Integral welding structure of flattened electrode and current collector and preparation process of integral welding structure

Abstract

The invention relates to the technical field of alkaline water electrolysis hydrogen production devices, and particularly discloses an integral welding structure of a flattened electrode and a current collector and a preparation process of the integral welding structure of the flattened electrode and the current collector, and the integral welding structure of the flattened electrode and the current collector comprises a current collector substrate, a mastoid array, the flattened electrode and a welding layer. According to the invention, the interface resistance is obviously reduced, the energy efficiency is improved, and the hydrogen production cost is directly reduced; the structural stability and the operation reliability are enhanced, and the service life of equipment is prolonged; the current distribution is optimized, and the reaction efficiency and consistency are improved; the process compatibility is good, and large-scale production is easy to realize; unification of the structure and the function is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alkaline water electrolysis hydrogen production devices, and particularly relates to an electrode and current collector connecting structure for an alkaline electrolytic cell and a process, more particularly to a whole welding structure of a flattened electrode and a current collector and a preparation process thereof. BACKGROUND

[0002] The alkaline electrolytic cell is a key equipment for large-scale hydrogen production, and its core components are composed of electrodes, diaphragms and current collectors. Among them, the interface contact between the current collector (usually a flow guide plate with a papillary structure) and the electrode is one of the key links to determine the ohmic loss and energy efficiency of the electrolytic cell.

[0003] In the traditional structure, the electrode (usually a porous structure such as a woven nickel mesh or a nickel foam) and the papilla of the current collector are mechanically attached and current is conducted through limited point contact. However, this contact mode has many problems, which are specifically manifested as follows: Mismatch of geometric shape: the three-dimensional woven electrode mesh has a structure of undulating peaks and valleys, and the top of the papilla (hemispherical or cylindrical protrusions) on the surface of the current collector is also a curved surface. Although the papillary structure can improve the uniformity of the flow field, when the two are in contact, only a few peaks of the papilla top and the electrode mesh wire will form micro point or short line contact in theory, that is, the contact between the three-dimensional mesh structure of the woven electrode and the papilla is limited, which will result in that the actual effective conductive contact area is much smaller than the theoretical apparent area; Bottleneck effect of current path: all the current collected from the electrode to the current collector (or vice versa) must "squeeze through" these sparse and narrow contact points; this bottleneck effect causes the current lines to be highly concentrated near the contact points, resulting in significant current congestion and forming a high contact resistance, which requires a higher operating voltage for the electrolytic cell to maintain the target current density, and the power consumption is significantly increased; Unreliability of mechanical contact: under the assembly pressure of the electrolytic cell and the thermal cycle of long-term operation, this loose point contact may be loose or micro-movement, further exacerbating the instability of the contact resistance.

[0004] In summary, the electrode and the papilla in the prior art are in an insufficient and unstable "point contact", and this inherent interface contact mode is a fundamental structural defect that causes the overall resistance of the system to increase and the energy consumption to rise. SUMMARY

[0005] Therefore, in order to solve the problem of high resistance and high energy consumption between the electrode and the current collector caused by point contact in the prior art, the application provides a whole welding structure of a flattened electrode and a current collector and a preparation process thereof, which aims to significantly reduce the interface contact resistance between the electrode and the current collector in the alkaline electrolytic cell.

[0006] To achieve the above object, the present application adopts the following technical solutions: A whole welding structure of a flattened electrode and a current collector, comprising: A current collector substrate, which is a conductive metal plate, serving as the main support and main current path of the whole structure; A papillary array, which is a plurality of conductive protrusions uniformly distributed on one or both surfaces of the current collector substrate; A flattened electrode, which is made of a metal woven mesh with a three-dimensional structure by pressing; the wire of the metal woven mesh after pressing is flattened, so that the metal woven mesh forms a relatively flat lower surface macroscopically, and the three-dimensional pore channels formed by the interlacing of the wire are partially compressed but still capable of allowing electrolyte and gas to pass through; the flattened electrode covers the papillary array; A welding layer, which is located between the contact interface of the flattened electrode and the papillary array, and is a layer of metallurgical bonding formed by a welding process; the flattened electrode is continuously and seamlessly metallurgically bonded to the top surface and part of the side surface of each conductive protrusion in the papillary array through the welding layer.

[0007] Preferably, the current collector substrate is a nickel plate or a steel plate plated with nickel on the surface; the metal woven mesh is a nickel woven mesh or a nickel alloy woven mesh.

[0008] Preferably, the conductive protrusions are in a semispherical or cylindrical shape; the conductive protrusions are integrally formed with the current collector substrate, or the conductive protrusions are directly welded on the current collector substrate.

[0009] A preparation process of a whole welding structure of a flattened electrode and a current collector, comprising the following steps: S1, electrode pretreatment and flattening: selecting a metal woven mesh with a three-dimensional structure as the electrode raw material, and cold plastic deforming the metal woven mesh to make a flattened electrode; S2, surface cleaning: cleaning the surface of the flattened electrode and the papillary array on the current collector substrate to remove oil stains and oxide layers; S3, positioning and assembly: accurately covering the cleaned flattened electrode on the papillary array of the current collector substrate; S4, whole welding: welding the flattened electrode and the papillary array of the current collector substrate, and firmly bonding the top surface and part of the side surface of each conductive protrusion in the papillary array through the welding layer.

[0010] Preferably, the flattening process in step S1 is: cold plastic deforming the metal woven mesh with a three-dimensional structure through a pair of precision distance-adjustable rollers or placing it in a flat press.

[0011] Preferably, the pressing force in the flattening process of step S1 needs to be controlled within a range sufficient to cause plastic deformation of the metal mesh wires but not breakage.

[0012] Preferably, the reduction in the flattening process of step S1 needs to be controlled to a state where the metal mesh is compressed to achieve a balance between optimal flatness and internal three-dimensional pore retention.

[0013] Preferably, in step S2, the cleaning method includes organic solvent cleaning, pickling or plasma treatment.

[0014] Preferably, in step S3, after covering the flattened electrode on the papilla array, a slight pre-tightening force needs to be applied to the flattened electrode by a tooling fixture.

[0015] Preferably, the welding method in step S4 is one or both of laser welding and resistance roll welding, wherein laser welding is scanning welding or spot welding along the profile of each conductive protrusion using a laser beam, and resistance roll welding is using a roll welding wheel to roll on the surface of the flattened electrode to form a series of welding spots with each conductive protrusion below under the action of pressure and current.

[0016] Compared with the prior art, the overall welded structure of the flattened electrode and the current collector and the preparation process thereof of the present application, through the synergistic innovation of structure remodeling and interface fusion, brings the following significant beneficial effects: 1. Significantly reduces interface resistance, improves energy efficiency, and directly reduces hydrogen production cost Effect: The present application fundamentally changes the contact mode of the electrode from "point contact" to "surface contact" by flattening the electrode, and finally forms "volume connection" through welding, which significantly increases the effective conductive area, thereby reducing the interface contact resistance to a very low level.

[0017] Positive impact: Under the same current density, the operating voltage of the electrolytic cell can be significantly reduced, the electrical energy loss is greatly reduced, the energy consumption cost of hydrogen production is directly reduced, and the economic benefit is significant.

[0018] 2. Enhances structural stability and operational reliability, prolongs equipment life Effect: The metallurgical bonding interface formed by overall welding has much higher mechanical strength than mechanical pressing. It can effectively resist stress relaxation and fretting wear caused by the start-stop and thermal cycling of the equipment, ensuring the long-term stability of the interface resistance.

[0019] Positive impact: Avoids the problem of increased resistance and local overheating caused by loose contact points, improves the performance consistency of the electrolytic cell in long-term operation, reduces the maintenance requirements, and prolongs the service life of the core components.

[0020] 3. Optimized current distribution, improved reaction efficiency and consistency Effect: Extremely low interfacial resistance and stable connection ensure uniform distribution of current to the entire electrode surface, eliminating "current congestion" and local overload caused by uneven contact points.

