KR100765966B1 - Collapsible Metal-Air Battery - Google Patents

Abstract

The collapsible metal air battery according to the present invention includes a pair of metal frames, a rubber housing bonded to the left and right sides and the bottom of the pair of metal frames, a separator and an air anode bonded to the outer surface of the metal frame, The unit cell is composed of a plate-shaped metal fuel electrode inserted into the pair of metal frames. When connecting a plurality of such unit cells in series, a metal diffusion plate is inserted between the unit cells, and rubber bands are attached to the left and right sides of the cell. The present invention according to such a configuration is made by stacking the unit cells by connecting a plurality of unit cells in series, it is possible to fold it is very convenient to store or move. It is portable and has a small volume and weight, but in an emergency where electricity is needed, it can be expanded and water is added to obtain a large amount of electricity. When stored in a dry state, it can be stored for a very long time, so it is suitable for carrying in case of emergency.

Metal fuel cell, metal air battery, metal frame, air anode, hydrophobic film layer, metal fuel electrode

Description

Collapsible Metal-Air Battery

The present invention relates to a metal fuel cell, ie a metal air cell, which generates electricity by oxidizing aluminum and magnesium active metals using oxygen in the air.

In metal fuel cells or metal air cells, the cathode is generally used metals such as aluminum, magnesium, zinc or alloys thereof, and the electrolyte is a salt or alkaline aqueous solution. In general, a metal air battery has a large volume of water, which is an electrolyte solution, and at least 30% of the total volume is filled with an electrolyte solution.

When the size of the conventional metal air battery is small, there are a lot of button-type, they are in the form of a metal powder or a plate therein, in the case of a large size is a box-type fixed in size. In addition, in most conventional metal-air cells, the structure of the battery has a rigid structure so that the liquid electrolyte does not leak. Therefore, the conventional metal air battery is very inconvenient to transport because it is a rigid structure with a fixed size. In addition, since the unit cell voltage is low as 0.8 ~ 1.6 volt, it is more difficult to transport when a plurality of unit cells are configured in series to obtain a suitable high voltage. Furthermore, water must be uniformly injected into each unit cell, which causes the metal air battery to have a very complicated internal structure.

As one effort to reduce the weight and volume of a metal air cell in a dry, dewatered state, US Pat. No. 5,439,758 reported a flexible, collapsible air electrode bag. Although this type of battery allows the contents to be removed and folded to reduce storage volume and weight in the dry state, there are some problems in practical use. First, the hydrophobic membrane of the air anode can be easily peeled off. That is, there is a possibility that the hydrophobic film is separated from the carbon and nickel meshes. In addition, the use of chemical adhesives may result in incomplete sealing after multiple uses. To overcome these problems, a mechanical grip and a better bonding method are needed to hold the edges of the bonding area and air electrode. Secondly, covering one side of the metal fuel electrode with an insulating plate can reduce the electrochemical effective area. Therefore, a structure in which one cathode plate is surrounded by two air anodes is very advantageous for producing a lot of power. Third, the structure or material is not strong enough for repeated use. Especially at low temperatures like -20 ℃, the vinyl becomes hard and can be damaged.

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

A front view and a cross-sectional view of a portable metal air battery are shown in FIG. 1, a pair of metal frames 10, a rubber housing 20 bonded to the left and right sides and bottom surfaces of the pair of metal frames 10, and The separator 30 and the air anode 40 adhered to the outer surfaces of the pair of metal frames 10, and the plate-shaped metal fuel electrodes 50 inserted into the pair of metal frames 10. It is composed of one battery unit. The first step of forming a rubber housing 20 on the metal frame 10 by curing for 150 to 290 ℃ 40 to 210 seconds to configure such a unit cell; Attaching a separator (30) to an outer surface of the metal frame (10); A third step of attaching the air anode 40 to the upper portion of the separator 30; After the air cathode 40 is attached, the bending part 11 of the metal frame 10 is pressed by a press. In the fourth step, it is more preferable that the metal insert 60 is inserted into the battery to compress the bent portion 11 of the metal frame 10.

Here, the metal frame 10 is made of nickel or nickel coated stainless plate resistant to brine, and has a thickness of 0.1 to 0.3 mm, and is used to seal the rubber housing 20 by connecting the air cathode 40 to it. will be. As shown in Fig. 2A, the metal frame 10 is a rectangular frame made of a union jack shaped grating or perforated plate, and the four edges are bent at 90 degrees to have a bent portion 11. In addition, the four vertices 12 of the metal frame 10 are cut at an angle of 45 degrees so that they do not overlap each other when the bent portion 11 is folded, and drawing to a depth of 0.8 to 1.2 mm so that the rubber resin is formed during the rubber molding. 10) to prevent penetration into the interior.

