KR100993127B1 - Middle and Large-Sized Battery Pack of Excellent Cooling Efficiency - Google Patents

Abstract

The present invention provides a medium-large battery pack, comprising: a battery module assembly in which a plurality of battery modules in which a coolant flow path is vertically arranged to be in contact with each other in a lateral direction; A pair of side support members surrounding each of the outermost battery modules in the battery module assembly to maintain the arrangement; At least one connection member coupling the side support members to each other; A base plate on which the battery module assembly is mounted; And a pack housing mounted to surround an outer surface of the battery module assembly, and the refrigerant for cooling the battery module is introduced through a refrigerant inlet located at an upper side of one side of the battery module assembly, and proceeds in the arrangement direction of the battery module. While passing through each battery module vertically, and provides a medium-large battery pack consisting of a structure that is discharged through the refrigerant discharge port located in the lower side of the battery module assembly in the refrigerant inlet direction.

Description

Middle and Large-Sized Battery Pack of Excellent Cooling Efficiency

1 is a schematic perspective view of a medium-large battery pack according to an embodiment of the present invention;

2 is a perspective view of a structure excluding a pack housing in the medium-large battery pack of FIG. 1;

3 is an enlarged schematic view of a portion where the Y-type side reinforcement member is mounted in the medium-large battery pack of FIG. 2;

4 is an enlarged partial schematic view of a right portion of the medium-large battery pack of FIG. 3;

5 is a schematic cross-sectional view showing a medium-large battery pack having a structure in which a bead is not formed near a refrigerant inlet port according to another embodiment of the present invention;

6 is a schematic cross-sectional view showing a medium-large battery pack having a structure in which the depth of the beads sequentially decreases toward the refrigerant inlet in accordance with another embodiment of the present invention.

The present invention relates to a cooling system for a medium-large battery pack, and more particularly, a battery module assembly in which a coolant flow path is vertically formed, a side support member and a connection member mounted to the battery module assembly to maintain the arrangement state; And a base plate on which the battery module assembly is mounted, and the pack housing. The refrigerant for cooling the battery module is introduced through a refrigerant inlet located at an upper side of one side of the battery module assembly, and proceeds in an arrangement direction of the battery module. While passing through each battery module vertically, and relates to a medium-large battery pack that is configured to be discharged through the refrigerant outlet located on the lower side of the battery module assembly in the refrigerant inlet direction.

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. Secondary batteries are also attracting attention as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are proposed as a way to solve air pollution in conventional gasoline and diesel vehicles that use fossil fuels. .

One or two or four battery cells are used for small mobile devices, whereas medium and large battery modules, which are electrically connected to a plurality of battery cells, are used in medium and large devices such as automobiles due to the necessity of high output capacity.

Since the medium-large battery module is preferably manufactured in a small size and weight, the rectangular battery, the pouch-type battery, etc., which can be charged with high integration and have a small weight to capacity, are mainly used as battery cells of the medium-large battery module. In particular, a pouch-type battery using an aluminum laminate sheet or the like as an exterior member has attracted much attention in recent years due to its advantages such as low weight, low manufacturing cost, and easy deformation.

In order for the medium-large battery module to provide the output and capacity required in a predetermined device or device, a plurality of battery cells must be electrically connected in series and be able to maintain a stable structure against external force.

In addition, since the battery cells constituting the medium-large battery module is composed of a secondary battery capable of charging and discharging, such a high output large capacity secondary battery generates a large amount of heat during the charging and discharging process. If this is not effectively removed, thermal buildup occurs and consequently accelerates the deterioration of the unit cell, and in some cases there is a risk of fire or explosion. Therefore, a vehicle battery pack that is a high output large capacity battery requires a cooling system for cooling the battery cells embedded therein.

