CN111446460B - Multi-diameter electrode and preparation method and application thereof - Google Patents

Multi-diameter electrode and preparation method and application thereof Download PDF

Info

Publication number
CN111446460B
CN111446460B CN202010197653.9A CN202010197653A CN111446460B CN 111446460 B CN111446460 B CN 111446460B CN 202010197653 A CN202010197653 A CN 202010197653A CN 111446460 B CN111446460 B CN 111446460B
Authority
CN
China
Prior art keywords
diameter
electrode
spinning
fiber
needle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010197653.9A
Other languages
Chinese (zh)
Other versions
CN111446460A (en
Inventor
赵天寿
孙静
范新庄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangzhou HKUST Fok Ying Tung Research Institute
Original Assignee
Guangzhou HKUST Fok Ying Tung Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangzhou HKUST Fok Ying Tung Research Institute filed Critical Guangzhou HKUST Fok Ying Tung Research Institute
Priority to CN202010197653.9A priority Critical patent/CN111446460B/en
Publication of CN111446460A publication Critical patent/CN111446460A/en
Application granted granted Critical
Publication of CN111446460B publication Critical patent/CN111446460B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/96—Carbon-based electrodes
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D1/00—Treatment of filament-forming or like material
    • D01D1/02—Preparation of spinning solutions
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D01D5/0007—Electro-spinning
    • D01D5/0015—Electro-spinning characterised by the initial state of the material
    • D01D5/003—Electro-spinning characterised by the initial state of the material the material being a polymer solution or dispersion
    • D01D5/0038—Electro-spinning characterised by the initial state of the material the material being a polymer solution or dispersion the fibre formed by solvent evaporation, i.e. dry electro-spinning
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
    • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
    • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
    • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
    • D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
    • D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4282—Addition polymers
    • D04H1/43—Acrylonitrile series
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
    • D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
    • D04H1/728—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged by electro-spinning
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/18—Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
    • H01M8/184—Regeneration by electrochemical means
    • H01M8/188—Regeneration by electrochemical means by recharging of redox couples containing fluids; Redox flow type batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Dispersion Chemistry (AREA)
  • Inert Electrodes (AREA)
  • Fuel Cell (AREA)

Abstract

The invention provides a multi-diameter electrode and a preparation method and application thereof, and relates to the technical field of flow batteries. The multi-diameter electrode comprises two or more carbon fiber filament groups with the diameter ranges, the diameters of the carbon fiber filaments are 100nm-20 mu m, and the diameter sizes of two groups of carbon fiber filaments with the adjacent diameter ranges are different by at least 100 nm; wherein the diameter size of the fiber filament group with the minimum diameter is 100-1000nm, and the diameter size of the fiber filament group with the maximum diameter is 10-20 μm. The preparation method comprises the following steps: s1, dissolving polyacrylonitrile in a solvent to prepare spinning solutions with two or more mass concentrations; s2, carrying out multi-needle electrostatic spinning on the spinning solution to obtain a fiber membrane formed by stacking fiber yarns with multiple diameters and sizes; and S3, pre-oxidizing and carbonizing the fiber membrane to obtain the multi-diameter electrode. The multi-diameter electrode has larger specific surface area, can reduce the activation loss of the battery, improve the permeability and reduce the concentration polarization of the battery.

