Catalyst material for metal-air battery as well as preparation method and application of catalyst material

Abstract

The invention discloses a catalyst material for a metal-air battery and a preparation method and application thereof, and belongs to the technical field of metal-air batteries, and the method comprises the following steps: dissolving polyacrylonitrile in N, N-dimethylformamide, uniformly stirring, and carrying out electrostatic spinning, drying and heat treatment to obtain carbon nanofibers; the preparation method comprises the following steps: dissolving carbon nanofibers, cobalt chloride hexahydrate, nickel chloride hexahydrate and sodium hydroxide in ethylene glycol to obtain a mixed solution, and carrying out hydrothermal reaction, washing and drying to obtain the catalyst material for the metal-air battery. The cobalt-nickel alloy is used as an active part to promote the electrochemical reaction in the metal-air battery. The cobalt-nickel alloy is loaded on polyacrylonitrile to form a cross-linked structure, so that the catalyst has a larger specific surface area, more catalytic active sites are provided, the unique and stable three-dimensional catalytic structure is beneficial to permeation of electrolyte and transmission of ions, and the reaction rate, catalytic efficiency and conductivity of the metal-air battery are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal-air batteries, and in particular relates to a catalyst material for metal-air batteries, a preparation method thereof, and an application thereof. Background Art

[0002] Metal-air batteries (MEBs) use lightweight active metals as anode materials and oxygen from air as the cathode active material. They offer advantages such as high energy density, smooth discharge, and environmental friendliness, making them an advanced energy technology that combines energy and environmental benefits. Compared to traditional lithium-ion batteries, the cathode material of metal-air batteries does not need to be stored within the battery, significantly reducing battery weight. They also possess extremely high theoretical specific capacity, reaching several or even dozens of times that of lithium-ion batteries. However, MEBs still face numerous challenges in practical application. First, the battery's rate capability and cycle life are limited by the catalytic activity and stability of the cathode material. Second, during charge and discharge, the oxygen reduction and evolution reactions (ORR and OER) are kinetically slow, requiring large amounts of catalyst to maintain high reaction rates. Furthermore, existing catalysts often contain precious metals or toxic transition metals, which are not only costly but also pose environmental and safety risks. Finally, the interfacial contact between the electrolyte and catalyst, as well as the stability of the electrode material, also significantly influence battery performance.

[0003] Chinese patent application publication number CN114824328A discloses a photosensitive low-temperature metal-air battery pack, comprising a plurality of photosensitive low-temperature metal-air batteries connected in parallel or in series. Each photosensitive low-temperature metal-air battery comprises a photosensitive positive electrode, a diaphragm or solid electrolyte soaked in electrolyte, and a metal negative electrode. The photosensitive positive electrode is composed of a photocathode catalyst and a positive electrode current collector, wherein the photocathode catalyst is a catalyst composited with metal nanoparticles and a conductive substrate, has a full-spectrum absorption response, and has excellent photothermal conversion capabilities, and can catalyze oxygen reduction and precipitation reactions. However, this patent application still has the problem that the preparation method of the photocathode catalyst needs to be further optimized. Chinese patent application publication number CN111370706A proposes a positive electrode material for a metal-air battery and a preparation method thereof. The positive electrode material of the metal-air battery comprises a metal mesh structure substrate, a photocatalytically active material layer coated on its surface, and co-catalyst nanoparticles supported on the photocatalytically active material layer. The metal-air battery has the advantages of good stability, high battery efficiency, and low charge overpotential. However, this patent application still faces the problem that the composition and ratio of the photocatalytic active materials need to be further optimized.

