KR20220129324A - Battery module and battery pack including the same - Google Patents

Abstract

A battery module according to an embodiment of the present invention includes: a battery cell laminate in which a plurality of battery cells are stacked; a module frame in which the battery cell laminate is accommodated; and a cooling frame located at the lower or upper portion of the module frame and having a cooling passage through which a refrigerant flows. The cooling frame includes an inlet and an outlet connected to the cooling passage. The inlet is located at one side of the cooling frame, and the outlet is located at the other side opposite to the one side of the cooling frame. A first direction change switch is disposed at the inlet, and a second direction change switch is disposed at the outlet. The battery module of the present invention is effective in resolving a cooling difference between battery cells.

Description

A battery module and a battery pack including the same

The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module with improved cooling performance and a battery pack including the same.

In modern society, as portable devices such as mobile phones, laptops, camcorders, and digital cameras are used in daily life, the development of technologies related to the mobile devices as described above is being actively developed. In addition, a rechargeable battery capable of charging and discharging is a measure to solve air pollution such as conventional gasoline vehicles using fossil fuels, and electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles ( P-HEV) is being used as a power source, and the need for the development of secondary batteries is increasing.

Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries do not have much memory effect compared to nickel-based secondary batteries, so charging and discharging are possible freely. , the self-discharge rate is very low and the energy density is high.

Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are respectively applied with a separator interposed therebetween, and a battery case for sealingly accommodating the electrode assembly together with an electrolyte.

In general, a lithium secondary battery may be classified into a can-type secondary battery in which the electrode assembly is embedded in a metal can and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch of an aluminum laminate sheet according to the shape of the exterior material.

In the case of secondary batteries used in small devices, 2-3 battery cells are disposed, but in the case of secondary batteries used in mid- to large-sized devices such as automobiles, a battery module in which a plurality of battery cells are electrically connected this is used In such a battery module, a plurality of battery cells are connected in series or parallel to each other to form a battery cell stack, thereby improving capacity and output. In addition, one or more battery modules may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.

In the case of a secondary battery, when the temperature is higher than an appropriate temperature, the performance of the secondary battery may be deteriorated, and in severe cases, there is a risk of explosion or ignition. In particular, in a plurality of secondary batteries, that is, a battery module or battery pack having battery cells, heat emitted from the plurality of battery cells is added up in a narrow space, so that the temperature may rise more rapidly and severely. In other words, in the case of a battery module in which a plurality of battery cells are stacked and a battery pack equipped with such a battery module, high output can be obtained, but it is not easy to remove heat generated from the battery cells during charging and discharging. If the heat dissipation of the battery cell is not performed properly, the battery cell deteriorates rapidly and the lifespan is shortened, and the possibility of explosion or ignition increases. Moreover, in the case of a battery module included in a battery pack for a vehicle, it is frequently exposed to direct sunlight and may be subjected to high temperature conditions such as summer or desert areas.

On the other hand, in the battery module or battery pack, the temperature of the central portion is higher than the temperature of the outer portion due to the structure in which the battery cells are dense. Since the temperature deviation inside the battery module leads to deterioration of the performance of the battery module, such as reduced output and shortened life, it is important to reduce the temperature deviation between the battery cells inside the battery module. That is, when configuring a battery module or battery pack, it can be said that it is very important to secure stable and effective cooling performance and at the same time to resolve the temperature deviation between the internal battery cells.

An object of the present invention is to provide a battery module effective for resolving a cooling deviation between battery cells and a battery pack including the same.

However, the problems to be solved by the embodiments of the present invention are not limited to the above-described problems and may be variously expanded within the scope of the technical idea included in the present invention.

A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked; a module frame in which the battery cell stack is accommodated; and a cooling frame positioned below or above the module frame and having a cooling passage through which a refrigerant flows. The cooling frame includes an inlet and an outlet connected to the cooling passage. The inlet portion is located on one side of the cooling frame, and the discharge portion is located on the other side opposite to the one side of the cooling frame. A first direction change switch is disposed on the inlet, and a second direction change switch is disposed on the outlet.

The cooling passage may include a left cooling passage and a right cooling passage respectively positioned at the outermost sides of the cooling frame, and a central cooling passage positioned between the left cooling passage and the right cooling passage.

The refrigerant introduced through the inlet may flow along the left cooling passage or the right cooling passage by the first direction change switch, and may flow along the central cooling passage by the second direction change switch.

