A proton exchange membrane electrolysis cell with a structure of a slant wall barb reinforced defoaming runner
By employing a sloping-walled barbed structure to enhance the degassing flow channel in a proton exchange membrane electrolyzer, the problems of bubble retention and increased pressure drop under traditional flow channel structures are solved, thereby improving the uniformity of gas-liquid distribution and the performance of the electrolyzer, making it suitable for engineering manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI UNIV OF ENG SCI
- Filing Date
- 2026-04-10
- Publication Date
- 2026-06-23
Smart Images
Figure CN122256992A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of proton exchange membrane electrolysis for hydrogen production, and in particular to a proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure. Background Technology
[0002] Proton exchange membrane (PEM) water electrolysis for hydrogen production has significant application value in renewable energy hydrogen production and distributed hydrogen production due to its advantages such as high current density, fast response speed, and high gas purity. In the PEM electrolyzer structure, the flow channel design of the bipolar plate or flow field plate directly affects water distribution, gas production and discharge, mass transfer efficiency, and the overall voltage drop and energy consumption level of the battery.
[0003] In existing technologies, flow channel structures typically employ rectangular cross-section straight flow channels, serpentine flow channels, or multi-channel parallel flow channel structures. Among these, rectangular cross-section flow channels (such as 2mm×2mm square flow channels) are widely used in laboratory and engineered electrolytic cell structures due to their simple processing and low resistance loss. However, under high current density operating conditions, a large number of oxygen bubbles are generated on the anode side and adhere to the electrode surface and flow channel walls, easily forming bubble stagnation zones, causing reaction and energy consumption problems.
[0004] In existing technologies, to improve the bubble discharge effect, some solutions use serpentine flow channels to enhance turbulence or reduce the flow channel size to increase flow velocity shear force. However, the above methods usually significantly increase pressure drop. Other technologies enhance gas-liquid separation by setting turbulence structures or protrusions inside the flow channel. However, common structures are mostly arranged at the bottom or top plane of the flow channel, which easily increases the processing difficulty and has a significant impact on the mainstream resistance.
[0005] Therefore, under the premise of ensuring that the overall hydraulic diameter of the flow channel is comparable to that of the traditional 2mm×2mm rectangular flow channel and avoiding a significant increase in pressure drop, how to improve the bubble desorption efficiency and mass transfer performance by optimizing the flow channel cross-sectional structure and wall microstructure design remains a technical problem that urgently needs to be solved in this field.
[0006] The existing technical solution is to use a straight or parallel flow channel structure with a regular cross section in the bipolar plate or flow field plate of the proton exchange membrane electrolyzer. The flow channel cross section is mostly rectangular or trapezoidal to improve fluid distribution and structural strength.
[0007] A typical implementation scheme is as follows: (1) Rectangular straight flow channel structure The most common flow channel cross-section in existing technologies is a rectangular structure. Its construction features a base plate and two straight side walls, with a closed space at the top formed by the upper surface of the bipolar plate or a cover plate. The flow channels are arranged parallel to each other, and water flows unidirectionally along the channel axis. The generated gas forms a gas-liquid two-phase flow with the water inside the channel. This structure is simple to manufacture and has a low pressure drop, but the walls are smooth planes, lacking functional structures to promote bubble desorption. Bubbles easily form stagnation zones between the electrodes and the walls.
[0008] (2) Trapezoidal or inverted trapezoidal flow channel structure To enhance mechanical strength or improve gas-liquid distribution, some existing technologies employ trapezoidal cross-section flow channels. These channels are narrower at the bottom and wider at the top, with sloping sidewalls on both sides. Water flows axially, while gas accumulates in the upper space and is then discharged. This structure can improve fluid distribution to some extent, but the sidewalls are typically smooth slopes and lack active disturbance structures. Bubbles still primarily detach from the walls due to buoyancy and mainstream shear force.
[0009] (3) Internal turbulence structure flow channel Other existing technologies incorporate raised pillars, ribs, or corrugated structures within the flow channel to enhance turbulence. These turbulence structures are typically located at the bottom or central region of the flow channel, and are characterized by continuous or periodic protrusions. They enhance mass transfer by altering the local velocity distribution. However, these structures directly encroach on the area of the main flow channel, significantly increasing pressure drop, are complex to manufacture, and are prone to creating local dead zones or liquid accumulation areas.
