KR101807114B1 - Battery module and battery pack including the same - Google Patents

Abstract

According to the present invention, there are provided a cell assembly having a plurality of secondary cells, a cell assembly having a channel formed between the secondary cells, and a side cover disposed on one side of the cell assembly to cover one side of the cell assembly, And a side cover unit including a main body and a window for allowing air to flow inward from the outside of the side cover body so that air introduced into the inside of the side cover body through the window is drawn into the flow passage, The air flow space may be narrowed in a direction away from the battery module.

Description

[0001] The present invention relates to a battery module and a battery pack including the battery module,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery module, and more particularly, to a battery module having a compact structure and capable of improving battery cooling efficiency, and a battery pack including the battery module.

2. Description of the Related Art In recent years, demand for portable electronic products such as notebook computers, video cameras, and portable telephones has rapidly increased, and electric vehicles, storage batteries for energy storage, robots, and satellites have been developed in earnest. Are being studied actively.

The secondary rechargeable batteries are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel- It is very popular because of its low self-discharge rate and high energy density.

These lithium secondary batteries mainly use a lithium-based oxide and a carbonaceous material as a cathode active material and an anode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate each coated with such a positive electrode active material and a negative electrode active material are disposed with a separator interposed therebetween, and an outer casing, that is, a battery case, for sealingly storing the electrode assembly together with the electrolyte solution.

Generally, a lithium secondary battery can be classified into a can type secondary battery in which an electrode assembly is embedded in a metal can, and a pouch type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the casing.

In recent years, secondary batteries are widely used not only in small-sized devices such as portable electronic devices, but also in medium to large-sized devices such as automobiles and electric power storage devices. When used in such a medium to large-sized apparatus, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, pouch-type secondary batteries are widely used because they are easy to store and stack. The battery module may be referred to as a component in which a plurality of secondary batteries are connected in series or in parallel in order to increase capacity and output.

When constructing such a battery module, one of the major issues is the problem of cooling. The secondary battery can generate heat by itself in the process of repeated charging and discharging. Since the plurality of secondary batteries are concentrated in a narrow space in the battery module, the temperature of the battery module may increase significantly during use. In addition, since the middle- or large-sized devices such as an automobile or a power storage device are often used outdoors, the temperature of the battery module mounted thereon can be further increased in a high-temperature situation such as summer. However, when the temperature of the secondary battery included in the battery module is higher than the proper temperature, the performance may be deteriorated and, in severe cases, there is a risk of explosion or ignition. Therefore, securing the cooling performance in constituting the battery module is a very important problem.

Two types of cooling methods of battery module are air cooling type and water cooling type. Air cooling type is more widely used than water cooling type due to leakage current or waterproofing problem of secondary battery. Such an air cooling type cooling system often includes a duct for introducing a fluid such as outside air into the battery module and for discharging the air inside the battery module to the outside. The air-cooled battery module is designed to have a flow path through which air can flow between the secondary batteries.

However, the conventional air-cooled type battery modules have different cooling efficiency depending on the distance from the duct inlet, resulting in a cooling deviation between a plurality of battery cells. In other words, the flow path closer to the duct inlet has a relatively larger amount of cooling air flow than the flow path farther away, resulting in cooling variations between battery cells depending on the location. Such a cooling deviation between the battery cells becomes one of the factors that make the performance of the battery cells uneven.

In addition, a battery module installed in a limited space such as an automobile must be able to supply a desired output and have a small volume. However, the conventional air-cooled battery module has a disadvantage in that it has a large volume because it includes a duct as a cooling air passage, and furthermore, a space efficiency of the vehicle is deteriorated due to a cooling air circulating fan or other auxiliary device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a battery module and a battery pack including the battery module, which are capable of improving battery cooling efficiency while having a compact structure.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a battery module comprising: a cell assembly having a plurality of secondary cells and a flow path formed between the secondary cells; A side cover body disposed on one side of the cell assembly and covering one side of the cell assembly and having an air flow space formed therein and a window for introducing air inward from the outside of the side cover body, And a side cover unit configured to allow air introduced into the side cover body through the window to be drawn into the flow passage, wherein the side cover body is configured to narrow the air flow space in a direction away from the window have.

