阅读说明：本技术 一种新型被动式微型金属空气电池 (Novel passive miniature metal-air battery ) 是由 朱恂 张浩然 叶丁丁 陈蓉 廖强 李俊 付乾 张亮 于 2019-10-01 设计创作，主要内容包括：本发明公开了一种新型被动式微型金属空气电池,包括阴极盖板、空气自呼吸阴极、滤纸隔膜、金属阳极和阳极盖板；其特征在于：所述阴极盖板上设置有滴水孔和自呼吸空气阴极窗口,所述空气自呼吸阴极设置在自呼吸空气阴极窗口的下方,所述金属阳极设置在空气自呼吸阴极的下方,滤纸隔膜设置在空气自呼吸阴极和金属阳极之间,且一端延伸到滴水孔的下方；所述滤纸隔膜上浸渍有氢氧化钾；所述阳极盖板设置在金属阳极的下方；本电池利用滤纸的吸水性实现电解液的被动输运,并由浸渍了氢氧化钾的滤纸遇水形成电解液导通阴阳极而启动,使用时只需滴加纯净水即可开始运行；本发明可广泛应用在能源、等领域。(The invention discloses a novel passive miniature metal-air battery, which comprises a cathode cover plate, an air self-breathing cathode, a filter paper diaphragm, a metal anode and an anode cover plate, wherein the cathode cover plate is arranged on the cathode; the method is characterized in that: the cathode cover plate is provided with a drip hole and a self-breathing air cathode window, the air self-breathing cathode is arranged below the self-breathing air cathode window, the metal anode is arranged below the air self-breathing cathode, the filter paper diaphragm is arranged between the air self-breathing cathode and the metal anode, and one end of the filter paper diaphragm extends to the lower part of the drip hole; potassium hydroxide is soaked on the filter paper diaphragm; the anode cover plate is arranged below the metal anode; the battery utilizes the water absorption of the filter paper to realize the passive transportation of the electrolyte, the filter paper soaked with the potassium hydroxide forms the electrolyte when meeting water to conduct the cathode and the anode and is started, and the battery can start to operate only by dropping purified water when in use; the invention can be widely applied to the fields of energy sources and the like.)

1. A novel passive miniature metal-air battery comprises a cathode cover plate (1), an air self-breathing cathode (4), a filter paper diaphragm (5), a metal anode (6) and an anode cover plate (7); the method is characterized in that: the cathode cover plate (1) is provided with a drip hole (2) and a self-breathing air cathode window (3), the air self-breathing cathode (4) is arranged below the self-breathing air cathode window (3), the metal anode (6) is arranged below the air self-breathing cathode (4), the filter paper diaphragm (5) is arranged between the air self-breathing cathode (4) and the metal anode (6), and one end of the filter paper diaphragm extends to the lower part of the drip hole (2); potassium hydroxide is soaked on the filter paper diaphragm (5); the anode cover plate (7) is arranged below the metal anode (6).

2. The novel passive miniature metal-air battery of claim 1, wherein: the air self-breathing cathode (4) is composed of hydrophobic carbon paper with a leveling layer and a catalytic layer.

Technical Field

The invention relates to the field of metal-air batteries, in particular to a novel passive miniature metal-air battery.

Background

The microfluidic chip has the advantages of high speed, low material consumption and less pollution when being applied to biochemical analysis, and shows good application prospect. Among them, micro point-of-care devices (POCs) based on electrochemical or electrical principles have been the leading direction of research and development. To drive such micro devices, the commonly used micro power supplies can be divided into three categories: the first type is that the disposable battery (such as an alkaline zinc-manganese dry battery) has the defects of high cost, large volume, resource waste, environmental pollution and the like; the second type is a rechargeable battery (such as a rechargeable lithium battery), which can be recycled for many times, but has the disadvantages of long charging time, unfriendly electrolyte to the environment, easy spontaneous combustion, etc. The third category is micro fuel cells (e.g., micro direct methanol fuel cells), however, the technology is still not mature and the cost is high. Therefore, the development of a miniaturized, low-cost, long-term storage and environment-friendly micro battery has important scientific and application values.

The main problems of the current metal-air battery are as follows:

(1) the air self-breathing cathode needs to be in direct contact with the external environment atmosphere, so that the problem of possible electrolyte leakage during daily storage is solved.

(2) Because the self-breathing cathode is exposed in the air, the electrolyte potassium hydroxide solution is contacted with carbon dioxide to react and is changed into potassium carbonate to deteriorate, so that the internal resistance is improved.

