KR101494289B1 - Polymer electrolyte composite, method for producing the same and energy storage comprising the polymer electrolyte composite - Google Patents

Abstract

The present invention relates to a polymer electrolyte and, more specifically, to a polymer electrolyte porous composite membrane with improved ion transfer and permeability characteristics by including nanoporous inorganic particles, to a method for producing the porous composite membrane, and to an energy storage device including the porous composite membrane. The polymer electrolyte porous composite membrane includes a porous support membrane; an immersion layer formed to cover the porous support membrane; and a coating layer formed on the immersion layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer electrolyte composite, a method for producing the porous composite membrane, and an energy storage device including the porous composite membrane.

The present invention relates to a polymer electrolyte, and more particularly, to a polymer electrolyte porous composite membrane including nanoporous inorganic particles having enhanced ion transmission and permeability, a method for producing the porous composite membrane, and an energy storage device including the porous composite membrane It is about.

Redox Flow Battery (RFB) is a compound of Reduction, Oxidation, and Flow. It is a term used to describe a water-soluble electrolytic solution in which a metal ion with a variable constant is dissolved in a unit cell And the charging and discharging are carried out while passing through the electrochemical system. The basic structure of the RFB consists of a tank for storing the electrolyte solution, a pump for circulating the electrolyte solution, an anode and a cathode, and a polymer electrolyte membrane located between the two electrodes.

Polymer electrolyte membranes used as ion exchange resins or ion exchange membranes have been used for decades and have been studied steadily. Recently, numerous studies have been conducted on ion exchange membranes as mediators for ion transfer in various fields.

The electrode material is divided into a carbon felt electrode and an inactive electrode. The active material is used by dissolving a transition metal such as V, Fe, Cr, Cu, Ti, Mn and Sn in a strong acidic aqueous solution. As the polymer membrane used herein, it is preferable to use a polymer having a high ion selectivity. Examples of commercially available polymer membranes include Nafion manufactured by DuPont of America, CMV, AMV and DMV of Asagi Glass, Japan. Among these, Nafion, which is a perfluoropolyether having a relatively high chemical stability and a high hydrogen ion conductivity, has excellent performance, but has not been widely practically used because of its disadvantage of high unit cost, poor dimensional stability, and high methanol permeability.

In order to solve the problems of the conventional commercialized polymer membrane, researches on a new hydrocarbon-based proton conductive material having a relatively low permeability have been actively carried out. Typical examples thereof include polyimide, polyetheretherketone, polyethersulfone, and polybenzimidazole.

However, such a hydrocarbon-based polymer electrolyte membrane also has a problem of low dimensional stability due to high moisture content at the time of hydration and low durability, which makes it difficult to realize excellent performance of RFB. To improve this, a polymer electrolyte composite There is a continuing need for research and development of membrane production methods.

The present inventors have completed the present invention by developing a polymer electrolyte composite membrane having a novel composition including nanoporous inorganic particles.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polymer electrolyte composite porous membrane having a high ionic conductivity, a low permeability, and excellent chemical and physical stability of a membrane, an energy storage device comprising the porous composite membrane, And a water treatment apparatus.

Another object of the present invention is to provide a polymer electrolyte composite porous membrane which can improve cell performance and long-term performance without causing a decrease in the stability of the polymer electrolyte composite membrane even when driven for a long period of time by improvement in mechanical properties, And an energy storage device or a water treatment device including the porous composite membrane.

The object of the present invention is not limited to the above-mentioned objects, and although not explicitly mentioned, the object of the invention which can be recognized by a person skilled in the art from the description of the detailed description of the invention .

In order to achieve the above-mentioned object of the present invention, firstly, the present invention provides a porous membrane, An impregnation layer formed by surrounding the porous support membrane; And a coating layer formed on the impregnated layer. The present invention also provides a polymer electrolyte porous composite membrane comprising:

In a preferred embodiment, the porous support membrane is made of a material selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polyphenylene oxide (PPO), polybenzimidazole (PBI) ), Polyvinylidene fluoride (PVdF), polyvinyl chloride (PVC), or copolymerized polymers obtained by polymerizing these monomers, and has pores having a diameter of 10 nm or more.

In a preferred embodiment, the impregnated layer comprises a sulfonated polymer and an amphiphilic polymer.

