KR20220039437A - Cell Module Having Uniform Temperature Distribution and method for Manufacturing Same - Google Patents

Abstract

The present invention relates to a battery module having uniform temperature distribution, and more specifically, to a battery module having uniform temperature distribution, wherein a plurality of battery cells (200) in which an electrode assembly is accommodated are vertically arranged in a cell case (210), the battery cells (200) are accommodated in a module case (100), and thermal grease (400) is applied to a predetermined part of the battery cells (200).

Description

A battery module having a uniform temperature distribution and a manufacturing method thereof {Cell Module Having Uniform Temperature Distribution and method for Manufacturing Same}

The present invention relates to a battery module and a method for manufacturing the same, and more particularly, to a battery module having a uniform temperature distribution capable of minimizing temperature deviation of battery cells accommodated in the battery module, and a manufacturing method thereof.

As technology development and demand for mobile devices such as smartphones, laptops, and digital cameras increase, technologies related to rechargeable batteries that can be charged and discharged are becoming active. Such secondary batteries are an alternative energy source for fossil fuels that cause air pollutants, such as electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and energy storage devices (ESSs). is being applied

Types of secondary batteries currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and the like, and the operating voltage of these unit secondary batteries is about 2.0V to 5.0V.

Therefore, when a higher output voltage is required, a battery module may be configured by connecting a plurality of battery cells in series, and it is common to manufacture a battery pack by having one or more such battery modules.

On the other hand, the battery cells constituting the battery module are in close contact and generate heat during repeated charging and discharging. there is. In particular, the laminate sheet constituting the case of the pouch-type battery cell widely used in high-output, large-capacity battery modules and battery packs is coated with a polymer material with low thermal conductivity, so it is difficult to effectively cool the temperature of the battery cell.

If the heat of the battery module generated during the charging/discharging process is not effectively removed, heat accumulation occurs and consequently accelerates the deterioration of the battery module, and in some cases may cause ignition or explosion. Therefore, the battery module is generally provided with means for cooling the battery cells.

That is, as shown in FIG. 1 which is a schematic diagram of a battery module according to the prior art, the battery module includes a plurality of battery cells 20 , and cooling fins 11 , 12 , 13 , disposed between the battery cells 20 , 14 , 15 , 16 , and 17 , the battery cells 20 , and a heat sink 30 disposed below the cooling fin structure 10 .

Here, the cooling fins are made of a metal material with excellent thermal conductivity, and the heat sink 30 receives the coolant from the inlet 1A located at one side and discharges it through the outlet 1B located at the other side. . Therefore, while the coolant passes through the heat sink, heat is exchanged with the cooling fin structure 10 , and as a result, the heat generated in the battery cell 20 is transferred to the coolant of the heat sink after passing through the cooling fin to the battery cell 20 . ) is cooled.

However, since the heat sink is located only at the lower end of one side of the battery cells, the temperature distribution of each battery cell is different, and furthermore, there is a problem that the energy density is lowered because cooling fins having a predetermined thickness are interposed between the battery cells.

On the other hand, Patent Document 1 includes a module case, a plurality of battery cells configured in the module case, a top cover provided between an upper portion of the battery cell and the module case, and a thermal conductive resin filled in a space in which the top cover is located. Disclosed is a battery module capable of dissipating heat generated in the upper portion of the battery module.

In addition, Patent Document 2 includes a plurality of battery structures arranged in one direction, a plurality of cooling fins interposed between adjacent battery structures, and a heat sink coupled to the ends of the plurality of cooling fins, and each cooling fin includes one Disclosed is a battery module emitting heat generated from a battery cell during a charging/discharging process having a structure in which a pair of cooling sub-fins are coupled face-to-face.

Both of these Patent Documents 1 and 2 have a configuration capable of cooling the heat generated in the battery cell, but discloses a battery module capable of minimizing the temperature difference between the battery cells and increasing the energy density of the battery module. there is not

Korean Patent Publication No. 2019-0092835 (2019.08.08) Korean Patent Publication No. 2017-0034775 (2017.03.29)

The present invention is to solve the above problems, and in a battery module in which a plurality of battery cells are accommodated, a battery module capable of minimizing a temperature difference between battery cells located in the center and battery cells located outside the battery module and a method for manufacturing the same is intended to provide

Another object of the present invention is to provide a battery module capable of increasing energy density while expecting a sufficient heat dissipation effect, and a method for manufacturing the same.

