WO2013065945A1

WO2013065945A1 - Battery having air-permeable case

Info

Publication number: WO2013065945A1
Application number: PCT/KR2012/007467
Authority: WO
Inventors: Eun Jin Kim
Original assignee: SK Innovation Co Ltd
Current assignee: SK Innovation Co Ltd
Priority date: 2011-11-01
Filing date: 2012-09-18
Publication date: 2013-05-10
Anticipated expiration: 2014-05-01
Also published as: KR20130047840A; KR101321371B1

Abstract

Provided is a battery having an air-permeable case capable of increasing cooling performance using air by having the air-permeable case limiting passage of moisture and foreign material but allowing air to freely pass therethrough. The battery having an air-permeable case according to the present invention includes: a stack formed by stacking a plurality of cells in which electrodes are formed; and a case enclosing the stack of the cells, wherein the case has wall surfaces in which a plurality of holes are formed so that an area thereof the hole is at least half of an area of the wall surface. Particularly, the case may include wall surfaces formed in a mesh structure.

Description

BATTERY HAVING AIR-PERMEABLE CASE

The present invention relates to a battery having an air-permeable case.

A battery is mainly divided into a primary battery and a secondary battery. Here, the primary battery, may not be reused after being used once since it uses an irreversible reaction to generate electricity, for example, a dry cell, a mercury battery, a Volta battery, or the like, that are generally used. In addition, the secondary battery may be reused by being charged after being used since it uses a reversible reaction, for example, a lead acid battery, a lithium ion battery, a Ni-Cd battery, or the like. FIG. 1 is a conceptual view showing a structure of a general lithium ion battery which is one of the secondary batteries. The lithium ion battery and a lithium ion polymer battery have the same structure as each other except for a state (liquid/solid) of an electrolyte. In addition, materials of the electrolyte or electrodes may be slightly different from a material described in FIG. 1 according to the kind of battery. As shown in FIG. 1, the lithium ion battery is configured to include an anode 1 generally made of carbon and a cathode 2 generally made of a lithium compound, an electrolyte 3 positioned between the anode and

cathode

1 and 2, and an electric wire 4 connecting the anode 1 and the cathode 2 to each other. Lithium ions in the electrolyte 3 move to the anode 1 at the time of charging and move to the cathode 2 at the time of discharging, and excess electrons are discharged or absorbed in each electrode, thereby causing a chemical reaction. The electron flows in the electric wire 4 in this process, and as a result, electric energy is generated. Although the case of the lithium ion battery is described here, in the case of other secondary batteries, the basic principle and structure are the same as those of the lithium ion battery except that materials used as the electrode or the electrolyte are changed. That is, the secondary battery is generally configured to include the anode 1, the cathode, 2, the electrolyte 3, and the electric wire 4, as described above.

Here, the secondary battery may be configured to include one anode 1, one cathode 2, one electrolyte 3, and one electric wire 4, but more generally, be formed by connecting a plurality of unit cells 10 including one anode 1, one cathode 2, one electrolyte 3, and one electric wire 4 to each other. That is, the plurality of unit cells 10 as described above are filled in a secondary battery pack. Each of the unit cells 10 are electrically connected to each other.

Generally, the secondary battery includes the plurality of unit cells and has a shape in which a pair of external terminal taps connected to electrodes of each of the cells (that is, a tap configured of a pair of one anode connected to the anode of each of the unit cells and one cathode connected to the cathode of each of the unit cells per one battery to serve as an electrode) is exposed to the outside. Generally, a plurality of secondary batteries as described above rather than a single secondary battery are connected to each other to form a battery as a single pack.

Meanwhile, when power is generated in the cell, heat by an electrochemical reaction may be generated, and in the case in which this heat remains in the cell as it is, a temperature of the cell may be increased, such that operation conditions of the cell may be deteriorated, thereby reducing power generation efficiency. Particularly, a support member such as a case fixing the cell, or the like, necessarily encloses a large portions of a surface of the cell, which may block the heat generated from the cell from being smoothly discharged to the outside, thereby deteriorating cooling performance of the cell.

