Metal-air battery and method for manufacturing the same

Abstract

The application relates to the technical field of batteries, and provides a metal-air battery and a manufacturing method thereof, the metal-air battery comprising: a plurality of bipolar plates, the plurality of bipolar plates being sequentially and layerwisely arranged; a liquid cavity, the liquid cavity being arranged between every two adjacent bipolar plates, the liquid cavity having a first side and a second side respectively facing the two adjacent bipolar plates, the first side being connected with the bipolar plate close thereto through welding sealing; and a positive plate, the positive plate being arranged between the second side and the bipolar plate close thereto, one side of the positive plate being connected with the bipolar plate through conductive glue hot-press bonding, and the other side of the positive plate being connected with the second side through alkali-resistant material sealing compression. The metal-air battery guarantees reliable sealing connection of the two sides of the liquid cavity with the bipolar plates and the positive plate, has high structural reliability, prevents electrolyte leakage, improves the cycle service life of the battery, simultaneously reduces the volume of the battery, improves energy efficiency, and is favorable for continuous production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a metal-air battery and a manufacturing method thereof. BACKGROUND

[0002] The metal-air battery is a kind of high-efficiency and environmentally friendly chemical power supply, and its principle is based on the electrochemical reaction of metal and oxygen in the air to realize the conversion of chemical energy to electrical energy. For example, zinc-air battery is considered as a potential direction of next-generation energy storage technology due to its high energy density, low raw material cost and environmental friendliness, and has broad application prospects in the fields of micro energy storage system, portable electronic equipment and Internet of Things terminal.

[0003] The traditional metal-air battery is usually assembled by mechanical pressing or sealing glue packaging. Mechanical pressing relies on physical pressure to maintain component contact, and long-term vibration or temperature fluctuation can easily cause component loosening, resulting in electrolyte leakage, low structural reliability and affecting the cycle service life. Sealing glue packaging is prone to corrosion cracking due to thermal cycling or chemical reaction, causing electrolyte leakage and short sealing life. SUMMARY

[0004] The present application provides a metal-air battery and a manufacturing method thereof to solve the problem of electrolyte leakage in the assembly method of the metal-air battery in the prior art.

[0005] The present application provides a metal-air battery and a manufacturing method thereof, comprising:

[0006] A plurality of bipolar plates, a plurality of said bipolar plates are sequentially stacked;

[0007] A liquid cavity is provided between each adjacent two said bipolar plates, said liquid cavity has a first side and a second side respectively facing two adjacent said bipolar plates, and said first side is connected with said bipolar plate close to it by welding sealing;

[0008] A positive plate is provided between said second side and said bipolar plate close to it, one side of said positive plate is connected with said bipolar plate by conductive glue hot pressing, and the other side of said positive plate is connected with said second side by alkali-resistant material sealing pressing.

[0009] According to the metal-air battery provided by the present application, further comprising:

[0010] A negative metal plate is provided between said first side and said bipolar plate close to it, and said negative metal plate is connected with said bipolar plate by conductive glue hot pressing.

[0011] According to the metal-air battery provided by the present application, the outer periphery of the negative metal plate is pressed between the liquid cavity and the bipolar plate.

[0012] According to a metal-air battery provided by the present invention, the bipolar plate for welding to the liquid cavity comprises: a plate body and a conductive metal foil, the conductive metal foil and the plate body being hot-pressed together by the conductive adhesive, the conductive metal foil being coated with a negative electrode metal paste, the negative electrode metal paste being accommodated in a receiving space formed by the conductive metal foil, the liquid cavity, and the positive electrode sheet;

[0013] A diaphragm is provided between the positive electrode sheet and the liquid cavity adjacent thereto. One side of the diaphragm is sealed and pressed with the positive electrode sheet via an alkali-resistant material, and the other side of the diaphragm is sealed and pressed with the second side via an alkali-resistant material.

[0014] According to a metal-air battery provided by the present invention, the alkali-resistant material is hot melt adhesive, alkali-resistant adhesive or carbon fiber board.

[0015] According to a metal-air battery provided by the present invention, a gas flow channel is provided on the bipolar plate adjacent to the positive electrode sheet, and the gas flow channel is located on a side of the bipolar plate close to the positive electrode sheet.

[0016] According to a metal-air battery provided by the present invention, the multiple bipolar plates include: a first bipolar plate, a second bipolar plate and a third bipolar plate, at least one of the third bipolar plates is stacked between the first bipolar plate and the second bipolar plate, and the first bipolar plate and the second bipolar plate are provided with an inspection structure.

