KR20180037498A - Polymer and membrane comprising same - Google Patents

Abstract

The present invention relates to a polymer including at least two main chains linked by a bridge structure of a chemical formula (1), a polymer electrolyte membrane and a reinforcing membrane containing a polymer, a polymer electrolyte fuel cell including the same, and a redox flow battery. According to embodiments of the present invention, the polymer has improved mechanical strength and durability due to the bridge structure.

Description

[0001] POLYMER AND MEMBRANE COMPRISING SAME [0002]

The present disclosure relates to polymers and membranes comprising them. More specifically, the present specification relates to a partially fluorinated polymer and a polymer electrolyte membrane or a reinforced membrane comprising the same. The present invention also relates to a fuel cell or a redox flow battery comprising the polymer electrolyte membrane or the reinforcement membrane.

Fuel cells are energy conversion devices that convert the chemical energy of a fuel directly into electrical energy. That is, a fuel cell uses a fuel gas and an oxidizing agent, and generates electricity using electrons generated during the oxidation-reduction reaction. The membrane electrode assembly (MEA) of a fuel cell is composed of a cathode, an anode, and an electrolyte membrane, that is, an ion conductive electrolyte membrane, as a portion where an electrochemical reaction of hydrogen and oxygen takes place.

Redox Flow Battery (Redox Flow Battery) is a system in which an active substance contained in an electrolyte is oxidized and reduced to be charged and discharged. An electrochemical storage device that stores chemical energy of an active substance directly as electric energy to be. The unit cell of the redox flow battery includes an electrode, an electrolyte, and an ion exchange membrane (electrolyte membrane).

Fuel cells and redox flow cells are being researched and developed as a next generation energy source because of their high energy efficiency and eco - friendly characteristics with low emission of pollutants.

The most important components of the fuel cell and the redox flow cell are cation exchange polymer electrolyte membranes, which are: 1) excellent proton conductivity 2) cross-over of the electrolyte 3) strong chemical resistance 4) mechanical Physical properties and / or 4) low swelling ratio. The polymer electrolyte membrane is classified into a fluorine system, a partial fluorine system, and a hydrocarbon system. In the case of a partially fluorinated polymer electrolyte membrane, the polymer electrolyte membrane has an excellent physical and chemical stability and a high thermal stability due to its fluorine main chain. Also, like the fluorinated polymer electrolyte membrane, the partial fluorinated polymer electrolyte membrane has the advantages of the hydrocarbon-based polymer electrolyte membrane and the fluorinated polymer electrolyte membrane because the cation-transfer functional group is attached to the end of the fluorinated chain.

 [Prior Art Literature]

[Patent Literature]

Korean Laid-Open Publication No. 2003-0076057

The present application is intended to provide a partially fluorinated polymer having a novel structure, a polymer electrolyte membrane and a reinforcing membrane containing the same, a fuel cell and a redox flow battery including the same.

One embodiment of the present disclosure provides a polymer comprising two or more backbones linked by a bridging structure of formula 1:

[Chemical Formula 1]

In Formula 1,

R 1 to R 4 are the same or different and are each independently a halogen group,

D 1 and D 2 are the same or different and are each independently S, O, SO ₂ or NH,

a and b are each an integer of 2 to 20, the structures in parentheses are the same or different from each other,

는 중합체 내의 주쇄에 연결되는 부위이다.

Is a site connected to the main chain in the polymer.

Another embodiment of the present invention provides a polymer electrolyte membrane comprising the polymer.

Another embodiment of the present disclosure provides a reinforced membrane comprising the polymer. Here, the reinforcing film may be a substrate; And the polymer.

Another embodiment of the present disclosure is directed to an anode; Cathode; And the above-described polymer electrolyte membrane provided between the anode and the cathode.

Another embodiment of the present disclosure is directed to an anode; Cathode; And the above-described reinforcing membrane provided between the anode and the cathode.

Another embodiment of the present disclosure includes at least two of the above-described membrane-electrode assemblies; A stack including a bipolar plate disposed between the membrane-electrode assemblies; A fuel supply unit for supplying fuel to the stack; And an oxidant supply unit for supplying an oxidant to the stack.

The present invention also relates to a positive electrode comprising a positive electrode and a positive electrode electrolyte; A negative electrode cell comprising a negative electrode and a negative electrode electrolyte; And a polymer electrolyte membrane provided between the anode cell and the cathode cell.

Finally, the present specification discloses a positive electrode comprising a positive electrode and a positive electrode electrolyte; A negative electrode cell comprising a negative electrode and a negative electrode electrolyte; And a reinforcement film provided between the positive electrode cell and the negative electrode cell.