In this regard, some prior art proposes a medium-large battery module having a structure for improving the cooling efficiency. For example, Japanese Patent No. 3355958 describes a medium / large battery module having a structure in which a plurality of battery cells are stacked in a limited space such as a vehicle. In order to prevent the cooling efficiency from being lowered when passing through the stacked battery groups continuously, protrusions forming the coolant flow path are formed on the outer surface of the battery cell, and the stacked battery groups are introduced after the coolant flows between the battery groups. It proposes a structure for cooling the battery cells while passing through. In addition, in the above patent, the battery cell is an alkaline battery such as a nickel-hydrogen secondary battery and the like, so that the outer shape must be formed to have a high mechanical rigidity in itself, so that the plates are placed on both sides in a state in which a plurality of battery cells are overlapped. The band is fixed in a medium-large battery module.

Therefore, there is an effect of improving the cooling efficiency, but due to the external configuration to give a high mechanical rigidity, there is a problem that the volume and weight are greatly increased.

In addition, in the medium-large battery pack composed of a plurality of battery cells, degradation of the performance of some battery cells will result in degradation of the performance of the entire battery pack. Since one of the main causes of such performance nonuniformity is due to cooling nonuniformity between battery cells, a structure capable of securing cooling uniformity during the flow of the refrigerant is required.

Therefore, since the efficiency of cooling varies greatly according to the flow path of the refrigerant in the battery pack, a technology for a medium-large battery pack that can improve cooling efficiency by preventing the refrigerant from escaping with a more compact and stable structure is disclosed. There is a high need.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

Specifically, an object of the present invention is to simplify the assembling process, to have a compact and stable structure, to uniformize the flow rate of the refrigerant flowing in the flow path between the battery cells, and to uniform the heat generated during charging and discharging of the battery cells. It is to provide a medium-large battery pack with high cooling efficiency that can be effectively removed by the flow of a refrigerant.

Medium and large battery packs according to the present invention for achieving the above object, the battery module assembly arranged to be in contact with each other in the lateral direction of the plurality of battery modules in which the coolant flow path is formed vertically; A pair of side support members surrounding each of the outermost battery modules in the battery module assembly to maintain the arrangement; At least one connection member coupling the side support members to each other; A base plate on which the battery module assembly is mounted; And a pack housing mounted to surround an outer surface of the battery module assembly, wherein the refrigerant for cooling the battery module is introduced through a refrigerant inlet located at an upper side of the battery module assembly, and proceeds in an arrangement direction of the battery module. While passing through each battery module vertically, it is made of a structure that is discharged through the refrigerant outlet located on the lower side of the battery module assembly in the refrigerant inlet direction.

That is, in the medium-large battery pack according to the present invention, a plurality of battery modules are stacked in a longitudinal direction or a horizontal direction to form a battery module assembly. The battery module assembly is mounted on a base plate, and both sides are surrounded by side support members. Since the battery module assembly is fixed by a connection member connected to the side support members and a pack housing surrounding the battery module outer surface, the assembly process is simple and has a compact and stable structure as a whole.

A battery module mounted in a medium-large battery pack having such a structure is generally manufactured by stacking a plurality of battery cells with high density, and stacking adjacent battery cells at regular intervals to remove heat generated during charging and discharging. do. For example, the battery cells themselves may be sequentially stacked without a separate member at predetermined intervals, or in the case of battery cells having low mechanical rigidity, one or more combinations may be embedded in a cartridge or the like, and a plurality of such cartridges may be stacked. The battery module can be configured. A coolant flow path is formed between the battery cells or the battery modules so as to effectively remove heat accumulated between the stacked battery cells or the battery modules.

In one preferred embodiment, the connecting member is composed of a pair of frames for pressing the upper front and rear of the battery module assembly, respectively, the frame is the inner surface of the pack housing to induce the flow of refrigerant toward the upper end of the battery module It may be made of a structure that is in close contact with.

That is, the connection member consisting of a pair of frame structure for mutually coupling the side support members located on both sides of the battery module assembly is pressed against the inner surface of the pack housing and at the same time pressing the upper front and rear of the battery module assembly, respectively In addition, the refrigerant flowing into the upper end of the battery module assembly in the width direction of the battery module assembly may be guided through the respective battery modules vertically downward and discharged to the bottom of the pack housing in the refrigerant flow direction.