[0004] To address the limited rate performance and cycle life of existing metal-air batteries, the catalytic activity and stability of cathode materials are insufficient. Current catalysts, often containing precious or toxic transition metals, are not only costly but also pose environmental and safety risks, making them difficult to meet the requirements of low-carbon sustainability. The oxygen reduction and evolution reactions (ORR and OER) exhibit sluggish kinetics, requiring large amounts of catalyst to maintain high reaction rates, which compromises the battery's discharge efficiency. Furthermore, the poor interfacial contact between the electrolyte and catalyst, as well as the stability of the electrode materials, negatively impact the battery's long-term performance. The development of novel catalysts with high catalytic activity, high stability, low cost, and environmental friendliness has become a research priority. In particular, materials capable of dual electrocatalysis in both the ORR and OER are needed to enhance the battery's power density and cycling stability. Optimizing electrode structure design, improving electrolyte interfacial contact, and enhancing the conductivity and stability of electrode materials are also crucial for improving the performance of metal-air batteries. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a catalyst material for metal-air batteries and a preparation method and application thereof, so as to solve the technical problem of low electrocatalytic efficiency of metal-air batteries.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention discloses a method for preparing a catalyst material for a metal-air battery, comprising: 1) dissolving polyacrylonitrile in N,N-dimethylformamide, stirring evenly, electrospinning, drying, and heat treating to obtain carbon nanofibers; 2) dissolving carbon nanofibers, cobalt chloride hexahydrate, nickel chloride hexahydrate, and sodium hydroxide in ethylene glycol to obtain a mixed solution, subjecting the solution to a hydrothermal reaction, washing, and drying to obtain a catalyst material for a metal-air battery.

[0007] Preferably, in step 1), the usage ratio of polyacrylonitrile and N,N-dimethylformamide is (40-80) g:1 L.

[0008] Preferably, in step 1), the electrospinning conditions include: a spinning voltage of 15-18 kV, a syringe injection rate of 0.8-1.2 mL·h -1 , the receiving distance of the roller to collect the electrospun fibers is 10~20cm.

[0009] Preferably, in step 1), the drying temperature is 200-300° C., and the drying time is 10-20 hours.

[0010] Preferably, in step 1), the heat treatment conditions include: heating to 800-1200°C at a heating rate of 10-20°C / min under a nitrogen atmosphere, and keeping the temperature for 6-12 hours; the nitrogen flow rate is 20-60 mL / min.

[0011] Preferably, in step 2), the mass ratio of cobalt chloride hexahydrate to nickel chloride hexahydrate is 1:1-1:2, the mass ratio of cobalt chloride hexahydrate to sodium hydroxide is 1:3-1:5, the usage ratio of cobalt chloride hexahydrate to ethylene glycol is (2-4) g:1 L, and the mass ratio of carbon nanofiber to cobalt chloride hexahydrate is 1:1-2:1.

[0012] Preferably, in step 2), the hydrothermal reaction temperature is 150-200°C, and the time is 6-12 hours; ethanol is used for washing, and the drying temperature is 50-80°C.

[0013] The present invention also discloses a catalyst material for a metal-air battery, which is prepared using the above-mentioned method for preparing the catalyst material for a metal-air battery; the catalyst material for the metal-air battery includes: fibrous polyacrylonitrile and a cobalt-nickel alloy supported on the polyacrylonitrile.

[0014] Preferably, the mass ratio of the cobalt-nickel alloy to the polyacrylonitrile fiber is (30%-50%): (50%-70%).

[0015] The present invention also discloses the use of the catalyst material for metal-air batteries prepared by the above-mentioned preparation method of the catalyst material for metal-air batteries in metal-air batteries.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for preparing a catalyst material for metal-air batteries. Polyacrylonitrile is fabricated into a fibrous structure, forming a high-specific-surface-area three-dimensional network. This provides abundant support sites for cobalt-nickel alloy loading, and the fibrous structure facilitates electrolyte penetration and ion transport. The polyacrylonitrile fibers are then converted into carbon nanofibers through high-temperature carbonization, improving the material's conductivity and forming a continuous conductive network that promotes electron transport. A hydrothermal reaction allows the cobalt-nickel alloy to be uniformly loaded onto the surface of the carbon nanofibers, ensuring the dispersion of catalytically active sites, preventing agglomeration, and improving catalytic efficiency. Combining the structural control of electrospinning with the uniform loading achieved by a solvothermal method, the preparation process is simple and enables the cost-effective production of high-performance metal-air battery catalyst materials, making them suitable for industrial production. The raw materials and solvents used throughout the preparation process are relatively environmentally friendly, and minimal waste is generated during the preparation process. This helps reduce environmental pollution and aligns with the development trend of green chemistry. The resulting catalyst material for metal-air batteries can be applied in the metal-air battery field, leveraging the excellent catalytic properties of cobalt-nickel alloy to enhance electrocatalytic efficacy while utilizing the cross-linked structure provided by polyacrylonitrile to improve conductivity.

