JP7322719B2 - battery pack - Google Patents

Description

TECHNICAL FIELD The present invention relates to a battery pack having excellent fire spread prevention properties.

In recent years, cordless electronic devices such as mobile phones and personal computers are becoming increasingly cordless, and the use of secondary batteries that are compact, lightweight, and have high energy density is increasing as a power source for driving these devices. Under such circumstances, lithium-ion secondary batteries with large charge/discharge capacities and high energy densities are attracting attention.

JP 2009-301877 A Japanese Patent Publication No. 2012-511802 JP 2010-218716 A

As a lithium-ion secondary battery, a laminated battery pack formed by stacking a plurality of lithium-in secondary battery cells has been devised. However, in a laminated lithium-ion secondary battery, the battery cells may generate heat due to heat generation due to oxidation of the electrolyte, short circuit due to deposition of metallic lithium, etc., and if heat generation occurs, A fire-spread prevention structure is required to prevent fire from spreading to other battery cells.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery pack that is excellent in preventing the spread of fire.

A battery pack according to the present invention includes a battery chamber that internally stores a stacked battery cell in which a plurality of battery cells are stacked, and a gas chamber that communicates with the battery chamber and is a chamber separate from the battery chamber. a gas chamber provided with an opening communicating with the gas chamber, wherein the gas chamber is provided with a shield so as to block a straight path connecting the battery cell and the opening.

According to the present invention, when the cells in the battery chamber generate heat, the path of high-temperature gas ejected from the battery chamber is shielded by the shield, thereby lengthening the path of gas from the battery chamber to the opening. As a result, the temperature of the gas drops as it passes through the longer path, so it is possible to prevent the gas from coming into contact with oxygen in the air and igniting when discharged from the opening. becomes. In addition, since the temperature of the gas is lowered, the backdraft caused by the backflow of the gas is suppressed, and it is possible to suppress ignition and spread of fire in the battery chamber.

In the present invention, it is possible to employ a configuration in which the opening is provided on a surface of the gas chamber other than the surface facing the battery chamber. According to this, the high-temperature gas ejected from the battery chamber does not directly pass through the opening to the outside, but flows outside through the opening after changing direction in the gas chamber. Therefore, since the temperature of the gas drops before it flows out, it is possible to prevent the gas from coming into contact with oxygen in the air at a high temperature and igniting.

In the present invention, it is possible to adopt a configuration in which the surface of the gas chamber facing the battery chamber is provided with a branch portion for changing the direction of the path of the gas released from the battery chamber. According to this, the direction of the hot gas ejected from the battery chamber can be smoothly changed to the lateral direction. Therefore, it is possible to lengthen the path of the gas and lower the temperature of the gas, thereby suppressing ignition in the battery chamber.

According to the present invention, it is possible to employ a configuration in which a heat insulating portion that suppresses heat conduction is provided between the battery chamber and the gas chamber. According to this, it is possible to suppress direct transmission of the heat of the housing of the gas chamber, which has been heated to a high temperature by the heat of the high-temperature gas ejected from the battery chamber, to the housing that constitutes the battery chamber. becomes. As a result, it becomes possible to suppress the increase in temperature of the battery chamber and to suppress the spread of fire to other battery cells.

According to the present invention, it is possible to employ a configuration in which the gas chamber is provided with a plate portion provided at a predetermined distance from the inner wall of the gas chamber. According to this, it is possible to prevent the heat of the high-temperature gas ejected from the battery chamber from being directly transmitted to the housing constituting the gas chamber. As a result, heat transfer to the housing that constitutes the battery chamber is suppressed. As a result, it is possible to suppress an increase in the temperature of the battery chamber, thereby suppressing the spread of fire to other battery cells.

According to the present invention, it is possible to employ a configuration in which the surface of the plate portion is provided with an obstruction portion that obstructs the flow of gas released from the battery chamber. According to this, the gas flow is disturbed by the obstruction provided on the surface of the plate portion, the flow velocity of the gas decreases, and the time required for the gas to flow out from the opening becomes longer. The gas temperature drops. As a result, the battery chamber is prevented from becoming hot, and the gas is prevented from spreading to other battery cells.