In a preferred embodiment, the sulfonated polymer is a polymer obtained by grafting polystyrenesulfonic acid (PSSA) to the main chain of Nafion, Flemion, Ashiflex, polytetrafluoroethylene (PTFE), polyvinylidene A polymer obtained by grafting polystyrene sulfonic acid (PSSA) to a fluoride (PVdF) main chain, a sulfonated polysulfone, a sulfonated polyarylene ether sulfone, a sulfonated polyether ether sulfone, a sulfonated polyether sulfone , Sulfonated polyimides, sulfonated polyimidazoles, sulfonated polybenzimidazoles, sulfonated polyether benzimidazoles, sulfonated polyarylene ether ketones, sulfonated polyether ether ketones, sulfonated Polyether ketones, sulfonated polyether ketone ketones, sulfonated polystyrenes, sulfonated polyphenylene oxides, sulfonated polydimethylphenylen oxides, sulfonated poly In this case, it is preferable to use a compound selected from the group consisting of tilphenylene oxide, sulfonated polydiphenylphenylene oxide, brominated polyphenylene oxide sulphonic acid, brominated polydimethylphenylene oxide sulphonic acid, brominated polydiethylphenylene oxide sulphonic acid and brominated polydiphenylphenylene oxide sulphonic acid Selected from the group constituted.

In a preferred embodiment, the amphiphilic polymer has at least one hydrophilic segment having a hydroxyl group and a hydrophobic segment at the same time.

In a preferred embodiment, the sulfonated polymer has a number average molecular weight (Mn) of 1,000 to 1,000,000 and a weight average molecular weight (Mw) of 10,000 to 1,000,000.

In a preferred embodiment, the coating layer comprises a fluorinated polymer and nanoporous inorganic particles.

In a preferred embodiment, the nanoporous inorganic particles are formed in at least one material selected from the group consisting of silica, alumina, zirconia, zeolite, titanium, and graphen oxide.

In a preferred embodiment, the nanoporous inorganic particle has a -OH group in the functional group of the surface partly substituted with -SO ₃ H group, and the pore diameter of the particle is 0.1 to 100 nm.

In a preferred embodiment, the fluorine-based polymer is at least one selected from the group consisting of Nafion, Asiflex, Flemion, polyvinylidene fluoride, hexafluoropropylene, trifluoroethylene and polytetrafluoroethylene .

In a preferred embodiment, the thickness of the polymer electrolyte porous composite membrane in the non-humidified state is 5 to 500 mu m.

The present invention also provides a method for preparing a porous support membrane, comprising: preparing a porous support membrane; Forming an impregnated layer on the porous support membrane with the polymer solution for impregnation layer prepared; And forming a coating layer using a nanoparticle dispersion solution for a coating layer prepared on the impregnated layer.

In a preferred embodiment, the step of preparing the porous support membrane comprises a pre-treatment step of washing the porous support membrane with at least one solution selected from the group consisting of alcohol, acetone, acetic acid, sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, hydrogen peroxide solution do.

In a preferred embodiment, the polymer solution for the impregnated layer is obtained by uniformly dispersing a sulfonated polymer and an amphipathic polymer in a solvent.

In a preferred embodiment, the step of forming the impregnated layer includes impregnating the porous support membrane with the polymer solution for the impregnated layer, and diecasting both surfaces of the impregnated porous support membrane.

In a preferred embodiment, the nanoparticle dispersion solution for a coating layer is obtained by dispersing nanoporous inorganic particles in a fluorinated polymer solution.

In a preferred embodiment, the nanoporous inorganic particle has a -OH group in the functional group of the surface partly substituted with -SO ₃ H group, and the pore diameter of the particle is 0.1 to 100 nm.

The present invention also provides an energy storage device comprising any one of the above-described polymer electrolyte porous composite membrane or the polymer electrolyte porous composite membrane produced by any of the above-described manufacturing methods.

In a preferred embodiment, the energy storage device is a secondary battery or a fuel cell.

The present invention also provides a water treatment apparatus comprising any one of the above-described polymer electrolyte porous composite membrane or a polymer electrolyte porous composite membrane produced by any one of the above-described manufacturing methods.

The present invention has the following excellent effects.

First, according to the present invention, there is provided a polymer electrolyte composite porous membrane having a high ion conductivity and low permeability and excellent chemical and physical stability of a membrane, a method for producing the porous composite membrane, an energy storage device comprising the porous composite membrane, Device can be provided.

