KR20240010204A - gas discharge type zinc-air battery - Google Patents

Abstract

The present invention relates to a zinc-air battery in which a separator and a cathode electrode are sequentially stacked on an air electrode portion arranged so that air flowing in through an air hole formed on the bottom of the case can contact the case, and the case is opposed to the cathode electrode portion. At least one gas release hole is formed on the upper surface of the case to communicate with the outside, and a valve is installed on the upper surface of the case to open the gas release hole when the gas pressure exceeds a set standard. This gas-release type zinc-air battery provides the advantage of suppressing internal pressure increase and battery expansion by supporting the release of hydrogen gas generated internally.

Description

Gas discharge type zinc-air battery

The present invention relates to a gas-release type zinc-air battery, and more specifically, to a gas-release type zinc-air battery capable of improving sustainability of use by supporting the release of gases generated during use.

Zinc-air batteries have a much higher theoretical energy density (>1,086 Wh/kg) than lithium-based secondary batteries, and are attracting great attention as alternative energy storage devices for transportation devices such as electric vehicles and various portable electronic devices. Zinc-air batteries have been disclosed in various ways, including domestic registered utility model No. 20-0331899.

Unlike lithium secondary batteries, these zinc-air batteries use a zinc-based cathode and an aqueous electrolyte that are stable even when exposed to the atmosphere, and use air in the atmosphere as fuel for the anode to generate a discharge reaction, so short heat caused by external shock is generated. However, the risk of ignition or explosion is significantly low, making it suitable as a power source for body-worn Internet of Things (IoT) devices. In addition, as the wearable market has recently expanded, the demand for flexible batteries has increased significantly. The high energy density of zinc-air batteries, the ease of converting components into an all-solid state, and the simple stacking Due to the stack structure, research on flexible zinc-air batteries is actively underway.

On the other hand, when a zinc-air battery is stored, a corrosion reaction accompanied by hydrogen generation occurs at the cathode, which increases the internal pressure of the battery and may cause expansion or leakage of the battery. In addition, during battery operation, a hydrogen generation reaction occurs on the surface of a new cathode by forming zincate ions at the end of discharge, and during overcharging, a new metallic zinc surface is created through a reduction reaction on the surface of the cathode and hydrogen is generated. This may be accompanied by gas generation, which may result in an increase in the internal pressure of the battery.

Therefore, there is a need for a method to suppress the increase in internal pressure and expansion of the battery due to hydrogen gas generated internally.

The present invention was created to solve the above requirements, and its purpose is to provide a gas-release type zinc-air battery that can suppress the increase in internal pressure and expansion of the battery due to hydrogen gas generated internally.

In order to achieve the above object, the gas-release type zinc-air battery according to the present invention is sequentially stacked with a separator and a negative electrode portion on the air electrode portion arranged so that the air flowing in through the air hole formed on the bottom of the case can be contacted. In the zinc-air battery, at least one gas release hole is formed on the upper surface of the case opposite the cathode electrode portion and is in communication with the outside, and the gas release hole is formed on the upper surface of the case at a pressure higher than a set reference gas pressure. When this happens, it is provided with a valve mounted to be open.

According to one aspect of the present invention, the valve includes a first seat joined to the upper surface of the case and having an opening and closing hole communicating with the gas discharge hole; The opening and closing hole is covered on the upper surface of the first sheet, and when the gas pressure applied through the opening and closing hole is higher than the set standard gas pressure, the first passage is opened, and when it is lower than the reference gas pressure, the first passage is connected to the first sheet. and a second opening and closing sheet joined to the first sheet around the first passage to close the opening and closing hole in close contact.

In addition, the first sheet and the second opening/closing sheet are preferably made of synthetic resin material, and each has a thickness of 0.01 to 1 mm.

In addition, the first and second electrodes are formed on the upper and lower surfaces of the case to be exposed to the outside, and when the off-gassing type zinc-air battery and the air hole are arranged to face each other, they are connected to each other while forming an air inflow space. To make this possible, among the first and second regions that divide the bottom of the case into two, a plurality of first coupling pipes having pin insertion grooves are formed in the first region, and in the second region, a plurality of first coupling pipes are formed in the pin insertion grooves. A plurality of fitting pins that are inserted and fitted are formed, and the first electrode is formed in the center of the area corresponding to the second area.