In the battery module according to the present invention for achieving this object, a plurality of battery cells 200 in which an electrode assembly is accommodated in a cell case 210 are vertically arranged, and the battery cells 200 are in the module case 100 . It is accommodated, and a thermal grease 400 is applied to a predetermined portion of the battery cell 200 .

In the battery module according to the present invention, the thermal grease 400 is applied to the battery cell 200 located in the center of the module case 100 .

Also, in the battery module according to the present invention, the thermal grease 400 may be applied along the first side surface 211 in the height direction and the second side surface 212 in the thickness direction of the battery cell 200 .

Also, in the battery module according to the present invention, a thermally conductive film 300 may be positioned between the battery cell 200 and the thermal grease 400 .

In addition, in the battery module according to the present invention, the thermally conductive film 300 may be in close contact with at least one side of the battery cell 200 .

In addition, in the battery module according to the present invention, the battery cell 200 may be positioned in a folded state so as to be in close contact with the first side surface 211 in the height direction and the second side surface 212 in the thickness direction.

In addition, in the battery module according to the present invention, the thermal conductive film 300 may be positioned at a predetermined portion of the battery cell 200 .

In addition, in the battery module according to the present invention, the module case 100 includes an upper cover 110 , a pair of side covers 120 facing each other, a front cover 130 and a rear cover 140 , and the A through hole 111 for injecting the thermal grease 400 may be formed in the upper cover 110 .

Also, in the battery module according to the present invention, a circular or polygonal partition wall 113 having a predetermined height in a shape surrounding the through hole 111 may be provided on the inner surface of the upper cover 110 .

In addition, the present invention is characterized in that the battery pack is provided with the battery module.

In addition, the present invention is characterized in that the device is provided with the battery pack.

In the present invention, a first step of accommodating a plurality of battery cells 200 to be perpendicular to the module case 100; and a second step of injecting the thermal grease 400 into the module case 100 to apply the thermal grease 400 to a predetermined portion of the battery cell 200 . can provide

In addition, the method for manufacturing a battery module according to the present invention may further include locating the thermally conductive film 300 on the outer surface of the battery cell 200 between the first step and the second step.

In addition, in the battery module manufacturing method according to the present invention, the thermal conductive film 300 is positioned on the outer surface of the battery cell 200 before the first step, and the first side surface in the height direction of the battery cell 200 ( 211) and the second side 212 in the thickness direction may be positioned in a folded state to be in close contact.

In the present invention, one or two or more non-conflicting configurations among the above configurations may be selected and combined.

According to the battery module and the manufacturing method thereof of the present invention, the thermal conductive film and the thermal grease are applied to the center of the centrally located battery cell among the plurality of battery cells constituting the battery module, so that the temperature deviation within the battery module can be minimized. There are advantages to being able to

In addition, according to the battery module and its manufacturing method of the present invention, since a thin thermal conductive film and liquid thermal grease with low viscosity are used, the increase in the volume of the battery module can be minimized, thereby increasing the energy density. .

In addition, there is an advantage in that the manufacturing process is simple because the liquid type thermal grease is injected after the battery cells are accommodated inside the case.

1 is a schematic diagram of a battery module according to the prior art.
2 is a perspective view of a battery module according to a first preferred embodiment of the present invention.
3 is an exploded perspective view of the battery module shown in FIG. 2 .
4 is a cross-sectional view taken along line AA′ of FIG. 3 .
5 is a perspective view illustrating a state in which a thermally conductive film is covered on the outside of the battery cell according to the first embodiment of the present invention.
6 is an enlarged view of the upper cover of the module case according to the first embodiment of the present invention.
7 is a perspective view illustrating a state in which a thermally conductive film is covered on the outside of a battery cell according to a second embodiment of the present invention.
8 is a perspective view of a battery module according to a second embodiment of the present invention.
9 is an internal perspective view of a battery module according to a third embodiment of the present invention.
10 is an internal perspective view of a battery module according to a fourth embodiment of the present invention.

