JP3849184B2 - Battery module and battery pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery module and an assembled battery, and more particularly to an assembled battery battery module used as a power source in an electric vehicle or the like.
[0002]
[Prior art]
FIG. 9 is an external perspective view of an example of an assembled battery B used as a primary battery for a power source of a conventional electric vehicle.
As shown in FIG. 9, the assembled battery B includes a large number of battery modules 102 incorporated in a battery case 101, and the battery modules 102 are connected by a bus bar (connecting terminal) 103 made of copper or the like to be about 100V to 400V. DC voltage is obtained. The bus bar 103 is connected to a terminal of the battery module 102 via a screw.
Further, for safety reasons such as prevention of electric shock, each battery module 102 is covered with a cover (not shown).
[0003]
[Problems to be solved by the invention]
However, since a large number of heavy bus bars and screws are required to configure the assembled battery, the total weight of the assembled battery becomes large, and a large number of battery modules are assembled to obtain a high voltage DC voltage. The assembled battery is bulky. Therefore, the weight energy density and volume energy density of the assembled battery are low, which is not preferable as an assembled battery for an electric vehicle.
Further, when power is extracted from the assembled battery, heat is generated (particularly at high output), but heat cannot be sufficiently radiated for the cover.
[0004]
Furthermore, as shown in FIGS. 10A and 10B, when the assembled battery B is mounted on an electric vehicle, it is often mounted under the floor. In this case, since the assembled battery B must be thin, the heat dissipating air circulation part A becomes narrow and it is difficult to secure a sufficient heat dissipating route.
Accordingly, an object of the present invention is to provide a battery module and an assembled battery that are reduced in weight, can sufficiently dissipate heat, and have high weight energy density and volume energy density.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a cylinder having an insulator on an outer peripheral portion, and a plurality of power generation units that are externally fitted to the cylinder and insulated from each other by the insulator. A battery module comprising: a unit cell; and an outer cylinder case that integrally covers a plurality of unit cells fitted on the cylinder.
According to the first aspect of the present invention, for example, as shown in FIG. 1, a plurality of electrodes (unit cells) 5a, 5b, 5c are externally fitted to the cylindrical body 1, and the outside is covered with the outer cylindrical case 2, so that a battery module is provided. M is configured. If constituted in this way, a plurality of (for example, three) electrodes are built in one battery module M, and a high voltage (for example, 1.5 × 3 = 4.5 V) in one battery module M. Can be obtained.
[0006]
The invention according to claim 2 is characterized in that airtightness is ensured for each unit cell.
According to a third aspect of the present invention, as the airtightness securing means, a partition wall is disposed between the unit cells, and a contact portion between the outer peripheral portion of the partition wall and the inner surface of the outer cylinder case is caulked from the outside. It is characterized by.
According to a fourth aspect of the present invention, as the airtightness securing means, a partition wall is disposed between the unit cells, and a contact portion between the outer peripheral portion of the partition wall and the inner surface of the outer cylinder case is band-tightened from the outside. It is characterized by becoming.
[0007]
According to the second to fourth aspects of the invention, airtightness between the unit cells is ensured by caulking or band fastening. By ensuring this airtightness, liquid leakage and gas leakage do not occur between the unit cells, and even if an abnormality occurs in one unit cell, other unit cells are not adversely affected.
[0008]
Further, the invention described in claim 5 is characterized in that a coolant is caused to flow through the cylindrical body.
According to invention of Claim 5, the temperature rise of a battery module can be prevented by flowing a refrigerant | coolant (for example, cool air of an air conditioner) through a cylinder.
[0010]
The invention according to claim 6 is characterized in that at least both ends of the battery module according to any one of claims 1 to 5 are held.
According to the invention described in claim 6, for example, as shown in FIG. 3, at least both ends of each battery module according to any one of claims 1 to 5 are fixedly held by the support plates 11b and 11d. If it does in this way, a battery module can be fixed firmly and rigidity can be secured even if it constitutes an assembled battery.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiment.
[0012]
(1) First Embodiment FIG. 1 is a longitudinal sectional view of a battery module M of this embodiment, FIG. 2 (A) is a perspective view of the main part of the battery module M, and FIG. 2 (B) is a top view. It is.