Wherein a plurality of the flow paths are formed in a vertical direction at predetermined intervals with at least one secondary battery being interposed therebetween, and the side cover unit is provided in the upper end portion of the side cover body so that the flow of air in the air flowing space From the top to the bottom.

The side cover body may have at least one step so that the air flow space narrows from the upper side to the lower side.

Wherein the side cover body includes: an upper plate part communicating with the window and covering an upper area of one side of the cell assembly; And a lower plate part formed as one body with the upper plate part, covering a lower area of one side of the cell assembly, and the air flow space being narrower than the upper plate part.

The side cover body may further include an inclined portion formed between the upper plate portion and the lower plate portion so that the width is gradually narrowed.

The inclined portion may have a tapered inclined surface so that the width from the upper plate portion toward the lower plate portion is narrowed.

The inclined portion may have an inclined surface having a predetermined curvature in the direction from the upper plate portion to the lower plate portion.

The window may include an air inlet protruding from the upper end of the side cover body onto the cell assembly.

The air inlet may be formed in a direction parallel to the paper, the opening through which the air is introduced.

Wherein the window has a plurality of ribs which are provided in an opening of the air inlet and are formed in a plate shape and whose inner and outer directions are inclined at a predetermined angle in a direction parallel to the ground surface, And at least one of the inlet cover and the inlet cover may be bent.

The side cover unit can cover both side surfaces of the cell assembly in pairs.

At least one of the two side cover units may further include an air suction fan inside the side cover body.

According to another aspect of the present invention, a battery pack including the above-described battery module may be provided.

According to another aspect of the present invention, an automobile including the above-described battery module can be provided. The automobile may include a hybrid vehicle, a plug-in hybrid vehicle, and a pure electric vehicle driven only by an electric motor and a battery without an internal combustion engine.

According to an aspect of the present invention, an air-cooled battery module having a compact structure that can be effectively disposed even in a place where a large number of parts such as an automobile are concentrated can be provided.

According to another aspect of the present invention, since the air flow rate supplied to each unit battery cell becomes uniform, the cooling deviation between the unit battery cells can be reduced.

1 is a perspective view illustrating a configuration of a battery pack according to an embodiment of the present invention.
Fig. 2 is a partially separated perspective view of Fig. 1. Fig.
3 is a perspective view illustrating a configuration of a battery module according to an embodiment of the present invention.
4 is an exploded perspective view of the configuration of the battery module of Fig.
Fig. 5 is a perspective view showing a pair of side cover units in Fig. 3. Fig.
Fig. 6 is an exploded perspective view showing the opening cover separated from the window of Fig. 5; Fig.
7 is a front view of the opening cover shown in Fig.
8 is a cross-sectional view taken along the line B-B 'in Fig.
9 is a schematic cross-sectional view of a battery pack for explaining an air flow inside a battery module according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be construed as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The embodiments of the present invention are provided to explain the present invention more fully to the ordinary artisan, so that the shape and size of the components in the drawings may be exaggerated, omitted or schematically shown for clarity. Thus, the size or ratio of each component does not entirely reflect the actual size or ratio.

FIG. 1 is a perspective view showing a configuration of a battery pack according to an embodiment of the present invention, and FIG. 2 is a partially separated perspective view of FIG.

Referring to these figures, the battery module 200 according to the present invention can be housed in a battery pack case 100 that can be assembled and disassembled from each other by a lower case 120 and an upper case 110.