In the present application, terms such as "comprises", "have", or "include" are intended to designate that the features, numbers, steps, components, parts, or combinations thereof described in the specification exist, and one or more other It should be understood that this does not preclude the possibility of addition or presence of features or numbers, steps, operations, components, parts, or combinations thereof.

In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. Throughout the specification, when it is said that a certain part is connected to another part, it includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of any component does not exclude other components unless otherwise stated, but means that other components may be further included.

Hereinafter, a battery module according to the present invention will be described with reference to the accompanying drawings.

Figure 2 is a perspective view of a battery module according to a first preferred embodiment of the present invention, Figure 3 is an exploded perspective view of the battery module shown in Figure 2, Figure 4 is a cross-sectional view taken along line AA' of Figure 3, and Figure 5 is a perspective view showing a state in which the thermally conductive film is covered on the outside of the battery cell according to the first embodiment of the present invention.

When the battery module according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 5 , the module case 100 having a substantially hexahedral shape, and a plurality of battery cells 200 disposed inside the module case 100 . ), the thermal conductive film 300 and the thermal grease 400 applied to a predetermined portion of the battery cell 200 are included.

First, the module case 100 will be described in detail. The module case 100 includes an upper cover 110 , a pair of side covers 120 facing each other so as to be positioned toward the side of the battery cell 200 , and a front cover. 130 , a rear cover 140 , and a lower cover 150 positioned under the battery cell 200 may be configured.

It is preferable that a through hole 111 for injecting the thermal grease 400 is formed in the upper cover 110 , and it is more preferable that the through hole 111 is located in the center of the upper cover 110 . When the through hole 111 is formed in the center of the upper cover 110 , the thermal grease 400 is centered on the battery cell 200 located in the center among the plurality of battery cells 200 accommodated in the module case 100 . can be injected, so it is advantageous to transfer heat generated in the battery cell 200 located near the center to the outside.

Here, a stopper 112 for opening and closing the through hole 111 may be additionally provided in the upper cover 110 .

A pair of side covers 120 protect the side surfaces of the battery cells 200 stacked inside the module case 100 , and the front cover 130 and the rear cover 140 are electrode leads of the battery cell 200 . (220) is disposed to face the direction in which they are located, and protects the ICB (Inter Connection Board) including the electrode lead 220 and the bus bar (not shown).

The lower cover 150 is positioned on the bottom surface of the battery cells 200 , and the lower cover 150 may be formed of a heat sink or a heat sink may be additionally provided between the battery cell 200 and the lower cover 150 . Do.

Although not shown in the drawings, a thermally conductive resin layer (not shown) for dissipating heat while fixing the battery cells 200 may be interposed between the lower cover 150 and the battery cells 200 . The base layer may be any one of a urethane resin, an epoxy resin, and a silicone having excellent thermal conductivity and adhesiveness.

On the other hand, the above-described upper cover 110, a pair of side covers 120, front cover 130, rear cover 140 and lower cover 150 can be separately manufactured and configured to be assembled with each other, If necessary, it is also possible to manufacture and configure some constituent parts integrally.

Next, the battery cell 200 will be described. The battery cell 200 accommodated in the inner space of the module case 100 includes a cell case 210 for accommodating an electrode assembly (not shown) and an electrode lead 220 as shown in FIGS. 3 and 5 . do.

The battery cells 200 having the above configuration are arranged in the module case 100 in close contact with the first side surfaces 211 , which are the height direction (Y-axis direction), in a vertically standing state, while being disposed in the thickness direction (X-axis direction). ) The second side 212 corresponding to the surface is positioned to be parallel to the upper cover 110 of the module case 100 .

Here, the cell case 210 is a pouch-type cell case, and after the electrode assembly is accommodated in at least one receiving unit, the receiving unit is sealed by fusion bonding the edge, and a pair of electrode leads 220 on both sides or one side of the electrode assembly ) is connected and protrudes to the outside of the cell case 210 . Of course, after the positive electrode tab and the negative electrode tab of the electrode assembly are electrically connected, they may be exposed to the outside of the cell case, or the cell assembly and the electrode lead may be directly connected to each other without the tab.

