A structure of a soft package zinc air battery with diaphragm fixed on both sides

Abstract

The utility model provides a kind of diaphragm double-face fixed soft package zinc air battery structure.The diaphragm double-face fixed soft package zinc air battery structure includes: upper shell, for the soft shell with air permeable cavity;Air positive pole, set in the lower of upper shell, including: first air permeable membrane, positive pole current collector, second air permeable membrane and catalytic membrane, first air permeable membrane, positive pole current collector, second air permeable membrane and catalytic membrane are sequentially stacked from top to bottom, first air permeable membrane and second air permeable membrane can wrap positive pole current collector;Negative pole current collector and lower shell, sequentially set in the lower of diaphragm;The area between diaphragm and lower shell is used for injecting zinc negative pole.The diaphragm double-face fixed soft package zinc air battery structure provided by the utility model is fixed by double-face hot pressing of diaphragm four around and upper and lower shell edge, avoid the defect that diaphragm and shell are not firmly bonded due to positive pole current collector thickness in traditional single-side fixing, zinc paste and positive pole direct contact path are blocked from structure, avoid short circuit risk.

Description

Technical Field

[0001] This utility model relates to the field of soft-pack zinc-air battery technology, and in particular to a soft-pack zinc-air battery structure with a separator fixed on both sides. Background Technology

[0002] Zinc-air batteries, using metallic zinc as the negative electrode and oxygen from the air as the positive electrode, offer advantages such as high specific energy, low cost, and environmental friendliness, and have broad application prospects in portable electronic devices, energy storage, and other fields. Among them, pouch zinc-air batteries, employing soft casings such as plastic films, offer superior sealing performance, lighter weight, and higher energy density compared to traditional rigid-cased zinc-air batteries, making them a current research hotspot.

[0003] However, the existing design of the separator in soft-pack zinc-air batteries generally involves fixing it only to the positive electrode side or the upper shell. That is, the positive electrode, separator and upper shell are first hot-pressed together, and the lower shell is hot-pressed with the upper shell without the separator. Since the positive electrode has a certain thickness and the separator needs to protrude from the positive electrode to achieve isolation, the separator and upper shell are prone to poor adhesion during hot pressing. If the hot pressing temperature is increased or the hot pressing time is extended to improve the adhesion effect, the plastic shell will be damaged by heat. In the end, the zinc paste will still cause a short circuit due to direct contact with the positive electrode.

[0004] Therefore, it is necessary to provide a soft-pack zinc-air battery structure with a separator fixed on both sides to solve the above-mentioned technical problems. Utility Model Content

[0005] This invention provides a soft-pack zinc-air battery structure with a diaphragm fixed on both sides, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, this utility model provides a soft-pack zinc-air battery structure with a diaphragm fixed on both sides, comprising: an upper shell, which is a soft shell with a breathable cavity; An air positive electrode, located below the upper shell, includes: a first breathable membrane, a positive electrode current collector, a second breathable membrane, and a catalytic membrane. The first breathable membrane, the positive electrode current collector, the second breathable membrane, and the catalytic membrane are stacked sequentially from top to bottom. The first and second breathable membranes can wrap the positive electrode current collector to prevent the positive electrode current collector from directly contacting the electrolyte. A diaphragm is placed below the positive air electrode, with its edges protruding beyond the positive air electrode. The negative electrode current collector and the lower shell are sequentially arranged below the diaphragm, and the edge of the diaphragm is located between the hot-pressed edges of the upper shell and the lower shell; The diaphragm is fixed around its perimeter by hot pressing along the edges of the upper and lower shells to prevent displacement and to physically isolate the positive current collector from the negative current collector. The area between the diaphragm and the lower shell is used for injecting the zinc negative electrode.

[0007] Preferably, the size of the first breathable membrane on the positive electrode current collector tab side is smaller than the size of the second breathable membrane, the positive electrode current collector is L-shaped, and the size of the positive electrode current collector is slightly smaller than the size of the second breathable membrane.

[0008] The first breathable membrane and the second breathable membrane are respectively one of PTFE waterproof breathable membrane and polypropylene breathable membrane, and the thickness of the first breathable membrane is greater than the thickness of the second breathable membrane.

[0009] The positive electrode current collector is a nickel mesh, copper mesh, or stainless steel mesh, and the negative electrode current collector is a copper mesh, tin-plated copper mesh, or stainless iron.

[0010] The upper and lower shells are respectively provided with upper and lower hot-pressing positions on their edges. The diaphragm is clamped and fixed by the upper and lower shells through the hot-pressing action between the upper and lower hot-pressing positions.

