Battery module

Abstract

To provide a battery module which efficiently performs cooling without reducing an energy density.SOLUTION: In a battery pack 12, a battery module comprises: a plurality of cylindrical power storage bodies 14; a case in which the cylindrical power storage bodies are stored; a cathode-side bus bar 16 provided in a lid part 10b of the case and electrically connected to cathodes 14 of all the cylindrical power storage bodies; and an anode-side bus bar 18 provided in a bottom part 10c of the case and electrically connected to anodes 14b of all the cylindrical power storage bodies. The cylindrical power storage body is disposed while keeping an interval, in which a fluid for cooling flows, with the adjacent cylindrical power storage body. Each of the cylindrical power storage bodies is held between the cathode-side bus bar and the anode-side bus bar by rotatably mounting each cylindrical power storage body to the cathode-side bus bar and the anode-side bus bar via a conductive bearing 28. The case includes a fluid inflow port through which the fluid for cooling flows from a direction orthogonal to an axial direction of the cylindrical power storage body with respect to the cylindrical power storage body.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a battery module, and more particularly to a battery module configured such that a plurality of cylindrical power storage units are held in a case in an electrically connected state. [Background technology]

[0002] A battery module, which is configured by holding multiple cylindrical power storage units in an electrically connected state in a case, is densely arranged in a limited space in order to increase the energy density per unit volume. In particular, when used for vehicle applications such as electric vehicles and hybrid vehicles, it is required to make the installation area of ​​the battery module as small as possible within the limited space.

[0003] However, in a situation where cylindrical accumulators are densely arranged in a limited space, problems occur when cooling the battery module. For example, when cooling with a fluid such as air, the cylindrical accumulator arranged in the center of the battery module is blocked by the surrounding cylindrical accumulators, making it difficult for the fluid to pass through, and sufficient cooling effect cannot be obtained. Therefore, there is a risk of a temperature difference between the cylindrical accumulator arranged in a position where the fluid of the battery module is likely to hit and the cylindrical accumulator arranged in the center where the fluid is unlikely to hit. In this situation, the temperature difference causes variations in the electrical characteristics of each cylindrical accumulator, which causes performance deterioration of the battery module, and if a sufficient cooling effect is not obtained, there is a possibility that it may affect safety, such as the risk of thermal destruction of the cylindrical accumulator.

[0004] In the power supply device disclosed in Patent Document 1, the inside of the case is filled with a cooling liquid, and a number of cylindrical power storage bodies are immersed in the cooling liquid. Rotating members are provided in a rotatable state so as to surround each of the cylindrical power storage bodies. By rotating these rotating members, the cooling liquid around the cylindrical power storage bodies is agitated, and the temperature variation of the cooling liquid is suppressed.

[0005] In the battery pack device disclosed in Patent Document 2, multiple batteries are housed horizontally in a housing, a first cooling air inlet and a second cooling air inlet are formed in a pair of side panels of the housing, and a first rectifying fin and a second rectifying fin are arranged in the first cooling air inlet and the second cooling air inlet, respectively, so that the direction of the cooling air flow can be adjusted. The cooling air is blown onto the horizontally placed batteries from a direction perpendicular to the axial direction of the batteries. This configuration makes it possible for the cooling air to flow toward batteries whose temperatures have risen. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-192379 A [Patent Document 2] JP 2010-225472 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the power supply device of Patent Document 1, a rotating member is provided surrounding each cylindrical power storage body, and these rotating members rotate in conjunction with each other, and the rotation direction of adjacent rotating members is controlled to be opposite. As a result, the cooling liquid that cools the cylindrical power storage body is stirred so as to reduce the temperature variation. However, the configuration for operating all the rotating members is complicated, and providing a rotating member for each cylindrical power storage body goes against the trend of increasing the energy density per unit volume.

[0008] The battery pack device in Patent Document 2 is configured to target high-temperature batteries with cooling air to cool them down, but if there are other batteries in front of the battery being cooled, the cooling efficiency is not good. In other words, the cooling air is blocked by the other batteries and does not reach the target battery sufficiently, resulting in insufficient cooling.

