The present disclosure relates to a support structure and, more particularly, to a support member and a storage battery module that house a plurality of storage battery cells.
When a plurality of cylindrical unit batteries are arranged in a trefoil formation such that the batteries are placed in contact with each other, the gap between the outer circumferential surfaces of the unit batteries can be minimized and high energy density of the battery pack can be achieved. However, the unit battery located at the corner of the outer circumferential part of the unit battery group is adjacent to fewer unit batteries than the other unit batteries located elsewhere. When the unit battery located at the corner dissipates heat abnormally, the adjacent unit batteries will also be at an abnormal temperature because the number of paths to transfer heat from that unit battery is relatively small. This is addressed by providing a metal frame that extends along the circumference of the unit battery group to surround the unit battery group and by placing the unit battery located at the corner of the unit battery group, which presents a substantially rectangular shape as viewed from the axial end of the unit batteries, in contact with the metal frame (see, for example, patent literature 1).
It is desired to increase the number of adjacent batteries when a plurality of batteries are arranged in a trefoil formation.
The present disclosure addresses the above-described issue, and a purpose thereof is to provide a technology of increasing the number of adjacent batteries when a plurality of batteries are arranged in a trefoil formation.
A support member according to an embodiment of the present disclosure is a support member for arranging m×n (n is an integer equal to or larger than 4) cylindrical batteries in a trefoil formation structure comprised of m (m is an integer equal to or larger than 4) tiers along a first direction, wherein along a second direction that intersects the first direction, n batteries are arranged in a first tier, n+1 batteries are arranged in a second tier, n batteries are arranged in an m−1th tier, and n−1 batteries are arranged in a m-th tier, the n batteries in the first tier are arranged inward of the n+1 batteries in the second tier in the second direction, and the n−1 batteries in the m-th tier are arranged inward of the n batteries in the m−1th tier in the second direction.
Another embodiment of the present disclosure relates to a storage battery module. The battery module includes: a plurality of storage battery cells; an inner case that houses the plurality of storage battery cells; and an outer case that houses the inner case. Each of the plurality of storage battery cells has a cylindrical shape. The inner case includes a support member for arranging m×n (n is an integer equal to or larger than 4) storage battery cells in a trefoil formation structure comprised of m (m is an integer equal to or larger than 4) tiers along a first direction. In the support member, along a second direction that intersects the first direction, n storage battery cells are arranged in a first tier, n+1 storage battery cells are arranged in a second tier, n storage battery cells are arranged in an m−1th tier, and n−1 storage battery cells are arranged in a m-th tier, the n storage battery cells in the first tier are arranged inward of the n+1 storage battery cells in the second tier in the second direction, and the n−1 storage battery cells in the m-th tier are arranged inward of the n storage battery cells in the m−1th tier in the second direction.
According to the present disclosure, the number of adjacent batteries can be increased when a plurality of batteries are arranged in a trefoil formation.
A summary will be given before describing the embodiment of the present disclosure in specific details. This embodiment relates to a storage battery module in which a plurality of storage battery cells are housed. In the case the storage battery is a lithium ion secondary battery, a gas is generated in the storage battery cell in the event that an internal short-circuit occurs. Generation of the gas increases the pressure in the storage battery cell, but the safety mechanism discharges the gas from the anode side outside the storage battery cell. The gas in this case is at a high temperature and a high pressure so that combustion induced by the gas causes other storage battery cells in the storage battery module to undergo thermal runaway (catch fire). The spread of fire may burn the entirety of the storage battery module or the entire product. To inhibit combustion induced by the gas, it is effective to provide a discharge port in the storage battery module to discharge the gas out of the storage battery module from the discharge port. However, downsizing of a storage battery module reduces a distance between each storage battery cell and the discharge port. As a result, the high-temperature high-pressure gas would be discharged directly from the discharge port, creating a dangerous situation outside.
In the storage battery module according to this embodiment, a plurality of storage battery cells are housed in an inner case, and the inner case is housed in an outer case. An inner discharge port is provided in the inner case, and an outer discharge port is provided in the outer case. Further, a discharge path on which the high-temperature high-pressure gas is circulated is provided between the inner case and the outer case. With such a structure, the high-temperature high-pressure gas emitted from the storage battery cell moves inside the inner case and is discharged out of the inner case from the inner discharge port. The high-temperature high-pressure gas discharged outside the inner case passes through the discharge path and is discharged out of the outer case from the outer discharge port. As a result, the path on which the high-temperature high-pressure gas travels in the storage battery module is extended, and the area of contact between the outer case/inner case and the high-temperature, high-pressure gas is increased. This cools the high-temperature high-pressure gas in the storage battery module.
