KR100627312B1 - Secondary Battery Module - Google Patents

Abstract

In order to form a flow of cooling air evenly in the case of a large number of unit cells arranged, the inside of the housing and the housing in which the air inlet is formed on one side and the air outlet is formed on the other side to form a flow of cooling air It includes a plurality of unit cells are stacked and installed, the inlet portion of the housing is divided into both sides at the middle of the arrangement direction of the unit cell is formed so that air is introduced from both sides in the arrangement direction of the unit cell, the discharge portion of the housing A battery module is provided so that air is discharged to both sides with respect to the arrangement direction of each unit cell by dividing into both sides at an intermediate point of the arrangement direction of the unit cells so as to be symmetrical with the unit.

Secondary battery, battery module, cooling, air, flow path, flow direction, bulkhead, unit cell, slope, temperature distribution

Description

Battery Module {Secondary Battery Module}

1 is a perspective view schematically showing an embodiment of a battery module according to the present invention.

2 is a cross-sectional view schematically showing an embodiment of a battery module according to the present invention.

Figure 3 is a perspective view showing the configuration of a battery assembly in an embodiment of a battery module according to the present invention.

4 is a perspective view schematically showing another embodiment of a battery module according to the present invention.

5 is a cross-sectional view schematically showing another embodiment of a battery module according to the present invention.
<Description of the symbols for the main parts of the drawings>
10: housing 11: battery compartment
12: inlet 14: inner guide surface
15, 17: Separator 16: Outlet
18: blower fan 19: tip inlet
20: battery assembly 22: unit cell
30: bulkhead 32: protrusion

The present invention relates to a battery module, and more particularly, to a battery module having a structure in which a flow of cooling air is formed evenly as a battery assembly consisting of a plurality of unit cells, and thus the whole battery assembly can be cooled evenly. It is about.

In general, a secondary battery is a battery that can be repeatedly used because it can be charged and discharged, and is used as a secondary battery composed of one battery cell in portable electronic devices such as mobile phones, notebook computers, cameras, camcorders, and the like. It is used in the form of a large-capacity secondary battery (hereinafter referred to as a "battery module") in which a plurality of battery cells (hereinafter referred to as "unit cells") are combined as a power source for driving a motor such as an automobile (HEV) and an electric vehicle (EV). .

The unit cell, which is a basic element of the battery module, includes an electrode assembly having a separator inserted between an anode plate and a cathode plate, a case in which the electrode assembly is embedded, a cap assembly for sealing the case, and an assembly of the electrode assembly. A positive electrode terminal and a negative electrode terminal electrically connected to the positive electrode plate and the negative electrode plate, respectively.

In the case of a rectangular battery, each unit cell is arranged such that the positive electrode terminal and the negative electrode terminal protruding from the top of the cap assembly are crossed with the positive electrode terminal and the negative electrode terminal of a neighboring unit cell, and between the screwed negative electrode terminal and the positive electrode terminal. Is connected by a nut and formed into a battery module.

One battery module has a configuration in which several to several dozen unit cells are connected, and since each unit cell generates heat severely, an appropriate cooling structure, safety means, a system circuit, and the like must be provided, thereby increasing the overall volume.
This problem of volume increase can be solved by narrowly arranging the intervals between the unit cells constituting the battery module, but such a compact structure is unable to efficiently cool the unit cells.

Therefore, the design of the battery module should have a structure capable of effectively dissipating heat generated from each unit cell as well as minimizing volume. If the heat generated from each unit cell is not effectively released, the temperature of the battery module is increased, and the performance of each unit cell is degraded, resulting in a malfunction of the device to which the battery module is applied.

In particular, in the case of a high output large capacity battery module, such as for HEV (Hybrid Electric Vehicle), EV (Electric Vehicle), heat dissipation is important, and when the size of the battery module is increased, the weight of the battery itself is not only increased but also the battery. There is a problem that the design of the device (especially the vehicle) on which the module is mounted becomes difficult.

Therefore, in the case of a battery module that requires a high output large capacity, it is very necessary to develop a battery module that can improve the heat dissipation characteristics while minimizing the size.

The conventional cooling structure of the battery module is to install a partition to ensure a space for the distribution of cooling air between each unit cell and structurally prevent deformation of the unit cell, the assembly of the unit cell and the partition wall in the housing In addition, the cooling air for controlling the temperature of the unit cell is supplied to the inside of the housing to allow the cooling air to flow through the partition wall, so as to cool the heat generated in each unit cell.

However, in the cooling method of such a battery module, the flow rate of the cooling air circulated to the partition wall between the unit cells is not constant, so there is a disadvantage that the heat dissipation is not uniform because of the temperature difference between the unit cells, due to this problem Another problem occurs that the charging and discharging efficiency of the battery module is lowered.