The battery pack case 100 can be manufactured as shown in FIGS. 1 and 2 so that a part of the side cover unit 240 described below, that is, the window 250 can be exposed to the outside . In addition, the battery pack case 100 is entirely hermetically sealed so that moisture, foreign matter, and the like are prevented from flowing into the battery pack case 100. An O-ring may be further provided at an assembly site of the lower case 120 and the upper case 110. [

3 is a perspective view showing a configuration of a battery module according to an embodiment of the present invention, FIG. 4 is an exploded perspective view of the configuration of the battery module of FIG. 3, and FIG. 5 is a cross- Fig.

Referring to these drawings, a battery module 200 according to an embodiment of the present invention may include a cell assembly 210 and a side cover unit 240.

The cell assembly 210 includes one or more secondary batteries 211. In particular, in the battery module 200, the cell assembly 210 may be a collection of secondary batteries 211 having a plurality of secondary batteries 211. Here, the secondary battery 211 included in the cell assembly 210 may be a pouch type secondary battery 211. In this case, the pouch type secondary batteries 211 may be stacked in one direction, for example, as shown in the figure, in the vertical direction.

Meanwhile, the cell assembly 210 may include a stacking frame for stacking the pouch-shaped secondary batteries 211. Here, the lamination frame is a structure used for laminating the secondary batteries 211, which can hold the secondary batteries 211 to prevent the secondary batteries 211 from flowing, and can be stacked so as to be able to guide the assembly of the secondary batteries 211 have.

Such a lamination frame can be replaced with various terms such as a cartridge, and can be configured in the form of a square ring with a hollow central portion. In this case, the four corners of the stacking frame may be located on the outer peripheral portion of the secondary battery 211. [

In addition, the cell assembly 210 may be configured such that the secondary cells 211 are stacked, and at least two or more secondary cells 211 are spaced apart from each other by a predetermined distance. With this spacing configuration, a flow path can be formed between the secondary batteries 211. [ That is, the cell assembly 210 may be configured to form a flow path between the secondary cells 211, which may be realized by a stacking frame. Accordingly, when a fluid, such as air, flows from the outside into the cell assembly 210, the air can exchange heat with the secondary battery 211 while flowing through the flow path formed between the secondary cells 211.

At this time, heat exchange between the secondary battery 211 and the air can be performed by direct contact of the secondary battery 211 with air. Alternatively, the stacking frame may be provided with a cooling fin close to the secondary battery 211. By making air contact with the cooling fin, heat exchange between the secondary battery 211 and the air can be indirectly performed have.

The battery module 200 according to the present invention may further include an upper plate 220 and a lower plate 230, as shown in FIGS.

The upper plate 220 and the lower plate 230 may be formed in the form of plates having an approximately large area and are respectively located at the upper and lower portions of the cell assembly 210, . The upper plate 220 and the lower plate 230 provide mechanical support for the battery module 200 and protect the cell assembly 210 from external shocks at the top and bottom of the cell assembly 210 Can play a role. For this purpose, the upper plate 220 and the lower plate 230 may be made of a metal such as steel to ensure rigidity.

The cell assembly 210 may be interposed between the upper plate 220 and the lower plate 230 and may be fixed between the upper plate 220 and the lower plate 230. For this purpose, the upper plate 220 and the lower plate 230 may have a structure for coupling with the cell assembly 210. For example, as shown in FIGS. 3 and 4, upper and lower insertion holes may be formed at four corners of the cell assembly 210. In this case, So that the cell assembly 210 can be fixed to the lower plate 230 by inserting each insertion rod of the lower plate 230 into the insertion hole of the cell assembly 210. A hole for inserting the insertion bar of the lower plate 230 may be formed in the upper plate 220, and the insertion bar may be inserted and fixed with a nut or the like.

Meanwhile, the side cover unit 240 may be positioned on one side of the cell assembly 210 to cover the corresponding side of the cell assembly 210. For example, when the battery module 200 is viewed in the direction of the arrow A in FIG. 4, the side cover unit 240 separates the cell assembly 210 from the front, rear, left, The left side surface, and the right side surface. That is, in the present embodiment, the pair of side cover units 240 are configured to cover both the left side and the right side of the cell assembly 210, but they may be configured to cover only one side as the case may be.