In such a storage battery module, a plurality of storage battery cells are arranged in a trefoil formation in order to minimize the gap between the outer circumferential surfaces of the storage battery cells. Of the plurality of storage battery cells arranged in the trefoil formation, the storage battery cell located at the corner is adjacent to only two other storage battery cells. When the number of adjacent other storage battery cells is small and when the storage battery cell located at the corner dissipates heat abnormally, the adjacent other storage battery cells will also be at an abnormal temperature because the number of paths to transfer heat from that storage battery cell is relatively small. It is therefore desired to increase, of the plurality of storage battery cells arranged in the trefoil formation, the number of other storage batteries adjacent to the storage battery cell located at the corner. The terms “parallel” and “perpendicular” in the following description not only encompass completely parallel or perpendicular but also encompass off-parallel and off-perpendicular within the margin of error. The term “substantially” means identical within certain limits.
The upper case 400 is connected to the upper side of the outer case 100 and represents the lid part of the outer case 100. An arch-shaped handle 410 projecting upward is provided in the upper case 400. The upper case 400 is made of, for example, resin or metal. The lower case 500 is connected to the lower side of the outer case 100 and represents the bottom part of the outer case 100. The lower case 500 has a shape projecting further downward from the outer case 100. The lower case 500 is made of, for example, resin.
The front case side surface 244 and the rear case side surface 254 are connected such that the rear end of the front case side surface 244 and the front end of the rear case side surface 254 are in contact. As a result, the front case side surface 244 and the rear case side surface 254 form a single surface, and the surface is referred to as a second surface 272. In association with the second surface 272, the front case front surface 242 is referred to as a first surface 270, and the rear case rear surface 252 is referred to as a third surface 274. The first surface 270 faces the first outer plate 110a of the outer case 100. The second surface 272 faces the second outer plate 110b of the outer case 100 and is adjacent to the first surface 270. Further, the third surface 274 faces the third outer plate 110c of the outer case 100, is adjacent to the second surface 272, and faces a direction opposite to the first surface 270. In other words, the combination of the front case 240 and the rear case 250 has three rectangular surfaces. The front case 240 and the rear case 250 are made of, for example, metal. The detail of the structure in the front case 240 and the rear case 250 will be described in detail later.
As described above, the battery holder 230 has a box shape elongated in the vertical direction and houses the storage battery assembly 200. Each storage battery assembly 200 includes a plurality of storage battery cells 210. The storage battery cell 210 is, for example, a lithium ion secondary battery having a columnar or cylindrical shape. An anode 212 and a cathode 214 facing opposite directions are provided at the ends of columnar shape of the storage battery cell 210. A publicly known technology may be used for the storage battery cell 210. A safety mechanism for discharging a high-temperature high-pressure gas outside when the internal pressure rises due to the occurrence of internal short-circuit, etc. Generally, the high-temperature high-pressure gas is discharged from the anode 212. Some of the plurality of storage battery cells 210 are provided such that the anode 212 faces frontward, and the rest of the plurality of of storage battery cells 210 are provided such that the cathode 214 faces frontward. The former represents arranging the anode 212 to face the first surface 270, and the latter represents arranging the cathode 214 to face the first surface 270. For example, the number of storage battery cells 210 arranged in the former manner and the number of storage battery cells 210 arranged in the latter manner are identical.
The front surface and a portion of the right surface of the battery holder 230 are covered by the front case 240, and the rear surface and the remaining portion of the right surface of the battery holder 230 are covered by the rear case 250. The combination of the battery holder 230, the front case 240, and the rear case 250 is an inner case 220, and the inner case 220 houses a plurality of storage battery cells 210 inside.
A left side wall 280 extending in the vertical direction is provided at the left edge of the first surface 270 of the front case 240. The left side wall 280 projects frontward to be in contact with the first outer plate 110a of the outer case 100. A right side wall 282 extending in the vertical direction is provided at the right edge of the first surface 270 of the front case 240. The right side wall 282 also projects frontward to be in contact with the first outer plate 110a of the outer case 100. The left side wall 280 extends across substantially the entirety of the first surface 270 in the vertical direction, but the right side wall 282 extends in a length shorter than the left side wall 280, and a passage groove 284 is provided above the right side wall 282. The passage groove 284 connects the first surface 270 and the second surface 272 continuously. A first inner discharge port 260a extending in the horizontal direction is provided on the lower side of the area of the first surface 270 sandwiched by the left side wall 280 and the right side wall 282. The first inner discharge port 260a extends through the first surface 270.