Description

Multi-diameter electrode and preparation method and application thereof
Technical Field
The invention relates to the technical field of flow batteries, in particular to a multi-diameter electrode and a preparation method and application thereof.
Background
In order to deal with the problems of global climate change, environmental pollution, energy shortage and the like, renewable energy sources such as solar energy, wind energy and the like are widely concerned and developed. However, these renewable energy power generation devices have the characteristics of volatility and intermittency, and therefore, it is necessary to utilize a large-scale energy storage system to implement efficient grid connection of the renewable energy power generation devices and implement peak shaving, frequency modulation, and the like of a power grid. In recent years, the flow battery has attracted much attention as an energy storage system because of its advantages of no regional limitation, independent capacity and power, good safety, long cycle life, and the like.
The electrode, one of the main components of the flow battery, not only provides the electrochemical reaction site, but also affects the transport of the electrolyte in the porous electrode, so its geometry and surface properties directly affect the battery performance. In order to reduce electrochemical polarization, ohmic polarization and concentration polarization, the electrode of the flow battery has the characteristics of large specific surface area, high permeability, high conductivity, high electrochemical activity and the like. At present, the electrode material of the flow battery is mainly carbon material, and comprises commercial carbon materials such as graphite felt, carbon paper, carbon cloth and the like. Commercial carbon materials have the characteristics of large pore size and porosity, and thus have high permeability. However, commercial carbon materials have small specific surface areas (typically not more than 1 m)2 g-1) And the redox reaction activity of the flow battery is low, and when the redox reaction is directly used for the flow battery, the output power density of the flow battery is greatly limited.
In recent years, some progress has been made in the preparation of nanoscale carbon fibers using electrospinning techniques and their application to flow batteries. Owing to the nanoscale carbon fiber size, carbon fibers produced by electrospinning generally have a large specific surface area (10 to 1000 m)2 g-1) (ii) a At the same time, however, the permeability of electrospun carbon electrodes is greatly reduced compared to commercial carbon electrodes, and thus direct use of electrospun carbon fiber electrodes in flow batteries results in greater concentration polarization, resulting in batteries that can only operate at lower current densities.
Disclosure of Invention
In view of the above, there is a need to provide a multi-diameter electrode, which has two or more sizes, can realize a large specific surface area while ensuring a high permeability of the electrode, can simultaneously reduce electrochemical polarization and concentration polarization of the battery, and can be adapted to redox flow batteries with different requirements.
A multi-diameter size electrode comprising two or more groups of carbon filaments having diameters in the range of 100nm to 20 μm, the diameter sizes of two groups of filaments in adjacent diameter ranges differing by at least 100 nm; wherein the diameter of the fiber filament group with the minimum diameter is 100-1000nm, and the diameter of the fiber filament group with the maximum diameter is 10-20 μm.
The multi-diameter electrode can greatly improve the specific surface area of the electrode on the premise of not improving the flow resistance of electrolyte, reduce the activation loss of the battery and simultaneously reduce the electrochemical polarization and concentration polarization of the battery. When the electrode is used for an all-vanadium redox flow battery, the battery can be enabled to be 300mA cm-2The energy efficiency under the operating current density is up to more than 80%. The electrode structure and the preparation method provided by the invention have wide adjustable range and are suitable for redox flow batteries with different requirements.
In one embodiment, the fiber has 2 fiber groups with diameters ranging from 100nm to 1000nm, 10-20 μm.
In one embodiment, the fiber filament has 3 groups of fiber filaments with diameters in the range of 100-1000nm, 1-10 μm and 10-20 μm.
In one embodiment, the fiber filament has 4 groups of fiber filaments with diameters in the range of 100-1000nm, 1-5 μm, 5-10 μm and 10-20 μm.
In one embodiment, the fiber has 5 fiber groups with diameters of 1000nm, 1-5 μm, 5-10 μm, 10-15 μm and 15-20 μm.
The invention also provides a preparation method of the multi-diameter electrode, which comprises the following steps:
s1, dissolving Polyacrylonitrile (PAN) in a solvent, and preparing spinning solutions with two or more mass concentrations according to the diameter range of each group of fiber yarns, wherein the mass fraction of the spinning solutions is 2-20%;
s2, carrying out multi-needle electrostatic spinning on the spinning solution to obtain a fiber membrane formed by stacking fiber yarns with multiple diameters;
and S3, pre-oxidizing the fiber membrane in air, and carbonizing the fiber membrane in an inert gas atmosphere to obtain the multi-diameter electrode.
According to the preparation method, the electrostatic spinning precursor solutions with different concentrations are prepared, and the multi-needle is matched for electrostatic spinning, so that two or more carbon fiber electrodes with the diameter sizes can be obtained, the size of the fiber filament is 100nm-20 mu m, and the adjustment and the control can be performed according to the situation. The obtained electrode with multiple diameters can greatly improve the specific surface area of the electrode on the premise of not improving the flow resistance of electrolyte, reduce the activation loss of the battery and simultaneously reduce the electrochemical polarization and concentration polarization of the battery.
In one embodiment, the polyacrylonitrile has an average molecular weight of 25000-200000g mol-1。
In one embodiment, the solvent is selected from: n, N-dimethylformamide and/or N, N-dimethylacetamide.
In one embodiment, the thickness of the fiber membrane is 100 μm-5 mm.
