Low-impedance electrolysis cell of double-layer gas-liquid decoupling flow channel and electrolysis cell device

Abstract

The invention relates to a low-impedance electrolysis cell and an electrolysis cell device of a double-layer gas-liquid decoupling runner, the electrolysis cell comprises a cathode reaction electrode, an anode reaction electrode and a diaphragm arranged between the cathode reaction electrode and the anode reaction electrode, and a cathode side porous bipolar plate and an anode side porous bipolar plate are respectively arranged on two sides of the reaction electrodes. One side, deviating from the reaction electrode, of each porous bipolar plate is provided with a sunken concave area through machining, the sides, deviating from the reaction electrode, of the cathode side porous bipolar plate and the anode side porous bipolar plate are further provided with outer side main gas chambers, and pores are formed in the cathode side porous bipolar plate and the anode side porous bipolar plate in a penetrating manner. The bubble discharging efficiency is remarkably improved, the ohmic resistance of an electrolytic reaction area is reduced, and therefore the comprehensive performance of the electrolytic bath is greatly improved, and the service life of the electrolytic bath is greatly prolonged.

Description

Technical Field

[0001] This application relates to an innovative alkaline water electrolysis (AWE) hydrogen production device, specifically a low-impedance electrolysis chamber and electrolyzer device with a double-layer gas-liquid decoupled flow channel. Background Technology

[0002] Existing alkaline water electrolyzer technology suffers from a series of technical problems due to the "bubble effect," including reduced electrode active area, increased ohmic resistance, uneven current density distribution, localized overheating, and accelerated aging of catalysts and membranes. Summary of the Invention

[0003] The purpose of this application is to provide a low-impedance electrolysis chamber and electrolysis cell device with a double-layer gas-liquid decoupled flow channel, which significantly shortens the residence time of bubbles in the electrolysis reaction zone, thereby greatly improving the overall performance and service life of the electrolysis cell.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] In a first aspect, embodiments of this application provide a low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel, comprising a cathode reaction electrode, an anode reaction electrode, and a diaphragm placed between the two. A cathode-side porous bipolar plate and an anode-side porous bipolar plate are respectively disposed on both sides of the reaction electrode. On the side of each porous bipolar plate facing away from the reaction electrode, a sunken recessed area is formed by mechanical processing. An outer main gas chamber is also disposed on the side of the cathode-side porous bipolar plate and the anode-side porous bipolar plate facing away from the reaction electrode. The outer main gas chamber of the cathode-side porous bipolar plate and the recessed area of ​​the cathode-side porous bipolar plate constitute the cathode main gas chamber. The recessed area of ​​the body chamber and the porous bipolar plate on the anode side constitutes the anode main gas chamber. A full-flow channel structure is formed between the anode reaction electrode and the inner surface of the anode porous bipolar plate, constituting the anode secondary gas chamber. A full-flow channel structure is formed between the cathode reaction electrode and the inner surface of the cathode porous bipolar plate, constituting the cathode secondary gas chamber. Pores are provided through the porous bipolar plates on the cathode and anode sides, forming a fluid channel connecting the cathode secondary gas chamber and the cathode main gas chamber. Pores are also provided through the porous bipolar plate on the anode side, forming a fluid channel connecting the anode secondary gas chamber and the anode main gas chamber.

[0006] The perforations that are arranged through the porous bipolar plate on the cathode side and the porous bipolar plate on the anode side are circular pore arrays.

[0007] Gaskets are provided on the edges of the porous bipolar plates on the cathode and anode sides, as well as on both sides of the diaphragm, to achieve a reliable seal between the main gas chamber and the electrolyte flow channel.

[0008] The cathode reaction electrode uses a multilayer nickel wire mesh and is loaded with a Raney nickel or nickel-molybdenum alloy catalyst layer, while the anode reaction electrode uses a foamed nickel substrate and is loaded with a NiFe-LDH catalyst.

[0009] The pore arrays on the cathode-side porous bipolar plate and the anode-side porous bipolar plate are gradient-distributed along the height of the plate, with small or sparse pores at the bottom and large or dense pores at the top, in order to match the gas-liquid two-phase flow characteristics that increase gas generation along the path and to balance the pressure distribution.

[0010] A hydrogen-side electrolyte channel and an oxygen-side electrolyte channel are also provided between the cathode-side porous bipolar plate and the anode-side porous bipolar plate. A hydrogen-side electrolyte inlet is provided below the hydrogen-side electrolyte channel, and a hydrogen and electrolyte mixing outlet is provided above the hydrogen-side electrolyte channel. An oxygen-side electrolyte inlet is provided below the oxygen-side electrolyte channel, and an oxygen and electrolyte mixing outlet is provided above the oxygen-side electrolyte channel.

[0011] Secondly, embodiments of this application provide an electrolytic cell device composed of a low-impedance electrolytic cell with a double-layer gas-liquid decoupling flow channel, including the electrolytic cell as described above. The electrolytic cells are assembled in series to form the electrolytic cell device, and the recessed areas on the back of adjacent bipolar plates are combined back to back or closed by a partition.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] By innovating the physical structure of the bipolar plates, independent reaction and exhaust layers are constructed inside the electrolysis chamber, solving the gas resistance problem under high current density from a hardware structural perspective, and achieving compact structure and low ohmic resistance electrolysis operation. This reduces the ohmic internal resistance of the electrolyzer and lowers the electrolysis voltage. At the same current density, the structure of this invention has lower energy consumption or can support higher hydrogen production current densities at the same voltage, thereby improving the overall energy conversion efficiency. It can construct an efficient three-dimensional bubble exhaust path, significantly shortening the residence time of bubbles in the electrolysis reaction zone, thus greatly improving the comprehensive performance and service life of the electrolyzer. The electrolyte can undergo micro-convection heat exchange on both sides of the plates through dense pores, and the metal cavity at the back acts as efficient heat dissipation fins, eliminating localized overheating and improving the inherent safety of the device. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall structure of the electrolysis chamber according to an embodiment of this application;

[0016] Figure 2 This is a schematic diagram of the electrolysis chamber according to an embodiment of this application;

[0017] Figure 3 The bubble and electrolyte flow rate distribution in this embodiment of the application. Figure 1 ;

[0018] Figure 4 Bubble and electrolyte flow rate distribution in the embodiments of the application Figure 2 ;

[0019] Figure 5 This is a structural diagram of the cathode porous electrode plate according to an embodiment of this application;

[0020] Figure 6 This is a structural diagram of the anode porous electrode plate according to an embodiment of this application;

[0021] Figure 7 This is a structural diagram of the main gas chamber according to an embodiment of this application;

[0022] Figure 8 The simulation verification results of the conventional flow channel plate auxiliary gas chamber (A) and the novel porous plate flow channel auxiliary gas chamber (B) are shown in the embodiments of this application.

[0023] Figure 9 The diagram shows the bubble distribution in the main gas chamber (A) of the conventional flow channel plate and the main gas chamber of the novel porous plate flow channel, according to embodiments of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0025] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] like Figures 1-6As shown, this embodiment of the application provides a low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel, including a cathode reaction electrode 3, an anode reaction electrode 4, and a diaphragm 2 placed between them. A cathode-side porous bipolar plate 5 and an anode-side porous bipolar plate 6 are respectively disposed on both sides of the reaction electrode. On the side of each porous bipolar plate facing away from the reaction electrode, a sunken recessed area is formed by mechanical processing. An outer main gas chamber is also disposed on the side of the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6 facing away from the reaction electrode. The outer main gas chamber 7 of the cathode-side porous bipolar plate and the recessed area of ​​the cathode-side porous bipolar plate 5 constitute the cathode main gas chamber. The recessed area of ​​the side main gas chamber 8 and the anode side porous bipolar plate 6 constitutes the anode main gas chamber. A full-flow channel structure is formed between the anode reaction electrode 4 and the inner surface of the anode porous bipolar plate 6, constituting the anode auxiliary gas chamber. A full-flow channel structure is formed between the cathode reaction electrode 3 and the inner surface of the cathode porous bipolar plate 5, constituting the cathode auxiliary gas chamber. Pores are provided through the cathode side porous bipolar plate 5 and the anode side porous bipolar plate 6. The pores through the cathode side porous bipolar plate constitute the fluid channel connecting the cathode auxiliary gas chamber and the cathode main gas chamber. The pores through the anode side porous bipolar plate constitute the fluid channel connecting the anode auxiliary gas chamber and the anode main gas chamber.

[0027] The perforations that are arranged through the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6 are circular pore arrays.

[0028] The perforations that are arranged through the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6 are circular pore arrays.

[0029] Gaskets are provided on the edges of the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6, as well as on both sides of the diaphragm, to achieve a reliable seal between the main gas chamber and the electrolyte flow channel.

[0030] The cathode reaction electrode 3 is made of multilayer nickel wire mesh and loaded with Raney nickel or nickel-molybdenum alloy catalyst layer, while the anode reaction electrode 4 is made of foamed nickel substrate and loaded with NiFe-LDH catalyst.

[0031] The pore arrays on the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6 are gradient-distributed along the height of the plates, with small or sparse pores at the bottom and large or dense pores at the top, in order to match the gas-liquid two-phase flow characteristics that increase along the gas generation and to balance the pressure distribution.

[0032] A hydrogen-side electrolyte channel and an oxygen-side electrolyte channel are also provided between the cathode-side porous bipolar plate 5 and the anode-side porous bipolar plate 6. A hydrogen-side electrolyte inlet 11 is provided below the hydrogen-side electrolyte channel, and a hydrogen and electrolyte mixing outlet 9 is provided above the hydrogen-side electrolyte channel. An oxygen-side electrolyte inlet 12 is provided below the oxygen-side electrolyte channel, and an oxygen and electrolyte mixing outlet 10 is provided above the oxygen-side electrolyte channel.

[0033] This application provides an electrolytic cell device composed of a low-impedance electrolytic cell with a double-layer gas-liquid decoupling flow channel, including the electrolytic cell as described above. The electrolytic cells are assembled in series to form the electrolytic cell device, and the recessed areas on the back of adjacent bipolar plates are combined back to back or closed by a partition.

[0034] Please refer to Figure 2 Electrolyte and hydrogen bubbles flow out at outlet 105 on the cathode side of the porous bipolar plate; outlet 106 on the cathode side of the porous bipolar plate; outlet 107 on the anode side of the porous bipolar plate; outlet 108 on the anode side of the porous bipolar plate; inlet 109 on the anode side of the porous bipolar plate; inlet 110 on the anode side of the porous bipolar plate; inlet 111 on the cathode side of the porous bipolar plate; inlet 112 on the cathode side of the porous bipolar plate. The electrolyte flows at high speed throughout the entire channel, generating a strong shear force on the hydrogen and oxygen bubbles attached to the porous electrode network, causing them to detach rapidly. A small portion of the detached bubbles will flow out from the outlet on the side of the unit with the main electrolyte flow and enter the subsequent gas-liquid separator.

[0035] Vertical separation: Please refer to Figure 3 Hydrogen bubbles flow out of the pores towards 101; oxygen bubbles flow out of the pores towards 102; hydrogen bubbles are at 103; oxygen bubbles at 104. Because the main gas chamber is a relatively static low-pressure area, while the entire flow channel is a dynamic high-pressure area, this pressure difference drives most of the bubbles to pass through the pores on the porous bipolar plate and quickly enter the main gas chamber on the back of the bipolar plate. Figure 7 and Figure 8 The simulation comparison shows that, compared with the traditional structure (A), the structure of the present invention (B) has a very low bubble content in the reaction zone (sub-gas chamber), while the gas is efficiently collected into the main gas chamber.

[0036] like Figures 4 to 6 As shown, the cathode-side porous bipolar plate 5 is provided with a cathode auxiliary gas chamber 113 and a cathode full-flow channel structure 117, and the anode-side porous bipolar plate 6 is provided with an anode auxiliary gas chamber 114. The cathode main gas chamber of the cathode-side porous bipolar plate 3 and the anode main gas chamber of the anode-side porous bipolar plate 8 are collectively referred to as the main gas chamber 116. The main gas chamber 116 is provided with a main gas chamber outlet 115 for discharging hydrogen or oxygen.

[0037] The pure hydrogen and oxygen collected in the main gas chamber are led out of the electrolyzer through their respective independent gas outlet channels and enter the gas-liquid separation and purification system.

[0038] The reaction electrode is positioned close to the inner side of the electrode plate, eliminating the need for traditional flow guide ribs and creating a full-channel reaction space with no dead angles and low flow resistance between the electrode and the electrode plate, as well as within the electrode itself. The flow guide pores are distributed in a gradient along the height of the electrode plate, with smaller or sparser pores at the bottom and larger or denser pores at the top, to match the gas-liquid two-phase flow characteristics as the gas generation increases along the flow path and to balance the pressure distribution.

[0039] The core of this invention lies in the design of a composite functional porous bipolar plate. Unlike traditional solid bipolar plates, this plate is designed as a "sieve-like" through-body in its physical structure, with most of the solid material removed from its back side through precision machining, forming a deep cavity structure. When multiple chambers are stacked, this deep cavity, together with the frame of the adjacent unit, forms an independent main gas chamber located on the back side of the reaction zone. A small number of bubbles generated by the electrode reaction need to climb a long distance along the surface, but most of them enter the main gas chamber on the back side through the micropore array on the plate, taking the shortest path.

[0040] Embodiment 1 of this invention provides a low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel. Its core is a porous bipolar plate assembly made of pure nickel plate or nickel-plated stainless steel plate, with a single plate thickness of 3 mm. A rectangular recess with a depth of 2.0 mm is machined on the back side to form the main gas chamber. A solid frame with a width of 20 mm is retained around the perimeter for sealing and compression. The bottom wall of the recess has a thickness of 1.0 mm and is equipped with a circular through-pore array of φ1.5 mm. The pores are arranged in a triangular staggered pattern with a gradient porosity distribution along the height direction to accommodate the accumulation characteristics of bubbles in the vertical direction. The cathode uses a multi-layer nickel wire mesh loaded with a Raney nickel or nickel-molybdenum alloy catalyst layer, and the anode uses a foamed nickel substrate loaded with a NiFe-LDH catalyst. Both are directly bonded and fixed to the inner side of the bipolar plate, forming a full-channel auxiliary gas chamber with no guide ribs and low flow resistance. When multiple chambers are stacked, the recessed areas on the back of adjacent bipolar plates are combined back-to-back or sealed by partitions to form a spacious main gas chamber for gas collection. A PTFE sealing gasket is installed at the frame of the bipolar plate, and manifold holes are provided at the top and bottom ends, which are connected to the hydrogen and oxygen outlets and the electrolyte inlet through internal flow channels, respectively.

[0041] In Embodiment 2 of this application, the through-hole is changed to a conical hole with a larger inner diameter and a smaller outer diameter based on the above structure. The funnel-shaped structure enhances the collection and unidirectional discharge of bubbles. Furthermore, the gas-liquid separation and mass transfer performance is further improved by hydrophilic treatment of the reaction surface and gas-repellent treatment of the inside of the hole and the gas collection surface.

[0042] The electrolysis chamber of this invention has excellent modularity and is very suitable for building high-power electrolytic cell stacks.

[0043] A complete electrolytic cell stack is assembled by pressing together multiple electrolytic cells in series. The key is that adjacent electrolytic cells are separated by a shared porous bipolar plate.

[0044] For example, the back side of the porous bipolar plate on the anode side of the Nth unit is also the porous bipolar plate on the cathode side of the N+1th unit. This means that both sides of this shared bipolar plate need to be processed according to the requirements of this invention: one side is processed to form the anode main gas chamber for collecting oxygen, and the other side is processed to form the cathode main gas chamber for collecting hydrogen. The plate body is perforated to connect the two auxiliary gas chambers with the main gas chamber.

[0045] This integrated connection method significantly reduces the axial dimensions of the electrolyzer stack, achieving a highly compact structure. Simultaneously, the fluid ports (electrolyte inlet / outlet and gas outlet) can be connected via manifold channels on the bipolar plates and gaskets, forming the entire fluid distribution and collection system for the electrolyzer stack. This approach makes it possible to construct large-scale water electrolysis hydrogen production systems with uniform structure, consistent performance, and easy scalability.

[0046] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel, characterized in that, The device includes a cathode electrode, an anode electrode, and a diaphragm placed between them. A cathode-side porous bipolar plate and an anode-side porous bipolar plate are respectively disposed on both sides of the electrode. On the side of each porous bipolar plate facing away from the electrode, a sunken area is formed by mechanical processing. An outer main gas chamber is also disposed on the side of the cathode-side and anode-side porous bipolar plates facing away from the electrode. The outer main gas chamber of the cathode-side porous bipolar plate and the sunken area of ​​the cathode-side porous bipolar plate constitute the cathode main gas chamber. The outer main gas chamber of the anode-side porous bipolar plate and the sunken area of ​​the anode-side porous bipolar plate... The cathode and anode sides form a flow channel structure, which constitutes the anode main gas chamber. A full-flow channel structure is formed between the anode reaction electrode and the inner surface of the anode porous bipolar plate, constituting the anode secondary gas chamber. A full-flow channel structure is also formed between the cathode reaction electrode and the inner surface of the cathode porous bipolar plate, constituting the cathode secondary gas chamber. Pores are perforated through the cathode-side and anode-side porous bipolar plates, forming fluid channels connecting the cathode secondary gas chamber and the cathode main gas chamber. Similarly, perforations through the anode-side porous bipolar plate form fluid channels connecting the anode secondary gas chamber and the anode main gas chamber.

2. The low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel according to claim 1, characterized in that, The perforations that are arranged through the porous bipolar plate on the cathode side and the porous bipolar plate on the anode side are circular pore arrays.

3. The low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel according to claim 1, characterized in that, Gaskets are provided on the edges of the porous bipolar plates on the cathode and anode sides, as well as on both sides of the diaphragm, to achieve a reliable seal between the main gas chamber and the electrolyte flow channel.

4. The low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel according to claim 1, characterized in that, The cathode reaction electrode uses a multilayer nickel wire mesh and is loaded with a Raney nickel or nickel-molybdenum alloy catalyst layer, while the anode reaction electrode uses a foamed nickel substrate and is loaded with a NiFe-LDH catalyst.

5. The low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel according to claim 2, characterized in that, The pore arrays on the cathode-side porous bipolar plate and the anode-side porous bipolar plate are gradient-distributed along the height of the plate, with small or sparse pores at the bottom and large or dense pores at the top, in order to match the gas-liquid two-phase flow characteristics that increase gas generation along the path and to balance the pressure distribution.

6. The low-impedance electrolysis chamber with a double-layer gas-liquid decoupling flow channel according to claim 1, characterized in that, A hydrogen-side electrolyte channel and an oxygen-side electrolyte channel are also provided between the cathode-side porous bipolar plate and the anode-side porous bipolar plate. A hydrogen-side electrolyte inlet is provided below the hydrogen-side electrolyte channel, and a hydrogen and electrolyte mixing outlet is provided above the hydrogen-side electrolyte channel. An oxygen-side electrolyte inlet is provided below the oxygen-side electrolyte channel, and an oxygen and electrolyte mixing outlet is provided above the oxygen-side electrolyte channel.

7. An electrolytic cell device consisting of a low-impedance electrolytic chamber with a double-layer gas-liquid decoupling flow channel, characterized in that, Includes the electrolysis chambers as described in any one of claims 1-6, wherein the electrolysis chambers are assembled in series to form an electrolytic cell device, and the recessed areas on the back of adjacent bipolar plates are combined back to back or closed by a partition.

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