[0017] Furthermore, the ratio of polyacrylonitrile to N,N-dimethylformamide is (40-80) g:1 L, ensuring an appropriate electrospinning solution viscosity to avoid fiber breakage due to low concentration or spinning difficulties due to high concentration, thereby ensuring the continuity and uniformity of the electrospun fibers. The appropriate solution concentration forms nanofibers with uniform diameters, which, after carbonization, yield carbon nanofibers with moderate porosity, providing an ideal support structure for cobalt-nickel alloy loading.

[0018] Furthermore, the spinning voltage is 15-18 kV, which can balance the electric field force and the surface tension of the solution to form fibers with uniform diameters, avoiding excessive high voltage causing fiber splashing or excessive low voltage causing fiber coarseness. The syringe injection rate is 0.8-1.2 mL·h -1 The roller collects electrospun fibers at a distance of 10-20 cm to control the degree of solvent volatilization in the air. A close distance can easily lead to solvent residue, while a long distance can easily cause fiber breakage. This range produces electrospun fibers with a smooth surface and dense structure.

[0019] Furthermore, the drying temperature is 200-300°C for 10-20 hours. High-temperature drying completely removes the N,N-dimethylformamide solvent from the electrospun fibers, preventing residual solvent from affecting the carbonization reaction during subsequent heat treatment. Controlling the drying temperature and time prevents fiber shrinkage or deformation due to rapid heating, ensuring that the fibers retain their original morphology before carbonization, laying the foundation for the formation of uniform carbon nanofibers after carbonization.

[0020] Furthermore, a nitrogen atmosphere prevents oxidation of the polyacrylonitrile fibers at high temperatures, ensuring a smooth carbonization process and the formation of high-purity carbon nanofibers. A heating rate of 10-20°C / min prevents fiber cracking due to thermal stress and ensures structural integrity. The degree of graphitization of the carbon nanofibers can be adjusted by heating to 800-1200°C and holding for 6-12 hours. A nitrogen flow rate of 20-60 mL / min promptly removes gases generated during carbonization, preventing pore blockage and maintaining the porous structure of the fibers.

[0021] Furthermore, the mass ratio of cobalt chloride hexahydrate and nickel chloride hexahydrate is 1:1~1:2, which can optimize the catalytic activity of the alloy, and the synergistic effect of the two is better than the catalytic effect of a single metal; the mass ratio of cobalt chloride hexahydrate to sodium hydroxide is 1:3~1:5, which can provide sufficient alkaline conditions to promote the hydrolysis of metal ions to generate hydroxide precursors, and then reduce them to alloy particles under solvent thermal conditions, avoiding incomplete precipitation of metal ions; the dosage ratio of cobalt chloride hexahydrate to ethylene glycol is (2~4) g:1L. Ethylene glycol as a solvent can dissolve metal salts and provide a reducing environment to ensure the appropriate solution concentration and avoid excessive concentration leading to agglomeration of alloy particles; the mass ratio of carbon nanofibers to cobalt chloride hexahydrate is 1:1~2:1; it can balance the loading amount of the carrier and the active substance, ensuring sufficient catalytic sites and avoiding excessive loading leading to a decrease in conductivity.