[0009] The present invention has been made in consideration of the above problems, and its object is to provide a battery module that can efficiently and evenly cool all cylindrical storage batteries without reducing the energy density per unit area. [Means for solving the problem]

[0010] In order to achieve the above object, a battery module according to one embodiment of the present invention comprises: A battery module comprising: a plurality of cylindrical power storage bodies; and a case in which the cylindrical power storage bodies are housed; the cylindrical power storage bodies are held in the case by a positive bus bar that is provided in the case and electrically connected to positive electrodes of all of the housed cylindrical power storage bodies; and a negative bus bar that is provided in the case and electrically connected to negative electrodes of all of the housed cylindrical power storage bodies; and the cylindrical power storage bodies are charged and power is supplied from the cylindrical power storage bodies to a load via the positive bus bar and the negative bus bar, The cylindrical accumulators are arranged with a gap between adjacent cylindrical accumulators to allow a cooling fluid to flow, and each cylindrical accumulator is held by the positive side bus bar and the negative side bus bar in such a way that the cylindrical accumulator is rotatably attached to the positive side bus bar and the negative side bus bar via a conductive rotating member, and the case is provided with a fluid inlet for allowing the cooling fluid to flow into the cylindrical accumulator from a direction perpendicular to the axial direction of the cylindrical accumulator.

[0011] According to this configuration, the cylindrical power storage units are arranged in the case at intervals so that the cooling fluid can flow, and are cooled by the fluid that flows in through the fluid inlet and perpendicular to the cylindrical axis of the cylindrical power storage unit. When the fluid hits the cylindrical power storage unit, the cylindrical power storage unit rotates due to the flow force of the fluid, since the cylindrical power storage unit is rotatably mounted by the rotating member. This effectively cools the entire circumferential surface, and even if a portion of the cylindrical power storage unit heats up, the fluid hits the heated portion evenly. Furthermore, the rotation of the cylindrical power storage unit also dissipates heat to the surroundings, so that all the cylindrical power storage units can be cooled efficiently and evenly. Effect of the Invention

[0012] According to the battery module of the present invention, a plurality of cylindrical power storage bodies are housed in a case in a rotatable state while being electrically connected to a positive bus bar and a negative bus bar. As a result, the cylindrical power storage bodies are cooled while rotating by being exposed to a cooling fluid. Therefore, the cylindrical power storage bodies are evenly exposed to the fluid and heat is dissipated by the rotation, so that the cylindrical power storage bodies can be cooled efficiently and evenly. This suppresses deterioration of the battery module and allows the battery module to be maintained in a high-performance state. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic block diagram of a battery pack having a battery module according to an embodiment of the present invention; [Diagram 2] This is a top view of the battery module shown in Figure 1. However, the structure above the positive electrode of the cylindrical storage battery is omitted. [Diagram 3] FIG. 2 shows a side view of the battery module shown in FIG. [Figure 4] 2 is an explanatory diagram of the connection between the bus bars and the cylindrical power storage body in the battery module shown in FIG. 1. FIG. [Diagram 5]2 is an explanatory diagram showing an example of control of a cooling fluid in the battery module shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of a battery module of the present invention will be described in detail with reference to the drawings. In this embodiment, the fluid for cooling the cylindrical power storage body is, for example, cooling air generated by a cooling fan.

[0015] 1 shows a schematic block diagram of a battery pack 12 having a battery module 10 according to the present invention, and as shown in the figure, the battery module 10 is housed in a housing of the battery pack 12 together with a cooling fan 26 for cooling the cylindrical power storage body 14 and a connector 26 that enables charging of the battery module 10 and supply of power from the battery module 10 to a load. The battery pack 12 has a housing 12a, which has a lid 12b and a bottom 12c. This allows the battery pack 12 to be kept in a somewhat sealed state and installed in a predetermined location on the vehicle body.

[0016] The battery module 10 includes a positive bus bar 16 connected to the positive electrodes of all of the cylindrical storage batteries 14, and a negative bus bar 18 connected to the negative electrodes of all of the cylindrical storage batteries 14, and the positive bus bar 16 and the negative bus bar 18 are connected to a connector 26.

[0017] The cooling air from the cooling fan 24, which is a fluid inflow mechanism, enters the battery module 10 through a fluid inlet 20 formed in the case 10a of the battery module 10, cools the cylindrical storage battery 14, and is discharged from a fluid outlet 22 formed in the case 10a of the battery module 10.

[0018] Fig. 2 is a top view of the battery module 10 shown in Fig. 1, and Fig. 3 is a side view of the battery module 10 shown in Fig. 1. As shown in the figures, a plurality of cylindrical power storage bodies 14 are arranged upright with the positive electrode side facing up in the case 10a of the battery module 10. The cylindrical power storage bodies 14 are also arranged at intervals that allow a cooling fluid to flow. Furthermore, the cylindrical power storage bodies 14 are arranged in rows with a predetermined gap between adjacent cylindrical power storage bodies 14, and in each row, the cylindrical power storage bodies 14 are arranged in a zigzag pattern in the extension direction of the row.