Polymers according to the embodiments described herein have improved mechanical strength and durability due to the crosslinked structure. Particularly, it is advantageous that a polymer having a site at the 2,4-position connected to the main chain based on the partial fluorinated pendant is produced in a high molecular weight. In this case, although the main chain is broken, the mechanical strength and durability Can be improved. Also, the disulfonamide between the halogen groups such as the fluorine group has a high acidity and can act not only as a crosslinking structure, but also as an acid for transferring the proton. In addition, even when the main chain has a low molecular weight, it can be made into a polymer having a high molecular weight by a crosslinked structure, and thereby a polymer favorable for the casting process can be obtained.

1 is a schematic view showing an electricity generation principle of a fuel cell.
2 is a schematic view showing an embodiment of a redox flow battery.
3 is a schematic view showing one embodiment of a fuel cell.
4 is a photograph showing the state of the polymer prepared in Examples 1 and 2 before crosslinking and after crosslinking.
5 shows the IR data of the polymers prepared in Examples 1 and 2. FIG.

The polymer according to one embodiment of the present invention comprises two or more main chains connected by the crosslinking structure of the above-mentioned formula (1).

The cross-linking structure of Formula 1 includes a bis-sulfonimide group (-SO ₂ NHSO ₂ -) structure, which has an electron-attracting effect of a sulfone group (SO ₂ ). Between the structure of a bis sulfone imide group-Thus, sulfonic Ponca the imide group (-SO ₂ NHCO-), and bis carbon is a bis sulfone than the mid (-CONHCO-) imide group (-SO ₂ NHSO ₂₎ NH can exhibit stronger acidity.

The acidity of acidity is also affected by the functional groups bonded to both sulfone groups (SO ₂ ), with the bissulfoneimide group as a center. Even when a bis-sulfonimide group is present between aromatic or aliphatic hydrocarbon-based structures, it shows acidity, but its acidity is very small, indicating weak acidity. Especially the acidity of the bissulfoneimide groups between the aromatic structures is very low. On the other hand, when a fluorine-based functional group having a high electronegativity is located on both sides, the acidity of the bis-sulfonimide group can be greatly increased and act as a strong acid. Therefore, in the case of a partial fluorinated pendant such as a crosslinked structure of the above-mentioned formula (1) wherein R1 to R4 are halogen groups, as compared with the polymer consisting only of a hydrocarbon chain, the bissulfoneimide group present between the halogen groups acts as a strong acid The acidity is high.

Thus, when the polymer is used as an ion-exchange membrane, not only the membrane durability due to the crosslinked structure is greatly improved, but also the structure of the bis-sulfone imide group (-SO ₂ NHSO ₂ -) having high acidity and the Due to the presence of bissulfoneimide, the cation conductivity is also high, which can contribute to the improvement of fuel cell efficiency.

The polymer according to another embodiment of the present disclosure comprises units of the following formula (2).

(2)

In Formula 2,

B 1 to B 4 are the same or different from each other, and are each independently S, O or SO ₂ ,

G1 and G2 are the same as or different from each other, and are each independently selected from O, S, SO _2, CO or CF _2,

c, d, p, q, r and s are each 0 or 1,

R1 to R4, D1 and D2 are as defined in formula (1).

According to one embodiment of the present invention, the formula (2) may be represented by the following formula (3).

(3)

In the general formula (3), the substituents are as described above.

According to one embodiment of the present invention, the polymer may comprise 1 mol% to 100 mol% of the units of the above formula (2) or (3) based on the total of the repeating units constituting the polymer. Units may be contained in an amount of 5 mol% to 65 mol%.

According to another embodiment of the present invention, the polymer may further include units other than the units of the general formula (2) or (3).

According to one embodiment of the present disclosure, the polymer comprising units of the general formula (2) or (3) may further comprise a unit capable of controlling ionic conductivity of the membrane containing the polymer. For example, the polymer containing units of the above formula (2) or (3) further includes a unit represented by the following formula (4).

[Chemical Formula 4]

In Formula 4,

And B5 and B6 are the same as or different from each other, each independently S, O or SO _2,

G3 is O, S, SO _2, and CO ₂ or CF,

e, t and u are each 0 or 1,

D3 is S, O, SO ₂ or NH,

L is a divalent group containing at least one fluorine, for example, - (CRR ') w-, R and R' are the same or different from each other, each independently a halogen group, and w is an integer from 2 to 20; According to one example, R and R 'are fluorine groups.

Since the functional group containing a partial fluorine group is extended in the form of a pendant, the unit of the general formula (4) can be easily separated from the partial fluorine functional groups in the polymer. Therefore, the ion channel can be easily formed, and ions can be selectively exchanged, so that the ion conductivity of the separation membrane can be improved.

In one embodiment of the present invention, when the polymer further comprises the unit of the formula (4), the content thereof may be 1 to 100, based on the unit of the formula (2) or (3). For example, when the unit of Formula 4 is 100 units based on one unit of Formula 2 or 3, 1% of the hydrophilic part is cross-linked. For example, the unit of the formula (2) or (3) may be 1 to 10% of the hydrophilic units constituting the polymer.