[0022] Furthermore, the hydrothermal reaction temperature is 150-200°C, which can promote the reduction reaction of metal ions in ethylene glycol, forming small and uniform cobalt-nickel alloy particles and preventing particle growth and agglomeration at high temperatures. Low temperatures will result in incomplete reaction and insufficient active sites. The reaction time is 6-12 hours, ensuring that the alloy particles are fully deposited on the surface of the carbon nanofibers, forming a tightly bound interface, improving catalytic stability, and avoiding insufficient loading due to too short a time or particle agglomeration due to too long a time. Ethanol washing is used to remove residual salts and unreacted metal precursors from the reaction, preventing impurities from affecting the electrochemical performance of the catalyst. The drying temperature is 50-80°C. Low-temperature drying prevents alloy particles from oxidizing due to high temperatures, while also preventing shrinkage of the carbon nanofiber structure, maintaining the material's porosity and specific surface area, and ensuring the accessibility of catalytic active sites.

[0023] The present invention also discloses a catalyst material for a metal-air battery, produced using the aforementioned method for preparing a catalyst material for a metal-air battery. The carbon nanofibers formed by carbonizing fibrous polyacrylonitrile provide a three-dimensional conductive network, while a cobalt-nickel alloy is uniformly loaded on the fiber surface, forming an integrated "active site-conductive channel" structure that promotes electron transport and reactant diffusion. The high catalytic activity of the cobalt-nickel alloy combined with the conductivity of the carbon nanofibers improves the battery's charge-discharge efficiency and cycle stability, while reducing overpotential.

[0024] Furthermore, 30% to 50% cobalt-nickel alloy provides sufficient catalytic active sites, while 50% to 70% carbon nanofibers ensure a continuous conductive path, avoiding the reduced conductivity caused by too high an alloy content or the insufficient catalytic sites caused by too low a content. The appropriate mass ratio reduces the agglomeration and shedding of alloy particles during the reaction, while the support provided by the carbon nanofibers maintains the stability of the catalyst structure, extending the battery's lifespan.

[0025] The present invention also discloses the application of the catalyst material for metal-air batteries prepared by the above-mentioned method for preparing the catalyst material for metal-air batteries in metal-air batteries. Performance synergy is achieved through the integrated structure of "active site-conductive channel" constructed by cobalt-nickel alloy and carbon nanofibers; cobalt-nickel alloy provides abundant and efficient catalytic active sites, significantly improving electrocatalytic efficiency and reducing overpotential; the three-dimensional continuous conductive network formed by carbon nanofibers accelerates electron transfer and electrolyte penetration, and synergistically optimizes battery charge and discharge efficiency and cycle stability. Its preparation process combines structural control precision with cost advantages, and the raw materials are environmentally friendly and have little waste, which is adapted to the needs of industrial production, providing key material support for the high performance and green large-scale application of metal-air batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart of a method for preparing a catalyst material for a metal-air battery disclosed in the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] In the present invention, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0029] In the present invention, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0030] In the present invention, unless otherwise specified, percentages (%) or parts refer to percentages by weight or parts by weight relative to the composition.

[0031] In the present invention, unless otherwise specified, the components involved or their preferred components can be combined with each other to form a new technical solution.

[0032] In this disclosure, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "6-22" indicates that all real numbers between "6-22" are listed herein, and "6-22" is merely an abbreviation for these numerical combinations.

[0033] The "range" disclosed in the present invention is in the form of lower limit and upper limit, which can be one or more lower limits, and one or more upper limits respectively.

[0034] In the present invention, the term "and / or" used herein refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0035] In the present invention, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the order. Preferably, the reaction method herein is carried out sequentially.

[0036] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention.

[0037] The invention discloses a catalyst material for a metal-air battery, comprising two parts: polyacrylonitrile and a cobalt-nickel alloy. The polyacrylonitrile is in a fibrous shape, and the cobalt-nickel alloy is loaded on the polyacrylonitrile fiber.

[0038] The mass ratio of cobalt-nickel alloy to polyacrylonitrile fiber is (30%~50%): (50%~70%).

[0039] The present invention discloses a catalyst material for a metal-air battery, comprising a cobalt-nickel alloy and polyacrylonitrile fibers. The polyacrylonitrile is in fibrous form, and the cobalt-nickel alloy is supported on the polyacrylonitrile. Combining the excellent catalytic properties of the cobalt-nickel alloy with the cross-linked structure of the polyacrylonitrile can significantly improve the catalytic efficiency and conductivity of the metal-air battery. The cobalt-nickel alloy, as the active component of the catalyst, can promote the electrochemical reaction in the metal-air battery. The cobalt-nickel alloy supported on the polyacrylonitrile fibers gives the catalyst material a larger specific surface area, thereby providing more catalytically active sites and helping to form a stable catalytic structure. This gives the catalyst material a unique three-dimensional structure that facilitates electrolyte penetration and ion transport, thereby improving the battery's reaction rate and efficiency. The polyacrylonitrile fibers themselves have a certain degree of conductivity, and as a support structure for the catalyst material, they can form a continuous conductive network. The combination of the cobalt-nickel alloy and the polyacrylonitrile fibers improves the overall conductivity of the catalyst material, facilitating electron transport within the catalyst material, thereby enhancing the stability and durability of the catalyst, further improving catalytic efficiency, increasing conductivity, and reducing costs.

[0040] Furthermore, by optimizing the mass ratio of cobalt-nickel alloy to polyacrylonitrile, the catalytic performance and conductivity can be further balanced to achieve the best catalytic effect. This helps to ensure sufficient catalytic sites while also providing a good electron transport path.

[0041] The present invention also discloses a method for preparing a catalyst material for a metal-air battery, comprising the following steps: Dissolve polyacrylonitrile in N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospinning the electrospinning solution; The electrospun composite material was dried in a drying oven; The dried sample was heat-treated in a muffle furnace to obtain carbon nanofibers; dissolving carbon nanofibers, cobalt chloride hexahydrate, nickel chloride hexahydrate, and sodium hydroxide in ethylene glycol to obtain a mixed solution; The mixed solution was transferred to an autoclave and placed in a drying oven; After the reaction is completed, the solution is washed and dried to obtain the final composite catalytic material.

[0042] As a further improvement of the present invention, the ratio of polyacrylonitrile to N,N-dimethylformamide is (40-80) g:1 L.

[0043] As a further improvement of the present invention, the spinning voltage is 15-18 kV, and the syringe injection rate is 0.8-1.2 mL·h -1 , the receiving distance of the roller to collect the electrospun fibers is 10~20cm.

[0044] As a further improvement of the present invention, the drying temperature is 200-300° C., and the drying time is 10-20 hours.

[0045] As a further improvement of the present invention, the heat treatment conditions are: in a nitrogen atmosphere, heating to 800-1200°C at a heating rate of 10-20°C / min, and keeping warm for 6-12 hours; the nitrogen flow rate is 20-60 mL / min.

[0046] As a further improvement of the present invention, the mass ratio of cobalt chloride hexahydrate to nickel chloride hexahydrate is 1:1-1:2, the mass ratio of cobalt chloride hexahydrate to sodium hydroxide is 1:3-1:5, the ratio of cobalt chloride hexahydrate to ethylene glycol is (2-4) g:1L, and the mass ratio of carbon nanofiber to cobalt chloride hexahydrate is 1:1-2:1.

[0047] As a further improvement of the present invention, the drying oven temperature is 150-200° C., and the holding time is 6-12 hours.

[0048] As a further improvement of the present invention, the washing condition is ethanol washing, and the drying condition is drying at 50-80°C.

[0049] The method for preparing the catalyst material for metal-air batteries disclosed in the present invention is simple and feasible, and can prepare high-performance metal-air battery catalyst materials at low cost. The raw materials and solvents used in the entire preparation process are relatively environmentally friendly, and less waste is generated during the preparation process. This is conducive to reducing environmental pollution and is in line with the development trend of green chemistry. The prepared catalyst material for metal-air batteries can be applied in the field of metal-air batteries; the excellent catalytic properties of cobalt-nickel alloy are used to improve the electrocatalytic effect, and the cross-linked structure provided by polyacrylonitrile is used to improve the conductivity; by adopting the solvent thermal method and electrospinning method, by changing the content of polyacrylonitrile and cobalt-nickel alloy, better catalytic performance is obtained; the preparation method is simple, the production cost is low, the subsequent treatment is simple, and no complicated synthesis equipment is required.

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] Example 1 A method for preparing a catalyst material for a metal-air battery comprises the following steps: Step 1: Dissolve 0.2 g of polyacrylonitrile in 5 mL of N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospin the electrospinning solution at a spinning voltage of 15 kV and a syringe injection rate of 0.8 mL·h. -1 , the receiving distance of the drum to collect the electrospun fibers is 10 cm; Step 2: The electrospun composite material was dried in a drying oven at 200°C for 20 h; the dried sample was heated to 800°C in a muffle furnace at a heating rate of 10°C / min and kept at that temperature for 12 h with a nitrogen flow rate of 20 mL / min to obtain carbon nanofibers; Step 3: Dissolve 0.2 g of carbon nanofibers, 0.2 g of cobalt chloride hexahydrate, 0.2 g of nickel chloride hexahydrate, and 0.6 g of sodium hydroxide in 50 mL of ethylene glycol to obtain a mixed solution; transfer the mixed solution to a high-pressure reactor and place it in a drying oven, and keep it warm at 150°C for 12 hours; after the reaction is completed, wash the solution with ethanol and dry it at 50°C to obtain the final composite catalytic material.

[0052] Among them, the mass of cobalt-nickel alloy is 33% of the catalytic material used for metal-air batteries, and the mass of polyacrylonitrile fiber is 67% of the catalytic material used for metal-air batteries.

[0053] Figure 1 This is a flow chart of the method for preparing a catalyst material for a metal-air battery disclosed in the present invention. As can be seen from the figure, the method for preparing the catalyst material for a metal-air battery comprises: dissolving polyacrylonitrile in N,N-dimethylformamide, stirring uniformly, electrospinning, drying, and heat treating to obtain carbon nanofibers; dissolving the carbon nanofibers with cobalt chloride hexahydrate, nickel chloride hexahydrate, and sodium hydroxide in ethylene glycol to obtain a mixed solution, subjecting it to a hydrothermal reaction, washing, and drying to obtain the catalyst material for a metal-air battery. A cobalt-nickel alloy serves as the active moiety, promoting the electrochemical reaction in the metal-air battery. The cobalt-nickel alloy is supported on the polyacrylonitrile to form a cross-linked structure, which increases the catalyst's specific surface area and provides more catalytically active sites. The unique and stable three-dimensional catalytic structure facilitates electrolyte penetration and ion transport, thereby improving the reaction rate, catalytic efficiency, and conductivity of the metal-air battery.

[0054] Example 2 A method for preparing a catalyst material for a metal-air battery comprises the following steps: Step 1: Dissolve 0.4 g of polyacrylonitrile in 5 mL of N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospin the electrospinning solution at a spinning voltage of 18 kV and a syringe injection rate of 1.2 mL·h. -1 , the receiving distance of the drum to collect the electrospun fibers is 20 cm; Step 2: The electrospun composite material was dried in a drying oven at 300°C for 10 h; the dried sample was heated to 1200°C in a muffle furnace at a heating rate of 20°C / min and kept at that temperature for 6 h with a nitrogen flow rate of 60 mL / min to obtain carbon nanofibers; Step 3: Dissolve 0.5 g of carbon nanofibers, 0.2 g of cobalt chloride hexahydrate, 0.4 g of nickel chloride hexahydrate, and 1.0 g of sodium hydroxide in 100 mL of ethylene glycol to obtain a mixed solution; transfer the mixed solution to a high-pressure reactor and place it in a drying oven at 200°C for 6 hours; after the reaction is completed, the solution is washed with ethanol and dried at 80°C to obtain the final composite catalytic material.

[0055] Among them, the mass of cobalt-nickel alloy is 45% of the catalytic material used for metal-air batteries, and the mass of polyacrylonitrile fiber is 55% of the catalytic material used for metal-air batteries.

[0056] Example 3 A method for preparing a catalyst material for a metal-air battery comprises the following steps: Step 1: Dissolve 0.25 g of polyacrylonitrile in 5 mL of N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospin the electrospinning solution at a spinning voltage of 16 kV and a syringe injection rate of 1.0 mL·h. -1 , the receiving distance of the drum to collect the electrospun fibers is 15 cm; Step 2: The electrospun composite material was dried in a drying oven at 250°C for 15 h; the dried sample was heated to 1000°C in a muffle furnace at a heating rate of 15°C / min and kept at that temperature for 8 h with a nitrogen flow rate of 30 mL / min to obtain carbon nanofibers; Step 3: Dissolve 0.5 g of carbon nanofibers, 0.2 g of cobalt chloride hexahydrate, 0.3 g of nickel chloride hexahydrate, and 0.8 g of sodium hydroxide in 60 mL of ethylene glycol to obtain a mixed solution; transfer the mixed solution to a high-pressure reactor and place it in a drying oven, and keep it warm at 180°C for 10 hours; after the reaction is completed, wash the solution with ethanol and dry it at 70°C to obtain the final composite catalytic material.

[0057] The mass of the cobalt-nickel alloy is 50% of the catalytic material used for the metal-air battery, and the mass of the polyacrylonitrile fiber is 50% of the catalytic material used for the metal-air battery.

[0058] Example 4 A method for preparing a catalyst material for a metal-air battery comprises the following steps: Step 1: Dissolve 0.3 g of polyacrylonitrile in 5 mL of N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospin the electrospinning solution at a spinning voltage of 17 kV and a syringe injection rate of 1.0 mL·h. -1 , the receiving distance of the drum to collect the electrospun fibers is 15 cm; Step 2: The electrospun composite material was dried in a drying oven at 280°C for 12 h; the dried sample was heated to 900°C in a muffle furnace at a heating rate of 15°C / min and kept at this temperature for 10 h with a nitrogen flow rate of 40 mL / min to obtain carbon nanofibers; Step 3: Dissolve 0.34 g of carbon nanofibers, 0.3 g of cobalt chloride hexahydrate, 0.5 g of nickel chloride hexahydrate, and 1.0 g of sodium hydroxide in 100 mL of ethylene glycol to obtain a mixed solution; transfer the mixed solution to a high-pressure reactor and place it in a drying oven, and keep it warm at 160°C for 10 hours; after the reaction is completed, wash the solution with ethanol and dry it at 60°C to obtain the final composite catalytic material.

[0059] Among them, the mass of cobalt-nickel alloy is 30% of the catalytic material used for metal-air batteries, and the mass of polyacrylonitrile fiber is 70% of the catalytic material used for metal-air batteries.

[0060] Example 5 A method for preparing a catalyst material for a metal-air battery comprises the following steps: Step 1: Dissolve 0.35 g of polyacrylonitrile in 5 mL of N,N-dimethylformamide and stir evenly to obtain an electrospinning solution; electrospin the electrospinning solution at a spinning voltage of 17 kV and a syringe injection rate of 1.0 mL·h. -1 , the receiving distance of the drum to collect the electrospun fibers is 15 cm; Step 2: The electrospun composite material was dried in a drying oven at 220°C for 18 h; the dried sample was heated to 1000°C in a muffle furnace at a heating rate of 20°C / min and kept at this temperature for 10 h with a nitrogen flow rate of 50 mL / min to obtain carbon nanofibers; Step 3: Dissolve 0.6 g of carbon nanofibers, 0.3 g of cobalt chloride hexahydrate, 0.3 g of nickel chloride hexahydrate, and 0.9 g of sodium hydroxide in 75 mL of ethylene glycol to obtain a mixed solution; transfer the mixed solution to a high-pressure reactor and place it in a drying oven, and keep it warm at 170°C for 9 hours; after the reaction is completed, wash the solution with ethanol and dry it at 60°C to obtain the final composite catalytic material.

