KR20060037603A - 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, respectively, 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 two 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.

The present invention relates to a battery module, and more particularly, to a battery module which is configured by connecting a plurality of unit cells and forming a flow of cooling air so as to cool the whole.

In general, a secondary battery is a battery that can be repeatedly used because it can be charged and discharged. A secondary battery composed of one battery cell is mainly used for portable small electronic devices such as mobile phones, notebook computers, cameras, and camcorders. As a power source for driving a motor such as a hybrid electric vehicle (HEV) and an electric vehicle (EV), a large capacity secondary battery (hereinafter referred to as a "battery module") formed by connecting a plurality of battery cells (hereinafter referred to as "unit cells") is used. Mainly used.

Each unit cell constituting the battery module includes an electrode assembly formed by inserting a separator, which is an insulator, between the positive electrode plate and the negative electrode plate, a case having a space in which the electrode assembly is built, and a cap coupled to and sealed to the case. And a positive electrode terminal and a negative electrode terminal protruding from the cap assembly and electrically connected to the positive electrode plate and the negative electrode plate of the electrode assembly, respectively.

In the case of a rectangular battery, each unit cell is arranged in such a manner that each of the unit cells is cross-aligned so that the positive electrode terminal and the negative electrode terminal protruding from the top of the cap assembly alternate with the positive terminal and the negative terminal of the neighboring unit cell. A battery module is constructed by connecting a conductor using a nut between the positive electrode terminals.

Since the battery module constitutes one battery module by connecting several to several tens of unit cells, a cooling structure, safety means, system circuit, and the like, which are configured to easily discharge heat generated from each unit battery, are provided. There is a problem that the volume is large. In order to solve this problem, a method of reducing the size by reducing the interval of unit cells constituting the battery module is used, but in this case, another problem that it is difficult to dissipate heat generated from the unit cells occurs.

Therefore, in designing a battery module, the volume should be minimized, and the heat generated from each unit cell should be easily discharged. Failure to effectively dissipate heat generated in each unit cell results in an increase in temperature of the battery module, deterioration in performance of each unit cell, and consequently 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.

In addition, the conventional battery module is provided with a partition wall in order to secure 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, the unit The cooling air for controlling the temperature of the battery is supplied to the inside of the housing to distribute the cooling air through the partition wall, thereby cooling the heat generated in each unit cell.

However, in the conventional cooling method of the battery module, the flow rate of the cooling air circulated to the partition walls between the unit cells is not constant, so that a temperature difference occurs between the unit cells, and heat generated from each unit cell is not evenly radiated. . Therefore, there is a problem that the charge and discharge 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, and the flow distance of air increases accordingly, and 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.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and inlet and outlet portions are formed by dividing both sides at an intermediate point in the arrangement direction of the unit cells so that even when the number of unit cells is large, the unit cells can be cooled evenly. It is for providing a battery module.

The battery module proposed by the present invention includes a housing in which an air inlet part is formed to which air (cooling air) is introduced, and a discharge part in which air is discharged to one side, and a plurality of unit cells stacked in the housing. And the inlet portion 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 portion of the housing is formed in a symmetrical shape with the inlet portion. 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 passage) through which air passes.

In the above inlet portion of the housing may be formed to have an inclination angle of 15 ° or more with respect to the arrangement direction of the unit cell.

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

First, as shown in FIGS. 1 to 3, one embodiment of the battery module according to the present invention has an inlet 12 through which air is introduced and an outlet 14 through which air is discharged. And a plurality of unit cells 22 stacked and installed in the housing 10.

In addition, as shown in FIG. 3, the battery module according to the present invention further includes a plurality of partition walls 30 formed between the unit cells 22 and forming a space (air flow path) through which air passes. Include.

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

It is also possible to form a plurality of protrusions 32 in the partition wall 30 so as to maintain the unit cells 22 stacked therein and a predetermined gap (passage for allowing cooling air to flow).

The protrusion 32 may be formed as a separate member and attached to the partition wall 30, or may be integrally formed with the partition wall 30. The protrusion 32 may be formed integrally with the partition 30 by 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 air for cooling flows through this gap, heat dissipation is effectively performed.

In the above description, the air is circulated by forming the projections 32 in the partition 30. However, the present invention is not limited thereto, and the air is formed by forming a plurality of grooves or holes in the partition 30. It is also possible to form a flow path for circulation. That is, a groove may be formed on the surface of the partition wall 30 at a predetermined depth along the flow direction of the air, and may form a through hole along the flow direction of the air through the inside of the partition wall 30. Do.