According to one embodiment of the present invention, the polymer comprising units of the above formula (2) or (3) further comprises units of the following formula (5).

[Chemical Formula 5]

In Formula 5,

A1 is a carbonyl group, a sulfonyl group or a sulfide group,

B7 is S, O or SO _2,

x is 0 or 1;

In one embodiment of the present invention, when the polymer further comprises a unit represented by the above formula (5), its content may be 1 to 100, based on one unit of the above formula (2) or (3). For example, the unit of the formula (2) or (3) may be present in an amount of 1 to 10% based on 100% of the unit of the formula (2) or the unit of the formula (5).

According to one embodiment of the present invention, the formula (1) may be represented by the following formula (1-1).

[Formula 1-1]

As described above, when it is connected to the main chain in the polymer through the 2,4-carbon position of the benzene of the formula (1-1), the reactivity can be remarkably improved in the polymerization reaction and not only a high molecular weight resin can be obtained, , The durability is improved by the crosslinked structure.

According to another embodiment of the present invention, the formula (2) may be represented by the following formula (2A).

(2A)

According to another embodiment of the present invention, the formula (3) may be represented by the following formula (3A).

[Chemical Formula 3]

According to another embodiment of the present invention, the formula (3) may be represented by one of the following formulas (3-1) to (3-3).

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

According to another embodiment of the present invention, the formula (3) may be represented by the following formula (3-4).

[Chemical Formula 3-4]

According to another embodiment of the present invention, the formula (4) may be represented by the following formula (4A).

[Chemical Formula 4A]

According to another embodiment of the present invention, the formula (4) may be represented by the following formula (4-1) or (4-2).

[Formula 4-1]

[Formula 4-2]

According to another embodiment of the present invention, the formula (4) may be represented by the following formula (4-3).

[Formula 4-3]

According to one embodiment of the present disclosure, R 1 to R 4 are fluorine groups.

According to one embodiment of the present disclosure, a and b are 2 to 10, preferably 2 to 6.

According to one embodiment of the present disclosure, D1 and D2 are S or O. Partially fluorinated pendants having S or O as linkers (D1, D2) all have an ionic conductivity improved by increasing the acidity of the sulfonic acid at the end due to the influence of fluorine and having a form in which the sulfonic acid is separated from the polymer main chain The phase separation can be more efficiently performed and the separation membrane performance can be improved. In particular, when applied to an MEA (membrane electrode assembly), a high ionic conductivity is exhibited even under low humidification conditions, and ultimately the cell efficiency can be greatly improved.

According to one example, D1 and D2 in the aforementioned formulas 3-1 to 3-3 are S. When D1 and D2 are S, the whole part fluorinated pendant shows an electron withdrawing effect due to the fluorine of the partial fluorine system. Therefore, when the polymer is synthesized by using the monomer, it is confirmed that the 2,4 position has better reactivity Respectively.

According to another example, D1 and D2 in formula (3-4) are O. When D1 and D2 were O, the electron donating effect was large owing to the effect of O, and it was confirmed that the fluorine at the 3,5 position was more effective in the polymerization reaction. When D1 and D2 are O, they are advantageous from the viewpoint of thermal denaturation of the separator.

According to an exemplary embodiment of the present disclosure, a B1 to B4 is O, S or SO _2. When B1 to B4 are S, they can be converted to SO2 using a polymer post reaction, such as an oxidation reaction.

According to one embodiment of the present disclosure, p, q, r, and s are one.

According to one embodiment of the present disclosure, D3 is S or O. According to one example, in the above-described formula 4-1 or 4-2, D3 is S. According to another example, in the above formula 4-3, D3 is O. The contents related to D1 and D2 described above can also be applied to D3.

According to an exemplary embodiment of the present disclosure, a B5 and B6 is O, S or SO _2.

According to one embodiment of the present disclosure, t and u are one.

According to one embodiment of the present disclosure, A1 is a sulfonyl group or a carbonyl group.

According to an exemplary embodiment of the disclosure, B7 is O, S or SO _2.

The polymer comprising two or more main chains connected by the crosslinking structure of the above-mentioned formula (1) may be obtained by introducing a halogen group such as Cl instead of H of SO3H of the polymer containing the unit of the above-mentioned formula (4) and the unit of the above- In the presence of a solvent, with an amine compound such as ammonium chloride, triethylamine, and the like.

According to one example, the above-described polymer can be prepared as shown in the following reaction formula.

[Reaction Scheme]

Here, l, n and m mean the content ratio of structures in parentheses, and m: n or m: can be 1: 1 to 1: 100.

In one embodiment of the present disclosure, the polymer may be a random polymer, which may comprise a hydrophilic unit and a hydrophobic unit. At this time, the hydrophilic unit may include the crosslinked structure of the above-mentioned formula (1). The hydrophilic unit means a unit having an ion-exchange group as a functional group.

In another embodiment of the present disclosure, the polymer comprises a hydrophilic block; And a block polymer comprising a hydrophobic block. The hydrophilic block may include the crosslinked structure of the above-mentioned formula (1). In the present specification, the block polymer means a polymer composed of one block and one or more blocks different from the block connected to each other through the main chain of the polymer.

The hydrophilic block is a block made up of hydrophilic units as a functional group, and means a block having an ion-exchange group. The above-mentioned "block having an ion-exchange group" means a block represented by the number of ion-exchange groups per one structural unit constituting the block and an average of at least 0.5 or more blocks per one structural unit. It is more desirable to have an exchange. The ion exchange group is ^{_{-SO 3 H, -SO 3 - M}} +, -COOH, -COO - M +, -PO 3 H 2, -PO 3 H - M +, -PO 3 2- 2M +, _{-O (CF 2) m SO 3} H, -O (CF 2) m SO 3 - M +, -O (CF 2) m COOH, -O (CF 2) m COO - M +, -O (CF 2 ) _m PO ₃ H ₂ , -O (CF ₂ ) _m PO ₃ H ^- M ⁺ and -O (CF ₂ ) _m PO ₃ ^{2 -} 2M ⁺ , wherein M is at least one selected from the group consisting of metallic It can be an element.

The hydrophobic block in the present specification means a block made of hydrophobic units, and the polymer block having substantially no ion exchanger. The above-mentioned "block having substantially no ion-exchanger" means a block having an average of less than 0.1 in terms of the number of ion-exchange groups per structural unit constituting the block, more preferably 0.05 or less, It is more preferable that the block has no ion exchanger.

According to the embodiment of the present invention, in the case of a block polymer, separation of the hydrophilic block and the hydrophobic block is clearly distinguished, so that phase separation is easy and ion transfer can be facilitated.

In one embodiment of the present disclosure, the hydrophilic unit and the hydrophobic unit are contained in the polymer in a molar ratio of 1: 0.1 to 1:10. In one embodiment of the present invention, the hydrophilic unit and the hydrophobic unit are contained in the polymer in a ratio of 1: 0.1 to 1: 2. In this case, the ion transfer ability of the polymer can be increased.

The unit of the above-mentioned formula (4) may constitute a hydrophilic unit, and the unit of the above-mentioned formula (5) may constitute a hydrophobic unit.

In one embodiment of the present disclosure, the number average molecular weight of the hydrophilic block is from 1,000 g / mol to 300,000 g / mol. In a specific embodiment, from 2,000 g / mol to 100,000 g / mol. And in another embodiment from 2,500 g / mol to 50,000 g / mol.

In one embodiment of the present disclosure, the number average molecular weight of the hydrophobic block is from 1,000 g / mol to 300,000 g / mol. In a specific embodiment, from 2,000 g / mol to 100,000 g / mol. And in another embodiment from 2,500 g / mol to 50,000 g / mol.

In one embodiment of the present disclosure, the weight average molecular weight of the polymer is from 5,000 g / mol to 10,000,000 g / mol. When the weight average molecular weight of the polymer is within the above range, the mechanical properties of the electrolyte membrane including the polymer are not lowered, the solubility of the polymer is maintained, and the polymer electrolyte membrane can be applied to the casting process. have.

The present specification also provides a polymer electrolyte membrane comprising the above-mentioned polymer.

As used herein, the term "electrolyte membrane" is a membrane capable of ion exchange, and includes a membrane, an ion exchange membrane, an ion transport membrane, an ion conductive membrane, a membrane, an ion exchange membrane, A transfer electrolyte membrane, an ion conductive electrolyte membrane, and the like.

The polymer electrolyte membrane according to one embodiment of the present invention can be produced using materials and / or methods known in the art, except that the polymer electrolyte membrane includes a polymer having a crosslinked structure of the above formula (1).

According to one embodiment of the present invention, the ionic conductivity of the polymer electrolyte membrane is from 0.01 S / cm to 0.5 S / cm. In another embodiment, the ionic conductivity of the polymer electrolyte membrane is 0.01 S / cm or more and 0.3 S / cm or less.

In one embodiment of the present invention, the ionic conductivity of the polymer electrolyte membrane can be measured under a humidifying condition. In the present specification, the humidifying condition may mean a relative humidity (RH) of 10% to 100%.

In one embodiment of the present invention, the ion exchange capacity (IEC) value of the polymer electrolyte membrane is 0.01 mmol / g to 5 mmol / g. When the ion exchange capacity value is in the range, the ion channel in the polymer electrolyte membrane is formed, and the polymer can exhibit ion conductivity.

In one embodiment of the present invention, the thickness of the polymer electrolyte membrane is 1 탆 to 500 탆. The polymer electrolyte membrane having the above-described range of thickness can lower the electric short and the crossover of the electrolyte material and exhibit excellent cation conductivity.

In one embodiment of the present disclosure, a substrate; And a reinforcing film comprising the above polymer.

In one embodiment of the present disclosure, the 'reinforcing membrane' is an electrolyte membrane including a base material which is a reinforcing material, and includes an ion exchangeable membrane including a membrane including a substrate, an ion exchange membrane, an ion transport membrane, An ion exchange membrane, an ion exchange membrane, an ion exchange membrane, an ion exchange membrane, an ion exchange membrane, an ion exchange membrane, an ion exchange electrolyte membrane, an ion transfer electrolyte membrane or an ion conductive electrolyte membrane.

As used herein, the substrate may refer to a support of a three-dimensional network structure, wherein the reinforcing membrane comprising the substrate and the polymer is such that the polymer has one surface of the substrate, a surface opposite the one surface, The present invention is not limited thereto. That is, the reinforcing membrane of the present specification may be provided in a form impregnated with the polymer.

In the case of the hydrocarbon-based ion-transfer membrane, the ion-transporting ability is lower than that of the fluorine-based membrane, and the chemical resistance is poor. Accordingly, the reinforced membrane according to one embodiment of the present invention has a high mechanical strength and a high ionic conductivity by including the polymer having the crosslinking structure and the partial fluorine-containing unit represented by the general formula (4) . ≪ / RTI >

In addition, the reinforcing film according to one embodiment of the present invention can improve the chemical resistance and durability of the device including the substrate, thereby improving the lifetime of the device.

In one embodiment of the present disclosure, the substrate is one or two kinds of materials selected from the group consisting of polypropylene (PP), polytetrafluoroethylene (PTFE), polyethylene (PE), and polyvinylidene difluoride Is selected.

In one embodiment of the present invention, the content of the polymer relative to 100 parts by weight of the reinforcing membrane is 10 parts by weight to 99 parts by weight.

In another embodiment, the content of the polymer is 10 parts by weight to 99 parts by weight with respect to 100 parts by weight of the reinforcing membrane, and the content of the base is 1 part by weight to 90 parts by weight. As the content of the base material increases, crossover of the vanadium ion can be reduced. As the content of the polymer increases, the performance of the battery can be improved.

Therefore, when the content of the substrate and the polymer according to one embodiment of the present invention is within the above range, the performance of the battery can be maintained and crossover of the vanadium ion can be reduced.

 According to one embodiment of the present invention, the ionic conductivity of the reinforcement film is 0.001 S / cm or more and 0.5 S / cm or less. In another embodiment, the ionic conductivity of the reinforcement film is 0.001 S / cm or more and 0.3 S / cm or less.

In the present specification, the ionic conductivity can be measured under the same conditions as the above-mentioned method.

Also, in one embodiment of the present disclosure, the ion exchange capacity (IEC) value of the reinforced membrane is from 0.01 mmol / g to 5.0 mmol / g. When the ion exchange capacity value is in the range, the ion channel in the reinforcing membrane is formed, and the polymer can exhibit ion conductivity.

In one embodiment of the present invention, the thickness of the reinforcing film is from 0.01 m to 10,000 m. The reinforced membrane having the above-mentioned range of thickness can lower the electric short and the crossover of the electrolytic material and can exhibit excellent cation conductivity characteristics.

The disclosure also relates to a method of manufacturing a substrate, comprising: preparing a substrate; And impregnating the substrate with the polymer.

In this specification, impregnation means that the polymer penetrates into the substrate. In the present specification, the impregnation may be performed by dipping the substrate into the polymer, slot dye coating, bar casting, or the like.

In this specification, the immersion may be expressed by terms such as dip coating or dipping method.

In one embodiment of the present disclosure, the reinforcing membrane may be oriented. Specifically, in one embodiment of the present specification, the substrate may be produced by uniaxial stretching or biaxial stretching, and the orientation of the substrate by the stretching may determine the orientation of the reinforcing film. Therefore, the reinforcing membrane according to one embodiment of the present disclosure can have a machine direction (MD) and a machine direction (MD) directional directionality, and the reinforcing membrane has stress and elongation The physical properties of the polymer can be different.

The disclosure also relates to a method of manufacturing a substrate, comprising: preparing a substrate; And immersing the substrate in the polymer.

The disclosure also includes an anode; Cathode; And the above-described polymer electrolyte membrane provided between the anode and the cathode.

The disclosure also includes an anode; Cathode; And the above-described reinforcing membrane provided between the anode and the cathode.

The membrane-electrode assembly (MEA) means a junction body of an electrode (cathode and anode) where an electrochemical catalytic reaction of fuel and air takes place and a polymer membrane in which hydrogen ions are transferred, and the electrode (cathode and anode) It is a single integral unit.

