An industrial aem hydrogen production electrolyzer

Abstract

This invention discloses an industrial AEM hydrogen production electrolyzer, comprising, from left to right, a left end pressure plate, a left electrode plate, a first membrane electrode, a bipolar plate, a second membrane electrode, a right electrode plate, and a right end pressure plate; the right side of the left electrode plate and the right side of the bipolar plate are the cathode sides, forming a cathode reaction chamber between the cathode side and the first membrane electrode, and a cathode diffusion layer is disposed inside the cathode reaction chamber; the left side of the bipolar plate and the left side of the right electrode plate are the anode sides, forming an anode reaction chamber between the anode side and the second membrane electrode, and an anode diffusion layer is disposed inside the anode reaction chamber; cathode flow equalization components are respectively disposed on the cathode sides of the bipolar plate and the left electrode plate; anode flow equalization components are respectively disposed on the anode sides of the bipolar plate and the right electrode plate; this invention provides flow equalization components at the electrolyte inlet, effectively avoiding local gas blockage and flow dead zones, and overcoming the defects of uneven gas-liquid distribution and pressure imbalance in the process of large-scale single-cell electrolyzer production.

Description

Technical Field

[0001] This invention relates to the field of hydrogen electrolyzer technology, specifically to an industrial AEM hydrogen electrolyzer. Background Technology

[0002] Anion exchange membrane (AEM) water electrolysis for hydrogen production combines the low-cost advantages of alkaline electrolyzers with the high efficiency and flexibility of proton exchange membrane (PEM) electrolyzers, representing a significant development direction in the field of electrolytic hydrogen production in recent years. During operation, the electrolyte enters the reaction chamber through fluid inlets on both the anode and cathode sides of the AEM electrolyzer, where electrochemical reactions occur on both sides of the membrane electrodes. The feed water gains electrons at the cathode, undergoing a reduction reaction to produce hydrogen and hydroxide ions. The hydroxide ions then pass through the anion exchange membrane to the anode, where they lose electrons and undergo an oxidation reaction to produce oxygen and water.

[0003] Existing AEM electrolyzers have the following problems in practical applications: 1) Poor uniformity of fluid distribution in the reaction chamber: After the electrolyte enters the reaction flow field from the inlet, it is prone to "finding effect" and flow dead zone, resulting in uneven local reaction of the membrane electrode, excessively high or low current density in some areas, large contact resistance and concentrated current distribution, which affects electrolysis efficiency and membrane electrode life; 2) Poor gas-liquid two-phase flow transmission: As the electrochemical reaction proceeds, hydrogen is generated on the cathode side and oxygen is generated on the anode side. The generation and growth of bubbles will change the flow resistance distribution in the flow channel, resulting in uneven distribution of gas and liquid phases in the flow channel, severe local gas blockage, and increased concentration polarization overpotential; 3) Imbalance in pressure and stress distribution inside traditional electrolyzers, which can easily cause mechanical damage to components or even membrane rupture.

[0004] Furthermore, existing AEM electrolyzer patents mainly target small-scale electrolyzers for laboratory research. Existing AEM hydrogen production electrolyzers all employ a single electrolyte inlet and outlet, use parallel or multi-serpentine flow fields, and have an effective electrode area ≤300 cm². 2 This type of electrolytic cell is mostly used in 2Nm 3 Small-scale hydrogen production scenarios or laboratory research with a capacity of less than [amount] / h are difficult to apply to large-scale electrolyzers. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an industrial AEM hydrogen production electrolyzer to solve the problems of uneven gas-liquid distribution and unbalanced pressure distribution during the process of scaling up single electrolyzers.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows.

[0007] An industrial AEM hydrogen production electrolyzer includes, from left to right, a left end plate, a left electrode plate, a first membrane electrode, a bipolar plate, a second membrane electrode, a right electrode plate, and a right end plate. The right sides of the left electrode plate and the bipolar plate are cathode sides, forming a cathode reaction chamber between the cathode side and the first membrane electrode, with a cathode diffusion layer disposed inside the cathode reaction chamber. The left sides of the bipolar plate and the left sides of the right electrode plate are anode sides, forming an anode reaction chamber between the anode side and the second membrane electrode, with an anode diffusion layer disposed inside the anode reaction chamber. Cathode flow equalization components are respectively disposed on the cathode sides of the bipolar plate and the left electrode plate, each including a cathode fluid inlet, a cathode inlet flow equalization transition zone, a cathode reaction flow field, a cathode outlet flow equalization transition zone, and a cathode fluid outlet. Anode flow equalization components are respectively disposed on the anode sides of the bipolar plate and the right electrode plate, each including an anode fluid inlet, an anode inlet flow equalization transition zone, an anode reaction flow field, an anode outlet flow equalization transition zone, and an anode fluid outlet.

[0008] In the aforementioned industrial AEM hydrogen electrolyzer, a first insulating gasket is provided between the left end pressure plate and the left electrode plate, and a second insulating gasket is provided between the right end pressure plate and the right electrode plate.

[0009] In the aforementioned industrial AEM hydrogen electrolyzer, a first sealing gasket and a second sealing gasket are respectively provided on both sides of the first membrane electrode and the second membrane electrode. The first sealing gasket is located on the cathode side of the first membrane electrode and the second membrane electrode, and the second sealing gasket is located on the anode side of the first membrane electrode and the second membrane electrode.

[0010] In the aforementioned industrial AEM hydrogen electrolyzer, the left end pressure plate, left electrode plate, first membrane electrode, bipolar plate, second membrane electrode, first insulating gasket, first sealing gasket, and second sealing gasket are respectively provided with a first liquid channel inlet, a first gas-liquid channel outlet, a second liquid channel inlet, and a second gas-liquid channel outlet. The first liquid channel inlet and the first gas-liquid channel outlet are respectively connected to the anode reaction chamber, and the second liquid channel inlet and the second gas-liquid channel outlet are respectively connected to the cathode reaction chamber.

[0011] In the aforementioned industrial AEM hydrogen production electrolyzer, L-shaped flow guide columns are respectively installed inside the cathode inlet flow equalization transition zone, cathode outlet flow equalization transition zone, anode inlet flow equalization transition zone, and anode outlet flow equalization transition zone. The L-shaped flow guide columns are located in the direction of the inlet or outlet of the reaction chamber, and the bent part of the L-shaped flow guide column is oriented towards the fluid flow direction. The cathode inlet flow equalization transition zone and the cathode outlet flow equalization transition zone are also provided with a group of transition flow equalization cylinders located inside the L-shaped flow guide columns.

[0012] The aforementioned industrial AEM hydrogen electrolyzer has a cathode reaction flow field consisting of two vertical parallel channels, with a group of cathode flow field equalizing cylinders arranged between the vertical parallel channels for gas-liquid redistribution.

[0013] The aforementioned industrial AEM hydrogen electrolyzer has an anode reaction flow field consisting of three horizontal parallel channels, with a group of anode flow field equalizing cylinders arranged between the horizontal parallel channels for gas-liquid redistribution.

[0014] The above-mentioned industrial AEM hydrogen production electrolyzer has a first membrane electrode and a second membrane electrode composed of an anode electrode, an anion exchange membrane, and a cathode electrode, respectively.

[0015] The aforementioned industrial AEM hydrogen electrolyzer, wherein the left electrode plate, bipolar plate, and right electrode plate are made of either nickel-plated stainless steel or pure nickel.

[0016] The technological advancements achieved by this invention are as follows, thanks to the adoption of the above technical solutions.

[0017] This invention provides an industrial AEM hydrogen production electrolyzer. A flow equalization component is installed at the electrolyte inlet. L-shaped guide columns and a group of transitional flow equalization cylinders disperse and evenly distribute the fluid before it enters the reaction chamber, avoiding localized flow concentration caused by the inlet jet and resulting in a more uniform current density distribution on the membrane electrode surface. By setting up the flow equalization cylinder group in the reaction flow field, gas-liquid redistribution between adjacent flow channels is achieved, effectively avoiding localized gas blockage and flow dead zones, improving the flow uniformity of the gas-liquid mixture, and overcoming the defects of uneven gas-liquid distribution and pressure imbalance during the scaling up of single-cell electrolyzers. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the specific structure of the present invention; Figure 2 This is an exploded structural diagram of the present invention; Figure 3 This is a schematic diagram of the specific structure of the cathode current equalization assembly; Figure 4 This is a schematic diagram of the specific structure of the anode current equalization component.

[0019] Wherein: 101. Left end pressure plate, 102. Left electrode plate, 103. First membrane electrode, 104. Bipolar plate, 105. Second membrane electrode, 106. Right electrode plate, 107. Right end pressure plate, 108. Cathode diffusion layer, 109. Anode diffusion layer, 110. Cathode fluid inlet, 111. Cathode inlet flow equalization transition zone, 112. Cathode reaction flow field, 113. Cathode outlet flow equalization transition zone, 114. Cathode fluid outlet, 115. Anode fluid inlet, 116. Anode inlet flow equalization transition zone, 117. Anode reaction flow field, 118. Anode outlet... 119. Anode fluid outlet; 120. L-shaped guide column; 121. Transition flow equalization cylinder group; 122. Vertical parallel flow channel; 123. Cathode flow field equalization cylinder group; 124. Horizontal parallel flow channel; 125. Anode flow field equalization cylinder group; 126. First insulating gasket; 127. Second insulating gasket; 128. First sealing gasket; 129. Second sealing gasket; 130. First liquid channel inlet; 131. First gas-liquid channel outlet; 132. Second liquid channel inlet; 133. Second gas-liquid channel outlet. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] An industrial AEM hydrogen production electrolyzer, such as Figures 1 to 4 As shown, the device includes a left end pressure plate 101, a left electrode plate 102, a first membrane electrode 103, a bipolar plate 104, a second membrane electrode 105, a right electrode plate 106, and a right end pressure plate 107 arranged sequentially from left to right. The left end pressure plate 101 and the right end pressure plate 107 are connected by fastening bolts.

[0022] The right side of the left electrode plate 102 and the right side of the bipolar plate 104 are the cathode sides, respectively. A cathode reaction cavity is formed between the cathode side and the first membrane electrode 103, and a cathode diffusion layer 108 is disposed inside the cathode reaction cavity.

[0023] The cathode diffusion layer 108 is usually made of porous metal materials such as nickel foam or nickel mesh, which serves to support the membrane electrode, conduct electrons, distribute fluid, and expel hydrogen bubbles.

[0024] The left side of the bipolar plate 104 and the left side of the right electrode 106 are the anode side. An anode reaction chamber is formed between the anode side and the second membrane electrode 105. An anode diffusion layer 109 is provided inside the anode reaction chamber.

[0025] The anode diffusion layer 109 is typically made of porous nickel-based material and serves to support the membrane electrode, conduct electrons, distribute fluid, and expel oxygen bubbles.

[0026] The thickness of the cathode diffusion layer 108 and the anode diffusion layer 109 is 0.5-2.0 mm, and the porosity is 60-95%.

[0027] A first insulating gasket 126 is provided between the left end pressure plate 101 and the left electrode plate 102, and a second insulating gasket 127 is provided between the right end pressure plate 107 and the right electrode plate 106. The insulating gaskets can prevent electrical conduction between the end pressure plates and the electrode plates, thus avoiding external short circuits after the electrolytic cell is assembled.

[0028] In this embodiment, the insulating gasket is made of modified polytetrafluoroethylene, and the thickness of the insulating gasket is 3-8 mm.

[0029] A first sealing gasket 128 and a second sealing gasket 129 are respectively provided on both sides of the first membrane electrode 103 and the second membrane electrode 105. The first sealing gasket 128 is located on the cathode side of the first membrane electrode 103 and the second membrane electrode 105, and the second sealing gasket 129 is located on the anode side of the first membrane electrode 103 and the second membrane electrode 105. This can prevent the electrolyte from leaking from the reaction chamber to the outside, and at the same time prevent the fluids on the cathode side and the anode side from flowing through the edge of the membrane electrode.

[0030] In this embodiment, the first sealing gasket 128 and the second sealing gasket 129 are made of modified polytetrafluoroethylene with a thickness of 0.5-2.5 mm.

[0031] The left end pressure plate 101, the first insulating gasket 126, the left electrode plate 102, the first sealing gasket 128, the first membrane electrode 103, the second sealing gasket 129, and the bipolar plate 104 are respectively provided with a first liquid channel inlet 130, a first gas-liquid channel outlet 131, a second liquid channel inlet 132, and a second gas-liquid channel outlet 133. The first liquid channel inlet and the first gas-liquid channel outlet are respectively connected to the anode reaction chamber, and the second liquid channel inlet and the second gas-liquid channel outlet are respectively connected to the cathode reaction chamber.

[0032] The cathode side of the bipolar plate 104 and the left electrode plate 102 are respectively provided with cathode flow equalization components. The cathode flow equalization components include cathode fluid inlet 110, cathode inlet flow equalization transition zone 111, cathode reaction flow field 112, cathode outlet flow equalization transition zone 113, and cathode fluid outlet 114.

[0033] In this embodiment, the cathode fluid inlet 110 and the cathode fluid outlet 114 are elliptical through holes, and two cathode fluid inlets 110 and two cathode fluid outlets 114 are respectively provided.

[0034] The cathode fluid inlet 110 is connected to the external electrolyte supply pipeline, and L-shaped flow guide columns 120 are respectively installed inside the cathode inlet flow equalization transition zone 111 and the cathode outlet flow equalization transition zone 113.

[0035] The L-shaped guide column 120 is located in the direction of the inlet or outlet of the reaction chamber, and the bent part of the L-shaped guide column 120 is set towards the direction of fluid flow.

[0036] The L-shaped guide columns 120 are arranged in a pyramid-shaped array, and the density of the L-shaped guide columns increases sequentially from the inlet to the outlet.

[0037] In the inlet transition zone, the L-shaped guide column can reduce the direct impact of the fluid on the area directly opposite the inlet and divert the fluid; in the outlet transition zone, the L-shaped guide column can guide the gas-liquid mixture to flow smoothly to the outlet and complete the convergence.

[0038] The cathode inlet flow equalization transition zone 111 and the cathode outlet flow equalization transition zone 113 are also provided with a group of transition flow equalization cylinders 121 located inside the L-shaped guide column 120. Through the flow around effect of the cylinder group, the flow dead zone is further eliminated and the uniformity of gas-liquid mixing is improved.

[0039] The cathode reaction flow field 112 consists of two vertical parallel flow channels 122. Between the two vertical parallel flow channels 122, there is a group of cathode flow field equalizing cylinders 123 for gas-liquid redistribution to avoid local gas blockage.

[0040] In the cathode reaction flow field region, the electrolyte undergoes a hydrogen evolution reaction on the cathode side of the membrane electrode under the action of an electric field. The generated hydrogen gas and unreacted electrolyte form a gas-liquid two-phase mixture, which is then redistributed through the cathode outlet flow equalization transition zone before being discharged through the cathode fluid outlet.

[0041] Anode flow equalization components are respectively provided on the anode side of bipolar plate 104 and right electrode plate 106. The anode flow equalization components include anode fluid inlet 115, anode inlet flow equalization transition zone 116, anode reaction flow field 117, anode outlet flow equalization transition zone 118, and anode fluid outlet 119.

[0042] In this embodiment, the anode fluid inlet 115 and the anode fluid outlet 119 are circular through holes, and there are three anode fluid inlets 115 and three anode fluid outlets 119.

[0043] The anode fluid inlet 115 is connected to the external electrolyte supply pipeline, and L-shaped guide columns 120 are respectively installed inside the anode inlet flow equalization transition zone 116 and the anode outlet flow equalization transition zone 118.

[0044] The anodic reaction flow field 117 consists of three horizontal parallel flow channels 124, and a group of anodic flow field equalizing cylinders 125 for gas-liquid redistribution is arranged between the three horizontal parallel flow channels 124.

[0045] The first membrane electrode 103 and the second membrane electrode 105 are respectively composed of an anode electrode, an anion exchange membrane and a cathode electrode.

[0046] The anion exchange membrane is located in the middle layer and plays a role in conducting hydroxide ions (OH-). - To isolate hydrogen and oxygen, the anode and cathode electrodes are bonded to the anion exchange membrane by hot-pressing.

[0047] The main chain material of the anion exchange membrane includes one of polyarylpiperidine, polyphenylene, polyethylene, polystyrene, and polyetheretherketone. The anode electrode is prepared by CCS process using an anode catalyst and nickel felt. The cathode electrode is prepared by CCS process using a cathode catalyst and carbon. The anode catalyst material includes nickel-iron catalyst, and the cathode catalyst includes platinum-carbon catalyst.

[0048] The cathode inlet flow equalization transition zone 111 and the anode inlet flow equalization transition zone 116 are tapered structures that gradually expand along the fluid flow direction, while the cathode outlet flow equalization transition zone 113 and the anode outlet flow equalization transition zone 118 are tapered structures that gradually contract along the fluid flow direction.

[0049] The left end pressure plate 101 and the right end pressure plate 107 are made of nickel-plated carbon steel, and the thickness of the left end pressure plate and the right end pressure plate is 20-50mm.

[0050] The materials of the left electrode plate 102, bipolar plate 104, and right electrode plate 106 are either stainless steel plated with nickel or pure nickel, and the thickness of the left electrode plate, right electrode plate, and bipolar plate is 2-5mm.

[0051] The left and right pressure plates have the same length and width. The left electrode plate, the first membrane electrode, the bipolar plate, the second membrane electrode, the right electrode plate, the first sealing gasket, and the second sealing gasket have the same length and width, and their areas are smaller than those of the left and right pressure plates.

[0052] During assembly, the left end pressure plate 101, the first insulating gasket 126, the left electrode plate 102, the first sealing gasket 128, the cathode diffusion layer 108, the first membrane electrode 103, the anode diffusion layer 109, the second sealing gasket 129, the bipolar plate 104, the first sealing gasket 128, the cathode diffusion layer 108, the second membrane electrode 105, the anode diffusion layer 109, the second sealing gasket 129, the right electrode plate 106, the second insulating gasket 127, and the right end pressure plate 107 are stacked sequentially from left to right. The parts are then locked and connected sequentially by fastening bolts. At the same time, the first liquid channel inlet, the first gas-liquid channel outlet, the second liquid channel inlet, and the second gas-liquid channel outlet on each component are naturally aligned after stacking, forming four longitudinal channels that run through the electrolytic cell.

[0053] During operation, the electrolyte enters the electrolytic cell from the cathode side of the second liquid channel inlet and the anode side of the first liquid channel inlet, respectively. It is then distributed to the cathode and anode reaction chambers of each individual cell via the cathode and anode fluid inlets of each electrode. At the cathode side, water is reduced to hydrogen gas and hydroxide ions (OH-). - Hydroxide ions migrate through the anion exchange membrane to the anode side, where they are oxidized into oxygen and water. The generated hydrogen and oxygen are discharged from the cathode fluid outlet and anode fluid outlet, respectively, along with the unreacted electrolyte. They are then collected at the outlets of the first and second gas-liquid channels and exited from the electrolytic cell.