Particularly, the side cover unit 240 according to the present invention can also serve as a duct for blowing air into and out of the battery module 200 while protecting the side area of the cell assembly 210.

The side cover unit 240 may include a window 250 and a side cover body 260, as shown in FIGS.

The window 250 is a part serving as a vent for allowing air to flow in and out of the battery module 200. The battery module 200 according to the present embodiment may be integrally formed with the side cover body 260 so that the window 250 extends over the cell assembly 210 from the upper end of the side cover body 260. In this way, since the window 250 is formed integrally with the side cover body 260, the volume of the battery module 200 can be made compact.

Further, other electric components such as BMS may be installed on the front surface and / or the top surface of the cell assembly 210. As shown in FIGS. 1 and 2, the battery module 200 may be integrated in a substantially rectangular parallelepiped shape and housed in a box-shaped battery pack case 100. At this time, only the air inlet 251 of the window 250 of the battery module 200 may be exposed to the outside of the battery pack case 100.

Fig. 6 is an exploded perspective view showing the opening cover 253 separated from the window 250 in Fig. 5, Fig. 7 is a front view of the opening cover 253 shown in Fig. 5, B-B ', respectively.

As shown in these figures, the window 250 may include an air inlet 251 communicating with the interior of the side cover body 260, and an opening cover 253. The air inlet 251 may be formed with the opening 252 in a horizontal direction so that external air may enter the side of the cell assembly 210 and flow under the side cover body 260. The opening cover 253 may be installed in the opening 252 of the air inlet 251 to control the flow direction, speed, amount, etc. of the air flowing into the air inlet 251.

The opening cover 253 may have a plurality of ribs 253a, as shown in Figs. Each of the ribs 253a may be configured in the form of a flat plate. That is, the ribs 253a may be formed in a plate shape having a thin thickness in the vertical direction. A plurality of such ribs 253a are provided and are arranged so as to be spaced apart from each other by a predetermined distance. Since the ribs 253a are formed in a plate shape, air passing through the space between the ribs 253a can flow along the surface of the ribs 253a.

More specifically, in Fig. 8, the opening cover 253 is provided with three ribs 253a, and each of the ribs 253a is inclined so as to be gradually lowered from the inside toward the outside . According to such a constitution of the present invention, the air passing through the opening cover 253 is also inclined along the inclined shape of the rib 253a by the inclined ribs 253a. For example, when the outside air is introduced, the air moves inward in passing through the opening cover 253, and in accordance with the inclined shape of the rib 253a, which gradually increases toward the inside, It may have a flow moving upward.

At least one of the plurality of ribs 253a may be configured such that at least one of the inner and outer ends is bent. According to this configuration of the present invention, air passing through the opening cover 253 flows in an inclined manner along the inclined portion 253b, and the flow direction can be limited or changed by the bent portion 253c . Particularly, according to this configuration of the present invention, foreign matter, moisture, dust, etc. can be more effectively blocked by the bent portion 253c. Therefore, only the outside air can enter the inner space of the side cover body 260 covering one side of the cell assembly 210 through the window 250.

3, 5 and 6, the side cover body 260 may have a shape and size corresponding to one side of the cell assembly 210 to cover one side of the cell assembly 210 have. Particularly, when the side cover body 260 is mounted on one side of the cell assembly 210, the side cover body 260 is positioned between the inside of the side cover body 260 and one side of the cell assembly 210, (S). Here, the air flow space S is defined as a space formed inside the side cover body 260 due to the concave inner surface of the side cover body 260, which is closely attached to the periphery of the cell assembly 210 do.

5 and 6, the side cover body 260 includes a top plate portion 261 covering an upper region and a lower region of one side of the cell assembly 210, And an inclined portion 262 formed between the lower plate portion 263 and the upper plate portion 261 and the lower plate portion 263.