The cooling passage may include a left cooling passage positioned between the left cooling passage and the central cooling passage and a right cooling passage positioned between the right cooling passage and the central cooling passage. The refrigerant having passed through the central cooling passage by the second direction change switch may flow along at least one of the left-center cooling passage and the right-center cooling passage.

The refrigerant flowing along at least one of the left-center cooling passage and the right-center cooling passage flows along the right cooling passage or the left cooling passage by the first direction change switch, and is discharged by the second direction change switch It can be released through wealth.

The first direction change changeover switch may be switched such that the inlet portion is connected to one of the left cooling passage and the right cooling passage.

The second direction change changeover switch may be switched such that the discharge unit is connected to one of the left cooling passage and the right cooling passage.

The left cooling passage, the right cooling passage, and the central cooling passage may extend along a longitudinal direction of the battery cell.

The first direction change switch and the second direction change switch, by periodically changing directions, the refrigerant may flow first from the left or right side of the cooling frame.

The battery module may further include a temperature sensor for measuring a temperature of each of the left and right portions of the battery module. Based on the temperature information measured by the temperature sensor, the first direction change switch may first supply the refrigerant to a cooling passage corresponding to a portion having a higher temperature among the left and right portions of the battery module.

According to embodiments of the present invention, by providing a cooling device capable of changing the flow of the cooling passage according to the temperature status of the battery cells, it is possible to reduce the cooling deviation in the battery module.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is an exploded perspective view showing a battery module according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a battery cell included in the battery module of FIG. 1 .
3 is a perspective view illustrating a cooling frame included in the battery module of FIG. 1 .
4 and 5 are plan views of the cooling frame of FIG. 3 viewed along the -z axis on the xy plane.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of explanation, the thickness of some layers and regions is exaggerated.

Also, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, it includes not only cases where it is “directly on” another part, but also cases where another part is in between. . Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, to be "on" or "on" the reference part means to be located above or below the reference part, and it means to be located "on" or "on" in the direction opposite to the gravity. not.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, throughout the specification, when it is referred to as "planar view", it means when the target part is viewed from above, and when it is referred to as "cross-section", it means when the cross-section obtained by cutting the target part vertically is viewed from the side.

1 is an exploded perspective view showing a battery module according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a battery cell included in the battery module of FIG. 1 .

1 and 2 , the battery module 100 according to an embodiment of the present invention includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked; a module frame 200 in which the battery cell stack 120 is accommodated; and a cooling frame 300 positioned below or above the module frame 200 and having a cooling passage.

First, referring to FIG. 2 , the battery cell 110 is preferably a pouch-type battery cell. For example, in the battery cell 110 according to the present embodiment, the two electrode leads 111 and 112 are opposite to each other and protrude from one end 114a and the other end 114b of the cell body 113, respectively. has a structure in In more detail, the electrode leads 111 and 112 are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110 . Meanwhile, as a matter of course, unidirectional pouch-type battery cells in which two electrode leads protrude in the same direction may be used.

Meanwhile, in the battery cell 110 , both ends 114a and 114b of the cell case 114 and one side 114c connecting them are adhered in a state in which an electrode assembly (not shown) is accommodated in the cell case 114 . It can be manufactured by In other words, the battery cell 110 according to the present embodiment has a total of three sealing portions 114sa, 114sb, 114sc, and the sealing portions 114sa, 114sb, 114sc are sealed by a method such as thermal fusion. , the other one side may be formed of a connection part 115 . The cell case 114 may be formed of a laminate sheet including a resin layer and a metal layer.

In addition, the connection part 115 may extend along one edge of the battery cell 110 , and a protrusion 110p of the battery cell 110 called a bat-ear is formed at an end of the connection part 115 . can be In addition, as the cell case 114 is sealed with the protruding electrode leads 111 and 112 interposed therebetween, a terrace portion 116 is formed between the electrode leads 111 and 112 and the cell body 113 . can That is, the battery cell 110 includes a terrace portion 116 formed to extend from the cell case 114 in a direction in which the electrode leads 111 and 112 protrude.

The battery cells 110 may be configured in plurality, and the plurality of battery cells 110 may be stacked to be electrically connected to each other to form the battery cell stack 120 . Referring to FIG. 1 , the battery cells 110 may be stacked along the y-axis direction to form the battery cell stack 120 . Accordingly, the electrode leads 111 and 112 may protrude toward the x-axis direction and the -x-axis direction.