In addition, in the conventional cooling method of the battery module, when the number of unit cells is more than 20, the total length of the unit cells is formed long, the flow distance of the air increases accordingly, the pressure according to the flow resistance inevitably generated As the loss occurs and moves away from the inlet of the cooling air, the flow rate of the air is not sufficient, and the unit cell is not evenly cooled.

An object of the present invention is to solve the above problems, in order to be able to cool the unit cell evenly even in the case of a large number of unit cells divided into two in the middle direction of the arrangement direction of the unit cell formed in the inlet and outlet It is for providing a battery module.

The battery module proposed by the present invention includes a housing in which an air inlet part (air cooling air) is introduced and an exhaust part in which air is discharged is formed on one side, and a plurality of unit cells stacked and installed inside the housing. And the inlet of the housing is divided into both sides at an intermediate point in the arrangement direction of the unit cell so that air is introduced from both sides, and the outlet of the housing is formed in a symmetrical shape with the inlet of each unit cell. Passed air is separated from the central point and formed to be discharged to both sides.

The battery module of the present invention further includes a plurality of partition walls installed between the unit cells and forming a space (air flow path) through which air passes.

The inlet of the housing may be formed to have an inclination angle of 15 ° or more with respect to the arrangement direction of the unit cells.

Next, a preferred embodiment of the battery module according to the present invention will be described in detail with reference to the drawings.

First, one embodiment of the battery module according to the present invention, as shown in Figs. 1 to 3, one side is open to the inlet 12 through which the cooling air is introduced, the other is the discharge portion 16 through which the cooling air is discharged The housing 10 is opened, and the battery assembly 20 accommodated in the housing 10 is configured to include.

In the battery module of the present invention, as shown in FIG. 3, the battery assembly 20 includes a plurality of unit cells 22 stacked with the partitions 30 interposed therebetween so that air passes between them (air flow path). This structure is formed.

The unit cells 22 and the partition walls 30 are alternately stacked to constitute the battery assembly 20, and are installed inside the housing 10 in the stacked assembly state.

The partition wall 30 may be provided with a plurality of protrusions 32 so as to form a predetermined gap (path for cooling air to flow) between the adjacent unit cells 22.

In addition, the protrusion 32 may be integrally formed on the partition wall 30 or separately formed, and attached to each predetermined place. More simply, the projection 32 may be formed integrally with the partition 30 through embossing, drawing, or the like.

The protrusion 32 may be formed only on one side of the partition wall 30, or may be formed on both sides.

When the protrusions 32 are formed in the partition wall 30 as described above, not only the strength of the partition wall 30 is improved but also a gap (air flow path) exists between the partition wall 30 and the unit cell 22. As a result, the circulation of cooling air is uniform, and effective heat dissipation can be expected.

In the above description, the air is circulated by forming the protrusions 32 in the partition wall 30. However, the present invention is not limited thereto, and a plurality of grooves or holes are formed in the partition wall 30 to provide cooling air. It is also possible to make it into a distribution channel. That is, a groove may be formed on the surface of the partition wall 30 at a predetermined depth in the air distribution direction, and a through hole may be formed so that air flows through the interior of the partition wall 30.

In the housing 10, the battery assembly 20 is arranged to be accommodated by a battery mounting portion 11 provided between the inlet portion 10 and the discharge portion 16, and to minimize the volume of the battery assembly 20. Two housings 10 are disposed adjacent to each other with 15 and 17 interposed therebetween, so that the two inlets 12 and the outlets 16 are opened in a symmetrical direction.

Since the battery mounting unit 11 merely provides an accommodation space for accommodating and fixing the battery assembly 20, any type of battery mounting unit 11 may be adopted as long as it can accommodate and fix the battery assembly 20. Can be.

The pair of inlets 12 open in the symmetrical direction are divided by the separating plate 15 in the interior of the housing 10, so that each of the pair of inflow portions 12 has an air flow path separately.

In addition, each inlet 12 is provided with blowing means such as a blowing fan 18 for sucking outside air and supplying the same. As the blowing means, it is also possible to use various fan devices such as propeller fans, sirocco fans, or air pumps, and in the case of automobiles, it is also possible to use a headwind that is naturally generated while driving, and a blower (e.g., assigned to another system) For example, in automobiles, it is also possible to borrow some of the airflow generated from the condenser fan or radiator fan of the air conditioning system.

Air generated by the blower fan 18 and supplied to the inlet 12 may have a tip inlet 19 for inducing the air to flow in a direction substantially parallel to the arrangement direction of the unit cell 22. It is good to provide in the part 12.

