KR20180003098A - Method for Manufacturing Membrane Dispersed Reinforcement for Redox Flow Battery - Google Patents

Abstract

A manufacturing method of a membrane distributing a reinforcing material for a redox flow battery sulfonates a non-fluorinated polymer and forms a membrane distributing a reinforcing material in order to improve a mechanical property. Therefore, an increase of water swelling is significantly decreased and mechanical performance is excellent.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing a membrane having a redox flow cell reinforcing material dispersed therein,

The present invention relates to a method for producing a membrane for a redox flow cell, which comprises sulfonating a non-fluorinated polymer and forming a membrane in which a reinforcing material is dispersed to improve mechanical properties, thereby significantly reducing water swelling, And a method for producing a membrane in which a reinforcing material for a flow cell is dispersed.

Renewable energy such as solar energy or wind energy is attracting attention in recent years as a method for suppressing the emission of greenhouse gases, which is a major cause of global warming. The renewable energy can not be continuously supplied because the output fluctuation is severe, and a time difference occurs between the point of time of energy production and the point of time of demand. Therefore, an energy storage system (Energy Storage System) which can store energy when the output of the renewable energy is high and use the stored energy when the output is low is important.

Among the various energy storage systems, research and development of redox flow cells are being actively carried out as secondary batteries which are effective for storing renewable energy.

A redox flow cell is an electrochemical storage device in which the active energy of an electrolyte is oxidized and reduced to charge and discharge the chemical energy of the electrolyte directly.

1, the redox flow battery 10 includes a stack 30 in which a plurality of unit cells (unit cells) 20 are stacked in series and a stack 30 in which oxidation states are different from each other And pumps 42 and 52 for circulating the active material during charging and discharging.

The electrolyte of the anode and the cathode uses an acidic aqueous solution in which an active material such as vanadium (V), iron (Fe), chromium (Cr) and the like and a transition metal such as tin (Stannum, Sn) are dissolved in a strong acid aqueous solution. The stack 30 is composed of unit cells 20 and two end plates 60 and 62.

The unit cells 20 and the end plates 60 and 62 are fastened by a plurality of tie rods 64.

2, the unit cells 20 basically include a membrane 22, a pair of electrodes 24 disposed on both sides of the membrane 22, an electrode 24, And a pair of bipolar plates 26 disposed on both sides of the bipolar plate.

In the redox flow cell 10, the anode electrolyte and the cathode electrolyte are circulated on both sides of the membrane 22, and ion exchange is performed. In this process, electrons move and charge and discharge are performed.

The redox flow battery 10 is known to be most suitable for an energy storage system because it has a longer life and can be manufactured as a medium to large size system of kW to MW.

Among the components of the redox flow cell 10, the membrane 22 plays the most important role in the performance of the battery, and is applied to a system using a strongly acidic substance containing an actual transition metal as an electrolytic solution, Low permeability and excellent mechanical properties are required.

Existing proton exchange membranes such as the Nafion of Dupont, Inc. are essential for driving the cell and are a typical factor for increasing the price of the battery.

Nafion membranes have high ionic conductivity and excellent chemical stability, but have poor permeation selectivity and deteriorate performance.

In addition, Selemion membrane has low ion selectivity due to its porous structure and low durability.

In order to solve such problems, the present invention relates to a method for sulfonating a non-fluorinated polymer, which comprises forming a membrane in which a reinforcing material such as nanoparticles is dispersed in order to improve mechanical properties, thereby remarkably lowering an increase in water swelling, And a method for manufacturing a membrane in which a reinforcing material for a flow cell is dispersed.

According to an aspect of the present invention, there is provided a method of manufacturing a membrane in which a reinforcing material for a redox flow cell is dispersed,

And sulfonating the non-fluorinated polymer and dispersing the reinforcing material to produce a membrane.