As shown in FIGS. 1, 2A, and 2B, the battery module M includes a cylindrical hollow core 1, electrodes (unit cells) 5a to 5c that are externally fitted to the hollow core 1, and current collectors. It is comprised by various members, such as lead part fixing member 7a-7d, the cylindrical outer cylinder case 2 which covers these various members, and the module connection members 3a and 3b etc. which mutually connect between the battery modules M.
[0013]
The hollow core 1 is configured such that an outer cylinder 1b made of an insulating material such as PE or PP is fitted on the outside of an inner cylinder 1a made of SUS, aluminum or the like. Plate-shaped intermodule connecting members 3a and 3b made of copper, aluminum, SUS, or the like are fitted into the upper end side and the lower end side of the hollow core 1, respectively. The inter-module connection members 3a and 3b are electrically connected to a positive electrode module terminal 4a and a negative electrode module terminal 4b that are respectively fitted on the hollow core 1, respectively. The module terminals 4a and 4b are terminals for taking out the electric power of each battery module M.
[0014]
Between the module terminals 4a and 4b, three short cylinders are formed by winding an insulating material film such as PE or PP in a roll shape and sandwiching an active material for a battery between the wound films. Shaped electrodes (unit cells, power generators) 5a, 5b, 5c are externally fitted to the hollow core 1 at equal intervals.
[0015]
On the upper and lower end surfaces of the upper electrode 5a, a tongue-shaped current collecting lead 6a for positive electrode and a current collecting lead 6b for negative electrode for extracting electric energy from the electrode 5a are respectively arranged. Similarly, current collecting leads 6c and 6d are arranged on the upper and lower end surfaces of the center electrode 5b, and current collecting leads 6e and 6f are arranged on the upper and lower surfaces of the lower electrode 5c. The upper and lower end surfaces of each current collecting lead are electrically connected to the current collecting lead portion fixing member 7 and the electrode 5 described below by laser or welding.
[0016]
Between the module terminal 4a and the current collecting lead 6a disposed above, a half of a abacus ball made of copper, aluminum, SUS or the like for electrically connecting the module terminal 4a and the current collecting lead 6a. The current collecting lead portion fixing member 7a is externally fitted, and between the module terminal 4b and the current collecting lead portion 6f disposed below, a similar current collecting lead portion fixing member 7b in the upper half of the abacus ball is provided. It is fitted. A similar current collecting lead portion fixing member 7c is externally fitted between the current collecting lead portions 6b and 6c, and a similar current collecting lead portion fixing member 7d is provided between the current collecting lead portions 6d and 6e. It is fitted.
An insulating film 8 made of PE, PP, or the like is attached to the inner surface side of the outer cylinder case 2 that covers various members such as the electrodes 5a to 5c. The upper and lower ends of the outer cylinder case 2 are formed in a sealed state with respect to the module terminals 4a and 4b, respectively.
[0017]
The contact portions between the outer peripheral portions of the current collecting lead portion fixing members 7c and 7d and the inner surface of the outer cylindrical case 2 and the insulating film 8 are caulked from the outer peripheral portion of the outer cylindrical case 2, and the electrodes 5a, 5b, The portion including 5c is a unit (unit cell S), and the airtightness of each unit cell S is ensured. That is, each of the current collecting lead portion fixing members 7a to 7d including the current collecting lead portion fixing members 7a and 7b at both upper and lower ends serves as a partition for separating each unit cell S (electrode) with airtightness.
[0018]
FIG. 3 is a longitudinal sectional view of an assembled battery B1 incorporating a large number (for example, 12) of battery modules M configured as described above, and FIGS. 4A, 4B, and 4C show the assembled battery. It is a perspective view of B1, and the figure of the example of arrangement | positioning of the battery module M at the time of seeing from the arrow Y direction, respectively.
