A positive electrode of a soft-pack zinc-air battery and a cell structure thereof

Abstract

The utility model discloses a kind of positive pole and its electric core structure of soft package zinc air battery, involve zinc air power bank technical field.The utility model includes first gas permeable membrane, positive pole current collector, second gas permeable membrane and catalytic membrane, the positive pole current collector is equipped with tab, second gas permeable membrane and positive pole current collector shape adaptation and present protruding, the protruding position of second gas permeable membrane is located below the tab of positive pole current collector, and tab width is less than the protruding position width of second gas permeable membrane, tab length is greater than the protruding position length of second gas permeable membrane.The utility model is designed as protruding by second gas permeable membrane and with positive pole current collector adaptation, make tab lead out from upper and lower shell, need not lead out from gas permeable hole, completely save the operation of twice bending of tab in prior art, adaptation mechanical automation production line's continuous processing demand.

Description

Technical Field

[0001] This utility model belongs to the technical field of zinc-air power bank, and specifically relates to the positive electrode and cell structure of a soft-pack zinc-air battery. Background Technology

[0002] A zinc-air battery power bank is a charging device that uses a zinc-air battery as its energy source. A zinc-air battery is a hybrid of a battery and a fuel cell, characterized by low cost, high energy output, and high safety. Its working principle involves using oxygen from the air as the positive electrode active material and metallic zinc as the negative electrode active material to generate electrical energy through an electrochemical reaction. Due to the high safety of zinc-air batteries, the use of flexible fabric as the casing offers significant advantages.

[0003] A positive electrode for a soft-pack zinc-air battery is disclosed in Chinese Patent Network CN218160455U, which includes a first waterproof and breathable membrane, a thermoplastic membrane, and a positive electrode current collector. The thermoplastic membrane has an installation hole, the first waterproof and breathable membrane seals one side of the installation hole, the main body of the positive electrode current collector is placed in the installation hole, and the tab of the positive electrode current collector extends out from the side of the thermoplastic membrane away from the first waterproof and breathable membrane.

[0004] Soft-pack zinc-air batteries made with plastic film casings have the advantages of excellent sealing performance, high energy density, and low price. However, if the copper current collector of the positive electrode of the zinc-air battery comes into contact with the electrolyte, it will cause a short circuit. As described in the aforementioned patent, the copper mesh is hidden in the vent membrane to prevent it from coming into contact with the electrolyte. This means that the tab of the positive electrode current collector needs to be led out from the vent hole. However, leading the tab out from the vent hole brings many problems. First, the tab part needs to be bent twice, that is, bent from an L-shape through the vent hole and then bent back to an L-shape. This is very inconvenient in mechanical automated manufacturing. Second, leading the tab out from the vent hole results in very low structural strength, which can easily cause the positive electrode to tear under stress.

[0005] If the positive electrode tab is simply passed through the positive and negative electrode shells, it is easy for the electrolyte to come into contact with the copper, causing a short circuit problem due to the formation of copper dendrites; or the zinc paste may come into direct contact with the positive electrode, causing a short circuit.

[0006] There are currently no effective solutions to the problems in the relevant technologies. Utility Model Content

[0007] To solve the above-mentioned technical problems, this utility model provides a positive electrode and cell structure for a soft-pack zinc-air battery, including a first gas-permeable membrane, a positive electrode current collector, a second gas-permeable membrane, and a catalytic membrane. The positive electrode current collector is provided with tabs. The second gas-permeable membrane is adapted to the shape of the positive electrode current collector and is protruding. The protruding position of the second gas-permeable membrane is located below the tabs of the positive electrode current collector, and the width of the tabs is smaller than the width of the protruding position of the second gas-permeable membrane, while the length of the tabs is greater than the length of the protruding position of the second gas-permeable membrane.

[0008] The first permeable membrane, the positive electrode current collector, the second permeable membrane, and the catalytic membrane are combined into an integrated structure by hot pressing or hydraulic pressing.

[0009] The size of the first breathable membrane on the tab side is smaller than the size of the second breathable membrane on the tab side.

[0010] The positive electrode current collector is a conductive metal mesh, and the positive electrode current collector has an L-shaped structure.

[0011] The overall size of the positive current collector is slightly smaller than the overall size of the second permeable membrane.

[0012] The protruding part of the second breathable membrane extends to the edge of the second breathable membrane, forming an integrated protruding structure.

[0013] The device includes an air positive electrode, an upper shell, a lower shell, and a diaphragm. The air positive electrode includes a first permeable membrane, a positive electrode current collector, a second permeable membrane, and a catalytic membrane. The positive electrode current collector has tabs. The second permeable membrane is shaped to fit the positive electrode current collector and protrudes. The protruding part of the second permeable membrane is located below the tabs of the positive electrode current collector, and the width of the tabs is smaller than the width of the protruding part of the second permeable membrane, while the length of the tabs is greater than the length of the protruding part of the second permeable membrane. The upper shell is fixed to the edge of the air positive electrode and the diaphragm, and the lower shell is fixed to the edge of the upper shell. The area of ​​the diaphragm is larger than the horizontal projected area of ​​the air positive electrode. The tabs of the positive electrode current collector pass through the space between the upper shell and the lower shell. The upper shell is fixed to the protruding part of the second permeable membrane and the tabs of the positive electrode current collector, while the lower shell is fixed to the protruding part of the second permeable membrane and the edge of the diaphragm.

[0014] The upper shell is made of plastic film, and the air positive electrode is heat-pressed to the upper shell and the diaphragm on both sides respectively.

[0015] The upper shell, air positive electrode, diaphragm, and lower shell are hot-pressed together to form a pre-fabricated cell bag. The pre-fabricated cell bag has a side away from the electrode tab that is not hot-pressed, which serves as an injection channel for the zinc negative electrode.

[0016] This utility model has the following beneficial effects: This invention designs the second breathable membrane as a protrusion that is compatible with the positive electrode current collector, and heat-presses the lower shell, the edge of the diaphragm, and the protruding part of the second breathable membrane together, thus preventing the breathable membrane from contacting the zinc paste and preventing short circuits. It also avoids the problem of short circuits caused by the branched copper penetrating the diaphragm due to contact between the positive electrode tab and the electrolyte. As a result, the tab can be led out from between the upper and lower shells without having to be led out from the vent hole, completely eliminating the need for two bending operations of the tab in the prior art, and adapting to the continuous processing requirements of automated production lines.

[0017] Meanwhile, this invention forms a double support by hot-pressing the electrode tab lead-out position with the edge of the second breathable membrane and the upper and lower shells, thereby improving the connection strength between the electrode tab and the positive electrode and effectively solving the problem of low strength of the existing electrode tab structure.

[0018] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] Figure 1 This is a three-dimensional exploded structure diagram of the present invention; Figure 2 This is a top-view structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the air positive electrode structure of this utility model; Figure 4 This is a schematic diagram of the air positive electrode structure of this utility model from a top view. Figure 5 This is a schematic diagram of the second embodiment of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 10, upper shell; 20, positive air electrode; 21, first permeable membrane; 22, positive electrode current collector; 23, second permeable membrane; 24, catalytic membrane; 30, separator; 40, negative electrode current collector; 50, lower shell. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the following will be described in conjunction with the accompanying drawings of the embodiments of this utility model. Figure 1-5 The technical solutions of the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model are within the protection scope of this utility model.

[0022] Please see Figures 1-4 As shown: This embodiment provides a positive electrode structure for a soft-pack zinc-air battery, including a first permeable membrane 21, a positive electrode current collector 22, a second permeable membrane 23, and a catalyst membrane 24 stacked sequentially. The positive electrode current collector 22 is provided with tabs. The second permeable membrane 23 is adapted to the shape of the positive electrode current collector 22 and is protruding. The protruding position of the second permeable membrane 23 is located below the tabs of the positive electrode current collector 22, and the width of the tabs is smaller than the width of the protruding position of the second permeable membrane 23, while the length of the tabs is greater than the length of the protruding position of the second permeable membrane 23.

[0023] The first permeable membrane 21, the positive electrode current collector 22, the second permeable membrane 23, and the catalyst membrane 24 are integrated into a single structure by hot pressing or hydraulic bonding. The bonding method needs to be selected according to the actual situation.

[0024] The size of the first breathable membrane 21 on the tab side is smaller than the size of the second breathable membrane 23 on the tab side. The size of the diaphragm 30 on the tab side is adapted to the size of the second breathable membrane 23 on the tab side, so as to avoid the tab of the positive current collector 22.

[0025] The positive current collector 22 is a conductive metal mesh, and the positive current collector 22 has an L-shaped structure. The overall size of the positive current collector 22 is slightly smaller than the overall size of the second breathable membrane 23, so as to ensure that the positive current collector 22 is completely covered by the second breathable membrane 23 and avoids direct contact with the diaphragm 30.

[0026] This embodiment also provides a soft-pack zinc-air battery cell structure, including an air positive electrode 20, an upper shell 10, a lower shell 50, and a separator 30. The air positive electrode 20 includes a first permeable membrane 21, a positive current collector 22, a second permeable membrane 23, and a catalyst membrane 24 stacked sequentially. The positive current collector 22 is provided with tabs. The second permeable membrane 23 is adapted to the shape of the positive current collector 22 and is protruding. The protruding position of the second permeable membrane 23 is located below the tab of the positive current collector 22, and the width of the tab is smaller than the width of the protruding position of the second permeable membrane 23, and the length of the tab is greater than the length of the protruding position of the second permeable membrane 23. The upper shell 10 is fixed to the edge of the positive air electrode 20 and the diaphragm 30, and the lower shell 50 is fixed to the edge of the upper shell 10. The area of ​​the diaphragm 30 is larger than the horizontal projected area of ​​the positive air electrode 20. The tab of the positive current collector 22 passes through the space between the upper shell 10 and the lower shell 50. The upper shell 10 is fixed to the protruding position of the second breathable membrane 23 and the tab of the positive current collector 22. The lower shell 50 is fixed to the protruding position of the second breathable membrane 23 and the edge of the diaphragm 30. When the upper shell 10 is hot-pressed, the diaphragm 30 will be fixed together on all sides, and the diaphragm 30 at the protruding position of the second breathable membrane 23 will be in an unfixed state. When the lower shell 50 is hot-pressed, the lower shell 50 will be hot-pressed together with the diaphragm 30 at the protruding position and the protruding position of the second breathable membrane 23.

[0027] The upper shell 10 is a plastic film. The air positive electrode 20 is hot-pressed to the upper shell 10 and the separator 30 on both sides respectively. The other side of the separator 30 is hot-pressed to the lower shell 50. The upper shell 10 has a hollow area in the middle, which corresponds to the position of the positive electrode structure and is used for battery ventilation. The hollow area does not cover the separator 30 to avoid blocking gas flow.

[0028] The upper shell 10, the air positive electrode 20, the diaphragm 30, and the lower shell 50 are hot-pressed together to form a pre-fabricated cell bag. The pre-fabricated cell bag has a side away from the electrode tab that is not hot-pressed, which serves as an injection channel for the zinc negative electrode.

[0029] The cell structure also has a negative current collector 40, which is disposed between the lower housing 50 and the diaphragm 30. The diaphragm 30 completely isolates the negative current collector 40 from the positive air electrode 20. The negative current collector 40 is used to collect negative current.

[0030] The zinc negative electrode is a zinc sheet or a mixture of zinc powder and electrolyte. After the zinc negative electrode is injected into the negative electrode accommodating space of the prefabricated cell bag, it comes into close contact with the negative electrode current collector 40. The diaphragm 30 isolates the zinc negative electrode from the air positive electrode 20, and then the injection channel is sealed.

[0031] The working principle is as follows: Stack the layers in the following order: "first breathable membrane 21 → positive electrode current collector 22 → second breathable membrane 23 → catalyst membrane 24". Ensure that each layer is aligned and that the tabs of the positive electrode current collector 22 are positioned above the protruding position of the second breathable membrane 23. Perform a composite process on the stacked air positive electrode 20 to ensure that each layer is tightly bonded and forms an integral air positive electrode 20. During the composite process, ensure that the protruding structure of the second breathable membrane 23 is not deformed and that the tabs are not shifted. The prepared air cathode 20 and separator 30 are stacked together, so that the separator 30 is attached to the side of the catalyst membrane 24 of the air cathode 20, and the clearance notch of the separator 30 is aligned with the position of the electrode tab. Then, the upper shell 10 is covered on the side of the air cathode 20 away from the separator 30, ensuring that the hollow area of ​​the upper shell 10 corresponds to the center of the air cathode 20. Then, the air cathode 20, separator 30 and upper shell 10 are hot-pressed together. The negative electrode current collector 40 is laid flat on the inside of the lower housing 50 to ensure that the negative electrode current collector 40 is tightly attached to the lower housing 50. Then, the air positive electrode 20 and the diaphragm 30, which have been composited, are flipped over with the upper housing 10 so that the side of the diaphragm 30 away from the air positive electrode 20 is aligned with the negative electrode current collector 40 of the lower housing 50. Hot pressing is performed again. During the hot pressing process, the edges of the second breathable membrane 23 and the edges of the diaphragm 30 need to be completely pressed between the upper housing 10 and the lower housing 50. At the same time, the side away from the electrode tab is left unpressed to form a zinc negative electrode injection channel, and finally the prefabricated cell bag is obtained. Zinc negative electrodes are injected into the negative electrode space of the pre-made cell bag through the injection channel. The injection amount is determined according to the battery capacity requirements. After injection, the injection channel is heat-sealed using a heat-sealing machine to complete the cell sealing and finally obtain a soft-pack zinc-air battery.

[0032] Example 2, as Figure 5 As shown: The protruding part of the second breathable membrane 23 extends to the edge of the second breathable membrane 23 to form an integrated protruding structure. The avoidance structure of the diaphragm 30 is adapted to the integrated protruding structure, thereby reducing the cutting process of the breathable membrane.

[0033] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A positive electrode structure for a soft-pack zinc-air battery, comprising a first permeable membrane (21), a positive electrode current collector (22), a second permeable membrane (23), and a catalyst membrane (24), characterized in that: The positive current collector (22) is provided with tabs. The second breathable membrane (23) is adapted to the shape of the positive current collector (22) and is protruding. The protruding position of the second breathable membrane (23) is located below the tab of the positive current collector (22), and the width of the tab is smaller than the width of the protruding position of the second breathable membrane (23), and the length of the tab is greater than the length of the protruding position of the second breathable membrane (23).

2. The positive electrode structure of a soft-pack zinc-air battery according to claim 1, characterized in that, The first breathable membrane (21), the positive electrode current collector (22), the second breathable membrane (23), and the catalyst membrane (24) are integrated into a single structure by hot pressing or hydraulic bonding.

3. The positive electrode structure of a soft-pack zinc-air battery according to claim 1, characterized in that, The size of the first breathable membrane (21) on the tab side is smaller than the size of the second breathable membrane (23) on the tab side.

4. The positive electrode structure of a soft-pack zinc-air battery according to claim 1, characterized in that, The positive current collector (22) is a conductive metal mesh, and the positive current collector (22) has an L-shaped structure.

5. The positive electrode structure of a soft-pack zinc-air battery according to claim 1, characterized in that, The overall size of the positive current collector (22) is slightly smaller than the overall size of the second breathable membrane (23).

6. The positive electrode structure of a soft-pack zinc-air battery according to claim 1, characterized in that, The protruding part of the second breathable membrane (23) extends to the edge of the second breathable membrane (23) to form an integrated protruding structure.

7. A soft-pack zinc-air battery cell structure, comprising an air positive electrode (20), an upper shell (10), a lower shell (50), and a separator (30), wherein the air positive electrode (20) comprises a first permeable membrane (21), a positive current collector (22), a second permeable membrane (23), and a catalyst membrane (24), wherein the positive current collector (22) is provided with tabs, the second permeable membrane (23) is adapted to the shape of the positive current collector (22) and is protruding, the protruding position of the second permeable membrane (23) is located below the tab of the positive current collector (22), and the width of the tab is smaller than the width of the protruding position of the second permeable membrane (23), and the length of the tab is greater than the length of the protruding position of the second permeable membrane (23), the upper shell (10) is fixed to the edges of the air positive electrode (20) and the separator (30), the lower shell (50) is fixed to the edges of the upper shell (10), and the area of ​​the separator (30) is larger than the horizontal projected area of ​​the air positive electrode (20), characterized in that, The tab of the positive current collector (22) passes between the upper shell (10) and the lower shell (50). The upper shell (10) is fixed to the protruding position of the second breathable membrane (23) and the tab of the positive current collector (22). The lower shell (50) is fixed to the protruding position of the second breathable membrane (23) and the edge of the diaphragm (30).

8. The soft-pack zinc-air battery cell structure according to claim 7, characterized in that, The upper shell (10) is a plastic film, and the air positive electrode (20) is hot-pressed and bonded to the upper shell (10) and the diaphragm (30) on both sides respectively.

9. The soft-pack zinc-air battery cell structure according to claim 7, characterized in that, The upper shell (10), the air positive electrode (20), the diaphragm (30), and the lower shell (50) are hot-pressed together to form a pre-made cell bag. The pre-made cell bag has a side away from the tab that is not hot-pressed, which serves as an injection channel for the zinc negative electrode.

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