According to the present invention, it is possible to employ a configuration in which the board portion is a circuit board and the obstacle portion is an electronic component. According to this, since the circuit board can be used to lower the temperature of the gas by arranging the circuit board in the gas chamber, there is no need to separately provide other members, which contributes to cost reduction.

Thus, according to the present invention, it is possible to provide a battery pack that is excellent in preventing the spread of fire.

FIG. 1 is a perspective view showing a schematic appearance of a battery pack 1A according to a first embodiment of the invention. FIG. 2 is a perspective view showing a schematic configuration of the battery pack 1A with the case 2 removed. FIG. 3 is a perspective view showing an outline of the internal configuration of the battery pack 1A. FIG. 4 is a perspective view showing the outline of the appearance of the battery pack 1B according to the second embodiment of the invention. FIG. 5 is a see-through perspective view showing an outline of the internal configuration of the battery pack 1B. FIG. 6 is an exploded perspective view showing a schematic structure of the battery pack 1B. FIG. 7 is a perspective view showing a schematic appearance of a battery pack 1C according to a third embodiment of the invention. FIG. 8 is a see-through perspective view showing an outline of the internal configuration of the battery pack 1C. FIG. 9 is a cross-sectional view in the xy plane showing the schematic configuration of the gas chamber case 5 and the outline of the gas release path. FIG. 10 is a partially broken perspective view showing the schematic structure of the gas chamber case 5 and the outline of the gas release path. FIG. 11 is a cross-sectional view in the xy plane showing the outline of the appearance of the battery pack 1D according to the fourth embodiment of the present invention.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, members that are the same as those already described are given the same reference numerals or names, and the description thereof will be omitted.

(First embodiment)
A battery pack 1A according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a perspective view showing a schematic appearance of a battery pack 1A according to a first embodiment of the invention. FIG. 2 is a perspective view showing a schematic configuration of the battery pack 1A with the case 2 removed. FIG. 3 is a perspective view showing an outline of the internal configuration of the battery pack 1A.

As shown in FIG. 1, the battery pack 1A has a box-shaped case 2 on the outside. The case 2 is made of metal such as aluminum. Terminal wires 3a and 3b for transmitting and receiving electric power are connected to the battery pack 1A.

As shown in FIG. 2, a housing 10 is housed inside the case 2 . The housing 10 includes a top housing 10a and side housings 10b. A gap is provided between the case 2 and the housing 10 to allow gas to pass therethrough.

A side housing 10b of the housing 10 is provided with a plurality of openings 10c. Gas can be communicated between the inside and outside of the housing 10 by the opening 10c. Although the opening 10c is configured as a round hole in FIG. 2, the shape of the opening 10c is not limited to this. The opening 10c may be configured as a rectangular slit, for example.

A facing surface 10d is arranged in the housing 10 at a position facing the battery cell 14 through the gas passage hole 18a. The opening 10c is arranged in the side housing 10b, which is a surface other than the facing surface 10d, which is the surface facing the battery cell 14. As shown in FIG.

As shown in FIG. 3, the inside of the housing 10 is provided with a battery chamber 12 in which a stack-type battery cell formed by stacking a plurality of battery cells 14 is stored. Adjacent to the battery chamber 12 , there is provided a gas chamber 16 that is spatially continuous with the inside of the battery chamber 12 , allows communication of the gas therein, and is separate from the battery chamber 12 . In FIG. 3, the battery chamber 12 and the gas chamber 16 have an internal hollow box shape.

A heat insulating portion 22 is arranged between the partition plate 18 and the battery chamber 12 . The heat insulating portion 22 is made of a material having a lower thermal conductivity than metal. The heat insulating portion 22 blocks heat transfer between the battery chamber 12 and the gas chamber 16 .

A partition plate 18 is provided between the battery chamber 12 and the gas chamber 16 to spatially separate the two. The partition plate 18 is provided with a gas passage hole 18 a for passing gas between the battery chamber 12 and the gas chamber 16 . In FIG. 3, the gas passage hole 18a is configured as a rectangular opening, but the shape is not limited to this. For example, it may be a round hole.