[0010] During the operation of a proton exchange membrane electrolyzer, the electrolysis reaction continuously generates gaseous products at the electrode / porous transport layer interface. The accumulation and retention of gas bubbles in the flow channel can easily lead to the following problems: 1. It hinders the continuous supply of liquid water to the reaction interface; Reason: In traditional PEMEC structures, liquid water on the anode side needs to pass through the flow channel, diffusion layer (PTL / GDL), and finally reach the reaction interface of the catalyst layer (CL). During electrolysis, a large number of oxygen bubbles generated preferentially nucleate and grow within the pores of the catalyst layer or PTL. As the bubbles increase in size and aggregate, they occupy part of the pore channels and surface active regions, partially blocking the transport channels for liquid water. Because traditional structures lack effective bubble desorption or guidance mechanisms, these bubbles cannot detach from the reaction interface in time, thus forming localized gas-phase occupied areas. This restricts the supply of water to the reaction interface, ultimately leading to insufficient water supply at the reaction interface and affecting the continued progress of the electrolysis reaction.
[0011] 2. Increased local flow resistance leads to increased pressure drop; Cause: During electrolysis, oxygen bubbles continuously generated enter the flow channel, forming a distinct gas-liquid two-phase flow structure. Traditional PEMEC flow channels are typically simple direct-flow or serpentine channels, lacking specialized bubble control structures. When bubbles accumulate, merge, or form bubble clusters within the flow channel, they alter the original liquid flow path, reducing the effective flow cross-sectional area, leading to increased local velocity and additional frictional losses. Simultaneously, the presence of bubbles causes flow instability and vortex structures, thereby increasing overall flow resistance, manifested as a significant increase in flow channel pressure drop.
[0012] 3. It creates a gas shielding effect in local areas, reducing the uniformity of current density; Reason: In traditional PEMECs, oxygen bubbles tend to adhere to and persist on the PTL surface or near the catalyst layer. When bubbles cover part of the active area of the catalyst layer, the electrolysis reaction interface in that area is isolated by the gas phase, forming a so-called "gas shielding effect." This phenomenon causes the electrolysis reaction to occur only in areas not covered by bubbles, resulting in a localized increase in current density, while the reaction rate in the shielded areas is significantly reduced. As bubbles continue to form and migrate, a significant non-uniformity in current density distribution emerges, thus affecting the overall electrochemical performance and stability of the electrolyzer.
[0013] 4. High current density conditions exacerbate the performance degradation of the electrolytic cell.
[0014] Reason: Under high current density operating conditions, the amount of oxygen generated per unit time increases significantly, and the bubble formation rate also increases accordingly. In traditional structures, due to limited bubble removal efficiency, a large number of bubbles tend to remain and accumulate in the pores and channels of the PTL. Bubble aggregation not only further exacerbates mass transfer resistance and gas shielding effects, but also leads to insufficient local water supply and uneven temperature and current distribution at the reaction interface. These factors increase polarization losses in the electrolytic cell, accelerate material aging and performance degradation, and significantly reduce the stable operation capability of the electrolytic cell under high current density conditions. Summary of the Invention
[0015] The purpose of this invention is to overcome the defects of the prior art by providing a proton exchange membrane electrolyzer with a sloping barbed reinforced debubbling flow channel structure, which significantly improves bubble desorption efficiency and effectively improves the uniformity of gas-liquid two-phase flow distribution; achieves the enhancement effect without significantly increasing the pressure drop; realizes layered and gradient fluid and bubble management, optimizes hydraulic performance, and controls pressure drop.
[0016] The objective of this invention can be achieved through the following technical solutions: This invention provides a proton exchange membrane electrolyzer with a sloping barbed reinforced degassing flow channel structure, comprising: a bipolar plate, a gas diffusion layer, a catalyst layer, and a proton exchange membrane; The bipolar plate is provided with at least one serpentine flow channel, and the cross-section of the serpentine flow channel is a multi-layer composite structure; The multi-layer composite structure, along a cross-section perpendicular to the axial direction of the serpentine flow channel, comprises, from bottom to top, the following: The bottom rectangular segment has a rectangular cross-section. The middle inverted trapezoidal segment has an inverted isosceles trapezoidal cross-section, and the lower base of the middle inverted trapezoidal segment is connected to the upper edge of the bottom rectangular segment; The top rectangular segment has a rectangular cross-section and is connected to the upper base of the middle inverted trapezoidal segment; In particular, on the left and right inclined walls of the central inverted trapezoidal section, multiple triangular barb structures are periodically arranged along the axial direction of the serpentine flow channel.
