Preparation method and device of composite negative electrode of flow battery and electronic equipment

Abstract

The invention provides a preparation method and device of a composite negative electrode of a flow battery and electronic equipment. Based on the method, molybdenum powder and a carbon-based material are subjected to first chemical modification operation to form molybdenum nitride, nitrogen doping is formed on the surface of the carbon-based material, and a composite catalyst material is obtained; mixing the composite catalyst material with a matched adhesive and a solvent to obtain negative electrode slurry; coating the surface of a carbon-based negative electrode with the negative electrode slurry to obtain an initial negative electrode; and finally, performing second chemical modification operation on the initial negative electrode to form a molybdenum nitride layer modified by molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and forming oxygen doping on the body of the initial negative electrode to obtain a target negative electrode meeting the requirement. Therefore, through multiple chemical modification operations, the target negative electrode with relatively high conductivity, relatively good hydrophilicity and relatively large specific surface area can be prepared at relatively low cost.

Description

Technical Field

[0001] This specification belongs to the field of flow battery manufacturing technology, and in particular relates to the preparation method, apparatus and electronic equipment for composite negative electrodes of flow batteries. Background Technology

[0002] Flow batteries are a type of energy storage system with high flexibility and scalability. Because they can convert the chemical energy in the electrolyte into electrical energy, they are widely used in renewable energy storage, grid peak shaving and other fields.

[0003] The negative electrodes of flow batteries prepared by existing methods often have poor performance, specifically low conductivity, poor hydrophilicity, and small specific surface area, which in turn affect the electrochemical performance and cycle stability of the flow battery.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This specification provides a method, apparatus, and electronic device for preparing a composite negative electrode for a flow battery, which can prepare a target negative electrode with high conductivity, good hydrophilicity, and large specific surface area at a relatively low cost.

[0006] This specification provides a method for preparing a composite negative electrode for a flow battery, including: By using molybdenum powder and carbon-based materials, a first chemical modification operation is performed to form molybdenum nitride, and nitrogen doping is formed on the surface of the carbon-based materials to obtain a composite catalyst material. The composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry; and the negative electrode slurry is coated onto the surface of a carbon-based negative electrode to obtain an initial negative electrode. A second chemical modification operation is performed on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and oxygen doping is formed in the bulk of the initial negative electrode to obtain the target negative electrode that meets the requirements.

[0007] In one embodiment, the composite catalyst material obtained by using molybdenum powder and carbon-based materials through a first chemical modification operation includes: According to preset processing rules, molybdenum powder and carbon-based materials in a first preset ratio are obtained; and the molybdenum powder and carbon-based materials are ground and mixed using a ball mill to obtain a first mixed material. The first mixture is placed in a tube furnace; Nitrogen and ammonia are introduced into the tubular furnace according to a first gas flow rate and a second gas flow rate; and the tubular furnace is heated until a first specified temperature is reached; The tubular furnace is controlled to maintain a first specified temperature for a first duration.

[0008] In one embodiment, after obtaining the composite catalyst material, the method further includes: Argon gas is introduced into the tube furnace as a protective gas; and the tube furnace is heated according to a first heating rate until a second specified temperature is reached; The tubular furnace is controlled to maintain a second specified temperature for a second duration.

[0009] In one embodiment, the carbon-based material includes at least one of the following: carbon nanotubes, graphene, and porous carbon.

[0010] In one embodiment, the use of the composite catalyst material, mixed with a matching binder and solvent, to obtain a negative electrode slurry includes: Based on the composite catalyst material, obtain a binder that meets the second preset ratio; A second mixed material is obtained by grinding and mixing the composite catalyst material and the binder; A solvent compatible with the binder is added to the second mixture; and the mixture is ground and mixed to obtain a negative electrode slurry.

[0011] In one embodiment, the carbon-based negative electrode includes at least one of the following: a negative electrode made of carbon felt, a negative electrode made of graphite felt, a negative electrode made of carbon cloth, and a negative electrode made of carbon paper.

[0012] In one embodiment, the second chemical modification operation on the initial negative electrode includes: The initial negative electrode is placed in an oxidation furnace; An oxidizing gas is introduced into the oxidation furnace; and the oxidation furnace is heated until the third specified temperature is reached; The oxidation furnace is controlled to be maintained at a third specified temperature for a third duration.

[0013] In one embodiment, after obtaining the target negative electrode that meets the requirements, the method further includes: According to the preset test rules, the electrochemical performance of the target negative electrode is tested to obtain the first test result; The target negative electrode is subjected to single-cell performance testing to obtain a second test result. Based on the first test result and the second test result, determine whether the target negative electrode meets the requirements.

[0014] This specification also provides an apparatus for preparing a composite negative electrode for a flow battery, comprising: The first chemical modification module is used to form molybdenum nitride by performing a first chemical modification operation on molybdenum powder and carbon-based materials, and to form nitrogen doping on the surface of the carbon-based materials to obtain a composite catalyst material. The processing module is used to mix the composite catalyst material with a matching binder and solvent to obtain a negative electrode slurry; and to coat the negative electrode slurry onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; The second chemical modification module is used to perform a second chemical modification operation on the initial negative electrode, so as to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and to form oxygen doping in the bulk of the initial negative electrode, so as to obtain the target negative electrode that meets the requirements.

[0015] This specification also provides an electronic device including a processor and a memory for storing processor-executable instructions, the processor performing the steps of the method for preparing the composite negative electrode of the flow battery.

[0016] This specification also provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the method for preparing the composite negative electrode of the flow battery.

[0017] Based on the preparation method, apparatus, and electronic equipment for the composite negative electrode of the flow battery provided in this specification, a first chemical modification operation is performed using molybdenum powder and carbon-based materials to form molybdenum nitride and nitrogen doping on the surface of the carbon-based materials, resulting in a composite catalyst material. Then, the composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry. This slurry is then coated onto the surface of the carbon-based negative electrode to obtain an initial negative electrode. Finally, a second chemical modification operation is performed on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the initial negative electrode, and oxygen doping is formed in the bulk of the initial negative electrode, resulting in a target negative electrode that meets the requirements. Thus, through multiple chemical modification operations, a target negative electrode with high conductivity, good hydrophilicity, and a large specific surface area can be prepared at a relatively low cost. This target negative electrode can then be used to further prepare flow batteries with high electrochemical performance and good cycle stability. Attached Figure Description

[0018] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of a method for preparing a composite negative electrode for a flow battery according to one embodiment of this specification; Figure 2 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 3 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 4 This is a schematic diagram of the structural composition of an electronic device provided in one embodiment of this specification; Figure 5 This is a schematic diagram of the structural composition of a composite negative electrode preparation apparatus for a flow battery provided in one embodiment of this specification; Figure 6 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 7 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 8 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 9 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 10 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode of a flow battery provided in the embodiments of this specification, in a scenario example. Figure 11 This is a schematic diagram of one embodiment of the method for preparing a composite negative electrode for a flow battery provided in the embodiments of this specification, in a scenario example. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0021] It should be noted that the information and data related to users involved in the embodiments of this specification are all information and data authorized by the user or fully authorized by the relevant parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of the relevant data all comply with relevant laws, regulations, and standards, and necessary confidentiality measures have been taken. They do not violate public order and good morals, and corresponding operation entry points are provided for users or relevant parties to choose to authorize or refuse.

[0022] It should also be noted that in the embodiments of this specification, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0023] See Figure 1 As shown in the embodiments of this specification, a method for preparing a composite negative electrode for a flow battery is provided. Specifically, this method may include the following: S101: Using molybdenum powder and carbon-based materials, a first chemical modification operation is performed to form molybdenum nitride, and nitrogen doping is formed on the surface of the carbon-based material to obtain a composite catalyst material; S102: Using the composite catalyst material, mix it with a matching binder and solvent to obtain a negative electrode slurry; and coat the negative electrode slurry onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; S103: Perform a second chemical modification operation on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and form oxygen doping in the bulk of the initial negative electrode to obtain the target negative electrode that meets the requirements.