(3) The active metal simple substance can generate side reaction with water, thereby consuming anode materials and reducing the capacity of the battery.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a novel passive miniature metal-air battery.

The technical scheme of the invention is as follows: a novel passive miniature metal-air battery comprises a cathode cover plate, an air self-breathing cathode, a filter paper diaphragm, a metal anode and an anode cover plate; the method is characterized in that: the cathode cover plate is provided with a drip hole and a self-breathing air cathode window, the air self-breathing cathode is arranged below the self-breathing air cathode window, the metal anode is arranged below the air self-breathing cathode, the filter paper diaphragm is arranged between the air self-breathing cathode and the metal anode, and one end of the filter paper diaphragm extends to the lower part of the drip hole; potassium hydroxide is soaked on the filter paper diaphragm; the anode cover plate is arranged below the metal anode.

The invention provides a passive paper-based micro metal-air battery, which aims to solve the problems of liquid leakage, electrolyte deterioration and self-reaction corrosion of anode metal simple substances during the storage of the traditional metal-air battery. The invention adopts hydrophilic filter paper as a diaphragm between the cathode and the anode of the battery, and the front section of the filter paper is soaked with potassium hydroxide powder in advance; the battery is preserved with dry form when not working, and the battery operation only need can dissolve the potassium hydroxide powder to filter paper anterior segment dropwise add the pure water and form the potassium hydroxide solution to establish ion channel between the negative and positive poles, realize normal operating. The novel battery configuration avoids the leakage problem existing in the storage of the traditional metal-air battery, and simultaneously avoids the problems of anode corrosion and battery performance reduction caused by the side reaction of active metal simple substances and water in the storage process.

According to the preferable scheme of the novel passive miniature metal-air battery, the air self-breathing cathode is composed of hydrophobic carbon paper with a leveling layer and a catalytic layer.

The novel passive miniature metal-air battery has the beneficial effects that: the invention soaks the potassium hydroxide in the filter paper, and the potassium hydroxide is preserved in a dry form, thereby avoiding the problems of liquid electrolyte leakage, electrolyte deterioration and metal electrode self-corrosion caused by the exposure of the self-breathing cathode in the traditional metal-air battery to the environment.

1) The battery utilizes the water absorption of the filter paper to realize the passive transportation of the electrolyte, the filter paper soaked with the potassium hydroxide meets water to form the electrolyte to conduct the cathode and the anode and start, the operation can be started only by dripping purified water during use, liquid such as saliva and urine can be used under special conditions, and the raw materials can be obtained everywhere in daily life.

2) Air is used as an oxidant, other oxidants are not needed, the structure is simplified, and the operation cost of the battery is effectively reduced.

3) The reaction product of the battery is solid metal oxide, has no pollution to the environment and can be recycled.

4) Therefore, the battery can be used as a traditional power supply to provide electric energy, and can also be connected with an alarm (a lamp, a loudspeaker and the like) to detect whether water leakage and other conditions exist in the environment at any time.

The invention can be widely applied to the fields of energy, environmental protection and the like.

Drawings

Fig. 1 is a three-dimensional cross-sectional view of a novel passive miniature metal-air battery according to the present invention. The structure is schematic.

Fig. 2 is a front view of a novel passive miniature metal-air battery according to the present invention.

Fig. 3 is a top view of a novel passive miniature metal-air battery according to the present invention.

Fig. 4 is a left side view of a novel passive miniature metal-air battery of the present invention.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the accompanying drawings and specific embodiments. However, it should be noted that the present invention is not limited to the following embodiments.

