CN110129818A - Proton exchange membrane water electrolyzer - Google Patents

Abstract

The invention relates to a proton exchange membrane water electrolyzer, comprising a proton exchange membrane, a cathode catalyst layer, an anode catalyst layer, a cathode diffusion layer and an anode diffusion layer, and the cathode catalyst layer and the anode catalyst layer are respectively sprayed on both sides of the proton exchange membrane to form Three-in-one membrane electrode, the membrane electrode is installed in the middle of the middle substrate, the two sides of the middle substrate are respectively provided with a cathode flow field plate and an anode flow field plate, the left end of the cathode flow field plate is provided with a left epoxy resin plate, and the anode flow field plate is provided with a left epoxy resin plate. The right end of the field plate is provided with a right epoxy resin plate, the middle of the left epoxy resin plate and the right epoxy resin plate are embedded with a collector plate, the left end plate, the left epoxy resin plate, the cathode flow field plate, the middle substrate, The anode field flow plate, the right epoxy resin plate and the right end plate are provided with communicating gas-liquid channels. The invention can improve the electrolysis efficiency, reduce the current loss, reduce the quality and volume of the water electrolyzer, reduce the difficulty of assembly and prolong the service life of the water electrolyzer.

Description

Proton exchange membrane water electrolyzer

technical field

The invention relates to the field of proton exchange membrane electrolyzed water, in particular to a proton exchange membrane water electrolyzer.

Background technique

Hydrogen energy is regarded as the most ideal energy carrier due to its clean, pollution-free, efficient, storable and transportable advantages. Hydrogen production by electrolysis of water is currently the easiest way to obtain pure hydrogen. If it is combined with renewable resource power generation technology, electrolysis of water can be used as a large-scale hydrogen production technology, which has less environmental pollution, less greenhouse gas emissions, and is more economical. Well, it has a good application prospect.

Proton exchange membrane electrolysis water technology is to generate oxygen and hydrogen through electrolysis of water. Deionized water flows into the channel through the deionized water, diffuses to the anode side of the proton exchange membrane through the diffusion layer, and electrolyzes oxygen and hydrogen ions under the action of the catalyst. The deionized water that did not participate in the electrolysis flows out of the electrolytic cell through the oxygen-containing deionized water channel, while the hydrogen ions pass through the proton exchange membrane to the cathode side, then generate hydrogen gas, and flow into the hydrogen discharge channel through the cathode diffusion layer, and then flow out of the electrolytic cell.

Proton exchange membrane electrolysis water technology is currently the most effective among several electrolysis water technologies. The technology based on pure water electrolysis developed by the American General Company in the 1970s is still in the research and development stage. As an electrolyte, the proton exchange membrane has the advantages of good mechanical strength and chemical stability, high proton conductivity and good gas separation, which can make the PEM electrolyzer work at a higher current without reducing the electrolysis efficiency. The use of pure water electrolysis avoids the corrosion of the electrolyte on the tank body, and is a highly safe water electrolysis technology. However, in the proton exchange membrane water electrolyzer in the prior art, flow field plates with various flow channels need to be designed, and the structure is complex and bulky, resulting in difficult processing and high manufacturing cost.

Contents of the invention

The technical problem to be solved by the present invention is to provide a proton exchange membrane water electrolyzer with a compact structure, which can improve the electrolysis efficiency, reduce the current loss, reduce the quality and volume of the water electrolyzer, reduce the difficulty of assembly, and prolong the service life of the water electrolyzer .

The technical solution adopted by the present invention to solve its technical problems is: construct a kind of proton exchange membrane water electrolyzer, comprise proton exchange membrane, cathode catalyst layer, anode catalyst layer, cathode diffusion layer and anode diffusion layer, described cathode catalyst layer and The anode catalytic layer is sprayed on both sides of the proton exchange membrane to form a membrane electrode with a three-in-one structure. The membrane electrode is installed in the middle of the intermediate substrate, and the two sides of the intermediate substrate are respectively equipped with a cathode flow field plate and an anode flow field plate. , the cathode diffusion layer is inlaid in the middle of the cathode flow field plate, the anode diffusion layer is inlaid in the middle of the anode flow field plate, the left end of the cathode flow field plate is provided with a left epoxy resin plate, and the anode flow field The right end of the plate is provided with a right epoxy resin plate, the middle of the left epoxy resin plate and the right epoxy resin plate are both embedded with a current collecting plate, and the left side of the left epoxy resin plate is provided with a left end plate, so The right side of the right epoxy resin plate is provided with a right end plate; the left end plate, the left epoxy resin plate, the cathode flow field plate, the middle substrate, the anode flow field plate, the right epoxy resin plate and the right end plate are fixedly connected, and All are provided with interlinked gas-liquid channels.