[0011] Both the upper and lower shells are made of nylon, aluminum, or polyethylene composite film, and the width of the upper and lower hot-pressing positions is 3-5mm.

[0012] The zinc negative electrode is a mixture of zinc sheet or zinc powder and KOH electrolyte, wherein the zinc powder accounts for 60-80% of the mass of the mixture.

[0013] The catalyst membrane is attached to the side of the first breathable membrane away from the positive electrode current collector, and the edge of the catalyst membrane does not protrude beyond the edge of the first breathable membrane.

[0014] The diaphragm is an alkaline diaphragm, a polypropylene diaphragm, or a glass fiber diaphragm, and the diaphragm protrudes 2-5 mm from the periphery of the positive electrode current collector.

[0015] Compared with related technologies, the soft-pack zinc-air battery structure with a double-sided fixed diaphragm provided by this utility model has the following beneficial effects: First, by fixing the diaphragm with double-sided hot pressing around the perimeter and the edges of the upper and lower shells, the defect of poor adhesion between the diaphragm and the shell due to the thickness of the positive electrode current collector, which is a problem in traditional single-sided fixing, is avoided. This structurally blocks the direct contact path between the zinc paste and the positive electrode, thus avoiding the risk of short circuit.

[0016] Second, there is no need to increase the hot-pressing temperature or extend the time to enhance the bonding strength between the diaphragm and the shell. The structural design of double-sided hot-pressing edges can achieve a firm fixation and protect the plastic shell from high-temperature damage.

[0017] Third, the size matching of each layer of the air positive electrode (the first permeable membrane tab side is reduced, the L-shaped positive electrode current collector and the catalytic membrane does not protrude) not only continues the advantage of the traditional structure of "avoiding contact between the current collector and the electrolyte", but also further reduces the risk of short circuits caused by multiple components working together. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a top view of the structure of this utility model; Figure 3 This is a top view of the structure below the diaphragm of this utility model; Figure 4 This is a side view of the air positive electrode structure of this utility model; Figure 5 This is a schematic diagram of the upper and lower hot-pressing positions of this utility model.

[0019] The following are the labels in the diagram: 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; 61, upper hot pressing position; 62, lower hot pressing position. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Please refer to the following: Figures 1 to 5 A soft-pack zinc-air battery structure with a double-sided fixed separator includes: an upper shell 10, an air positive electrode 20, a separator 30, a negative electrode current collector 40, and a lower shell 50. The air positive electrode 20, the separator 30, and the negative electrode current collector 40 are arranged sequentially from top to bottom between the upper shell 10 and the lower shell 50.

[0022] The upper housing 10 is located at the top of the battery structure and serves as the top encapsulation structure of the battery. A venting cavity is opened in the middle, and the air positive electrode 20 is directly opposite the venting cavity of the upper housing 10 to ensure that oxygen enters the air positive electrode 20 through the venting cavity to participate in the reaction. At the same time, the edge of the upper housing 10 is aligned with the outer peripheral area of ​​the air positive electrode 20 to provide a supporting foundation for the subsequent hot pressing and fixing of the separator 30.

[0023] Both the upper shell 10 and the lower shell 50 are made of a three-layer composite film of nylon (15μm) / aluminum foil (40μm) / polyethylene (50μm), cut into a rectangle of 10cm×12cm. A 5cm×6cm breathable cavity is opened in the middle of the upper shell 10, and the edge of the cavity is 2.5cm away from the edge of the upper shell 10 to ensure sufficient space for subsequent hot pressing. The upper shell 10 and the lower shell 50 are respectively provided with upper hot pressing position 61 and lower hot pressing position 62.

[0024] The air positive electrode 20 includes: a first breathable membrane 21, a positive current collector 22, a second breathable membrane 23, and a catalyst membrane 24. These membranes are stacked sequentially from top to bottom. The first breathable membrane 21 is a PTFE waterproof and breathable membrane with a thickness of 0.12 mm, cut to 4.5 cm × 6 cm (the length near the tab of the positive current collector 22 is 0.5 cm shorter than that of the second breathable membrane 23). The second breathable membrane 23 is a polypropylene breathable membrane with a thickness of 0.06 mm, cut to 5 cm × 6 cm. The second breathable membrane 23 faces the separator 30 to isolate it from the electrolyte, preventing corrosion of the positive current collector 22 by the electrolyte. The separator 30 completely covers the air positive electrode 20, utilizing its insulation properties. Furthermore, due to the characteristics of ion conduction, the electron pathways of the positive and negative electrodes are blocked, but ions are allowed to pass through, thus achieving charge balance. The positive electrode current collector 22 is made of nickel mesh (100 mesh, 0.08 mm thick), cut into an L shape, with a main body size of 4.8 cm × 6 cm and an electrode tab section length of 2 cm and a width of 1 cm. The electrode tab section is folded 90° along the edge of the main body. The catalyst membrane 24 is based on polytetrafluoroethylene, coated with a carbon-supported platinum catalyst (platinum content 5%), with a thickness of 0.1 mm, and cut into a size of 4.5 cm × 6 cm. The first breathable membrane 21, the main body of the positive electrode current collector 22, the second breathable membrane 23, and the catalyst membrane 24 are stacked in sequence and placed in a hot press. They are hot-pressed and composited under the conditions of 90°C, 0.4 MPa, and 12 s to form an air positive electrode 20.