The side cover body 260 is composed of the upper plate portion 261, the lower plate portion 263 and the inclined portion 262 so that the inner air flow space S can be narrowed from the upper portion to the lower portion. For example, as shown in Fig. 9, the side cover body 260 according to the present embodiment has a step and an inclined surface in an upper-to-lower direction so that the air flow space S becomes narrower. The upper plate portion 261 and the lower plate portion 263 form a step and the inclined portion 262 forms an inclined surface between the upper plate portion 261 and the lower plate portion 263.

The upper plate 261 may be in a limited communication with the air inlet 251 of the window 250 through a cutout formed by partially cutting the upper surface. Accordingly, the air introduced through the window 250 flows downward from the upper portion of the side cover body 260.

The upper plate 261 may further include an air suction fan 270. The air suction fan 270 serves to suck and discharge the outside air into the battery module 200. Since the air intake fan 270 is disposed outside the battery module 200, that is, inside the side cover unit 240, the peripheral space utilization is reduced when the battery module 200 is installed in a limited space such as a vehicle. Can be increased.

The inclined portion 262 is provided between the upper plate portion 261 and the lower plate portion 263 so that the airflow can smoothly flow from the upper portion to the lower portion, that is, from the upper plate portion 261 to the lower plate portion 263 side . For example, when the side cover body 260 includes only the upper plate portion 261 and the lower plate portion 263, that is, a step, the vortex increases at the boundary between the upper plate portion 261 and the lower plate portion 263, It can interfere. However, according to the inclined portion 262 of the present embodiment, air flows smoothly from the lower end surface of the upper plate portion 261 to the upper end surface of the lower plate portion 263 with an inclined surface, so that vortices hardly occur.

In this embodiment, the inclined portion 262 is configured to have an inclined surface having a predetermined inclination, but unlike the present embodiment, the inclined portion 262 may be configured to have a curved surface having a predetermined curvature.

9 is a schematic cross-sectional view of a battery pack for explaining an air flow inside a battery module according to an embodiment of the present invention.

Hereinafter, with reference to FIG. 9, the air flow inside the battery module will be described in more detail.

In the battery module 200, the temperature of the secondary batteries 211 can be monitored in real time by the temperature measuring sensor. When the temperature of the secondary batteries 211 becomes higher than a proper level, the air intake fan 270 is operated to allow the outside air to flow into the battery module 200.

The cell assembly 210 covered by the side cover body 260 has a plurality of flow paths arranged in the vertical direction between the secondary batteries 211 as indicated by P in FIG.

Accordingly, as indicated by the arrows, the outside air introduced through the window 250 can be branched into the respective channels arranged in the vertical direction while flowing in the downward direction from the upper portion of the side cover body 260 .

The air supplied from the side cover body 260 to the cell assembly 210 can be exchanged with the adjacent secondary batteries 211 while flowing through various flow paths as shown in FIG. At this time, the secondary battery 211 may be directly exposed to the flow path, or may be further provided with a cooling fin.

On the other hand, assuming that the width of the air flow space S is constant in the downward direction from the upper side of the side cover body 260, a branch point relatively far from the first air inflow point, that is, The amount of air flowing into the flow paths may be smaller than the amount of air flowing into the flow paths of the upper region.

In other words, as the air flow progresses downward from the upper portion of the side cover body 260 in the uppermost window 250, the air is distributed to the respective upper and lower flow paths, That is, the height of the cell assembly 210, and the surface contact resistance is increased. As a result, the air flow rate supplied to the lower region of the cell assembly 210 is relatively slower than that of the upper region, and the air flow rates supplied to the upper and lower region flow channels are different from each other. If the air flow rate is unequally supplied to the various flow paths as described above, a cooling deviation between the secondary batteries 211 can be increased.

