JP5132373B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module using a secondary battery and a battery pack including the same.

  In recent years, secondary batteries have been widely used as power sources for electric vehicles, hybrid electric vehicles, electric bicycles, or electric devices. For example, a lithium ion secondary battery, which is a non-aqueous secondary battery, has attracted attention as a power source for electric vehicles and the like because of its high output and high energy density.

  In general, a secondary battery includes a case formed in a flat rectangular box shape with aluminum or the like, an electrode group housed together with an electrolyte in the case, and an electrode provided in the case and connected to the electrode group And a terminal.

The case is relatively weak against a mechanical external force and may be deformed. Therefore, a battery pack in which a secondary battery is housed in a sealed case formed of a synthetic resin or the like has been proposed (for example, Patent Document 1). When a battery pack is configured by arranging a plurality of secondary batteries side by side, it is necessary to cover the entire group of secondary batteries with a strong exterior case. However, a battery pack using a battery pack having a sealed case as described above is used. In this case, a strong exterior case can be omitted, and the battery pack can be reduced in weight and the configuration can be simplified.
JP 2000-149893 A

  Usually, the secondary battery generates heat in accordance with the power feeding operation, and depending on the usage environment, it can be considered that the temperature becomes as high as about 50 ° C. At such a high temperature, the life of the secondary battery is reduced, so it is desirable to cool the secondary battery and suppress an excessive temperature rise. However, as described above, in the battery pack in which the secondary battery is housed in the sealed case, it is difficult to release the heat of the secondary battery to the outside, and the cooling performance is deteriorated.

  This invention is made | formed in view of the above point, The objective is to provide the battery module and battery pack which have high cooling performance and can prevent the lifetime reduction.

A battery module according to an aspect of the present invention has a case, a secondary battery having an electrode body housed in the case, a terminal connected to the electrode body and protruding from the case, and an insulating property. A housing that covers an outer surface of the secondary battery , and a circulation space is formed between the case of the secondary battery and the inner surface of the housing, the cooling medium being circulated. An inlet that guides the cooling medium to the circulation space; and an outlet that discharges the cooling medium that circulates through the circulation space. The inlet and the outlet gradually increase in size from the inside to the outside of the housing. It is formed to be large.

According to an aspect of the invention, wherein the housing has a guide rib for guiding the cooling medium flowing from the inlet to the outlet.

  According to the above configuration, it is possible to provide a battery module and a battery pack that have high cooling performance and can prevent a decrease in life.

  Hereinafter, a battery module according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an appearance of the battery module according to the first embodiment, FIG. 2 is an exploded perspective view showing the battery module, and FIGS. 3 and 4 show cross sections of the battery module.

  As shown in FIGS. 1 and 2, the battery module 10 includes a thin secondary battery 12 such as a lithium ion battery, and a flat rectangular box-shaped casing 14 that covers the entire outer surface of the secondary battery 12. And.

  As shown in FIGS. 2 to 4, the secondary battery 12 includes a flat rectangular box-shaped case 16 formed of aluminum or the like, an electrode body 18 housed in the case together with a nonaqueous electrolyte solution, and a case. 16 has a positive terminal 20a and a negative terminal 20b protruding from one end wall, here the top wall 16a. The electrode body 18 is formed in, for example, a flat rectangular shape in which a positive electrode plate and a negative electrode plate are wound in a spiral shape with a separator interposed therebetween, and further compressed in the radial direction. The positive electrode terminal 20 a and the negative electrode terminal 20 b are connected to the positive electrode and the negative electrode of the electrode body 18, respectively, and extend through the top wall of the case 16 in a liquid-tight manner. A gasket made of an insulator (not shown) is provided between the positive terminal 20a and the negative terminal 20b and the top wall 16a.

  As shown in FIGS. 1 to 4, the housing 14 has a rectangular box shape slightly larger than the secondary battery 12, and has an insulating material, for example, a synthetic resin such as ABS resin or polycarbonate. It is formed by. The housing 14 has a box-shaped main body 24 having one main surface opened, and a rectangular cover plate 26 covering the opening of the main body. The main body 24 has a rectangular main wall 24a, a pair of side walls 24b erected on both side edges of the main wall, and a top wall 24c and a bottom wall 24d erected along the upper and lower edges of the main wall. In preparation. A pair of openings 25 exposing the positive electrode terminal 20a and the negative electrode terminal 20b of the secondary battery 12 are formed in the top wall 24c of the housing 14.