In addition, the second electrode is formed at the center of the first area corresponding to the position of the first electrode when the second area is rotated 180 degrees, and the case forms an upper surface where the gas discharge hole is formed. A first plate-shaped portion, a first vertical jaw portion extending downward from an edge of the first plate-shaped portion, and an inner diameter extending from the bottom of the first vertical jaw portion to be larger than the first vertical jaw portion and extending vertically downward. an upper case having an extended second vertical jaw portion; A second plate-shaped portion forming a bottom surface in which a plurality of air holes are spaced apart from each other extends upward from the edge of the second plate-shaped portion to be coupled to the upper case, and enters the inside of the second vertical jaw portion. a lower case having a third vertical jaw portion extending to interfere with the first vertical jaw portion and having insertion holes formed in the third vertical jaw portion to be spaced apart from each other; The sheet plate-shaped element that is tightly coupled to the inside of the lower case and forms the air electrode unit is formed in a rectangular frame shape so as to fit closely along the inner edge of the lower case, and the third is attached to the outer surface opposite to the inner side of the lower case. It is provided with a gasket in which a hook is formed to protrude and is fitted into an insertion hole formed in the vertical jaw portion.

The gas-release type zinc-air battery according to the present invention provides the advantage of suppressing internal pressure increase and battery expansion by supporting the release of hydrogen gas generated internally.

1 is a perspective view showing a gas-release type zinc-air battery according to the present invention;
Figure 2 is a cross-sectional view of the gas-release type zinc-air battery of Figure 1;
Figure 3 is an exploded cross-sectional view of the gas-release type zinc-air battery of Figure 2;
Figure 4 is an exploded perspective view showing the case of the gas-release type zinc-air battery of Figure 1;
Figure 5 is an exploded and enlarged perspective view to explain the valve structure of Figure 1.

Hereinafter, a gas-release type zinc-air battery according to a preferred embodiment of the present invention will be described in more detail with reference to the attached drawings.

Figure 1 is a perspective view showing a gas-release type zinc-air battery according to the present invention, Figure 2 is a cross-sectional view of the gas-release type zinc-air battery of Figure 1, and Figure 3 is an exploded cross-sectional view of the gas-release type zinc-air battery of Figure 2. , and Figure 4 is an exploded perspective view showing the case of the gas-release type zinc-air battery of Figure 1.

1 to 4, the gas-release type zinc-air battery 100 according to the present invention includes a case 110, an air electrode portion 130, a separator 150, a negative electrode portion 170, and a valve 180. ) is provided.

The case 110 functions to protect the zinc-air battery 100 and is made of synthetic resin.

A plurality of gas discharge holes 111 in communication with the outside are formed on the upper surface of the case 110 opposite the cathode electrode unit 170, which will be described later, and on the lower surface opposite the air electrode unit 130, air is introduced. A number of air holes 115 that allow are formed. Of course, unlike the example shown, a single gas discharge hole 111 may be formed on the upper surface of the case 110 to communicate with the outside.

In addition, on the upper and lower surfaces of the case 110, a first electrode 191, which serves as a cathode, and a second electrode 192, which serves as an anode, are formed to be exposed to the outside, and an off-gassing type zinc-air battery (not shown) is formed. When the and air holes 115 are arranged facing each other, a first area (a1) and a second area (a1) that divide the bottom of the case 110 into two to enable interconnection while forming an air inflow space in a spaced state In a2), in the first area (a1), a plurality of first coupling pipes 121 having pin insertion grooves 121a are formed so as to protrude downward, and in the second area (a2), the pin insertion grooves 121a are formed. A plurality of fitting pins 122 that are inserted and fitted are formed.

Additionally, the first electrode 191 is formed in the center of the area corresponding to the second area (a2).

Case 110 is structured to have an upper case 112, a lower case 114, and a gasket 118 for ease of assembly.

The upper case 112 includes a first rectangular plate-shaped portion 112a in which a gas discharge hole 111 is formed to form the upper surface of the case 110, and a first plate-shaped portion 112a extending downward from the edge of the first plate-shaped portion 112a. A first vertical jaw portion (112b) and a second vertical jaw portion (112c) extending from the bottom of the first vertical jaw portion (112b) to have an inner diameter larger than the first vertical jaw portion (112b) and extending vertically downward. It has a structure that has On the ceiling surface opposite the first plate-shaped portion 112a of the upper case 112, spacing guide pins 112d extending downward are formed to be spaced apart from each other to guide the cathode electrode portion 170 to be supported in a spaced state. there is.

In addition, a through hole 113 for the first electrode is formed in the first plate-shaped portion 112a of the upper case 112 so that the first electrode 191 can be mounted to be exposed to the outside.