In one embodiment, the step S1 specifically includes: mixing polyacrylonitrile and a solvent, heating at 40-80 ℃ for 10-20h for dissolving, and preparing into spinning solution with 2-10 mass concentrations, wherein the mass fraction of the spinning solution is 2-20%, and the mass fraction difference between the concentrations is at least 1%.
In one embodiment, the mass fraction of the spinning solution with the lowest concentration is 5-12%, and the mass fraction of the spinning solution with the highest concentration is 12-15%.
In one embodiment, the spinning solution has two mass concentrations, which are 12% and 15%, respectively.
In one embodiment, the spinning solution has two mass concentrations, 10% and 15% respectively.
In one embodiment, the spinning solution has three mass concentrations, which are 5%, 10% and 15%.
In one embodiment, in step S2, the diameter of the needle is 0.2-2mm, and the advancing speed of the spinning solution is 0.2-2mL h-1The rotating speed of the receiving end rotating wheel is 10-1000rpm, the distance between the needle head and the receiver is 10-50cm, the voltage between the needle head and the receiving end is 10-50kV, and the temperature of electrostatic spinning is 20 DEGAbout 50 ℃ and a relative humidity of 20 to 70 percent.
It is understood that the number of different diameter needle types is equal to the number of different mass concentration spinning solution types. The spinning solutions with different mass concentrations are respectively connected with the needle heads with different diameters.
In one embodiment, 5 to 12 wt% of the dope is connected to a needle having an inner diameter of 0.40 to 1.07mm, and 12 to 15 wt% of the dope is connected to a needle having an inner diameter of 1.07 to 1.40 mm.
In one example, 12 wt% dope was attached to a 17G needle (1.07 mm ID) and 15 wt% dope was attached to a 15G needle (1.40 mm ID).
In one example, 10 wt% dope was attached to a 20G needle (internal diameter 0.60mm) and 15 wt% dope was attached to a 15G needle (internal diameter 1.40 mm).
In one example, 5 wt% dope was attached to a 22G needle (inner diameter 0.40mm), 10 wt% dope was attached to a 20G needle (inner diameter 0.60mm), and 15 wt% dope was attached to a 15G needle (inner diameter 1.40 mm).
In one embodiment, in the step S3, the pre-oxidation temperature is 220--1And the pre-oxidation time is 1-3 h.
In one embodiment, the inert gas is selected from: one or more of nitrogen, argon and hydrogen.
In one embodiment, the mass fraction of hydrogen in the inert gas is less than or equal to 10%.
In one embodiment, the carbonization temperature in step S3 is 800--1The carbonization time is 0.5-5 h.
The invention also provides an application of the multi-diameter electrode in the preparation of a flow battery. When the electrode is used for the all-vanadium redox flow battery, the battery can be ensured to be 300mA cm-2The energy efficiency under the operating current density reaches more than 80 percent.
Compared with the prior art, the invention has the following beneficial effects:
the multi-diameter electrode can greatly improve the electrode on the premise of not improving the flow resistance of the electrolyteThe specific surface area of the composite material can reduce the activation loss of the battery and simultaneously reduce the electrochemical polarization and concentration polarization of the battery. When the electrode is used for an all-vanadium redox flow battery, the battery can be enabled to be 300mA cm-2The energy efficiency under the operating current density is up to more than 80%. The electrode structure and the preparation method provided by the invention have wide adjustable range and are suitable for redox flow batteries with different requirements.
According to the preparation method, the electrostatic spinning precursor solutions with different concentrations are prepared, and the multi-needle is matched for electrostatic spinning, so that two or more carbon fiber electrodes with the diameter sizes can be obtained, the size of the fiber filament is 100nm-20 mu m, and the adjustment and the control can be performed according to the situation.
Drawings
FIG. 1 is a microscopic structure view of a dual-diameter electrode in an example;
FIG. 2 shows the total vanadium flow battery at 100-400mA cm in the example-2A constant current charging and discharging curve chart under different operating current densities;
FIG. 3 shows the total vanadium flow battery at 100-400mA cm in the example-2And (3) efficiency graphs of constant current charging and discharging under different operating current densities.
Detailed Description
To facilitate an understanding of the invention, a more complete description of the invention will be given below in terms of preferred embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
Example 1
A dual diameter electrode prepared by the following method:
s1, weighing 2.4g of polyacrylonitrile and 17.6g N, N-dimethylformamide, mixing, and heating in a water bath at 70 ℃ for 12 hours to prepare a spinning precursor solution (namely spinning solution) with the concentration of 12 wt%; weighing 3g of polyacrylonitrile and 17g N, N-dimethylformamide, mixing, heating and dissolving in 70 ℃ water bath to prepare 15 wt% spinning precursor solution;
s2, taking 10mL of 12 wt% spinning precursor solution into an injector, connecting a 17G needle (the inner diameter is 1.07mm), and setting the advancing speed of the solution to be 1mL h-1(ii) a In addition, 15mL of 15 wt% spinning precursor solution is connected with a 15G needle (the inner diameter is 1.40mm), and the solution advancing speed is set to be 1.5mL h-1. The voltage of electrospinning is set to be 17kV, the distance from the needle head to the receiving end is 20cm, and the rotating speed of the receiving rotating wheel is 200 rpm. The environment temperature of electrospinning is 25 ℃, the relative humidity is 55%, and the fiber membrane is taken down after spinning for 10 hours;
s3, placing the fiber membrane in a muffle furnace to be pre-oxidized for 2h at 250 ℃, wherein the heating rate is 1 ℃ for min-1(ii) a Carbonizing the preoxidized fiber filaments at 1100 deg.C for 1h under nitrogen protection atmosphere at a heating rate of 5 deg.C for min-1And finally, obtaining the product after carbonization is finished.
The microstructure of the dual-diameter electrode obtained in this example is shown in fig. 1, the diameter of the filament of the fine filament group is 800nm, the diameter of the filament of the coarse filament group is 10 μm, and the specific surface area of the electrode can reach 5.4m2 g-1。