Meanwhile, the third surface 274 of the rear case 250 has a structure similar to that of the first surface 270. Therefore, like the passage groove 284 in the first surface 270, a passage groove 294 is provided in the third surface 274. The passage groove 294 connects the third surface 274 and the second surface 272 continuously. In association with the first inner discharge port 260a in the first surface 270, a second inner discharge port 260b extending in the horizontal direction is provided in the lower part of the third surface 274. The second inner discharge port 260b extends through the third surface 274.
Further, as also shown in
In the case any of the storage battery cells 210 undergoes thermal runaway in the storage battery module 1000 having the above-described structure, the storage battery cell 210 emits a high-temperature high-pressure gas from the anode 212. The high-temperature high-pressure gas is guided to the first inner discharge port 260a or the second inner discharge port 260b as it comes into contact with the first surface 270 or the third surface 274. The high-temperature high-pressure gas is discharged from the first inner discharge port 260a to the space between the first surface 270 and the first outer plate 110a and is guided to the passage groove 284 as it comes into contact with the first surface 270 and the first outer plate 110a. Alternatively, the high-temperature high-pressure gas is discharged from the second inner discharge port 260b to the space between the third surface 274 and the third outer plate 110c and is guided to the passage groove 284 as it comes into contact with the third surface 274 and the third outer plate 110c.
The high-temperature high-pressure gas moves from the passage groove 284 or the passage groove 294 to the second surface 272. The high-temperature high-pressure gas travels to the intermediate discharge port 264 as it comes into contact with the second surface 272 and the second outer plate 110b. The high-temperature high-pressure gas is discharged from the intermediate discharge port 264 to the extended space 510. The extended space 510 is a space wider than the preceding paths. As the high-temperature high-pressure gas enters the extended space 510, the pressure of the high-temperature high-pressure gas is reduced, and the temperature of the high-temperature high-pressure gas is reduced. Further, an outer discharge port (not shown) connected to the extended space 510 is provided in the lower part of the lower case 500. The outer discharge port extends through the lower case 500. The high-temperature high-pressure gas in the extended space 510 is discharged outside from the outer discharge port.
To summarize the above, four storage battery cells 210 are arranged in the first tier, five storage battery cells 210 are arranged in the second tier, four storage battery cells 210 are arranged in the third tier, and three storage battery cells 210 are arranged in the fourth tier. Further, the four storage battery cells 210 in the first tier are arranged inward of the five storage battery cells 210 in the second tier in the z-axis direction. Further, the three storage battery cells 210 in the fourth tier are arranged inward of the four storage battery cells 210 in the third tier in the z-axis direction. Each storage battery cell 210 is labeled by the number of adjacent storage battery cells 210. As illustrated, the number of adjacent storage battery cells 210 is “3” or larger.
Meanwhile, when the 25th storage battery cell 210be is moved to the left of the 41st storage battery cell 210da, an ordinary trefoil formation structure comprised of four tires is formed such that four storage battery cells 210 are arranged per one tier. The storage battery cell 210 moved from the 25th storage battery cell 210be is indicated by a dotted line. This storage battery cell 210 is adjacent to “2” storage battery cells 210. Thus, the number of adjacent storage battery cells 210 is increased by turning the ordinary trefoil formation structure into a trefoil formation structure as shown in
To summarize the above, four storage battery cells 210 are arranged in the first tier, five storage battery cells 210 are arranged in the second tier, four storage battery cells 210 are arranged in the third tier and the fourth tier, and three storage battery cells 210 are arranged in the fifth tier. Further, the four storage battery cells 210 in the first tier are arranged inward of the five storage battery cells 210 in the second tier in the z-axis direction. Further, the three storage battery cells 210 in the fifth tier are arranged inward of the four storage battery cells 210 in the fourth tier in the z-axis direction. Each storage battery cell 210 is labeled by the number of adjacent storage battery cells 210. As illustrated, the number of adjacent storage battery cells 210 is “3” or larger in this case, too.