The lower case 114 is accommodated within the second vertical jaw portion 112c of the upper case 112 and is formed in a size that can interfere with the first vertical jaw portion 112b to block entry.

When dividing the lower case 114, a plurality of air holes 115 are formed to be spaced apart from each other so that they can be coupled to the second square plate-shaped portion 114a forming the bottom of the case 110 and the upper case 112. A structure having a third vertical jaw portion 114b that extends upward from the edge of the second plate-shaped portion 114a and enters the inside of the second vertical jaw portion 112c, but extends to interfere with the first vertical jaw portion 112b. It is written as .

A through hole 117 for the second electrode is formed in the second plate-shaped portion 114a of the lower case 114 so that the second electrode 192 can be exposed to the outside.

The previously described first coupling pipe 121 and fitting pin 122 are formed to protrude from the bottom of the second plate-shaped portion 114a of the lower case 114.

In addition, the third vertical jaw portion 114b of the lower case 114 has a plurality of square insertion holes 114c spaced apart from each other along the sides into which the hook 118b of the gasket 118, which will be described later, can be inserted and locked. It is formed.

The gasket 118 is tightly coupled to the inside of the lower case 114, forming a sheet plate-shaped element in which the air electrode unit 130 and the separator 150 are integrated into a second plate shape along the inner edge of the lower case 114. The frame body 118a is formed in a square frame shape to be in close contact with the portion 114a, and is inserted into the outer surface opposite to the inside of the third vertical jaw portion 114b of the lower case 114 of the frame body 118a when assembled. It is structured to have a hook 118b that protrudes to fit into the hole 114c.

In the assembled state, the space between the lower case 114 and the upper case 112 is sealed with a sealing material.

The air electrode unit 130 is a square sheet on the bottom of the lower case 114 so that air flowing in through the air hole 115 formed in the second plate-shaped portion 114a, which is the bottom of the case 110, can be contacted. It is arranged in a complex form.

The air electrode unit 130 has a structure in which a hydrophobic film 131, a catalyst layer 132, and a diffusion layer 132 are sequentially stacked.

The hydrophobic membrane 131 is a membrane formed of a material that allows air to pass through and blocks moisture from entering from the outside, and is formed of a hydrophobic binder such as polytetrafluoroethylene (PTFE).

The catalyst layer 132 is a layer that generates hydroxide ions by reacting with oxygen in the air, and may be composed of a catalyst, a carrier supporting the catalyst, and a conductor. As an example, the catalyst layer 132 may be formed by combining various known materials, such as activated carbon, carbon nanofibers, manganese oxide, platinum oxide, carbon black as a conductor, and a Teflon binder.

The diffusion layer 133 provides a flow path for oxygen and functions as a current collector, and can be formed in various structures, such as a structure in which activated carbon is pressed onto a metal screen made of nickel.

Of course, the air electrode unit 130 may have various known structures different from the exemplified structure.

The second electrode 192 extending downward from the bottom of the air electrode unit 130 is located in the first area (a1) corresponding to the position of the first electrode 191 when the second area (a2) is rotated 180 degrees. It is formed in the center.

The separator 150 functions to isolate the air electrode unit 130 and the cathode electrode unit 170 and may be made of an ion-permeable material that allows hydroxide ions to pass through, for example, polypropylene.

The separator 150 is preferably integrally coupled with the air electrode portion 130, and in the example shown, it is integrally joined in the form of a sheet on the metal mesh 132.

The cathode electrode unit 170 is disposed on the separator 150.

The cathode electrode unit 170 is a part that functions as a cathode of the zinc-air battery 100, and may be formed by zinc powder and electrolyte solution formed in a gel state by a binder.

Of course, the cathode electrode unit 170 can be formed in a pack form by accommodating a cathode mixture consisting of an electrolyte, a gelling agent, a binder, and zinc.

The valve 180 is coupled to the upper surface of the case 110 and opens the gas discharge hole 111 when the set reference gas pressure is higher. This will be described with reference to FIG. 5.

The valve 180 is formed of a first seat 181 and a second opening/closing seat 183.

The first sheet 181 is a sheet extending in a strip shape and is joined to the upper surface of the case 110 and has an opening and closing hole 181a communicating with the gas discharge hole 111.

The second opening and closing sheet 183 covers the opening and closing hole 181a on the upper surface of the first sheet 181, and when the gas pressure applied through the opening and closing hole 181a exceeds the set reference gas pressure, the first passage 183a opens. If the pressure is less than the standard gas pressure, the periphery 183b of the first passage 183a is joined to the first sheet 181 so that the first passage 183a is in close contact with the first sheet 181 and closes the opening and closing hole 181a. It has a structured structure.