[0019]
As shown in FIGS. 3, 4A and 4B, a strong box 11a is constituted by a structural member made of iron, SUS, aluminum or the like. The box 11a includes an upper support plate 11b, an intermediate support plate 11c, and a lower support plate 11d made of iron, SUS, aluminum, or the like, and the upper end of the hollow core 1 of each battery module M is supported by the support plates 11b and 11d. The lower end portions are fixed via insulating sleeves 12 respectively. The central part of each battery module M is fixed by a middle support plate 11c.
The battery modules M are connected in series by inter-module connecting members 3a and 3b, and assembled battery terminals 14 for connection to the outside are disposed at the left and right corners above the assembled battery B1.
Reference numeral 13 denotes an assembled battery case made of aluminum, SUS, iron or the like that covers the assembled battery B1.
[0020]
Next, the operation will be described.
The battery module M or the hollow core 1 has an upper end portion, a central portion, and a lower end portion that are supported by the upper support plate 11b, the middle support plate 11c, and the lower support plate 11d, respectively. Even if it is mounted on (A) and (B)), sufficient strength can be secured.
[0021]
Since, for example, three electrodes can be formed in the battery module M, the generated voltage of the battery module M per unit becomes high. That is, the conventional battery module shown in FIG. 10 has a voltage of 1.5V, whereas the battery module M of the present embodiment has a voltage of 1.5V × 3 = 4.5V. Therefore, according to the present embodiment, when the same voltage is generated, the weight energy and the volume energy can be improved because both the weight and the volume can be reduced.
[0022]
Of course, the number of electrodes in the battery module may be four or more.
Moreover, the battery module M can be cooled by flowing cooling air through the hollow portion of the hollow core 1. In particular, when the temperature rises in order to extract a large output from the battery module (for example, when climbing), for example, cold air for an air conditioner may be allowed to flow.
Furthermore, as shown in FIG. 4 (C), if the battery module M is shifted and arranged, the height H1 of the assembled battery can be further reduced.
[0023]
(2) Second Embodiment The difference between the present embodiment and the first embodiment is that an abnormality detecting means for detecting an abnormality of the battery module M is provided.
FIG. 5 is a longitudinal sectional view of the battery module M1 of this embodiment, and FIG. 6 is a block diagram of the abnormality detection circuit. In addition, the same code | symbol is attached | subjected to the already demonstrated part and duplication description is abbreviate | omitted.
[0024]
As shown in FIG. 5, abnormality detection circuits 21a, 21b, and 21c that detect an abnormality for each unit cell S are disposed on the inner surface side of the hollow core 1, and each circuit 21a, 21b, and 21c detects an abnormality. LED (light emitting diodes) 23a, 23b, and 23c that are turned on in the case are attached.
[0025]
Terminals 25a to 25d project from the inner surfaces of the current collecting lead portion fixing members 7a to 7d toward the inner surface of the hollow core 1, and between the terminals 25a to 25d and the abnormality detection circuits 21a to 21c, It is connected by connection cables 22a, 22b.
An optical sensor 26 made of a phototransistor or the like is disposed at the upper end of the hollow core 1 to detect lighting of the LEDs 23a, 23b, and 23c.
As shown in FIG. 6, a voltmeter V is connected to each unit cell S of the battery module M, and the detected value of the voltmeter V is A / D converted and input to the CPU. And LED23 is lighted via I / O from CPU.
[0026]
In this way, when the unit cell S is overcharged, overdischarged, or the cell temperature is abnormally increased, the LED 23 of the unit cell S corresponding to the abnormality is turned on, and the lighting light is detected by the optical sensor 26 to An alarm is issued through a buzzer (not shown). Therefore, when an abnormality occurs in the battery module, measures can be taken immediately.
In addition, since lighting of LED23 generate | occur | produces in the inside of the hollow core 1, it can detect easily even the light of weak light intensity. Further, since the abnormality detection circuit 21 is installed inside the hollow core 1, even if an abnormal external force is accidentally applied to the assembled battery B1, there is almost no possibility that the abnormality detection circuit 21 will fail.
[0027]
(3) Third Embodiment The difference between this embodiment and the first embodiment (see FIG. 4) is that a forced cooling means is provided.
