetermined threshold.

  The control mechanism may include a heating device that heats the heat medium when the temperature of the battery module is lower than a predetermined threshold.

  According to the present invention, it is possible to suppress the performance degradation of the battery module.

It is a schematic diagram which shows schematic structure of the battery module which concerns on 1st Embodiment. It is sectional drawing which shows schematic structure of a battery. It is a side view of the battery module which concerns on 2nd Embodiment. It is a schematic diagram which shows schematic structure of the battery system suitable for the battery module which concerns on 2nd Embodiment. It is a figure which shows an example of the flowchart of the temperature control in a battery system.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

(First embodiment)
[Battery module]
FIG. 1 is a schematic diagram showing a schematic configuration of the battery module according to the first embodiment. The battery module 10 includes a plurality of batteries (single cells) 30 that are arranged apart from each other, and a circuit board 12 that electrically connects external terminals (the positive terminal 50 and the negative terminal 60) of the plurality of batteries, A heat dissipating member 14 that supports the bottom (lower) region of the plurality of batteries 30 opposite to the external terminals, and a heat transfer mechanism 16 that facilitates heat transfer between the circuit board 12 and the heat dissipating member 14. Prepare.

[Circuit board]
The circuit board 12 includes a metal substrate 18, an insulating resin layer 20, and a wiring layer 22. In the present embodiment, the metal substrate 18 and the insulating resin layer 20 constitute the base material 21.

  The metal substrate 18 is disposed on one main surface of the insulating resin layer 20. The metal substrate 18 is a member in which a metal such as Al or Cu having excellent thermal conductivity is formed into a flat plate shape, and improves the heat dissipation of the circuit board 12.

  The insulating resin layer 20 is a part of the base material 21 of the circuit board 12, for example, a melamine derivative such as BT resin, a liquid crystal polymer, an epoxy resin, a PPE resin, a polyimide resin, a fluorine resin, a phenol resin, a polyamide bismaleimide, or the like. The thermosetting resin is exemplified. From the viewpoint of improving the heat dissipation of the circuit board 12, the insulating resin layer 20 desirably has high thermal conductivity. For this reason, it is preferable that the insulating resin layer 20 contains silver, bismuth, copper, aluminum, magnesium, tin, zinc, alloys thereof, and the like as a high thermal conductive filler.

  The wiring layer 22 is formed in a predetermined pattern on the other main surface of the insulating resin layer 20. The wiring layer 22 of the present embodiment is made of copper.

  Electronic components (not shown) are mounted on one main surface of the circuit board 12. The electronic component includes a semiconductor element such as an IC and a passive element such as a resistor and a capacitor. The electronic component constitutes a circuit unit that monitors the voltage and temperature of the battery 30 and controls the connection state of the battery 30. More specifically, the circuit unit monitors the voltage and temperature of each battery 30, and when the voltage or temperature indicates an abnormality, disconnects only the battery 30 or a plurality of batteries including the battery 30. It has a function to do.

  A battery 30 is connected to one main surface of the circuit board 12. Specifically, the external terminals (positive terminal 50 and negative terminal 60) of the battery 30 and the wiring layer 22 of the circuit board 12 are connected.

  The heat transfer mechanism 16 is a metal member 17 that connects the base material 21 of the circuit board 12 and the heat dissipation member 14. The metal member 17 according to the present embodiment is produced by bending a plate-like member. The material is preferably Al or Cu, for example. Thereby, the heat-transfer mechanism 16 can be comprised cheaply and simply.

  An insulating film 24 is provided between the heat dissipation member 14 and the lower surface of the battery 30. The material of the insulating film 24 is not particularly limited as long as the insulating property is satisfied.

[battery]
FIG. 2 is a cross-sectional view showing a schematic configuration of the battery 30. As shown in FIG. 2, the battery 30 includes an outer can (housing) 31 in which an electrode body 32 in which positive and negative electrodes are wound in a spiral shape is housed laterally with respect to the can axis direction of the outer can 31. The opening of the outer can 31 is sealed by the sealing plate 33. The sealing plate 33 is provided with a positive electrode terminal 50 and a negative electrode terminal 60 that protrude outward from the battery 30. The sealing plate 33 is formed with a gas discharge valve (not shown).