The connecting member of the structure serves to connect the side support members to each other to couple, and to prevent the refrigerant from escaping to the side of the battery module and to guide the flow of the refrigerant in the vertical lower direction of the battery module. Furthermore, since one member performs two roles at the same time, the number of parts required for manufacturing a battery pack and the number of manufacturing processes of the battery pack can be reduced, thereby ultimately greatly reducing the manufacturing cost of the medium-large battery pack. .

The front and rear of the battery module assembly is a position set with the refrigerant inlet and the refrigerant outlet as the side. Therefore, such a position may be changed to a position on the left and right sides according to a setting criterion, and means a position acting to fix the battery module assembly in which a plurality of battery modules are arranged while being in continuous contact.

In the present specification, the coolant inlet port and the coolant outlet port are flow spaces through which coolant can be introduced and discharged to effectively cool the generation of heat due to charging and discharging of battery cells, and means a flow space formed at the top or bottom of the pack housing, respectively. .

In the above, the refrigerant inlet is defined as being located at the upper end of the one side of the battery module assembly and the refrigerant outlet is located at the lower side of the battery module assembly in the direction of the refrigerant inlet, the structure opposite to that of course, this structure is also the present invention It should be construed as being included in the category of.

On the other hand, if the cross-sectional area of the coolant inlet is greater than or equal to the cross-sectional area of the coolant outlet, the flow rate tends to flow into the flow path between the battery modules near the inlet, and the flow rate decreases much in the flow path between the battery modules far from the inlet. Uniform cooling between the battery modules becomes difficult.

Therefore, as another preferred example of the present invention, the vertical cross-sectional area of the refrigerant inlet may be made smaller than the vertical cross-sectional area of the refrigerant outlet. This structure can make the flow rate of the refrigerant flowing in the flow path between the battery cells uniform, as compared with the case where the vertical cross-sectional area of the conventional refrigerant inlet port is larger than or equal to the vertical cross-sectional area of the refrigerant outlet port, Since the generated heat can be effectively removed by the flow of the uniform refrigerant, the cooling efficiency can be increased and the performance of the battery can be greatly improved.

Preferably, the vertical cross-sectional area of the refrigerant inlet may be formed to have a size of 30 to 90% based on the vertical cross-sectional area of the refrigerant outlet. If the vertical cross-sectional area of the refrigerant inlet is too small, there is a problem that the energy consumption for the flow of the refrigerant is too large, on the contrary, if it is too large, uniform distribution between the battery modules of the refrigerant flow rate as described above may be difficult, which is not preferable. .

The pack housing has a structure in which a length corresponding to the arrangement direction of the battery module is relatively longer than a length corresponding to the width direction of the battery module. Therefore, the refrigerant introduced from the refrigerant inlet is formed between the top surfaces of the battery modules and the pack housing. After passing through the long refrigerant flow space vertically through each battery module has a structure that is discharged to the refrigerant outlet.

In some cases, the upper surface of the pack housing has a structure in which a plurality of beads having a large width-to-width concave-convex shape are formed in the pack housing to exhibit excellent durability or structural stability against external forces such as distortion and vibration. Can be.

Such beads may be formed in an indented bead having a structure indented into the pack housing, or a protruding bead structure protruding outward.

In this case, the indented bead may have a structure in which the depth of indentation of the bead decreases in the direction of the coolant inlet so as to minimize the influence on the coolant flow into the battery module assembly.

That is, since the influence of the flow of the refrigerant from the bead is the biggest near the refrigerant inlet, the depth of the beads near the refrigerant inlet is relatively small, and as the distance from the refrigerant inlet increases, the depth of the beads is sequentially increased. . Therefore, the effect of the beads on the flow of the refrigerant can be minimized by using a structure in which the depth of the beads on the refrigerant inlet side is made low.

As another example, the protruding bead may have a structure in which the protruding height of the bead reduces its height toward the refrigerant inlet so as to minimize the influence on the refrigerant flow into the battery module assembly. The effect of this structure is approximately similar to that of the indented bead, so a detailed description thereof is omitted.