On the other hand, in the direction in which the electrode leads 111 and 112 protrude (x-axis direction, -x-axis direction), the module frame 200 may be opened, and although not specifically shown, the open amount of the module frame 200 . Each end plate (not shown) may be located on the side. The module frame 200 and the end plate (not shown) may protect various electrical components including the battery cell stack 120 from external impact. To this end, the module frame 200 and the end plate must have a predetermined strength and may include a metal such as aluminum.

Although not specifically shown, the battery cell according to another embodiment of the present invention may be a prismatic battery cell or a cylindrical battery cell.

Hereinafter, the cooling frame according to the present embodiment will be described in detail with reference to FIGS. 3 to 5 .

3 is a perspective view illustrating a cooling frame included in the battery module of FIG. 1 . 4 and 5 are plan views of the cooling frame of FIG. 3 viewed along the -z axis on the xy plane.

1 and 3 to 5 , as described above, the cooling frame 300 according to the present embodiment is located at the lower or upper portion of the module frame 200 , and a cooling passage 300F is formed therein. have 1 shows the cooling frame 300 located below the module frame 200 as an embodiment of the present invention, of course, a cooling frame located above the module frame 200 is also possible.

The cooling frame 300 according to the present embodiment includes an inlet 310 and an outlet 320 connected to the cooling passage 300F. The refrigerant flows into the cooling passage 300F through the inlet 310 , and the introduced refrigerant flows along the cooling passage 300F and then is discharged to the outside through the outlet 320 . The refrigerant is a medium for cooling, and there is no particular limitation, but may be cooling water.

The inlet 310, the first direction change switch (300S1) is disposed, the outlet 320, the second direction change switch (300S2) is disposed. As will be described later, the first direction change switch 300S1 and the second direction change switch 300S2 are responsible for switching the movement path of the refrigerant .

The inlet 310 is located at one side of the cooling frame 300 , and the discharge unit 320 is located at the other side opposite to the one side. That is, the inlet 310 and the outlet 320 protrude from the cooling frame 300 to face each other. Although the inlet 310 and the outlet 320 are shown in the form of a pipe, if the refrigerant is supplied and discharged, the form is not particularly limited.

Meanwhile, partition walls 300W for guiding the flow of refrigerant are formed in the cooling frame 300 , and a cooling passage 300F is formed between the partition walls 300W. The cooling frame 300 according to the present embodiment may have an open top. The bottom portion 210 of the module frame 200 is bonded to the open upper portion of the cooling frame 300 , so that the cooling passage 300F may be sealed.

Meanwhile, although not specifically illustrated, when the cooling frame is located above the module frame 200 , the cooling frame may have an open lower portion. The ceiling portion 220 of the module frame 200 is bonded to the open lower portion of the cooling frame, so that the cooling passage may be sealed.

However, the types of the above cooling frames are examples, and as another embodiment, a structure in which the cooling passage 300F is formed without an open part is also possible.

The cooling passage 300F according to the present embodiment includes a left cooling passage 300L and a right cooling passage 300R, and a left cooling passage 300L and a right cooling passage 300R respectively located at the outermost sides of the cooling frame 300 . It may include a central cooling passage 300C located therebetween. For convenience of description, in this specification, the left side refers to the -y-axis direction, and the right side refers to the y-axis direction. Referring back to FIGS. 1 and 3 , the left cooling passage 300L, the right cooling passage 300R, and the central cooling passage 300C may have a shape extending in the longitudinal direction of the battery cell 110 . The longitudinal direction of the battery cell 110 is a direction parallel to the direction in which the electrode leads 111 and 112 protrude, and may be an x-axis direction or a -x-axis direction. In addition, although the left cooling passage 300L, the right cooling passage 300R, and the central cooling passage 300C are each illustrated as being one, there is no particular limitation on the number of passages, so that each may be configured in plurality.

The refrigerant introduced through the inlet 310 flows along the left cooling flow path 300L or the right cooling flow path 300R by the first direction change switch 300S1, and at the center by the second direction change switch 300S2. It may flow along the cooling passage 300C. 4 shows a state in which the refrigerant first flows along the left cooling flow path 300L by the first direction change switch 300S1, and FIG. 5 shows that the refrigerant flows through the first direction change switch 300S1. First, the flow along the right cooling passage 300R is shown.

The first direction change switch 300S1 may be switched such that the inlet 310 is connected to one of the left cooling passage 300L and the right cooling passage 300R. As an example, the central part is fixed and configured to rotate 90 degrees in a clockwise or counterclockwise direction, so that the flow of the refrigerant can be switched.