  The positive electrode terminal 50 is fitted into the positive electrode opening of the sealing plate 33 while being in contact with the gasket 34. The positive electrode terminal 50 is connected to the positive electrode tab member 53 on the battery inner side of the sealing plate 33. A recess 51 is provided at the end of the positive electrode terminal 50 fitted in the positive electrode opening of the sealing plate 33 such that a side wall is formed along the positive electrode opening of the sealing plate 33. The positive terminal 50 is fixed by caulking so that the edge part of the recessed part 51 spreads. The core part (not shown) of the positive electrode terminal 50 is made of aluminum, and a copper plating layer (not shown) covers the core part. An insulating plate 35 is provided between the positive electrode tab member 53 and the battery inner surface of the sealing plate 33. The insulating plate 35 and the gasket 34 are in contact with each other at the positive electrode opening of the sealing plate 33. Thereby, the positive electrode tab member 53 and the positive electrode terminal 50 are insulated from the sealing plate 33.

  The positive electrode tab member 53 is connected to the positive electrode current collector plate group 32 a protruding from one end face of the electrode body 32. The positive electrode current collector plate group 32 a is a bundle of a plurality of positive electrode current collector plates protruding from one end face of the electrode body 32.

  The negative electrode terminal 60 is fitted into the negative electrode opening of the sealing plate 33 while being in contact with the gasket 34. The negative electrode terminal 60 is connected to the negative electrode tab member 62 inside the sealing plate 33 on the battery side. A recess 61 is formed at the end of the negative electrode terminal 60 fitted in the negative electrode opening of the sealing plate 33 so that a side wall is formed along the negative electrode opening of the sealing plate 33. The negative terminal 60 is fixed by caulking so that the edge part of the recessed part 61 spreads. The entire negative electrode terminal 60 is made of copper. An insulating plate 35 is provided between the negative electrode tab member 62 and the battery inner surface of the sealing plate 33. In the negative electrode opening of the sealing plate 33, the insulating plate 35 and the gasket 34 are in contact with each other. Thereby, the negative electrode tab member 62 and the negative electrode terminal 60 are insulated from the sealing plate 33.

  The negative electrode tab member 62 is connected to the negative electrode current collector plate group 32 b protruding from the other end face of the electrode body 32. The negative electrode current collector plate group 32 b is a bundle of a plurality of negative electrode current collector plates protruding from the other end face of the electrode body 32.

  As described above, the battery 30 according to the present embodiment has the positive electrode terminal 50 and the negative electrode terminal 60 as external terminals electrically connected to the electrode body 32.

  In the battery module 10 shown in FIG. 1, the battery 30 is disposed between the base material 21 and the heat dissipation member 14, and the heat of the battery 30 is radiated through the base material 21 and the heat dissipation member 14. Further, when the heat generation in the battery is uneven and the temperature of the base material 21 that mainly absorbs the heat of the upper part of the battery 30 and the heat radiation member 14 that mainly absorbs the heat of the lower part of the battery 30 are different. The heat transfer mechanism 16 can easily move the heat between the base material 21 and the heat dissipation member 14.

  For example, in the battery 30, when the heat generation near the positive electrode terminal 50 and the negative electrode terminal 60 is larger than the heat generation at the bottom of the battery 30 (the lower region opposite to the terminal), the temperature of the base material 21 is higher than that of the heat dissipation member 14. It tends to be higher. In that case, the heat of the base material 21 can be easily transferred to the heat radiating member 14 by the heat transfer mechanism 16. That is, the temperature of the base material 21 can be lowered. As a result, the heat near the terminal of the battery 30 can be absorbed more, and the temperature near the terminal of the battery 30 can be lowered. Thereby, even if the heat generation inside the battery 30 is not uniform, the temperature of the battery can be made uniform.

  Further, if an appropriate heat dissipation structure is not adopted, the temperature of each battery may vary depending on the position in the battery module and the amount of heat generated. However, in the battery module 10 according to the present embodiment, the base material 21 is connected to the plurality of batteries 30, and the heat dissipation member 14 supports the plurality of batteries 30. And the variation in the temperature of each battery 30 can be reduced via the heat transfer mechanism 16.

  In the battery module 10 according to the present embodiment, the circuit board 12 physically connects the wiring layer 22 constituting the circuit board 12 to the positive electrode terminal 50 and the negative electrode terminal 60 of the battery 30. The terminal 50 and the negative electrode terminal 60 are also thermally connected.

  Therefore, the heat generated in the battery 30 is conducted from the positive terminal 50 and the negative terminal 60 to the metal substrate 18 through the wiring layer 22, and the heat is further transferred to the metal member 17, so that the heat dissipation member 14 on the bottom surface side of the battery 30. Can be conducted.