Battery tests performed on the dual diameter electrode of this example:
taking a double-diameter electrode with the thickness of 700 mu m and the area of 2cm multiplied by 2cm as an all-vanadium redox flow battery electrode, and fastening and assembling the electrode, a polytetrafluoroethylene pad, a Nafion @ NR-212 diaphragm, a graphite plate with an interdigital flow field, a gold-plated copper current collecting plate, an aluminum end plate and an bakelite plate through bolts to form a single cell. Wherein the positive electrolyte is 20mL of 1M VO2++3M H2SO4The solution was 20mL of 1M V as a negative electrode electrolyte3++3M H2SO4And (3) solution. The electrolyte passes through a double-channel peristaltic pump for 76mL min-1The pump speed is cycled.
The vanadium redox flow battery based on the double-diameter electrode of the embodiment is at 100-400mA cm-2Different operating current densities within a rangeThe lower constant current charge-discharge curve is shown in fig. 2. The vanadium redox flow battery based on the double-diameter electrode of the embodiment is at 100-400mA cm-2The constant current charge and discharge efficiency at different operating current densities within the range is shown in fig. 3. Wherein, at 300mA cm-2At current density, the voltage efficiency of the cell was 81.39%, and the energy efficiency was 81.25%.
Example 2
A double diameter electrode was prepared substantially as in example 1, except that:
the concentrations of the two electrostatic spinning precursor solutions are respectively 10 wt% and 15 wt%, and the corresponding needles in the electrospinning process are respectively 20G (inner diameter of 0.60mm) and 15G (inner diameter of 1.40 mm). The advancing speed of the needle head is 1.0mL h-1And 1.5mL h-1. The double diameter size electrode was obtained through the same pre-oxidation and carbonization processes as in example 1.
The diameters of the filaments of the filament group of the double-diameter electrode obtained in this example were 500nm and 10 μm, respectively. The battery test shows that the current density is 300mA cm-2At current density, the voltage efficiency of the cell was 79.25% and the energy efficiency was 78.67%.
Example 3
A three-diameter electrode was prepared in substantially the same manner as in example 1, except that:
three different concentrations of electrostatic spinning precursor solutions are used, the concentrations are respectively 5 wt%, 10 wt% and 15 wt%, and the needles corresponding to electrospinning are respectively 22G (inner diameter 0.40mm), 20G (inner diameter 0.60mm) and 15G (inner diameter 1.40 mm). The advancing speed of the needle head is 0.5mL h-1，1.0mL h-1And 1.5mL h-1. Three-diameter electrodes were obtained by the same pre-oxidation and carbonization as in example 1.
The filament diameters of the filament groups of the three-diameter electrode obtained in this example were 200nm, 500nm and 10 μm, respectively. The battery test shows that the current density is 300mA cm-2At current density, the voltage efficiency of the cell was 75.48% and the energy efficiency was 74.82%.
Comparative example 1
A nanoscale diameter electrode is prepared by the following method:
s1, weighing 2g of polyacrylonitrile and 18g N, N-dimethylformamide, mixing, and heating in a water bath at 70 ℃ for 12 hours to prepare a 10 wt% spinning precursor solution;
s2, taking 10mL of 10 wt% spinning precursor solution into an injector, connecting a 20G (inner diameter is 0.6mm) needle, and setting the advancing speed of the solution to be 1mL h-1The voltage of electrospinning is set to be 20kV, the distance from the needle head to the receiving end is 20cm, and the rotating speed of the receiving rotating wheel is 200 rpm. The environment temperature of electrospinning is 25 ℃, the relative humidity is 45%, and the fiber membrane is taken down after spinning for 10 hours;
s3, placing the taken fiber membrane in a muffle furnace to be pre-oxidized for 2h at 250 ℃, wherein the heating rate is 1 ℃ for min-1Carbonizing the preoxidized fiber yarn at 1100 deg.C for 1h under nitrogen atmosphere at a heating rate of 5 deg.C for min-1And finally, obtaining the product after carbonization is finished.
The filament diameter of the single-diameter electrode obtained in this comparative example was about 500nm and the specific surface area was 50m2 g-1But the permeability is poor.
The single-diameter electrode prepared in the comparative example was assembled into an all-vanadium redox flow battery according to the battery assembly method of example 1 and subjected to a constant current charge-discharge test. At 300mA cm-2At current density, the cell energy efficiency was 70.6%.
Comparative example 2
A micron-sized diameter electrode is prepared by the following method:
s1, weighing 3g of polyacrylonitrile and 17g N, N-dimethylformamide, mixing, and heating in a water bath at 70 ℃ for 12 hours to prepare a 15 wt% spinning precursor solution;
s2, taking 10mL of 15 wt% PAN spinning precursor solution into a syringe, connecting a 15G (inner diameter of 1.40mm) needle, and setting the advancing speed of the solution to be 1mL h-1Setting the electrospinning voltage to be 20kV, setting the distance from a needle head to a receiving end to be 20cm, setting the rotating speed of a receiving rotating wheel to be 200rpm, setting the electrospinning environmental temperature to be 25 ℃, setting the relative humidity to be 55%, and taking down the fiber membrane after 10h of spinning;
s3, placing the taken fiber membrane in a muffle furnace to be pre-oxidized for 2h at 250 ℃, wherein the heating rate is 1 ℃ for min-1Will lead toCarbonizing the oxidized fiber at 1100 deg.C for 1h under nitrogen protection atmosphere, and heating at 5 deg.C for 5 min-1And finally, obtaining the product after carbonization is finished.
The filament diameter of the single-diameter electrode obtained in this comparative example was about 10 μm, and the specific surface area was 2.2m2 g-1The permeability is greatly improved.
The single-diameter electrode prepared in the comparative example was assembled into an all-vanadium redox flow battery according to the battery assembly method of example 1 and subjected to a constant current charge-discharge test. At 300mA cm-2At current density, the energy efficiency of the cell was 72.8%.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (6)