These structures, in order to further increase the flow distribution uniformity between the battery modules while minimizing the structural stability of the pack housing, reduce the depth or height of the bead toward the refrigerant inlet, and sequentially in a direction away from the refrigerant inlet. It includes all of the structures that increase the depth or height of the beads, or sequentially increase to a predetermined depth or height, and then maintain the original bead depth or height from the next specific bead. In this case, the number of beads varying in depth or height may be appropriately determined in consideration of the degree of decrease in the structural strength of the pack housing according to the bead depth adjustment.

As another preferred example of the bead structure that does not interfere with the flow of the refrigerant, the bead is not formed at a predetermined distance from the refrigerant inlet to minimize the influence on the refrigerant flow into the battery module assembly. Can be done. Specifically, the beads may be formed parallel to the width direction of the battery module, and may have a structure in which no beads are formed at a portion adjacent to the refrigerant inlet.

That is, since the influence of the flow of the refrigerant from the bead is the largest in the vicinity of the refrigerant inlet, if the beads are formed from a predetermined distance from the refrigerant inlet, it is possible to minimize the effect of the beads on the flow of the refrigerant.

Preferably, the suction fan may further include a suction fan so that the coolant introduced from the coolant inlet passes through the battery module and quickly and smoothly moves to the coolant outlet to be discharged to the outside of the battery pack. In this structure, due to the flow driving force of the refrigerant generated by the suction fan, the refrigerant introduced through the narrow inlet sufficiently reaches the battery module far from the inlet at a high flow rate, so that the flow rate of the refrigerant is relatively uniform under the same conditions. The distribution effect is exerted.

The base plate may have a curved structure to support only lower ends of both sides of the battery module assembly. Therefore, a coolant flow path is formed between the upper surface of the base plate and the lower surface of the battery module assembly. It has a structure that is discharged to the refrigerant discharge port along the refrigerant passage.

As used herein, the term "battery module" refers to a structure of a battery system capable of mechanically fastening two or more charge / discharge battery cells and electrically connecting them at the same time to provide a high output large capacity electricity. This includes all of the cases in which one device or a part of a large device is configured. For example, it is also possible to configure a large battery module in which a plurality of small battery modules are connected.

Accordingly, the battery module may have a structure in which a plurality of plate-shaped battery cells capable of charging and discharging or unit modules containing a plurality of the plate-shaped battery cells are mounted in a module case. It means a rectangular parallelepiped shape having a relatively long length.

The battery cell is, as a secondary battery, a nickel hydride secondary battery, a lithium secondary battery, and the like, and the like. Among them, a lithium secondary battery having a high energy density and a high discharge voltage is particularly preferable. As the charge / discharge unit cell constituting the battery module, a rectangular battery and a pouch-type battery are preferable in terms of shape, and a pouch-type battery having a low manufacturing cost and a low weight is more preferable.

The medium-large battery pack according to the present invention includes a plurality of battery cells in order to achieve high output and large capacity, and thus is particularly preferably used for power sources such as electric vehicles and hybrid electric vehicles in which high heat generated during charging and discharging is seriously raised in terms of safety. However, the scope of application is not limited to these.

Hereinafter, although described with reference to the drawings according to an embodiment of the present invention, this is for easier understanding of the present invention, the scope of the present invention is not limited thereto.

1 is a perspective view of a medium-large battery pack according to an exemplary embodiment of the present invention, and FIG. 2 is a perspective view of a structure excluding a pack housing of the medium-large battery pack of FIG. 1.

Referring to these drawings, the medium-large battery pack 100 includes a battery module 110 in which a plurality of unit modules are mounted, a base plate 120 on which the battery modules 110 are mounted, and a pair of side support members 130. ), The connecting member 140, and the pack housing 170.

