Soft package zinc-air battery with single-layer shell

Abstract

The invention provides a soft package zinc-air battery with a single-layer shell. The soft package zinc-air battery with the single-layer shell comprises an air positive electrode, a diaphragm, a negative electrode current collector and the shell which are sequentially stacked from top to bottom, the air positive electrode comprises a first gas-permeable membrane, a positive electrode current collector, a second gas-permeable membrane and a catalytic membrane which are sequentially stacked from top to bottom, and the overall size of the air positive electrode is larger than the size of the diaphragm, so that the electrolyte is prevented from permeating outwards from the diaphragm; the edge of the shell is fixedly connected with the edge of the catalytic membrane, and a closed zinc paste accommodating cavity is formed between the shell and the diaphragm; and tab glue is arranged between the tab of the negative current collector and the air positive electrode. According to the soft package zinc-air battery with the single-layer shell, the air positive electrode has no special size limitation, the positive electrode current collector can be directly overlapped with the breathable film and the catalytic film and then integrally cut, the soft package zinc-air battery is adaptive to coiled material automatic production equipment, the material cost of the shell is also reduced, and the energy consumption and the production period of the equipment are reduced.

Description

Technical Field

[0001] This invention relates to the field of zinc-air battery technology, and more particularly to a soft-pack zinc-air battery with a single-layer casing. Background Technology

[0002] Zinc-air batteries use metallic zinc as the negative electrode and oxygen from the air as the positive electrode. They have advantages such as high energy density, low cost, and environmental friendliness, making them an important new type of battery besides lithium-ion batteries. Among them, pouch zinc-air batteries, which use soft materials such as plastic film as the casing, have the characteristics of good sealing performance and light weight, and have become an important development direction for zinc-air batteries.

[0003] However, existing pouch zinc-air batteries have key problems in production and structural design: to avoid short circuits caused by contact between the positive electrode current collector (such as copper mesh) and the electrolyte, existing technologies require the current collector to be designed to be smaller than the breathable membrane and to be hidden in a specific location. This means that the positive electrode current collector cannot be automatically laminated into a roll with the breathable membrane and catalyst membrane and then cut. It can only be processed by manual positioning, resulting in extremely low production efficiency. At the same time, the shell of existing pouch zinc-air batteries needs to completely wrap the positive electrode, separator and other components. This requires not only multiple layers of shell material, but also multiple hot pressing processes to fix the components. The process is complex and costly, which seriously restricts the large-scale production and application of pouch zinc-air batteries.

[0004] Therefore, it is necessary to provide a single-layer shell soft-pack zinc-air battery to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a single-layer shell soft-pack zinc-air battery, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides a single-layer shell soft-pack zinc-air battery, comprising: an air positive electrode, a separator, a negative electrode current collector, zinc paste, and a shell, characterized in that: the air positive electrode, the separator, the negative electrode current collector, and the shell are stacked sequentially, the overall size of the air positive electrode is larger than the size of the separator, the edge of the shell is fixedly connected to the edge of the catalytic membrane and the separator, a closed zinc paste receiving cavity is formed between the shell and the separator, and tab adhesive is provided between the tab of the negative electrode current collector and the air positive electrode; Preferably, the air positive electrode and the outer side of the casing are provided with a first hot-pressing position and a second hot-pressing position. The first hot-pressing position is used to pre-fix the internal components of the zinc-air battery, and the second hot-pressing position is used for the final sealing of the single-layer casing soft-pack zinc-air battery.

[0007] Preferably, the air positive electrode is made by stacking a first breathable membrane, a positive electrode current collector, a second breathable membrane, and a catalytic membrane in sequence and then hot-pressing them together, and then cutting them according to a preset size, and the positive electrode current collector has tabs after cutting.

[0008] Preferably, the positive electrode current collector is any one of copper mesh, stainless steel mesh, nickel mesh or tin-plated copper mesh, and the size of the positive electrode current collector body is consistent with the size of the first breathable membrane, the second breathable membrane and the catalyst membrane.