1. The multi-diameter electrode is characterized by comprising carbon fiber filament groups with two diameter ranges, wherein the diameters of the carbon fiber filament groups are 100nm-20 mu m, and the diameters of the carbon fiber filament groups are respectively 100nm and 1000nm and 10-20 mu m;
the multi-diameter electrode is prepared by the following preparation method:
s1, dissolving polyacrylonitrile in a solvent, and preparing two spinning solutions with mass concentrations according to the diameter range of each group of fiber yarns, wherein the mass fraction of the spinning solution is 2-20%;
s2, carrying out multi-needle electrostatic spinning on the spinning solution to obtain a fiber membrane formed by stacking fiber yarns with multiple diameters;
and S3, pre-oxidizing the fiber membrane in air, and carbonizing the fiber membrane in an inert gas atmosphere to obtain the multi-diameter electrode.
2. The multi-diameter electrode as claimed in claim 1, wherein the polyacrylonitrile has an average molecular weight of 25000-200000g mol-1(ii) a The solvent is selected from: n, N-dimethylformamide and/or N, N-dimethylacetamide; the thickness of the fiber membrane is 100 mu m-5 mm.
3. The multi-diameter-size electrode according to claim 1 or 2, wherein the step S1 is specifically: mixing polyacrylonitrile and a solvent, heating at 40-80 ℃ for 10-20h for dissolving, and preparing two spinning solutions with mass concentrations, wherein the mass fraction of the spinning solution is 2-20%, and the mass fraction difference between the concentrations is at least 1%;
in the step S2, the diameter of the needle is 0.2-2mm, and the advancing speed of the spinning solution is 0.2-2mL h-1The rotating speed of the rotating wheel at the receiving end is 10-1000rpm, the distance between the needle head and the receiver is 10-50cm, the voltage between the needle head and the receiving end is 10-50kV, the temperature of electrostatic spinning is 20-50 ℃, and the relative humidity is 20-70%.
4. The multi-diameter electrode as claimed in claim 1, wherein the pre-oxidation temperature is 220-300 ℃ and the temperature-increasing rate is 1-10 ℃ for min in step S3-1And the pre-oxidation time is 1-3 h.
5. The multi-diameter-size electrode according to claim 1, wherein in the step S3, the inert gas is selected from the group consisting of: one or more of nitrogen, argon and hydrogen; the carbonization temperature is 800-3000 ℃, and the heating rate is 2-10 ℃ for min-1The carbonization time is 0.5-5 h.
6. Use of the multi-diameter electrode of claim 1 in the manufacture of a flow battery.
CN202010197653.9A 2020-03-19 2020-03-19 Multi-diameter electrode and preparation method and application thereof Active CN111446460B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010197653.9A CN111446460B (en) 2020-03-19 2020-03-19 Multi-diameter electrode and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010197653.9A CN111446460B (en) 2020-03-19 2020-03-19 Multi-diameter electrode and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN111446460A CN111446460A (en) 2020-07-24
CN111446460B true CN111446460B (en) 2021-09-10