[0021] Positive impact: The current density and reaction activity distribution on the electrode surface are more uniform, which not only helps to improve the overall reaction efficiency, but also avoids local rapid decay or failure, which is beneficial to improve the purity and stability of gas output.

[0022] 4. Good process compatibility, easy to realize large-scale production Effect: The flattening and welding process in the invention belongs to mature industrial technology, which is easy to integrate into existing production lines. This scheme does not need to make complex changes to the macrostructure of the current collector papilla, and the implementation difficulty and incremental cost are controllable.

[0023] Positive impact: It provides a simple, reliable and easy-to-scale technical path for the manufacture of high-performance, low-energy alkaline electrolytic cells, and effectively promotes the development and industrial application of low-cost, high-efficiency hydrogen production technology.

[0024] 5. Realize the unity of "structure" and "function" Effect: The structure of the invention realizes excellent conductivity while retaining the micro-pore and papilla structure of the flattened electrode, which perfectly inherits the advantages of traditional structure in gas-liquid transmission, realizing the perfect unity of "high conductivity" and "smooth flow".

[0025] Positive impact: It ensures that the ohmic loss is reduced while not introducing new mass transfer resistance, realizing the overall improvement of the comprehensive performance of the electrolytic cell. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without creative labor.

[0027] Figure 1 It is a whole schematic diagram of the unflattened electrode.

[0028] Figure 2 It is a schematic diagram of the unflattened electrode in contact with the lower structure.

[0029] Figure 3 It is a schematic diagram of the flattened electrode in the invention in contact with the lower structure.

[0030] Figure 4 Schematic diagram of point contact between the unflattened electrode and each conductive protrusion on the current collector substrate.

[0031] Figure 5 Corresponding flattened electrode cross-sectional diagram taken by light microscope after pressing under 10t pressure.

[0032] Figure 6 Corresponding flattened electrode cross-sectional diagram taken by light microscope after pressing under 20t pressure.

[0033] Figure 7 Corresponding flattened electrode cross-sectional diagram taken by light microscope after pressing under 35t pressure.

[0034] Figure 8 Hydrogen evolution performance comparison diagram of conventional unflattened electrode and flattened electrode pressed under 35t pressure.

[0035] In the figure: 1 - current collector substrate, 2 - papillary array, 3 - metal woven mesh with three-dimensional structure. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below with reference to examples shown in the attached drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0037] Example 1: The present embodiment provides a whole welding structure of flattened electrode and current collector, which comprises a current collector substrate 1, a papillary array 2, a flattened electrode and a welding layer.

[0038] Among them, the current collector substrate 1 is a conductive metal plate, which serves as the main support and main current path of the entire structure.

[0039] In a further specific embodiment, the current collector substrate is preferably a nickel plate or a steel plate with a nickel-plated surface.

[0040] The nipple array 2 consists of several conductive protrusions uniformly distributed on one or both sides of the current collector substrate.

[0041] In a further specific embodiment, the conductive protrusion is hemispherical (see [reference]). Figure 4 The conductive protrusions can be cylindrical or other shapes; they can be integrally formed with the current collector substrate or directly soldered to the current collector substrate. The functions of the conductive protrusions include supporting electrodes, forming flow channels, and serving as primary structural connection points after soldering.

[0042] The flattened electrode is made of a metal braided mesh with a three-dimensional structure 3 (see reference). Figure 1 , Figure 2 The metal woven mesh is formed by plastic pressing, preferably using nickel woven mesh or nickel alloy woven mesh; after pressing, the mesh wires are flattened, giving the metal woven mesh a relatively flat lower surface macroscopically, while the three-dimensional pore channels formed by the interlacing wires are partially compressed but still allow the electrolyte and gas to pass through (see...). Figure 3 ).

[0043] This embodiment flattens and shapes a traditional three-dimensional electrode mesh, creating a novel flattened electrode structure that combines large-area planar contact characteristics with the retention of micropore conductivity. The flattened electrode covers the papillary array, and its flattened lower surface is in large-area contact with the surface of the conductive protrusions, and is subsequently welded into a conductive rigid whole.