Referring to fig. 1 to 4, a novel passive miniature metal-air battery comprises a cathode cover plate 1, an air self-breathing cathode 4, a filter paper diaphragm 5, a metal anode 6 and an anode cover plate 7 which are arranged in sequence from top to bottom; the air self-breathing cathode 4 is composed of hydrophobic carbon paper with a leveling layer and a catalytic layer. The air self-breathing cathode 4 is formed by spraying a catalyst such as platinum on the surface of hydrophobic carbon paper having a leveling layer by a spraying method, and is fixed under the cathode cover plate and is communicated with the external atmosphere through the self-breathing air cathode window 3. The cathode cover plate and the anode cover plate are both made of materials which are resistant to acid and alkali corrosion and have certain mechanical strength, such as PMMA plates. The metal anode 6 consists of titanium foil and a metal simple substance; specifically, a simple zinc metal such as zinc flakes, zinc powder, zinc foam, or the like can be used. The cathode cover plate 1 is provided with a drip hole 2 and a self-breathing air cathode window 3, the air self-breathing cathode 4 is arranged below the self-breathing air cathode window 3, the metal anode 6 is arranged below the air self-breathing cathode 4, the filter paper is arranged between the air self-breathing cathode 4 and the metal anode 6, and one end of the filter paper extends to the lower part of the drip hole 2; the filter paper diaphragm 5 is soaked with potassium hydroxide, and when the filter paper diaphragm is implemented, the filter paper can be placed in a potassium hydroxide solution with mass concentration to be soaked for two minutes and then placed in an oven to be dried, and then the filter paper diaphragm is clamped between a metal anode and an air self-breathing cathode; the anode cover plate 7 is arranged below the metal anode 6.

The anode reactant of the battery adopts a metal simple substance, wherein active metals such as zinc, aluminum, magnesium and the like are common), the cathode reactant is air, and the common electrolyte is potassium hydroxide solution. The battery electrode material has rich sources, is renewable and environment-friendly, and is suitable for constructing a micro power supply with simple structure and low manufacturing cost. The metal-air battery also has the advantages of high energy density, high output capacity, high discharge power and stable and safe discharge performance, thereby being suitable for a high-performance micro power supply.

The electrode reaction of the metal-air battery of the alkaline electrolyte takes zinc as the following:

anode:

Zn→Zn²⁺+2e^-

Zn²⁺+4OH^﹣→Zn(OH)₄ ^2-(E⁰＝-1.25V vs.NHE)

Zn(OH)₄ ^2-→ZnO+H₂O+2OH^﹣

possible side reactions at the anode:

Zn+2H₂O→Zn(OH)₂+H₂↑

cathode:

O₂+4H₂O+4e^﹣→4OH^﹣(E⁰＝0.4V vs.NHE)

and (3) total reaction:

2Zn+O₂→2ZnO(△E＝1.65V)

when the battery works, the anode zinc simple substance is oxidized to release electrons and change into zinc ions, one zinc ion is firstly complexed with four hydroxide radicals to form a complex compound zinc ion with four hydroxide radicals, and then the complex compound zinc ion is decomposed into zinc oxide, water and two hydroxide ions. The electrons travel along an external circuit to the cathode. Oxygen on the cathode side is firstly dispersed to the catalyst layer through the gas diffusion layer, and is combined with water and electrons introduced through an external circuit on a three-phase interface to generate hydroxide ions.

The anode material of the metal-air battery is a metal simple substance, and the common form is metal sheet, metal bar, metal powder and the like. The metal powder has large specific surface area and can increase reaction contact sites, so the electrochemical performance is better than that of a metal sheet and a metal rod. However, the metal powder electrode has a disadvantage in that the metal powder comes off the anode and contacts the cathode to cause a decrease in battery capacity, and thus a separator is required to be interposed between the cathode and the anode to separate the cathode and the anode. Such membranes need to have a suitable porosity that does not allow metal powder to pass through and also needs to have good ionic conductivity so that hydroxide transfer is not restricted. On the anode side, active metal can directly react with acid, the metal-air battery adopts potassium hydroxide solution as electrolyte, and the ion conductivity is highest and the battery performance is highest under the condition that the concentration of potassium hydroxide is 6 mol/L.

When the filter paper membrane is operated, water drops into the water dropping holes 2 formed in the cathode cover plate 1, the filter paper membrane 5 soaked with the potassium hydroxide is wetted by the water through the water dropping holes 2, the potassium hydroxide is dissolved in the water to form an electrolyte solution, and the cathode and the anode of the battery are conducted to start the battery. The filter paper diaphragm 5 can play a role in water locking because of hydrophilicity, and further reduces the possibility of liquid leakage. Oxygen in the air is transmitted to the catalyst layer through the cathode porous electrode, and combined with water molecules and electrons to generate reduction reaction to generate hydroxyl, and the hydroxyl is transmitted to the metal anode 6 through the filter paper membrane by the electrolyte in an electromigration mode. The metal anode 6 contacts with hydroxyl to react and release electrons, and the electrons reach the cathode through a load from an external circuit so as to form a battery loop, thereby ensuring that the battery can stably and continuously output electricity. In addition, the surface of the anode disassembled after operation can be recycled by zinc oxide, and the environment is not affected.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.