The battery modules 110 are stacked vertically on the base plate 120, and a plurality of through holes 116 are formed on the upper surface thereof to allow the refrigerant to penetrate the battery module 110 vertically. The side support member 130 is in close contact with the outer surfaces of the outermost battery modules 112 and 114 and is coupled to the base plate 120. In some cases, the side support member 130 may be a component itself constituting a medium-large battery pack, rather than a separate plate-shaped structure. For example, in the drawings only one side support member is shown to be a plate-like structure.

The side support member 130 is positioned so that the lower end 135 protruding from the end thereof is in contact with the mounting portion 122 of the base plate 120, and the rectangular fastening is formed on the base plate 120 Using a circular fastening groove 136 formed in the groove (not shown) and the lower extension 135 of the side support member 130, it is coupled to the female screw / male screw fastening structure.

On the upper surface of the stack of battery modules 110, a pair of connecting members 140 are coupled to the upper ends of both sides of the side support member 130 while pressing the upper edges of both sides of the battery module stack, that is, the battery module assembly. have.

The connection member 140, in particular, consists of a pair of frames for pressing the top of the front and rear of the battery module 110 assembly, respectively. The frame is in close contact with the inner surface of the pack housing 170 so as to guide the flow of the coolant toward the upper end of the battery module 110, the refrigerant for cooling the battery modules 110 is the side of the battery module 110 assembly Block it from exiting.

Refrigerant flows into the upper side (A) of the front side of the battery module 110 assembly, and then moves in the longitudinal direction (L) of the battery module 110 assembly to penetrate each battery module vertically downward and then to the front side of the battery module assembly. It is discharged to the bottom (B).

An extension (not shown) of the pack housing 170 is mounted to the extension 125 of the base plate 120 so that the pack housing 170 may surround the outer surfaces of the battery modules 110. In addition, the pack housing 170 has a plurality of beads 172 having a concave-convex shape with a large width to length to form excellent durability or structural stability against external force.

3 is a schematic diagram showing an enlarged portion of the Y-shaped side reinforcing member is mounted in the medium-large battery pack of FIG. 2, and FIG. 4 is a partial schematic diagram showing an enlarged right portion of the medium-large battery pack of FIG.

Referring to these drawings, the connection member 140 in close contact with the pack housing (not shown), while connecting the side support members 130 and mutually prevent the refrigerant from escaping to the side of the battery module 110 This improves the cooling efficiency by inducing the refrigerant to penetrate in the vertical downward direction of the through holes 116 located between the battery modules 110.

5 is a schematic cross-sectional view showing a medium-large battery pack having a structure in which a bead is not formed at a portion adjacent to a refrigerant inlet according to another embodiment of the present invention.

Referring to FIG. 5, the refrigerant introduced into the refrigerant inlet 174 penetrates vertically between the respective battery modules 110 as shown by the arrow direction to cool the battery modules 110 and then to the refrigerant outlet 176. It consists of a structure that is discharged. In the pack housing 170A, except for the portion S adjacent to the refrigerant inlet 174, the indented beads 172 do not interfere with the flow of the refrigerant in the direction of fluid flow from the refrigerant inlet 174. It is formed in the structure of a big uneven | corrugated shape of long length.

Since the vertical cross-sectional area (a) of the coolant inlet 174 has a size of about 70% compared to the vertical cross-sectional area (b) of the coolant outlet 176, the coolant flow rate at the coolant inlet 174 is the coolant outlet 176. Relatively higher than the refrigerant flow rate of the site, it is possible to distribute the refrigerant evenly to the battery module (110R) located at a distance from the refrigerant inlet 174.

In addition, the indented beads 172 are formed in the portion of the pack housing 170A except for the portion S adjacent to the refrigerant inlet 174, so that the battery cells 110R are located farther than the refrigerant inlet 174. The refrigerant can be more evenly distributed evenly. That is, the difference in flow rate difference according to the distance difference between the refrigerant inlet 174 and the battery modules 110, 110N, and 110R may be further reduced.

6 is a schematic cross-sectional view showing a medium-large battery pack having a structure in which the depth of the beads is sequentially reduced in the direction of the refrigerant inlet in accordance with another embodiment of the present invention.