In addition, according to the present invention, it is possible to improve the cell performance and the long-term performance by preventing the stability of the polymer electrolyte composite membrane from being deteriorated even if the polymer electrolyte membrane is driven for a long time due to the improvement of mechanical properties. And an energy storage device or a water treatment device including the porous composite membrane.

These technical advantages of the present invention are not limited to the above-mentioned technical scope, and even if not explicitly mentioned, the effect of the invention which can be recognized by a person skilled in the art from the description of the concrete contents for carrying out the invention Of course.

1 is a cross-sectional photograph of a porous support membrane included in a porous composite membrane according to an embodiment of the present invention.
2 is a photograph of a surface of a polymer electrolyte porous composite membrane including the porous support membrane shown in FIG.
3 is a cross-sectional photograph of a polymer electrolyte porous composite membrane including the porous support membrane shown in FIG.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Accordingly, the terms used in the present invention should not be construed to be mere terms, but should be interpreted based on the ordinary meanings of the terms and contents described throughout the specification of the present invention.

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

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

Technical features of the present invention reside in the composition and structure of a polymer electrolyte composite membrane which maintains low permeability, high ion conductivity and durability. That is, when a coating layer composed of a dispersion formed by dispersing nanoporous inorganic particles in a fluorinated polymer solution on a porous support film is formed, ion transmission and permeability characteristics can be controlled.

Therefore, the polymer electrolyte porous composite membrane of the present invention comprises a porous support membrane; An impregnation layer formed by surrounding the porous support membrane; And a coating layer formed on the impregnated layer.

The porous support membrane is formed with pores having a diameter of 10 nm or more. The porous support membrane is not limited as long as it has the characteristics of a polymer electrolyte. Examples of the porous support membrane include polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (Polyvinylidene fluoride), polyvinyl chloride (PVC), or copolymerized polymers obtained by polymerizing these monomers, such as polyvinylidene fluoride (PPO), polybenzimidazole (PBI), polyimide Or may be a barrier lid containing one or more polymeric materials selected.

The impregnated layer is formed by surrounding the porous support membrane, and may be composed of a sulfonated polymer and an amphiphilic polymer. For example, the porous support membrane may be formed by immersing a porous support membrane in a polymer solution for an impregnated layer containing a sulfonated polymer and an amphiphilic polymer.

The amphiphilic polymer contained in the impregnated layer of the present invention may be any known material as long as it is a polymer material having at least one hydrophilic segment having a hydroxyl group and a hydrophobic segment at the same time. In addition, the amphiphilic polymer may be used singly or in combination of two or more. Examples of amphiphilic polymers include Urethane Acrylate Nonionomer (UAN), poly (isobutylene-b-methyl vinyl ether), poly (styrene-b-hydroxyethyl vinyl ether) (ethylene glycol) vinyl ether-b-isobutyl vinyl ether), poly (a-methylstyrene-b-2-hydroxyethyl vinyl ether), poly (2- (1-pyrrolidonyl) ethyl vinyl ether-b-isobutyl vinyl ether). PEP-PEO (PEP = poly (ethylenepropylene)), poly (N- (2-vinylpyridine) vinyl-2-pyrrolidone-co-acrylic acid, poly (ethylene oxide) -b-poly (L-lysine) aspartate, poly (ethylene oxide) -b-Poly (ethylene oxide) -b-poly (propylene oxide), poly (ethylene oxide) -Oligo (methacrylate), and the like may be used.

As the sulfonated polymer, any known sulfonated polymer material may be used as far as it has hydrophilicity and excellent hydrogen ion conductivity. It is preferable that an aromatic compound linked by an ether bond is used between aromatic compounds. These aromatic compounds preferably contain a sulfonated aromatic copolymer in which at least one sulfonic acid group or sulfonic acid salt substituent group-containing unit chains are spaced apart from each other by a predetermined distance, and the number average molecular weight (Mn) is 1,000 to 1,000,000 And a weight average molecular weight (Mw) of 10,000 to 1,000,000.

When the number of moles of the repeating unit is less than 1 mol%, the hydrogen ion conductivity is low. When the molar amount of the repeating unit is more than 70 mol%, the number of repeating units of the sulfonic acid group or sulfonic acid salt substituent is preferably in the range of 1 to 70 mol% The dimensional change largely occurs and stability can not be secured. , More preferably 20 to 60 mol%, and still more preferably 30 to 50 mol%.

For example, the sulfonated polymer may be a polymer resin having hydrogen ion conductivity. Specifically, the sulfonated polymer may have a cation exchanger selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a phosphonic acid group and derivatives thereof Any polymer resin may be used. More specifically, there may be mentioned sulfonated fluorinated polymers, benzimidazole polymers, polyimide polymers, polyamide polymers, polyphenylene oxide polymers, polyarylene ether polymers, polyetherimide polymers, polyphenylene sulfide Based polymer, polysulfone polymer, polyether sulfone polymer, polyether ketone polymer, polyether-ether ketone polymer, polyphosphazene polymer, polystyrene polymer, radiation-grafted FEP-g-polystyrene radiation-grafted FEP-g-polystyrene, radiation-grafted PVDF-g-polystyrene, and polyphenylquinoxaline-based polymers. And more specifically sulfonated poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), tetrafluoroethylene containing sulfonic acid groups Poly (2,2'-m-phenylene) -5,5'-bibenzimidazole [poly (2,2'-m) -poly -phenylene) -5,5-bibenzimidazole] and poly (2,5-benzimidazole), sulfonated polysulfone, sulfonated polyether sulfone, sulfonated polyether ether sulfone, sulfonated polyarylene But are not limited to, ether sulfone, sulfonated polyether ketone, sulfonated polyether ether ketone, sulfonated polyimide, sulfonated polybenzimidazole, sulfonated polyphenylene oxide, sulfonated polydimethylphenylen oxide, Sulfonated polydiphenylphenylene oxide, brominated polyphenylene oxide sulphonic acid, brominated polydimethylphenylen oxide sulphonic acid, brominated polydiethylphenylene oxide sulphonic acid, brominated polydiphenylphenylene Oxidesulfonic acid, sulfonated At least one hydrogen ion selected from the group consisting of polyphenylene sulfide, sulfonated polystyrene, sulfonated polyurethane, naphion, polytrifluorostyrene sulfonic acid, polystyrene sulfonic acid and branched sulfonated polysulfone ketone copolymer Conductive polymer may be used. Particularly, a polymer obtained by grafting polystyrenesulfonic acid (PSSA) to a main chain of Nafion, Flemion, Ashiflex, and polytetrafluoroethylene (PTFE), a polyvinylidene difluoride (PVdF) A polymer obtained by grafting sulfonic acid (PSSA), a sulfonated polysulfone, a sulfonated polyarylene ether sulfone, a sulfonated polyether ether sulfone, a sulfonated polyether sulfone, a sulfonated polyimide, a sulfonated Sulfonated polyether ether ketone, sulfonated polyether ketone, sulfonated polyether ether ketone, sulfonated polyether ether ketone, sulfonated polyether ether ketone, Ether ketone ketones, sulfonated polystyrenes, sulfonated polyphenylene oxides, sulfonated polydimethylphenylen oxides, sulfonated polydiethylphenylene oxides, sulfonated polydiethers, It is preferably at least one selected from the group consisting of phenylphenylene oxide, brominated polyphenylene oxide sulfonic acid, brominated polydimethylphenylene oxide sulfonic acid, brominated polydiethylphenylene oxide sulfonic acid, and brominated polydiphenylphenylene oxide sulfonic acid .

The coating layer is formed on the impregnated layer, and comprises a fluoropolymer and nanoporous inorganic particles. That is, a dispersion liquid in which nano-porous inorganic particles are dispersed in a fluorine-based polymer solution is coated on the impregnated layer.

The fluoropolymer may be any of known fluoropolymers, but it is also possible to use a fluoropolymer composed of monomers of Nafion, Asiflex, Flemion, polyvinylidene fluoride, hexafluoropropylene, trifluoroethylene and polytetrafluoroethylene The number average molecular weight (Mn) is selected from the range of 1,000 to 1,000,000, and the weight average molecular weight (Mw) is preferably selected from the range of 10,000 to 1,000,000.

The nanoporous inorganic particles may be known inorganic particles having a nanoscale diameter. For example, pores may be formed in at least one material selected from the group consisting of silica, alumina, zirconia, zeolite, titanium and graphen oxide. Particularly, the -OH groups of the functional groups on the surface are partially substituted with -SO ₃ H groups As the particles, those having a pore diameter in the range of 0.1 to 100 nm can be used. That is, when particles having a pore diameter of more than 100 nm are used, not only vanadium ions are easily permeated but also bubbles are generated in the polymer electrolyte membrane to lower the stability, permeability, and durability of the membrane. When the particles are used, the cohesion between the particles becomes strong and the stability of the film may deteriorate.

The polymer electrolyte porous composite membrane of the present invention may have a thickness of 5 to 200 μm in a non-humidified state, and may be formed to have a thickness of 5 to 100 μm and a thickness of 10 to 50 μm.

Next, a method for producing a porous polymer composite membrane of the present invention comprises: preparing a porous support membrane; Forming an impregnated layer on the porous support membrane with the polymer solution for impregnation layer prepared; And forming a coating layer on the impregnated layer with a nanoparticle dispersion solution for a coating layer prepared.

The preparation of the porous support membrane may be carried out by preparing a known porous support membrane preparation method having a desired substance characteristic or by purchasing a commercial one and preparing the prepared porous support membrane by adding the prepared porous support membrane to an aqueous solution containing a mixture of alcohol, acetone, acetic acid, sulfuric acid, nitric acid, ≪ / RTI > washing with one or more solutions selected from the group consisting of < RTI ID = 0.0 >

The polymer solution for the impregnated layer used in the step of forming the impregnated layer can be prepared by using any well-known production method as a solution in which a sulfonated polymer and an amphiphilic polymer are uniformly dispersed in a solvent. For example, the polymer solution for the impregnated layer may be prepared at one time using a solvent capable of dispersing both the sulfonated polymer and the amphiphilic polymer, or may be prepared by mixing the sulfonated polymer solution in which the sulfonated polymer is dispersed and the parent The polymer solution may be prepared first, and then the sulfonated polymer solution and the amphiphilic polymer solution may be uniformly mixed. On the other hand, the step of forming the impregnated layer may include a step of impregnating the porous support membrane with the impregnated layer polymer solution, and diecasting the both surfaces of the impregnated porous support membrane.

The nanoparticle dispersion solution for coating layer used in the step of forming the coating layer can be prepared by using any known production method as a solution in which nanoporous inorganic particles are dispersed in a fluorinated polymer solution. Herein, the nanoporous inorganic particles are those in which -OH groups in the surface functional groups are partially replaced with -SO ₃ H groups, and the pore diameter of the particles may be 0.1 to 100 nm. The coating layer can be formed by any known method, for example, by coating a dispersion solution of a nano-particle for a coating layer on the impregnated layer and drying the coating layer.

When the impregnation layer and the coating layer are formed on the porous support membrane, the membrane can be dried under the following conditions. The primary drying may be carried out at a temperature of 30 to 60 ° C and then the secondary drying may be further carried out at a temperature of 50 to 140 ° C. This condition is to lower the probability of bubbles being generated in the impregnated layer and the coating layer. If bubbles are generated in the impregnated layer and the coating layer, the stability, permeability and durability of the film may be deteriorated.

The polymer electrolyte porous composite membrane of the present invention having such a structure may be applied to various fields, and may be an energy storage device such as a secondary battery including a redox flow battery or a fuel cell or a water treatment device.

Example 1

1. Porous support membrane preparation

Vacuum dried commercial PTFE porous support polymer having a pore size of 0.01 to 10 탆 was prepared, and then a pretreatment step was performed as follows. The prepared porous support membrane was placed in a mixed solution of alcohol and acetone, washed with ultrasonic waves, dried, immersed in a diluted sulfuric acid solution, washed with water, and then washed and dried in a mixed solution of alcohol and acetone.

2. Impregnation layer formation

(1) Preparation of polymer solution for impregnation layer

① Manufacture of urethane acrylate nonionomer (UAN), an amphipathic polymer

1 mol of polypropylene oxide triol and 3 mol of toluene dioxide (TDI) were reacted for 4 hours, and 2-HEMA was further introduced and reacted for 4 hours. Polyethylene glycol (PEG) Were synthesized.

② Manufacture of sulfonated polyphenylene oxide, a sulfonated polymer

2.4 g of PPO (polyphenylene oxide) prepared in a chloroform 78cc solvent was dissolved in a three-necked reactor for 30 minutes to prepare a precursor solution. 4.5 g of chlorosulfuric acid was slowly added to the solution while gradually stirring the reactor containing the prepared precursor solution. Min to the precursor solution in the reactor. The reactor in which the chlorosulfonic acid was added to the precursor solution was stirred at the maximum speed for 10 hours. After the stirring, the temperature of the reactor was maintained at 70 DEG C for 30 minutes. The reactants in the reactor were then washed twice more with distilled water. The precipitate generated in the washing process was filtered with a filter to separate the precipitate. The precipitate filtered with an excess of aqueous sodium hydroxide solution was added to the beaker and kept in ice water for 12 hours to synthesize the sulfonated polymer copolymer 1. The resulting sulfonated polymer copolymer 1 was added to distilled water and washed for 30 minutes. Thereafter, it was dried in a drying oven at 50 캜 for about 12 hours, and then dried in a vacuum oven at 70 캜 for 12 hours to obtain a sulfonated polyphenylene oxide having sulfonated polymer copolymer 1. At this time, the ion exchange capacity (IEC) representing the degree of sulfonation was 1.78.

③ Preparation of polymer solution for impregnation layer

1 g of sulfonated phenylene oxide (sPPO) is dissolved in 19 g of DMSO (Dimethylsulfoxide). 0.01 g of the prepared UAN was further dissolved to prepare a 5 wt% polymer solution for the impregnated layer.

④ Impregnation layer formation

The porous PTFE membrane was impregnated with the prepared impregnated polymer solution for 60 minutes and dried in a vacuum drier maintained at 40 degrees to impregnate the porous PTFE membrane with the sPPO solution to form an impregnated layer. The above procedure was repeated twice.

3. Coating Layer Formation

① Preparation of sulfonated porous silica particles as modified nanoporous inorganic particles

4 g of P123 (EO20PO70EO20; MW = 5800, Aldrich) was added to a 500 mL reactor, and 30 g of distilled water and 120 g of 2 M sulfuric acid were added to the reactor and stirred at 200 rpm until P123 was sufficiently dispersed. If P123 is not sufficiently dispersed in the aqueous solution, the silica to be produced in the present invention is uniformly dispersed, and therefore, it necessarily induces complete dispersion.

Thereafter, 10 g of TEOS (Tetra Ethyl Ortho Silicate, 98% Aldrich) was added and the temperature was maintained at 40 캜 in an oil bath. After adding TEOS, stir for about 1 hour to allow TEOS and P123 to form micelles, and then add MPTMS (3-mercaptopropyl) trimethoxysilane (95% Aldrich). The molar ratio of TEOS: MPTMS = 9: 1 was used as the molar ratio of MPTMS to TEOS.

All the reactants were mixed and reacted with mechanical stirring at 40 ° C for 20 hours, and the reactor was kept at 100 ° C for 24 hours in a sealed state. Upon completion of the reaction, a solid product was formed. The resulting solid product was filtered through a filter and dried at 100 ° C for 24 hours. When drying was completed, the solid product was placed in a container containing ethanol and washed with a stirrer for 4 hours. After washing for 4 hours, it was sufficiently dried to remove all of the ethanol, and the remaining P123 was removed by heat treatment at 500 ° C. If the temperature is raised without drying, all the solid product may be carbonized. Therefore, the weight before drying and the weight after drying should be dried until the weight is no longer reduced. P123 is removed through heating due to the end of the dispersing agent.

The weight of the removed product was measured up to P123, and the surface sulfonated silica was obtained by oxidizing it with 10 g of 30 wt% H ₂ O ₂ aqueous solution per 0.3 g of product mass for 24 hours at room temperature. This material was washed several times with water and ethanol, and then dried at 100 ° C for 24 hours to obtain sulfonated porous silica particles.

② Manufacture of Nafion solution, a fluorine-based polymer

The fluorochemical polymer solution was prepared by dissolving recast Nafion obtained by casting a commercial Nafion solution, which is a fluoropolymer, into a polar solvent at a concentration of 10 wt%.

③ Preparation of polymer solution for coating

A polymer solution for coating was prepared by mixing 3 wt% of sulfonated silica with 97 wt% of a fluorinated polymer solution.

④ Coating Layer Formation

The porous impregnated membrane impregnated with sPPO and UAN solution was coated with Nafion solution in which sulfonated silica was dispersed and dried to form a coating layer on the impregnated layer.

4. Polymer Electrolyte Porous Composite Membrane Formation

After the coating layer was formed, it was dried in an oven at 50 ° C. for 24 hours, and then impregnated with distilled water to obtain a composite membrane precursor. The composite membrane precursor thus obtained was heated at 40 ° C. at a rate of 10 ° C./hr to 130 ° C., And dried to obtain a polymer electrolyte porous composite membrane 1.

