KR101917931B1 - Fabricating method of bipolar plate for redox flow batteries - Google Patents

Abstract

There is provided a method of manufacturing a single layer or multilayer bipolar plate having excellent durability for a redox flow battery. By producing single or multi-layered bipolar plates using highly corrosion resistant binders and high electrically conductive materials, the redox flow cell is improved in durability, corrosion resistance and electrical conductivity. As a result, it can be used as a bipolar plate having excellent durability for a redox flow cell.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a bipolar plate for redox flow batteries,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bipolar plate for a redox flow battery, and more particularly, to a method for manufacturing a single layer or multi-layer bipolar plate having excellent durability for a redox flow battery.

Recently, renewable energy such as solar energy or wind energy is attracting attention as a method to suppress greenhouse gas emission, which is a major cause of global warming. However, such renewable energy is greatly influenced by the location environment and natural conditions. Furthermore, since the output fluctuation is significant, there is a disadvantage that the energy can not be continuously supplied evenly.

Therefore, it is important to develop a storage device capable of storing energy when the output is high and storing the energy when the output is low in order to equalize the output of energy. Typical mass storage devices such as lead accumulator, NaS battery, And Redox Flow Battery (RFB).

The redox flow cell consists of porous electrodes (anode and cathode), bipolar plate, and frame on both sides of the ion exchange membrane (diaphragm). Here, the bipolar plate is a plate for separating each cell of the stack, and is required to have conductivity so as to minimize the internal resistance of the cell. In addition, the bipolar plate is required to have a high mechanical strength (tensile strength) and a stretching property so as not to cause breakage due to deformation, since the bipolar plate can generate heat shrinkage due to pressure and temperature change due to the electrolytic solution.

But. The existing redox flow cell has low corrosion resistance and the anode electrolyte and the cathode electrolyte are charged and discharged in the form of different phases, and thus the commercialization is limited due to the deterioration of the battery efficiency due to the occurrence of ion precipitation This is a problem to be solved.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a single-layer or multi-layer bipolar plate for a redox flow battery.

According to an aspect of the present invention, there is provided a method of manufacturing a bipolar plate for a durable redox flow battery, comprising the steps of: providing a carbonized and highly purified phenol resin; mixing the phenol resin, the conductive filler, A step of mixing the additives to prepare a slurry, and a step of forming a multi-layer bipolar plate using the slurry.

Wherein the phenol resin is carbonized at 1300 ° C for 24 hours in the step of mixing the phenol resin, the conductive filler, the binder resin and the additive to produce a slurry.

Wherein the phenol resin is highly purified at 800 ° C for 24 hours in the step of preparing the slurry by mixing the phenol resin, the conductive filler, the binder resin and the additive, so that the carbon (C) is highly purified to 90% to 99.9% A method of manufacturing a bipolar plate can be provided.

The conductive filler may be at least one selected from the group consisting of graphite, carbon, carbon nanotubes (CNTs), vapor grown carbon fibers (carbon nanotubes), carbon nanotubes A method of manufacturing a bipolar plate including at least one of Vapor Grown Carbon Fiber (VGCF), KB (Ketjen Black), Active Carbon Powder, Carbon Fiber, Metal, and Ceramics.

The binder resin may include a thermoplastic resin or a thermosetting resin in the step of preparing the slurry by mixing the phenol resin, the conductive filler, the binder resin, and the additive.

The binder resin may be at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polypropylene (PP), polyethylene (PE), bipolar plates containing at least one of bipolar plates ≪ / RTI >

The solvent for dissolving the binder resin may provide a method for producing a bipolar plate containing N-methyl-2-pyrrolidone (NMP) or ethanol.

Wherein the additive includes one selected from N-methyl-ethyl-pyrrolidinium (MEP), quaternary ammonium and polybromide.

Wherein the slurry is formed into a multi-layered bipolar plate by coating one side of a single-layer bipolar plate with a slurry using a heating press and a doctor blade after the carbonization and high-refinement steps in the step of forming the multi-layered bipolar plate. A manufacturing method can be provided.

And forming a bipolar plate on one surface of the single-layer bipolar plate in the step of forming the multi-layer bipolar plate to manufacture a bipolar plate having a plurality of layers.

INDUSTRIAL APPLICABILITY According to the present invention, durability and corrosion resistance can be improved in a redox-flow battery by producing a single-layer or multi-layer bipolar plate using a binder which is carbonized and highly pure to improve durability and has high corrosion resistance.

In addition, by manufacturing a bipolar plate using a highly electrically conductive material, the electrical conductivity of the redox flow cell can be improved.