When molding the rubber housing 20 on the left and right sides and the bottom of the metal frame 10, the adhesive is applied in the mold and then heat and pressure is applied to make the adhesion well. In the case of injection molding or hot pressing, the surface of the metal frame 10 is formed. Sandblasting to improve adhesion. In this case, when curing is performed at 150 to 290 ° C., more preferably at 160 to 280 ° C., 40 to 210 seconds, and more preferably 50 to 200 seconds, the rubber housing 20 to the metal frame 10 may be formed by a rubber-metal bonding method. Are glued. 3 and 4, a pair of rubber tubes 21 are provided on the lower left and right sides of the rubber housing 20. As shown in FIG. After that, the separator 30 and the air cathode 40 are sequentially attached to the outer portion of the metal frame 10.

The air anode 40 is one surface is coated with a carbon layer 41, the other surface is a nickel mesh 43 is coated with a hydrophobic film layer 42, the manufacturing method is activated carbon powder is a fluororesin adhesive poly Tetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF, fluorone resin adhesive) is mixed, heat and pressure is applied to the nickel mesh (43), and then the porous hydrophobic film is attached to the nickel mesh surface. To prepare.

When attaching the separator 30 and the air cathode 40 to the metal frame 10, the separator 30 is attached to the surface of the air anode 40 to which the carbon layer 41 is coated. At this time, the adhesive is first coated on the edge of the surface on which the hydrophobic film of the air cathode is applied, thereby preventing water from leaking out after assembling. Thereafter, the bent portion 11 of the metal frame 10 is pressed by a press, and the metal insert 60 is inserted into the unit cell and pressed by a press to prevent damage to the air anode and to complete the deformation of the metal frame. More preferred. After pressing the bent portion 11 of the metal frame 10 by pressing, the metal insert 60 is removed.

The rubber housing 20 is made of nitrilebutadiene rubber (NBR), ethylene propylene diene monomer rubber (EPDM), or chloroprene rubber (CR). Since the side of the battery is made of rubber like this can be folded.

The separator 30 is about 0.2 mm thick and is made of a porous nonwoven fabric made of polypropylene.

Metal fuel electrode 50 in the present invention is a plate-shaped alloy consisting of aluminum and magnesium, the thickness is 0.5 ~ 4.0mm. These metals do not need to be in sealed containers because they react in salt or weakly alkaline solutions that are harmless to the body. In addition, an open structure is more suitable than a closed type due to hydrogen generation due to self-corrosion reaction.

When the plurality of unit cells as described above are used in series, as shown in FIG. 7, the air diffusion plate 70 is inserted between the unit cells, and the rubber bands 80 are disposed on the upper and lower sides of the battery. Are glued. It is provided with a separate water tank (90) formed with a connection rubber tube 91, the inside of the water tank (90) includes a salt bag (92) made of a porous non-woven fabric incorporating electrolyte salt. The water tank 90 is made of plastic or rubber, and the air diffusion plate 70 has a thickness of 2 to 6 mm, a porosity of 90%, and a pore density of 20 to 40 ppi (pores per inch). When water is supplied as the electrolyte solution into the battery, the connection rubber tube 91 formed in the tank is connected to the rubber tube 21 provided in the rubber housing 20 so that the electrolyte solution is injected through the tube. . At this time, the passage in which the water is injected is configured in a zigzag manner so that the water is continuously filled. Accordingly, when water is injected, the salt of the salt bag 92 inherent in the water tank 90 is dissolved and supplied to the battery.

1 is a front view and a sectional view of a unit cell of the present invention;

Fig. 2A is a front view of a metal frame having a grate inside in the present invention;

2B is a front view of a metal frame having a perforated plate therein according to the present invention;

3 is a process chart showing a manufacturing process of a unit cell of the present invention;

4 shows a second process of FIG. 3;

5 is an enlarged cross-sectional view of a portion of a unit cell according to Embodiment 1;

6 is an enlarged cross-sectional view of a portion of a unit cell according to Embodiment 2;

7 is a view showing a state in which a plurality of unit cells of the present invention connected;

8A is a view showing a folded state after connecting the unit cells of the present invention in series,

Figure 8B is a view showing an expanded state after connecting the unit cells of the present invention in series.

