JP5613630B2 - Power storage module - Google Patents

Description

  The present invention relates to a power storage module, and more particularly to a power storage module having a cooling function.

Secondary battery cells such as lithium ion secondary battery cells, nickel hydride secondary battery cells, and nickel cadmium secondary battery cells have been rapidly spreading in recent years as power sources for hybrid vehicles and electric vehicles.
A secondary battery cell used as a power source for an automobile is usually a power storage module in which a plurality of secondary battery cells are connected in series with a bus bar.
The secondary battery cell generates heat due to the current flowing when charging / discharging and the internal resistance, and may be used in a high temperature environment, so that it is a battery module having a cooling function. There are many cases.

The following structure is known as a battery module having a cooling function.
A pair of air ducts are provided above and below an assembled battery configured by connecting a plurality of secondary battery cells, and a pair of circulation chambers are provided outside the air duct. Further, the secondary battery cells are arranged apart from each other, and a cooling duct connected to the air duct at both ends and a heat exchange pipe connected to the circulation chamber at both ends are arranged between the secondary battery cells.
Air is supplied from a cooling fan into the air duct, and heat exchange liquid is circulated by a liquid circulator in the heat exchange pipe to cool each secondary battery cell (for example, see Patent Document 1).

JP 2009-9888 A

  The battery module described in Patent Document 1 has a large number of cooling members such as an air duct, a cooling duct, a circulation chamber, a heat exchange pipe, and the like, and a cooling duct and a heat exchange pipe are disposed between the secondary battery cells. Since the structure is complicated, the manufacturing cost is increased.

The power storage module of the present invention contains a power generation element having positive and negative electrode plates in a battery container, and positive and negative external terminals connected to the positive and negative electrode plates are arranged on one side of the battery container. An assembled battery in which a plurality of secondary battery cells are electrically connected, a cooling structure portion that is thermally coupled to the other side opposite to one side of each secondary battery cell, the assembled battery, and cooling a case for accommodating the structural unit, are housed in the case, and a fan disposed in the space between the one side of the assembled battery and the case, the fan, the air in the casing, the cooling structure portion blown towards, and through the space between the periphery and the inner surface of the case of the cooling structure unit, the fan is moved to the space opposite to the can placed side, further, the side opposite to the fan is arranged side Move the fan to the opposite side of the cooling structure along the side of the case. The A side is moved while cooling the positive and negative electrode external terminal of the space arranged fan from a space opposite sides, and characterized in that to convection to blow back toward the cooling structure portion To do.

According to the power storage module of the present invention, the air in the case is blown toward the cooling structure by the fan, and the air in the case passes between the periphery of the cooling structure and the inner surface of the case along the blowing direction. Convection. By causing air convection in the case, the positive and negative portions on the external terminal side that are likely to become high temperature are cooled. Thus, by improving the cooling efficiency, the number of partial points can be reduced and the structure can be simplified, so that the manufacturing cost can be reduced.

(A) is a side view of one embodiment of the electricity storage module of the present invention, (b) is a plan view cut along the Ib-Ib line of 1 (a). FIG. 2 is an external perspective view of the assembled battery illustrated in FIG. FIG. 3 is an external perspective view of a secondary battery cell constituting the assembled battery illustrated in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV of the assembled battery illustrated in FIG. 2. The expansion perspective view of the electric power generation element accommodated in the secondary battery cell. FIGS. 1A and 1B are enlarged cross-sectional views of the cooling structure shown in FIG. The block diagram which shows an example of the outline of a cooling system. The side view of Embodiment 2 of the electrical storage module of this invention. The side view of Embodiment 3 of the electrical storage module of this invention.

--Embodiment 1-
[Energy storage module overall configuration]
Hereinafter, an embodiment of a power storage module of the present invention will be described with reference to the drawings.
The power storage module of the present invention can be applied, for example, as a power storage device for an in-vehicle power supply device of an electric vehicle, particularly an electric vehicle. The electric vehicle includes a hybrid electric vehicle including an engine that is an internal combustion engine and an electric motor as a driving source of the vehicle, and a genuine electric vehicle using the electric motor as the only driving source of the vehicle.
Fig.1 (a) is a side view as one Embodiment of the electrical storage module of this invention, FIG.1 (b) is the top view cut | disconnected by the Ib-Ib line | wire of Fig.1 (a).
The power storage module 1 has a case 31. In the case 31, an assembled battery 20 formed by connecting a plurality of battery cells 10, a cooling structure 50 disposed at a lower portion of the assembled battery 20, and a battery cell 10 on one end side of the assembled battery 20, An electric fan 35 disposed in the space between the inner surface of the case 31 is accommodated.
The cooling medium 50 flows into the cooling structure 50 from the x direction into the cooling structure 50, and heat exchange with the heat generated by each battery cell 10 of the assembled battery 20 in the cooling structure 50 cools each battery cell 10. Thereafter, a pipe 33 for flowing out the cooling medium from the power storage module 1 is connected.