The membrane-electrode assembly of the present invention can be produced by a conventional method known in the art, such that the catalyst layer of the anode and the catalyst layer of the cathode are in contact with the electrolyte membrane. For example, the cathode; Anode; And an electrolyte membrane positioned between the cathode and the anode in close contact with each other at 100 ° C to 400 ° C.

The anode electrode may include an anode catalyst layer and an anode gas diffusion layer. The anode gas diffusion layer may again include an anode microporous layer and an anode electrode substrate.

The cathode electrode may include a cathode catalyst layer and a cathode gas diffusion layer. The cathode gas diffusion layer may again include a cathode microporous layer and a cathode electrode substrate.

FIG. 1 schematically shows an electricity generating principle of a fuel cell. In a fuel cell, a basic unit for generating electricity is a membrane electrode assembly (MEA), which includes an electrolyte membrane 100 and an electrolyte membrane 100, And an anode 200a and a cathode 200b electrodes formed on both sides of the cathode 200a. 1 showing the principle of electricity generation of a fuel cell, in the anode 200a, oxidation reaction of hydrogen such as hydrogen or hydrocarbons such as methanol and butane occurs, hydrogen ions (H +) and electrons (e-) are generated, The hydrogen ions move through the electrolyte membrane 100 to the cathode 200b. In the cathode 200b, hydrogen ions transferred through the electrolyte membrane 100 react with an oxidizing agent such as oxygen and electrons to generate water. This reaction causes electrons to migrate to the external circuit.

The catalyst layer of the anode electrode is preferably a catalyst selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloy, platinum-osmium alloy, platinum-palladium alloy and platinum- Lt; / RTI > The catalyst layer of the cathode electrode is a place where a reduction reaction of an oxidizing agent occurs, and a platinum or platinum-transition metal alloy can be preferably used as a catalyst. The catalysts can be used not only by themselves but also by being supported on a carbon-based carrier.

The process of introducing the catalyst layer can be performed by a conventional method known in the art. For example, the catalyst ink may be directly coated on the electrolyte membrane or coated on the gas diffusion layer to form the catalyst layer. The method of coating the catalyst ink is not particularly limited, but spray coating, tape casting, screen printing, blade coating, die coating or spin coating may be used. The catalyst ink may typically consist of a catalyst, a polymer ionomer and a solvent.

The gas diffusion layer serves as a current conductor and serves as a passage for reacting gas and water, and has a porous structure. Therefore, the gas diffusion layer may include a conductive base material. As the conductive substrate, carbon paper, carbon cloth or carbon felt can be preferably used. The gas diffusion layer may further include a microporous layer between the catalyst layer and the conductive base. The microporous layer can be used to improve the performance of the fuel cell under low humidification conditions and serves to reduce the amount of water flowing out of the gas diffusion layer to make the electrolyte membrane sufficiently wet.

One embodiment of the present disclosure includes at least two membrane-electrode assemblies; A stack including a bipolar plate disposed between the membrane-electrode assemblies; A fuel supply unit for supplying fuel to the stack; And an oxidant supply unit for supplying an oxidant to the stack.

In this specification, the membrane-electrode assembly includes the above-described polymer electrolyte membrane or includes a reinforcing membrane.

Fuel cells are energy conversion devices that convert the chemical energy of a fuel directly into electrical energy. That is, a fuel cell uses a fuel gas and an oxidizing agent, and generates electricity using electrons generated during the oxidation-reduction reaction.

The fuel cell can be manufactured according to a conventional method known in the art using the above-described membrane-electrode assembly (MEA). For example, the membrane electrode assembly (MEA) and the bipolar plate may be fabricated.

The fuel cell of the present invention comprises a stack, a fuel supply, and an oxidant supply.

3 schematically shows the structure of a fuel cell, which comprises a stack 60, an oxidant supply unit 70 and a fuel supply unit 80. [

The stack 60 includes one or more of the membrane electrode assemblies described above and includes a separator interposed therebetween when two or more membrane electrode assemblies are included. The separator serves to prevent the membrane electrode assemblies from being electrically connected and to transfer the fuel and oxidant supplied from the outside to the membrane electrode assembly.

The oxidant supply part 70 serves to supply the oxidant to the stack 60. As the oxidizing agent, oxygen is typically used, and oxygen or air can be injected into the pump 70 and used.

The fuel supply unit 80 serves to supply the fuel to the stack 60 and includes a fuel tank 81 for storing the fuel and a pump 82 for supplying the fuel stored in the fuel tank 81 to the stack 60 Lt; / RTI > As the fuel, gas or liquid hydrogen or hydrocarbon fuel may be used. Examples of hydrocarbon fuels include methanol, ethanol, propanol, butanol or natural gas.