In the above scheme, the anode diffusion layer adopts a multi-layer titanium mesh plus titanium felt structure, the titanium mesh aperture gradually becomes smaller from the cathode flow field plate side to the membrane electrode side, and the titanium mesh aperture is from the anode flow field plate side to the membrane electrode side is gradually getting smaller.

In the above solution, the cathode diffusion layer adopts a multi-layer carbon paper structure.

In the above solution, the cathode diffusion layer is interference-fitted with the flow field plate.

In the above solution, the surfaces of the cathode flow field plate and the anode flow field plate are slightly convex.

In the above solution, the edge of the collector plate is provided with a connecting ear plate for connecting the power supply.

In the above scheme, the contact surfaces of the left end plate, the left epoxy resin plate, the cathode flow field plate, the middle substrate, the anode flow field plate, the right epoxy resin plate and the right end plate are all provided with sealing grooves, and inside the sealing grooves Install the seal.

In the above solution, the gas-liquid channels include a channel for deionized water entering the electrolyzer at the bottom, a channel for oxygen-containing deionized water flowing out of the electrolyzer at the top, and channels for hydrogen to exit the electrolyzer at the left and right sides.

In the above solution, the edges of the cathode flow field plate, the anode flow field plate, the left epoxy resin plate, the right epoxy resin plate, the left end plate, and the right end plate are all provided with bolt holes.

In the above solution, the edges of the cathode flow field plate, the anode flow field plate, the left epoxy resin plate, the right epoxy resin plate, the left end plate, and the right end plate are provided with positioning holes.

Implementing the proton exchange membrane water electrolyzer of the present invention has the following beneficial effects:

1. The present invention realizes the circulation of gas and liquid through the corresponding gas-liquid channels between the plates, without setting complicated flow channels, and the use of flow field plates without flow channels can reduce processing difficulty and cost.

2. No flow channel design is adopted, the cathode and anode gas diffusion layers are embedded in the flow field plate, and the cathode diffusion layer and the flow field plate have an interference fit to ensure that the carbon paper has a certain compression rate, which is beneficial to the contact between the diffusion layer and the membrane electrode. Gas out.

3. The flow field plate of the present invention adopts slightly convex design, which can improve the contact effect between the proton exchange membrane and the diffusion layer when the electrolytic cell is assembled, prevent the swelling and deformation of the proton exchange membrane, and thus improve the electrolysis efficiency.

4. The anode diffusion layer of the present invention adopts a multi-layer titanium mesh plus titanium felt structure, and the titanium mesh aperture gradually becomes smaller from the flow field plate side to the membrane electrode side, and titanium felt is placed between the titanium mesh and the membrane electrode. The cathode diffusion layer adopts a multi-layer carbon paper structure, which is beneficial to the water vapor transmission and the contact between the diffusion layer and the membrane electrode, reduces the contact resistance, improves the water electrolysis performance, and can also prevent the corrosion of the diffusion layer.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the structural representation of proton exchange membrane water electrolyzer of the present invention;

Fig. 2 is a schematic diagram of the exploded parts of Fig. 1;

Fig. 3 is the structural representation of proton exchange membrane;

Fig. 4 is the structural representation of cathode flow field plate;

Fig. 5 is the structural representation of anode flow field plate;

Fig. 6 is a schematic structural view of a collector plate;

Fig. 7 is a schematic structural view of the left end plate or the right end plate;

Fig. 8 is a schematic structural view of another embodiment of the flow field plate. .

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in Figure 1-7, proton exchange membrane 1 water electrolyzer of the present invention comprises proton exchange membrane 1, cathode catalyst layer, anode catalyst layer, cathode diffusion layer 2, anode diffusion layer 3, cathode flow field plate 4, anode flow field Field plate 5 , left epoxy resin plate 6 , right epoxy resin plate 7 , left end plate 8 and right end plate 9 . The left end plate 8, the left epoxy resin plate 6, the cathode flow field plate 4, the middle substrate 10, the anode field flow plate, the right epoxy resin plate 7 and the right end plate 9 are fixedly connected, and are provided with communicating gas-liquid channels.