Meanwhile, when the 25th storage battery cell 210be is moved to the left of the 41st storage battery cell 210da and the 44th storage battery cell 210dd is moved to the left of the 51st storage cell 210ea, an ordinary trefoil formation structure comprised of five tires is formed such that four storage battery cells 210 are arranged per one tier. The storage battery cell 210 moved from the 25th storage battery cell 210be and the storage battery cell 210 moved from the 44th storage battery cell 210dd are indicated by dotted lines. These storage battery cells 210 are adjacent to “2” storage battery cells 210. Thus, the number of adjacent storage battery cells 210 is increased by turning the ordinary trefoil formation structure into a trefoil formation structure as shown in
Defining the first direction along the y-axis and the second direction along the z-axis, the structures of FIGS. 3A-3B are generalized as follows. A total of m×n (n is an integer equal to or larger than 4) storage battery cells are arranged in a trefoil formation structure comprised of m (m is an integer equal to larger than 4) tiers. In the first tier, n storage battery cells 210 are arranged in the first tier, n+1 storage battery cells 210 are arranged in the second tier, n storage battery cells 210 are arranged in the m−1th tier, and n−1 storage battery cells 210 are arranged in the m-th tier. The n storage battery cells 210 in the first tier are arranged inward of the n+1 storage battery cells 210 in the second tier in the second direction. The n−1 storage battery cells 210 in the m-th tier are arranged inward of the n storage battery cells 210 in the m−1th tier in the second direction. In the case m is an integer equal to or larger than 5, n storage battery cells 210 are arranged in the third tier through the m−2th tier.
The shape of the outer case 100 is not limited to the illustrated shape. An alternative shape of the outer case 100 will be described below.
Also, a handle component 820 is provided in the through hole 800. The handle component 820 has a shape of a frame including an inner wall of the through hole 800 and a wall of the handle 810 toward the through hole 800. The handle component 820 is made of metal. By providing the handle component 820, the rigidity of the handle 810 is improved. The arrangement of the plurality of storage battery cells 210 presents an upward slope in the positive direction of the y-axis. Therefore, a lower space 840 is formed between the plurality of storage battery cells 210 and the second outer case 100b. A terminal 850 for input and output of power in the plurality of storage battery cells 210 is provided in the lower space 840.
According to the embodiment, the n storage battery cells 210 in the first tier are provided inward of the n+1 storage battery cells 210 in the second tier, and the n−1 storage battery cells 210 in the m-th tier are arranged inward of the n storage battery cells 210 in the m−1th tier so that the number of adjacent storage battery cells 210 can be increased. In the case m is an integer equal to or larger than 5, n storage battery cells 210 are arranged in the third tier through the m−2th tier so that the number of tiers can be increased.
Further, the high-temperature high-pressure gas emitted from the storage battery cell 210 is circulated inside the storage battery module 1000 and discharged from the outer discharge port so that the path on which the high-temperature high-pressure gas travels in the storage battery module 1000 can be extended. Further, the path on which the high-temperature high-pressure gas travels in the storage battery module 1000 can be extended so that the high-temperature high-pressure gas can be cooled. Further, the high-temperature high-pressure gas can be cooled so that the high-temperature high-pressure gas emitted from the storage battery cell 210 undergoing thermal runaway is inhibited from being discharged outside. Further, the path of the high-temperature high-pressure gas is formed on the first surface 270 and on the second surface 272 in the inner case 220 so that the path can be provided efficiently. Further, the path can be provided efficiently so that the size of the storage battery module 1000 can be reduced.
Further, the high-temperature high-pressure gas passes through the extended space 510 provided between the second surface 272 and the outer discharge port so that the pressure of the high-temperature high-pressure gas can be reduced. Further, the pressure of the high-temperature high-pressure gas is reduced so that the high-temperature high-pressure gas can be cooled. Further, the storage battery cell 210 having the anode 212 facing the first surface 270 and the storage battery cell 210 having the anode 212 facing the third surface 274 can be provided. Further, the fourth surface 276 is provided separately from the first surface 270 through the third surface 274 so that the impact from the high-temperature high-pressure gas on the fourth surface 276 can be reduced. Further, the outer case 100 includes the handle 810 provided at one end, in the second direction, of the trefoil formation structure of the storage battery cells 210 comprised of m tiers so that the size of the outer case 100, which includes the handle 810, can be reduced. Further, the R part 830 is included in the handle 810 and so makes it easy to hold the handle 810. Further, the handle 810 includes the handle component 820 so that the rigidity of the handle 810 can be improved. Further, the outer case 100 includes the terminal 850 at one end, in the second direction, of the trefoil formation structure of the storage battery cells 210 comprised of m tiers so that the size of the outer case 100, which includes the terminal 850, can be reduced.