Referring to FIG. 6, the length of the pack housing 170B corresponding to the battery cell stacking direction L is relatively longer than the length corresponding to the battery cell width direction W, and the indented beads 172 include the battery cell. It is formed parallel to the width direction (W) of the, the concave and convex depth of the beads 172 in the region adjacent to the refrigerant inlet 174 sequentially reduced in the direction of the refrigerant inlet (174) (h ₁ <h ₂ <h ₃ ) This bead 172 structure can further increase the uniformity of the refrigerant flow rate distribution.

Although described above with reference to the drawings according to an embodiment of the present invention, those of ordinary skill in the art will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

As described above, the medium-large battery pack according to the present invention has a simple assembly process, a compact and stable structure, and a pair of connecting members pressurize both sides of the battery module assembly, so that the refrigerant is leaked to the outside. Outgoing can be prevented, which provides an efficient cooling system and can greatly improve the manufacturing processability and safety of the battery.

Claims (15)

A battery module assembly in which a plurality of battery modules in which a coolant flow path is formed vertically are arranged to be in contact with each other in a lateral direction; A pair of side support members surrounding each of the outermost battery modules in the battery module assembly to maintain the arrangement; At least one connection member coupling the side support members to each other; A base plate on which the battery module assembly is mounted; And a pack housing mounted to surround an outer surface of the battery module assembly, wherein the refrigerant for cooling the battery module is introduced through a refrigerant inlet located at an upper side of the battery module assembly, and proceeds in an arrangement direction of the battery module. While passing through each battery module vertically, medium and large battery packs characterized in that the discharge through the refrigerant outlet located on the lower side of the battery module assembly in the refrigerant inlet direction. According to claim 1, wherein the connecting member is composed of a pair of frames for pressing the top of the front and rear of the battery module assembly, respectively, the frame is the inner surface of the pack housing to induce the flow of refrigerant toward the top of the battery module Medium and large battery packs, characterized in that the close contact. The medium and large battery pack of claim 1, wherein a vertical cross-sectional area of the coolant inlet is smaller than a vertical cross-sectional area of the coolant outlet. The medium and large battery pack of claim 3, wherein the vertical cross-sectional area of the coolant inlet is 30 to 90% based on the vertical cross-sectional area of the coolant outlet. The medium and large battery pack of claim 1, wherein the pack housing has a length corresponding to a battery module arrangement direction longer than a length corresponding to a width direction of the battery module. The medium-large battery pack of claim 1, wherein a plurality of beads are formed in an upper surface of the pack housing in a length direction of the battery module assembly. The medium-large battery pack according to claim 6, wherein the beads consist of indented beads or protruding beads. The indentation bead of claim 7, wherein the indentation height of the bead has a structure in which its depth or height decreases toward the refrigerant inlet so as to minimize the influence on the refrigerant flow into the battery module assembly. Medium and large battery pack. The method of claim 7, wherein the protruding bead, the protruding height of the bead has a structure that is reduced in depth or height thereof toward the refrigerant inlet so as to minimize the influence on the refrigerant flow into the battery module assembly. Medium and large battery pack. The medium and large battery pack according to claim 6, wherein no beads are formed at a predetermined distance from the refrigerant inlet so as to minimize the influence on the refrigerant flow into the battery module assembly. The medium and large battery pack according to claim 1, wherein the refrigerant outlet has a suction fan mounted to allow the refrigerant introduced from the refrigerant inlet to pass through the battery module to the outlet. The medium and large battery pack of claim 1, wherein the base plate has a curved structure to support only lower ends of both sides of the battery module assembly, and a coolant flow path is formed between the base plate and the battery module assembly. The medium and large battery pack of claim 1, wherein the battery module has a structure in which a plurality of plate-shaped battery cells capable of charging and discharging or unit modules containing a plurality of the plate-shaped battery cells are mounted in a module case. The medium and large battery pack according to claim 13, wherein the battery cell is a lithium secondary battery. The medium and large battery pack of claim 13, wherein the battery pack is used as a power source for an electric vehicle or a hybrid electric vehicle.

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