As shown in FIGS. 1 and 2, the housing 10 includes a battery mounting part 11 having a battery assembly 20 formed by alternately stacking the unit cells 22 and the partition walls 30, and the battery. A pair of inlets 12 into which air for controlling the temperature of each unit cell 22 installed and built in connection with one side of the mounting unit 11 is introduced, and the battery on the opposite side of the inlets 12. It is connected to the other side of the mounting portion 11 is installed and comprises a pair of discharge portion 16 is discharged air passing through each unit cell 22.

The battery mounting part 11 forms a receiving space for accommodating and fixing the battery assembly 20, and the specific structure of the battery mounting part 11 is particularly provided that the battery assembly 20 can be fixed and supported by the battery assembly 20. It is not limited.

The pair of inlets 12 are divided into both sides at an intermediate point in the arrangement direction of the unit cell 22 so that air is introduced from both sides.

Each inlet 12 is provided with blowing means such as a blower fan 18 for forcibly supplying air. As the blowing means, it is also possible to use various fan devices such as propeller fans and sirocco fans or air pumps, and in the case of automobiles, it is also possible to use forced convection generated during driving and blowers installed in other systems (for example, For example, in automobiles, it is possible to use a condenser fan or a radiator fan of an air conditioning system together.

The air flowing into the inlet 12 by the blowing means (blowing fan 18) is provided in each of the inlets 12 so that the air is introduced in a direction substantially parallel to the arrangement direction of the unit cell 22. A tip inlet 19 is formed.

The portion where the two inlets 12 meet each other is approximately " V " so that the air flowing from the tip inlet 19 effectively shifts the moving direction toward the unit cell 22 built in the battery mounting unit 11. It is formed into a shape.

In addition, the separation plate 15 is installed in parallel with the unit cell 22 toward the unit cell 22 from the point where the inflow portions 12 of the both sides meet each other, so that the air introduced from both sides does not collide with each other smoothly. Since the direction of movement is guided toward the unit cell 22 is preferable.

If the separation plate 15 is not provided in the above, as the air flowing from both front end inlets 19 meet each other at an intermediate point and collide with each other, irregularity is increased in the air flow, thereby preventing effective air flow control.

The separator 15 may be extended to the inside of the unit cell 22, and may be installed to extend only to a position proximate to the unit cell 22.

The point where the pair of inlets 12, on which the separator 15 is installed, meets each other is configured to be positioned at a predetermined interval from the unit cell 22. The flow rate of air moving along the wall surface of (12) is preferable because it can be secured enough to pass through the flow path between the unit cells 22 located at the intermediate point.

The pair of discharge parts 16 are formed to be symmetrical with the inlet part 12, and are formed to be discharged to both sides by dividing at an intermediate point in the arrangement direction of the unit cell 22.

In the intermediate point where the pair of discharge parts 16 meet, it is preferable to install the separator 17 so that the air passing through the unit cell 22 is effectively divided into both sides and discharged.

The intermediate point where the pair of inlet part 12 and the outlet part 16 meet is preferably formed in a curved surface so that the movement direction of the air can be naturally converted.

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 arrangement direction of the unit cell 22, even when the number of the unit cells 22 arranged is larger than 20, The distance to be traveled is shortened 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 constitutes one, and the unit It is possible to reduce the temperature deviation between the cells 22.

In another embodiment of the battery module according to the present invention, as shown in FIGS. 4 and 5, the air flows in a direction inclined with respect to the arrangement direction of the unit cells 22, respectively. Form.

The tip inlet 19 is formed in parallel with the arrangement direction of the unit cell 22, or formed to have a negative inclination angle with the arrangement direction of the unit cell 22 air introduced into the tip inlet 19 Is preferable because it can prevent the straight movement toward the unit cell 22. Herein, when the air introduced into the tip inlet 19 goes straight toward the unit cell 22, a problem arises in that the flow rate of the air is partially uneven.

The inlet 12 meets at an intermediate point in the arrangement direction of the unit cell 22 and is inclined (inclined with the arrangement direction of the unit cell 22) to both front end inlets 19 through which air is introduced. And a guide surface 13 and an inner guide surface 14 extending inclined from the battery mounting portion 11 positioned closest to both of the tip inlets 19.

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

The pair of outer guide surfaces 13 are provided to form a substantially "V" shape.

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

The separator 15 is provided in parallel with the unit cell 22 from the point where the pair of outer guide surfaces 13 meet each other.

If the separation plate 15 is not provided in the above, as the air flowing from both front end inlets 19 meet each other at an intermediate point and collide with each other, irregularity is increased in the air flow, thereby preventing effective air flow control.

The separator 15 may be extended to the inside of the unit cell 22, and may be installed to extend only to a position proximate to the unit cell 22.