  The cover plate 26 is screwed and fixed to the side wall 24b, the top wall 24c, and the bottom wall 24d of the main body 24, faces the main wall 24a of the main body with a gap, and closes the opening of the main body. The cover plate 26 constitutes the other main wall of the housing 14.

  The secondary battery 12 is housed in the housing 14, and the entire outer surface of the case 16 is covered with the housing 14. In the state of being housed in the housing 14, the secondary battery 12 has both side surfaces and upper and lower end surfaces of the case 16 facing the inner surfaces of the side wall 24 b, the top wall 24 c and the bottom wall 24 d of the housing 14, respectively. The positioning in the direction parallel to the main wall 24a of the housing 14 is performed. Further, the upper end portion and the lower end portion of the case 16 are sandwiched from both sides by the protruding portions formed on the inner surface of the main wall 24 a of the housing 14 and the protruding portions 25 a and 25 b formed on the inner surface of the cover plate 26. Yes. Thereby, the secondary battery 12 is positioned in the thickness direction of the housing 14. The positive terminal 20a and the negative terminal 20b of the secondary battery 12 are located in a pair of openings 25 formed in the top wall 24c of the casing 14, and project outward from the top wall 24c of the casing through these openings. .

  In a state where the secondary battery 12 is housed in the housing 14, one main surface 16 b of the case 16 is opposed to the inner surface of the cover plate 26 with a gap, and this gap causes a cooling medium, for example, cooling air. A distribution space 28a that can circulate is formed. Further, the other main surface 16c of the case 16 faces the inner surface of the main wall 24a of the main body 24 with a gap therebetween, and a circulation space 28b through which cooling air can flow is formed by this gap.

  The housing 14 has an inlet that guides cooling air to the circulation spaces 28a and 28b, and an outlet that discharges the cooling air that has circulated through the circulation space. In the present embodiment, the housing 14 is formed in an elongated slit-like inlet 30a formed along the side edge of the cover plate 26 and the side wall 24b of the main body 24, and extends along the side edge of the main wall 24a. It has an elongated slit-shaped inlet 30b. These inflow ports 30a and 30b communicate with the circulation spaces 28a and 28b, respectively. Each of the inflow ports 30a and 30b is formed so that the width gradually increases from the inside of the housing 14 toward the outside.

  The casing 14 is formed at the elongated slit-like outlet 32a formed along the other side edge of the cover plate 26 and the other side wall 24b of the main body 24, and along the side edge of the main wall 24a. It has an elongated slit-shaped outlet 32b that extends. These outlets 32a and 32b communicate with the circulation spaces 28a and 28b, respectively. Each of the outflow ports 32a and 32b is formed so that the width gradually increases from the inside of the housing 14 toward the outside.

  According to the battery module 10, cooling air supplied from a cooling fan or the like (not shown) flows into the housing 14 from the inflow ports 30a and 30b and circulates in the circulation spaces 28a and 28b. The cooling air flows around the secondary battery 12 to cool the secondary battery, and is then discharged to the outside of the housing 14 through the outlets 32a and 32b.

  According to the battery module 10 configured as described above, the strength of the secondary battery can be improved by covering the secondary battery 12 with the housing 14. When a battery pack is configured by stacking a plurality of battery modules, the casing 14 can be connected to form an outer case, and the battery pack can be reduced in weight and the configuration can be simplified. In addition, by forming circulation spaces 28a and 28b through which the cooling medium can be circulated between the secondary battery 12 and the casing 14, the cooling air flowing in from the inlet can be circulated around the secondary battery. The secondary battery can be sufficiently cooled. Since the secondary battery 12 is covered by the casing 14 having an insulating property, the insulation coating on the outer surface of the case of the secondary battery can be omitted, and as a result, the cooling performance of the secondary battery can be further improved. It becomes possible. Thereby, the excessive temperature rise of the secondary battery 12 can be prevented, and the lifetime reduction of a secondary battery can be prevented.

Furthermore, the inflow ports 30a and 30b and the outflow ports 32a and 32b of the housing 14 are formed so as to gradually widen from the inside of the housing toward the outside. Therefore, as shown in FIG. 3, even when the plurality of battery modules 10 are arranged side by side, even when the inflow port and the outflow port are opposed to each other in the thickness direction of the housing 14 due to dimensional tolerances or the like. The flow resistance of the cooling air does not increase, the cooling air flow rate does not decrease, and the cooling performance of the battery module can be ensured.
From the above, a battery module with high cooling performance and improved reliability can be obtained.

  In the first embodiment described above, the cooling medium can flow between one main wall of the casing and the secondary battery and between the other main wall of the casing and the secondary battery. Although the circulation space is formed, the present invention is not limited to this, and the secondary battery can be cooled by providing the circulation space between at least one main wall and the secondary battery.

  Next, a battery module according to a second embodiment of the invention will be described. As shown in FIGS. 5 and 6, according to the second embodiment, the casing 14 of the battery module 10 discharges the cooling air flowing into the casing from the bottom wall side from the both side walls of the casing. It is configured. That is, the casing 14 is formed in the elongated slit-like inlet 30a formed along the bottom edge of the cover plate 26 and the bottom wall 24d of the main body 24 and extends along the bottom edge of the main wall 24a. It has a slit-shaped inlet 30b. These inflow ports 30a and 30b communicate with the circulation spaces 28a and 28b defined in the housing 14, respectively. Each of the inflow ports 30a and 30b may be formed so that the width gradually increases from the inside of the housing 14 toward the outside.

  The casing 14 is formed in two elongated slit-shaped outlets 32a formed along both side edges of the cover plate 26 and both side walls 24b of the main body 24, and extends along both side edges of the main wall 24a. Two elongated slit-shaped outlets 32b are provided. These outlets 32a and 32b communicate with the circulation spaces 28a and 28b, respectively. Each of the outflow ports 32a and 32b may be formed so that the width gradually increases from the inside of the housing 14 toward the outside.

Further, the inner surface of the cover plate 26 and the inner surface of the main wall 24a of the main body 24 are curved as a guide for guiding the cooling air flowing into the circulation spaces 28a and 28b from the inflow ports 30a and 30b to the outflow ports 32a and 32b. Guide ribs 40 are integrally formed.
In the second embodiment, the other configuration of the battery module 10 is the same as that of the first embodiment described above, and the same reference numerals are given to the same portions, and detailed description thereof is omitted.

  According to the battery module 10 according to the second embodiment, the cooling air flowing in from the inlets 30a and 30b formed on the bottom wall side of the casing 14 flows around the secondary battery 12, and then the casing Are discharged out of the housing from the outlets 32a and 32b formed on both side walls. Therefore, the secondary battery can be sufficiently cooled by the cooling air. Moreover, the area of the outflow ports 32a and 32b can be increased, the flow resistance can be reduced, the flow rate can be increased, and the cooling performance of the secondary battery can be improved. At the same time, by providing guide ribs for guiding the cooling air, the flow resistance of the cooling air can be further reduced, and the cooling performance of the secondary battery can be further improved. In addition, also in 2nd Embodiment, the effect similar to 1st Embodiment can be acquired.

  In the second embodiment described above, the circulation space in which the cooling medium can be circulated is not limited to the both surfaces of the secondary battery, but is provided at least between one main wall of the housing and the secondary battery. As a result, the cooling performance of the secondary battery can be improved.

Next, a battery pack according to a third embodiment of the invention will be described.
As shown in FIGS. 7 and 8, the battery pack 50 includes a plurality of battery modules 10 and is configured by stacking these battery modules. Each battery module 10 includes a secondary battery 12 and a frame-shaped casing 14 that covers the outer peripheral surface of the secondary battery except for both main surfaces of the secondary battery of the secondary battery.

  The secondary battery 12 includes a flat rectangular box-shaped case 16 made of aluminum or the like, an electrode body 18 housed in the case together with a nonaqueous electrolyte solution, one end wall of the case 16, here a ceiling It has a positive terminal 20a and a negative terminal 20b protruding from the wall. The electrode body 18 is formed in, for example, a flat rectangular shape in which a positive electrode plate and a negative electrode plate are wound in a spiral shape with a separator interposed therebetween, and further compressed in the radial direction. The positive electrode terminal 20 a and the negative electrode terminal 20 b are connected to the positive electrode and the negative electrode of the electrode body 18, respectively, and extend through the top wall of the case 16 in a liquid-tight manner. A gasket made of an insulator (not shown) is provided between the positive terminal 20a and the negative terminal 20b and the top wall of the case.