[0009] Preferably, both the first and second breathable membranes are PTFE waterproof and breathable membranes, and the catalyst membrane is a carbon-based catalyst membrane.

[0010] Preferably, the shell is a plastic film, which is any one of polycarbonate film, nylon film or aluminum film.

[0011] Preferably, the diaphragm is any one of an alkaline diaphragm, a polypropylene diaphragm, or a glass fiber diaphragm.

[0012] Preferably, the negative electrode current collector is any one of copper mesh, tin-plated copper mesh, stainless steel, copper foil, tin-plated copper foil, or tin foil.

[0013] Preferably, the tab adhesive is a special adhesive for tabs or a hot melt adhesive.

[0014] Preferably, zinc paste is filled in a cavity formed by the shell, diaphragm and negative electrode current collector. The zinc paste is made by mixing zinc powder, dispersant and potassium hydroxide solution.

[0015] Compared with related technologies, the single-layer shell soft-pack zinc-air battery provided by the present invention has the following beneficial effects: First, it eliminates special size restrictions for the air positive electrode, allowing the positive electrode current collector to be directly stacked with the breathable membrane and catalytic membrane and then cut as a whole, making it compatible with automated roll material production equipment, reducing manual intervention, and significantly improving the continuity and efficiency of positive electrode production.

[0016] Second, by using the air positive electrode as the upper shell, the use of one shell material is reduced. At the same time, the zinc-air battery can be manufactured by only two hot pressing operations (the internal structure of the zinc-air battery is pre-fixed during the first hot pressing operation, and the entire structure is sealed during the second hot pressing operation). This replaces the existing multiple hot pressing process, which not only reduces the material cost of the shell, but also reduces equipment energy consumption and production cycle, further controlling the overall production cost. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a bottom view of the diaphragm and above structure of the present invention; Figure 3 This is a schematic diagram of the structure of the air positive electrode of the present invention.

[0018] The following labels are used in the diagram: 10, positive air electrode; 11, first permeable membrane; 12, positive electrode current collector; 13, second permeable membrane; 14, catalytic membrane; 20, separator; 30, negative electrode current collector; 31, tab adhesive; 40, shell; 51, first hot-pressing position; 52, second hot-pressing position. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Please refer to the following: Figures 1 to 3 A single-layer soft-pack zinc-air battery includes: an air positive electrode 10, a separator 20, a negative electrode current collector 30, and a casing 40. The air positive electrode 10, separator 20, negative electrode current collector 30, and casing 40 are stacked sequentially from top to bottom. The air positive electrode 10 can introduce oxygen from the air and prevent electrolyte from entering its interior. The separator 20 is used to separate the positive and negative electrodes and allows electrolyte ions to pass through. The negative electrode current collector 30 is used to collect negative electrode current. The casing 40 has a certain strength and can cooperate with the air positive electrode 10 to form a sealed cavity inside the zinc-air battery.

[0021] The air positive electrode 10 has a layered composite structure, which includes, from top to bottom: a first breathable membrane 11, a positive electrode current collector 12, a second breathable membrane 13, and a catalytic membrane 14. The overall size of the air positive electrode 10 is larger than that of the separator 20, that is, the edge of the air positive electrode 10 protrudes beyond the edge of the separator 20, ensuring that it can completely cover the separator 20 when it is subsequently combined with the shell 40, thus isolating the contact path between the electrolyte and the positive electrode current collector 12.

[0022] The diaphragm 20 is disposed between the positive air electrode 10 and the negative current collector 30 to separate the positive air electrode 10 and the negative current collector 30, prevent short circuit, and allow electrolyte ions to pass through. Since the size of the positive air electrode 10 is larger than that of the diaphragm 20, the diaphragm 20 can be limited by the positive air electrode 10 and the housing 40 without additional fixation.

[0023] The negative electrode current collector 30 is located on the side of the diaphragm 20 away from the positive air electrode 10. The side of its tab facing the positive air electrode 10 is coated with tab adhesive 31. The tab adhesive 31 is a special adhesive for tabs or hot melt adhesive, which can prevent the negative electrode tab from directly contacting the positive air electrode 10 and causing a short circuit.

[0024] The housing 40 is made of a plastic film (such as a polycarbonate film or a nylon film), and the air positive electrode 10 is used as the upper housing. The plastic film is tightly bonded to the catalytic film 14 of the air positive electrode 10, and the separator 20 is located between the plastic film and the catalytic film 14 and bonded synchronously. The size of the plastic film is the same as that of the catalytic film 14 to ensure the integrity of the seal. The plastic film is provided with a first hot-pressing position 51 and a second hot-pressing position 52.

[0025] The first breathable membrane 11, the positive electrode current collector 12, the second breathable membrane 13, and the catalyst membrane 14 are stacked in a top-to-bottom order and bonded together by hot pressing (temperature 120-150℃, pressure 0.3-0.5MPa) or hydraulic pressing (pressure 0.5-0.8MPa). After bonding, the membrane is cut to a preset size. During cutting, tabs are reserved on the positive electrode current collector 12. There is no need to impose special restrictions on the size of the positive electrode current collector 12 (it can be consistent with the size of the breathable membrane and the catalyst membrane 14), thus realizing automated composite cutting of the roll material.

[0026] Stack the air positive electrode 10, separator 20, and negative current collector 30 in that order (with separator 20 in close contact with the first breathable membrane 11 of the air positive electrode 10). Cover the negative current collector 30 with a plastic film on the side away from separator 20, ensuring that the edge of the plastic film is aligned with the edge of the catalyst membrane 14. Perform hot pressing at the first hot pressing position 51 (temperature 130-160℃, pressure 0.4-0.6MPa, time 3-5s), leaving only the right edge of the plastic film and catalyst membrane 14 unfixed, forming a pre-fabricated cell bag as a channel for subsequent zinc paste injection.

[0027] Zinc powder, dispersant (such as sodium carboxymethyl cellulose), and potassium hydroxide solution are mixed and stirred evenly in a certain proportion to make zinc paste with suitable fluidity. Then, the unfixed edge of the plastic film and the catalyst film 14 is opened, and the zinc paste is injected into the cavity formed by the shell 40, the diaphragm 20, and the negative electrode current collector 30. Finally, hot pressing is performed at the second hot pressing position 52 (temperature 140-170℃, pressure 0.5-0.7MPa, time 4-6s) to complete the cell manufacturing. The entire preparation process only requires two hot pressings, which greatly simplifies the process.

[0028] The working principle of the single-layer shell soft-pack zinc-air battery provided by this invention is as follows: This battery operates based on the electrochemical reaction principle of zinc and air, and outputs electrical energy through electron transfer and ion migration between the positive and negative electrodes. At the same time, its unique single-layer shell and layered structure design ensures that the reaction is efficient and stable. The air positive electrode 10 serves as the oxygen receiving end of the reaction. Its layered structure (first permeable membrane 11, positive electrode current collector 12, second permeable membrane 13, and catalytic membrane 14) allows air to pass through while preventing electrolyte leakage. The catalytic membrane 14 (carbon-based material) provides active sites for the oxygen reduction reaction, while the positive electrode current collector 12 (copper mesh, stainless steel mesh, etc.) is responsible for collecting electrons generated by the positive electrode and conducting them to the external circuit. It consists of a negative electrode current collector 30 (copper foil, tin-plated copper foil, etc.) and zinc paste (made of zinc powder, dispersant and potassium hydroxide solution). The zinc paste, as an active material, is the source of electron supply. The negative electrode current collector 30 conducts the electrons generated by zinc oxidation to the external circuit. The electrolyte (potassium hydroxide solution, contained in the zinc paste) provides a channel for ion migration. The diaphragm 20 (alkaline diaphragm, polypropylene diaphragm, etc.) separates the positive and negative electrodes to prevent short circuits, but allows hydroxide ions to pass through, ensuring the smooth flow of the ion circuit. The plastic film (shell 40) and the catalyst film 14 work together to form a sealed zinc paste containment cavity, which can prevent electrolyte leakage. The first venting membrane 11 and the second venting membrane 13 can ensure that oxygen can continuously enter the positive electrode area.

[0029] The overall size of the air positive electrode 10 is larger than that of the diaphragm 20. Together with the shell 40, it forms a closed zinc paste containment cavity, which only allows the electrolyte to be confined to the area between the negative electrode and the diaphragm 20, avoiding contact between the electrolyte and the positive electrode current collector 12, preventing short circuits caused by direct conduction between the positive and negative electrodes, and ensuring that electrons are conducted only through the external circuit. The first breathable membrane 11 and the second breathable membrane 13 (PTFE material) have both breathability and waterproofness. They can allow oxygen to enter the catalyst membrane 14 to participate in the reaction, while preventing the electrolyte from leaking into the positive electrode current collector 12. The carbon-based material of the catalyst membrane 14 increases the oxygen reduction reaction rate, reduces the internal resistance of the reaction, and ensures the battery discharge efficiency. The tab adhesive 31 between the negative current collector 30 and the positive air electrode 10 prevents the negative current collector 30 and the positive current collector 12 from directly contacting and short-circuiting, ensuring a unique electron conduction path. The sealing design of the first and second hot-press positions 52 not only fixes the position of the internal components, but also prevents electrolyte leakage and abnormal air entry, maintaining a stable reaction environment.

[0030] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A single-layer shell soft-pack zinc-air battery, comprising: An air positive electrode (10), a separator (20), a negative electrode current collector (30), zinc paste, and a housing (40) are characterized in that: the air positive electrode (10), the separator (20), the negative electrode current collector (30), and the housing (40) are stacked in sequence, the overall size of the air positive electrode (10) is larger than the size of the separator (20), the edge of the housing (40) is fixedly connected to the edge of the catalyst membrane (14) and the edge of the separator (20), a closed zinc paste receiving cavity is formed between the housing (40) and the separator (20), and a tab adhesive (31) is provided between the tab of the negative electrode current collector (30) and the air positive electrode (10).

2. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The air positive electrode (10) and the outer side of the housing (40) are provided with a first hot-pressing position (51) and a second hot-pressing position (52). The first hot-pressing position (51) is used to pre-fix the internal components of the zinc-air battery, and the second hot-pressing position (52) is used for the final sealing of the soft-pack zinc-air battery with the single-layer housing.

3. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The air positive electrode (10) is made by stacking the first breathable membrane (11), the positive electrode current collector (12), the second breathable membrane (13), and the catalyst membrane (14) in sequence and then hot-pressing them together. It is then cut to the preset size, and the positive electrode current collector (12) has tabs after cutting.

4. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The positive electrode current collector (12) is any one of copper mesh, stainless steel mesh, nickel mesh or tin-plated copper mesh, and the size of the main body of the positive electrode current collector (12) is consistent with the size of the first breathable membrane (11), the second breathable membrane (13) and the catalyst membrane (14).

5. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The first breathable membrane (11) and the second breathable membrane (13) are both PTFE waterproof and breathable membranes, and the catalyst membrane (14) is a carbon-based catalyst membrane (14).

6. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The housing (40) is a plastic film, which is any one of polycarbonate film, nylon film or aluminum film.

7. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The diaphragm (20) is any one of an alkaline diaphragm, a polypropylene diaphragm, or a glass fiber diaphragm.

8. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The negative electrode current collector (30) is any one of copper mesh, tin-plated copper mesh, stainless steel, copper foil, tin-plated copper foil or tin foil.

9. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The tab adhesive (31) is a special adhesive or hot melt adhesive for tabs.

10. A single-layer shell soft-pack zinc-air battery according to claim 1, characterized in that, The zinc paste is filled in a cavity formed by the shell (40), the diaphragm (20) and the negative electrode current collector (30). The zinc paste is made by mixing zinc powder, dispersant and potassium hydroxide solution.

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