Family

ID=71650692

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010197653.9A Active CN111446460B (en) 2020-03-19 2020-03-19 Multi-diameter electrode and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN111446460B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112342689B (en) * 2020-10-21 2022-05-27 广州市香港科大霍英东研究院 Porous carbon fiber electrode for flow battery and preparation method thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102713039A (en) * 2010-01-21 2012-10-03 平松产业株式会社 Carbon fiber nonwoven fabric, carbon fibers, method for producing the carbon fiber nonwoven fabric, method for producing carbon fibers, electrode, battery, and filter
CN104241661A (en) * 2014-09-23 2014-12-24 中国科学院金属研究所 Preparation method for combination electrode for all-vanadium redox flow battery
CN105734831A (en) * 2014-12-10 2016-07-06 中国科学院大连化学物理研究所 Carbon nanofiber mat, preparation method thereof, and application thereof in all-vanadium redox flow battery
KR20160140260A (en) * 2015-05-29 2016-12-07 한국과학기술원 Dual-diameter 3-D nanofiber network coated with conductive thin film and its application as interlayer for Li-S battery
CN106876721A (en) * 2015-12-13 2017-06-20 中国科学院大连化学物理研究所 A kind of porous carbon nanofiber electrode used for all-vanadium redox flow battery and its preparation and application
CN108352534A (en) * 2015-04-01 2018-07-31 昭和电工株式会社 Electrode material, the electrode of redox flow batteries, redox flow batteries