A method of manufacturing a membrane in which a reinforcing material for a redox flow cell is dispersed,

Polyether ether ketone (PEEK) polymer matrix, which is a non-fluorinated polymer, is dried at 100 ° C. to completely remove water, and then dissolved in 98% sulfuric acid at room temperature;

Conducting the sulfonation reaction for 24 hours while maintaining the reaction temperature constant at a constant temperature after the polyether ether ketone is dissolved;

Cooling the resulting mixture to ice water to form a solidified SPEEK (sulfonated polyether ether ketone);

Washing the prepared SPEEK with distilled water until the pH of the SPEEK becomes 5 or more and filtering it under reduced pressure to remove residual sulfuric acid;

Drying the washed SPEEK in an oven at 100 ° C for 12 hours, dissolving in an organic solvent for 12 hours,

Mixing the SPEEK dissolved in the organic solvent with 1 to 10 wt% of a reinforcing material for reinforcing mechanical properties; And

And drying the solvent at 60 DEG C while distributing the solution in which SPEEK is dissolved over a flat plate or passing through a roller, thereby producing a membrane.

According to the above-mentioned constitution, the present invention has an effect of manufacturing a redox flow cell having a thin thickness and excellent mechanical and chemical performance by producing a membrane using a non-fluorinated polymer.

The present invention has an effect of preventing the deterioration of physical properties by water swelling and improving mechanical properties by preparing a membrane in which a non-fluorinated polymer is sulfonated and a reinforcing material is dispersed.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view of a general redox flow cell. FIG.
FIG. 2 is a cross-sectional view showing the configuration of the unit cell in FIG.
3 is a view illustrating a method of manufacturing a membrane in which a reinforcement material for a redox flow cell according to an embodiment of the present invention is dispersed.
4 is a flowchart illustrating a method of manufacturing a membrane in which a reinforcement material for a redox flow cell according to an embodiment of the present invention is dispersed.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

The present invention provides a novel membrane for improving performance of a redox flow cell and a method of manufacturing the same.

FIG. 3 is a view showing a method of manufacturing a membrane in which a reinforcing material for a redox flow cell is dispersed according to an embodiment of the present invention, and FIG. 4 is a view illustrating a method of manufacturing a membrane in which a reinforcing material for a redox- Fig.

Referring to FIG. 3, a method of manufacturing a membrane in which a reinforcing material for a redox flow cell is dispersed according to an embodiment of the present invention includes drying a polyether ether ketone (PEEK) polymer matrix, which is a non- After the water is completely removed, it is dissolved in 98% sulfuric acid at room temperature (S100).

The membrane of the present invention uses PEEK, which is a non-fluorinated polymer, but it is not limited thereto, and may include various non-fluorinated polymers such as polystyrene and PAES (Polyarylene Ethersulfone).

After the step S100, the membrane is completely dissolved, and the sulfonation reaction is carried out for 24 hours while maintaining the reaction temperature at 60 DEG C (S102). Here, the sulfonation temperature and time may be varied to control the degree of sulfonation during the course of the sulfonation reaction.

The redox flow cell of the present invention is to produce a membrane through sulfonation of a non-fluorinated polymeric material.

After step S102, the membrane is cooled by cooling the reaction product in ice water after a predetermined reaction time has elapsed, to produce a solidified SPEEK (sulfonated polyether ether ketone) (S104).

 In the manufacturing method of the membrane, the SPEEK prepared in the step S104 is washed with distilled water until the pH becomes 5 or more, and filtered under reduced pressure to remove the remaining sulfuric acid (S106).

After the step S106, the washed SPEEK is dried in an oven at 100 ° C for 12 hours, and then dissolved in N-methyl-2-pyrrolidone (NMP) as an organic solvent for 12 hours (S108). N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used as the organic solvent depending on the sulfonation degree and solubility of SPEEK.

After the step S108, SPEEK dissolved in an organic solvent is mixed with 1 to 10 wt% of a reinforcing material such as nanoparticles for enhancing mechanical properties (S110).

In order to improve the ion exchange capacity of the SPEEK membrane, it is necessary to mix various kinds of reinforcing materials including nanoparticles in order to solve the mechanical properties (swelling, cross over, low tensile strength, etc.) To increase the ion exchange capacity and ion selectivity of the membrane, effectively increasing the mechanical properties.

In order to obtain the desired ionic conductivity of the non-fluorine-based membrane, the degree of sulfonation must be increased. However, as the sulfonation increases, the degree of water swelling increases and mechanical strength is significantly lowered. To overcome this problem, a certain amount of reinforcing particles are mixed with SPEEK.

The reinforcing material is not limited to the following examples. The reinforcing material may be a reinforcing material used for reinforcing the properties of a composite material such as fiberglass, aramid fiber, polyethylene fiber, and polymer fiber. To be used in a certain amount.