[0017] Furthermore, the bottom rectangular segment has a width of 1.6 mm and a height of 0.6 mm.
[0018] Furthermore, the lower base width of the inverted trapezoidal segment in the middle is 1.6mm, the upper base width is 2.0mm, and the height is 0.8mm.
[0019] Furthermore, the width of the top rectangular segment is 2.4 mm and the height is 0.4 mm.
[0020] Furthermore, the triangular barb structure is in the shape of an isosceles right triangle.
[0021] Furthermore, the base length of the isosceles right triangle is 0.2 mm, the height of the isosceles right triangle along the serpentine flow channel is 0.1 mm, and the cutting depth is 0.2 mm.
[0022] Furthermore, the tip of the triangular barb structure is arranged facing the counter-flow direction of the serpentine flow channel.
[0023] Furthermore, the spacing between adjacent triangular barb structures on the same side slope of the serpentine flow channel is 0.1 mm.
[0024] Furthermore, at each cross-section of the serpentine channel, at least three identical triangular barb structures are uniformly arranged on the left and right inclined walls, respectively.
[0025] Furthermore, the serpentine flow channel includes multiple horizontal segments and bends connecting adjacent horizontal segments, with the two ends of the serpentine flow channel being a liquid inlet and a reactant outlet, respectively.
[0026] When the electrolytic cell is running, liquid water enters through the liquid inlet and reacts in the catalytic layer on the anode side to generate oxygen bubbles. The bubbles form on the electrode surface and enter the serpentine flow channel. After passing through the gas diffusion layer, they rise along the flow channel and contact the inclined wall. The mainstream impacts the tip of the triangular barbed structure, forming a local low-pressure area at the rear edge of the triangular barbed structure. This increases the local shear stress, disrupts the bubble adhesion stability, and causes the bubbles to detach from the wall and enter the mainstream, eventually being discharged through the reactant outlet.
[0027] Compared with the prior art, the present invention has the following advantages: (1) Significantly improves bubble desorption efficiency and effectively improves the uniformity of gas-liquid two-phase flow distribution: Compared with traditional smooth-walled flow channels, the barbed structure set on the inclined wall can form a local high-shear zone and micro-scale vortex zone at the trailing edge of the barbs under the scouring of the mainstream fluid. This can effectively disrupt the stable attachment state of bubbles on the flow channel wall, induce bubbles to detach in advance, and reduce their retention on the electrodes and walls. The secondary disturbance generated by the barbed structure can promote the dispersion of rising bubbles and reduce the coalescence between bubbles, thereby reducing the probability of forming large-sized bubbles. This helps to make the gas-liquid mixing in the flow channel more uniform, reduce the risk of local bubble retention, and improve the stability of fluid distribution.
[0028] (2) Achieving enhanced performance without significantly increasing pressure drop: The overall hydraulic diameter of the flow channel in this design is on the same order of magnitude as that of a traditional 2mm x 2mm rectangular flow channel. The barbed structure is tiny (0.1mm in height and 0.2mm in depth) and is only located on the lateral inclined walls, rather than in the main flow core area at the bottom or center of the channel. This design minimizes the encroachment on the effective cross-sectional area of the main flow channel. Therefore, compared to the design of setting large-scale turbulence columns at the bottom of the channel, the added flow resistance is lower, enabling enhanced bubble desorption while maintaining a reasonable system pressure drop level.
[0029] (3) Achieve layered, gradient-style fluid and bubble management, optimize hydraulic performance, and control pressure drop. The narrow width of the bottom rectangular section helps maintain a high fluid velocity near the inlet, thereby enhancing the initial flushing ability of the reaction interface (catalytic layer), which is conducive to the rapid supply of water and the transfer of reactants. The middle inverted trapezoidal section provides a physical basis for setting up the barbed reinforcement structure. The expansion structure of the inclined wall (narrow at the bottom and wide at the top) provides a natural guiding space for the rise and migration of bubbles, guiding the desorbed bubbles to converge from both sides to the center of the channel, and creating conditions for the aggregation and upward movement of bubbles, reducing the adhesion area of bubbles on the wall. The top rectangular section serves as the collection and discharge channel for bubbles, with the widest width, forming a relatively spacious gas collection area at the top of the channel, which can effectively accommodate the bubbles desorbed from the inclined wall and rising, reducing the risk of bubbles re-blocking or merging into large gas masses near the outlet due to insufficient space, thereby ensuring the smooth discharge of the gas phase.