The cathode catalytic layer and the anode catalytic layer are respectively sprayed on both sides of the proton exchange membrane 1 to form a three-in-one membrane electrode, which is convenient for assembly. The membrane electrode is installed in the middle of the intermediate substrate 10 . The electrolyte is a proton exchange membrane 1, which is a relatively mature proton exchange membrane 1 at present. It has the advantages of high proton conductivity, good electrochemical stability, certain mechanical strength, and high gas barrier performance. The cathode catalytic layer and the anode catalytic layer are respectively sprayed on both sides of the proton exchange membrane 1 to form a three-in-one structure. This structure can reduce the catalyst loading, and can also significantly increase the active surface area and chemical stability of the catalyst, and reduce the proton conduction resistance.

Both sides of the intermediate substrate 10 are respectively provided with a cathode flow field plate 4 and an anode flow field plate 5 , the cathode diffusion layer 2 is embedded in the middle of the cathode flow field plate 4 , and the anode diffusion layer 3 is embedded in the middle of the anode flow field plate 5 . The anode diffusion layer 3 adopts a multi-layer titanium mesh and titanium felt structure, and the diameter of the titanium mesh gradually decreases from the flow field plate side to the membrane electrode side. In addition, titanium felt is placed between the titanium mesh and the membrane electrode, which is beneficial to the water vapor The contact between the transmission and diffusion layer and the membrane electrode reduces the contact resistance and improves the performance of water electrolysis. The cathode diffusion layer 2 adopts a multi-layer carbon paper structure, which is beneficial to the water vapor transmission and the contact between the diffusion layer and the membrane electrode, reduces the contact resistance, and improves the water electrolysis performance. Determine the number of carbon paper layers according to their cooperation with the flow field plate, and stick together, without affecting the diffusion performance and reducing the difficulty of assembly.

The cathode flow field plate 4 and the anode flow field plate 5 are made of pure titanium with surface coating, which has the advantages of reducing DC current loss, corrosion resistance and long service life. The cathode flow field plate 4 and the anode flow field plate 5 adopt a slightly convex design to ensure overall force balance, prevent irregular deformation of the proton exchange membrane 1, and improve water electrolysis performance. The cathode flow field plate 4 and the anode flow field plate 5 are designed without flow channels, the cathode gas diffusion layer and the anode gas diffusion layer are embedded in the flow field plate, and the cathode diffusion layer 2 and the cathode flow field plate 4 are interference fit to ensure the carbon The paper has a certain compressibility, which is beneficial to the contact between the cathode diffusion layer 2 and the membrane electrode and the discharge of gas.

The structure of the proton exchange membrane 1 water electrolyzer in this embodiment is a single proton exchange membrane 1 electrolyzer structure, but it is also applicable to the electrolyzer with multiple proton exchange membrane 1 connected in series. The side is the cathode and anode flow field plates 5 as two adjacent single electrolytic cell structures, that is, the cathode side flow field and the anode side flow field are integrated into one flow field plate, as shown in FIG. 8 .

The left end of the cathode flow field plate 4 is provided with a left epoxy resin plate 6, the right end of the anode flow field plate 5 is provided with a right epoxy resin plate 7, and the middle parts of the left epoxy resin plate 6 and the right epoxy resin plate 7 are all embedded Collector plate 11 is arranged. The current collecting plate 11 is a copper plate with a gold-plated surface, which can reduce resistance, reduce energy consumption, and prevent corrosion. The current collecting plate 11 is embedded in the epoxy resin plate, which can enhance the insulation performance, and is also beneficial to reduce the overall volume of the electrolytic cell. In addition, the collector plate 11 is designed with an extension connecting lug plate 12 for connecting to a DC power supply.

A left end plate 8 is provided on the left side of the left epoxy resin plate 6 , and a right end plate 9 is provided on the right side of the right epoxy resin plate 7 . The left end plate 8 and the right end plate 9 are made of aluminum alloy, and pipe joints are installed outside the end plates for the transmission of gas and liquid. The advantage is that the rigidity and strength of the end plates can be guaranteed, and the weight of the entire water electrolyzer can be reduced.