  Thus, since the circuit board 12 not only realizes electrical connection with the battery 30 but also has a heat dissipation function and a heat transfer mechanism at the same time, the heat of the battery module 10 as a whole is made uniform. In addition to being efficient, the batteries 30 can be easily combined.

  Note that the heat transfer mechanism 16 may have a pipe serving as a heat transfer flow path through which a heat medium that exchanges heat with the outside flows instead of the metal member 17. The heat medium is not limited to a liquid such as water or oil, but may be a gas. Thereby, even if it is a case where the emitted-heat amount of the battery 30 is large, sufficient heat dissipation is realizable.

  Moreover, you may use together the metallic member 17 and piping as a heat-transfer mechanism. In this case, it is preferable to arrange the pipe so as to contact the side surface of the metal member 17. Or you may arrange | position piping so that at least any one of the base material 21 or the heat radiating member 14 may be contact | connected. By arranging in this way, heat exchange between the heat medium flowing through the pipe and the metal member 17, the base member 21, the heat radiating member 14, and the like is efficiently performed.

(Second Embodiment)
FIG. 3 is a side view of the battery module according to the second embodiment. FIG. 4 is a schematic diagram showing a schematic configuration of a battery system suitable for the battery module according to the second embodiment. In FIG. 4, only the heat dissipating member having the piping among the battery modules is shown, and the others are not shown.

  Compared with the battery module 10 according to the first embodiment, the battery module 70 shown in FIG. 3 is greatly different in that the heat dissipation member that supports the lower part of the battery is provided with piping for cooling and heating. The pipe 14a is provided so as to meander inside the heat radiating member 14, and functions as a heat radiating flow path through which a heat medium that exchanges heat with the outside flows. Thereby, the heat dissipation of the heat radiating member 14 can be improved. Such piping may be provided on the circuit board 12.

[Battery system]
The battery system 100 shown in FIG. 4 includes a battery module 70, a temperature monitor 72 that controls the operation of each device based on the detected temperature of the battery module 70, and water as a heat medium in the battery module 70. A circulation pump 74 that circulates in the piping, a heat exchanger 76 that cools water as a heat medium, a heater 78 that heats water as a heat medium, a piping system 80 that circulates water, and a battery module 70 And a temperature sensor 81 for detecting the temperature of the battery module 70 at a predetermined location.

  The piping system 80 is connected to a discharge port 82 through which water is discharged from the battery module 10 and a delivery port 84 for sending water to the battery module 70. In addition, the piping system 80 includes a first piping 80a in which a heat exchanger 76 is provided in the middle, a second piping 80b in which a heater 78 is provided, and a third piping in which a circulation pump 74 is provided. It is comprised with the piping 80c. Both ends of the first pipe 80 a and the second pipe 80 b are connected by a three-way valve 86 and a three-way valve 88. The third pipe 80 c connects the three-way valve 88 and the delivery port 84.

  The open / close state of the three-way valve 86 and the three-way valve 88 is controlled by an instruction signal from the temperature monitor 72. The water discharged from the discharge port 82 circulates in the battery system 100 via either the first pipe 80a or the second pipe 80b by the action of the circulation pump 74.

  Since the battery module 70 according to the present embodiment transfers heat between the battery 30 and the heat medium in the pipe 14a, for example, the heat of the battery 30 is transmitted to the heat medium, so that the temperature of the battery 30 is increased. The rise can be suppressed. Therefore, a decrease in battery performance due to temperature rise is suppressed, and the life of the entire battery module can be extended.

  In the battery module 70, the heat medium is discharged to the outside of the battery module via the pipe 14a, and the heat medium cooled by the external heat exchanger 76 is returned to the inside again. Therefore, by controlling the circulation of the heat medium with the circulation pump 74, the temperature of the battery can be adjusted even when the heat generation amount of the battery is large. Further, in the battery module 70, the heat medium heated by the external heater 78 can be circulated inside the battery module. Therefore, in a low temperature environment, the battery 30 can be heated to a temperature suitable for charging / discharging. As described above, the battery module 70 can easily radiate the heat of the battery 30 to the outside or heat the battery by the external heat.

  Further, since the battery module 70 is configured to circulate the heat medium in the pipe 14a, it is easy to keep the temperature of each battery 30 uniform. Therefore, the difference in performance degradation between the batteries 30 can be reduced, and the life of the battery module 70 as a whole can be extended.

[Temperature control]
Next, a method for controlling the temperature of the heat medium in the pipe according to the temperature of the battery module will be described. Below, the battery system 100 shown in FIG. 4 is demonstrated to an example.