[0024] Specifically, molybdenum (Mo) can be understood as a transition metal. Based on this molybdenum, transition metal compounds (e.g., ...) are generated through chemical modification. This can give the composite catalyst material good electrocatalytic activity and hydrophilicity.

[0025] The aforementioned carbon-based materials can be specifically understood as carbon materials with a large specific surface area, and can include various different types of carbon materials, such as carbon nanotubes, graphene, and porous carbon. Introducing carbon-based materials can effectively improve the dispersibility and electronic conductivity of transition metal compounds in composite catalyst materials, and increase the specific surface area of ​​the composite catalyst material. In practical implementation, the appropriate type of carbon-based material can be selected based on the specific battery application scenario.

[0026] The aforementioned adhesive is used to enable the negative electrode slurry containing composite catalyst material to be firmly coated and bonded to the surface of the carbon-based negative electrode.

[0027] Specifically, the aforementioned adhesives can include various different types, such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE). Different solvents can be used to match different adhesives. For example, when using PVDF as the adhesive, the matching solvent can be N-methylpyrrolidone; when using PTFE, the matching solvent can be deionized water.

[0028] The aforementioned carbon-based anode can be used as the basic structure for the target anode, and may specifically include at least one of the following: anode made of carbon felt, anode made of graphite felt, anode made of carbon cloth, anode made of carbon paper, etc. In specific implementation, a matching carbon-based anode can be selected according to the specific battery application scenario.

[0029] The first chemical modification operation mentioned above includes at least a nitrogen doping operation; the second chemical modification operation mentioned above includes at least an oxygen doping operation. In specific implementation, the first and second chemical modification operations can be performed sequentially using a multi-stage surface modification process.

[0030] The target negative electrode that meets the above requirements can be specifically understood as a negative electrode with high conductivity, good hydrophilicity, and large specific surface area, that is, a negative electrode whose conductivity, hydrophilicity, and specific surface area meet the preset parameter requirements.

[0031] The aforementioned target negative electrode can be used to fabricate flow batteries. These flow batteries can include, for example, all-vanadium redox flow batteries.

[0032] The aforementioned flow battery can be understood as a type of storage battery, consisting of a stack unit, electrolyte, electrolyte storage and supply unit, and management and control unit. It is a high-performance storage battery that utilizes separate positive and negative electrolytes for independent circulation, and features high capacity, wide range of applications, and long cycle life.

[0033] In specific implementation, firstly, according to the preset processing rules, molybdenum powder and carbon-based materials that meet the first preset ratio can be obtained, mixed, and then subjected to a first chemical modification operation to form molybdenum nitride (e.g., MoNx), while nitrogen doping is formed on the surface of the carbon-based material to obtain a composite catalyst material.

[0034] The aforementioned preset processing rules can include at least: configuration rules, operation rules, testing rules, and adjustment rules. Before implementation, multiple experiments can be conducted using different types of carbon-based materials to collect a large number of experimental test results. Based on these experimental test results and the type of carbon-based material, cluster learning is performed. Based on the cluster learning results, the common characteristics exhibited by the same type of carbon-based material in the process of preparing composite anodes that meet the target requirements are determined, and corresponding preset processing rules are constructed.

[0035] Specifically, the mixed molybdenum powder and carbon-based materials can be moved into a tube furnace; then a protective gas (e.g., nitrogen) can be introduced into the tube furnace. ) and nitrogen gases (e.g., ammonia) ), and perform the first chemical modification operation.

[0036] The aforementioned composite catalyst material may include at least: molybdenum nitride, a carbon-based material, and nitrogen doping on the surface of the carbon-based material. Specifically, the molybdenum nitride is used to improve electrocatalytic activity, the carbon-based material is used to improve specific surface area and conductivity, and the nitrogen doping is used to further improve electrocatalytic activity and conductivity.

[0037] Next, the aforementioned composite catalyst material can be mixed with a matching binder and solvent to prepare a corresponding negative electrode slurry; then, the negative electrode slurry is coated onto the surface of a carbon-based negative electrode to obtain an initial negative electrode.

[0038] Then, the initial negative electrode can be moved to an oxidation furnace; in the oxidation furnace, a second chemical modification operation is performed on the initial negative electrode to form molybdenum oxide (e.g., molybdenum oxide) based on the molybdenum nitride coated on the surface of the initial negative electrode. ), to obtain a molybdenum nitride layer modified with molybdenum oxide (e.g., Meanwhile, oxygen doping is further generated on the bulk of the initial negative electrode (carbon-based negative electrode) to obtain the target negative electrode that meets the requirements.

[0039] Specifically, the initial negative electrode can be moved into the oxidation furnace; then an oxidizing gas (e.g., oxygen) can be introduced into the oxidation furnace. The second chemical modification operation is then performed.

[0040] Among them, the molybdenum oxide is used to improve the electrocatalytic activity and enhance the electrochemical performance of the electrode, and the oxygen doping is used to improve the hydrophilicity of the negative electrode.

[0041] In practice, the difference between the proportion of molybdenum powder obtained and used and the proportion of carbon-based material is greater than a preset threshold for the difference. This ensures, on the one hand, that a sufficient amount of molybdenum nitride is generated during the first chemical modification operation; on the other hand, it also ensures that during the second chemical modification operation, there is enough molybdenum in the material coated on the surface of the carbon-based negative electrode to react with the oxidizing gas and generate a sufficient amount of molybdenum oxide, while also preventing the oxidizing gas from consuming the molybdenum nitride in the material.

[0042] In specific implementation, after mixing the composite catalyst material with a matching binder and solvent to obtain a negative electrode slurry, a matching pore-forming agent (e.g., ammonium bicarbonate) can be added to the negative electrode slurry to obtain an improved negative electrode slurry. This improved negative electrode slurry is then used to replace the original negative electrode slurry and coated onto the surface of the carbon-based negative electrode to obtain the initial negative electrode. Correspondingly, after obtaining the initial negative electrode, it can undergo a thermal decomposition-based pretreatment to eliminate the pore-forming agent mixed in the surface material layer, thus forming multiple small pores in the surface material layer. In this way, during the subsequent second chemical modification operation, on the one hand, the pores allow the oxidizing gas to fully react with the molybdenum powder in the surface material layer to generate molybdenum oxide; on the other hand, the oxidizing gas can also pass through the pores to smoothly enter and contact the negative electrode body, forming the required oxygen doping in the initial negative electrode body, thereby achieving a better second chemical modification effect.

[0043] In specific implementation, when performing the second chemical modification operation, at least one of the following parameters can be specifically adjusted and controlled based on the amount of molybdenum nitride generated in the first chemical modification operation through optimization: the duration of oxidizing gas introduction, the rate of oxidizing gas introduction, the heating temperature, and the duration of heating, so that the ratio of the amount of molybdenum oxide generated to the amount of molybdenum nitride in the negative electrode surface material layer meets the preset ratio threshold. In this way, by finely balancing the relative content ratio of molybdenum oxide and molybdenum nitride on the negative electrode surface, the final target negative electrode can have a relatively better application effect.

[0044] Based on the above embodiments, through multiple chemical modification operations, a target negative electrode with high conductivity, good hydrophilicity, and large specific surface area can be prepared at a relatively low cost, meeting the requirements.

[0045] In some embodiments, see Figure 2 As shown, the composite catalyst material obtained by using molybdenum powder and carbon-based materials through a first chemical modification operation can specifically include the following: S2-1: According to the preset processing rules, obtain molybdenum powder and carbon-based materials that meet the first preset ratio; and use a ball mill to grind and mix the molybdenum powder and carbon-based materials to obtain a first mixed material; S2-2: Place the first mixture in a tube furnace; S2-3: Nitrogen and ammonia are introduced into the tubular furnace according to the first gas flow rate and the second gas flow rate; and the tubular furnace is heated until the first specified temperature is reached; S2-4: Control the tubular furnace to maintain a first specified temperature for a first duration.