The contact surfaces of left end plate 8, left epoxy resin plate 6, cathode flow field plate 4, middle substrate 10, anode field flow plate, right epoxy resin plate 7 and right end plate 9 are all provided with sealing grooves, and sealing grooves are installed in the sealing grooves. lock up.

The gas-liquid channels include a channel 15 for deionized water entering the electrolyzer at the bottom, a channel 14 for oxygen-containing deionized water flowing out of the electrolyzer at the top, and channels 13 for hydrogen to exit the electrolyzer at the left and right sides. The edges of the cathode flow field plate 4, the anode flow field plate 5, the left epoxy resin plate 6, the right epoxy resin plate 7, the left end plate 8 and the right end plate 9 are all provided with bolt holes 16 for installing fastening bolts. The cathode flow field plate 4, the anode flow field plate 5, the left epoxy resin plate 6, the right epoxy resin plate 7, the left end plate 8, and the right end plate 9 are provided with positioning holes 17, which can provide precise positioning when the electrolytic cell is assembled .

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection of the present invention.

Claims (10)

1. A proton exchange membrane water electrolyzer, comprising proton exchange membrane, cathode catalyst layer, anode catalyst layer, cathode diffusion layer and anode diffusion layer, is characterized in that, described cathode catalyst layer and anode catalyst layer are sprayed on proton exchange layer respectively On both sides of the membrane, a membrane electrode with a three-in-one structure is formed. The membrane electrode is installed in the middle of the intermediate substrate. The two sides of the intermediate substrate are respectively provided with a cathode flow field plate and an anode flow field plate. The cathode diffusion layer is embedded in the The middle part of the cathode flow field plate, the anode diffusion layer is embedded in the middle part of the anode flow field plate, the left end of the cathode flow field plate is provided with a left epoxy resin plate, and the right end of the anode flow field plate is provided with a right epoxy resin plate. Resin plate, the middle of the left epoxy resin plate and the right epoxy resin plate are all embedded with a collector plate, the left side of the left epoxy resin plate is provided with a left end plate, the right epoxy resin plate of the right There is a right end plate on the side; the left end plate, the left epoxy resin plate, the cathode flow field plate, the middle base plate, the anode flow field plate, the right epoxy resin plate and the right end plate are fixedly connected, and all have connected gas-liquid channels . 2. proton exchange membrane water electrolyzer according to claim 1, is characterized in that, described anode diffusion layer adopts multi-layer titanium mesh to add titanium felt structure, and titanium mesh aperture is gradually from cathode flow field plate side to membrane electrode side. becomes smaller, the pore size of the titanium mesh gradually decreases from the anode flow field plate side to the membrane electrode side. 3. The proton exchange membrane water electrolyzer according to claim 1, wherein the cathode diffusion layer adopts a multilayer carbon paper structure. 4. The proton exchange membrane water electrolyzer according to claim 1, characterized in that, the cathode diffusion layer is in interference fit with the flow field plate. 5. The proton exchange membrane water electrolyzer according to claim 1, characterized in that the surfaces of the cathode flow field plate and the anode flow field plate are slightly convex. 6. The proton exchange membrane water electrolyzer according to claim 1, characterized in that, the edge of the collector plate is provided with a connecting ear plate for connecting to a power supply. 7. proton exchange membrane water electrolyzer according to claim 1, is characterized in that, described left end plate, left epoxy resin plate, cathode flow field plate, intermediate substrate, anode field flow plate, right epoxy resin plate and The contact surfaces of the right end plates are all provided with sealing grooves, and sealing rings are installed in the sealing grooves. 8. The proton exchange membrane water electrolyzer according to claim 1, characterized in that, the gas-liquid channels include deionized water below and enter the electrolyzer passage, the oxygen-containing deionized water above flow out of the electrolyzer passage and the The left and right sides are the channels for hydrogen to discharge from the electrolyzer. 9. proton exchange membrane water electrolyzer according to claim 1, is characterized in that, described cathode flow field plate, anode flow field plate, left epoxy resin plate, right epoxy resin plate, left end plate, right end plate Bolt holes are provided on the edges. 10. proton exchange membrane water electrolyzer according to claim 9, is characterized in that, described cathode flow field plate, anode flow field plate, left epoxy resin plate, right epoxy resin plate, left end plate, right end plate Positioning holes are arranged on the edge.