The fuel cell may be a polymer electrolyte fuel cell, a direct liquid fuel cell, a direct methanol fuel cell, a direct formic acid fuel cell, a direct ethanol fuel cell, or a direct dimethyl ether fuel cell.

When the polymer electrolyte membrane according to one embodiment of the present invention is used as an ion exchange membrane of a fuel cell, the above-described effect can be obtained.

In addition, one embodiment of the present disclosure includes a positive electrode cell including a positive electrode and a positive electrode electrolyte; A negative electrode cell comprising a negative electrode and a negative electrode electrolyte; And a polymer electrolyte membrane according to an embodiment of the present invention provided between the anode cell and the cathode cell.

In another embodiment, there is provided a battery comprising: a positive electrode cell comprising a positive electrode and a positive electrode electrolyte; A negative electrode cell comprising a negative electrode and a negative electrode electrolyte; And a reinforcement film provided between the positive electrode cell and the negative electrode cell according to an embodiment of the present invention.

Redox Flow Battery (Redox Flow Battery) is a system in which an active substance contained in an electrolyte is oxidized and reduced to be charged and discharged. An electrochemical storage device that stores chemical energy of an active substance directly as electric energy to be. The redox flow battery utilizes the principle of charging and discharging electrons by receiving electrons when an electrolyte containing an active material having a different oxidation state meets the ion exchange membrane. Generally, a redox flow battery is composed of a tank containing an electrolyte solution, a battery cell in which charging and discharging occur, and a circulation pump circulating the electrolyte between the tank and the battery cell, and the unit cell of the battery cell includes an electrode, Exchange membrane.

When the electrolyte membrane according to one embodiment of the present invention is used as the ion exchange membrane of the redox flow cell, the above-described effect can be obtained.

The redox flow cell of the present specification can be produced according to a conventional method known in the art, except that it includes a polymer electrolyte membrane according to one embodiment of the present specification.

2, the redox flow battery is divided into a positive electrode cell 32 and a negative electrode cell 33 by an electrolyte film 31. As shown in FIG. The anode cell 32 and the cathode cell 33 each include an anode and a cathode. The anode cell (32) is connected to the anode tank (10) for supplying and discharging the anode electrolyte (41) through a pipe. The cathode cell 33 is also connected to a cathode tank 20 for supplying and discharging the cathode electrolyte 42 through a pipe. The electrolytic solution is circulated through the pumps 11 and 21, and an oxidation / reduction reaction (that is, a redox reaction) in which the oxidation number of ions is changed occurs, thereby charging and discharging occur in the anode and the cathode.

Hereinafter, the present invention will be described in more detail with reference to Production Examples and Experimental Examples. However, the following examples are intended to illustrate the invention and are not intended to limit the scope of the invention.

Synthetic example

≪ Preparation Example 1 &

The respective monomers and potassium carbonate (K ₂ CO ₃ : molar ratio 4) shown above were mixed at a ratio of 30 wt% of NMP and 20 wt% of benzene and polymerized at 140 ° C. for 4 hours and at 180 ° C. for 16 hours, .

≪ Example 1 >

The polymer obtained in Preparation Example 1 was dissolved in DMF at a concentration of 10 wt%, cooled to 0 ^° C, and excess SOCl ₂ was slowly added dropwise. The reaction was warmed to room temperature, stirred at room temperature for 24 hours, and distilled under reduced pressure to synthesize the polymer.

< Example  2>

The polymer obtained in Example 1 was cooled to 0 占 폚 and excess ammonia water was slowly added dropwise. The reaction was warmed to room temperature, stirred for 24 hours and then filtered. The polymer thus obtained was washed several times with water and then dried at room temperature to prepare the above polymer.

IR data of the polymer before crosslinking (Example 1) and after (Example 2) are shown in Fig.

<Experimental Example 1>

Molecular weight changes of the crosslinked polymer through the post-polymer reaction (before the crosslinking) and after the crosslinking (after crosslinking) were measured by GPC and the results are shown in Table 1 below. .

Mn Mw Mw / Mn Before post reaction 1.11E + 05 8.59E + 05 7.74 After post reaction 1.07E + 05 1.16E + 06 10.86

In order to test the chemical resistance of the crosslinked polymer, immersed it was observed a change in the solution color to a small amount of a film-forming polymer containing the V ^{5 +} ions aqueous solution of sulfuric acid (V ⁵⁺ ions electrolyte). V ⁵⁺ (VO ₂ ⁺ ) Ion is the most reactive among the VRB electrolytes. Transparent yellow V ⁵⁺ ion (VO ₂ ⁺ ) When the solution oxidizes the membrane, it is reduced to V ⁴⁺ (VO ²⁺ ) and turns opaque and dark green. If the V ^{5 +} ionic electrolyte is not discolored, it can be seen that the polymer is not oxidized by the V ^{5 +} ions. The above phenomenon was used to test the chemical resistance before and after crosslinking. The results of the acid resistance test conducted by immersing the polymer film formed for 15 days under the condition of 0.1 MV (V) -0.3 MH ₂ SO ₄ solution are shown in FIG.