FIG. 2 is an external perspective view of the assembled battery illustrated in FIG. 1A, and FIG. 3 is an external perspective view of a secondary battery cell constituting the assembled battery illustrated in FIG.
In the present embodiment, the assembled battery 20 includes eight battery cells 10 that are electrically connected to each other. However, the number of the battery cells 10 is not limited to eight, and can be an arbitrary number of more or less. In this embodiment, each battery cell 10 is illustrated as a lithium ion secondary battery cell.

[Battery cell structure]
Each battery cell 10 has a positive external terminal 11 and a negative external terminal 12 exposed to the outside from one side surface of the battery container.
Each battery cell 10 is alternately reversed so that adjacent battery cells are opposite to each other so that the positive electrode external terminal 11 and the negative electrode external terminal 12 face the external terminals 12 and 11 of the opposite polarity. They are arranged in parallel.
That is, each battery cell 10 is arranged such that the positive electrode external terminal 11 faces the negative electrode external terminal of the adjacent battery cell 10 and the negative electrode external terminal 12 faces the positive electrode external terminal 11.
A positive external terminal 11 of one battery cell 10 adjacent to each other and a negative external terminal 12 of the other battery cell 10 are connected by a bus bar 13. Thereby, all the battery cells 10 which comprise the assembled battery 20 are connected in series.

  However, the positive external terminal 11 of the battery cell 10 located at the foremost part (the leftmost in FIG. 1A and FIG. 2) of the assembled battery 20 and the rearmost (the rightmost in FIG. 1A and FIG. 2) The negative electrode external terminal 12 of the battery cell 10 located at () is not connected to the bus bar 13.

Each battery cell 10 has a battery container including a battery can 2 having a bottom and an upper portion opened, and a battery lid 3 covering the opened upper portion of the battery can 2. The battery container has an elongated rectangular bottom surface, a pair of large-area side surfaces adjacent to the long side of the bottom surface, and a pair of small-area side surfaces adjacent to the short side of the bottom surface.
A positive electrode external terminal 11 and a negative electrode external terminal 12 of each battery cell 10 are provided on the battery lid 3. Between the positive electrode external terminal 11 and the negative electrode external terminal 12 in the battery lid 3, a cleavage valve 14 and a liquid injection part 15 for injecting an electrolytic solution into the battery container are formed.

  The cleavage valve 14 has a function of discharging gas generated inside when the abnormality occurs such as heat generation due to overcharge or internal short circuit and the pressure in the battery cell 10 is increased. The cleavage valve 14 has a structure in which a groove having a V-shaped or U-shaped cross section is formed in a part of the battery lid 3 by pressing, and the remainder is thin. The thinned portion formed by forming a groove having a V-shaped or U-shaped cross section is cleaved by the pressure of the gas generated in the battery container, and a mist-like gas containing the electrolytic solution is released to the outside. The

  Although not shown, the liquid injection part 15 is composed of an opening formed in the battery lid 3 and a liquid injection stopper that closes the opening. After injecting the electrolyte into the battery can 2 through the opening, the opening is closed with a filling plug, and this filling plug is joined to the peripheral edge of the opening of the battery lid 3 by laser welding. Seal the container.

[Battery structure]
4 is a cross-sectional view taken along line IV-IV of the battery pack illustrated in FIG.
The positive electrode external terminal 11 and the negative electrode external terminal 12 in each battery cell 10 each have a bolt-like structure having a large-diameter base portion 23 and a small-diameter mounting portion 24 in which a male screw is formed.
The bus bar 13 that connects the positive and negative external terminals 11 and 12 facing each other in the adjacent battery cell 10 is fixed by a nut 21 that meshes with the male screw of the positive and negative external terminals 11 and 12.