On the other hand, the electrode assembly is a jelly-roll type assembly having a structure in which a separator is interposed between a long sheet-shaped positive electrode and a negative electrode and then wound up, or a stack-type assembly in which a rectangular positive electrode and a negative electrode are stacked with a separator interposed therebetween. , a stack-folding type assembly in which unit cells are wound by a long separation film, or a lamination-stack type assembly in which battery cells are stacked with a separation membrane interposed therebetween and attached to each other, but is not limited thereto.

In addition, it is natural that there is no problem even if the electrolyte is replaced with a solid electrolyte or a semi-solid electrolyte in the form of a gel having an intermediate form between liquid and solid by adding an additive to the solid electrolyte in addition to the generally used liquid electrolyte.

The electrode assembly as described above is accommodated in a cell case, and the cell case is typically composed of a laminate sheet structure of an inner layer/metal layer/outer layer. Since the inner layer is in direct contact with the electrode assembly, it must have insulation and electrolyte resistance, and for sealing with the outside, the sealing property, that is, the sealing portion where the inner layers are thermally bonded to each other must have excellent thermal bonding strength. The material of the inner layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, polybutylene, etc., polyurethane resins and polyimide resins having excellent chemical resistance and good sealing properties, but is not limited thereto, Polypropylene excellent in mechanical properties such as tensile strength, rigidity, surface hardness, and impact resistance and chemical resistance is the most preferable.

The metal layer in contact with the inner layer corresponds to a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside.

And an outer layer is provided on the other side of the metal layer, and this outer layer can be made of a heat-resistant polymer with excellent tensile strength, moisture permeability and air permeability prevention so as to secure heat resistance and chemical resistance while protecting the electrode assembly. As an example, nylon or polyethylene terephthalate may be used, but is not limited thereto.

Continuing, the thermal conductive film 300 will be described in detail.

The thermally conductive film 300 in the present invention may be positioned on all or part of the first side 211 and the second side 212 of the cell case 210 .

For example, as shown in FIGS. 4 and 5 , the upper second side 212 constituting the cell case 210 and the pair of first side surfaces 211 are located on any one of the first side surfaces 211 . Preferably, it is more preferable to be disposed in close contact with the surfaces except for a portion of a predetermined region of the edge, in this case, the thermally conductive film 300 is extended from the first side 211 and then folded downward to the second side 212. is closely attached to

The thermal conductive film 300 as described above performs a function of minimizing a temperature deviation in one battery cell 200 . Specifically, the temperature distribution in the battery cell 200 is generally highest in the vicinity of the electrode lead 220 , and the temperature relatively decreases as the distance from the electrode lead 220 increases.

However, when the above-described thermally conductive film 300 is disposed along the second side 212 and the first side 211 , heat in the vicinity of the electrode lead 220 moves to the center, so that in the single battery cell 200 , Temperature variations can be minimized.

All of the battery cells 200 accommodated in the module case 100 may be in a state in which the thermal conductive film 300 is in close contact, but a predetermined number, specifically, a predetermined number of battery cells located in the center of the module case 100 . It is also possible to accommodate only the thermal conductive film 300 in close contact with the 200 .

On the other hand, the thermally conductive film 300 in the present invention is a silicone heat transfer sheet, or a resin composite sheet filled with a high thermal conductivity filler such as carbon fiber, carbon nanotube, or boron nitride (BN), a graphite heat dissipation sheet, and a thermally conductive elastomer If it has excellent thermal conductivity and electrical insulation, such as a thermally conductive adhesive tape, it is not limited to the above material.

In addition, the thickness of the thermal conductive film 300 is not particularly limited as long as it can efficiently move and disperse heat, but is preferably in the form of a film having a thickness of less than 1 mm so as to minimize an increase in the volume of the battery module, and the cell case A thermally conductive adhesive may be applied to one surface of the thermally conductive film 300 to increase adhesion with the 210 .