As shown in FIG. 7, an intake duct 31 for introducing a refrigerant is disposed on the upper end side of the hollow core 1 of each battery module M, and the intake duct 31 passes through the introduction pipe 31 a from the intake duct 31 to each hollow core 1. Cold air from air conditioners, radiators, etc. flows in.
[0028]
A recovery duct 32 for recovering the refrigerant is disposed on the lower end side of the hollow core 1 of each battery module M, and the cooled exhaust gas is recovered via each recovery pipe 32a.
And it is made for cooling air to hit the battery module M from the outside at the time of driving | running | working of a normal electric vehicle (refer FIG. 11 (A)).
[0029]
Further, since the heat generation of the battery module M increases at the time of high output (for example, during climbing), the refrigerant flows through the route of the intake duct 31 → the introduction pipe 31a → the hollow core 1 → the recovery pipe 32a → the recovery duct 32 The battery module M is forcibly cooled. In this way, the battery module M is not overheated even at high output, and therefore a decrease in output can be prevented.
[0030]
(4) Fourth Embodiment In this embodiment, as shown in FIG. 8, a band 35 made of SUS or the like is wound and tightened from the outer periphery of the caulking portion of the outer cylinder case 2 so that the caulking does not loosen. It is a thing. In this way, the reliability of confidentiality for each cell is further improved.
It is also possible to fix the battery module M when assembling the assembled battery using the band 35 (see FIGS. 4A, 4B, and 4C).
[0034]
【The invention's effect】
As described above, according to the invention described in each claim, a plurality of unit cells for power generation are externally fitted to a cylinder, and the unit cells are covered with an outer cylinder case so that airtightness is maintained for each unit cell. Since the battery module is configured as described above, the weight energy and volume energy per battery module are improved, and the heat dissipation is improved because the ventilation inside the cylinder is good.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a battery module according to a first embodiment of the present invention.
FIG. 2A is a perspective view of a main part of the first embodiment, and FIG. 2B is a top view.
FIG. 3 is a longitudinal sectional view of an assembled battery configured by the battery module of the first embodiment.
4A is a perspective view of an assembled battery constituted by the battery module of the first embodiment, and FIGS. 4B and 4C are side views as seen from the direction of arrow Y. FIG.
FIG. 5 is a longitudinal sectional view of the second embodiment.
FIG. 6 is a block diagram of an abnormality detection circuit used in the second embodiment.
FIG. 7 is a longitudinal sectional view of the third embodiment.
FIG. 8 is a longitudinal sectional view of an essential part of the fourth embodiment.
FIG. 9 is an external perspective view of a conventional assembled battery.
FIG. 10A is a view showing a mounting position of an assembled battery in a conventional electric vehicle, and FIG. 10B is a perspective view of the assembled battery.
[Explanation of symbols]
B Batteries M Battery module 1 Hollow core 2 Case (outer cylinder case)
3 Inter-module connection member 4 Module terminal 5 Electrode (unit cell)
6 Current collecting lead portion 7 Current collecting lead portion fixing member 8 Insulating film 11a Box 11b, 11c, 11d Support plate 12 Sleeve 23 LED
26 Optical sensor 31 Refrigerant intake duct 32 Refrigerant recovery duct 35 Caulking band

Claims (6)

A cylinder comprising an insulator on the outer periphery;
A plurality of unit cells for power generation that are externally fitted to the cylinder and insulated from each other by the insulator;
An outer cylinder case that integrally covers a plurality of unit cells that are externally fitted to the cylinder;
A battery module comprising:   The battery module according to claim 1, wherein airtightness is ensured for each unit cell. 3. The airtightness securing means includes a partition wall disposed between the unit cells, and a contact portion between an outer peripheral portion of the partition wall and an inner surface of the outer cylinder case is caulked from the outside. Battery module. 3. The airtightness securing means includes a partition wall disposed between the unit cells, and a band contact portion between an outer peripheral portion of the partition wall and an inner surface of the outer cylinder case is externally fastened. The battery module described in 1.   The battery module according to claim 1, wherein a coolant is allowed to flow through the cylindrical body. 6. An assembled battery comprising at least both ends in the longitudinal direction of the battery module according to claim 1.

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