The point where the pair of outer guide surfaces 13 on which the separation plate 15 is installed meets each other is disposed so as to be positioned at a predetermined interval from the unit cell 22. It is preferable because the flow rate of the air moving along the guide surface 13 can be secured enough 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 installed to be inclined from both sides toward the intermediate point with respect to the arrangement direction of the unit cells 22, a pair of outer guide surfaces in which air introduced into the both front end inlets 19 are inclined ( 13 flows along the outer guide surface 13 and flows near the midpoint of the unit cells 22 arranged along the outer guide surface 13. At this time, since the outer guide surface 13 is formed as an inclined surface approaching the unit cell 22 toward the intermediate point away from the tip inlet 19, the cross-sectional area of air is far from the tip inlet 19 The more it decreases, the faster the air flow rate. In other words, according to the continuous equation of hydrodynamics, the flow velocity of the fluid is inversely proportional to the flow cross-sectional area, so that the flow velocity becomes faster when the flow cross-sectional area decreases. Bernoulli's theorem also shows that as the flow cross section decreases, the flow rate increases but the pressure decreases.

Therefore, the air introduced through the tip inlet 19 passes through the unit cells 22 at a constant flow rate (flow rate) according to the hydrodynamic principle as described above, and is generated in each unit cell 22. It is possible to temperature control (cool) the heat evenly, and to maintain a uniform and appropriate temperature over the entire area of the battery assembly 20. That is, all of the air introduced through the tip inlet 19 does not move straight toward the unit cell 22 and directly collides with the outer guide surface 13 or collides with the outer guide surface 13 to reflect the air. In this process, the flow direction is changed by 90 ° to move toward each unit cell 22. In this process, the same flow rate is evenly distributed throughout the unit cell 22 according to the hydrodynamic principle. As a result, uniform temperature control is possible throughout.

In the above, the flow paths (flow cross-sectional area) through which air formed through the partition walls 30 pass between the unit cells 22 are configured to be the same.

The inlet 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 portion 11.

When the inclination angle θ of the outer guide surface 13 is smaller than 15 °, the decrease in pressure that appears as the distance from the tip inlet 19 toward the intermediate point 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 near the side (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, it is preferable to set the inclination angle θ of the inlet portion 12 (outer guide surface 13) of the housing 10 to be approximately 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 the flow rate is too large, so that it passes through the flow path between the unit cells 22 located near the tip inlet 19. Since the flow rate of the air passing through the flow path between the unit cells 22 located at the intermediate point farther from the front end inlet 19 is higher than the flow rate of the air, the air having the same flow rate cannot be distributed as a whole. The temperature deviation between the two occurs, and it becomes impossible to obtain an even temperature distribution over the entire area 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 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, by improving the air flow structure of the housing to distribute the air of a constant flow rate to the flow path between each unit cell, it is to achieve an even temperature distribution over the entire area of the battery assembly It is possible to maximize the cooling efficiency. 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 formed by dividing the inlet and outlet of the housing into the intermediate point both sides, it is possible to minimize the flow rate difference due to pressure loss, cooling It is possible to maximize efficiency.

Claims (6)

It includes a housing in which the inlet is formed in which air is introduced and the discharge portion in which the air is discharged, and a plurality of unit cells are stacked and installed inside the housing, The inlet portion of the housing is divided into both sides at the middle point of the arrangement direction of the unit cell so that air is introduced from each side, The discharge part of the housing is formed in a symmetrical shape with the inlet and the battery module is formed so that the air passing between each unit cell is separated from the central point and discharged to both sides. The method according to claim 1, The battery module further comprises a plurality of partitions provided between the unit cells and forming a space through which air passes. The method according to claim 1 or 2, The housing may include a battery mounting unit in which a battery assembly in which the unit cells and the partition walls are alternately stacked is installed, and a pair of air introduced therein for controlling the temperature of each unit battery installed and connected to one side of the battery mounting unit. An inlet of a pair, and a pair of outlets connected to the other side of the battery mounting unit on the opposite side of the inlet, through which air passed between the unit cells is discharged; And a battery inlet formed at each inlet so that air introduced into the inlet is introduced in a direction parallel to an arrangement direction of a unit cell. The method according to claim 3, The portion where both inlets meet each other is formed in a "V" shape so that the air flowing from the tip inlet effectively shifts the moving direction toward the unit battery embedded in the battery compartment. A battery module for installing a separator plate parallel to the unit cell toward the unit cell from the point where the inlets of both sides meet each other. The method according to claim 3, A battery module for installing a separator so that the air passing through the unit cell is effectively divided into both sides and discharged at the intermediate point where the pair of discharge parts meet. The method according to claim 3, The pair of inflow portions are formed so that air flows in the inclined direction in a range of 15 to 45 degrees with respect to the arrangement direction of the unit cells, The inlet is formed in the battery module to form an outer guide surface with an inclined surface closer to the unit cell toward the intermediate point away from the tip inlet in the arrangement direction of the unit cell.

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