[0030] (4) It helps improve the overall performance and operational stability of the electrolyzer: By promoting rapid bubble desorption, the "shadowing effect" of gas on the active area of the electrode catalyst layer can be reduced, thereby improving the utilization rate of the effective reaction area, reducing concentration polarization, and improving the uniformity of current density distribution. This is especially beneficial under high current density operating conditions, which can reduce the risk of performance degradation due to mass transfer limitations, and help extend the life of the membrane electrode assembly and improve the long-term operational stability of the electrolyzer.
[0031] (5) Good processing feasibility: The barb structure is a regular isosceles right-angled triangular microstructure, which can be realized through existing mature processing methods such as CNC machining, precision milling, and mold pressing. This structure is simple, has good repeatability, and is suitable for engineering mass manufacturing, which lowers the threshold for technology implementation. Attached Figure Description
[0032] Figure 1 An exploded view of a proton exchange membrane electrolyzer with a sloping wall barbed structure to enhance the defoaming flow channel.
[0033] Figure 2 This is a three-dimensional schematic diagram of the serpentine flow channel on a bipolar plate.
[0034] Figure 3 This is a schematic diagram of the cross-section of the serpentine flow channel.
[0035] Figure 4 for Figure 2 A schematic diagram of the structure of part A.
[0036] Figure reference numerals: 1-Bipolar plate; 2-Gas diffusion layer; 3-Catalyst layer; 4-Proton exchange membrane; 11-Serpentine flow channel; 111-Liquid inlet; 112-Horizontal section; 113-Bend section; 114-Reactant outlet; 1111-Top rectangular section; 1112-Middle inverted trapezoidal section; 1113-Bottom rectangular section; 12-Triangular barbed structure. Detailed Implementation
[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.
[0038] Example 1 This embodiment provides a proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure, such as... Figure 1-4 As shown, it includes: bipolar plate 1, gas diffusion layer 2, catalyst layer 3, and proton exchange membrane 4; The bipolar plate 1 is provided with at least one serpentine flow channel 11, and the cross-section of the serpentine flow channel 11 is a multi-layer composite structure; The multi-layer composite structure, along a cross-section perpendicular to the axial direction of the serpentine flow channel 11, comprises, from bottom to top: The bottom rectangular segment 1113 has a rectangular cross-section. The middle inverted trapezoidal segment 1112 has an inverted isosceles trapezoidal cross-section, and the lower base of the middle inverted trapezoidal segment 1112 is connected to the upper edge of the bottom rectangular segment 1113. The top rectangular segment 1111 has a rectangular cross-section and is connected to the upper base of the middle inverted trapezoidal segment 1112; Among them, on the left and right inclined walls of the central inverted trapezoidal section 1112, a plurality of triangular barb structures 12 are periodically arranged along the axial direction of the serpentine flow channel 11.
[0039] Example 2 This embodiment provides a proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure, such as... Figure 1-4 As shown, it includes: bipolar plate 1, gas diffusion layer 2, catalyst layer 3, and proton exchange membrane 4; The bipolar plate 1 is provided with at least one serpentine flow channel 11, and the cross-section of the serpentine flow channel 11 is a multi-layer composite structure; The multi-layer composite structure, along a cross-section perpendicular to the axial direction of the serpentine flow channel 11, comprises, from bottom to top: The bottom rectangular segment 1113 has a rectangular cross-section. The middle inverted trapezoidal segment 1112 has an inverted isosceles trapezoidal cross-section, and the lower base of the middle inverted trapezoidal segment 1112 is connected to the upper edge of the bottom rectangular segment 1113. The top rectangular segment 1111 has a rectangular cross-section and is connected to the upper base of the middle inverted trapezoidal segment 1112; Among them, on the left and right inclined walls of the central inverted trapezoidal section 1112, a plurality of triangular barb structures 12 are periodically arranged along the axial direction of the serpentine flow channel 11.
[0040] In a specific embodiment, the bottom rectangular segment 1113 has a width of 1.6 mm and a height of 0.6 mm.
[0041] In a specific embodiment, the lower base width of the inverted trapezoidal segment 1112 in the middle is 1.6mm, the upper base width is 2.0mm, and the height is 0.8mm.
[0042] In a specific embodiment, the width of the top rectangular segment 1111 is 2.4mm and the height is 0.4mm.
[0043] In a specific embodiment, the triangular barb structure 12 is an isosceles right triangle.
[0044] In a specific embodiment, the base length of the isosceles right triangle is 0.2 mm, the height of the isosceles right triangle along the flow direction of the serpentine channel 11 is 0.1 mm, and the cutting depth is 0.2 mm.
[0045] In a specific embodiment, the tip of the triangular barb structure 12 is arranged facing the counter-flow direction of the serpentine flow channel 11.
[0046] In a specific embodiment, the spacing between adjacent triangular barb structures 12 on the same side inclined wall of the serpentine flow channel 11 is 0.1 mm.
[0047] In a specific embodiment, at least three identical triangular barb structures 12 are uniformly arranged on the left and right inclined walls at each cross-section of the serpentine flow channel 11.
[0048] In a specific embodiment, the serpentine flow channel 11 includes multiple horizontal sections 112 and a bend 113 connecting adjacent horizontal sections 112. The two ends of the serpentine flow channel 11 are a liquid inlet 111 and a reactant outlet 114, respectively.
[0049] When the electrolytic cell is running, liquid water enters through the liquid inlet 111 and reacts in the catalytic layer on the anode side to generate oxygen bubbles. The bubbles form on the electrode surface and enter the serpentine flow channel 11. After passing through the gas diffusion layer 2, they rise along the flow channel and contact the inclined wall. The mainstream impacts the tip of the triangular barbed structure 12, forming a local low-pressure area at the rear edge of the triangular barbed structure 12, which increases the local shear stress, destroys the bubble adhesion stability, and causes the bubbles to detach from the wall and enter the mainstream. Finally, they are discharged through the reactant outlet 114.
[0050] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.
[0051] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.
Claims
1. A proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure, characterized in that, include: Bipolar plate (1), gas diffusion layer (2), catalyst layer (3), proton exchange membrane (4); The bipolar plate (1) is provided with at least one serpentine flow channel (11), and the cross-section of the serpentine flow channel (11) is a multi-layer composite structure; The multi-layer composite structure, along a cross section perpendicular to the axial direction of the serpentine flow channel (11), comprises, from bottom to top: The bottom rectangular segment (1113) has a rectangular cross-section. The middle inverted trapezoidal segment (1112) has an inverted isosceles trapezoidal cross-section, and the lower base of the middle inverted trapezoidal segment (1112) is connected to the upper edge of the bottom rectangular segment (1113). The top rectangular segment (1111) has a rectangular cross-section and is connected to the upper base of the middle inverted trapezoidal segment (1112); Among them, on the left and right inclined walls of the central inverted trapezoidal section (1112), a number of triangular barb structures (12) are periodically arranged along the axial direction of the serpentine flow channel (11).
2. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The bottom rectangular segment (1113) has a width of 1.6 mm and a height of 0.6 mm.
3. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The lower base width of the inverted trapezoidal segment (1112) in the middle is 1.6mm, the upper base width is 2.0mm, and the height is 0.8mm.
4. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The top rectangular segment (1111) has a width of 2.4 mm and a height of 0.4 mm.
5. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The triangular barb structure (12) is an isosceles right triangle.
6. A proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 5, characterized in that, The base length of the isosceles right triangle is 0.2 mm, the height of the isosceles right triangle along the flow direction of the serpentine channel (11) is 0.1 mm, and the cutting depth is 0.2 mm.
7. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The tip of the triangular barb structure (12) is arranged in the opposite direction to the serpentine flow channel (11).
8. The proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The spacing between adjacent triangular barb structures (12) on the same side inclined wall of the serpentine channel (11) is 0.1 mm.
9. A proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, At each cross-section of the serpentine channel (11), at least three identical triangular barb structures (12) are uniformly arranged on the left and right inclined walls, respectively.
10. A proton exchange membrane electrolyzer with a sloping wall barbed reinforced defoaming flow channel structure according to claim 1, characterized in that, The serpentine flow channel (11) includes multiple horizontal sections (112) and a bend (113) connecting adjacent horizontal sections (112). The two ends of the serpentine flow channel (11) are a liquid inlet (111) and a reactant outlet (114), respectively.