[0019] A plurality of fluid inlets 20 and fluid outlets 22 are formed in the case 10a of the battery module 10. The cooling air introduced from the fluid inlets 22 is generated by a cooling fan 24 in the battery pack 12, passes through a filter 34, and is guided to the fluid inlets 22 by a duct 32.

[0020] The cooling air is applied to the cylindrical power storage bodies 14 from a direction perpendicular to the axial direction of the cylindrical power storage bodies 14. In this embodiment, as shown in the figure, fluid inlets 20 and fluid outlets 22 are alternately formed on a pair of side walls of the case 10a of the battery module 10. The cooling air from the fluid inlet 20 formed on one side wall flows between the rows of the cylindrical power storage bodies 14 and exits from the fluid outlet 22 formed on the other opposing side wall. The cooling air flowing through the space between the rows, i.e., the fluid flow path 30, flows in the opposite direction in adjacent fluid flow paths 30 because the fluid inlets 20 and fluid outlets 22 are alternately formed on the side walls.

[0021] 2, one duct 32 is provided on each pair of side walls of the case 10a of the battery module 10, but this is merely an example and the number of ducts may be increased as necessary. The capacity of the cooling fan 24 is determined appropriately according to the size of the battery module 10.

[0022] The positive electrode 14a and the negative electrode 14b of the cylindrical power storage body 14 are connected to the positive electrode bus bar 16 and the negative electrode bus bar 18, respectively, via conductive bearings 28. The positive electrode bus bar 16 and the negative electrode bus bar 18 are both formed of conductive plates 16a, 18a, and are fixed to the lid portion 10b and the bottom portion 10c of the case 10a of the battery module 10, respectively (see FIG. 3). In this embodiment, the lid portion 10b and the bottom portion 10c of the battery module 10 are fixed to the lid portion 12b and the bottom portion 12c of the housing 12a of the battery pack 12. The positive electrode bus bar 16 and the negative electrode bus bar 18 are fixed to the lid portion 10b and the bottom portion 10c of the case 10a using rivets (fixing devices) 30, respectively. Rivets 30 are also used to fasten cover 10b and bottom 10c of case 10a to cover 12b and bottom 12c of housing 12a.

[0023] The connection between the positive bus bar 16 and the negative bus bar 18 and the cylindrical power storage body 14 is, for example, as shown in FIG. 4, by forming a circular hole 18b in the conductive plate 18a constituting the negative bus bar 18, and fixing the outer ring 28a of the conductive bearing 28 to the hole 18c. This fixing is, for example, by forming a ring-shaped protrusion 18c in the conductive plate 18b, fitting the outer ring 28a of the conductive bearing 28 into the ring-shaped protrusion 18c, and connecting and fixing by, for example, welding. Then, the negative electrode 14b of the cylindrical power storage body 14 is connected and fixed to the inner ring 28b of the conductive bearing 28. This fixing can also be performed by welding. The positive electrode 14a side of the cylindrical power storage body 14 is similarly performed. The inner ring 28b and the outer ring 28a of the conductive bearing 28 are configured to be conductive. Therefore, the cylindrical power storage body 14 is rotatable in a state in which both electrodes are electrically connected to the bus bars 16 and 18.

[0024] According to the above-mentioned configuration, the cylindrical electric power storage bodies 14 are arranged in the case 10a at intervals so that the cooling fluid can flow. Then, the cylindrical electric power storage bodies 14 are cooled by the cooling air that flows from the fluid inlet 20 and flows in a direction perpendicular to the axial direction of the cylindrical electric power storage bodies 14. When the cooling air hits the cylindrical electric power storage bodies 14, the cylindrical electric power storage bodies 14 rotate due to the wind force of the cooling air, since the cylindrical electric power storage bodies 14 are rotatably mounted by the conductive bearings 28. As a result, the entire circumferential surface is effectively cooled, and even if a part of the cylindrical electric power storage body 14 generates heat, the cooling air hits the heated part evenly. Furthermore, since the cylindrical electric power storage bodies 14 rotate, heat is also dissipated to the surroundings, so that all the cylindrical electric power storage bodies 14 can be cooled efficiently and evenly.

[0025] In addition, the cylindrical storage batteries 14 are arranged in multiple rows, and the fluid inlets 20 are arranged so that a fluid flow path 30 is formed between the multiple rows through which cooling air flows, and when there are three or more rows of cylindrical storage batteries 14, the fluid inlets 20 are provided so that the flow directions of the cooling air are opposite in adjacent fluid flow paths 30.