FIGS. 2A and 2B show various structures for heat radiation or the cooling of the cell according to the related art. FIG. 2A shows a structure of a middle and large-sized battery pack disclosed in Korean Patent Laid-Open Publication No. 2009-0000313 (hereinafter, referred to as the related art 1). The related art 1 discloses a structure of the middle and large-sized battery pack in which a refrigerant passage is formed in a housing enclosing an outer surface of a battery cell stack, such that the refrigerant moves along the passage in which the cooling may be effectively performed to effectively cool the cell. In addition, FIG. 2B shows a device for cooling a battery for a vehicle disclosed in Korean Patent Laid-Open Publication No. 2010-0059083 (hereinafter, referred to as the related art 2). The related art 2 discloses the device for cooling a battery for a vehicle capable of improving cooling performance by changing shapes of an inlet and an outlet of the battery case to relatively increase flow resistance of cooling air flowing to a central portion of the battery. Both of the

related arts

1 and 2 have an air-cooling type cooling structure using the air as a medium to absorbing the heat of the battery. However, as described above, since it is not actually easy to allow the air to pass due to the case in this air cooling structure, there is some limitation in the cooling performance of the air-cooling type cooling technology.

In order to overcome this problem, a water-cooling type cooling technology using cooling water, or the like, has been used, but there is more limitation in designing the refrigerant passage than in the case of using the air, and in the case in which the cooling water is leaked, many problems may be generated. Therefore, a battery structure capable of having a cooling efficiency higher than that of the related art even while using the more stable air-cooling type cooling structure has been continuously demanded by those skilled in the art.

[Related Art Document]

[Patent Document]

1. Korean Patent Laid-Open Publication No. 2009-0000313 (Middle and Large Sized Battery Case)

2. Korean Patent Laid-Open Publication No. 2010-0059083 (Device for Cooling Battery for Vehicle)

An object of the present invention is to provide a battery having an air-permeable case capable of increasing cooling performance through air by having the air-permeable case allowing air to freely pass therethrough while limiting passage of moisture and foreign material.

In one general aspect, the present invention provides a battery having an air-permeable case including: a stack formed by stacking a plurality of cells in which electrodes are formed; and a case enclosing the stack of the cells, wherein the case has wall surfaces in which a plurality of holes are formed so that an area thereof is at least half of an area of the wall surface. Particularly, the case may have the wall surface formed in a mesh structure.

The case may be formed so that the wall surface thereof is covered with a water-proof material made of a fabric having a water-proof property and air-permeability.

As an embodiment, the case may have a rectangular parallelepiped shape in which the wall surface is made of a plate. In the case, the holes may be formed in at least four surfaces among six surfaces of the case. The plate may be made of a metal material or a plastic material.

As another embodiment, the case may have a rectangular parallelepiped shape in which each edge thereof is configured of frames and include a mesh material provided so as to be fixed and supported by the frame. In the case, the mesh material may be provided in at least four surfaces among six surfaces of the case. The frame may be made of a metal material or a plastic material. The mesh material may be made of a metal material or a plastic material.

As set forth above, according to the present invention, in a battery including a stack formed by stacking a plurality of cells and a case enclosing the stack, the case is formed so as to allow air to easily pass therethrough, such that air-cooling performance may be significantly increased as compared to the related art. More specifically, in the battery according to the present invention, a plurality of holes are formed in the wall surfaces of the case, and particularly, the wall surfaces are formed in the mesh structure, such that the air may more freely flow as compared to the related art to improve the air-permeability, thereby significantly increasing the air-cooling efficiency. According to the exemplary embodiment of the present invention, the water-proof materials having both the air-permeability and the water-proof property such as a cortex, or the like, covers holes of wall surfaces of the case, such that the air-permeability may also be increased while maintaining the water-proof property.

Further, according to the present invention, the plurality of holes are formed in the wall surface, such that the weight of the case may be significantly reduced as compared to the related art, thereby reducing a weight of the battery.

The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

FIG. 1 is a view showing a general structure of a lithium ion battery;

FIGS. 2A and 2B are views showing examples of a battery having an air-cooling type cooling structure according to the related art;

FIGS. 3 and 4 are views showing a battery according to exemplary embodiments of the present invention; and

FIG. 5 is a view showing a battery according to another exemplary embodiment of the present invention.