Example 2

The polyelectrolyte porous composite membrane 2 was obtained in the same manner as in Example 1, except that a polyvinylidene difluoride (PVdF) membrane prepared by the following method was used as the porous support membrane.

PVdF was dissolved in a DMF solvent at a concentration of 15% and cast on a glass plate with a doctor blade. After partial removal of the solvent for 1 to 4 minutes in a 90 ° oven, the solution is dipped in a DI water bath for cost-effective production. After 6 hours, the PVdF membrane was washed with a methanol solution and dried to remove the residual solvent, thereby preparing a porous PVdF membrane.

Example 3

A polymer electrolyte porous composite membrane 3 was obtained in the same manner as in Example 1, except that a poly phenylene oxide (PPO) membrane prepared by the following method was used as the porous support membrane.

PPO was dissolved in a chloroform solvent at a concentration of 15% and cast on a glass plate with a doctor blade. After partial removal of the solvent for 1 to 4 minutes in a 90 ° oven, the solution is dipped in a DI water bath for cost-effective production. After 6 hours, the PPO membrane was washed with a methanol solution and dried to remove the residual solvent, thereby preparing a porous PPO membrane.

Comparative Example

Sulfuric acid solution, aqueous hydrogen peroxide solution, and distilled water.

Experimental Example 1

The results of SEM analysis of the surface morphology of the porous support membrane obtained in Example 1 and the cross-sectional morphology of the polymer electrolyte porous composite membrane 1 are shown in FIGS. 1, 2 and 3, respectively.

1, pores having a size of several mu m formed on the surface of the porous Teflon polymer membrane as the porous support membrane can be confirmed.

2 and 3, the surface and cross section of the polymer electrolyte porous composite membrane 1 having the impregnated layer and the coating layer formed on the porous Teflon polymer membrane can be observed. As shown in the figure, the impregnation layer and the coating layer completely fill the pores of the porous support membrane.

Experimental Example 2

The water content, the dimensional change, the proton conductivity, the vanadium permeability and the reduction ratio were measured for the polymer electrolyte membrane porous composite membranes 1 to 3 obtained in Examples 1 to 3 and the comparative membrane obtained in Comparative Example. Respectively. Moisture content and dimensional change ratio were calculated based on weight and size ratio before and after humidification. The hydrogen ion conductivity was measured by impedance spectroscopy. Impedance measurement conditions were set in the range of 1 Hz to 1 MHz and were measured in an in-plane manner. All experiments were performed in a state where the sample was completely humidified . The vanadium reduction rate for the durability test was determined by measuring the amount of V5 + reduced to V4 + by UV-VIS by immersing the ion exchange membrane in 0.1M V5 +, 5M H2SO4 solution at 40 ℃ and sampling the solution over time.

division Humidity
(% at RT) Dimensional change rate
(% at RT) Hydrogen ion conductivity (S / cm at RT) Vanadium permeability
(m ² / s at RT) Fenton test remaining (1hr) Porous
Composite membrane 1 13 6 0.013 0.9x10 ^-11 0.0010 Porous
Composite membrane 2 14 8 0.011 0.9x10 ^-11 0.0012 Porous
Composite membrane 3 16 11 0.012 1.0x10 ^-11 0.0015 Comparative Example Film 25 15 0.071 2.5x10 ^-11 0.0015

It can be seen from Table 1 that the polymer electrolyte porous composite membrane of the present invention has at least the same or substantially superior characteristics in terms of water content, dimensional change rate, proton conductivity, vanadium permeability, and reduction ratio as compared with a commercially available nafion membrane Able to know.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (20)