Similarly, the second direction change switch 300S2 may be switched such that the discharge unit 320 is connected to one of the left cooling passage 300L and the right cooling passage 300R. As an example, the central part is fixed and configured to rotate 90 degrees in a clockwise or counterclockwise direction, so that the flow of the refrigerant can be switched.

When the inlet 310 is connected to the left cooling passage 300L, the outlet 320 is preferably connected to the right cooling passage 300R. Conversely, when the inlet 310 is connected to the right cooling passage 300R, the outlet 320 is preferably connected to the left cooling passage 300L. To form such a connection form, the first direction change switch (300S1) and the second direction change switch (300S2) may be adjusted.

On the other hand, the cooling passage 300F is located between the left cooling passage 300LC and the right cooling passage 300R and the central cooling passage 300C located between the left cooling passage 300L and the central cooling passage 300C. It may include a right-core cooling passage 300RC.

The refrigerant flowing along the central cooling passage 300C by the second direction changeover switch 300S2 may flow along at least one of the left-center cooling passage 300LC and the right-center cooling passage 300RC.

The refrigerant flowing along at least one of the left-center cooling passage 300LC and the right-center cooling passage 300RC flows along the right cooling passage 300R or the left cooling passage 300L by the first direction changeover switch 300S1, It may be discharged through the discharge unit 320 by the second direction change switch (300S2).

Hereinafter, the flow of the refrigerant according to each case of FIGS. 4 and 5 will be described in detail.

First, referring to FIG. 4 , the inlet 310 may be connected to the left cooling flow path 300L by the first direction change switch 300S1 , and the discharge unit 320 is connected to the second direction change switch 300S2 . may be connected to the right cooling passage 300R by the

The refrigerant introduced through the inlet 310 flows along the left cooling flow path 300L by the first direction change switch 300S1, and then flows through the central cooling passage 300C by the second direction change switch 300S2. flows along The refrigerant that has passed through the central cooling passage 300C flows along the left-center cooling passage 300LC and the right-center cooling passage 300RC and then gathers again, and flows along the right-side cooling passage 300R by the first direction changeover switch 300S1. . Finally, the refrigerant is discharged through the discharge unit 320 by the second direction change switch (300S2).

That is, in the case of FIG. 4 , the refrigerant introduced through the inlet 310 first flows along the left cooling passage 300L. The refrigerant in the left cooling passage 300L has a lower temperature than the refrigerant in the right cooling passage 300R, which has already undergone a significant portion of heat exchange. That is, when the cooling performance of the left region of the battery cell stack 120 is to be increased, the cooling frame 300 according to the present embodiment has a shape as shown in FIG. 4 .

Next, referring to FIG. 5 , the inlet 310 may be connected to the right cooling flow path 300R by the first direction change switch 300S1 , and the discharge unit 320 may be connected to the second direction change switch 300S2 . may be connected to the left cooling passage 300L by the That is, the first direction change switch 300S1 and the second direction change switch 300S2 of FIG. 5 are in a state rotated 90 degrees clockwise as compared to the case of FIG. 4 .

The refrigerant introduced through the inlet 310 flows along the right cooling passage 300R by the first direction change switch 300S1, and then along the central cooling passage 300C by the second direction change switch 300S2. flows The refrigerant that has passed through the central cooling passage 300C flows along the left-center cooling passage 300LC and the right-center cooling passage 300RC and then gathers again, and flows along the left cooling passage 300L by the first direction changeover switch 300S1. . Finally, the refrigerant is discharged through the discharge unit 320 by the second direction change switch (300S2).

That is, in the case of FIG. 5 , the refrigerant introduced through the inlet 310 first flows along the right cooling passage 300R. The refrigerant in the right cooling passage 300R has a lower temperature than the refrigerant in the left cooling passage 300L, which has already undergone a significant portion of heat exchange. That is, when the cooling performance of the right region of the battery cell stack 120 is to be increased, the cooling frame 300 according to the present embodiment has a shape as shown in FIG. 5 .

As described above, in the cooling frame 300 according to the present embodiment, the refrigerant passing through the left cooling passage 300L or the right cooling passage 300R is configured to flow along the central cooling passage 300C. As the first direction change switch 300S1 and the second direction change switch 300S2 are switched, the introduced refrigerant may first flow through any one of the left cooling passage 300L and the right cooling passage 300R.