[0061] The mass of the cobalt-nickel alloy is 50% of the catalytic material used for the metal-air battery, and the mass of the polyacrylonitrile fiber is 50% of the catalytic material used for the metal-air battery.

[0062] In summary, the present invention discloses a catalyst material for a metal-air battery, a preparation method thereof, and an application thereof. The catalyst material for a metal-air battery comprises polyacrylonitrile and a cobalt-nickel alloy; wherein the cobalt-nickel alloy is loaded on a polyacrylonitrile fiber. The preparation method comprises: preparing polyacrylonitrile into a composite fiber by an electrospinning method, obtaining carbon nanofibers after heat treatment, and synthesizing a composite catalytic material from the carbon nanofibers and the cobalt-nickel alloy by a solvent thermal method. Polyacrylonitrile fibers are prepared by electrospinning, and the polyacrylonitrile fibers are treated with cobalt and nickel by a solvent thermal method to obtain a composite catalytic material. The catalyst material for a metal-air battery prepared by the present invention has a stable structure, a simple preparation process, and excellent catalytic performance. Moreover, the preparation method is simple, low-cost, and environmentally friendly, making it suitable for industrial large-scale production.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a catalyst material for a metal-air battery, characterized in that: include: 1) dissolving polyacrylonitrile in N,N-dimethylformamide, stirring evenly, electrospinning, drying, and heat treating to obtain carbon nanofibers; 2) dissolving carbon nanofibers, cobalt chloride hexahydrate, nickel chloride hexahydrate, and sodium hydroxide in ethylene glycol to obtain a mixed solution, subjecting the solution to a hydrothermal reaction, washing, and drying to obtain a catalyst material for a metal-air battery.

2. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 1), the usage ratio of polyacrylonitrile and N,N-dimethylformamide is (40-80) g:1 L.

3. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 1), the electrospinning conditions include: a spinning voltage of 15-18 kV, a syringe injection rate of 0.8-1.2 mL·h -1 , the receiving distance of the roller to collect the electrospun fibers is 10~20cm.

4. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 1), the drying temperature is 200-300° C., and the drying time is 10-20 hours.

5. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 1), the heat treatment conditions include: heating to 800-1200°C at a heating rate of 10-20°C / min under a nitrogen atmosphere, and keeping the temperature for 6-12 hours; the nitrogen flow rate is 20-60 mL / min.

6. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 2), the mass ratio of cobalt chloride hexahydrate to nickel chloride hexahydrate is 1:1-1:2, the mass ratio of cobalt chloride hexahydrate to sodium hydroxide is 1:3-1:5, the amount ratio of cobalt chloride hexahydrate to ethylene glycol is (2-4) g:1 L, and the mass ratio of carbon nanofiber to cobalt chloride hexahydrate is 1:1-2:

1.

7. The method for preparing a catalyst material for a metal-air battery according to claim 1, wherein: In step 2), the hydrothermal reaction temperature is 150-200° C., and the time is 6-12 hours; ethanol is used for washing, and the drying temperature is 50-80° C.

8. A catalyst material for a metal-air battery, characterized in that The catalyst material for a metal-air battery is prepared by the method for preparing the catalyst material for a metal-air battery according to any one of claims 1 to 7; the catalyst material for a metal-air battery comprises: fibrous polyacrylonitrile and a cobalt-nickel alloy supported on the polyacrylonitrile.

9. The catalyst material for a metal-air battery according to claim 8, characterized in that The mass ratio of the cobalt-nickel alloy to the polyacrylonitrile fiber is (30%-50%): (50%-70%).

10. Use of the catalyst material for a metal-air battery prepared by the method for preparing the catalyst material for a metal-air battery according to any one of claims 1 to 7 in a metal-air battery.

Images