A shielding portion 20 is provided in the gas chamber 16 at a location facing the opening 10c of the side housing 10b. The shielding part 20 is made of metal such as aluminum. The shielding portion 20 includes a parallel portion 20a parallel to the side housing 10b, an oblique portion 20b continuous with the parallel portion 20a and obliquely arranged from the side housing 10b toward the inside of the gas chamber 16, and an oblique portion 20b. and parallel to the parallel portion 20a and separated from the side housing 10b by a predetermined distance. The shielding portion 20 is arranged so as to shield the linear path between the gas passage hole 18a and the opening portion 10c with a three-dimensional structure formed by the oblique portion 20b and the spaced portion 20c. A gap is formed between the shielding portion 20 and the facing surface 10d.

According to the battery pack 1A described above, when heat is generated in the battery chamber 12, the generated heat gas passes through the gas path A shown in FIG. 3 and flows out to the outside. That is, the gas generated in the battery chamber 12 passes through the gas passage hole 18a, flows into the gas chamber 16, and is redirected by the facing surface 10d facing the gas passage hole 18a. After that, it passes through the gap between the shielding part 20 and the facing surface 10d, is guided between the shielding part 20 and the side housing 10b, and flows out of the housing 10 through the opening 10c. The gas path A is longer than the straight path between the gas passage hole 18a and the opening 10c.

In this way, the high-temperature gas generated in the battery chamber 12 does not flow straight out of the opening 10c from the gas passage hole 18a to the outside, but is shielded by the shielding portion 20, thereby being curved and extending the distance. move along gas path A. Since the distance of the gas path A is increased in this way, the temperature of the high-temperature gas flowing out of the battery chamber 12 while passing through the gas path A decreases. Since the gas whose temperature has been sufficiently lowered flows out from the opening 10c, the oxygen in the outside does not come into contact with the high-temperature gas, so that it is possible to suppress ignition of the gas.

In addition, due to the lengthening of the gas path A, the decrease in the temperature of the gas, and the provision of the shielding portion 20 that shields the straight path between the battery chamber 12 and the opening 10c, the backflow of the gas is prevented. is suppressed, thereby suppressing ignition due to backdraft in the battery chamber 12 . In this manner, even if high-temperature gas flows out due to the heat generated by the battery cells 14 in the battery chamber 12, the spread of fire to other battery cells is suppressed.

A heat insulator 22 is arranged between the battery chamber 12 and the gas chamber 16 . As a result, the housings forming the battery chamber 12 and the gas chamber 16 do not come into direct contact with each other, so that the temperature of the high-temperature gas flowing into the gas chamber 16 can be suppressed from propagating into the battery chamber 12. can. This suppresses the spread of fire to other battery cells in the battery chamber 12 .

The opening 10 c is provided on a surface of the gas chamber 16 other than the facing surface 10 d facing the battery chamber 12 . According to this, the direction of the high-temperature gas ejected from the battery chamber 12 toward the facing surface 10d is changed before heading toward the opening 10c. descend. Therefore, it is possible to suppress ignition, backflow of gas, and backdraft due to contact with oxygen in the air while the temperature is high. This suppresses the spread of fire to other battery cells in the battery chamber 12 .

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. 4, 5 and 6. FIG. FIG. 4 is a perspective view showing the outline of the appearance of the battery pack 1B according to the second embodiment of the invention. FIG. 5 is a see-through perspective view showing an outline of the internal configuration of the battery pack 1B. FIG. 6 is an exploded perspective view showing a schematic structure of the battery pack 1B.

As shown in FIG. 4, the outside of the battery pack 1B is composed of a battery chamber case 4 and a gas chamber case 5. As shown in FIG. The battery chamber case 4 and gas chamber case 5 are made of a metal plate such as aluminum.

As shown in FIG. 5, the interior of the battery chamber case 4 serves as a battery chamber 12 in which a stacked battery cell formed by stacking a plurality of battery cells 14 is stored. Further, the inside of the gas chamber case 5 is spatially continuous with the battery chamber 12 to form a gas chamber 16 with which the gas inside the battery chamber 12 can communicate.