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103422194B (en) * 2013-07-15 2015-09-30 清华大学 A kind of strong-hydrophobicity porous carbon nanofiber and preparation method thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102713039A (en) * 2010-01-21 2012-10-03 平松产业株式会社 Carbon fiber nonwoven fabric, carbon fibers, method for producing the carbon fiber nonwoven fabric, method for producing carbon fibers, electrode, battery, and filter
CN104241661A (en) * 2014-09-23 2014-12-24 中国科学院金属研究所 Preparation method for combination electrode for all-vanadium redox flow battery
CN105734831A (en) * 2014-12-10 2016-07-06 中国科学院大连化学物理研究所 Carbon nanofiber mat, preparation method thereof, and application thereof in all-vanadium redox flow battery
CN108352534A (en) * 2015-04-01 2018-07-31 昭和电工株式会社 Electrode material, the electrode of redox flow batteries, redox flow batteries
KR20160140260A (en) * 2015-05-29 2016-12-07 한국과학기술원 Dual-diameter 3-D nanofiber network coated with conductive thin film and its application as interlayer for Li-S battery
CN106876721A (en) * 2015-12-13 2017-06-20 中国科学院大连化学物理研究所 A kind of porous carbon nanofiber electrode used for all-vanadium redox flow battery and its preparation and application

Also Published As

Publication number Publication date
CN111446460A (en) 2020-07-24

Similar Documents

Publication Publication Date Title
CN111785978B (en) Porous electrode for flow battery and preparation method thereof
CN106560944B (en) Porous carbon fiber paper electrode material used for all-vanadium redox flow battery and its preparation and application
CN105671692B (en) The preparation method for the Nitrogen-rich porous carbon fiber electrode material that melamine resin is modified
CN110970628B (en) Nano carbon fiber and metal composite electrode and application thereof
CN111584895B (en) Oriented ordered electrode and preparation method and application thereof
Liu et al. Preparation and electrochemical studies of electrospun phosphorus doped porous carbon nanofibers
CN103762091A (en) Cellular porous manganese dioxide nanofiber preparing method and application of cellular porous manganese dioxide nanofiber in supercapacitor
CN106876721A (en) A kind of porous carbon nanofiber electrode used for all-vanadium redox flow battery and its preparation and application
CN110335759A (en) Load nickel hydroxide nano piece and the nanocrystalline carbon nano-fiber composite material and its preparation method and application of cobalt acid nickel
CN117525447B (en) Three-stage gradient porous electrode for all-vanadium redox flow battery and preparation method thereof
CN111446460B (en) Multi-diameter electrode and preparation method and application thereof
CN105734831B (en) A kind of carbon nano-fiber felt and its preparation and the application in all-vanadium flow battery
CN117488439A (en) Method for constructing high-activity gradient porous carbon nanofiber electrode material based on PVP-PAN double components and application of method
CN104716349B (en) A kind of preparation method of high activity electrode material used for all-vanadium redox flow battery
CN109449008B (en) Preparation method and application of self-supporting hollow core-shell structure electrode material
CN111477893A (en) Electrospun carbon nanofiber composite material with functional components distributed in longitudinal gradient manner, preparation method of electrospun carbon nanofiber composite material and application of electrospun carbon nanofiber composite material in vanadium battery
CN109305697B (en) Preparation method of nitrogen-containing hierarchical porous carbon nanotube film
CN112342689B (en) Porous carbon fiber electrode for flow battery and preparation method thereof
CN110571429A (en) Carbon-coated cobalt, titanium dioxide and lithium titanate composite material and preparation method thereof
CN115548401A (en) Preparation method of asymmetric vanadium battery based on functional carbon nanofiber electrode
CN115472848A (en) Preparation method of tin-loaded carbonaceous microsphere anchored carbon nanofiber electrode material and application of tin-loaded carbonaceous microsphere anchored carbon nanofiber electrode material in vanadium battery
CN109841851A (en) A kind of electrode material for all-vanadium flow battery and its preparation and application
CN111540915A (en) Carbon nanofiber electrode material embedded with carbonaceous microspheres and preparation method and application thereof
CN113707892A (en) Gas diffusion layer for fuel cell and method for preparing the same
KR20100025770A (en) Manufacturing process of carbon nanofiber for electronic double-layer capacitor by electrospinning

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant