Novel PEM electrolytic bath with enhanced diffusion type flow channel structure

Abstract

The invention discloses a novel PEM electrolytic cell with an enhanced diffusion type flow channel structure, which comprises an electrolytic chamber structure, the electrolytic chamber structure is sequentially composed of a cathode plate, a cathode diffusion layer, a membrane electrode, an anode diffusion layer and an anode plate and is fixed through fasteners, and the surfaces of the adjacent sides of the anode plate and the cathode plate are provided with protruding structures to form a flow channel group. According to the novel PEM electrolytic bath, the protruding structures are arranged on the inner sides of the anode plate and the cathode plate to form the flow channel set, so that an electrolyte forms a directional flow path in the flow channel, the electrolyte is effectively guided to be distributed to the whole catalytic area, and local drying or concentration polarization is avoided. The flow channel structure provides a clear escape channel for generated hydrogen (cathode) and oxygen (anode), the residence time of bubbles on the surface of the catalyst is shortened, and ohmic impedance and overpotential are reduced. And the functional layers are connected by adopting fasteners, so that the assembly, disassembly and maintenance are convenient, and the device is suitable for a large-scale stacked PEM electrolytic cell system.

Description

Technical Field

[0001] This invention belongs to the field of new energy technology, and in particular relates to a novel PEM electrolyzer with an enhanced diffusion-type flow channel structure. Background Technology

[0002] Hydrogen production via water electrolysis is one of the most important parts of the hydrogen energy industry's development. The electrolysis chamber structure consists of a cathode plate, a cathode diffusion layer, a membrane electrode assembly (MEA), an anode diffusion layer, and an anode plate. Hydrogen and oxygen are generated at the catalyst in the MEA, but bubble formation hinders the interaction between the catalyst and the electrolyte, leading to an increase in the required voltage. In existing electrolyzers, bubbles rely solely on diffusion within the diffusion layer, resulting in slow bubble detachment. This is mitigated by increasing the electrolyte circulation flow rate, thereby increasing energy consumption.

[0003] Therefore, there is an urgent need to design an electrolytic cell to solve the problems mentioned above. Summary of the Invention

[0004] To address the technical problem mentioned in the background art, where bubbles in existing electrolyzers rely solely on diffusion within the diffusion layer, resulting in slow bubble detachment, a novel PEM electrolyzer with an enhanced diffusion-type flow channel structure is provided.

[0005] To achieve the above objectives, the specific technical solution of the novel PEM electrolyzer with an enhanced diffusion-type flow channel structure of the present invention is as follows: A novel PEM electrolyzer with an enhanced diffusion-type flow channel structure includes an electrolysis chamber structure, which is composed of a cathode plate, a cathode diffusion layer, a membrane electrode, an anode diffusion layer, and an anode plate in sequence and is fixed by fasteners. The surfaces of the anode plate and the cathode plate on adjacent sides are provided with protruding structures to form a flow channel assembly.

[0006] Furthermore, the flow channel assembly has an inlet on one side and an outlet on the other side. The flow channel assembly includes longitudinally spaced flow-limiting channels and a flow-collecting channel, the inlet of which is narrower than the outlet.

[0007] Furthermore, the flow channel assembly also includes an inlet flow channel and an outlet flow channel. The inlet flow channel is located at the lower part of the flow channel and is connected to the inlet end of each flow collection channel and flow restriction channel. The outlet flow channel is located at the upper part of the flow channel and is connected to the outlet end of each flow collection channel and flow restriction channel.

[0008] Furthermore, the inlet width of both the flow-limiting channel and the flow-collecting channel is 0.3mm-70mm, and the outlet width is also 0.3mm-70mm.

[0009] Furthermore, the sides of the flow-limiting channel and the flow-collecting channel are one of the following: straight line, broken line, circular arc, or spline curve.

[0010] Furthermore, the bottom of the flow-limiting channel and the flow-collecting channel is one of the following: a circular arc, a semi-circle, a hexagon, or a square.

[0011] Furthermore, the shape of the enhanced diffusion type electrode protruding structure is a beveled surface with rounded corners or chamfers, or the shape of the enhanced diffusion type electrode protruding structure is an arc surface with rounded corners or chamfers.

[0012] Furthermore, the direction of the inclined surface of the structure can be one of the following: uniform direction, symmetrical distribution starting from a certain flow channel, alternating at intervals, or randomly set.

[0013] Furthermore, the angle of inclination between the chord surface of the inclined or curved surface of the protruding structure and the plane of the electrode plate is 0.5°-60°.

[0014] Furthermore, a sealing ring is provided between the cathode plate and the cathode diffusion layer, and between the anode plate and the anode diffusion layer.

[0015] The novel PEM electrolyzer with enhanced diffusion-type flow channel structure of the present invention has the following advantages: This novel PEM electrolyzer forms a flow channel assembly by setting "protruding structures" on the inner sides of the anode and cathode plates, allowing the electrolyte to form a directional flow path within the flow channels. This effectively guides the electrolyte distribution throughout the entire catalytic region, avoiding localized drying or concentration polarization. The flow channel structure provides clear escape channels for the generated hydrogen (cathode) and oxygen (anode), reducing the residence time of bubbles on the catalyst surface and lowering ohmic impedance and overpotential. Fasteners are used to connect the functional layers, facilitating assembly, disassembly, and maintenance, making it suitable for large-scale stacked PEM electrolyzer systems. The protruding structures act as a supporting framework, enhancing the mechanical strength of the electrode plates and preventing deformation or leakage under high pressure differentials. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the components of the PEM electrolytic cell in this invention; Figure 2 This is a schematic diagram of the flow channel assembly in this invention; Figure 3 This is a schematic diagram of the protruding electrode structure in this invention; Figure 4 This is a schematic diagram of the installation of the electrode plate and gas diffusion layer in this invention; Figure 5 This is a schematic diagram comparing the power of an electrolytic cell according to an embodiment of the present invention and a commercial electrolytic cell.

[0017] Explanation of markings in the diagram: 101. Cathode plate; 102. Sealing ring; 103. Diffusion layer; 104. Membrane electrode; 105. Anode plate; 201. Liquid inlet; 202. Flow-limiting channel; 203. Flow-collecting channel; 204. Liquid outlet; 205. Liquid inlet channel; 206. Liquid outlet channel 301. Emphasize structure. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0022] The following is a reference to the appendix. Figure 1 To be continued Figure 5 This invention describes a novel PEM electrolyzer with an enhanced diffusion-type flow channel structure.

[0023] This embodiment provides a novel PEM electrolyzer with an enhanced diffusion-type flow channel structure. Figure 1 This is a schematic diagram of the components of the PEM electrolytic cell in this invention; as shown. Figure 1 As shown, the novel PEM electrolyzer includes an electrolysis chamber structure, which is composed of a cathode plate 101, a cathode diffusion layer 103, a membrane electrode 104, an anode diffusion layer 103, and an anode plate 105 in sequence and is fixed by fasteners. The anode plate 105 and the cathode plate 101 are provided with protruding structures 301 on adjacent side surfaces to form a flow channel group.

[0024] Understandably, this novel PEM electrolyzer utilizes a flow channel assembly formed by protruding structures 301 on the inner sides of the anode plate 105 and cathode plate 101. This allows the electrolyte to form a directional flow path within the channels, effectively guiding its distribution throughout the catalytic region and preventing localized drying or concentration polarization. The flow channel structure provides clear escape routes for the generated hydrogen (cathode) and oxygen (anode), reducing the residence time of bubbles on the catalyst surface and lowering ohmic impedance and overpotential. Fasteners are used to connect the functional layers, facilitating assembly, disassembly, and maintenance, making it suitable for large-scale stacked PEM electrolyzer systems. The protruding structures 301 act as a supporting framework, enhancing the mechanical strength of the plates and preventing deformation or leakage under high pressure differentials.

[0025] Furthermore, Figure 2 This is a schematic diagram of the flow channel assembly; such as Figure 2 As shown, the flow channel group has an inlet 201 on one side and an outlet 204 on the other side. The flow channel group includes longitudinally spaced flow-limiting channels 202 and a flow-collecting channel 203. The inlet 201 of the flow-collecting channel 203 is narrower than the outlet 204.

[0026] Understandably, the "narrow inlet, wide outlet" design of the flow collector 203 creates a gradually expanding channel, causing the fluid pressure to gradually decrease and the velocity to slow down after entry, which is conducive to the liquid diffusion to both sides and improves the overall wettability of the membrane electrode 104. The flow restrictor 202 controls the flow rate per unit area, preventing overflow or underflow in some areas; combined with the synergistic effect of the flow collector 203, it achieves a dynamic balance between the main flow channel and the branch flow channels. The increased flow velocity at the narrow inlet generates a local turbulence effect, which helps to break the boundary layer and improve the mass transfer rate. The inlet and outlet 204 are located on opposite sides, forcing the electrolyte to flow through the entire flow field, significantly reducing the risk of stagnant areas and bubble accumulation.

[0027] Furthermore, such as Figure 2 As shown, the flow channel group also includes an inlet flow channel 205 and an outlet flow channel 206. The inlet flow channel 205 is located at the lower part of the flow channel and is connected to the inlet end of each flow collecting channel 203 and flow limiting channel 202. The outlet flow channel 206 is located at the upper part of the flow channel and is connected to the outlet end of each flow collecting channel 203 and flow limiting channel 202.

[0028] Understandably, the lower inlet channel 205 provides unified liquid supply, while the upper outlet channel 206 centrally discharges and exhausts water, forming a vertical circulation system of "bottom inlet, top outlet." Utilizing buoyancy to assist gas-liquid separation significantly improves exhaust efficiency. The shared main inlet channel 205 ensures consistent initial pressure across all sub-channels, avoiding uneven flow rates due to path differences and improving the consistency of current density distribution. Multiple channels converge through shared inlets and outlets, reducing the number of external interfaces and lowering sealing complexity and leakage risk. This structure supports high-flow-rate circulation and maintains good heat dissipation and material transport performance even under high current density conditions.

[0029] Furthermore, the inlet width of the flow-limiting channel 202 and the inlet width of the flow-collecting channel 203 are both 0.3mm-70mm, and the outlet width is also 0.3mm-70mm.

[0030] Understandably, a width range of 0.3–70 mm covers microchannels to conventional flow channel scales, allowing for flexible design based on different electrolytic cell power levels to meet application needs from pilot-scale equipment to industrial-grade systems. Smaller widths (e.g., 0.3–2 mm) are used for high-precision control of flow rate and shear force, facilitating microbubble removal; larger widths (e.g., 10–70 mm) are suitable for low-resistance main channels, ensuring overall flowability. This range is suitable for precision machining processes (such as stamping and etching) while achieving efficient mass transfer while maintaining structural strength. A minimum width of 0.3 mm maintains a certain flow rate while preventing complete blockage caused by impurity particles.

[0031] Furthermore, the sides of the flow-limiting channel 202 and the flow-collecting channel 203 are one of the following: straight line, broken line, circular arc or spline curve.

[0032] Understandably, curves or splines can eliminate vortex dead zones caused by right-angle bends, improving fluid coverage. Circular arcs or spline transitions reduce local drag losses, improving energy efficiency. Multiple geometric shapes support numerical simulations to select the optimal configuration, accelerating product iteration.

[0033] It should be noted that different sidewall shapes can induce different flow patterns. For example, straight flow-limiting channels 202 and flow-collecting channels 203 can stabilize laminar flow and are suitable for low-energy consumption scenarios; broken-line flow-limiting channels 202 and flow-collecting channels 203 can generate periodic vortices and enhance mixing. In short, different types of flow-limiting channels 202 and flow-collecting channels 203 have different applicable fields. In the application process, the staff can select the appropriate type of flow-limiting channel 202 and flow-collecting channel 203 according to the actual situation. This embodiment does not make specific limitations.

[0034] Furthermore, the bottom ends of the flow-limiting channel 202 and the flow-collecting channel 203 are one of the following: arc, semicircle, hexagon, or square.

[0035] Understandably, different bottom shapes alter the effective contact area between the diffusion layer 103 and the flow channel, thereby regulating the local electron conduction path and improving the uniformity of the electrochemical reaction. Hexagonal or square structures have higher structural rigidity and stronger resistance to water pressure fluctuations. Different bottom shapes are adaptable to different manufacturing methods such as stamping, injection molding, and 3D printing, improving industrialization feasibility.

[0036] It should be noted that the curved or semi-circular bottom has the advantage of smooth curvature, which can reduce the number of points where bubbles attach and facilitate the sliding and detachment of bubbles along the curved surface. On the other hand, the square or hexagonal bottom is prone to forming local low-pressure areas at the corners, which can easily induce bubbles to break or detach prematurely.

[0037] Furthermore, Figure 3 This is a schematic diagram of the protruding electrode structure; Figure 4 A schematic diagram showing the installation of the electrode plate and gas diffusion layer; as shown. Figure 3 and Figure 4 As shown, the shape of the enhanced diffusion type electrode protrusion structure 301 is a beveled surface with rounded corners or chamfers, or the shape of the enhanced diffusion type electrode protrusion structure 301 is an arc surface with rounded corners or chamfers.

[0038] Understandably, the "sloping" or "arc" structure creates a guide wing effect, promoting electrolyte flow along the catalyst wall, increasing the fluid sweep frequency, and enhancing the reactant supply rate. The sloping or arc-shaped surface reduces bubble adhesion, using fluid shear force to propel bubbles rapidly away from the catalyst layer, reducing the shading effect. Rounded or chamfered edges eliminate sharp edges, improving structural fatigue life and preventing cracking during long-term operation. The sloping / arc structure creates a non-uniform but controllable pressure gradient during compression, which is beneficial for gas and liquid two-phase transport.

[0039] Furthermore, the inclined plane of the prominent structure 301 can be one of the following: a uniform direction, a symmetrical distribution starting from a certain flow channel, an alternating arrangement, or a random arrangement.

[0040] Understandably, directional arrangement actively intervenes in the bubble's trajectory to prevent it from agglomerating into large bubbles that hinder the reaction. Multiple arrangement options allow for the customization of optimal flow field structures for different operating conditions (such as voltage, temperature, and flow rate). This ensures the rational distribution of fluid kinetic energy, avoiding excessive cooling or heating in certain areas.

[0041] It should be noted that in practical applications, the flow field organization can be adjusted according to different structural characteristics. For example, a unified direction can form a unidirectional mainstream, suitable for simple and efficient liquid distribution; a centrally symmetrical layout can achieve bidirectional confluence, improving the utilization rate of the central area; alternating flow directions can induce lateral disturbances, break the boundary layer, and enhance mixing; random settings can simulate natural flow states and reduce resonance or flow deviation caused by regular structures. Therefore, in practical applications, staff can set the flow field reasonably according to the situation, and this embodiment does not impose specific limitations.

[0042] Furthermore, the angle of inclination between the chord surface of the inclined or curved surface of the protruding structure 301 and the plane of the electrode plate is 0.5°-60°.

[0043] Understandably, while an excessively large angle enhances disturbance, it also increases pump consumption; this range achieves a good trade-off between performance improvement and energy consumption. The tilt angle can be matched to the GDL (gas diffusion layer 103) compression, ensuring good electrical contact while preserving sufficient flow channel space. This angle is a key parameter for the co-design of fluid dynamics, electrochemistry, and structural mechanics.

[0044] It should be noted that small angles of 0.5°–10° can gently guide the flow, suitable for sensitive materials or low flow conditions; medium angles of 10°–45° have a strong shearing effect, significantly promoting bubble detachment; and large angles of 45°–60° can strongly disturb the flow, suitable for rapid defoaming under high gas production rates.

[0045] Furthermore, a sealing ring 102 is provided between the cathode plate 101 and the cathode diffusion layer 103, and between the anode plate 105 and the anode diffusion layer 103.

[0046] Understandably, this effectively isolates the hydrogen and oxygen sides, preventing hydrogen from mixing with oxygen or vice versa, ensuring gas purity (especially crucial for hydrogen safety). It maintains a reliable seal even under high-pressure cycling conditions, preventing corrosive liquids from leaking and damaging peripheral components. The sealing ring 102 has elastic deformation capabilities, compensating for microscopic unevenness between the electrode plate and the diffusion layer 103, ensuring complete sealing integrity. Made of acid- and alkali-resistant, oxidation-resistant materials, the sealing ring 102 can operate stably for extended periods in PEM strong acid environments. Compared to welding or bonding, the structure of the sealing ring 102 facilitates periodic replacement of the diffusion layer 103 or the membrane electrode 104.

[0047] Figure 5 This is a schematic diagram comparing the power of the electrolytic cell in this embodiment and a commercial electrolytic cell, as shown below. Figure 5 As shown in the figure, the characteristics of novel and commercial PEM electrolyzers within a voltage range of 0–1.8V were studied through experiments at an electrolyte temperature of 70℃. The experimental results are as follows. Figure 3As shown, the current density of both novel and commercial PEM electrolyzers increases with increasing voltage. When the voltage exceeds 1.4V, the current density growth rate of the novel PEM electrolyzer begins to exceed that of the commercial PEM electrolyzer.

[0048] The experimental results show that, under high voltage conditions, the performance of the novel PEM electrolyzer with its irregularly shaped flow channel structure is significantly superior to that of commercial PEM electrolyzers. Under high voltage conditions, the electrolyzer generates a large amount of gas, and the oxygen in this gas accumulates in the flow channel on the anode side, hindering the diffusion of the electrolyte to the membrane electrode 104. However, the PEM electrolyzer in this embodiment employs an enhanced diffusion electrode structure. This structure effectively promotes the discharge of hydrogen and oxygen from the flow channel, significantly reducing the thickness of the hydrogen and oxygen layers, thereby increasing the diffusion effect of the electrolyzer and reducing the reaction resistance of the system. Therefore, this novel PEM electrolyzer with its irregularly shaped flow channel structure exhibits higher current density and power.

[0049] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A novel PEM electrolyzer with an enhanced diffusion-type flow channel structure, characterized in that, It includes an electrolysis chamber structure, which consists of a cathode plate, a cathode diffusion layer, a membrane electrode, an anode diffusion layer, and an anode plate in sequence and is fixed by fasteners. The surfaces of the anode plate and the cathode plate on adjacent sides are provided with protruding structures to form a flow channel group.

2. The novel PEM electrolytic cell according to claim 1, characterized in that, The flow channel assembly has an inlet on one side and an outlet on the other side. The flow channel assembly includes longitudinally spaced flow-limiting channels and a flow-collecting channel. The inlet of the flow-collecting channel is narrower than the outlet.

3. The novel PEM electrolytic cell according to any one of claims 1 or 2, characterized in that, The flow channel assembly also includes an inlet flow channel and an outlet flow channel. The inlet flow channel is located at the bottom of the flow channel and is connected to the inlet end of each flow collection channel and flow restriction channel. The outlet flow channel is located at the top of the flow channel and is connected to the outlet end of each flow collection channel and flow restriction channel.

4. The novel PEM electrolytic cell according to any one of claims 2 or 3, characterized in that, The inlet width of both the flow-limiting channel and the flow-collecting channel is 0.3mm-70mm, and the outlet width is also 0.3mm-70mm.

5. The novel PEM electrolytic cell according to any one of claims 2 or 3, characterized in that, The sides of the flow-limiting channel and the flow-collecting channel are one of the following: straight line, broken line, circular arc or spline curve.

6. The novel PEM electrolytic cell according to any one of claims 2 or 3, characterized in that, The bottom of the flow-limiting channel and the flow-collecting channel is one of the following: arc, semicircle, hexagon or square.

7. The novel PEM electrolytic cell according to claim 1, characterized in that, The shape of the enhanced diffusion type electrode protruding structure is a beveled surface with rounded corners or chamfers, or the shape of the enhanced diffusion type electrode protruding structure is an arc surface with rounded corners or chamfers.

8. The novel PEM electrolytic cell according to claim 7, characterized in that, The direction of the prominent structural slope can be one of the following: uniform direction, symmetrical distribution starting from a certain flow channel, alternating at intervals, or randomly set.

9. The novel PEM electrolytic cell according to claim 7, characterized in that, The angle of inclination between the chord surface of the inclined or curved surface of the protruding structure and the plane of the electrode plate is 0.5°-60°.

10. The novel PEM electrolytic cell according to claim 1, characterized in that, A sealing ring is provided between the cathode plate and the cathode diffusion layer, and between the anode plate and the anode diffusion layer.

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