A summary of an embodiment of the present disclosure is given below. A support member according to an embodiment of the present disclosure is for arranging m×n (n is an integer equal to or larger than 4) cylindrical storage battery cells (210) in a trefoil formation structure comprised of m (m is an integer equal to or larger than 4) tiers along a first direction, wherein along a second direction that intersects the first direction, n storage battery cells (210) are arranged in a first tier, n+1 storage battery cells (210) are arranged in a second tier, n storage battery cells (210) are arranged in an m−1th tier, and n−1 storage battery cells (210) are arranged in a m-th tier, the n storage battery cells (210) in the first tier are arranged inward of the n+1 storage battery cells (210) in the second tier in the second direction, and the n−1 storage battery cells (210) in the m-th tier are arranged inward of the n storage battery cells (210) in the m−1th tier in the second direction.
In the case m is an integer equal to or larger than 5 n storage battery cells (210) are arranged in a third through an m−2th tiers.
Another embodiment of the present disclosure relates to a storage battery module (1000). The storage battery module (1000) includes: a plurality of storage battery cells (210); an inner case (220) that houses the plurality of storage battery cells (210); and an outer case (100) that houses the inner case (220). Each of the plurality of storage battery cells (210) has a cylindrical shape, The inner case (220) includes a support member for arranging m×n (n is an integer equal to or larger than 4) storage battery cells (210) in a trefoil formation structure comprised of m (m is an integer equal to or larger than 4) tiers along a first direction. In the support member, along a second direction that intersects the first direction, n storage battery cells (210) are arranged in a first tier, n+1 storage battery cells (210) are arranged in a second tier, n storage battery cells (210) are arranged in an m−1th tier, and n−1 storage battery cells (210) are arranged in a m-th tier, the n storage battery cells (210) in the first tier are arranged inward of the n+1 storage battery cells (210) in the second tier in the second direction, and the n−1 storage battery cells (210) in the m-th tier are arranged inward of the n storage battery cells (210) in the m−1th tier in the second direction.
The outer case (100) may include a handle provided at one end of the trefoil formation structure of the storage battery cells (210) stacked in the m tiers.
Given above is a description of the present disclosure based on an exemplary embodiment. The embodiment is intended to be illustrative only and it will be understood by those skilled in the art that various modifications to constituting elements and processes could be developed and that such modifications are also within the scope of the present disclosure.
In the embodiment, the plurality of storage battery cells 210 are aligned in two directions. Alternatively, the plurality of storage battery cells 210 may be aligned in one direction. According to this variation, the flexibility in the configuration is improved.
In the embodiment, the storage battery cells 210 are used. Alternatively, however, batteries other than the storage battery cells 210 may be used. According to this variation, the flexibility in the configuration is improved.
In the embodiment, the inner case 220 is formed by combining the battery holder 230, the front case 240, and the rear case 250. Alternatively, the inner case 220 may be formed by combining at least one of the front case 240 or the rear case 250, and the battery holder 230. In this case, the configuration including the battery holder 230 represents the support member. According to this variation, the flexibility in the configuration is improved.
According to the present disclosure, the number of adjacent batteries can be increased when a plurality of batteries are arranged in a trefoil formation.
100 outer case, 110 outer plate, 200 storage battery assembly, 210 storage battery cell (battery), 212 anode, 214 cathode, 220 inner case, 230 battery holder (support member), 240 front case, 242 front case front surface, 244 front case side surface, 250 rear case, 252 rear case rear surface, 254 rear case side surface, 260 inner discharge port, 264 intermediate discharge port, 270 first surface, 272 second surface, 274 third surface, 276 fourth surface, 280 left side wall, 284, 294 passage groove, 400 upper case, 410 handle, 500 lower case, 510 extended space, 600 upper packing, 610 lower packing, 700 thermal runaway storage battery cell, 710 adjacent storage battery cell, 1000 storage battery module.
Number | Date | Country | Kind |
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2019-050015 | Mar 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/010414 | 3/11/2020 | WO | 00 |