Space proton exchange membrane electrolytic tank with porous graphene micro-channel structure

Abstract

The invention provides a space proton exchange membrane electrolytic tank with a porous graphene micro-channel structure, and belongs to the technical field of space energy and hydrogen production through water electrolysis. The problems that a traditional electrolytic tank is large in runner resistance, limited in ion migration, complex in structure and large in occupied space are solved. The bipolar plate comprises two bipolar plates, wherein a cavity is formed inside after the two bipolar plates are combined; the proton exchange membrane is arranged between the contact surfaces of the two bipolar plates and divides the cavity into two chambers, each chamber is filled with a porous graphene structure and forms two flow channels, and generated gas flows along the wall surface in pores formed by a framework between the adjacent porous graphene structures. The catalyst layers cover the two sides of the proton exchange membrane, and the catalyst layer on each side is connected with the porous graphene structure on the same side. The device is mainly used for providing a gas-liquid flowing channel.

Description

Technical Field

[0001] The present invention belongs to the technical fields of space energy and hydrogen production by electrolysis of water, and particularly relates to a space proton exchange membrane electrolytic cell with a porous graphene microchannel structure. Background Art

[0002] In special application scenarios such as aerospace and space stations, the weight of the device directly affects the economy and feasibility of the mission. The traditional metal flow channels or thick carbon-based flow channels have a high weight, a large mass transfer resistance to the electrolyte, limited ion migration, increased energy consumption, and shortened service life. In addition, the traditional flow channel structure is complex, occupies a large space, is not conducive to the miniaturization and integration development of the electrolytic cell, and is difficult to meet the requirements of modern industry for efficient and compact electrolytic equipment.

[0003] As a two-dimensional single-layer honeycomb lattice material composed of carbon atoms, porous graphene has a carrier mobility much higher than that of traditional carbon materials, and has advantages such as high porosity, low density, and large specific surface area. It can significantly reduce ohmic loss, improve the overall efficiency of the electrolytic cell, and its density is much lower than that of metal materials, which can significantly reduce the weight of the equipment, reduce the demand for pumping power, thereby saving energy consumption. Especially in the space environment, energy conservation is particularly crucial and it is especially suitable for the space and aerospace fields.

[0004] Through the technology of 3D printing the porous graphene structure, a porous graphene flow channel with high porosity and uniform pore size distribution can be prepared to optimize the mass transfer and gas emission performance.

[0005] Based on the above background, the present invention significantly improves the electrolysis efficiency and durability of the device by optimizing the flow channel structure and material properties, and at the same time realizes a lightweight design. It can effectively address the core bottlenecks in traditional designs and is applicable to ground renewable energy hydrogen production scenarios, as well as the special needs of aerospace and space exploration.

[0006] In summary, a space proton exchange membrane electrolytic cell with a porous graphene microchannel structure is proposed. Summary of the Invention

[0007] In view of this, the present invention aims to provide a space proton exchange membrane electrolytic cell with a porous graphene microchannel structure to solve the problems of large flow channel resistance, limited ion migration, and complex structure occupying a large space in traditional electrolytic cells.

[0008] To achieve the above object, the present invention adopts the following technical solutions to provide a space proton exchange membrane electrolytic cell with a porous graphene microchannel structure, including: Bipolar plates, a cavity is formed inside after two of the bipolar plates are combined; The proton exchange membrane is disposed between the contact surfaces of the two bipolar plates and divides the cavity into two chambers. Each chamber is filled with a porous graphene structure to form two flow channels. The porous graphene structure has a continuous hierarchical pore distribution structure inside, and the generated gas diffuses and flows along the pore walls in the flow channels; The catalyst layers cover both sides of the proton exchange membrane, and each catalyst layer on each side is coupled with the porous graphene structure on the same side.

[0009] Furthermore, the porous graphene structure is a three-dimensional single-layer honeycomb lattice material.

[0010] Furthermore, the pore diameter of the porous graphene structure is 40 - 120 PPI, and the porosity is 95%.

[0011] Furthermore, the two bipolar plates are respectively connected to the positive and negative electrodes of the power supply to form an anode-side plate and a cathode-side plate. The flow channel corresponding to the anode-side plate is the oxygen flow channel, and the flow channel corresponding to the cathode-side plate is the hydrogen flow channel.

[0012] Furthermore, the anode-side plate is provided with a water inlet and an oxygen outlet. The water inlet and the oxygen outlet are communicated through the oxygen flow channel. The cathode-side plate is provided with a hydrogen outlet, and the hydrogen outlet is communicated with the hydrogen flow channel.

[0013] Furthermore, the water inlet and the oxygen outlet are located on the same surface of the anode-side plate.

[0014] Furthermore, the water inlet and the oxygen outlet are centrosymmetric about the center of the anode-side plate.

[0015] Furthermore, the hydrogen outlet and the oxygen outlet are symmetrically arranged with the proton exchange membrane as the symmetry plane.

[0016] Furthermore, the hydrogen flow channel and the oxygen flow channel are symmetrically arranged with the proton exchange membrane as the symmetry plane.

[0017] Furthermore, the anode-side plate, the cathode-side plate, the proton exchange membrane and the catalyst layers are hermetically arranged.

[0018] Beneficial effects: 1. The three-dimensional structure of the porous material with a pore diameter between several micrometers and dozens of micrometers shows good hydrophilicity and water absorption as a whole under specific porosity and aperture ratio conditions, while also taking into account good electrical and thermal conductivity. When water contacts this material, it can instantaneously absorb water through "capillary action" and diffuse along the surface between the tiny pores into the porous material structure, reducing the mass transfer resistance and solving the problem of limited ion migration.

[0019] Due to the lightweight design and high-performance characteristics of graphene materials, the overall manufacturing and operating costs of the device are reduced, making it suitable for special application scenarios such as aerospace and space stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic diagram of the overall structure of the spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to the present invention; Figure 2 is an exploded view of the flow channel of the spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to the present invention; Figure 3 is a schematic diagram of the assembly structure of the graphene porous flow channel plate and the membrane electrode assembly of the spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to the present invention; Figure 4 is a schematic diagram of the manufacturing process of the porous graphene microchannel of the spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to the present invention.

[0021] In the figure: oxygen outlet 1; water inlet 2; anode catalyst layer 3; proton exchange membrane 4; cathode catalyst layer 5; hydrogen outlet 6; hydrogen flow channel 7A; oxygen flow channel 7B; power supply 8; inlet straight groove portion 9A; outlet straight groove portion 9B; cathode side plate 10A; anode side plate 10B. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention may be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0023] It should be noted that the descriptions of directions such as "left", "right", "left side", "right side", "upper part", "lower part", "top", "bottom" in the present invention are defined based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the structure must be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. In the description of the present invention, "a plurality" means more than two, unless otherwise specifically defined.

[0024] In the description of the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Referring to the accompanying drawings to illustrate this embodiment, a spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure is provided, including: Bipolar plates 10, an internal cavity is formed after two of the bipolar plates 10 are combined; A proton exchange membrane 4, which is arranged between the contact surfaces of the two bipolar plates 10 and divides the cavity into two chambers. Each chamber is filled with a porous graphene structure and forms two flow channels. The porous graphene structure has a continuous hierarchical pore distribution structure inside, and the generated gas diffuses and flows along the pore wall surfaces in the flow channels; Catalyst layers, which cover both sides of the proton exchange membrane 4, and each catalyst layer on each side is coupled with the porous graphene structure on the same side.

[0026] Deionized water enters the flow channels, oxygen and hydrogen are generated in the catalyst layers. The two adjacent flow channels do not directly contact each other, and the gas flows along the wall surfaces in the pores formed by the skeletons between the adjacent porous graphene structures; when the reaction gas passes through the flow channels of the porous graphene, diffusion in the horizontal and vertical directions and in the direction perpendicular to the plate towards the membrane electrode occurs, thereby effectively improving the distribution uniformity of the reaction gas and improving the drainage and exhaust effects of the flow channels.

[0027] In this embodiment, the porous graphene structure is a three-dimensional single-layer honeycomb lattice material.

[0028] The flow channels are all porous graphene flow channels, which are formed by the wall surfaces of the porous graphene medium. The porous graphene material has a three-dimensional structure with a pore diameter between several micrometers and dozens of micrometers.

[0029] In this embodiment, the pore diameter of the porous graphene structure is 40 - 120 PPI, and the porosity is 95%.

[0030] In this embodiment, the two bipolar plates 10 are respectively connected to the positive and negative electrodes of the power supply 8 to form an anode-side plate 10B and a cathode-side plate 10A. The flow channel corresponding to the anode-side plate 10B is an oxygen flow channel 7B, and the flow channel corresponding to the cathode-side plate 10A is a hydrogen flow channel 7A.

[0031] In this embodiment, the anode-side plate 10B is provided with a water inlet 2 and an oxygen outlet 1. The water inlet 2 and the oxygen outlet 1 are communicated through the oxygen flow channel 7B. The cathode-side plate 10A is provided with a hydrogen outlet 6, and the hydrogen outlet 6 is communicated with the hydrogen flow channel 7A.

[0032] Inside the bipolar plate, there are an inlet straight groove portion 9A and an outlet straight groove portion 9B. After the external deionized water flows into the flow channel through the inlet straight groove portion 9A, through the reaction in the catalyst layer plate, hydrogen or oxygen is generated and combined with the deionized water to form a gas-liquid two-phase flow. The gas-liquid two-phase flow flows out of the flow channel through the outlet straight groove portion 9B. The catalyst layer includes an anode catalyst layer 3 and a cathode catalyst layer 5. The anode catalyst layer 3 is located on the side of the anode-side plate 10B and generates oxygen. The cathode catalyst layer 5 is located on the side of the cathode-side plate 10A and generates hydrogen. The specific materials of the anode catalyst layer 3 and the cathode catalyst layer 5 can adopt the existing technologies and will not be elaborated here.

[0033] The inlet straight groove portion 9A of the anode-side plate 10B is communicated with the water inlet 2, and the outlet straight groove portion 9B of the anode-side plate 10B is communicated with the oxygen outlet 1; the outlet straight groove portion 9B of the cathode-side plate 10A is communicated with the hydrogen outlet.

[0034] In this embodiment, the water inlet 2 and the oxygen outlet 1 are located on the same surface of the anode-side plate 10B.

[0035] In this embodiment, the water inlet 2 and the oxygen outlet 1 are centrosymmetric with respect to the center of the anode-side plate 10B.

[0036] According to the shape of the bipolar plate, the water inlet 2 and the oxygen outlet 1 can be at the farthest relative positions on the anode-side plate 10B, increasing the flow distance of the gas-liquid in the flow channel, enabling the deionized water to fully contact the catalyst layer, and promoting the generation of gas.

[0037] In this embodiment, the hydrogen outlet 6 and the oxygen outlet 1 are symmetrically arranged with the proton exchange membrane 4 as the symmetry plane.

[0038] Similarly, according to the shape of the bipolar plate, the hydrogen outlet 6 and the water inlet 2 are set at a relatively far distance, increasing the flow distance of the gas-liquid in the flow channel, enabling the deionized water to fully contact the catalyst layer, and promoting the generation of gas.

[0039] In this embodiment, the hydrogen flow channel 7A and the oxygen flow channel 7B are symmetrically arranged with the proton exchange membrane 4 as the symmetry plane.

[0040] Sealing grooves are provided around all the water inlets 2, oxygen outlets 1, hydrogen outlets 6, oxygen flow channels 7B and hydrogen flow channels 7A of the bipolar plate, which is beneficial to maintaining the relative seal between the inside and the outside.