[0025] The catalytic membrane 24 can reduce the activation energy of the oxygen reduction reaction, accelerate the adsorption, dissociation and electron transfer process of oxygen molecules, and enable oxygen to be efficiently converted into OH⁻ (hydroxyl ions), providing sufficient OH⁻ for the zinc oxidation reaction at the negative electrode, and finally forming a complete charge cycle to ensure that the battery can output current stably.

[0026] The separator 30 is an alkaline separator (0.15mm thick, ion conductivity ≥100mS / cm), cut to 6cm×7cm. Its perimeter protrudes 0.6-1cm beyond the main body of the air positive electrode 20 (4.8cm×6cm) to ensure that it can be completely clamped by the upper and lower shells 50. This ensures complete physical isolation between the air positive electrode 20 and the current collector 40 containing the negative electrode. At the same time, it allows ions generated by the battery reaction (OH⁻ generated at the positive electrode) to migrate to the negative electrode through the pores of the separator 30, react with zinc to generate ZnO2²⁻, maintain the ion balance of the electrolyte, ensure the continuous electrochemical reaction, and achieve stable current output.

[0027] The negative electrode current collector 40 is laid flat under the diaphragm 30 and is in close contact with the diaphragm 30. Its size does not exceed the protrusion range of the diaphragm 30. The negative electrode current collector 40 is made of copper mesh (80 mesh, 0.07 mm thick), cut into 5 cm × 6 cm, and initially fixed to the inner center area of ​​the lower shell 50 by hot melt adhesive (melting point 85℃).

[0028] Zinc powder (particle size 50μm, purity 99.9%) was mixed with 6mol / L KOH electrolyte at a mass ratio of 7:3 and stirred evenly to prepare zinc paste.

[0029] Place the positive air electrode 20 inside the upper housing 10, with the main body of the positive air electrode 20 facing the vent cavity of the upper housing 10. Extend the folded electrode tabs outwards from the upper housing 10. Cover the positive air electrode 20 with the diaphragm 30, ensuring the diaphragm 30 protrudes evenly around its perimeter. Then, perform hot pressing on the edge of the upper housing 10 and the protruding area of ​​the diaphragm 30 (i.e., the upper hot pressing position 61, 4mm wide, surrounding the outer perimeter of the vent cavity) using the following parameters: temperature 90℃, pressure 0.4MPa, and time 10s. This completes the upper fixation, forming the upper composite structure. Align the lower housing 50, with the pre-fixed negative electrode current collector 40, with the upper composite structure (lower housing 50 below, diaphragm 30 above), so that the negative electrode current collector... The fluid 40 adheres to the lower surface of the separator 30, and partial hot pressing is performed on the edge of the lower housing 50 and the protruding area of ​​the separator 30 (i.e., the lower hot pressing position 62, 4mm wide, surrounding the outer perimeter of the lower housing 50). Only the left 2cm area is left unpressed (as an injection channel). The hot pressing parameters are 85℃ temperature, 0.35MPa pressure, and 8s time to form a pre-made cell bag. 5g of zinc paste is injected into the pre-made bag through the injection channel reserved on the left side of the lower housing 50 to ensure that the zinc paste completely covers the negative electrode current collector 40. Then, the injection channel area is hot-pressed and sealed with parameters of 90℃ temperature, 0.4MPa pressure, and 10s time to obtain a complete soft-pack zinc-air battery cell.