The thermal grease 400 is preferably applied to the second side surface 212 of the battery cells 200 facing the upper cover 110 of the module case 100, and is located in the center of the stored battery cells 200 . It is more preferably applied to the second side 212 of the disposed battery cells 200 .

When the plurality of battery cells 200 are vertically adhered, the temperature of the battery cell 200 located in the center is relatively higher than that of the battery cell 200 located on the outside. When applied, it is easy to move the heat from the center to the edge, so that the temperature deviation of each battery cell 200 can be minimized.

Here, the thermal grease 400 according to the present invention is a state in which a thermally conductive ceramic is added to silicon or oil, and since it corresponds to a known technology, detailed descriptions such as specific physical properties will be omitted.

6 is an enlarged view of the upper cover of the module case according to the first embodiment of the present invention.

Referring to FIG. 6 , a partition wall 113 having a predetermined height may be additionally provided on the inner surface of the upper cover 110 .

The thermal grease 400 in the present invention is preferably applied so as not to touch the battery cells 200 or the electrode leads 220 arranged in the center among the stored battery cells 200 . Accordingly, the barrier rib 113 is preferably formed while surrounding the through hole 111 , and it is more preferred that the through hole 111 be located in the center of the region formed by the barrier rib 113 .

As such, when the partition wall 113 having a predetermined height is provided on the inner surface of the upper cover 110 of the module case 100, the application area of the thermal grease 400 injected through the through hole 111 can be reliably limited. can

Here, the partition wall 113 may have a circular or polygonal shape, but it is obvious that the shape is not particularly limited as long as the injected thermal grease 400 can be applied to a desired area.

The above-described partition wall 113 may be manufactured integrally with the inner surface of the upper cover 110 of the module case 100 , or may be separately manufactured and then coupled to the inner surface of the upper cover 110 .

The battery module manufacturing method according to the first embodiment of the present invention having the configuration as described above includes the steps of accommodating a plurality of battery cells 200 so as to be perpendicular to the module case 100, and thermal conductivity on the outer surface of the battery cells 200 Positioning the film 300 , and injecting the thermal grease 400 into the module case 100 to a predetermined portion of the battery cell 200 , preferably a battery cell positioned in the center of the module case 100 . It may include applying the thermal grease 400 to the second side 212 of the 200 .

Of course, it is also possible to precede the step of disposing the thermal conductive film 300 on the outer surface of the battery cell 200 before accommodating the battery cell 200 in the module case 100 .

7 is a perspective view illustrating a state in which a thermally conductive film is covered on the outside of a battery cell according to a second embodiment of the present invention, and FIG. 8 is a perspective view of a battery module according to the second embodiment of the present invention.

The second embodiment of the present invention is the same as the first embodiment described with reference to FIGS. 2 to 6 except for the outer shape of the thermally conductive film 300 attached to the outer surface of the cell case 210. Only the conductive film 300 will be described.

7 and 8 , in the battery cell 200 according to the second embodiment of the present invention, a predetermined area of the battery cell 200, specifically, the battery cell, with two thermally conductive films 300 spaced apart from each other by a predetermined distance. On the other hand, the thermal grease 400 is disposed to be spaced apart from each other so as to be adjacent to the electrode leads 220 on both sides of the 200 , a partial region of the battery cell 200 that is not provided with the thermally conductive film 300 and the thermally conductive film 300 . ) can be applied to overlap with a part.

In this case, there is an advantage that the temperature deviation of the battery cells 200 accommodated in the module case 100 can be reduced while reducing the amount of the thermal conductive film 300 .

The battery module manufacturing method according to the second embodiment of the present invention, except for the number and position of the thermally conductive film 300 located on the outer surface of the cell case 210, the battery according to the first embodiment described above Since it is the same as the manufacturing method of the module, a detailed description thereof will be omitted.

9 is an internal perspective view of a battery module according to a third embodiment of the present invention. Except that the thermal conductive film 300 is omitted and only the thermal grease 400 is provided on the outer surface of the cell case 210, the rest is the same as the first embodiment described with reference to FIGS. 2 to 6 .

In the third embodiment of the present invention, the upper surface of the battery cell 200 accommodated in the module case 100, or the upper surface and some side surfaces of the battery cell 200 located near the center of the module case 100. The second side surface 212 or the second side surface 212 and a pair of first side surfaces 211 facing each other may be in a state in which the thermal grease 400 is applied to a predetermined region.

When the thermal grease 400 is injected through the through-hole 111 of the module case 100 , it is applied to the second side 212 of the battery cell 200 , and some of it enters the space between the adjacent battery cells 200 . It may flow down and may be applied to some areas of the pair of first side surfaces 211 .

In the battery module manufacturing method according to the third embodiment of the present invention, the battery module according to the first embodiment, except that the disposing step of the thermally conductive film 300 located on the outer surface of the cell case 210 is omitted. Since the manufacturing method is the same, a detailed description thereof will be omitted.

10 is an internal perspective view of a battery module according to a fourth embodiment of the present invention. Except for a prismatic battery cell instead of a pouch-type battery cell, the rest are the same as in the first embodiment described with reference to FIGS. 2 to 6 .

As described above, the battery module according to the present invention may be a single or a plurality of battery packs constituting an aggregate, and such a battery module or battery pack may be used in various devices, for example, automobiles such as electric vehicles or hybrid vehicles. can be applied.

As the specific parts of the present invention have been described in detail above, for those of ordinary skill in the art, these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby, It is obvious to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and it is natural that such variations and modifications fall within the scope of the appended claims.

100: module case
110: upper cover
111: through hole 112: stopper
113: bulkhead
120: side cover
130: front cover
140: back cover
150: lower cover
200: battery cell
210: cell case
211: first side 212: second side
220: electrode lead
300: thermally conductive film
400: summer grease

Claims (14)

A plurality of battery cells 200 in which the electrode assembly is accommodated in the cell case 210 are vertically disposed, and the battery cells 200 are accommodated in the module case 100,
A battery module, characterized in that the thermal grease (400) is applied to a predetermined portion of the battery cell (200).
According to claim 1,
The thermal grease 400 is a battery module, characterized in that applied to the battery cell 200 located in the center of the module case (100).
3. The method of claim 2,
The battery module, characterized in that the thermal grease 400 is applied along the first side 211 in the height direction and the second side 212 in the thickness direction of the battery cell 200.
The method of claim 1,
A battery module, characterized in that a thermally conductive film (300) is positioned between the battery cell (200) and the thermal grease (400).
5. The method of claim 4,
The thermally conductive film 300 is a battery module, characterized in that in close contact with one side or more of the battery cell (200).
6. The method of claim 5,
The battery module, characterized in that it is positioned in a folded state so as to be in close contact with the first side surface 211 in the height direction and the second side surface 212 in the thickness direction of the battery cell 200 .
According to claim 1,
A battery module, characterized in that a thermally conductive film (300) is positioned on a predetermined portion of the battery cell (200).
According to claim 1,
The module case 100 includes an upper cover 110, a pair of side covers 120 facing each other, a front cover 130 and a rear cover 140,
A battery module, characterized in that the upper cover (110) has a through hole (111) for injecting the thermal grease (400) is formed.
9. The method of claim 8,
A battery module, characterized in that a circular or polygonal partition wall (113) having a predetermined height in a shape surrounding the through hole (111) is provided on the inner surface of the upper cover (110).
A battery pack comprising a battery module according to any one of claims 1 to 9.
A device comprising the battery pack according to claim 10 .
In the method for manufacturing the battery module according to any one of claims 1 to 9,
A first step of accommodating a plurality of battery cells 200 so as to be perpendicular to the module case 100; And
and a second step of injecting the thermal grease 400 into the module case 100 and applying the thermal grease 400 to a predetermined portion of the battery cell 200 .
13. The method of claim 12,
Between the first step and the second step, the method of manufacturing a battery module, characterized in that it further comprises the step of positioning a thermally conductive film (300) on the outer surface of the battery cell (200).
13. The method of claim 12,
Doedoe positioning the thermal conductive film 300 on the outer surface of the battery cell 200 before the first step,
A method of manufacturing a battery module, characterized in that the battery cell 200 is positioned in a folded state so as to be in close contact with the first side surface 211 in the height direction and the second side surface 212 in the thickness direction.

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