As shown in FIGS. 6A, 6B, and 6C, the battery chamber case 4 is configured to have a box shape by combining an upper housing 12a and a bottom housing 12b. there is As shown in FIG. 6(c), an opening 12c through which the battery chamber 12 communicates with the gas chamber 16 is provided in the x direction of the bottom housing 12b. As shown in FIG. 6B, a partition plate 18 is provided between the battery cell 14 and the gas chamber 16 . The partition plate 18 is provided with a gas passage hole 18a through which the gas generated in the battery chamber 12 can pass. Gas generated in the battery chamber 12 flows into the gas chamber 16 through the gas passage hole 18a and the opening 12c.

As shown in FIGS. 6(d), (e), and (f), the gas chamber case 5 is configured to have a box shape by combining an upper housing 16a and a bottom housing 16b. there is Inside, a plate portion 24 is provided so as to be parallel to an arbitrary surface of the upper housing 16a and spaced apart by a predetermined distance. Here, it is arranged so as to be parallel to the plane positioned above the gas chamber 16 . An obstacle portion 24 a is provided on the plate portion 24 . The obstacle 24a is, for example, an electronic component. The obstruction portion 24 a exerts an effect of disturbing the flow of gas that has flowed into the gas chamber 16 .

According to the battery pack 1B according to the second embodiment described above, the gas chamber 16 is provided with the plate portion 24 provided at a predetermined distance from the inner wall of the gas chamber 16 . According to this, the heat of the high-temperature gas ejected from the battery chamber 12 does not directly hit the gas chamber case 5, which is the housing constituting the gas chamber 16, so that the high-temperature heat is transferred to the gas chamber case 5. can be suppressed. This makes it possible to suppress heat transfer from the gas chamber case 5 to the battery chamber case 4 , which is a housing that constitutes the battery chamber 12 . As a result, it becomes possible to suppress the increase in temperature of the battery chamber 12 and to suppress the spread of fire to the other battery cells 14 .

Further, the surface of the plate portion 24 is provided with an obstruction portion 24a that disturbs the flow of the gas released from the battery chamber 12 . According to this, the obstruction portion 24a provided on the surface of the plate portion 24 reduces the flow velocity of the gas. As a result, the time required for the high-temperature gas to flow out of the battery pack 1B from the gas passage hole 18a becomes longer, and the temperature of the gas drops during that time. This suppresses the spread of fire to other battery cells 14 .

Further, in this embodiment, the plate portion 24 is a circuit board, and the obstacle portion 24a is an electronic component provided on the circuit board. According to this, since the circuit board can be used to lower the temperature of the gas by arranging it in the gas chamber 16, there is no need to separately provide other members, which contributes to cost reduction.

(Third embodiment)
A battery pack 1C according to the third embodiment will be described with reference to FIGS. 7 to 10. FIG.

FIG. 7 is a perspective view showing a schematic appearance of a battery pack 1C according to a third embodiment of the invention. FIG. 8 is a see-through perspective view showing an outline of the internal configuration of the battery pack 1C. FIG. 9 is a cross-sectional view showing the schematic configuration of the gas chamber case 5 and the outline of the gas release path. FIG. 10 is a partially broken perspective view showing the schematic structure of the gas chamber case 5 and the outline of the gas release path.

As shown in FIG. 7, the battery pack 1C includes a battery chamber case 4 and a gas chamber case 5. As shown in FIG. The battery chamber case 4 is provided with a connector portion 6 to which a power line or the like is connected. The gas chamber case 5 has a facing surface 5a positioned in the y direction and forming the xz plane, and a side portion 5b positioned in the x direction and forming the yz plane. is provided. Gas can be communicated between the inside and outside of the gas chamber case 5 by the opening 5c. Although the opening 5c is configured as a round hole in FIG. 7, the shape of the opening 5c is not limited to this. The opening 5c may be configured as a slit hole having a predetermined width and length, for example.

A heat insulating portion 22 is provided between the battery chamber case 4 and the gas chamber case 5 .

As shown in FIG. 8, the interior of the battery chamber case 4 serves as a battery chamber 12 in which a stacked battery cell formed by stacking a plurality of battery cells 14 is stored. A gas chamber 16 is formed in a gas chamber case 5 which is adjacent to the battery chamber 12 and which is spatially continuous with the inside of the battery chamber 12 so that the internal gas can communicate therewith. In FIGS. 7 and 8, the battery chamber 12 and the gas chamber 16 have an internal hollow box shape.

As shown in FIGS. 8, 9, and 10, the gas chamber 16 is provided with a shielding portion 26 projecting into the gas chamber 16 from the battery chamber 12. As shown in FIG. The shielding portion 26 has a cylindrical shape with an open top, and communicates the battery chamber 12 and the gas chamber 16 with each other. The shielding portion 26 also functions as an air guide portion to guide the gas flowing out of the battery cell 14 from the battery chamber 12 into the gas chamber 16 . The shielding part 26 is made of metal such as aluminum. The side end of the shielding portion 26 facing the battery chamber 12 is located on the boundary line with the battery chamber 12 and has a substantially square opening 26a. The end of the shielding portion 26 on the side of the gas chamber 16 extends into the gas chamber 16 to form a circular opening 26b. A branching portion 30 having a triangular xy cross section is provided at a position facing the shielding portion 26 on the inner surface of the facing surface 5a. One vertex of the triangle forming the branch portion 30 is directed toward the shield portion 26 . A corner portion 32 having an obtuse angle is formed at the end portion in the x direction of the opposing surface 5a of the gas chamber case 5 .

In the battery chamber 12 of the battery pack 1C configured in this way, when high temperature gas flows out due to heat generation of the battery cells 14, the high temperature gas flows from the battery chamber 12 into the gas chamber 16 through the shielding portion 26. influx. The shielding portion 26 functions as a shielding portion that shields a linear path between the end of the battery cell 14 on the side of the gas chamber 16 and the opening 5c. The gas path A of the gas flowing into the gas chamber 16 is divided into +x direction and -x direction by the branching portion 30 provided on the facing surface 5a. The direction of flow of the gas is changed by the opposing surface 5a and the corner portion 32, and the gas, whose traveling direction is divided by the branch portion 30, is guided to the opening portion 5c and flows out of the battery pack 1C.

The battery pack 1C according to the third embodiment has the same effects as the battery pack 1C according to the first embodiment. According to the battery pack 1C according to the third embodiment, the gas path A of the gas is branched by the branching portion 30 provided on the facing surface 5a facing the shielding portion 26, and the gas path A is smoothed by the corner portion 32. is led to the opening 5c. As a result, it is possible to form the gas path A that advances from the battery chamber 12 in the y direction, is bent by the branch portion 30, and is guided to the opening portion 5c. The gas flow path A is longer than the linear path that linearly connects the battery chamber 12 and the opening 5c.

(Fourth embodiment)
Next, a battery pack 1D according to a fourth embodiment will be described with reference to FIG.

FIG. 11 is a cross-sectional view in the xy plane showing the outline of the appearance of the battery pack 1D according to the fourth embodiment of the present invention. As shown in FIG. 11, the battery pack 1D includes a battery chamber case 4 and a gas chamber case 5. As shown in FIG. The battery chamber case 4 constitutes a battery chamber 12 in which a stacked battery cell formed by stacking a plurality of battery cells 14 is stored. The gas chamber case 5 constitutes a gas chamber 16 into which gas flows from the battery chamber 12 .

The battery chamber case 4 has an opening 4 a that allows communication with the inside of the gas chamber case 5 . The gas chamber case 5 has an opening 5d that allows communication with the inside of the battery chamber case 4. As shown in FIG. The battery chamber case 4 and the gas chamber case 5 are in contact with each other through the heat insulation portion 22 at the contact portion between the opening portion 4a and the opening portion 5d. The inside communicates through 5d.