However, the effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a manufacturing procedure of a single-layer or multi-layer bipolar plate according to an embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are also provided to more fully describe the present invention to those skilled in the art. Therefore, the shape and size of the elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

The present invention relates to a method of manufacturing a single-layer or multi-layer bipolar plate having excellent durability for a redox flow battery.

Unlike conventional secondary batteries, redox flow batteries are an electrochemical storage device in which the active energy of the electrolyte is oxidized and reduced to charge and discharge, and the chemical energy of the electrolyte is stored directly as electrical energy. The components of the redox flow cell are a tank storing different active materials in different oxidation states, a pump circulating the active material during charging and discharging, and a cell separated by an ion exchange membrane.

As an active material, an electrolyte prepared by dissolving a transition metal such as V, Fe, Cr, Cu, Ti, Mn, and Sn in a strong acid aqueous solution is used. The produced electrolyte is not stored in the cell but stored in an external tank in a liquid state, and is supplied to the inside of the cell through the pump during charging and discharging. Also. The bipolar plate is located between both sides of the ion exchange membrane. Therefore, there is a problem that the performance is lowered due to problems such as precipitation of ions as the reaction progresses between the bipolar plate and the electrolyte. Therefore, it is essential to manufacture a bipolar plate having excellent durability and corrosion resistance. In the present invention, a single-layer or multi-layer bipolar plate is manufactured to produce a bipolar plate for a redox flow battery having excellent durability and corrosion resistance.

FIG. 1 is a diagram illustrating a process sequence of a bipolar plate according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, a diagram illustrating a process sequence of a bipolar plate according to the first embodiment is shown.

S10 is a step of providing a carbonized and highly purified phenolic resin.

Phenol resin is a thermosetting resin made of phenol and formaldehyde. The phenolic resin is excellent in heat resistance and dimensional stability. The phenolic resin is carbonized and highly pure. First, the phenol resin is carbonized and carbonized in a carbonization furnace at 1300 ° C for 24 hours to obtain a carbonized phenol resin powder having a fine particle size.

Subsequently, the carbonized phenol resin is put into a high-purity furnace and is highly purified at 800 DEG C for 24 hours. Therefore, the carbonized phenol resin is highly purified and the carbon (C) is highly purified to 90% to 99.9%. Thereby, a highly purified carbonized penol powder is produced.

S20 is a step of preparing a slurry by mixing a phenol resin, a conductive filler, a binder resin and an additive.

The phenolic resin is a highly purified carbonized penol. The conductive filler may be graphite, carbon, carbon nanotube (CNT), vapor grown carbon fiber, VGCF), KB (Ketjen Black), Active Carbon Powder, Carbon Fiber, Metal, and Ceramics. In addition, the binder resin includes thermoplastic or thermosetting resin, and the type of the binder resin is not limited as long as it is a material that can be used as a binder resin. However, the binder resin may include at least one of polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene (PE). In addition, the solvent for dissolving the binder resin may include N-methyl-2-pyrrolidone (NMP) or ethanol. Also, the additive may include one selected from N-methyl-ethyl-pyrrolidinium (MEP), quaternary ammonium and polybromide.

The phenol resin, the conductive filler, the binder resin, and the additive may be added and mixed at different ratios in the step of preparing the slurry by mixing the phenol resin, the conductive filler, the binder resin, and the additive.

However, the multilayer bipolar plate includes at least two slurries in the production examples. Hereinafter, six production examples are disclosed in the step of preparing a slurry by mixing the phenol resin, the conductive filler, the binder resin and the additive.

Production Example 1

10 g of a conductive filler, 10 g of a binder and 50 ml of a solvent were mixed at room temperature or room temperature with stirring for 12 hours to prepare a slurry.

Production Example 2

8 g of a conductive filler, 2 g of highly purified carbonized phenol, 10 g of a binder and 50 ml of a solvent were mixed at room temperature or room temperature with stirring for 12 hours to prepare a slurry.

Production Example 3

8 g of a conductive filler, 2 g of highly purified carbonized phenol, 5 g of a binder, 10 g of a metal oxide and 50 ml of a solvent were mixed at room temperature or room temperature with stirring for 12 hours to prepare a slurry.

Production Example 4

8 g of conductive filler, 2 g of highly purified carbonized phenol, 5 g of binder PVDF, 5 g of binder PP, 3 g of binder PE, 2 g of metal oxide and 50 ml of solvent were mixed at room temperature or room temperature with stirring for 12 hours to prepare a slurry.