<Code Description of Main Parts of Drawing>

10: metal frame 11: bend

12: vertex 13: hole

20: rubber housing 21: rubber tube

30: separator 40: air anode

41: carbon layer 42: hydrophobic film layer

43: nickel mesh 44: airtight film

50; metal fuel electrode 60; metal insert

70: air diffusion plate 80: rubber band

90: water tank 91: connection rubber tube

92: salt bag

Example 1

In the present invention, the metal frame 10 has a bent portion 11 bent 90 degrees in four sides of the square in a rectangular rectangular window frame or perforated plate. FIG. 5 shows an enlarged cross-sectional view of a part of a unit cell manufactured using a metal frame 10 having a union jack shaped grate as shown in FIG. 2A. The separator 30 is attached to the metal frame 10, and then the air anode 40 coated with the carbon layer 41 and the hydrophobic film layer 42 is attached. Here, the nickel mesh 43 of the air anode 40 is inherent between the carbon layer 41 and the hydrophobic film layer 42 and serves to transfer current. Before the metal frame 10 is pressed by a press, an adhesive is applied to the edge of the hydrophobic film layer 42 of the air cathode 40 so that a sealing film 44 is formed and no leakage occurs. Thereafter, the bent portion 11 of the metal frame 10 is pressed by a press.

Example 2

In the present invention, the metal frame 10 is a quadrangular rectangular jack frame or perforated plate, and the four sides of the rectangle are bent at 90 degrees to have the bent portion 11. FIG. 6 shows an enlarged cross-sectional view of a part of a unit cell manufactured using a metal frame 10 made of a perforated plate having small holes 13 as shown in FIG. 2B. The inside of the metal frame 10 is a perforated plate, that is, the inside in which the small holes 13 having a diameter of about 1 mm are closely drilled as a nickel mesh. These holes 13 are formed by perforation in a press, and are filled with activated carbon powder, which is the same material as the carbon layer 41, and becomes a passage through which air or oxygen flows. In the same manner as in Example 1, an adhesive is applied to the edge of the hydrophobic film layer 42 to form the sealing film 44. This type of air anode can reduce production costs and reduce the thickness of metal air cells.

Example 3

The metal frame 10 is made through a work that is pressed and cut in a press. The metal frame 10 used was stainless steel plate (316code) and nickel plate (99.8% purity), and the surface was polished by sand blasting before applying rubber adhesive to the edge of the metal frame 10. Put a pair of metal frame (10) in a rubber mold and cured at 50 kg / ㎠ pressure for 60 seconds at 180 ℃ to connect the rubber housing to a pair of nickel frame. The air anode 40 used O-Cat of Evionyx Inc. of the United States. 5 and 6 were bonded to the metal frame 10 together with the polypropylene separator 30. No leakage of water was observed even after prolonged use for two weeks.

Example 4

As shown in Figs. 6 and 7, a metal frame 10 of 200 mm x 105 mm x 0.2 mm size is manufactured in a press. Using a carbide punch, holes 1 mm in diameter were drilled at an interval of 1.5 mm to an inside 180 mm x 85 mm size. As the hydrophobic film layer, a product made by W.L.Gore and Associates Tex, which is called an air diffusion film, was used and adhered to the nickel plate. Activated carbon powder having a specific surface area of 1000 m 2 / g was used in a mixture of 20% solids PVDF and 80% NMP (n-methyl-2-pyrrolidone) in a polyvinylidene fluoride (PVDF) solution. As a weight ratio, a mixture of activated carbon 40% and 60% vinyl fluoride resin solution was applied to the perforated nickel plate 180 mm x 85 mm. Carbon-coated surface of the nickel frame was molded for 1 minute at 200 ~ 240 ℃ at a pressure of 10kg / ㎠. Air anode is pressed to the edge portion of the press to make as shown in Figure 6 and then rubber molding in a rubber molding die. The conditions are the same as in Example 3. The unit cell manufactured as described above was robust and exhibited proper characteristics, and no water leakage was observed.

Example 5

The cells were tested in 12% sodium chloride solution, 12% salt and 1% caustic soda solution. An air electrode assembly made in Example 3 was used. The aluminum electrode used was an alloy containing 2.5% magnesium. In addition, the magnesium electrode used was an alloy of 4% aluminum and 0.5% zinc. The thickness was 1 mm, the height was 90 mm, and the width was 180 mm. In the stacked cell with 12 unit cells and 13 air diffuser plates, the cell in which the metal anode was removed and folded was 125 mm in length and 310 mm in the unfolded state.