[0026] With this configuration, the flow directions of the cooling air are opposite to each other in the adjacent fluid flow paths 30. Therefore, for each of the cylindrical power storage bodies 14, the direction of the rotational force applied by the cooling air flowing through the fluid flow path 30 on one side coincides with the direction of the rotational force applied by the cooling air flowing through the fluid flow path 30 on the other side. This prevents the reduction in rotational force that occurs when the cooling air flows in the same direction through the fluid flow paths 30 on both sides. In other words, the rotational force of the cooling air acts on the cylindrical power storage body 14 in the same direction, and the rotation of the cylindrical power storage body 14 by the cooling air becomes more effective. This allows the rotation speed of the cylindrical power storage body 14 to be maintained at a good level, and allows the cylindrical power storage body 14 to be cooled more efficiently and evenly.

[0027] Furthermore, the cylindrical power storage bodies 14 are arranged in a row in a zigzag pattern in the direction in which the row extends. With this configuration, the cylindrical power storage bodies 14 are arranged not in a linear row but in a zigzag pattern extending to the left and right, and the fluid flow path 30 also becomes a zigzag flow path. Therefore, the cooling air collides more strongly with the cylindrical power storage bodies 14 arranged out of a straight line. Therefore, the cylindrical power storage bodies 14 receive a stronger rotational force from the cooling air, and the rotation speed increases, making it possible to cool the cylindrical power storage bodies 14 more efficiently.

[0028] Moreover, the positive bus bar 16 and the negative bus bar 18 are configured as plate-shaped positive conductive plate 16a and negative conductive plate 18b, respectively, and a conductive bearing 28 is used as the rotating member. Holes 16b, 18b are formed in each conductive plate, and an outer ring 28a of the conductive bearing 28 is connected and fixed to the holes 16b, 18b. The inner ring 28b of the conductive bearing 28 is connected and fixed to the positive electrode 14a or negative electrode 14b of the cylindrical power storage unit 14.

[0029] With this configuration, cylindrical power storage body 14 is electrically connected to positive electrode side bus bar 16 and negative electrode side bus bar 18 without a complicated configuration and is clamped and held in a rotatable state. That is, outer ring 28a of conductive bearing 28 is connected and fixed to conductive plates 16a, 18a, which are bus bars, respectively, and inner ring 28b is connected and fixed to positive electrode 14a or negative electrode 14b, respectively, of cylindrical power storage body 14, ensuring a state in which each cylindrical power storage body 14 is held in a state in which it can be electrically connected to positive electrode side bus bar 16 and negative electrode side bus bar 18 and can be rotated about the cylindrical axis.

[0030] Next, an embodiment of cooling by the cooling fan 26 of the battery module 10 will be described. The battery pack 12 is equipped with a temperature sensor (not shown) that measures the temperature of each of the cylindrical power storage bodies 14, and a control unit (not shown) that controls the cooling fan 24 so that cooling air is circulated on both sides of the row to which the cylindrical power storage body 14 that has exceeded the predetermined temperature belongs, when the temperature measured by the temperature sensor exceeds a predetermined temperature.

[0031] If the temperature sensor is used in, for example, an infrared camera, it is possible to measure the temperature of each cylindrical power storage body 14 and predict a temperature rise.

[0032] In this embodiment, as shown in FIG. 5, when a specific cylindrical power storage body 14 (referred to as cylindrical power storage body A) becomes hot, cooling air is sent from the fluid inlet 20 to the fluid flow path 30 on both sides of the row including the cylindrical power storage body A. The direction of the cooling air flow is opposite on both sides of the row, and the cylindrical power storage body 14 arranged in a staggered manner and arranged to protrude in the fluid flow path 30 receives a strong wind force of the cooling air, and all the cylindrical power storage bodies 14 including the cylindrical power storage body A in the row rotate in the same direction. This rotation allows the cylindrical power storage body A, which has become hot, to be evenly cooled by the cooling air. In addition, the rotation also has the effect of dissipating heat, and the cylindrical power storage body A is efficiently cooled. Therefore, this configuration makes it possible to pinpoint and cool the cylindrical power storage body 14 whose temperature has risen to a predetermined temperature or higher. In other words, compared to the case where cooling air is circulated over the entire battery module 10, only the heated cylindrical power storage body 14 is cooled, so that the power consumption for cooling can be reduced while efficiently reducing the temperature variation of the cylindrical power storage body 14.