A wall surface of the gas chamber case 5 facing the battery cell 14 is provided with a facing surface 5a, and an opening 5c is formed in the facing surface 5a. The gas chamber 16 communicates with the outside through the opening 5c.

The gas chamber 16 is provided with a shielding portion 34 that shields a linear path between the opening 5d on the side of the battery chamber 12 and the opening 5c formed in the facing surface 5a. The shielding part 34 is made of metal such as aluminum. The shielding portion 34 has a convex portion 34a that curves so as to protrude toward the facing surface 5a, and a bent portion 34b that bends toward the facing surface 5a at the end in the x direction. The shielding part 34 is separated from the inner wall of the gas chamber case 5 and has a gap through which gas can pass.

The gas that has flowed from the battery chamber 12 into the gas chamber 16 is shielded by the shielding portion 34 as shown by the gas flow path A in FIG. It flows into the opposing surface 5a side and flows out from the opening 5c. The gas flow path A has a longer distance than the linear path that linearly connects the battery chamber 12 and the opening 5c.

The battery pack 1D according to the fourth embodiment has the same effects as the battery pack 1D according to the first embodiment. According to the battery pack 1D according to the fourth embodiment, since the opening 5c can be arranged in the facing surface 5a arranged at the position facing the battery chamber 12, the degree of freedom of the arrangement location of the opening 5c is increases.

In the multiple embodiments described above, the case 2, the battery chamber case 4, the gas chamber case 5, the housing 10, the upper housing 12a, the bottom housing 12b, the top housing 16a, and the bottom housing 16b are made of metal. Although aluminum is exemplified as the material, it is not limited to this. These may be made of a metal other than aluminum, or may be made of a material other than metal, such as engineering plastics having high heat resistance. Similarly, the shielding portion 20, the shielding portion 26, and the shielding portion 34 are not limited to metal, and can be made of other materials having high heat resistance.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Needless to say, it is included within the scope.

1A to 1D Battery pack 2 Case 3a Terminal wire 3b Terminal wire 4 Battery chamber cases 4a, 5c, 5d, 10c, 12c, 16c Opening 5 Gas chamber case 5a Opposing surface 5b Side 6 Connector 10 Housing 10a Top housing 10b side casing 12 battery chamber 12a upper casing 12b bottom casing 14 battery cell 16 gas chamber 16a upper casing 16b bottom casing 18 partition plate 18a gas passage holes 20, 26, 34 shielding portion 22 heat insulating portion 24 plate Part 24a Obstruction part 30 Branch part 32 Corner part 34a Convex part 34b Folded part A Gas path

Claims (5)

a battery chamber having a box-like shape and containing therein a stacked battery cell in which a plurality of battery cells are stacked;
a gas chamber having a box shape and formed of a housing separate from the battery chamber;
a heat insulating part provided between the battery chamber and the gas chamber so that the casing constituting the battery chamber and the casing constituting the gas chamber do not come into direct contact with each other;
The housing constituting the battery chamber is provided with a first opening,
The housing constituting the gas chamber is provided with second, third and fourth openings,
the battery chamber and the gas chamber communicate with each other through the first opening and the second opening;
The gas chamber is provided with a shielding part so as to block a straight path connecting the second opening and the third and fourth openings ,
Gas paths for the gas that has flowed into the gas chamber from the battery chamber through the first and second openings are divided into a first gas path proceeding in a first direction and a gas path opposite to the first direction. divided into a second gas path traveling in a second direction of
The gas passing through the first gas path flows out from the third opening, and the gas passing through the second gas path flows out from the fourth opening. battery pack. 2. The apparatus according to claim 1, wherein the third and fourth openings are provided on a surface of the gas chamber other than the surface facing the surface on which the second opening is provided. battery pack. A gas path for gas discharged from the battery chamber is divided into the first gas path and the second gas path on the surface of the gas chamber facing the surface on which the second opening is provided. 3. The battery pack according to claim 1, wherein a branch is provided. 4. The battery pack according to claim 3, wherein said third and fourth openings are provided on different surfaces of said gas chamber. 2. The battery pack according to claim 1, wherein said third and fourth openings are provided on the same side of said gas chamber.

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