  The battery lid 3 of the battery cell 10 is formed with a through hole into which an insulating member 16 having an opening at the center is fitted. The electrode connection plate 17a or 17b is fitted in the through hole formed in the insulating member 16.

One electrode connection plate 17 a and the positive electrode current collector plate 18 a are caulked and fixed to the battery lid 3. The electrode connection plate 17a and the positive electrode current collector plate 18a are made of an aluminum-based metal.
The other electrode connection plate 17 b and the negative electrode current collector plate 18 b are caulked and fixed to the battery lid 3. The electrode connection plate 17b and the negative electrode current collector plate 18b are formed of a copper-based metal.
The positive electrode current collector plate 18a and the negative electrode current collector plate 18b are bent in a substantially vertical direction from the attachment portion attached to the battery lid 3, and further inclined toward the center portion side in the thickness direction of the battery cell. On the part side, it again has a shape bent in a direction perpendicular to the mounting part.

The positive and negative current collecting plates 18 a and 18 b and the electrode connecting plates 17 a and 17 b are insulated from the battery lid 3 by the insulating member 16.
A positive external terminal 11 or a negative external terminal 12 is connected to each electrode connection plate 17a, 17b. This connection can be made by caulking the positive electrode external terminal 11 or the negative electrode external terminal 12 and each electrode connection plate 17a, 17b directly or via a conductive connection plate (not shown).

  The adjacent positive external terminal 11 and negative external terminal 12 are connected by a bus bar 13. The bus bar 13 is formed with a through hole through which the attachment portion 24 of the positive external terminal 11 and the negative external terminal 12 is inserted. The bus bar 13 is attached to the attachment portions 24 of the positive and negative external terminals 11 and 12 by inserting the through holes, and the nut 21 is fastened to the screw of each attachment portion 24 to fix the bus bar 13. In this state, the positive external terminal 11 and the negative external terminal 12 are electrically connected by the bus bar 13.

  Each battery container contains a power generation element 6 formed by winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween. The positive electrode current collector plate 18a is joined to the positive electrode plate, and the negative electrode current collector plate 18b is joined to the negative electrode plate by ultrasonic welding.

[Structure of power generation element]
FIG. 5 is an enlarged perspective view of the power generation element 6.
As shown in FIG. 5, the power generation element 6 has a flat wound structure in which a separator 6C, a negative electrode plate 6D, a separator 6C, and a positive electrode plate 6E are stacked in this order, wound around a plurality of times, and crushed into a flat shape. The power generation element 6 is reduced in weight by omitting the shaft core, and as a substitute for the shaft core, a separator 6C is wound around the winding start end (power generation element central portion) several times. In addition, the separator 6C is wound several times around the winding end (power generation element surface layer) to ensure insulation, and in order to prevent unwinding, one side of the winding end of the separator 6C is It is stopped by a tape (not shown) coated with an adhesive.

  In the positive electrode plate 6E, a positive electrode active material mixture containing, for example, a lithium-containing transition metal double oxide such as lithium manganate as a positive electrode active material on both surfaces of an aluminum alloy foil (positive electrode current collector foil) is substantially uniform and substantially uniform. It is made by coating. On both sides of the aluminum alloy foil, a positive electrode uncoated portion 6A in which the positive electrode active material mixture is not applied and the aluminum alloy foil is exposed is formed on one side along the longitudinal direction.

  In the negative electrode plate 6D, a negative electrode active material mixture containing a carbon material such as graphite capable of occluding and releasing lithium ions as a negative electrode active material on both surfaces of a copper alloy foil (negative electrode current collector foil) is substantially uniform and substantially uniform. It is made by painting. On both sides of the copper alloy foil, a negative electrode active material mixture is not coated on one side along the longitudinal direction, and a negative electrode uncoated portion 6B in which the copper alloy foil is exposed is formed. The positive electrode uncoated portion 6 </ b> A and the negative electrode uncoated portion 6 </ b> B are provided at opposite peripheral edge portions of the power generation element 6.

  The length of the negative electrode plate 6D in the winding direction is such that when the positive electrode plate 6E and the negative electrode plate 6D are wound, the positive electrode plate 6E protrudes from the negative electrode plate 6D in the winding direction at the innermost winding and the outermost winding. In order to prevent this, it is set longer than the length of the positive electrode plate 6E. In addition, the length in the direction orthogonal to the winding direction of the negative electrode active material mixture applied to the negative electrode plate 6D, in other words, the length in the width direction is the positive electrode active material mixture applied to the positive electrode plate 6E. It is formed larger than the width of the agent. Therefore, also in the width direction, the positive electrode active material mixture applied to the positive electrode plate 6E does not protrude beyond the negative electrode active material mixture applied to the negative electrode plate 6D. If there is a portion of the negative electrode current collector foil that does not face the positive electrode active material, lithium contained in the positive electrode active material is ionized, penetrates the separator, and deposits on that portion. Thereby, an internal short circuit may occur. Thus, it can prevent by making a negative electrode active material area | region wider than a positive electrode active material area | region.

  The separator 6C is made of a microporous sheet material through which lithium ions can pass. In this example, a polyethylene sheet having a thickness of several tens of μm is used.

As described above, the power generation element 6 has a flat winding structure in which the separator 6C, the negative electrode plate 6D, the separator 6C, and the positive electrode plate 6E are stacked in this order and wound around a plurality of times, and are flattened.
As shown in FIG. 5, the positive electrode uncoated portion 6A and the negative electrode uncoated portion 6B in the power generation element 6 having the flat wound structure are arranged around the shaft core on one end side and the other end side in the width direction, respectively. To form a multilayer structure in which the wound portions are polymerized with each other.

The positive electrode current collector plate 18a is joined by ultrasonic welding to the positive electrode uncoated portion 6A in which the wound portions are polymerized with each other. The polymerized positive electrode uncoated portions 6A are also joined to each other by ultrasonic welding.
The negative electrode current collector plate 18b is joined by ultrasonic welding to the negative electrode uncoated portion 6B in which the wound portions are polymerized with each other. The polymerized negative electrode uncoated portions 6B are also joined to each other by ultrasonic welding.

  After connecting the positive and negative external terminals 11 and 12 to the positive and negative uncoated portions 6A and 6B of the power generation element 6 by the positive and negative electrode plates 18a and 18b, the peripheral portion of the battery lid 3 is laser-welded. Join the battery can 2. Then, a non-aqueous electrolyte is injected from an opening provided in the liquid injection part 15 of the battery lid 3, and the battery cell 10 shown in FIG. 3 is manufactured by sealing the opening with a liquid injection stopper. The As an example of the non-aqueous electrolyte, a solution in which a lithium salt is dissolved in a carbonate solvent can be used.

[Structure of cooling structure]
In FIG. 1A, a cooling structure portion is provided on the bottom side of each battery cell 10 constituting the assembled battery 20, in other words, on the opposite side of the battery lid 3 provided with the external terminals 11 and 12 on the positive and negative electrodes. 50 is disposed in thermal coupling with each battery cell 10.
FIG. 6 is an enlarged cross-sectional view of the cooling structure 50 shown in FIGS. 1 (a) and 1 (b).
The cooling structure 50 includes a cooling medium 51, a pipe 33 that serves as a passage through which the cooling medium 51 circulates, a cooling plate 52 that is in close contact with the outer surface of the pipe 33, one surface that is in close contact with the cooling plate 52, and the other surface that is The heat conductive sheet 53 is in close contact with the bottom of the battery cell 10.

As the cooling medium 51, for example, a liquid such as a fluorine-based inert liquid or silicon oil can be used.
The pipe 33 is formed of SUS or the like and extends in the arrangement direction of the battery cells 10. As shown in FIG. 1B, a plurality of pipes 33 (shown as two in FIG. 1B) are arranged in parallel.
The cooling plate 52 is made of, for example, aluminum having high thermal conductivity, and has an area that is substantially the same as or larger than the area of the bottom of the assembled battery 20.
The heat conductive sheet 53 is formed of a flexible thin insulator having adhesiveness on both the front and back surfaces, and is well thermally coupled to the bottom of each battery cell 10 of the assembled battery 20.

As illustrated in FIG. 1A, an electric fan 35 is provided in the space between the outer side surface and the inner surface of the case 31 among the pair of large area side surfaces of the battery cell 10 on one end side of the assembled battery 20. Is housed. The electric fan 35 is disposed between the bottom of the battery cell 10 and the battery lid 3 in the height direction.
When the electric fan 35 is driven at this position, the air in the case 31 is drawn from the upper side of the electric fan 35 and blown to the lower side in the case 31. Thereby, the air in the case 31 moves in the direction of the arrow y, and further moves in the direction of the arrow x along the bottom surface of the case 31, and passes between the surface of the cooling structure 50 and the inner surface of the case 31. . An arrow AR in FIG. 1B indicates the direction of the cooling air flowing around the cooling structure 50. The cooling structure 50 performs heat exchange with each battery cell 10 by the cooling medium 51 circulating in the pipe 33, and cools each battery cell 10 from the bottom side. Moreover, the air which contacted the surface of each battery cell 10 and became high temperature is cooled.

  The cooled air rises from bottom to top along the side surface of the case 31, and is a space between the upper inner surface of the case 31 and each battery cell 10 on the side opposite to the space where the electric fan 35 is disposed. Is further drawn into the electric fan 35. Then, the electric fan 35 blows air again in the direction of the arrow y. In this manner, by driving the electric fan 35, the air in the case 31 is moved along the inner surface of the case 31 to forcibly generate convection.

  Each battery cell 10 generates heat due to the current flowing through the power generation element 6 and the internal resistance during charging and discharging. Since the cooling structure 50 is thermally coupled to the bottom side of the battery container of each battery cell 10, the bottom side of the battery container is quickly cooled. On the other hand, the cooling effect by the cooling structure 50 is reduced by the distance from the cooling structure 50 on the battery lid 3 side. For this reason, the positive and negative external terminals 11 and 12 are likely to be hot.

  Thus, a large temperature difference tends to occur between the bottom side of the battery cell 10 and the positive and negative external terminals 11 and 12 side. In order to sufficiently cool the positive and negative external terminals 11 and 12 side in a state where a large temperature difference has occurred, it is necessary to make the cooling capacity extremely large, which is inefficient. Further, if a large number of parts are used or the arrangement of cooling pipes is complicated in order to increase the cooling capacity, the manufacturing cost of the power storage module increases.

On the other hand, in the power storage module 1 of the present embodiment, the electric fan 35 is driven to blow air toward the cooling structure 50, and the air in the case 31 is shown as an arrow AR in FIG. The space between the inner surface of 31 and the assembled battery 20 is moved to forcibly generate convection. For this reason, the heat conducted to the positive and negative external terminals 11 and 12 of the battery cell 10 is cooled by the convection air.
In the present embodiment, the electric fan 35 is the only member that causes air convection in the case 31. The case 31 and the assembled battery 20 need not be changed in particular, structure, or shape. In addition, the arrangement of the piping 33 is also linear, and does not have a curved portion that crosses the assembled battery 20.
As described above, since the power storage module 1 having a small number of parts and a simple structure and high cooling efficiency can be realized, the manufacturing cost of the power storage module 1 can be reduced.

[Whole system]
In the power storage module 1 illustrated in FIG. 1A, the positive external terminal 11 of the battery cell 10 positioned at the foremost part not connected to the bus bar 13 is the negative external terminal of the last battery cell 10 of another battery module. 12 or connected to the high potential side of the inverter device (not shown). Further, in the power storage module 1, the negative electrode external terminal 12 of the battery cell 10 located at the end not connected to the bus bar 13 is connected to the positive electrode external terminal of the battery cell in the front row of another battery module or illustrated. Although not, it is connected to the low potential side of the inverter device.
In this way, a plurality of power storage modules 1 are connected in series to form a high-voltage battery module device, which is connected to an inverter device (not shown).

  The inverter device converts DC power from the battery module device into three-phase AC power. For example, in the case of a vehicle driving system, the inverter device drives an electric motor / generator. In the state where the motor / generator is driven as a generator, regenerative power is supplied to the inverter device to charge each battery cell 10.

  Although not shown, each bus bar 13 of the assembled battery 20 is connected to an IC including a differential amplifier and a microcomputer functioning as a host controller of the IC through a multiplexer by a connection conductor for voltage detection. The battery cells 10 to be connected are sequentially switched by the multiplexer, and the voltage of the battery cell 10 is detected by the differential amplifier. The detected voltage of each battery cell 10 is converted into a digital value by the A / D conversion circuit and held in the storage unit of the microcomputer. When it is detected that each battery cell 10 is overcharged, a balancing switch (not shown) disposed between the positive terminal and the negative terminal of each battery cell 10 is turned on, and each battery cell 10 is turned on. Discharge.

A cell controller composed of a microcomputer and a plurality of ICs controls the measurement of the voltage, total voltage, and current of each battery cell 10, and also controls charging and discharging.
The microcomputer adjusts the rotational speed of the cooling electric fan 35 for cooling the assembled battery 20 or the supply amount of the cooling medium based on the input temperature of each battery cell 10 or the average temperature of the assembled battery 20 and Controls the pump speed.

[Cooling system]
FIG. 7 is a configuration diagram illustrating an outline of an example of the cooling system.
In FIG. 7, the power storage module device is illustrated as one power storage module 1. However, as described above, a plurality of power storage modules 1 can be connected in series.
The cooling structure 50 of the power storage module 1 is connected to a pump 71, a tank 72, and a radiator 73 via a pipe 33. The pipe 33, the pump 71, the tank 72, and the radiator 73 form a cooling loop that circulates the cooling medium 51 that flows in the pipe 33.

The pump 71 is of a hydraulic or electric type, sucks the cooling medium 51 stored in the tank 72 and pushes it out into the pipe 33, moves the pipe 33 in the direction of the arrow x, and cools the power storage module 1. 50. When the cooling medium 51 passes through the cooling structure 50, the cooling medium 51 performs heat exchange with the heat accumulated in each battery cell 10 of the power storage module 1 to cool each battery cell 10. The cooling medium 51 whose temperature has increased by exchanging heat with the battery cell 10 flows out of the power storage module 1 and is cooled by the radiator 73. The radiator 73 performs heat exchange with the atmosphere, for example.
The tank 72 has a function as a buffer that temporarily stores the cooling medium 51 and absorbs a volume change of the cooling medium 51 due to a temperature change or the like.
As described above, the rotational speed of the pump 71 is controlled by a microcomputer (not shown) based on the temperature of each battery cell 10 or the average temperature of the assembled battery 20, and the supply amount of the cooling medium 51 to the cooling structure 50 is adjusted. The Further, the microcomputer controls the rotational speed of the electric fan 35 and adjusts the amount of air convection between the cooling structure 50 and the upper side of the assembled battery 20.

[Example]
As shown in FIGS. 1A and 1B, the cooling plate 52 is accommodated in the case 31, and the piping 33 is provided from the outside of the case 31 to the inside of the case 31 and the through holes provided in the cooling plate 52. (Not shown) was inserted. The heat conductive sheet 53 was adhered to the upper surface of the cooling plate 52 to form the cooling structure 50 in the case 31.
The assembled battery 20 was disposed on the upper surface of the heat conductive sheet 53 and the bottom of each battery cell 10 of the assembled battery 20 was placed in close contact with the heat conductive sheet 53.

  Of the pair of large-area side surfaces of the battery cell 10 on one end side of the assembled battery 20, the electric fan 35 is disposed in a space between the outer side surface and the inner surface of the case 31. The position of the electric fan 35 in the height direction was intermediate between the battery lid 3 of the battery cell 10 and the bottom of the battery can 2.

  The electric fan 35 was driven to blow the air in the case 31 toward the lower part of the case 31 as indicated by an arrow y. The air in the case 31 moved in the direction of the arrow x along the inner surface of the bottom portion of the case 31, and moved from the bottom to the top in the space opposite to the space where the electric fan 35 was arranged. Furthermore, it moved through the space between the upper inner surface of the case 31 and the assembled battery 20 and sent out from the electric fan 35 again, and thus air convection occurred along the inner surface of the case 31. The air volume by the electric fan 35 was 4 CFM (Cubic Feet per Minute).

In this state, the temperature was measured at two points, the positive and negative external terminals 11 and 12 of the battery cell 10 and the bottom of the battery can 2.
As a comparative example, the temperature was measured at two points of the positive and negative external terminals 11 and 12 of the battery cell 10 and the bottom of the battery can 2 under the same conditions as when the electric fan 35 was not driven. .

  The temperature difference between the positive and negative external terminals 11 and 12 and the bottom of the battery can 2 in the above example and the comparative example was smaller in the example than in the comparative example.

[Effect of Embodiment 1]
In the power storage module 1 of the present invention shown in the first embodiment, the cooling medium 51 is exchanged with the heat generated by each battery cell 10 of the assembled battery 20 by the cooling system shown in FIG. Circulate.
The electric fan 35 provided in the case 31 of the power storage module 1 is driven to blow air toward the cooling structure 50, and the air in the case 31 cools the space between the inner surface of the case 31 and the assembled battery 20. Convection of air moving from the structure 50 toward the positive and negative external terminals 11 and 12 is forcibly generated.
The heat generated inside each battery cell 10 and conducted to the positive and negative external terminals 11 and 12 and the battery lid 3 side is cooled by air convection in the case 31. Thereby, the temperature difference between the cooling structure 50 side and the positive and negative external terminals 11 and 12 on the opposite side is reduced.
As described above, the cooling efficiency can be improved with a simple structure in which the electric fan 35 is disposed in the case 31, and the manufacturing cost can be reduced.
In addition, since the electric fan 35 is disposed at an intermediate position between the bottom and the upper part of the battery cell 10, the electric fan 35 draws in air from the upper side and the cooling structure unit 50 disposed on the lower side. Air blowing becomes efficient.

--Embodiment 2-
FIG. 8 is a side view of Embodiment 2 of the electricity storage module of the present invention.
The power storage module 1 shown in the second embodiment is different from the first embodiment in that a duct 55 is provided in the case 31 to guide the movement of air drawn into the electric fan 35 and blown from the electric fan 35. It is a point.
As in the case of the first embodiment, the electric fan 35 is disposed in a space between the outer side surface and the inner surface of the case 31 among the pair of large-area side surfaces of the battery cell 10 on one end side of the assembled battery 20. ing. The position of the electric fan 35 in the height direction is intermediate between the battery lid 3 of the battery cell 10 and the bottom of the battery can 2.

The duct 55 is disposed so that the upper part is in contact with the inner surface of the upper side of the case 31. The duct 55 extends to the vicinity of the bottom of the battery cell 10 and faces the pipe 33 on the inflow side of the cooling structure 50.
In the upper part of the duct 55, an inlet 55a into which air moving along the inner surface of the case 31 flows is formed. The duct 55 takes in air that has been moved between the assembled battery 20 and the inside of the upper portion of the case 31 by convection from the inlet 55a and guides it to the electric fan 35 side. For this reason, the convection generated by the electric fan 35 becomes smoother, and the cooling efficiency on the positive and negative external terminals 11 and 12 side of each battery cell 10 is improved.

  An inclined portion 55b is formed at a corner portion of the duct 55 facing the inlet 55a. The inclined portion 55b is formed so as to incline over the upper side surface and the side surface provided in a direction perpendicular to the upper side surface. The direction of the air flowing in from the inlet 55a is smoothly changed in the direction of the electric fan 35 in the inclined portion 55b.

  In the second embodiment, other configurations are the same as those of the first embodiment, and the corresponding members are denoted by the same drawing numbers and the description thereof is omitted.

In the second embodiment, the same effect as in the first embodiment can be obtained.
In the second embodiment, the duct 55 for guiding the air drawn into the electric fan 35 is provided in the case 31, so that the convection flow generated in the case 31 becomes smoother.

  As a modification of the second embodiment, the duct 55 may be a member having only an inclined portion straddling both side portions adjacent to the corner portion of the case 31. Alternatively, this inclined portion may be provided in the case 31.

--Embodiment 3-
FIG. 9 is a side view of Embodiment 3 of the electricity storage module of the present invention.
The power storage module 1 shown in the third embodiment is different from the first embodiment in that fins 56 that are thermally coupled to the cooling structure 50 are provided in the case 31 to increase the cooling area.
The fins 56 may be formed integrally with the cooling plate 52 by molding, or may be formed separately from the cooling plate 52 and fixed to the cooling plate 52 by fastening with a fastening member or the like.

  The fin 56 is provided at a position facing the electric fan 35 so that the air sent from the electric fan 35 directly hits the cooling efficiency. However, the position where the fins 56 are provided is not limited to the above, and may be provided at other positions.

  In the third embodiment, other configurations are the same as those of the first embodiment, and the corresponding members are denoted by the same drawing numbers and the description thereof is omitted.

In the third embodiment, the same effect as that of the first embodiment can be obtained.
Moreover, in Embodiment 3, since the cooling area increases by providing the fin 56, the heat radiation from the battery cell 10 is promoted, and the cooling efficiency can be improved.