[0046] Specifically, the carbon-based materials mentioned above may include at least one of the following: carbon nanotubes (CNTs), graphene, porous carbon (AC), etc. It should be noted that the carbon-based materials listed above are merely illustrative. In actual implementation, other types of carbon-based materials may be included depending on the specific circumstances and processing requirements. This specification does not limit this.

[0047] Specifically, the first specified temperature can be taken from the following temperature range [400 degrees Celsius, 600 degrees Celsius]; the first duration can be taken from the following duration range [1 hour, 3 hours]. The specific values ​​of the first specified temperature and the first duration can be determined according to the type of carbon-based material used.

[0048] Specifically, different types of carbon-based materials differ in their specific properties. For example, porous carbon has a specific surface area of ​​1800 m² / g, graphene has a specific surface area of ​​1500 m² / g, and carbon nanotubes have a specific surface area of ​​1200 m² / g, etc.

[0049] In practice, based on the preset processing rules and the specific battery application scenario, the battery-related demand information is determined; and based on this demand information, a matching carbon-based material is selected from various types of carbon-based materials; based on the type of carbon-based material determined, the configuration rules in the preset processing rules are queried to determine the matching first preset ratio.

[0050] Specifically, for example, when the requirement information is determined to be a high specific surface area based on the battery application scenario, activated carbon is selected as the carbon-based material. Furthermore, the recommended ratio of porous carbon to molybdenum powder, 2:1, can be determined by querying the configuration rules in the preset processing rules as the first preset ratio. Then, the corresponding amount of carbon-based material and molybdenum powder can be obtained according to the above first preset ratio for grinding and mixing.

[0051] When the battery application scenario determines that a medium specific surface area is required, graphene is chosen as the carbon-based material. Furthermore, by querying the configuration rules in the preset processing rules, a recommended ratio of 1:1 between graphene and molybdenum powder can be determined as the first preset ratio. Then, the corresponding amount of carbon-based material and molybdenum powder can be obtained according to the above first preset ratio for grinding and mixing.

[0052] When the battery application scenario determines that a low specific surface area is required, carbon nanotubes are selected as the carbon-based material. Furthermore, by querying the configuration rules in the preset processing rules, a recommended ratio of 1:1 between carbon nanotubes and molybdenum powder can be determined as the first preset ratio. Then, the corresponding amount of carbon-based material and molybdenum powder can be obtained according to the above first preset ratio for grinding and mixing.

[0053] In practice, nitrogen can be introduced into the tubular furnace at the first gas flow rate as a protective gas; at the same time, ammonia can be introduced into the tubular furnace at the second gas flow rate as a nitriding gas.

[0054] Specifically, based on the type of carbon-based material used, the operating rules in the preset processing rules can be queried to determine the matching first gas flow rate, second gas flow rate, first specified temperature, and first duration; then, nitrogen and ammonia are introduced into the tubular furnace according to the first and second gas flow rates; and the tubular furnace is heated until the first specified temperature is reached; then, the tubular furnace is controlled to maintain the first specified temperature for a first duration to achieve the first chemical modification operation.

[0055] For example, when the carbon-based material used is carbon nanotubes, the determined first gas flow rate and second gas flow rate are 200 sccm and 50 sccm, respectively, the first specified temperature is 500 degrees Celsius, and the first specified duration is 2 hours. Correspondingly, through the first chemical modification operation, in addition to generating molybdenum nitride, nitrogen-doped carbon nanotubes (N-CNTs) will also be formed on the surface of the carbon-based material.

[0056] For example, when the carbon-based material used is graphene, the determined first gas flow rate and second gas flow rate are 150 sccm and 100 sccm, respectively, the first specified temperature is 450 degrees Celsius, and the first specified duration is 1 hour. Correspondingly, through the first chemical modification operation, in addition to generating molybdenum nitride, nitrogen-doped graphene (N-Gr) will also be formed on the surface of the carbon-based material.

[0057] For example, when the carbon-based material used is porous carbon, the determined first gas flow rate and second gas flow rate are 200 sccm and 50 sccm, respectively, the first specified temperature is 550 degrees Celsius, and the first specified duration is 3 hours. Correspondingly, through the first chemical modification operation, in addition to generating molybdenum nitride, nitrogen-doped porous carbon (N-AC) will also be formed on the surface of the carbon-based material.

[0058] By distinguishing different types of carbon-based materials and using differentiated parameters for matching operations, the specific physical properties of the carbon-based materials used can be fully considered. This allows for a more thorough and efficient first chemical modification operation, resulting in a composite catalyst material with enhanced effects.

[0059] Thus, during the reaction of ammonia and molybdenum powder to generate molybdenum nitride (MoNx), nitrogen doping can occur simultaneously on the surface of carbon-based materials, forming nitrogen-doped carbon materials. This results in composite catalyst materials with relatively stronger surface activity and conductivity after chemical modification.

[0060] In some embodiments, after obtaining the composite catalyst material, it can be allowed to cool naturally to room temperature to obtain a surface-reinforced composite catalyst material (e.g., MoNx / N-CNT, MoNx / N-Gr, or MoNx / N-AC, etc.).

[0061] In some embodiments, after obtaining the composite catalyst material, the method may further include the following: S1: Argon gas (e.g., Ar) is introduced into the tube furnace as a protective gas; and the tube furnace is heated according to a first heating rate until a second specified temperature is reached; S2: Control the tubular furnace to maintain a second specified temperature for a second duration.

[0062] In specific implementation, according to the preset processing rules, the following can be determined: the first heating rate is 10 degrees Celsius / min, the second specified temperature can be greater than or equal to 700 degrees Celsius and less than or equal to 800 degrees Celsius, and the second duration can be greater than or equal to 2 hours and less than or equal to 3 hours.

[0063] Based on the above embodiments, by subjecting the composite catalyst material to high-temperature heat treatment, the conductivity and structural stability of the composite catalyst material can be further enhanced, the internal stress of the material can be eliminated, and its mechanical strength and electrochemical performance can be improved, resulting in a composite catalyst material with relatively better performance.

[0064] In some embodiments, the carbon-based material may specifically include at least one of the following: carbon nanotubes, graphene, porous carbon, etc. It should be noted that the carbon-based materials listed above are merely illustrative. In specific implementations, other suitable types of carbon-based materials may be included depending on the specific circumstances and processing requirements. This specification does not limit this.

[0065] In some embodiments, the use of the composite catalyst material, mixed with a matching binder and solvent, to obtain a negative electrode slurry may include the following: S1: Obtain a binder that meets the second preset ratio according to the composite catalyst material; S2: A second mixed material is obtained by grinding and mixing the composite catalyst material and the binder; S3: Add a solvent that matches the binder to the second mixture; and grind and mix to obtain a negative electrode slurry.

[0066] In practice, a matching second preset ratio can be determined based on the type of nitrogen-doped carbon material in the composite catalyst material by querying the configuration rules in the preset processing rules. The value of the second preset ratio can be greater than or equal to 7 / 1 and less than or equal to 12 / 1.

[0067] Specifically, the adhesive may include polyvinylidene fluoride (PVDF) and / or polytetrafluoroethylene (PTFE). The solvent may be a solvent that matches the type of adhesive.

[0068] When the adhesive is polyvinylidene fluoride, the matching solvent is N-methylpyrrolidone; when the adhesive is polytetrafluoroethylene, the matching solvent is deionized water.

[0069] In practice, the composite catalyst material and binder that meet the second preset ratio can be obtained first and ground and mixed evenly to obtain the second mixed material; then a solvent that matches the binder used can be added to the second mixed material; and the mixture can be ground evenly to obtain the corresponding negative electrode slurry.

[0070] In some embodiments, the carbon-based anode may specifically include at least one of the following: a carbon felt anode, a graphite felt anode, a carbon cloth anode, a carbon paper anode, etc. Of course, in specific implementations, other types of anodes may be introduced and used as the aforementioned carbon-based anodes, depending on the specific circumstances and processing requirements. This specification does not limit this.

[0071] In practice, depending on the battery application scenario, a matching negative electrode can be selected from several types of negative electrodes and used as a carbon-based negative electrode.