[0017] The present invention also provides a method for manufacturing a metal-air battery, comprising the steps of:

[0018] Sealing and connecting the first bipolar plate to the first side of a liquid chamber by welding to obtain a first assembly;

[0019] hot-pressing the second bipolar plate to a positive electrode sheet using a conductive adhesive to obtain a second assembly;

[0020] hot-pressing one side of a third bipolar plate to a positive electrode sheet using a conductive adhesive, and sealingly connecting the other side of the third bipolar plate to a first side of a liquid chamber by welding to obtain a third assembly;

[0021] The second side of the liquid cavity in the first component and the positive electrode sheet in the third component are sealed and pressed together through alkali-resistant material, and the second side of the liquid cavity in the third component and the positive electrode sheet in the second component are sealed and pressed together through alkali-resistant material.

[0022] According to a metal-air battery manufacturing method provided by the present invention, before sealingly connecting the first bipolar plate to the first side of a liquid chamber by welding, the method further comprises: hot-pressing the first bipolar plate to a negative electrode metal sheet by conductive adhesive;

[0023] Before the other side of the third bipolar plate is sealed and connected with the first side of a liquid cavity by welding, the other side of the third bipolar plate is hot-pressed and connected with a negative metal sheet through the conductive adhesive.

[0024] According to the metal-air battery manufacturing method provided by the application, a plurality of third components are manufactured, and the plurality of third components are arranged in layers between the first component and the second component, and each adjacent two third components are sealed and connected through an alkali-resistant material.

[0025] The metal-air battery and the manufacturing method thereof provided by the application ensure reliable sealing connection of the two sides of the liquid cavity with the bipolar plate and the positive sheet respectively by welding one side of the liquid cavity with the bipolar plate, hot-pressing and connecting the other side of the liquid cavity with the positive sheet through the alkali-resistant material, and hot-pressing and connecting the positive sheet with the bipolar plate through the conductive adhesive, and the structure has high reliability, prevents electrolyte leakage, and improves the cycle service life of the battery. The welding of the liquid cavity and the bipolar plate does not need to additionally arrange sealing adhesive, the high-strength adhesion of the conductive adhesive can realize the close connection of the positive sheet and the bipolar plate and reduce the thickness of the adhesive layer, thereby reducing the volume of the battery. The thinner thickness of the conductive adhesive can avoid overflow and shorten the curing time, which is beneficial to continuous production. The conductive adhesive can also reduce the internal resistance loss of the battery and improve the energy efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0027] Figure 1 is one of the explosion structure schematic diagrams of the metal-air battery provided by the application.

[0028] Figure 2 is Figure 1 is another perspective view of the explosion structure of the metal-air battery in the embodiment.

[0029] Figure 3 is one of the component explosion schematic diagrams of the explosion structure of the metal-air battery provided by the application.

[0030] Figure 4 is another perspective view of the explosion structure schematic diagram of the metal-air battery provided by the application.

[0031] Figure 5 is Figure 4 is another perspective view of the explosion structure of the metal-air battery in the embodiment.

[0032] Figure 6 is the second assembly explosion schematic diagram of the explosion structure of the metal air battery provided by the present application.

[0033] Reference signs:

[0034] 1, bipolar plate; 11, plate body; 12, conductive metal foil; 13, gas flow channel; 1a, first bipolar plate; 1b, second bipolar plate; 1c, third bipolar plate; 2, liquid cavity; 21, first side; 22, second side; 3, positive electrode sheet; 4, negative metal sheet; 5, negative metal paste; 6, diaphragm; 100, first assembly; 200, second assembly; 300, third assembly. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "first", "second", "third" are numbered for the purpose of clearly explaining the components of the product, and do not represent any substantial difference. The terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances. In addition, the meaning of "multiple" is two or more.

[0037] The metal air battery and the manufacturing method thereof of the present application will be described below in combination with Figures 1-6

[0038] As shown in Figure 1 and Figure 2 , the metal air battery provided by the embodiments of the present application comprises a liquid cavity 2, a positive electrode sheet 3 and a plurality of bipolar plates 1. The plurality of bipolar plates 1 are sequentially stacked. There is a liquid cavity 2 between each adjacent two bipolar plates 1. The liquid cavity 2 has a first side 21 and a second side 22 facing the adjacent two bipolar plates 1 respectively, the first side 21 is sealingly connected with the bipolar plate 1 close to it by welding, and the second side 22 is provided with the positive electrode sheet 3 between the bipolar plate 1 close to it. One side of the positive electrode sheet 3 is hot-pressed and bonded with the bipolar plate 1 through conductive adhesive, and the other side of the positive electrode sheet 3 is sealingly bonded with the second side 22 through alkali-resistant material.

[0039] Among them, the liquid cavity 2 is a ring structure, as shown in​Figure 1 As shown in the rectangular ring structure, the two sides of the liquid cavity 2 are connected with the bipolar plate 1 and the positive plate 3 respectively to form a containing space. The two sides of the liquid cavity 2 are parallel to each other, so that the thickness of the containing space is uniform, and the stability of the electrolyte distribution is optimized. The positive plate 3 is connected with another bipolar plate 1 away from the liquid cavity 2, and the another bipolar plate 1 is used to provide structural support for the positive plate 3. The liquid cavity 2 is provided with a liquid injection port, and the electrolyte is injected into the containing space through the liquid injection port.