  The structure in which the fins 56 of the cooling structure 50 shown in the third embodiment are provided integrally may be combined with the structure in which the duct 55 or the inclined portion shown in the second embodiment or its modification is provided.

  In the said embodiment, the assembled battery 20 illustrated as a structure which fixes the bus-bar 13 which connects each battery cell 10 by fastening with a screw | thread. However, other fixing methods such as joining the bus bar 13 and the battery cell 10 by welding may be used.

  In the said embodiment, it illustrated by the case where a lithium ion secondary battery cell was used as the battery cell 10 which comprises the assembled battery 20. As shown in FIG. However, the power storage module 1 of the present invention can be configured using other secondary battery cells such as a nickel hydride secondary battery cell and a nickel cadmium secondary battery cell. In addition to the secondary battery cell, a lithium ion capacitor can be applied.

  The power storage module 1 shown in the above embodiment is also applied to a power storage device that constitutes a power supply device other than an electric vehicle, such as an uninterruptible power supply device used in a computer system or a server system, or a power supply device used in a private power generation facility. You can also.

In addition, the power storage module of the invention can be variously modified and configured within the scope of the invention. In short, an assembled battery, a cooling structure for cooling a secondary battery cell, and an assembled battery And a fan disposed in a space between the case and one side surface of the case , the fan blows air in the case toward the cooling structure unit side, and between the periphery of the cooling structure unit and the case inner surface and through moving, the fan is moved to the space opposite to the can placed side, further, a fan on the side opposite to the cooling structure portion side along the the opposite side of the casing and arranged side Convection so that the positive and negative external terminals are cooled while moving from the space opposite to the side where the fan is placed to the space where the fan is placed, and then blown again toward the cooling structure. Anything can be used.

DESCRIPTION OF SYMBOLS 1 Power storage module 2 Battery can 3 Battery cover 6 Power generation element 10 Battery cell 11 Positive external terminal 12 Negative external terminal 13 Bus bar 31 Case 33 Piping 35 Electric fan 50 Cooling structure part 51 Cooling medium 52 Cooling plate 53 Thermally conductive sheet 55 Duct 56 fin

Claims (6)

A plurality of two power generation elements having positive and negative electrode plates are accommodated in a battery container, and positive and negative external terminals connected to the positive and negative electrode plates are arranged on one side of the battery container. An assembled battery in which the next battery cell is electrically connected;
A cooling structure that is thermally coupled to the other side facing the one side of each of the secondary battery cells; and
A case housing the assembled battery and the cooling structure;
A fan housed in the case and disposed in a space between the assembled battery and one side surface of the case,
The fan, the air inside the casing, the blows air toward the cooling structure portion side, and through the between the periphery and the inner surface of the case of the cooling structure portion, opposite to the side where the fan is located And moved to a side opposite to the cooling structure side along the side surface of the case opposite to the side where the fan is disposed, and the side where the fan is disposed. characterized in that the to move while cooling the external terminals of the positive and negative electrodes in a space of the fan from a space on the opposite side are arranged side causes convection to blow back toward the said cooling structure portion Power storage module.   2. The power storage module according to claim 1, wherein the cooling structure includes a pipe through which a cooling medium circulates and a cooling plate provided in close contact with an outer periphery of the pipe. .   The power storage module according to claim 2, wherein the cooling structure unit further includes a heat conductive insulating sheet interposed between the cooling plate and the other side surface of each secondary battery cell. A power storage module.   4. The power storage module according to claim 1, wherein each of the secondary battery cells has a pair of large-area side surfaces adjacent to the one side surface on which the positive and negative external terminals are arranged. 5. The secondary battery cell is a prismatic secondary battery cell, and the fan is disposed in a space between an outer side surface and an inner surface of the case among a pair of large area side surfaces of the secondary battery cell on one end side of the assembled battery. In addition, a duct for guiding the air in the case to the fan side is provided in the space.   5. The power storage module according to claim 4, wherein the duct has an air inlet that moves on an inner surface of the case opposite to the cooling structure portion, and an inclined portion at a corner portion that faces the inlet. A power storage module characterized by the above.   6. The power storage module according to claim 1, wherein a cooling fin that is thermally coupled to the cooling structure portion is provided at least between the fan and the cooling structure portion. A power storage module.

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