After the chemical resistance test, the absorbance of each solution was measured by UV-VIS spectroscopy and the results are shown in Table 2 below.

Absorbance at 765 nm Before post reaction (before crosslinking) 0.10 After post reaction (after crosslinking) 0.05

As shown in Experimental Example 1, the electrolyte membrane prepared by using the polymer according to the present invention had an effect of increasing the durability of the electrolyte membrane by increasing the average molecular weight after the crosslinking reaction. Also, as a result of the acid resistance test in the aqueous solution of vanadium sulfate, It can be seen that the chemical resistance is greatly improved.

Therefore, when the fuel cell or the redox flow battery is manufactured using the electrolyte membrane according to the present application, the durability of the battery can be greatly improved.

100: electrolyte membrane
200a: anode
200b: cathode
10, 20: tank
11, 21: pump
31: electrolyte membrane
32: anode cell
33: cathode cell
41: anode electrolyte
42: cathode electrolyte
60: Stack
70: oxidant supplier
80: fuel supply unit
81: Fuel tank
82: Pump

Claims (16)

A polymer comprising two or more main chains connected by a crosslinking structure of the following formula (1): &lt; EMI ID =
[Chemical Formula 1]

In Formula 1,
R 1 to R 4 are the same or different and are each independently a halogen group,
D 1 and D 2 are the same or different and are each independently S, O, SO ₂ or NH,
a and b are each an integer of 2 to 20, the structures in parentheses are the same or different from each other,

Is a site connected to the main chain in the polymer. 3. The polymer of claim 1, wherein the polymer comprises units of the formula:
(2)

In Formula 2,
B 1 to B 4 are the same or different from each other, and are each independently S, O or SO ₂ ,
G1 and G2 are the same as or different from each other, and are each independently selected from O, S, SO _2, CO or CF _2,
c, d, p, q, r and s are each 0 or 1,
R1 to R4, D1 and D2 are as defined in formula (1). The polymer according to claim 2, wherein the formula (2) is represented by the following formula (3)
(3)

. 3. The polymer of claim 2, wherein the polymer further comprises a unit of the formula:
[Chemical Formula 4]

In Formula 4,
And B5 and B6 are the same as or different from each other and each independently represents S, O or SO _2,
G3 is O, S, SO _2, and CO ₂ or CF,
e, t and u are each 0 or 1,
D3 is S, O, SO ₂ or NH,
L is a divalent group containing at least one fluorine. 3. The polymer of claim 2, wherein the polymer further comprises a unit of formula (5): &lt; EMI ID =
[Chemical Formula 5]

In Formula 5,
A1 is a carbonyl group, a sulfonyl group or a sulfide group,
B7 is S, O or SO _2,
x is 0 or 1; The polymer according to claim 1, wherein the formula (1) is represented by the following formula (1-1):
[Formula 1-1]

The polymer according to claim 3, wherein the formula (3) is represented by one of the following formulas (3-1) to (3-4)
[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

[Chemical Formula 3-4]

The polymer according to claim 4, wherein the formula (4) is represented by one of the following formulas (4-1) to (4-3)
[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

The method of claim 1, wherein the polymer is a random copolymer comprising a hydrophilic unit and a hydrophobic unit; Or a block polymer comprising a hydrophilic block and a hydrophobic block. The polymer of claim 1, wherein the weight average molecular weight of the polymer is from 5,000 g / mol to 10,000,000 g / mol. A polymer electrolyte membrane comprising the polymer of any one of claims 1 to 10. materials; And a reinforcing film comprising the polymer of any one of claims 1 to 10. Anode; Cathode; And a polymer electrolyte membrane according to claim 11 provided between the anode and the cathode. Anode; Cathode; 12. The membrane-electrode assembly of claim 12, wherein the membrane is between the anode and the cathode. At least two membrane-electrode assemblies; A stack including a bipolar plate disposed between the membrane-electrode assemblies; A fuel supply unit for supplying fuel to the stack; And an oxidant supplier for supplying an oxidant to the stack, wherein the membrane-electrode assembly comprises an anode; Cathode; And a polymer electrolyte membrane or an enhancement membrane provided between the anode and the cathode, wherein the polymer electrolyte membrane or the enhancement membrane comprises the polymer according to any one of claims 1 to 10. The polymer electrolyte fuel cell according to claim 1, A positive electrode including a positive electrode and a positive electrode electrolyte; A negative electrode cell comprising a negative electrode and a negative electrode electrolyte; And a polymer electrolyte membrane or a reinforcement membrane provided between the positive electrode cell and the negative electrode cell, wherein the polymer electrolyte membrane or the reinforcement membrane comprises a polymer according to any one of claims 1 to 10, .

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