In addition, the portions in which the inflow portions 12 symmetrically extended inside the housing 10 meet each other at the separator plate 15 are provided with the battery mounting portion 11 without cooling air guided by the tip inlet 19. It is preferable to form an inclined surface that forms a substantially "V" shape so as to be turned toward the stored battery assembly 20.

Separation plate 15 is installed in parallel with the unit cell 22 at the point where the inlet portion 12 of the both sides meet each other so that the air flowing through the inlet portion 12 of both sides smoothly without colliding with each other It is guided to change direction toward the unit cell 22.

The separation plate 15 prevents the air flowing in the direction facing from both front end inlets 19 to collide with each other at an intermediate point, and the flow of air is in the arrangement direction of the unit cells 22 of the battery assembly 20. It is diverted to ensure that an effective air flow can be created.

The separation plate 15 may be installed to extend between the unit cells 22, or may be installed to extend only to a position proximate to the unit cell 22.

When the inclined surface of the separator plate 15 disposed between the pair of inflow portions 12 is formed to start from a position at a predetermined interval from the unit cell 22, the inflow portion enters through the tip inlet 19. It is advantageous in that the flow amount of air moving along the wall surface of (12) can be secured in an amount sufficient to pass through the flow path between the unit cells 22 located at the intermediate point.

The pair of discharge parts 16 are also formed to be open in the same symmetrical direction as the inlet part 12, and the air is discharged to both sides by dividing and partitioning the middle points of the unit cells 22 in the array direction.

Accordingly, the separator 17 is installed at an intermediate point where the pair of discharge parts 16 meet, so that air passing through the unit cell 22 is effectively divided and discharged in both sides.

The intermediate point where the pair of inlet part 12 and the outlet part 16 meet is preferably formed as an inclined surface that naturally converts the flow direction of air.

As described above, when the inlet part 12 and the outlet part 16 are formed by dividing the two parts at the intermediate point in the array direction of the unit cell 22, even when the number of the unit cells 22 arranged is greater than 20, The shorter distance is reduced, so that the temperature difference between the unit cell 22 close to the tip inlet 19 and the unit cell 22 far from the tip inlet 19 is reduced to 1/2 compared to the case where the unit cell 22 is composed of one unit cell. It is possible to reduce the temperature deviation between 22.

Inlet 12 in the battery module according to the invention can be implemented in a structure as shown in Figures 4 and 5. In this embodiment, the pair of inflow portions 12 are arranged in an inclined direction with respect to the arrangement direction of the unit cells 22 so that the air flows at an angle.

In the above embodiment, when the air flowing into the tip inlet 19 goes straight toward the unit cell 22, the flow rate of the air is partially uneven. In this embodiment, the tip inlet 19 is arranged in the arrangement direction of the unit cell 22. It is formed so as to be parallel to or to have a negative inclination angle with the array direction of the unit cell 22, it is suppressed that the air entering through the tip inlet 19 to move straight toward some unit cells 22.

The inlet 12 has an outer guide surface 13 which is inclined toward both front end inlets 19 through which air is introduced at the intermediate points in the arrangement direction of the unit cells 22, and at both front end inlets 19. It is formed by the inner guide surface 14 which extends inclined to the battery mounting part 11 located in the nearest side.

The outer guide face 13 and the inner guide face 14 are installed in a state substantially parallel to each other.

The outer guide surfaces 13 are arranged in pairs to form an approximately "V" shape around the separator plate 15.

The outer guide surface 13 is formed as an inclined surface that is closer to the unit cell 22 as it moves toward the intermediate point away from the tip inlet 19 along the arrangement direction of the unit cell 22.

At the point where the pair of outer guide surfaces 13 meet each other, a separator 15 is installed in parallel with the unit cell 22.

The separating plate 15 prevents the air introduced from both front end inlets 19 from colliding with each other at an intermediate point so that an effective air flow is achieved.

The separating plates 15 and 17 may be installed to extend to the inside of the unit cell 22, or may be installed to extend only to a position close to the unit cell 22.

Points where the pair of outer guide surfaces 13 meet each other in the separating plates 15 and 17 are disposed at predetermined intervals from the unit cell 22, and are introduced from the tip inlet 19 so that The flow rate of the air moving along the outer guide surface 13 can be secured in an amount sufficient to pass through the flow path between the unit cells 22 located at the intermediate point.

As described above, when the outer guide surface 13 is inclined toward the intermediate point from both sides with respect to the arrangement direction of the unit cell 22, a pair of outer guide surfaces in which air introduced into the both front end inlets 19 are inclined. It is guided to (13) and flows to the vicinity of the intermediate point of the unit cells (22). In this case, since the outer guide surface 13 is formed as an inclined surface approaching toward the unit cell 22 as it moves away from the tip inlet 19 and approaches the intermediate point, the flow cross-sectional area of the air is far from the tip inlet 19. The more it gets, the narrower it becomes, so the air velocity becomes faster.