[0041] In this embodiment, the anode-side plate 10B, the cathode-side plate 10A, the proton exchange membrane 4, and the catalyst layer are hermetically sealed, which is beneficial to maintaining the internal sealing performance.

[0042] Deionized water flows in from the water inlet 2, passes through the anode-side plate 10B and enters the oxygen flow channel 7B of the porous graphene material. Under the catalytic action of the anode catalyst layer 3, it decomposes to generate oxygen and H ＋ protons. The oxygen is discharged from the electrolytic cell through the oxygen outlet 1 along with the remaining unreacted water, while the protons pass through the proton exchange membrane 4 in the form of hydrated protons to reach the cathode. Under the catalytic action of the cathode catalyst layer 5, hydrogen is synthesized, permeates through the hydrogen flow channel 7A of the porous graphene material, and is discharged from the hydrogen outlet 6 carrying a small amount of moisture.

[0043] Preparation process of the porous graphene material: Based on the disadvantage of insufficient viscosity of pure graphene ink, the present invention adopts the method of mixing polymer 3D printing graphene. The polymer solution (such as GO, SiC, etc.) is mixed with the graphite suspension to form 3D printing ink. A specific pattern with a certain thickness is 3D printed through a nozzle, and after printing, steps such as light irradiation, heat treatment, and freeze-drying are carried out for curing to retain the shape and the characteristics of the porous graphene and enhance the mechanical properties of the graphene material.

[0044] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention.

Claims

1. A spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure, characterized in that: include: A bipolar plate (10), wherein two bipolar plates (10) are combined to form a cavity inside; A proton exchange membrane (4) is arranged between the two bipolar plates (10) and divides the cavity into two chambers, each of the chambers is filled with a porous graphene structure to form a flow channel, the porous graphene structure has a continuous hierarchical pore distribution structure inside, and the generated gas diffuses and flows along the wall of the pores in the flow channel; The catalyst layer covers both sides of the proton exchange membrane (4), and the catalyst layer on each side is coupled with the porous graphene structure on the same side.

2. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to claim 1, characterized in that: The porous graphene structure is a three-dimensional single-layer honeycomb lattice material.

3. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to claim 1, characterized in that: The pore size of the porous graphene structure is 40-120 PPI, and the porosity is 95%.

4. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to claim 1, characterized in that: The two bipolar plates (10) are respectively connected to the positive and negative electrodes of a power source (8) to form an anode side plate (10B) and a cathode side plate (10A); the flow channel corresponding to the anode side plate (10B) is an oxygen flow channel (7B), and the flow channel corresponding to the cathode side plate (10A) is a hydrogen flow channel (7A).

5. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to claim 4, characterized in that: The anode side plate (10B) is provided with a water inlet (2) and an oxygen outlet (1), the water inlet (2) and the oxygen outlet (1) are connected via the oxygen flow channel (7B), and the cathode side plate (10A) is provided with a hydrogen outlet (6), the hydrogen outlet (6) is connected to the hydrogen flow channel (7A).

6. The spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to claim 5, characterized in that: The water inlet (2) and the oxygen outlet (1) are located on the same surface of the anode side plate (10B).

7. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to claim 6, characterized in that: The water inlet (2) and the oxygen outlet (1) are centrally symmetrical about the center of the anode side plate (10B).

8. The spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to claim 5, characterized in that: The hydrogen outlet (6) and the oxygen outlet (1) are symmetrically arranged with the proton exchange membrane (4) as a symmetry plane.

9. The spatial proton exchange membrane electrolytic cell with a porous graphene microchannel structure according to claim 5, characterized in that: The hydrogen flow channel (7A) and the oxygen flow channel (7B) are symmetrically arranged with the proton exchange membrane (4) as a symmetry plane.

10. The spatial proton exchange membrane electrolyzer with a porous graphene microchannel structure according to any one of claims 5 to 9, characterized in that: The anode side electrode plate (10B), the cathode side electrode plate (10A), the proton exchange membrane (4) and the catalyst layer are arranged in a sealed manner.

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