[0030] The working principle of the soft-pack zinc-air battery structure with a double-sided fixed diaphragm provided by this utility model is as follows: When the battery is running, redox reactions occur at the positive and negative electrodes respectively, and electrical energy is output through the directional migration of ions and electrons. The separator 30 covers the air positive electrode 20 and has protruding edges. It is fixed by hot pressing the edges of the upper and lower shells 50, which avoids the displacement of the separator 30 caused by traditional single-sided fixing, and ensures that the separator 30 completely blocks the electron path of the positive and negative electrodes (physical isolation). The separator 30 allows ions to pass freely, provides ion conduction channels for positive and negative electrode reactions, and maintains the charge balance inside the battery. The first breathable membrane 21 (which is thicker than the second breathable membrane 23) and the second breathable membrane 23 wrap around the positive electrode current collector 22, which not only ensures that oxygen can enter the catalyst membrane 24 smoothly, but also prevents the electrolyte from directly contacting the positive electrode current collector 22, thus avoiding corrosion of the positive electrode current collector 22. The L-shaped design of the positive electrode current collector 22 and the first breathable membrane 21 with a reduced size near the tab side of the positive electrode current collector 22 further avoids the risk of electrolyte contact caused by membrane misalignment in the tab area. The vent cavity of the upper shell 10 provides oxygen to the positive electrode, while the lower shell 50 serves as the encapsulation carrier for the zinc negative electrode. The 3-5mm wide hot-pressing area at the edges of the two (upper hot-pressing position 61 and lower hot-pressing position 62) clamps and fixes the separator 30, thereby achieving overall battery sealing and preventing electrolyte leakage.

[0031] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A soft-pack zinc-air battery structure with a separator fixed on both sides, comprising: The upper shell (10) is a soft shell with a breathable cavity; An air positive electrode (20) is disposed below the upper shell (10) and includes: a first breathable membrane (21), a positive electrode current collector (22), a second breathable membrane (23), and a catalyst membrane (24). The first breathable membrane (21), the positive electrode current collector (22), the second breathable membrane (23), and the catalyst membrane (24) are stacked sequentially from top to bottom. The first breathable membrane (21) and the second breathable membrane (23) can wrap the positive electrode current collector (22) to avoid direct contact between the positive electrode current collector (22) and the electrolyte. A diaphragm (30) covers the air positive electrode (20) and its edge protrudes from the air positive electrode (20). The negative electrode current collector (40) and the lower shell (50) are sequentially disposed below the diaphragm (30), and the edge of the diaphragm (30) is located between the hot-pressed edges of the upper shell (10) and the lower shell (50); The diaphragm (30) is fixed around its perimeter by hot pressing the edges of the upper shell (10) and the lower shell (50) to prevent the diaphragm (30) from shifting and to physically isolate the positive current collector (22) from the negative current collector (40). The area between the diaphragm (30) and the lower shell (50) is used for injecting the zinc negative electrode.

2. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The size of the first breathable membrane (21) on the tab side of the positive current collector (22) is smaller than that of the second breathable membrane (23). The positive current collector (22) is L-shaped and its size is slightly smaller than that of the second breathable membrane (23).

3. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The first breathable membrane (21) and the second breathable membrane (23) are respectively one of PTFE waterproof breathable membrane and polypropylene breathable membrane, and the thickness of the first breathable membrane (21) is greater than the thickness of the second breathable membrane (23).

4. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The positive electrode current collector (22) is a nickel mesh, copper mesh or stainless steel mesh, and the negative electrode current collector (40) is a copper mesh, tin-plated copper mesh or stainless iron.

5. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The upper shell (10) and the lower shell (50) are respectively provided with an upper hot pressing position (61) and a lower hot pressing position (62) on their edges. The diaphragm (30) is clamped and fixed by the upper shell (10) and the lower shell (50) through the hot pressing action between the upper hot pressing position (61) and the lower hot pressing position (62).

6. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 5, characterized in that, The upper shell (10) and the lower shell (50) are both made of nylon, aluminum or polyethylene composite film, and the width of the upper hot pressing position (61) and the lower hot pressing position (62) is 3-5mm.

7. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The zinc negative electrode is a mixture of zinc sheet or zinc powder and KOH electrolyte, wherein the zinc powder accounts for 60-80% of the mass of the mixture.

8. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The catalyst membrane (24) is attached to the side of the first breathable membrane (21) away from the positive electrode current collector (22), and the edge of the catalyst membrane (24) does not protrude from the edge of the first breathable membrane (21).

9. The soft-pack zinc-air battery structure with a double-sided fixed diaphragm according to claim 1, characterized in that, The diaphragm (30) is an alkaline diaphragm (30), a polypropylene diaphragm (30), or a glass fiber diaphragm (30), and the diaphragm (30) protrudes 2-5 mm from the positive electrode current collector (22).

Images