 The reinforcing material may be selected from fiberglass, aramid fiber, carbon fiber, polyethylene fiber and polymer fiber. The reinforcing material may be a mixture of long fiber and chopped fiber.

Depending on the kind of the organic solvent, the reinforcing material can selectively use hydrophobic and hydrophilic nanoparticles, and the silica nanoparticles, nanoclays, carbon black, carbon nanotubes (CNT), graphene, tungsten oxide have.

The stiffener may vary in content depending on the desired mechanical properties. In this case, the degree of dispersion of the stiffener has the greatest influence on the performance of the thin film. For this purpose, the reinforcing particles are dispersed uniformly and uniformly in the solvent by using a sonicator, a dispersant, a pneumatic dispersion and a centrifuge.

In addition, SPEEK membranes can be added with a low molecular weight polyethylene glycol (PEG) as a plasticizer for surface bonding between the membrane and the electrode.

Next, in step S110, the membrane is prepared by distributing the SPEEK-dissolved solution on a flat plate or by drying the solvent at 60 DEG C while passing between rollers (S112).

In step S112, the thickness of the membrane may be adjusted by repeating the casting process of the SPEEK dissolved in the organic solvent.

The membrane thus prepared can be further impregnated with 98% sulfuric acid, and a step of replacing sulfuric acid and PEG (polyethylene glycol) at 60 ° C for 12 hours can be added.

The present invention relates to a membrane made by dispersing a reinforcing material after sulfonating (SPEEK) polyether ether ketone (PEEK), which is a non-fluorinated polymer, and has excellent heat resistance, mechanical strength, moisture absorption and electrochemical properties, It is possible to produce a reinforced membrane membrane which is thin and excellent in mechanical performance.

In particular, the membrane of the present invention can significantly increase the degree of water swelling, which has been the most problematic in existing SPEEK membranes, through dispersion of the stiffener, thereby increasing the sulfonation time.

Accordingly, the membranes of the present invention can greatly increase hydrogen ion conductivity and improve cell performance.

The embodiments of the present invention described above are not implemented only by the apparatus and / or method, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

10: redox flow cell
20: Unit cell
22: Membrane
24: Electrode
26: Separator plate
30: Stack
40, 50: tank
42, 52: pump
60, 62: End plate

Claims (6)

A method for manufacturing a redox flow battery membrane,
And sulfonating the non-fluorinated polymer and dispersing the reinforcing material to prepare a membrane. The method according to claim 1,
Wherein the step of fabricating the membrane comprises:
Polyether ether ketone (PEEK) polymer matrix, which is a non-fluorinated polymer, is dried at a predetermined temperature to completely remove water, and then dissolved in sulfuric acid at room temperature;
Conducting the sulfonation reaction while maintaining the reaction temperature at a constant temperature after the polyether ether ketone is dissolved;
The sulfonated reaction is followed by cooling to produce solidified SPEEK (sulfonated polyether ether ketone).
Drying the SPEEK at a predetermined temperature and dissolving the SPEEK in an organic solvent; And
And dispersing the SPEEK-dissolved solution on a flat plate, or drying the solvent while passing the rollers, thereby producing a membrane. 3. The method of claim 2,
Wherein the step of fabricating the membrane comprises:
Wherein the SPEEK is washed with distilled water and filtered under reduced pressure to remove residual sulfuric acid. 3. The method of claim 2,
Wherein the step of fabricating the membrane comprises:
Further comprising the step of mixing the SPEEK dissolved in the organic solvent with a reinforcement material for strengthening the mechanical properties of the reinforcement material. The method according to claim 1,
Depending on the type of the organic solvent, the reinforcing material may be selected from a hydrophobic and hydrophilic reinforcing material, and one of silica nanoparticles, nano-clay, carbon black, carbon nanotube (CNT), graphene, and tungsten oxide Wherein the reinforcing material for a redox flow cell is dispersed. The method according to claim 1,
Wherein the reinforcing material is selected from the group consisting of glass fiber, aramid fiber, carbon fiber, polyethylene fiber and polymer fiber in the form of fibers and a mixture of long fibers and chopped fibers in a predetermined amount A method for manufacturing a membrane in which a redox flow cell reinforcing material is dispersed.

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