[0072] In some embodiments, see Figure 3 As shown, the above-described second chemical modification operation on the initial negative electrode may include the following in its specific implementation: S3-1: Place the initial negative electrode in an oxidation furnace; S3-2: Introduce oxidizing gas into the oxidation furnace; and heat the oxidation furnace until it reaches the third specified temperature; S3-3: Control the oxidation furnace to maintain at a third specified temperature for a third duration.

[0073] The third specified temperature can be taken from the following temperature range [350 degrees Celsius, 400 degrees Celsius]; the third duration can be, for example, 1 hour. The specific values ​​of the third specified temperature and the third duration can be determined according to the type of carbon-based material used.

[0074] The aforementioned oxidizing gas can specifically be oxygen. In practice, the oxidizing gas can be introduced into the oxidation furnace according to the third gas flow rate.

[0075] In practice, the third specified temperature and the third gas flow rate can be determined first based on the type of carbon-based material used and the type of carbon-based anode used. Then, according to the third gas flow rate, oxidizing gas is introduced into the oxidation furnace and the oxidation furnace is heated until the third specified temperature is reached. The oxidation furnace is then controlled to maintain the third specified temperature for a third duration to achieve the second chemical modification operation.

[0076] For example, when the carbon-based material used is carbon nanotubes, the determined third gas flow rate is 100 sccm, the third specified temperature is 400 degrees Celsius, and the third specified duration is 1 hour. Correspondingly, through the second chemical modification operation, in addition to forming a layer of molybdenum oxide on the surface of the composite catalyst material initially coated on the negative electrode surface... Modified In addition, oxygen doping (GF-O) will simultaneously form on the bulk surface of the initial negative electrode. Ultimately, the desired negative electrode is obtained, which can be represented as follows: .

[0077] For example, when the carbon-based material used is graphene, the determined third gas flow rate is 150 sccm, the third specified temperature is 350 degrees Celsius, and the third specified duration is 1 hour. Correspondingly, through the second chemical modification operation, in addition to forming a layer of molybdenum oxide on the surface of the composite catalyst material initially coated on the negative electrode surface... Modified In addition, oxygen doping (GF-O) will simultaneously form on the bulk surface of the initial negative electrode. Ultimately, the desired negative electrode is obtained, which can be represented as follows: .

[0078] For example, when the carbon-based material used is porous carbon, the determined third gas flow rate is 100 sccm, the third specified temperature is 400 degrees Celsius, and the third specified duration is 1 hour. Correspondingly, through the second chemical modification operation, in addition to forming a layer of molybdenum oxide on the surface of the composite catalyst material initially coated on the negative electrode surface... Modified In addition, oxygen doping (GF-O) will simultaneously form on the bulk surface of the initial negative electrode. Ultimately, the desired negative electrode is obtained, which can be represented as follows: .

[0079] By distinguishing between different types of carbon-based materials and different types of carbon-based anodes, and using differentiated parameters for targeted matching operations, the specific physical properties of the carbon-based materials and carbon-based anodes can be fully considered. This allows for a more thorough and efficient implementation of the second chemical modification operation, resulting in a target anode that combines high performance and excellent cycle stability with good battery application performance.

[0080] In some embodiments, after obtaining the target negative electrode that meets the requirements, the method may further include the following: S1: According to the preset test rules, the electrochemical performance of the target negative electrode is tested to obtain the first test result; S2: Perform single-cell performance testing on the target negative electrode to obtain a second test result; S3: Based on the first test result and the second test result, detect whether the target negative electrode meets the requirements.

[0081] The first test results mentioned above may include at least: cyclic voltammetry test curves and Nyquist plots of the electrodes, and the second test results mentioned above may include at least: flow battery voltage efficiency curves under multiple test current densities, etc.

[0082] The first test result is specifically used to characterize whether the properties of the target negative electrode itself meet the requirements and are qualified from the perspective of the performance of a single negative electrode. The second test result is specifically used to characterize whether the performance of the target negative electrode in a flow battery meets the requirements and is qualified from the perspective of the coordinated operation of the negative electrode, positive electrode, and electrolyte.

[0083] In practice, the target negative electrode can be subjected to corresponding electrochemical performance tests and battery cell performance tests according to the test rules in the preset processing rules.

[0084] In practice, a matching test cathode and test electrolyte can be determined based on the battery application scenario; then, the target negative electrode can be tested using the test cathode and test electrolyte to obtain the second test result.

[0085] In practice, the matching degree can be calculated based on the first test result and the first test reference template diagram to obtain the first matching degree; it can be checked whether the first matching degree is greater than the preset matching degree threshold; when the first matching degree is greater than the preset matching degree threshold, the first test result is determined to be qualified; otherwise, the first test result is determined to be unqualified.

[0086] Similarly, the matching degree can be calculated based on the second test result and the second test reference template diagram to obtain the second matching degree; check whether the second matching degree is greater than the preset matching degree threshold; when the second matching degree is greater than the preset matching degree threshold, the second test result is determined to be qualified; otherwise, the second test result is determined to be unqualified.

[0087] Specifically, the first and second test reference template diagrams mentioned above can be determined in advance through statistical learning based on the test results of the negative electrode that meets the requirements in the experimental test results.

[0088] In practice, when at least one of the first test results and the second test results indicates that the test is unqualified, it can be determined that the target negative electrode does not meet the requirements; when both the first test result and the second test result indicate that the test is qualified, it can be determined that the target negative electrode meets the requirements.

[0089] If the target negative electrode meets the requirements, it can be used to construct a corresponding flow battery, such as a vanadium redox flow battery. This flow battery can then be used for specific energy data processing applications, such as renewable energy storage and grid peak shaving.

[0090] If it is determined that the target negative electrode does not meet the requirements, targeted remedial adjustments can be made to the target negative electrode based on the first test results and / or the second test results. This can be achieved by making relatively simple corrections to the current target negative electrode so that it meets the requirements.

[0091] In some embodiments, when it is determined that the target negative electrode does not meet the requirements, the method may further include the following: S1: Based on the results of the first and second tests, determine the cause of the abnormality of the target negative electrode; S2: Based on the cause of the abnormality of the target negative electrode, query the preset remedial solution library to determine the target remedial solution for the target negative electrode; S3: According to the target remedial plan, perform corresponding remedial adjustment operations on the target negative electrode to obtain a target negative electrode that meets the requirements.

[0092] The above-mentioned determination of the abnormal cause of the target negative electrode based on the first test result and the second test result may include: according to a specified rule, sequentially splicing the relevant images in the first test result and the second test result to obtain the corresponding target image sequence; then using a preset abnormal cause classification model to process the target image sequence to obtain the corresponding target classification result; and determining the abnormal cause of the target negative electrode based on the target classification result.

[0093] Specifically, the aforementioned pre-defined abnormal cause classification model can be a neural network model trained on a graph neural network that can determine and classify the negative abnormal causes indicated by the image by processing image sequences, analyzing and based on the temporal evolution trend of key features in the image.

[0094] The aforementioned pre-defined remedial solution library may specifically include multiple pre-defined remedial solutions, each corresponding to at least one cause of an anomaly. Before implementation, a large number of remedial operation records can be collected; then, the remedial operation records are clustered based on the cause of the anomaly to obtain the corresponding clustering results; based on the clustering results, for each cause of anomaly, common operational features corresponding to that cause are extracted and combined to obtain pre-defined remedial solutions; multiple pre-defined remedial solutions are combined, and a mapping relationship between the pre-defined remedial solutions and the causes of anomalies is established to obtain a pre-defined anomaly remedial solution library.

[0095] In practice, the target negative electrode can be adjusted according to the adjustment rules in the preset processing rules, using the first test results and the second test results, so as to obtain a target negative electrode that meets the requirements.

[0096] In some embodiments, when the target negative electrode is determined to meet the requirements, the method may further include the following: based on the second test results and combined with the requirements of the battery application scenario, the test positive electrode and / or test electrolyte used in the test are specifically adjusted and optimized to obtain a target positive electrode and a target electrolyte that are compatible with the battery application scenario and the target negative electrode; then, using the target negative electrode, target positive electrode, and target electrolyte, a flow battery with good performance suitable for the battery application scenario is prepared.

[0097] As can be seen from the above, the method for preparing the composite negative electrode of the flow battery provided in the embodiments of this specification first uses molybdenum powder and carbon-based materials to perform a first chemical modification operation to form molybdenum nitride and nitrogen doping on the surface of the carbon-based material, thus obtaining a composite catalyst material. Then, the composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry. The negative electrode slurry is then coated onto the surface of the carbon-based negative electrode to obtain an initial negative electrode. Finally, a second chemical modification operation is performed on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the initial negative electrode, and oxygen doping is formed in the bulk of the initial negative electrode, thus obtaining a target negative electrode that meets the requirements. Therefore, through multiple chemical modification operations, a target negative electrode with high conductivity, good hydrophilicity, and large specific surface area can be prepared at a relatively low cost. This target negative electrode can then be used to further prepare a flow battery with high electrochemical performance and good cycle stability.

[0098] This specification provides an electronic device through its embodiments. (See attached document.) Figure 4 As shown. The electronic device includes a network communication port 401, a processor 402, and a memory 403. These structures are connected by internal cables so that they can perform specific data interaction.

[0099] Specifically, the network communication port 401 can be used to obtain preparation instructions.

[0100] The processor 402 can specifically be used to respond to preparation instructions, using molybdenum powder and carbon-based materials, to perform a first chemical modification operation to form molybdenum nitride, and to form nitrogen doping on the surface of the carbon-based material to obtain a composite catalyst material; using the composite catalyst material, mixing it with a matching binder and solvent to obtain a negative electrode slurry; and coating the negative electrode slurry onto the surface of the carbon-based negative electrode to obtain an initial negative electrode; and performing a second chemical modification operation on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the initial negative electrode, and to form oxygen doping in the bulk of the initial negative electrode to obtain a target negative electrode that meets the requirements.

[0101] The memory 403 can be used to store the corresponding instruction program and related intermediate data.

[0102] Based on the above method, the relevant structural performance of electronic devices can be effectively utilized to improve the data processing speed of electronic devices and efficiently realize the controlled processing of the preparation of composite negative electrodes for flow batteries.

[0103] In this embodiment, the network communication port 401 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0104] In this embodiment, the processor 402 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0105] In this embodiment, the memory 403 may include multiple layers. In a digital system, anything that can store binary data can be a memory. In an integrated circuit, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc. In a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0106] This specification also provides a computer-readable storage medium for a method of preparing a composite negative electrode based on the above-described flow battery. The computer-readable storage medium stores computer program instructions that, when executed, implement the following: using molybdenum powder and a carbon-based material, a first chemical modification operation is performed to form molybdenum nitride and nitrogen doping is formed on the surface of the carbon-based material to obtain a composite catalyst material; the composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry; the negative electrode slurry is coated onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; a second chemical modification operation is performed on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the initial negative electrode, and oxygen doping is formed in the bulk of the initial negative electrode to obtain a target negative electrode that meets the requirements.

[0107] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), Cache, Hard Disk Drive (HDD), or Memory Card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0108] In this embodiment, the specific functions and effects implemented by the program instructions stored in the computer-readable storage medium can be explained in comparison with other embodiments, and will not be repeated here.

[0109] This specification also provides a computer program product, comprising at least a computer program that, when executed by a processor, performs the following method steps: using molybdenum powder and a carbon-based material, performing a first chemical modification operation to form molybdenum nitride and nitrogen doping on the surface of the carbon-based material to obtain a composite catalyst material; using the composite catalyst material, mixing it with a matching binder and solvent to obtain a negative electrode slurry; coating the negative electrode slurry onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; performing a second chemical modification operation on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the initial negative electrode, and forming oxygen doping in the bulk of the initial negative electrode to obtain a target negative electrode that meets the requirements.

[0110] See Figure 5 As shown in the embodiments of this specification, an apparatus for preparing a composite negative electrode for a flow battery is also provided. This apparatus may specifically include the following structural modules: The first chemical modification module 501 can be used to use molybdenum powder and carbon-based materials to perform a first chemical modification operation to form molybdenum nitride and form nitrogen doping on the surface of the carbon-based material to obtain a composite catalyst material. The processing module 502 can be specifically used to mix the composite catalyst material with a matching binder and solvent to obtain a negative electrode slurry; and to coat the negative electrode slurry onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; The second chemical modification module 503 can be used to perform a second chemical modification operation on the initial negative electrode, so as to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and to form oxygen doping in the bulk of the initial negative electrode, so as to obtain the target negative electrode that meets the requirements.

[0111] In some embodiments, when the first chemical modification module 501 is specifically implemented, molybdenum powder and carbon-based materials can be used to obtain a composite catalyst material by performing a first chemical modification operation as follows: according to a preset processing rule, molybdenum powder and carbon-based materials in a first preset ratio are obtained; the molybdenum powder and carbon-based materials are ground and mixed using a ball mill to obtain a first mixed material; the first mixed material is placed in a tube furnace; nitrogen and ammonia are introduced into the tube furnace according to a first gas flow rate and a second gas flow rate; the tube furnace is heated until a first specified temperature is reached; the tube furnace is controlled to maintain the first specified temperature for a first duration.

[0112] In some embodiments, after obtaining the composite catalyst material, the apparatus may also be used to: introduce argon gas into a tubular furnace as a protective gas; heat the tubular furnace according to a first heating rate until a second specified temperature is reached; and control the tubular furnace to maintain the second specified temperature for a second duration.

[0113] In some embodiments, the carbon-based material may specifically include at least one of the following: carbon nanotubes, graphene, porous carbon, etc.

[0114] In some embodiments, when the processing module 502 is specifically implemented, the composite catalyst material can be used in the following manner to mix with a matching binder and solvent to obtain a negative electrode slurry: according to the composite catalyst material, a binder satisfying a second preset ratio is obtained; the composite catalyst material and the binder are ground and mixed to obtain a second mixed material; a solvent matching the binder is added to the second mixed material; and grinding and mixing are performed to obtain a negative electrode slurry.

[0115] In some embodiments, the carbon-based negative electrode may specifically include at least one of the following: a negative electrode made of carbon felt, a negative electrode made of graphite felt, a negative electrode made of carbon cloth, a negative electrode made of carbon paper, etc.

[0116] In some embodiments, when the second chemical modification module 503 is specifically implemented, the initial negative electrode can be subjected to a second chemical modification operation in the following manner: the initial negative electrode is placed in an oxidation furnace; an oxidizing gas is introduced into the oxidation furnace; and the oxidation furnace is heated until a third specified temperature is reached; the oxidation furnace is controlled to maintain the third specified temperature for a third duration.

[0117] In some embodiments, after obtaining a target negative electrode that meets the requirements, the device may also be used to: perform electrochemical performance testing on the target negative electrode according to preset testing rules to obtain a first test result; perform battery cell performance testing on the target negative electrode to obtain a second test result; and detect whether the target negative electrode meets the requirements based on the first test result and the second test result.

[0118] It should be noted that the units, devices, or modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described by dividing them into various modules according to their functions. Of course, in implementing this specification, the functions of each module can be implemented in one or more software and / or hardware, or the module that implements the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection between the devices or units shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0119] As can be seen from the above, the composite anode preparation apparatus for flow batteries provided in the embodiments of this specification can, through multiple chemical modification operations, prepare a target anode with high conductivity, good hydrophilicity, and large specific surface area at a relatively low cost. Subsequently, this target anode can be used to further prepare flow batteries with high electrochemical performance and good cycle stability.

[0120] In a specific scenario example, the method for preparing a composite anode for a flow battery provided in this specification can be applied to achieve the preparation and testing of a composite anode for an all-vanadium redox flow battery. The specific implementation process can be found below.

[0121] In this scenario example, the energy density and efficiency of vanadium redox flow batteries are typically limited by the slow reaction kinetics of the anode material. The reaction kinetics of this anode material are closely related to factors such as the electrode's specific surface area, conductivity, and chemical stability. Specifically, during charge and discharge, vanadium redox flow battery anodes often face problems such as low electrochemical performance and poor cycle stability. This is mainly due to the low conductivity, poor hydrophilicity, and small specific surface area of ​​the anode material, so modification is necessary before using carbon-based electrodes. Existing preparation methods include surface heteroatom doping, surface oxidation activation, and the introduction of metal compounds or carbon-based catalysts. However, a single modification method cannot comprehensively address the existing shortcomings of the anode material.

[0122] To address the aforementioned problems and their root causes, and to solve the issues of small specific surface area, poor hydrophilicity, and low conductivity of graphite-based anode materials in vanadium redox flow batteries, this scenario provides a high-performance composite anode for vanadium redox flow batteries and its preparation method. This method utilizes a multi-stage surface modification process to prepare... A composite catalyst of a metal compound and nitrogen-doped carbon-based material was developed and loaded onto the surface of the negative electrode. The introduction of the composite catalyst improved the specific surface area of ​​the electrode, increased the number of reactive sites, and enhanced the electrode's conductivity and electron transport capability. Furthermore, during the multi-stage surface modification process, the negative electrode material itself was surface-doped with nitrogen (O), improving its hydrophilicity. By employing a multi-stage surface modification process, composite metal compounds can be simultaneously developed. Three modification strategies—preparation, nitrogen doping of carbon-based catalysts, and O doping of the negative electrode bulk surface—were employed to fabricate composite electrodes that achieved excellent electrochemical performance and cycle stability in all-vanadium redox flow batteries. The specific implementation process may include the following steps.

[0123] S1: Material selection and chemical modification.

[0124] In practice, transition metal molybdenum powder (Mo) and high specific surface area carbon-based materials (such as carbon nanotubes, graphene, porous carbon, etc.) can be used as the main components of the negative electrode catalyst. The carbon-based materials and molybdenum powder are mixed at a certain mass ratio using a ball mill to ensure uniform dispersion. Subsequently, the mixture is placed in a tube furnace, and nitrogen is introduced as a protective gas, while ammonia is introduced as a nitriding gas. The temperature is raised to 400-600 degrees Celsius (e.g., a first specified temperature) and maintained for 1-3 hours (e.g., a first duration) for chemical modification (e.g., a first chemical modification operation). During this process, ammonia reacts with molybdenum powder to generate molybdenum nitride (MoNx), while nitrogen doping occurs on the surface of the carbon-based material, forming nitrogen-doped carbon material. The chemically modified material exhibits enhanced surface activity and conductivity.

[0125] S2: High-temperature heat treatment.

[0126] In practice, the chemically modified composite catalyst material can be placed in a tube furnace, and argon (Ar) gas can be introduced as a protective gas for high-temperature heat treatment. During the heat treatment, the temperature is increased to 700-800 degrees Celsius (e.g., a second specified temperature) at a rate of 10 degrees Celsius / min and held for 2-3 hours (e.g., a second duration). This process further enhances the conductivity and structural stability of the composite catalyst material, eliminates internal stress, and improves its mechanical strength and electrochemical performance.

[0127] S3: Negative electrode preparation.

[0128] In practice, the heat-treated composite catalyst material and a binder (polyvinylidene fluoride or polytetrafluoroethylene) can be mixed at a mass ratio of 7-12:1, ground until homogeneous, and then the corresponding solvent for the binder can be added (N-methylpyrrolidone for polyvinylidene fluoride and deionized water for polytetrafluoroethylene) and grinding can continue until a homogeneous slurry is obtained (the initial negative electrode is obtained). The slurry is then coated onto the surface of a carbon-based negative electrode, which can be one of carbon felt, graphite felt, carbon cloth, or carbon paper.

[0129] S4: Catalyst and negative electrode surface modification.

[0130] In practice, the prepared electrode sheet (e.g., the initial negative electrode) can be placed in an oxidation furnace, and oxygen can be introduced as the oxidizing gas to perform surface oxidation treatment. During the oxidation treatment, the temperature is raised to 350-400 degrees Celsius (e.g., a third specified temperature) and held for 1 hour (e.g., a third duration) to form a layer of molybdenum oxide on the surface of the composite catalyst. Modified Simultaneously, oxygen doping is formed on the electrode body surface (e.g., a second chemical modification operation). Ultimately, a negative electrode for all-vanadium redox flow batteries with both high performance and excellent cycle stability is obtained.

[0131] S5: Performance Testing.

[0132] (1) Electrochemical performance testing: A three-electrode electrochemical testing system was constructed using a composite electrode as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum sheet as the counter electrode. The electrolyte was... The solution was subjected to electrochemical tests using a relevant electrochemical workstation. Electrochemical impedance spectroscopy (EIS) was performed at a frequency of 0.01–105 Hz with a starting voltage of -0.45 V. Cyclic voltammetry (CV) was performed at a voltage range of 0.9 V to 0.2 V with a scan rate of 10 mV / s.

[0133] (2) Battery cell performance testing: In the test, the carbon-based material (one of graphite felt, carbon felt, carbon cloth, or carbon paper) corresponding to the composite negative electrode was used as the positive electrode, the 2×2 cm^2 composite electrode under test was used as the negative electrode, the graphite plate was used as the current collector, and the DuPont Nafion 117 membrane was used as the ion exchange membrane. The initial electrolyte in the storage tank was... The volume was 12.5 mL, and the charge / discharge cutoff voltages were 1.6 and 0.8 V, respectively. The tests were conducted on a relevant battery testing system.

[0134] In this scenario example, the above method was applied to prepare the negative electrode using three different carbon-based materials, and corresponding performance tests were conducted to verify the results.

[0135] Example 1, Electrode fabrication and performance testing

[0136] The first step was material selection and chemical modification. High specific surface area carbon nanotubes (CNTs, approximately 1200 m² / g) and molybdenum powder (Mo) were selected as the main components of the electrode material. Carbon nanotubes and molybdenum powder were mixed at a mass ratio of 1:1. One gram of carbon nanotubes and one gram of molybdenum powder were weighed and placed in a ball mill, which was then milled at 300 rpm for 2 hours to ensure uniform mixing. The mixed material was transferred to a tube furnace, where nitrogen was introduced as a protective gas, and ammonia was introduced as a nitriding gas at flow rates of 200 sccm and 50 sccm, respectively. The temperature was raised to 500℃ and maintained for 2 hours for chemical modification. During this process, ammonia reacted with molybdenum powder to form molybdenum nitride (MoNx), while nitrogen doping occurred on the surface of the carbon nanotubes, forming nitrogen-doped carbon nanotubes (N-CNTs). After chemical modification, the material was naturally cooled to room temperature to obtain a surface-reinforced MoNx / N-CNT composite catalyst material.

[0137] The second step is high-temperature heat treatment. The MoNx / N-CNT composite catalyst material is placed in a tube furnace, and argon (Ar) gas is introduced as a protective gas at a flow rate of 200 sccm. The temperature is raised to 700 degrees Celsius at a rate of 10 degrees Celsius / min and held for 2 hours for high-temperature heat treatment. This process further enhances the conductivity and structural stability of the composite catalyst material. After heat treatment, it is allowed to cool naturally to room temperature.

[0138] The third step is the preparation of the negative electrode. The composite catalyst material and the binder polyvinylidene fluoride are mixed at a mass ratio of 10:1 and ground until homogeneous. Then, an appropriate amount of N-methylpyrrolidone is added, and grinding continues until a uniform slurry is formed. The slurry is then coated onto the surface of a graphite felt electrode, with each graphite felt having a MoNx / N-CNT loading of approximately 6 mg / cm².

[0139] Step 4: Catalyst and negative electrode surface modification. The prepared electrode sheet is placed in an oxidation furnace, and oxygen is introduced as the oxidizing gas at a flow rate of 100 sccm. The temperature is raised to 400 degrees Celsius and maintained for 1 hour to form a layer of molybdenum oxide (MoO2) on the surface of the composite catalyst. Modified Simultaneously, O doping (GF-O) is formed on the surface of the graphite felt electrode body. Ultimately, a composite anode for all-vanadium redox flow batteries, possessing both high performance and excellent cycle stability, was obtained. ).

[0140] Step 5: Electrochemical performance testing of the prepared electrodes. Electrochemical performance tests were performed on the electrodes. Figure 6 The cyclic voltammetry curve of the composite electrode shows oxidation and reduction peaks. The potential difference between the oxidation and reduction peaks is approximately 260 mV. The appearance of the reduction peak indicates that the hydrogen evolution side reaction is partially suppressed. Figure 7 for The Nyquist plots of the composite electrode and the pure graphite felt (GF) electrode were obtained through equivalent circuit simulation calculations. The charge transfer resistance is 0.91Ω, which is significantly lower than that of the pure GF electrode (3.2Ω), indicating that the composite electrode construction effectively enhances the charge transfer process.

[0141] Step 6: Battery performance testing. The prepared battery... The electrode was used as the negative electrode in a vanadium redox flow battery for performance testing. At a current density of 150 mA / cm², The battery with the negative electrode has a discharge volumetric capacity of 16.3 Ah / L. (See reference...) Figure 8 As shown. Figure 9 To achieve current densities of 50-300 mA / cm², The voltage efficiency curve of the flow battery with the negative electrode is shown. As the current density increases from 50 mA / cm^2 to 300 mA / cm^2, the voltage efficiency of the battery decreases. When the current density is 150 mA / cm^2, the voltage efficiency is about 83%, but when the current density is reduced again to 50 mA / cm^2, the voltage efficiency recovers to 94%, indicating that it has good electrochemical performance and stability. Figure 10 To achieve current densities of 50-300 mA / cm², The energy efficiency curve of the flow battery with the negative electrode is shown. As the current density increases from 50 mA / cm² to 300 mA / cm², the energy efficiency decreases. At a current density of 150 mA / cm², the energy efficiency is approximately 79%, but when the current density decreases again to 50 mA / cm², the energy efficiency recovers to approximately 88%, indicating good electrochemical performance and stability. Stability tests were conducted on the flow battery at a current density of 200 mA / cm². Figure 11 As shown, after 300 charge-discharge cycles, the battery's voltage efficiency and energy efficiency remained relatively stable, indicating that... Flow batteries with the negative electrode have good performance stability.

[0142] Example 2 Electrode fabrication and performance testing

[0143] The first step was material selection and chemical modification. High specific surface area graphene (1500 m² / g) and molybdenum powder (Mo) were selected as electrode materials. Graphene and molybdenum powder were mixed at a mass ratio of 1:1. 1.5 g of graphene and 1.5 g of molybdenum powder were weighed and placed in a ball mill, which was then ball-milled at 400 rpm for 3 hours to ensure uniform mixing. The mixed material was transferred to a tube furnace, and nitrogen was introduced as a protective gas, while ammonia was introduced as a nitriding gas at flow rates of 150 sccm and 100 sccm, respectively. Under a nitrogen atmosphere, the temperature was raised to 450 degrees Celsius and maintained for 1 hour for chemical modification. During this process, ammonia reacted with molybdenum powder to form molybdenum nitride (MoNx), and nitrogen doping occurred on the graphene surface, forming nitrogen-doped graphene (N-Gr). After chemical modification, the material was naturally cooled to room temperature to obtain a surface-reinforced MoNx / N-Gr composite catalyst material.

[0144] The second step is high-temperature heat treatment. The MoNx / N-Gr composite catalyst is placed in a tube furnace, and argon (Ar) is introduced as a protective gas at a flow rate of 250 sccm. The temperature is increased to 800 degrees Celsius at a rate of 10 degrees Celsius / min and held for 3 hours for high-temperature heat treatment. This process further enhances the electrical conductivity and structural stability of the composite catalyst material. After heat treatment, it is allowed to cool naturally to room temperature.

[0145] The third step is the preparation of the negative electrode. The composite catalyst material and the binder polytetrafluoroethylene are mixed at a mass ratio of 8:1, ground until homogeneous, and then an appropriate amount of deionized water is added to continue grinding until a uniform slurry is formed. The slurry is then coated onto the surface of a graphite felt electrode, with each graphite felt having a MoNx / N-Gr loading of approximately 6 mg / cm².

[0146] The fourth step is catalyst and negative electrode surface modification. The prepared electrode sheet is placed in an oxidation furnace, and oxygen is introduced as the oxidizing gas at a flow rate of 150 sccm. The temperature is raised to 350 degrees Celsius and maintained for 1 hour, allowing a layer of molybdenum oxide (MoO3)-modified MoNx-MoO3 to form on the surface of the composite catalyst, while simultaneously forming O doping (GF-O) on the surface of the graphite felt electrode body. Ultimately, a negative electrode for all-vanadium redox flow batteries with both high performance and excellent cycle stability is obtained. ).

[0147] Step 5: Electrochemical performance testing of the prepared electrodes. Electrochemical performance tests were performed on the electrode. Cyclic voltammetry curves showed that the potential difference between the oxidation and reduction peaks of the electrode was approximately 290 mV, indicating that the hydrogen evolution side reaction was partially suppressed. Electrochemical impedance spectroscopy (EIS) tests, calculated through equivalent circuit simulation, showed that the charge transfer resistance of the composite electrode was 1.05 Ω, significantly lower than that of the pure GF electrode (3.2 Ω), indicating that the composite electrode construction effectively enhanced the charge transfer process.

[0148] Step 6: Battery performance testing. The prepared battery... The electrode was used as the negative electrode in a vanadium redox flow battery for performance testing. At a current density of 150 mA / cm², The battery with the negative electrode has a discharge volumetric capacity of 14.9 Ah / L. At current densities of 50-300 mA / cm², with... The voltage efficiency of the flow battery with the negative electrode decreases as the current density increases from 50 mA / cm² to 300 mA / cm². At a current density of 150 mA / cm², the voltage efficiency is approximately 82%, but it recovers to 91% when the current density decreases again to 50 mA / cm², indicating good electrochemical performance and stability. Within the current density range of 50–300 mA / cm², the voltage efficiency... The energy efficiency of the flow battery with the negative electrode decreases as the current density increases from 50 mA / cm² to 300 mA / cm². At a current density of 150 mA / cm², the energy efficiency is approximately 76%, but it recovers to about 84% when the current density decreases again to 50 mA / cm², indicating good electrochemical performance and stability. Stability tests were conducted on the flow battery at a current density of 200 mA / cm². After 300 charge-discharge cycles, both the voltage efficiency and energy efficiency remained relatively stable, indicating good electrochemical performance. Flow batteries with the negative electrode have good performance stability.

[0149] Example 3 Electrode fabrication and performance testing

[0150] The first step was material selection and chemical modification. High-specific-surface-area activated carbon (AC, with a specific surface area of ​​1800 m² / g) and molybdenum powder (Mo) were selected as the main components of the electrode material. Activated carbon and molybdenum powder were mixed at a mass ratio of 2:1. 2 grams of porous carbon and 1 gram of molybdenum powder were weighed and placed in a ball mill, which was then milled at 350 rpm for 2.5 h to ensure uniform mixing. The mixed material was transferred to a tube furnace, where nitrogen was introduced as a protective gas, and ammonia was introduced as a nitriding gas at flow rates of 200 sccm and 50 sccm, respectively. The temperature was raised to 550 degrees Celsius and maintained for 3 hours for chemical modification. During this process, ammonia reacted with molybdenum powder to form molybdenum nitride (MoNx), and nitrogen doping occurred on the surface of the activated carbon, forming nitrogen-doped activated carbon (N-AC). After chemical modification, the material was naturally cooled to room temperature to obtain a surface-reinforced MoNx / N-AC composite catalyst material.

[0151] The second step is high-temperature heat treatment. The MoNx / N-AC composite catalyst material is placed in a tube furnace, and argon (Ar) gas is introduced as a protective gas at a flow rate of 250 sccm. The temperature is increased to 750 degrees Celsius at a rate of 10 degrees Celsius / min and held for 2 hours for high-temperature heat treatment. This process further enhances the electrical conductivity and structural stability of the composite catalyst material. After heat treatment, it is allowed to cool naturally to room temperature.