Claims

1. An industrial AEM hydrogen production electrolyzer, characterized in that: The device includes, from left to right, a left end pressure plate (101), a left electrode plate (102), a first membrane electrode (103), a bipolar plate (104), a second membrane electrode (105), a right electrode plate (106), and a right end pressure plate (107). The right side of the left electrode plate (102) and the right side of the bipolar plate (104) are the cathode sides, and a cathode reaction cavity is formed between the cathode side and the first membrane electrode (103). A cathode diffusion layer (108) is disposed inside the cathode reaction cavity. The left side of the bipolar plate (104) and the left side of the right electrode plate (106) are the anode sides, and an anode reaction cavity is formed between the anode side and the second membrane electrode (105). An anode diffusion layer is disposed inside the anode reaction cavity. Layer (109); The cathode side of the bipolar plate (104) and the left electrode plate (102) are respectively provided with cathode flow equalization components, the cathode flow equalization components include cathode fluid inlet (110), cathode inlet flow equalization transition zone (111), cathode reaction flow field (112), cathode outlet flow equalization transition zone (113), and cathode fluid outlet (114); The anode side of the bipolar plate (104) and the right electrode plate (106) are respectively provided with anode flow equalization components, the anode flow equalization components include anode fluid inlet (115), anode inlet flow equalization transition zone (116), anode reaction flow field (117), anode outlet flow equalization transition zone (118), and anode fluid outlet (119).

2. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: A first insulating gasket (126) is provided between the left end pressure plate (101) and the left pole plate (102), and a second insulating gasket (127) is provided between the right end pressure plate (107) and the right pole plate (106).

3. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: A first sealing gasket (128) and a second sealing gasket (129) are respectively provided on both sides of the first membrane electrode (103) and the second membrane electrode (105). The first sealing gasket (128) is located on the cathode side of the first membrane electrode (103) and the second membrane electrode (105), and the second sealing gasket (129) is located on the anode side of the first membrane electrode (103) and the second membrane electrode (105).

4. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The left end pressure plate (101), left electrode plate (102), first membrane electrode (103), bipolar plate (104), second membrane electrode (105), first insulating gasket (126), first sealing gasket (128), and second sealing gasket (129) are respectively provided with a first liquid channel inlet (130), a first gas-liquid channel outlet (131), a second liquid channel inlet (132), and a second gas-liquid channel outlet (133). The first liquid channel inlet (130) and the first gas-liquid channel outlet (131) are respectively connected to the anode reaction chamber, and the second liquid channel inlet (132) and the second gas-liquid channel outlet (133) are respectively connected to the cathode reaction chamber.

5. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The cathode inlet flow equalization transition zone (111), cathode outlet flow equalization transition zone (113), anode inlet flow equalization transition zone (116), and anode outlet flow equalization transition zone (118) are respectively provided with L-shaped flow guide columns (120). The L-shaped flow guide columns (120) are located in the direction of the inlet or outlet of the reaction chamber, and the bent part of the L-shaped flow guide column (120) is arranged in the direction of fluid flow. The cathode inlet flow equalization transition zone (111) and cathode outlet flow equalization transition zone (113) are also provided with a group of transition flow equalization cylinders (121) located inside the L-shaped flow guide column (120).

6. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The cathode reaction flow field (112) consists of two vertical parallel channels (122), and a group of cathode flow field equalizing cylinders (123) for gas-liquid redistribution is arranged between the vertical parallel channels (122).

7. An industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The anodic reaction flow field (117) consists of three horizontal parallel flow channels (124), and a group of anodic flow equalization cylinders (125) for gas-liquid redistribution are arranged between the horizontal parallel flow channels (124).

8. The industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The first membrane electrode (103) and the second membrane electrode (105) are respectively composed of an anode electrode, an anion exchange membrane and a cathode electrode.

9. An industrial AEM hydrogen production electrolyzer according to claim 1, characterized in that: The materials of the left electrode plate (102), bipolar plate (104), and right electrode plate (106) are either nickel-plated stainless steel or pure nickel.

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