[0033] As described above, the timing for introducing cooling air includes when a specific cylindrical power storage body A becomes hot, and when temperature variations are measured or predicted within the battery module 10. Furthermore, even if there is no temperature variation, cooling air is also ventilated when the temperature of the entire battery module 10 rises due to long-term use of the battery module 10. In this case, cooling air is sent from all of the inlets 22 to cool the entire battery module 10.

[0034] The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. For example, the cylindrical power storage bodies 14 are arranged in a staggered manner in the battery module 10, but may be arranged in a line. Also, fins may be provided on the cylindrical power storage bodies 14 to make them easier to rotate by receiving cooling air. Furthermore, the outer ring 28a of the conductive bearing 28 is connected and fixed to the conductive plates 16a, 18a by forming holes 16b, 18b and ring-shaped protrusions 16c, 18c in the conductive plates 16a, 18a, but the present invention is not limited to this. For example, the outer ring 28a of the conductive bearing 28 may be directly fixed to the conductive plates 16a, 18a. [Explanation of symbols]

[0035] 10 Battery module 10a Case 10b Lid 10c bottom 12 Battery pack 12a Housing 12b Lid 12c bottom 14 Cylindrical electricity storage unit 14a positive electrode 14b negative electrode 16 Positive bus bar 16a Positive electrode conductive plate 16b Hole 16c protrusion 18 Negative bus bar 18a Negative conductive plate 18b Hole 18c protrusion 20 Fluid inlet 22 Fluid outlet 24 Cooling fan (fluid injection mechanism) 26 Connectors 28 Conductive Bearing 28a Inner Circle 28b Outer ring 30 Rivets (fixing parts) 32 Duct 34 Filters

Claims

1. A battery module comprising: a plurality of cylindrical power storage bodies; and a case in which the cylindrical power storage bodies are housed; the cylindrical power storage bodies are held in the case by a positive bus bar that is provided in the case and electrically connected to positive electrodes of all of the housed cylindrical power storage bodies; and a negative bus bar that is provided in the case and electrically connected to negative electrodes of all of the housed cylindrical power storage bodies; and the cylindrical power storage bodies are charged and power is supplied from the cylindrical power storage bodies to a load via the positive bus bar and the negative bus bar, a battery module characterized in that the cylindrical accumulators are arranged with a gap between adjacent cylindrical accumulators to allow a cooling fluid to flow, each cylindrical accumulator is held by the positive side bus bar and the negative side bus bar in such a way that the cylindrical accumulators are rotatably attached to the positive side bus bar and the negative side bus bar via an electrically conductive rotating member, and the case is provided with a fluid inlet for allowing the cooling fluid to flow into the cylindrical accumulator from a direction perpendicular to the axial direction of the cylindrical accumulator.

2. The cylindrical electricity storage bodies are arranged in a plurality of rows, The fluid inlet ports are arranged between the rows of the plurality of rows so as to form fluid flow paths through which the fluid flows, The battery module according to claim 1, characterized in that when there are three or more rows of cylindrical storage batteries, the fluid inlets are arranged so that the flow directions of the fluid in adjacent fluid flow paths are opposite to each other.

3. The cylindrical storage batteries are arranged in a row, 3. The battery module according to claim 2, wherein the rows are arranged in a zigzag pattern in the extending direction of the rows.

4. a temperature sensor for measuring the temperature of each of the cylindrical power storage bodies; a fluid pouring mechanism for pouring the fluid from the fluid introduction inlet; The battery module described in claim 3, characterized in that it is further equipped with a control unit that controls the operation of the fluid pouring mechanism so that, when the temperature measured by the temperature sensor exceeds a predetermined temperature, the fluid is poured to both sides of the column to which the cylindrical storage battery that has exceeded the predetermined temperature belongs.

5. the positive bus bar and the negative bus bar are respectively configured as a plate-shaped positive conductive plate and a plate-shaped negative conductive plate, The rotating member is made of a conductive bearing, the positive electrode side conductive plate is provided on the upper side of the case, and the negative electrode side conductive plate is provided on the lower side of the case, the positive electrode side conductive plate and the negative electrode side conductive plate have holes to which the outer rings of the conductive bearings are connected and fixed, The inner rings of the conductive bearings are connected and fixed to the positive and negative electrodes of the cylindrical storage body, The cylindrical electric storage body is held by the positive electrode side conductive plate and the negative electrode side conductive plate, 2. The battery module according to claim 1, wherein each of the cylindrical storage batteries is sandwiched between the positive electrode side conductive plate on the upper side of the case and the negative electrode side conductive plate on the lower side of the case via the conductive bearing.

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