That is, the first direction change switch 300S1 and the second direction change switch 300S2 according to the present embodiment change directions periodically, so that the refrigerant may flow first from the left or right side of the cooling frame 300 . The left part and the right part of the battery cell stack 120 are configured to be preferentially cooled alternately periodically, so that the temperature deviation between the battery cells 110 can be greatly reduced. Resolving the temperature difference between the battery cells 110 may lead to performance improvement, such as an increase in output and lifespan of a battery module.

In addition, in the case of the battery cell stack 120 , since a plurality of battery cells 110 are stacked, the innermost battery cell 110 is difficult to dissipate heat. That is, in general, the temperature of the central portion of the battery cell stack 120 is higher than that of the outer portion. At this time, in the cooling frame 300 according to the present embodiment, the introduced refrigerant flows along the central cooling passage 300C immediately after passing through the left cooling passage 300L or the right cooling passage 300R. Relatively low heat exchange is made, that is, a refrigerant having a low temperature is designed to flow along the central cooling passage 300C, so that effective heat exchange is made with respect to the center of the battery cell stack 120 having a high temperature. Ultimately, cooling performance may be improved, and temperature variations between battery cells may be resolved.

Meanwhile, referring to FIGS. 4 and 5 , the battery module 100 according to the present embodiment may further include a temperature sensor 400 for measuring the temperatures of each of the left and right portions of the battery module 100 . have.

Based on the temperature information measured by the temperature sensor, the first direction change switch 300S1 may preferentially supply the refrigerant to a cooling passage corresponding to a portion having a higher temperature among the left and right portions of the battery module 100 .

That is, the first direction change switch 300S1 and the second direction change switch 300S2 are not converted at regular intervals, but based on the temperature data of the left and right portions measured through the temperature sensor 400, the temperature is higher The conversion can be controlled so that the refrigerant is first delivered to the part.

In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation, and may vary depending on the location of the object or the position of the observer. .

One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system to form a battery pack.

The battery module or battery pack may be applied to various devices. Specifically, it may be applied to transportation means such as electric bicycles, electric vehicles, hybrids, etc., but is not limited thereto and may be applied to various devices that can use secondary batteries.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

100: battery module
300: cooling frame
310: inlet
320: discharge unit
300S1: first direction change switch
300S2: second direction change switch

Claims (11)

a battery cell stack in which a plurality of battery cells are stacked;
a module frame in which the battery cell stack is accommodated; and
It is located at the lower or upper part of the module frame and includes a cooling frame having a cooling passage through which a refrigerant flows,
The cooling frame includes an inlet and an outlet connected to the cooling passage,
The inlet portion is located on one side of the cooling frame, and the discharge portion is located on the other side opposite to the one side of the cooling frame,
A first direction change switch is disposed in the inlet,
A battery module in which a second direction change switch is disposed in the discharge part. In claim 1,
The cooling passage includes a left cooling passage and a right cooling passage respectively positioned at the outermost side of the cooling frame, and a central cooling passage positioned between the left cooling passage and the right cooling passage. In claim 2,
The refrigerant introduced through the inlet, flows along the left cooling passage or the right cooling passage by the first direction change switch, and flows along the central cooling passage by the second direction change switch. In claim 3,
The cooling passage includes a left cooling passage located between the left cooling passage and the central cooling passage and a right cooling passage located between the right cooling passage and the central cooling passage,
The refrigerant, which has passed through the central cooling passage by the second direction change switch, flows along at least one of the left-center cooling passage and the right-center cooling passage. In claim 4,
The refrigerant flowing along at least one of the left-center cooling passage and the right-center cooling passage flows along the right cooling passage or the left cooling passage by the first direction change switch, and is discharged by the second direction change switch A battery module that is discharged through wealth. In claim 2,
The first direction change changeover switch is a battery module in which the inlet is switched to be connected to one of the left cooling passage and the right cooling passage. In claim 2,
The second direction change changeover switch is a battery module in which the discharge unit is switched to be connected to one of the left cooling passage and the right cooling passage. In claim 2,
The left cooling passage, the right cooling passage, and the central cooling passage extend along a longitudinal direction of the battery cell module. In claim 1,
The first direction change switch and the second direction change switch, by periodically changing the direction, the battery module to first flow the refrigerant from the left or right side of the cooling frame. In claim 1,
Further comprising a temperature sensor for measuring the temperature of each of the left part and the right part of the battery module,
Based on the temperature information measured by the temperature sensor, the first direction change switch is a battery module to preferentially supply the refrigerant to a cooling passage corresponding to a portion having a higher temperature among the left portion and the right portion of the battery module. A battery pack comprising the battery module according to claim 1 .

Images