However, according to the present invention, the side cover body 260 is provided so as to narrow the air flow space S in the direction away from the window 250, as described above. According to the Bernoulli principle, The air flow rate may not be decelerated. That is, according to the construction of the side cover body 260 of the present invention, even if the flow rate decreases from the upper portion to the lower portion and the surface contact resistance increases, the air flow space S becomes narrower, . Therefore, the flow rate supplied per unit time between the flow paths arranged in the upper and lower regions of the cell assembly 210 does not show a large difference. In other words, the flow rate of the air to the flow path becomes equal to each other, and the cooling deviation is reduced accordingly.

Another side cover unit 240 having the same configuration may be further mounted on the other side of the cell assembly 210. The air passing through the flow path flows out from the lower side to the upper side through the side cover body 260 covering the other side of the cell assembly 210 and is discharged to the outside of the battery module 200 through the window 250 have.

In this embodiment, two side cover units 240 are configured to cover both sides of the cell assembly 210. However, the side cover unit 240 may be configured to cover only one side of the cell assembly 210, The side cover unit may be omitted on the side surface. In this case, the battery pack case 100 may be provided with ventilation openings for discharging air, so that the air discharged from the flow path may be discharged directly to the outside of the battery pack case 100.

The battery pack according to the present invention includes the above-described battery module. In this case, the battery pack may further include a case for accommodating the battery module, various devices for controlling charge / discharge of the battery module, such as a battery management system (BMS), a current sensor, a fuse, and the like.

The battery module according to the present invention can be applied to an automobile such as an electric car or a hybrid car. That is, the automobile according to the present invention may include a battery module according to the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

In the present specification, terms indicating upward, downward, leftward, and rightward directions are used, but these terms are for convenience of explanation only, and may vary depending on the position of the object or the position of the observer. Lt; / RTI >

100: battery pack case 110: upper case
120: lower case 200: battery module
210: cell assembly 220: upper plate
230: lower plate 240: side cover unit
250: window 260: side cover body
270: Fan S: Air flow space
P: Euro

Claims (14)

A battery pack having a battery module housed in a box-shaped battery pack case,
A cell assembly having a plurality of secondary cells and a flow path formed between the secondary cells;
An upper plate and a lower plate which are located at upper and lower portions of the cell assembly and cover upper and lower portions of the cell assembly, respectively; And
And a side cover unit that covers a left side surface and a right side surface of the cell assembly in which the inlet and the outlet of the flow path are located,
The side cover unit includes:
A side cover body provided in the shape of a cover corresponding to the left and right sides of the cell assembly and having an air inlet fan on the inside and an air flow space on the bottom side being narrower than the top side; And
And a window connected to an upper end of the side cover body and protruding above the cell assembly and exposed to the outside of the battery pack case. delete The method according to claim 1,
Wherein the side cover body has at least one step so that the air flow space narrows from the upper side to the lower side. The method according to claim 1,
The side cover body includes:
An upper plate portion communicating with the window and covering one side upper region of the cell assembly; And
And a lower plate part which is formed as one body with the upper plate part and covers one side lower area of the cell assembly, and the air flow space is formed narrower than the upper plate part. 5. The method of claim 4,
The side cover body includes:
Further comprising an inclined portion formed between the upper plate portion and the lower plate portion such that the width is gradually narrowed. 6. The method of claim 5,
Wherein the inclined portion is tapered so as to be narrowed in the direction from the upper plate portion toward the lower plate portion. 6. The method of claim 5,
Wherein the inclined portion has a predetermined curvature from the upper plate portion toward the lower plate portion. delete The method according to claim 1,
The air inlet
And an opening through which air is introduced is formed in a direction parallel to the paper. The method according to claim 1,
Wherein the window has a plurality of ribs which are provided in an opening of the air inlet and are formed in a plate shape and whose inner and outer directions are inclined at a predetermined angle in a direction parallel to the ground surface, And at least one of the inlet cover and the outlet cover is bent. delete delete delete An automobile comprising the battery pack according to claim 1.

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