**Detailed Description of Main Elements**

100: Battery

110: Stack 111: Cell

120: Case 121: Hole

122: Water-proof material

Hereinafter, a battery having an air-permeable case according to an exemplary embodiment of the present invention having the above-mentioned configuration will be described in detail with reference to the accompanying drawings.

FIGS. 3 and 4 are views showing the battery according to the exemplary embodiments of the present invention. As shown in FIG. 3, the battery 100 according to the exemplary embodiment of the present invention is basically configured to include a stack 110 formed by stacking a plurality of cells 111 in which electrodes are formed and a case 120 enclosing the stack 110 of the cells 111, similarly to a battery according to the related art. According to the present invention, a structure of the case 120 is improved, such that air-permeability to the stack 110 of the cells 111 is improved, thereby making it possible to increase air-cooling performance of the air-cooling type battery.

According to the present invention, the case 120 has wall surfaces in which a plurality of holes 121 are formed, wherein an area of the hole 121 is at least half of an area of the wall surface. According to the present invention, a lot of holes 121 are formed in the wall surface of the case 120 so that area of the holes 121 is at least half of the area of the wall surface.

FIG. 3 shows the embodiment in which the case 120 forms an enclosure having a shape similar to that of the case according to the related art except that a lot of holes 121 are bored through the wall surface thereof. The case 120 having this shape may be easily manufactured by forming the holes 121 in a plate forming the wall surface of the case 120 through press-processing, or the like.

A detailed description of the embodiment of FIG. 3 will be provided as follows. The case 120 is formed so as to receive the stack 110. Here, since the stack 110 has an approximately rectangular parallelepiped shape, the case 120 is formed in a rectangular parallelepiped shape so as to receive the stack 110 in the embodiment of FIG. 3. In this case, the holes 121 may be formed in at least four surfaces among six surfaces of the case 120 as shown in FIG. 3. As described above, since the hole 121 formed in the case 120 may be manufactured by performing the press-processing on the plate, the plate forming the case 120 may be made of a material having rigidity appropriate for performing press-processing, that is, a metal material, a plastic material, or the like.

FIG. 4 shows the embodiment in which the wall surface of the case 120 particularly formed in a mesh structure. As described above, the wall surface is formed to have the lattice mesh structure, such that air-permeability may be significantly increased as compared to the related art. In this case, each of the meshes forming the wall surface may correspond to the holes 121.

A detailed description of the embodiment of FIG. 4 will be provided as follows. Similarly to the embodiment of FIG. 3, the case 120 is formed in a rectangular parallelepiped shape so as to receive the stack 110. Here, in the embodiment of FIG. 4, in the case in which the case 120 has the wall surface formed in the mesh structures rather than the holes, the case 120 may have a structure in which a basic framework of the case 120, that is, a frame has a rectangular parallelepiped shape and the mesh material is fixed to and supported on the frame, as shown in FIG. 4. Also in this case, at least four wall surfaces among six wall surfaces of the case 120 may be formed in the mesh structure as shown in FIG. 4. In the embodiment of FIG. 4, the frame configuring the framework of the case 120 may be made of a material having rigidity appropriate for stably supporting the mesh material, that is, a metal material, a plastic material, or the like. Further, the mesh may be made of a metal mesh, a plastic mesh, or the like.

As described above, in the battery 100 according to the present invention, the holes 121 having a significantly wide area are formed in the wall surface of the case 120 as compared to the related art, such that it may be significantly easy to introduce and discharge the air as compared to the battery according to the related art. In addition, since the heat discharged in the cell 111 may be absorbed by the newly introduced air and the air absorbing the heat may be easily discharged, the cooling efficiency by air-cooling may be significantly increased as compared to the related art. Therefore, a load such as a fan used to effectively blow the air between the cells 111 (that is, used to generate cooling air) in the art may be also significantly reduced, which may improve energy consumption efficiency.

Further, as described above, in the present invention, a lot of holes 121 are formed in the wall surface of the case 120, thereby making it possible to reduce a weight of the case 120 as compared to the related art. Particularly, a field in which this battery 100 is used is a fuel cell vehicle or a hybrid vehicle, wherein in this vehicle, it is one of the very important design improvement factors to reduce the weight of various parts in order to improve fuel efficiency. In this case, in the battery 100 according to the present invention, a lot of holes 121 may be formed in the case 120 so that the area of the holes 121 is at least half of the area of the wall surface. That is, a large amount of materials of the case 120 is removed by the holes 121, which directly reduces the weight of the case 120.

That is, the case 120 of the present invention may significantly reduce the weight (by removing a large amount of the material forming the case 120) in addition to maximizing the air-permeability. Therefore, in the case in which the battery 100 according to the present invention is used in the fuel cell vehicle, the hybrid vehicle, or the like, ultimately, the fuel efficiency of the vehicle may be significantly improved.

Although shapes in which upper and lower surfaces of the case 120 are omitted are shown in FIGS. 3 and 4, and FIG. 5 to be described below, in order to simplify the drawings, actually the case 120 should have the upper and lower surfaces and the holes 121 should be also formed in the upper and lower surface of the case 120.

As the battery according to another embodiment of the present invention, a structure in which a water-proof material 122 made of a fabric having a water-proof property and air-permeability covers the wall surface of the case 120 is shown in FIG. 5.

As described above, when the wall surface of the case 120 has the holes 121 having the wide area such as the case in which the wall surface of the case 120 have the mesh structure, or the like, air-permeability may be clearly maximized. However, in this case, there is a risk that materials having a negative effect on operation of the cell 111 such as moisture, foreign materials, or the like, may be introduced through the holes 121.

In order to remove this risk, according to the present invention, the wall surface of the case 120 may be covered with the water-proof material 122 made of the fabric having the water-proof property and air-permeability. As the water-proof material 122, a well-known material such as the cortex, or the like, having the above-mentioned property may be used. Here, although the cortex may be used by way of example of the water-proof material 122, the present invention is not limited thereto, but any material may be used as the water-proof material 122 as long as the material simultaneously has the a water-proof property so as to block moisture and foreign materials and air-permeability so as to allow the air to pass therethrough.

As described above, the water-proof material 122 covers the case 120, such that introduction of moisture and foreign materials into the stack 110 of the cells 111 may be effectively prevented and the air-permeability may be mostly maintained as it is, thereby making it possible to maintain the improved cooling performance as it is.

The present invention is not limited to the above-mentioned exemplary embodiments but may be variously applied, and may be variously modified by those skilled in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims.

According to the exemplary embodiments of the present invention, in a battery including a stack formed by stacking a plurality of cells and a case enclosing the stack, the case is formed so as to allow air to easily pass therethrough, such that air-cooling performance may be significantly increased as compared to the related art. In addition, according to the present invention, water-proof materials having both air-permeability and water-proof property such as a cortex, or the like, covers holes of wall surfaces of the case, such that the air-permeability may also be increased while maintaining the water-proof property. Further, according to the present invention, a plurality of holes are formed in the wall surface, such that a weight of the case may be significantly reduced as compared to the related art, thereby making it possible to reduce a weight of the battery.

Claims

A battery having an air-permeable case comprising:

a stack formed by stacking a plurality of cells in which electrodes are formed; and

a case enclosing the stack of the cells,

wherein the case has wall surfaces in which a plurality of holes are formed so that an area thereof is at least half of an area of the wall surface.
The battery having an air-permeable case of claim 1, wherein the case has the wall surface formed in a mesh structure.
The battery having an air-permeable case of claim 1, wherein the case is formed so that the wall surface thereof is covered with a water-proof material made of a fabric having a water-proof property and air-permeability.
The battery having an air-permeable case of claim 1, wherein the case has a rectangular parallelepiped shape in which the wall surface is made of a plate.
The battery having an air-permeable case of claim 4, wherein in the case, the holes are formed in at least four surfaces among six surfaces of the case.
The battery having an air-permeable case of claim 4, wherein the plate is made of a metal material or a plastic material.
The battery having an air-permeable case of claim 2, wherein the case has a rectangular parallelepiped shape in which each edge thereof is configured of frames and includes a mesh material provided so as to be fixed and supported by the frame.
The battery having an air-permeable case of claim 7, wherein in the case, the mesh material is provided in at least four surfaces among six surfaces of the case.
The battery having an air-permeable case of claim 7, wherein the frame is made of a metal material or a plastic material.
The battery having an air-permeable case of claim 7, wherein the mesh material is made of a metal material or a plastic material.