Production Example 5

8 g of conductive filler, 2 g of highly purified carbonized phenol, 5 g of binder PVDF, 5 g of binder PP, 3 g of binder PE, 2 g of metal oxide and 50 ml of solvent were mixed at room temperature or room temperature with stirring for 12 hours to prepare a slurry.

Production Example 6

8 g of conductive filler, 2 g of highly purified carbonized phenol, 5 g of binder PVDF, 5 g of binder PP, 3 g of binder PE, 2 g of metal oxide, 50 ml of solvent and 1.5 g of additive MEP were mixed with stirring at room temperature or room temperature for 12 hours.

A bipolar plate is prepared from the slurry prepared in the above Production Example. The bipolar plate may be a single layer or a multilayer.

S30 is a step of manufacturing a single-layer or multi-layered bipolar plate.

First, a method of manufacturing a single-layer bipolar plate is described. The single-layer bipolar plate is manufactured on the basis of any one of slurries selected from Production Examples 1 to 6.

The slurry prepared in S20 is poured into a certain mold at a thickness of 3 mm to 7 mm and placed in an oven and cured at 120 ° C for 24 hours. After that, a single-layer bipolar plate is produced by applying a hot pressure for 5 hours at 300 ° C using a heating press.

Next, a method of manufacturing a multilayer bipolar plate is described. The multi-layered bipolar plate is produced on the basis of two slurries from Production Examples 1 to 6.

The slurry prepared in S20 may be coated on one side of a single layer bipolar plate by adding a heating press and a doctor blade process after carbonization, high-refinement, and may be made into a multi-layered bipolar plate. The slurry used to produce the monolayer and multilayer bipolar plates may comprise one or two sludges produced in the sludge preparation methods of Preparations 1 to 6. [ For example, one slurry prepared in the sludge production method of Production Examples 1 to 6 is spread on one surface of a single-layer bipolar plate at 100 탆 and cured in an oven at 120 캜 for 24 hours. Then, it is dried at room temperature for 4 hours. As a result, a bipolar plate is further formed on one surface of the single-layer bipolar plate to produce a multi-layer bipolar plate.

Therefore, durability and corrosion resistance can be improved in the redox-flow battery by manufacturing a single layer or multi-layer bipolar plate by using a binder which is carbonized and highly purified to improve durability and has high corrosion resistance. In addition, by manufacturing a bipolar plate using a highly electrically conductive material, the electrical conductivity of the redox flow cell can be improved.

Claims (10)

As a method for manufacturing a bipolar plate for a redox flow cell having high durability,
Providing a carbonized and highly purified phenolic resin powder;
Mixing the carbonized and highly purified phenol resin powder, the conductive filler, and the binder resin to prepare a slurry; And
Forming a multi-layered bipolar plate using the slurry,
The step of providing the carbonized and highly purified phenolic resin powder comprises: carbonizing the phenolic resin in a carbonization furnace;
Pulverizing the carbonized phenol resin to obtain a carbonized phenol resin powder; And
Wherein the carbonized phenol resin powder is highly purified in a high-purity furnace to obtain a carbonized phenol resin powder having a high carbon content of 90% to 99.9%. The method according to claim 1,
Wherein the carbonization of the phenol resin is carried out in a carbonization furnace at 1300 DEG C for 24 hours. The method according to claim 1,
Wherein the high-purity of the phenol resin is carried out at 800 DEG C for 24 hours in a high-purity furnace. The method according to claim 1,
The conductive filler may be selected from the group consisting of Graphite, Carbon, Carbon Nano Tube (CNT), Vapor Grown Carbon Fiber (VGCF), KB (Ketjen Black), Active Carbon Powder, (Carbon Fiber), metal, and ceramics. The method according to claim 1,
Wherein the slurry further comprises a metal oxide. The method according to claim 1,
Wherein the binder resin comprises at least one of polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene (PE). The method according to claim 1,
Wherein the solvent for dissolving the binder resin comprises N-methyl-2-pyrrolidone (NMP) or ethanol. The method according to claim 1,
Wherein the slurry further comprises an additive selected from N-Methyl-ethyl-pyrrolidinium (MEP), quaternary ammonium and polybromide. The method according to claim 1,
Wherein the step of forming the bipolar plate is performed by pouring a slurry into a mold and thermally curing the molten slurry, and then compressing the slurry by applying a hot pressure using a heating press to produce a single-layer bipolar plate. 10. The method of claim 9,
Wherein a bipolar plate is further formed on one surface of the single-layer bipolar plate using a doctor blade to produce a multi-layered bipolar plate.

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