A porous support membrane;
An impregnation layer formed by surrounding the porous support membrane; And
And a coating layer formed on the impregnated layer,
Wherein the impregnated layer comprises a sulfonated polymer and an amphiphilic polymer.
The method according to claim 1,
The porous support film may be formed of at least one of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polyphenylene oxide (PPO), polybenzimidazole (PBI), polyimide (PI), polyvinylidene fluoride Wherein the polymer electrolyte comprises at least one polymer material selected from the group consisting of polyvinylidene fluoride (PVdF), polyvinyl chloride (PVC), or copolymerized polymers obtained by polymerizing monomers thereof, and has pores having a diameter of 10 nm or more. membrane.
delete The method according to claim 1,
The sulfonated polymer may be a polymer obtained by grafting polystyrene sulfonic acid (PSSA) to the main chain of Nafion, Flemion, Asiflex, polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVdF) A polymer obtained by grafting polystyrenesulfonic acid (PSSA), a sulfonated polysulfone, a sulfonated polyarylene ether sulfone, a sulfonated polyether ether sulfone, a sulfonated polyether sulfone, a sulfonated polyimide , Sulfonated polyimidazoles, sulfonated polybenzimidazoles, sulfonated polyether benzimidazoles, sulfonated polyarylene ether ketones, sulfonated polyether ether ketones, sulfonated polyether ketones, alcohols Sulfonated polyphenylene oxide, sulfonated polyetherketone ketone, sulfonated polystyrene, sulfonated polyphenylene oxide, sulfonated polydimethylphenylen oxide, sulfonated polydiethylphenylene oxide, sulphonated polydimethylphenylene oxide, And at least one member selected from the group consisting of polyphenylene oxide, polyphenylphenylene oxide, polyphenylphenylene oxide, brominated polyphenylene oxide sulfonic acid, brominated polydimethylphenylene oxide sulfonic acid, brominated polydiethylphenylene oxide sulfonic acid and brominated polydiphenylphenylene oxide sulfonic acid Wherein the polymer electrolyte membrane is a porous membrane.
The method according to claim 1,
Wherein the amphiphilic polymer has at least one hydrophilic segment having a hydroxyl group and a hydrophobic segment at the same time.
The method according to claim 1,
Wherein the sulfonated polymer has a number average molecular weight (Mn) of 1,000 to 1,000,000 and a weight average molecular weight (Mw) of 10,000 to 1,000,000.
A porous support membrane;
An impregnation layer formed by surrounding the porous support membrane; And
And a coating layer formed on the impregnated layer,
Wherein the coating layer comprises a fluoropolymer and nanoporous inorganic particles.
8. The method of claim 7,
Wherein the nanoporous inorganic particles have pores formed in at least one material selected from the group consisting of silica, alumina, zirconia, zeolite, titanium, and graphen oxide.
8. The method of claim 7,
Wherein the nanoporous inorganic particles have a -OH group in the functional groups of the surface partly substituted with -SO ₃ H groups, and the pore diameter of the particles is 0.1 to 100 nm.
8. The method of claim 7,
Wherein the fluorine-based polymer is at least one selected from the group consisting of Nafion, Asiflex, Flemion, polyvinylidene fluoride, hexafluoropropylene, trifluoroethylene and polytetrafluoroethylene. Composite membrane.
The method according to claim 1,
Wherein the polymer electrolyte porous composite membrane has a thickness of 5 to 500 mu m in a non-humidified state.
Preparing a porous support membrane;
Forming an impregnated layer on the porous support membrane with the polymer solution for impregnation layer prepared; And
And forming a coating layer on the impregnated layer with a nanoparticle dispersion solution for a coating layer prepared on the impregnated layer.
13. The method of claim 12,
Wherein the step of preparing the porous support membrane comprises a pretreatment step of washing the porous support membrane with at least one solution selected from the group consisting of alcohol, acetone, acetic acid, sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, hydrogen peroxide solution (Method for manufacturing electrolyte porous composite membrane).
13. The method of claim 12,
Wherein the polymer solution for the impregnated layer is prepared by uniformly dispersing a sulfonated polymer and an amphiphilic polymer in a solvent.
13. The method of claim 12,
Wherein the step of forming the impregnated layer comprises impregnating the porous support membrane with the impregnated layer polymer solution and diecasting the both surfaces of the impregnated porous support membrane.
13. The method of claim 12,
Wherein the nanoparticle dispersion solution for a coating layer comprises nanoporous inorganic particles dispersed in a fluorinated polymer solution.
17. The method of claim 16,
Wherein the nanoporous inorganic particles have a -OH group in the functional groups of the surface partially substituted with -SO ₃ H groups, and the pore diameter of the particles is 0.1 to 100 nm.
A polymer electrolyte porous composite membrane according to any one of claims 1, 2, 4 to 11 or a polymer electrolyte porous composite membrane prepared by the manufacturing method according to any one of claims 12 to 17, Device.
19. The method of claim 18,
Wherein the energy storage device is a secondary battery or a fuel cell.
A water treatment apparatus comprising a polymer electrolyte porous composite membrane according to any one of claims 1, 2, 4 to 11 or a polymer electrolyte porous composite membrane manufactured by a manufacturing method according to any one of claims 12 to 17 .

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