[0040] The metal-air battery can be a zinc-air battery, a lithium-air battery, or a magnesium-air battery, etc. Taking the zinc metal-air battery as an example, the electrolyte includes but is not limited to water-based solvents such as KOH and (CH3COO)2Zn. Optionally, the concentration of KOH is selected as 6 mol / L, and the concentration of (CH3COO)2Zn is 0.2 mol / L.

[0041] The number of bipolar plates 1 is at least two. When the number of bipolar plates 1 is two, there is a liquid cavity 2 between the two bipolar plates 1, and a positive plate 3 is arranged between the liquid cavity 2 and one of the bipolar plates 1, thereby forming a metal-air battery structure with only a single cell. When a battery with larger capacity is needed, more bipolar plates 1 can be arranged, and a liquid cavity 2 and a positive plate 3 are arranged between each adjacent two bipolar plates 1, thereby forming a metal-air battery structure with multiple cells connected in series, and each adjacent two cells share one bipolar plate 1. The side of the bipolar plate 1 used to connect the positive plate 3 is defined as the positive side, and the side used to connect the negative metal is defined as the negative side.

[0042] The liquid cavity 2 and the bipolar plate 1 are connected by welding, which can ensure reliable sealing connection and is not easy to cause the components to loosen due to long-term vibration or temperature fluctuations. Optionally, the material of the liquid cavity 2 is transparent or translucent polypropylene material, and the material of the bipolar plate 1 is non-transparent polypropylene-based composite material, which can be welded from the side of the liquid cavity 2 by laser welding process. The bipolar plate 1 and the liquid cavity 2 can also be polyolefin-based, fluoropolymer-based or modified material combinations, or other materials suitable for laser welding.

[0043] It should be noted that the liquid cavity 2 and the bipolar plate 1 are not limited to welding by laser welding process, but can also be welded by thermoplastic welding process. The material of the bipolar plate 1 and the liquid cavity 2 is not limited in the embodiment of the present application, and can be selected according to actual conditions and needs, as long as the material of the joint surface of the bipolar plate 1 and the liquid cavity 2 is suitable for the corresponding welding process.

[0044] The positive electrode sheet 3, serving as the air electrode, can be made of carbon paper, such as Freudenberg model H24CX483. Its surface contains polytetrafluoroethylene (PTFE). PTFE has hydrophobic properties, which can reduce the hydrophilicity of the carbon paper surface, making it hydrophobic and effectively isolating the electrolyte, allowing only air to pass through. Of course, the positive electrode sheet 3 can also be made of other carbon-based or non-carbon materials, and this embodiment of the present invention is not limited to this.

[0045] The joint surface between the liquid cavity 2 and the positive electrode sheet 3 is sealed and pressed by an alkali-resistant material. Optionally, the alkali-resistant material is a hot melt adhesive, an alkali-resistant adhesive or a carbon fiber plate. Among them, the hot melt adhesive uses an alkali-resistant hot melt adhesive, and the hot melt adhesive or the carbon fiber plate is sealed and joined to the liquid cavity 2 and the positive electrode sheet 3 through a hot pressing process. The alkali-resistant adhesive is sealed and joined to the liquid cavity 2 and the positive electrode sheet 3 through a normal temperature pressing process. Of course, the embodiment of the present invention does not impose any specific restrictions on the alkali-resistant material, and it can be selected according to actual conditions and needs, as long as it can meet the requirements of not reacting with the electrolyte and can achieve a sealed joint between the liquid cavity 2 and the positive electrode sheet 3.

[0046] The side of the positive electrode sheet 3 facing away from the liquid chamber 2 is hot-pressed with the bipolar plate 1 using conductive adhesive. Conductive adhesive is a material that combines both electrical conductivity and adhesive properties. It reduces the internal resistance loss of the battery during charge and discharge, improving energy efficiency. Furthermore, conductive adhesive has high bonding strength, significantly reducing the thickness of the adhesive layer to prevent overflow. Its short curing time makes it easily adaptable to continuous production and facilitates miniaturized battery design.

[0047] The metal-air battery provided by the embodiment of the present invention ensures that the two sides of the liquid chamber 2 are reliably sealed and connected to the bipolar plate 1 and the positive electrode 3 respectively by welding one side of the liquid chamber 2 to the bipolar plate 1, sealing and pressing the other side of the liquid chamber 2 to the positive electrode 3 with an alkali-resistant material, and hot-pressing the positive electrode 3 to the bipolar plate 1 with a conductive adhesive. This ensures high structural reliability, prevents electrolyte leakage, and improves the cycle life of the battery. The welding of the liquid chamber 2 and the bipolar plate 1 does not require the use of additional sealant. The high-strength adhesion of the conductive adhesive can achieve a tight connection between the positive electrode 3 and the bipolar plate 1 and reduce the thickness of the adhesive layer, thereby reducing the volume of the battery. The thinner conductive adhesive thickness can avoid glue overflow and shorten the curing time, which is conducive to continuous production. The conductive adhesive can also reduce the internal resistance loss of the battery and improve energy efficiency. The metal-air battery provided by the embodiment of the present invention provides a lightweight, long-lasting power supply solution, while laying a key technical foundation for the large-scale application of metal-air batteries under complex working conditions.

[0048] Experimental verification shows that compared with metal-air batteries with traditional structures, the metal-air battery provided by the embodiment of the present invention has an electrolyte leakage rate reduced from 5% to less than 0.5%, and its lifespan is significantly improved; the volume is reduced by 15%, and the thickness is thinned by 15%; the use of laser welding technology shortens the assembly cycle by 30% compared to manual mechanical pressing.

[0049] The metal-air battery provided in this embodiment of the present invention also includes a negative electrode metal sheet 4. The negative electrode metal sheet 4 is disposed between the first side 21 of the liquid chamber 2 and the bipolar plate 1 adjacent thereto. The negative electrode metal sheet 4 is thermocompressed to the bipolar plate 1 using conductive adhesive. Specifically, the negative electrode side of the bipolar plate 1 is thermocompressed to the negative electrode metal sheet 4 and welded to the liquid chamber 2 using conductive adhesive. The positive electrode side of the bipolar plate 1 is thermocompressed to the positive electrode sheet 3 using conductive adhesive.

[0050] Optionally, the negative electrode metal sheet 4 can be made of zinc, lithium, or magnesium. The negative electrode metal sheet 4 is hot-pressed to the bipolar plate 1 using conductive adhesive, which reduces internal resistance losses during the battery's charge and discharge processes and improves energy efficiency. High-strength conductive adhesive significantly reduces adhesive layer thickness to prevent overflow, and its short curing time makes it easily adaptable to continuous production, facilitating miniaturized battery design.

[0051] It should be noted that if the bipolar plate 1 is made of a material that does not react with the electrolyte, such as a polypropylene bipolar plate, the negative electrode metal sheet 4 may not be provided. During battery charging, the metal ions in the electrolyte are reduced and adhere to the polypropylene bipolar plate, followed by discharge.

[0052] like Figure 1 and Figure 2 As shown in , in some embodiments of the present invention, the outer peripheral edge of the negative electrode metal sheet 4 is pressed between the liquid cavity 2 and the bipolar plate 1. In this way, the negative electrode metal sheet 4 can cover the inner frame area of ​​the liquid cavity 2, so that the electrolyte is distributed more evenly, and at the same time the weight of the negative electrode metal sheet can be reduced. It can be understood that the outer peripheral area of ​​the negative electrode metal sheet 4 is larger than the inner frame area of ​​the liquid cavity 2 and smaller than the outer frame area of ​​the liquid cavity 2, that is, the negative electrode metal sheet 4 covers a part of the joint surface between the liquid cavity 2 and the bipolar plate 1 to ensure that the welding area between the liquid cavity 2 and the bipolar plate 1 is in a complete "U" shape, so as to ensure that when the battery is over-discharged, there is still a reliable sealed connection between the liquid cavity 2 and the bipolar plate 1 to avoid leakage of electrolyte.

[0053] like Figure 4 and Figure 5As shown in the figures, in some embodiments of the application, the bipolar plate 1 for welding with the liquid cavity 2 comprises a plate body 11 and a conductive metal foil 12. The conductive metal foil 12 is hot-pressed and bonded with the plate body 11 by conductive glue, and the conductive metal foil 12 is coated with a negative metal paste 5. The negative metal paste 5 is accommodated in the accommodation space formed by the conductive metal foil 12, the liquid cavity 2 and the positive sheet 3. A diaphragm 6 is arranged between the positive sheet 3 and the liquid cavity 2 close to it, one side of the diaphragm 6 is sealed and bonded with the positive sheet 3 by alkali-resistant material, and the other side of the diaphragm 6 is sealed and bonded with the second side 22 of the liquid cavity 2 by alkali-resistant material.

[0054] It can be understood that the conductive metal foil 12 is located between the plate body 11 and the liquid cavity 2, the liquid cavity 2 is located between the conductive metal foil 12 and the positive sheet 3, and the three form an accommodation space, and the negative metal paste 5 is attached to the conductive metal foil 12 and located in the accommodation space. In this way, the negative metal paste 5 can be provided with a certain thickness, such as 80% of the thickness of the liquid cavity 2. In this way, more volume of negative metal paste 5 can be accommodated, and the capacity of the metal-air battery is increased.

[0055] The conductive metal foil 12 can be a tin-plated copper foil, an indium-plated copper foil, a tin-plated stainless steel foil or an indium-plated stainless steel foil, etc. The negative metal paste 5 can be a zinc paste. The zinc paste contains zinc powder, high-concentration KOH electrolyte, gelling agent and corrosion inhibitor. The metal plating layer on the conductive metal foil 12 is used to prevent the conductive metal foil 12 from reacting with metal ions in the electrolyte. The diaphragm 6 is a carboxylated non-woven diaphragm with hydrophilicity, and the diaphragm 6 arranged between the positive sheet 3 and the liquid cavity 2 can effectively isolate the positive and negative electrodes while realizing the transmission of electrolyte and air. The hot-pressed and bonded conductive metal foil 12 and plate body 11 by conductive glue can reduce the internal resistance loss of the battery during charging and discharging, and improve the energy efficiency. The high-adhesion-strength conductive glue can greatly reduce the thickness of the glue layer to avoid glue overflow, and has a short curing time, which is easy to adapt to continuous production and is conducive to the miniaturization design of the battery volume.

[0056] In the case that the materials of the liquid cavity 2 and the bipolar plate 1 meet direct welding, such as the liquid cavity 2 and the bipolar plate 1 are both polypropylene-based materials, the coverage area of the conductive metal foil 12 can be set to be smaller than the outer frame area of the liquid cavity 2, that is, the outer periphery of the conductive metal foil 12 and the diaphragm 6 is pressed and arranged between the liquid cavity 2 and the conductive metal foil 12, and the first side 21 of the liquid cavity 2 is welded with the bipolar plate 1 in the "h" type area.

[0057] In the case that the materials of the liquid cavity 2 and the bipolar plate 1 do not meet direct welding, such as the liquid cavity 2 is a polypropylene material and the bipolar plate 1 is a graphite material, the coverage area of the conductive metal foil 12 can be set to be larger than the outer frame area of the liquid cavity 2, and the first side 21 of the liquid cavity 2 is sealed and connected with the conductive metal foil 12 by laser welding.

[0058] Furthermore, the outer peripheral edge of the diaphragm 6 is pressed between the liquid cavity 2 and the positive electrode sheet 3. In this way, the diaphragm 6 can cover the inner frame area of ​​the liquid cavity 2, making the air distribution more uniform. It can be understood that the outer peripheral area of ​​the diaphragm 6 is larger than the inner frame area of ​​the liquid cavity 2 and smaller than the outer frame area of ​​the liquid cavity 2, that is, the diaphragm 6 covers a portion of the joint surface between the liquid cavity 2 and the positive electrode sheet 3 to ensure that the sealed pressing area between the liquid cavity 2 and the positive electrode sheet 3 is a complete "U" shape. This can prevent the diaphragm 6 from diverting the electrolyte out of the liquid cavity 2 and avoiding electrolyte leakage.

[0059] In the embodiment of the present invention, a gas flow channel 13 is provided on the bipolar plate 1 adjacent to the positive electrode sheet 3 . The gas flow channel 13 is located on a side of the bipolar plate 1 close to the positive electrode sheet 3 .

[0060] Specifically, if Figure 2 As shown, the positive electrode side of the bipolar plate 1 is provided with a gas flow channel 13. The gas flow channel is a groove formed in the bipolar plate 1 and extends through both ends of the bipolar plate 1. The bipolar plate 1 is provided with multiple parallel and spaced gas flow channels 13. After the positive electrode sheet 3 and the bipolar plate 1 are thermally pressed together using conductive adhesive, multiple parallel airflow channels are formed between the positive electrode sheet 3 and the bipolar plate 1 for air circulation. The gas flow channels can be linear or curved, and this embodiment does not impose any specific limitations on this.

[0061] In a specific embodiment of the present invention, see Figure 1 、 Figure 2 、 Figure 4 and Figure 5 The plurality of bipolar plates 1 include a first bipolar plate 1a, a second bipolar plate 1b, and a third bipolar plate 1c. At least one third bipolar plate 1c is stacked between the first bipolar plate 1a and the second bipolar plate 1b. Inspection structures are provided on the first bipolar plate 1a and the second bipolar plate 1b to monitor the status of the metal-air battery, such as temperature and pressure.

[0062] It can be understood that the metal-air battery of this embodiment includes at least three bipolar plates 1 , at least two liquid chambers 2 and at least two positive electrode sheets 3 , and in some embodiments also includes at least two negative electrode metal sheets 4 .

[0063] As a specific embodiment, when the number of the third bipolar plate 1c is one, the number of the liquid cavity 2, the positive electrode sheet 3 and the negative electrode metal sheet 4 is two. One of the liquid cavities 2 is arranged between the first bipolar plate 1a and the third bipolar plate 1c, and the other liquid cavity 2 is arranged between the second bipolar plate 1b and the third bipolar plate 1c, and one negative electrode metal sheet 4 and one positive electrode sheet 3 are arranged on the two sides of each liquid cavity 2. The first side 21 of each liquid cavity 2 is welded with the joint surface of the bipolar plate 1 close to it, and one positive electrode sheet 3 is arranged between the second side 22 of each liquid cavity 2 and the bipolar plate 1 close to it. One side of each positive electrode sheet 3 is hot-pressed and bonded with the joint surface of the bipolar plate 1 through conductive glue, and the other side is sealed and bonded with the joint surface of the second side 22 of the liquid cavity 2 through alkali-resistant material. In this way, the metal-air battery structure of two series-connected batteries is formed.

[0064] Referring to Figure 1 and Figure 2 , as another specific embodiment, the number of the third bipolar plate 1c is two, and the number of the corresponding liquid cavity 2, the positive electrode sheet 3 and the negative electrode metal sheet 4 is three. The liquid cavity 2 closest to the first bipolar plate 1a is provided with one negative electrode metal sheet 4 between the first bipolar plate 1a, the liquid cavity 2 closest to the second bipolar plate 1b is provided with one positive electrode sheet 3 between the second bipolar plate 1b, and one positive electrode sheet 3, one third bipolar plate 1c and one negative electrode metal sheet 4 are arranged between every two adjacent liquid cavities 2. The connection relationship between the bipolar plate 1, the negative electrode metal sheet 4, the liquid cavity 2 and the positive electrode sheet 3 is described in the above embodiment, and will not be described again.

[0065] It should be noted that the negative electrode metal sheet 4 in the above-mentioned embodiments can be replaced by the conductive metal foil 12 and the negative electrode metal paste 5, and the diaphragm 6 is arranged between the adjacent liquid cavities 2 and the positive electrode sheets 3.

[0066] The embodiment of the present application also provides a metal-air battery manufacturing method, which can be applied to the metal-air battery described in any of the above embodiments, and comprises the following steps:

[0067] Step S1, sealingly connecting the first side 21 of one liquid cavity 2 and the first bipolar plate 1a by welding to obtain a first assembly 100, referring to Figure 3 and Figure 6 .

[0068] Step S2, hot-press bonding one positive electrode sheet 3 and the second bipolar plate 1b through conductive glue to obtain a second assembly 200, referring to Figure 3 and Figure 6 .

[0069] Step S3, hot-press bonding one side of the third bipolar plate 1c and one positive electrode sheet 3 through conductive glue, and sealingly connecting the other side of the third bipolar plate 1c and the first side 21 of one liquid cavity 2 by welding to obtain a third assembly 300, referring toFigure 3 and Figure 6 .

[0070] Step S4, the second side 22 of the liquid cavity 2 in the first assembly 100 and the positive plate 3 in the third assembly 300 are sealed and pressed by the alkali-resistant material, and the second side 22 of the liquid cavity 2 in the third assembly 300 and the positive plate 3 in the second assembly 200 are sealed and pressed by the alkali-resistant material.

[0071] In step S1, the negative side of the first bipolar plate 1a is first attached to the first side 21 of a liquid cavity 2, and then the two are welded to form a sealed connection, thereby obtaining the first assembly 100.

[0072] In step S2, conductive glue is first applied to the positive side of the second bipolar plate 1b, and then the positive plate 3 is attached thereto and hot-pressed to form a joint, thereby obtaining the second assembly 200. For example, hot pressing at 70°C for 15 minutes.

[0073] Step S3 specifically includes: step S31, conductive glue is applied to the positive side of the third bipolar plate 1c, and the positive plate 3 is attached thereto and hot-pressed to form a joint. For example, hot pressing at 70°C for 15 minutes. Step S32, the negative side of the third bipolar plate 1c and the first side 21 of a liquid cavity 2 are sealed and connected by welding. Among them, step S31 and step S32 do not have a specific order.

[0074] Among them, the specific welding process in steps S1 and S32 can be determined according to the material of the corresponding liquid cavity 2 and bipolar plate 1, such as laser welding or thermoplastic welding. For example, in the case of a non-transparent polypropylene-based composite material for the bipolar plate 1 and a transparent polypropylene material for the liquid cavity 2, laser welding or thermoplastic welding can be used. For another example, in the case of non-transparent polypropylene materials for both the bipolar plate 1 and the liquid cavity 2, thermoplastic welding can be used.

[0075] Before performing the welding operation in steps S1 and S32, the first side 21 of the liquid cavity 2 is roughened and surface treated with an auxiliary agent to improve the welding effect.

[0076] Step S4 includes: step S41, the second side 22 of the liquid cavity 2 in the first assembly 100 and the positive plate 3 in the third assembly 300 are sealed and pressed by the alkali-resistant material. Step S42, the second side 22 of the liquid cavity 2 in the third assembly 300 and the positive plate 3 in the second assembly 200 are sealed and pressed by the alkali-resistant material. Among them, step S41 and step S42 do not have a specific order.

[0077] The above steps S1, S2 and S3 do not have a specific order and can be performed in a single line or in multiple lines simultaneously. After the first assembly 100, the second assembly 200 and the third assembly 300 are completed, step S4 is performed.

[0078] The traditional metal-air battery structure needs to connect multiple parts in the order of bipolar plate 1, liquid cavity 2, and positive plate 3, that is, to be made layer by layer, which has low production efficiency. The metal-air battery structure is divided into three components, first component 100, second component 200, and third component 300. The three components can be obtained by three independent process steps S1, S2, and S3, and then the three components are sealed and pressed by hot pressing of alkali-resistant material, which improves the production efficiency. In actual production, the three components can be stored separately, and by adjusting the number of the third component 300, metal-air batteries of different capacity specifications can be easily produced.

[0079] In the case where the metal-air battery further includes a negative metal sheet 4, before the first bipolar plate 1a and the first side 21 of a liquid cavity 2 are connected by welding sealing in step S1, the first bipolar plate 1a and a negative metal sheet 4 are hot-pressed and connected by conductive glue. Before the other side of the third bipolar plate 1c and the first side 21 of a liquid cavity 2 are connected by welding sealing in step S3, the other side of the third bipolar plate 1c and a negative metal sheet 4 are hot-pressed and connected by conductive glue.

[0080] In the case where the material of the bipolar plate 1 and the liquid cavity 2 meets direct welding, after the negative metal sheet 4 and the bipolar plate 1 are hot-pressed and connected by conductive glue, the liquid cavity 2 and the bipolar plate 1 are directly welded. In the case where the material of the bipolar plate 1 and the liquid cavity 2 does not meet direct welding, for example, the bipolar plate 1 is graphite material and the liquid cavity 2 is polypropylene material, after the negative metal sheet 4 and the bipolar plate 1 are hot-pressed and connected by conductive glue, the first side 21 of the liquid cavity 2 and the conductive metal foil 12 in the negative metal sheet 4 are welded.

[0081] Step S1 specifically includes: step S11, hot-pressing and connecting the negative side of the first bipolar plate 1a and a negative metal sheet 4 by conductive glue. Specifically, the conductive glue is applied to the negative side of the first bipolar plate 1a, and a negative metal sheet 4 is attached thereto and hot-pressed and connected. Step S12, the negative side of the first bipolar plate 1a and the first side 21 of a liquid cavity 2 are attached, and then welded to form a sealed connection. After step S11 is completed, step S12 is performed to obtain the first component 100.

[0082] Before the other side of the third bipolar plate 1c is connected to the first side 21 of the liquid chamber 2 by welding and sealing in step S3, the method further comprises: in step S31, conductive glue is applied to the positive side of the third bipolar plate 1c, and the positive plate 3 is attached to the positive side and hot-pressed to form a joint. In step S33, conductive glue is applied to the negative side of the third bipolar plate 1c, and the negative metal plate 4 is attached to the negative side and hot-pressed to form a joint. Steps S31 and S33 are not in a specific order. After steps S31 and S33 are completed, a three-in-one structure of the bipolar plate 1, the positive plate 3 and the negative metal plate 4 is formed, and then step S32 is performed to weld and seal the three-in-one structure to the liquid chamber 2.

[0083] It should be noted that when the negative metal plate 4 in the above embodiment is replaced by the conductive metal foil 12 and the negative metal paste 5, and the separator 6 is arranged between the adjacent liquid chamber 2 and the positive plate 3, the specific steps of steps S1, S2 and S3 need to be adjusted accordingly. Before the first bipolar plate 1a is connected to the first side 21 of the liquid chamber 2 by welding and sealing in step S1, it further comprises: a plate body 11 is hot-pressed to a conductive metal foil 12 by conductive glue to obtain the first bipolar plate 1a; and the negative metal paste 5 is coated on the conductive metal foil 12 of the first bipolar plate 1a. Step S2 specifically comprises: the second bipolar plate 1b is hot-pressed to a positive plate 3 by conductive glue, and the side of the positive plate 3 away from the second bipolar plate 1b is hot-pressed to a separator 6 by an alkali-resistant material to obtain the second assembly 200. Before the side of the third bipolar plate 1c is hot-pressed to a positive plate 3 by conductive glue in step S3, it further comprises: a plate body 11 is hot-pressed to a conductive metal foil 12 by conductive glue to obtain the third bipolar plate 1c; and the negative metal paste 5 is coated on the conductive metal foil 12 of the third bipolar plate 1c.