In the case of using aluminum electrodes in series, the results were 30 to 36 watts in 12% salt and 60 to 99 watts in 12% salt and 1% caustic soda solution. When magnesium electrodes were used, an output of 80 to 120 watts was obtained in 12% brine, with a voltage of 14 to 17 volts.

Example 6

In the present invention, the electrolyte is made by dissolving the salt bag 92 in the water tank 90. The reaction products were oxides and hydrates of aluminum and magnesium, which were easily removed from the rubber housing. Approximately 250 hours of continuous testing and 10 recharge tests confirmed the stack cell's durability and no decrease in properties was observed.

Example 7

8A and 8B show that the present invention collapsible metal air battery has a collapsible characteristic. Since the filled solution is not harmful to the human body, users can remove the water inside and press it flat to reduce the size and weight when moving or storing. An air diffusion plate 70 may be provided between the unit cells to prevent the air electrode 40 from being excessively splashed out by the filled water. The air diffuser plate 70 has a porosity of 90% and a pore density of 10 to 40 ppi (pores per inch).

When the length of the folding direction is viewed, the folded state (Fig. 8A) is about 50% of the unfolded state (Fig. 8B). This is an excellent advantage of the collapsible metal air battery according to the present invention configured to be collapsible. The rubber band 80 is bonded to the left and right sides of the battery and serves to bind and hold the battery.

The collapsible metal air battery according to the present invention is made of a stack type battery by connecting a plurality of unit cells in series, so that the collapsible metal air battery can be folded and stored or moved very conveniently. It is portable and has a small volume and weight, but in an emergency where electricity is needed, it can be expanded and water is added to obtain a large amount of electricity. When stored in a dry state, it can be stored for a very long time, so it is suitable for carrying in case of emergency.

Claims (15)

A pair of metal frames, a rubber housing bonded to the left and right sides and the bottom of the pair of metal frames, a separator and an air anode bonded to an outer surface of the pair of metal frames, and inside the pair of metal frames A collapsible metal air battery comprising a unit cell comprising an inserted plate-shaped metal fuel electrode. The collapsible metal-air battery of claim 1, wherein the separator is a polypropylene nonwoven fabric. The collapsible metal-air battery according to claim 1, wherein the air cathode is a nickel mesh coated with a porous hydrophobic membrane on one surface and an activated carbon powder on the other surface. The collapsible metal-air battery according to claim 1, wherein the metal fuel electrode is a metal plate composed mainly of aluminum and magnesium. The collapsible metal-air battery according to claim 1, wherein the metal frame has a bent portion at which four edges are bent, and an inside thereof has a shape of a grate. The collapsible metal-air battery according to claim 1, wherein the metal frame has a bent portion at which four edges are bent, and the inside of the metal frame has a shape of a perforated plate. The metal frame of claim 5 or 6, wherein the vertex portions of the metal frame are cut at an angle of 45 degrees so that the metal frame does not overlap each other when the bent portions of the metal frame are folded, and the bent portions are drawn to a depth of 0.8 to 1.2 mm. One collapsible metal air battery. The collapsible metal-air battery according to claim 1, wherein the rubber housing is provided with a pair of rubber tubes on the lower left and right sides thereof. A first step of forming a rubber housing on a metal frame by curing at 150 to 290 ° C. for 40 to 210 seconds; Attaching a separator to an outer surface of the metal frame; The collapsible metal air battery of claim 1, wherein the collapsible metal air battery is manufactured by a third step of attaching an air anode to the upper part of the separator and a fourth step of pressing the bent portion of the metal frame by pressing after attaching the air anode. Manufacturing method. The method of manufacturing a collapsible metal-air battery according to claim 9, wherein the metal insert is inserted into the battery when the bent portion of the metal frame of the fourth step is pressed by a press. When the plurality of unit cells according to claim 1 in series, an air diffusion plate is inserted between the unit cells, the collapsible metal air battery, characterized in that the rubber band is bonded to the left and right sides of the battery. The collapsible metal-air battery according to claim 11, further comprising a water tank in which a rubber tube for connection is formed. The collapsible metal-air battery according to claim 12, wherein the water tank includes a salt bag made of a porous nonwoven fabric having electrolyte salt embedded therein. The collapsible metal-air battery according to claim 12, wherein the air diffusion plate has a porosity of 90% and a pore density of 10 to 40 ppi as a sponge. The collapsible metal-air battery according to claim 12, wherein the connecting rubber tubes are connected in a zigzag manner to the rubber tubes formed in the rubber housing so that the electrolyte is continuously injected.

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