  As described above, the battery system 100 includes a piping system for cooling or heating the heat medium outside the battery module 70. In the battery system 100, a temperature sensor 81 that detects the temperature of the battery module 70 is attached to the heat dissipation member 14. FIG. 5 is a diagram illustrating an example of a flowchart of temperature control in the battery system 100.

Temperature monitor 72 detects the temperature T of the battery module 70 by the temperature sensor 81 (S10), and compares it with a predetermined threshold value _{T 0} (S12). When the detected temperature T does not exceed the predetermined threshold (No in S12), the temperature monitor 72 continues to acquire the detected temperature of the temperature sensor 81 without operating the circulation pump 74. On the other hand, when the detected temperature T exceeds the predetermined threshold (Yes in S12), the temperature monitor 72 operates the circulation pump 74 (S14), and circulates the water in the heat radiating member 14 of the battery module 10. Since the circulating water dissipates heat by the heat exchanger 76 and is always cooled, the battery module 10 is kept at a certain temperature or lower.

  When the battery 30 is heated in a low temperature environment, the temperature monitor 72 may control the open / close state of the three-way valves 86 and 88 so that water passes through the heater 78 and operate the circulation pump 74.

  As described above, the battery system 100 includes the temperature monitor 72, the circulation pump 74, the heat exchanger 76, the heater 78, the temperature sensor 81, and the like as a control mechanism that controls the temperature of the heat medium according to the temperature.

  That is, the control mechanism has a heat exchanger 76 as a cooling device that cools the heat medium when the temperature of the battery module 70 is higher than a predetermined threshold. Therefore, the temperature rise of the battery 30 is suppressed and the life of the battery module 70 is extended.

  The control mechanism also includes a heater as a heating device that heats the heat medium when the temperature of the battery module 70 is lower than a predetermined threshold. Therefore, even in a low temperature environment, the battery 30 can be heated to a temperature suitable for charging / discharging.

  As described above, the battery system 100 can indirectly cool and heat the battery 30 through the heat transfer mechanism 16, the heat radiating member 14, the circuit board 12, and the like, and can adjust the temperature of the battery module 70 within a certain range.

  According to the battery module described above, the performance deterioration of the battery module is suppressed by appropriate temperature adjustment and temperature control, and the temperature of the battery module and the circuit board can be controlled. The performance degradation is suppressed. In addition, since the stress due to heat generated in the vicinity of the electrode can be relaxed, the mechanical reliability of the joint is improved.

  As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or replaced. Those are also included in the present invention. Further, it is possible to appropriately change the combination and processing order in each embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to each embodiment. Embodiments to which is added can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Battery module, 12 Circuit board, 14 Heat radiating member, 14a Piping, 16 Heat-transfer mechanism, 17 Metal member, 18 Metal substrate, 20 Insulating resin layer, 21 Base material, 22 Wiring layer, 24 Insulating film, 30 Battery, 31 Exterior Can, 32 electrode body, 50 positive terminal, 60 negative terminal, 70 battery module, 72 temperature monitor, 74 circulating pump, 76 heat exchanger, 78 heater, 80 piping system, 81 temperature sensor, 100 battery system.

Claims (8)

A plurality of batteries each having an electrode body, a housing in which the electrode body is accommodated, and external terminals provided outside the housing and electrically connected to the electrode body When,
A circuit board having a base material and a wiring layer to which the external terminals are connected;
A heat dissipating member that supports a region of the plurality of batteries opposite to the external terminal;
A heat transfer mechanism that facilitates the transfer of heat between the substrate and the heat dissipation member;
A battery module comprising:   The battery module according to claim 1, wherein the heat transfer mechanism includes a metal member that connects the base material and the heat dissipation member.   The battery module according to claim 1, wherein the heat transfer mechanism includes a heat transfer channel through which a heat medium that exchanges heat with the outside flows.   The battery module according to claim 3, wherein the heat transfer channel is configured to be able to exchange heat with at least one of the base material and the heat dissipation member.   5. The battery module according to claim 2, wherein the heat dissipating member has a heat dissipating flow path through which a heat medium that exchanges heat with the outside flows. A temperature detector for detecting the temperature of the battery module;
A control mechanism for controlling the temperature of the heat medium according to the temperature;
The battery module according to claim 3, further comprising:   The battery module according to claim 6, wherein the control mechanism includes a cooling device that cools the heat medium when the temperature of the battery module is higher than a predetermined threshold.   The battery module according to claim 6, wherein the control mechanism includes a heating device that heats the heat medium when the temperature of the battery module is lower than a predetermined threshold value.

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