Therefore, the air introduced through the tip inlet 19 is cooled while passing through the unit cells 22 at a constant flow rate (flow rate), thereby maintaining the cooling at a uniform and appropriate temperature over the entire region of the battery assembly 20. It is possible to do That is, all of the air introduced through the tip inlet 19 does not move straight toward the unit cell 22 and is directly guided to the outer guide face 13 or guided to the outer guide face 13. While interfering with each other, the direction is changed by 90 ° to move toward each unit cell 22. In this process, the same flow rate is evenly distributed and flows in and out of each unit cell 22 according to the hydrodynamic principle. One temperature control is possible.

In the above, the flow passages (distribution cross-sectional area) through which air formed through the partition walls 30 pass between the unit cells 22 are all configured in the same manner.

The inlet part 12 of the housing 10 is formed to have an inclination angle θ of about 15 ° or more with respect to the arrangement direction of the unit cell 22. That is, the outer guide surface 13 and the inner guide surface 14 are formed to have an inclination angle θ of about 15 ° or more with respect to the arrangement direction of the unit cells 22 embedded in the battery mounting unit 11.

When the inclination angle θ of the outer guide surface 13 is smaller than 15 °, the decrease in pressure that appears toward the intermediate point away from the tip inlet 19 is too small and the increase in flow rate is small. The flow rate of air passing through the flow path between the unit cells 22 located far from the front end inlet 19 is less than the flow rate of air passing through the flow path between the unit cells 22 located closer to (19). The air of the same flow rate cannot be distributed, a temperature deviation occurs between the unit cells 22, and an even temperature distribution cannot be obtained over the entire area of the battery assembly 20.

Therefore, the inclination angle θ of the inlet portion 12 (outer guide surface 13) of the housing 10 is preferably set to be about 15 ° or more with respect to the arrangement direction of the unit cell 22. Preferably, the inclination angle θ is set within a range of approximately 15 to 45 degrees. In this case, when the inclination angle θ of the outer guide surface 13 is set to be greater than 45 °, the increase in flow velocity is too large, so that the flow path between the unit cells 22 located near the tip inlet 19 is increased. The flow rate of the air passing through the flow path between the unit cells 22 located at the intermediate point farther from the distal inlet port 19 than the flow rate of air passing therebetween is largely not distributed through the same amount of air, and thus between each unit cells 22. Since a temperature deviation occurs, an even temperature distribution cannot be obtained over the entire region of the battery assembly 20.

Also in the above-described other embodiments, the present invention can be implemented in the same configuration as the above-described embodiment except for the above-described configuration, and thus a detailed description thereof will be omitted.

The battery module according to the present invention configured as described above is a device for operating by using a motor such as a HEV (hybrid electric vehicle), an EV (electric vehicle), a wireless cleaner, an electric bicycle, an electric scooter, etc. It can be used as an energy source (for driving a motor), and besides, it can be used for various applications requiring high power / large capacity.

In the above, a preferred embodiment of the battery module according to the present invention has been described, but the present invention is not limited thereto, and various modifications can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. This also belongs to the scope of the present invention.

According to the battery module according to the present invention made as described above, since the air distribution structure of the housing is improved, air of a constant flow rate is circulated through the distribution path between the unit cells, thereby achieving an even temperature distribution over the entire area of the battery assembly. Thus, the cooling efficiency can be maximized. Therefore, it is possible to further improve the charging and discharging efficiency of the battery module.

In addition, according to the battery module according to the present invention, even when the number of unit cells arranged is divided into a housing at an intermediate point, the partitioned area is provided with a dedicated air flow path by the inlet and outlet, respectively, There is no accumulation of air in the interior, minimizes the flow rate difference due to pressure loss, and provides a battery module that maximizes cooling efficiency.

Claims (6)

And a battery assembly in which air inlet and air outlet are paired and opened in a symmetrical direction, and a battery assembly stacked and installed as a battery mounting part in the housing, wherein the inlet and the outlet of the housing The battery module is configured to be divided into two sides by a separator plate in the middle direction of the arrangement direction of the unit cell forming the battery assembly to form a respective air flow path. The method according to claim 1, A battery module further comprising a plurality of partition walls are formed between the unit cells to form a space through which air passes. The method according to claim 1 or 2, The inlet of the housing is a front end inlet is attached to the battery module is configured to guide the air flowing into the inlet in the direction parallel to the arrangement direction of the unit cell. delete delete The method according to claim 3, The inlet of the housing is a battery module is configured to be formed of the outer guide name and the inner guide surface inclined in the range of 15 to 45 degrees with respect to the arrangement direction of the unit cell, respectively.

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