The second opening and closing sheet 183 is in the shape of a square sheet and has a larger size than the opening and closing hole 181a, and the peripheral portion indicated by reference numeral 183b, which is an area on both sides of the central portion forming the first passage 183a, is the first opening and closing sheet 183. The sheet 181 is bonded to a joint portion indicated by reference numeral 181b.

This second opening/closing sheet 183 opens the opening/closing hole (181a) when the first passage (183a) is above the standard gas pressure, and closes the opening/closing hole (181a) when the pressure is below the standard gas. It is in close contact with (181) and supports the release of gas generated from the cathode electrode unit 170 to the outside of the case 110.

Here, the first sheet 181 and the second opening/closing sheet 182 are made of synthetic resin material, and each has a thickness of 0.01 to 1 mm. If the thickness of the first sheet 181 and the second opening/closing sheet 182 is less than 0.01 mm, they can be opened even under a slight gas pressure to allow the inflow of external air, and if the thickness is more than 1 mm, the pressure required for opening becomes too high.

This valve 180 provides the advantage of suppressing an increase in internal pressure and expansion of the battery by supporting the release of hydrogen gas generated internally, even though the increase in the overall thickness of the zinc-air battery 100 is negligible.

110: Case 130: Air electrode unit
150: Separator 170: Cathode electrode part
180: valve

Claims (5)

In a zinc-air battery in which a separator and a cathode electrode are sequentially stacked on an air electrode portion arranged to allow contact with air flowing in through an air hole formed on the bottom of the case,
At least one gas discharge hole is formed on the upper surface of the case opposite the cathode electrode portion and is in communication with the outside,
A gas-release type zinc-air battery, characterized in that it is provided with a valve installed on the upper surface of the case to open the gas release hole when the set reference gas pressure exceeds the set standard gas pressure. The method of claim 1, wherein the valve
a first sheet joined to the upper surface of the case and having an opening and closing hole communicating with the gas discharge hole;
The opening and closing hole is covered on the upper surface of the first sheet, and when the gas pressure applied through the opening and closing hole is higher than the set standard gas pressure, the first passage is opened, and when it is lower than the reference gas pressure, the first passage is connected to the first sheet. A gas-emission type zinc-air battery comprising a second opening and closing sheet joined to the first sheet around the first passage to close the opening and closing hole in close contact. The gas-emission type zinc-air battery according to claim 2, wherein the first sheet and the second opening/closing sheet are made of a synthetic resin material, and each has a thickness of 0.01 to 1 mm. The method of claim 1, wherein the first and second electrodes are formed on the upper and lower surfaces of the case to be exposed to the outside, and when the out-gassing type zinc-air battery and the air hole are arranged to face each other, an air inflow space is created. Among the first and second regions that divide the bottom of the case into two to enable mutual connection while forming, a plurality of first coupling pipes with pin insertion grooves are formed in the first region, and in the second region, the A gas-release type zinc-air battery, characterized in that a plurality of fitting pins are inserted and fitted into the pin insertion groove, and the first electrode is formed in the center of the area corresponding to the second area. The method of claim 1, wherein the second electrode is formed at the center of the first area corresponding to the position of the first electrode when the second area is rotated 180 degrees,
The above case is
A first plate-shaped portion forming an upper surface on which the gas discharge hole is formed, a first vertical jaw portion extending downward from an edge of the first plate-shaped portion, and a first vertical jaw portion at a lower end of the first vertical jaw portion. an upper case having a second vertical jaw portion extending vertically downward so as to further expand the inner diameter;
A second plate-shaped portion forming a bottom surface in which a plurality of air holes are spaced apart from each other extends upward from the edge of the second plate-shaped portion so as to be coupled within the upper case, and enters the inside of the second vertical jaw portion. a lower case having a third vertical jaw portion extending to interfere with the first vertical jaw portion and having insertion holes formed in the third vertical jaw portion to be spaced apart from each other;
The sheet plate-shaped element that is tightly coupled to the inside of the lower case and forms the air electrode unit is formed in a rectangular frame shape so as to fit closely along the inner edge of the lower case, and the third is attached to the outer surface opposite to the inner side of the lower case. A gas-emission type zinc-air battery comprising a gasket having a protruding hook that is fitted into an insertion hole formed in a vertical jaw portion.

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