[0084] On the basis of the above embodiment, the metal-air battery manufacturing method further comprises: manufacturing a plurality of third assemblies 300, and stacking the plurality of third assemblies 300 between the first assembly 100 and the second assembly 200, and hot-pressing an alkali-resistant material between each adjacent two third assemblies 300.

[0085] Specifically, step S3 is repeated multiple times to obtain a plurality of third assemblies 300. When the number of third assemblies 300 is two, referring to Figure 1 and Figure 2When the number of the third assembly 300 is three, a metal-air battery structure of three batteries connected in series can be obtained. By analogy, different numbers of the third assembly 300 are selected according to different battery capacities. The first assembly 100, the third assembly 300 and the second assembly 200 are sequentially sealed and pressed by the alkali-resistant material in order, or the second assembly 200, the third assembly 300 and the first assembly 100 are sequentially sealed and pressed by the alkali-resistant material in order.

[0086] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions described in the foregoing examples can still be modified, or some technical features therein can be replaced by equivalents; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for manufacturing a metal-air battery, characterized in that: The metal-air battery comprises: a plurality of bipolar plates, including a first bipolar plate, a second bipolar plate, and a third bipolar plate, wherein at least one third bipolar plate is stacked between the first bipolar plate and the second bipolar plate; A liquid cavity is provided between each two adjacent bipolar plates, the liquid cavity having a first side and a second side facing the two adjacent bipolar plates respectively, the first side being sealed and connected to the adjacent bipolar plate by welding; A positive electrode sheet, wherein the positive electrode sheet is provided between the second side and the bipolar plate adjacent thereto, one side of the positive electrode sheet being hot-pressed and bonded to the bipolar plate by conductive adhesive, and the other side of the positive electrode sheet being sealed and pressed with an alkali-resistant material; The metal-air battery manufacturing method comprises the following steps: Sealing and connecting the first bipolar plate to the first side of a liquid chamber by welding to obtain a first assembly; hot-pressing the second bipolar plate to a positive electrode sheet using a conductive adhesive to obtain a second assembly; hot-pressing one side of a third bipolar plate to a positive electrode sheet using a conductive adhesive, and sealingly connecting the other side of the third bipolar plate to a first side of a liquid chamber by welding to obtain a third assembly; The second side of the liquid cavity in the first component and the positive electrode sheet in the third component are sealed and pressed together through alkali-resistant material, and the second side of the liquid cavity in the third component and the positive electrode sheet in the second component are sealed and pressed together through alkali-resistant material.

2. The method for manufacturing a metal-air battery according to claim 1, wherein: Also includes: A negative electrode metal sheet is provided between the first side and the bipolar plate adjacent thereto, and the negative electrode metal sheet is hot-pressed and bonded to the bipolar plate by conductive adhesive.

3. The method for manufacturing a metal-air battery according to claim 2, wherein: The outer periphery of the negative electrode metal sheet is pressed between the liquid cavity and the bipolar plate.

4. The method for manufacturing a metal-air battery according to claim 1, wherein: The bipolar plate for welding to the liquid cavity comprises: a plate body and a conductive metal foil, the conductive metal foil and the plate body being hot-pressed together by the conductive adhesive, the conductive metal foil being coated with a negative electrode metal paste, the negative electrode metal paste being accommodated in a receiving space formed by the conductive metal foil, the liquid cavity, and the positive electrode sheet; A diaphragm is provided between the positive electrode sheet and the liquid cavity adjacent thereto. One side of the diaphragm is sealed and pressed with the positive electrode sheet via an alkali-resistant material, and the other side of the diaphragm is sealed and pressed with the second side via an alkali-resistant material.

5. The method for manufacturing a metal-air battery according to claim 1, wherein: The alkali-resistant material is hot melt adhesive, alkali-resistant adhesive or carbon fiber plate.

6. The method for manufacturing a metal-air battery according to claim 1, wherein: A gas flow channel is provided on the bipolar plate adjacent to the positive electrode sheet, and the gas flow channel is located on a side of the bipolar plate close to the positive electrode sheet.

7. The method for manufacturing a metal-air battery according to any one of claims 1 to 6, wherein: The plurality of bipolar plates include: the first bipolar plate and the second bipolar plate are provided with inspection structures.

8. The method for manufacturing a metal-air battery according to claim 1, wherein: Before the first bipolar plate is sealed and connected to the first side of a liquid cavity by welding, the method further comprises: hot-pressing and bonding the first bipolar plate to a negative electrode metal sheet by using a conductive adhesive; Before the other side of the third bipolar plate is sealed and connected to the first side of a liquid cavity by welding, the method further includes: hot-pressing the other side of the third bipolar plate to a negative electrode metal sheet by using the conductive adhesive.

9. The method for manufacturing a metal-air battery according to claim 1 or 8, wherein: A plurality of the third components are manufactured and stacked between the first component and the second component, and each two adjacent third components are sealed and pressed together by an alkali-resistant material.

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