  The casing 14 is formed in a rectangular frame shape slightly larger than the secondary battery 12, and is formed of an insulating material, for example, a synthetic resin such as ABS resin or polycarbonate. The housing 14 has a pair of side walls 24b, a top wall 24c, and a bottom wall 24d. A pair of openings for exposing the positive terminal 20a and the negative terminal 20b of the secondary battery 12 are formed in the top wall 24c.

  The secondary battery 12 is housed in the housing 14, and both side walls, the top wall, and the bottom wall of the case 16 are covered with the housing 14. The main surfaces before and after the case 16 are exposed. The positive electrode terminal 20a and the negative electrode terminal 20b of the secondary battery 12 are positioned in a pair of openings formed in the top wall 24c of the housing 14, and project outward from the top wall 24c of the housing through these openings.

  The plurality of battery modules 10 are aligned and stacked with the side edges of the housing 14 in contact with each other. Adjacent casings 14 are connected to each other by a fitting protrusion (not shown) or a connecting member to constitute an outer case 52 of the battery pack 50. Adjacent battery modules 10 are stacked with an insulating plate 42 interposed between the main surfaces of the case 16 of the secondary battery 12. Each insulating plate 42 is formed in a rectangular shape slightly smaller than the main surface of the case 16 by an insulating material such as synthetic resin. The insulating plate 42 is in contact with the main surface of the adjacent case 16 and insulates the adjacent secondary batteries 12 from each other.

  According to the battery pack 50 configured as described above, when forming a battery pack by stacking a plurality of battery modules, the outer casing 14 can be formed by connecting the casings 14 to each other. And simplification of the configuration. In addition, the casing 14 is formed in a frame shape that exposes the main surface of the secondary battery, and the insulating plate is sandwiched between the cases of the adjacent secondary batteries, so that the dimensions in the stacking direction of the battery pack 50 can be reduced. This can reduce the size of the battery pack.

  The present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. Some constituent elements may be deleted from all the constituent elements shown in the embodiments, or constituent elements over different embodiments may be appropriately combined.

  For example, the shape, size, material, and the like of the secondary battery and the housing are not limited to the above-described embodiments, and can be changed as appropriate. The number and shape of the inlet and outlet of the housing can be changed as necessary.

FIG. 1 is a perspective view showing a battery module according to the first embodiment. FIG. 2 is an exploded perspective view showing the battery module. FIG. 3 is a cross-sectional view of the battery module taken along line AA in FIG. 1. FIG. 4 is a cross-sectional view of the battery module taken along line BB in FIG. FIG. 5 is a perspective view showing a battery module according to a second embodiment. FIG. 6 is a perspective view showing the bottom wall side of the battery module according to the second embodiment. FIG. 7 is a perspective view showing a battery pack according to a third embodiment. 6 is a cross-sectional view of the battery pack taken along line CC in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Battery module, 12 ... Secondary battery, 14 ... Case, 16 ... Case,
18 ... Electrode body, 20a ... Positive electrode terminal, 20b ... Negative electrode terminal, 24 ... Main body,
26 ... Cover plate, 28a, 28b ... Distribution space, 30a, 30b ... Inlet,
32a, 32b ... outlet, 40 ... guide rib, 42 ... insulating plate,
50 ... Battery pack

Claims (5)

A secondary battery having a case, an electrode body housed in the case, and a terminal connected to the electrode body and protruding from the case;
A housing having insulation and covering the outer surface of the secondary battery,
A circulation space capable of circulating a cooling medium is formed between the case of the secondary battery and the inner surface of the casing , and the casing circulates through the inlet that guides the cooling medium to the circulation space and the circulation space. A battery module, wherein the inlet and the outlet are formed so as to gradually increase in size from the inside of the housing toward the outside . The case of the secondary battery and the casing are each formed in a rectangular box shape,
The housing includes a pair of main walls facing the main surface of the case, a pair of side walls facing each other, a bottom wall, and a top wall from which the terminals of the secondary battery are exposed,
The battery module according to claim 1, wherein the circulation space is formed between the at least one main wall and the secondary battery.   The battery module according to claim 2, wherein the inflow port is formed on one side wall of the housing, and the outflow port is formed on the other side wall of the housing.   The battery module according to claim 2, wherein the inflow port is formed in a bottom wall of the housing, and the outflow port is formed in each side wall of the housing. 5. The guide rib according to claim 1, further comprising a guide rib that is provided on an inner surface of the housing in the circulation space and guides the cooling medium that has flowed into the circulation space from the inlet to the outlet. Battery module.

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