[0152] The third step is the preparation of the negative electrode. The composite catalyst material and the binder polyvinylidene fluoride are mixed at a mass ratio of 10:1 and ground until homogeneous. Then, an appropriate amount of N-methylpyrrolidone is added, and grinding continues until a uniform slurry is formed. The slurry is then coated onto the surface of a graphite felt electrode, with each graphite felt having a MoNx / N-AC loading of approximately 5 mg / cm².

[0153] Step 4: Catalyst and negative electrode surface modification. The prepared electrode sheet is placed in an oxidation furnace, and oxygen (O2) is introduced as the oxidizing gas at a flow rate of 100 sccm. The temperature is raised to 400 degrees Celsius and maintained for 1 hour to form a layer of molybdenum oxide (MoO2) on the surface of the composite catalyst. Modified Simultaneously, O doping (GF-O) was formed on the surface of the graphite felt electrode body. Ultimately, a composite anode for all-vanadium redox flow batteries, possessing both high performance and excellent cycle stability, was obtained. ).

[0154] Step 5: Electrochemical performance testing of the prepared electrodes. Electrochemical performance tests were performed on the electrode. Cyclic voltammetry curves showed that the potential difference between the oxidation and reduction peaks of the electrode was approximately 283 mV, indicating that the hydrogen evolution side reaction was partially suppressed. Electrochemical impedance spectroscopy was performed, and the charge transfer resistance of the composite electrode was calculated to be 0.98 Ω through equivalent circuit simulation.

[0155] Step 6: Battery performance testing. The prepared battery... The electrode was used as the negative electrode in a vanadium redox flow battery for performance testing. At a current density of 150 mA / cm², The battery with the negative electrode has a discharge volumetric capacity of 15.5 Ah / L. At current densities of 50-300 mA / cm², with... The voltage efficiency of the flow battery with the negative electrode decreases as the current density increases from 50 mA / cm² to 300 mA / cm². At a current density of 150 mA / cm², the voltage efficiency is approximately 84%, but it recovers to 92% when the current density decreases again to 50 mA / cm², indicating good electrochemical performance and stability. Within the current density range of 50–300 mA / cm², with… The energy efficiency of the flow battery with the negative electrode decreases as the current density increases from 50 mA / cm² to 300 mA / cm². At a current density of 150 mA / cm², the energy efficiency is approximately 77%, but it recovers to about 87% when the current density decreases again to 50 mA / cm², indicating good electrochemical performance and stability. Stability tests were conducted on the flow battery at a current density of 200 mA / cm². After 300 charge-discharge cycles, both the voltage efficiency and energy efficiency remained relatively stable, indicating good electrochemical performance. Flow batteries with the negative electrode have good performance stability.

[0156] The above scenario examples verify that the composite negative electrode preparation method for flow batteries provided in this specification produces a negative electrode material whose surface is coated with a transition metal compound / N-doped porous carbon material as a catalyst. This transition metal compound / N-doped porous carbon material significantly improves the electrode's specific surface area and conductivity, thereby enhancing the battery's charge / discharge efficiency and energy density. The surface modification and coating design of the electrode effectively improve its electrochemical stability and cycle life, reducing potential performance degradation during charge / discharge. The electrode exhibits excellent chemical stability, maintaining high electrochemical performance over long-term charge / discharge cycles. Furthermore, the preparation method is simple, scalable, and easily applicable for industrial production.

[0157] While this specification provides the steps of operation for the methods described in the embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible order of execution among many steps and does not represent the only possible order. In actual device or client product execution, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

[0158] Those skilled in the art will also know that, besides implementing the controller using purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller function as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0159] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer-readable storage media, including storage devices.

[0160] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions of this specification can essentially be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of this specification.

[0161] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. This specification can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0162] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations and modifications are possible without departing from the spirit of this specification, and it is intended that the appended claims cover such variations and modifications without departing from the spirit of this specification.

Claims

1. A method for preparing a composite negative electrode for a flow battery, characterized in that, include: By using molybdenum powder and carbon-based materials, a first chemical modification operation is performed to form molybdenum nitride, and nitrogen doping is formed on the surface of the carbon-based materials to obtain a composite catalyst material. The composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry; and the negative electrode slurry is coated onto the surface of a carbon-based negative electrode to obtain an initial negative electrode. A second chemical modification operation is performed on the initial negative electrode to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and oxygen doping is formed in the bulk of the initial negative electrode to obtain the target negative electrode that meets the requirements.

2. The method according to claim 1, characterized in that, The composite catalyst material obtained by using molybdenum powder and carbon-based materials and performing a first chemical modification operation includes: According to preset processing rules, molybdenum powder and carbon-based materials in a first preset ratio are obtained; and the molybdenum powder and carbon-based materials are ground and mixed using a ball mill to obtain a first mixed material. The first mixture is placed in a tube furnace; Nitrogen and ammonia are introduced into the tubular furnace according to a first gas flow rate and a second gas flow rate; and the tubular furnace is heated until a first specified temperature is reached; The tubular furnace is controlled to maintain a first specified temperature for a first duration.

3. The method according to claim 1, characterized in that, After obtaining the composite catalyst material, the method further includes: Argon gas is introduced into the tube furnace as a protective gas; and the tube furnace is heated according to a first heating rate until a second specified temperature is reached; The tubular furnace is controlled to maintain a second specified temperature for a second duration.

4. The method according to claim 1, characterized in that, The carbon-based material includes at least one of the following: carbon nanotubes, graphene, and porous carbon.

5. The method according to claim 1, characterized in that, The composite catalyst material is mixed with a matching binder and solvent to obtain a negative electrode slurry, comprising: Based on the composite catalyst material, obtain a binder that meets the second preset ratio; A second mixed material is obtained by grinding and mixing the composite catalyst material and the binder; A solvent compatible with the binder is added to the second mixture; and the mixture is ground and mixed to obtain a negative electrode slurry.

6. The method according to claim 1, characterized in that, The carbon-based negative electrode includes at least one of the following: a negative electrode made of carbon felt, a negative electrode made of graphite felt, a negative electrode made of carbon cloth, and a negative electrode made of carbon paper.

7. The method according to claim 1, characterized in that, The second chemical modification operation on the initial negative electrode includes: The initial negative electrode is placed in an oxidation furnace; An oxidizing gas is introduced into the oxidation furnace; and the oxidation furnace is heated until the third specified temperature is reached; The oxidation furnace is controlled to be maintained at a third specified temperature for a third duration.

8. The method according to claim 1, characterized in that, After obtaining the target negative electrode that meets the requirements, the method further includes: According to the preset test rules, the electrochemical performance of the target negative electrode is tested to obtain the first test result; The target negative electrode is subjected to single-cell performance testing to obtain a second test result. Based on the first test result and the second test result, determine whether the target negative electrode meets the requirements.

9. An apparatus for preparing a composite negative electrode for a flow battery, characterized in that, include: The first chemical modification module is used to form molybdenum nitride by performing a first chemical modification operation on molybdenum powder and carbon-based materials, and to form nitrogen doping on the surface of the carbon-based materials to obtain a composite catalyst material. The processing module is used to mix the composite catalyst material with a matching binder and solvent to obtain a negative electrode slurry; and to coat the negative electrode slurry onto the surface of a carbon-based negative electrode to obtain an initial negative electrode; The second chemical modification module is used to perform a second chemical modification operation on the initial negative electrode, so as to form a molybdenum nitride layer modified with molybdenum oxide on the surface of the composite catalyst material coated on the surface of the initial negative electrode, and to form oxygen doping in the bulk of the initial negative electrode, so as to obtain the target negative electrode that meets the requirements.

10. An electronic device, characterized in that, It includes a processor and a memory for storing processor-executable instructions, wherein the processor, when executing the instructions, implements the steps of the method according to any one of claims 1 to 8.

11. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 8.

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