[0044] The welding layer is located between the contact interface between the flattened electrode and the papillary array, and is a metallurgical bonding layer formed by the welding process. The flattened electrode achieves a continuous, seamless and firm metallurgical bond with the top surface and part of the side surface of each conductive protrusion in the papillary array through the welding layer. In other words, the welding layer realizes the transformation of the flattened electrode and the papillary array from mechanical contact to metallurgical bonding.

[0045] This embodiment replaces simple mechanical contact with welding, forming a low-resistance, highly stable metallurgical bonding interface between the electrode and each conductive protrusion, thus completely eliminating contact resistance.

[0046] In this embodiment, "flattening" provides an ideal, scalable, flattened interface for "welding," while "welding" ultimately locks in and enhances the contact area advantage brought by "flattening." Both are indispensable and together constitute the core technical means by which this invention reduces energy consumption and improves performance. In other words, the core of this embodiment lies in the synergy of structural reshaping and interface fusion, which fundamentally improves the interface's conductivity.

[0047] The working principle of this embodiment is as follows: after the current is collected from the flattened electrode (as the reaction site), it is efficiently conducted to the protrusion array through the welded layer with a large contact area, and then enters the current collector substrate (or is conducted in the reverse direction). Because the interface is metallurgically bonded, the contact resistance is reduced to an extremely low level, almost equivalent to the resistance of the bulk material. At the same time, because the three-dimensional porous channels formed by the interlaced wires are only partially compressed, the gaps between the conductive protrusions are preserved, thereby ensuring the smooth flow of electrolyte and reactive gas.

[0048] In general, the integral welding structure of the flattened electrode and the current collector in this embodiment achieves the following specific objectives: 1) Achieved efficient surface contact conductivity: By flattening the three-dimensional woven mesh electrode, the contact mode between it and the current collector papilla is changed from the inherent "point contact" to a large-area "surface contact", which fundamentally expands the effective conductive area and reduces current conduction loss. 2) Improved energy conversion efficiency: By significantly reducing the contact resistance between the electrode and the current collector, the working voltage and overall energy consumption of the electrolyzer are directly reduced, achieving higher hydrogen production efficiency; 3) Enhanced structural stability and reliability: Through integral welding technology, the flattened electrode and the current collector are combined into a robust integrated structure, eliminating resistance instability caused by loose contact and improving the durability of the equipment under long-term operation and thermal cycling.

[0049] Example 2: This embodiment provides a fabrication process for an integral welding structure of a flattened electrode and a current collector, including the following steps: S1. Electrode pretreatment and flattening: Select a metal woven mesh with a three-dimensional structure (such as nickel woven mesh or nickel alloy woven mesh) as the electrode raw material, and perform cold pressing plastic deformation on the metal woven mesh to produce a flattened electrode. S2. Surface cleaning: Clean the surface of the flattened electrode and the papillary array on the current collector substrate to remove oil and oxide layer to ensure the quality of subsequent welding. S3. Positioning and Assembly: Precisely cover the cleaned flattened electrodes onto the papillary array of the current collector substrate; S4. Overall welding: The flattened electrode is welded to the nipple array of the current collector substrate. The top surface and part of the side surface of each conductive protrusion in the nipple array are firmly bonded together by the welding layer, so that the flattened electrode and the current collector substrate become a conductive rigid whole.

[0050] More specifically, the flattening process in step S1 is as follows: the metal woven mesh with a three-dimensional structure is cold-pressed and plastically deformed by passing it through a pair of precisely adjustable rollers or by placing it in a flatbed press.

[0051] In the above flattening process, the pressing force needs to be controlled within a range sufficient to cause plastic deformation of the metal woven mesh without breaking it, for example, 10t~35t. The amount of compression of the metal woven mesh needs to be controlled so that the metal woven mesh is compressed to achieve a balance between optimal flatness and retention of internal three-dimensional pores.

[0052] More specifically, in step S2, the cleaning methods include organic solvent cleaning, acid washing (such as dilute hydrochloric acid or dilute nitric acid), or plasma treatment.

[0053] More specifically, in step S3, after the flattened electrode is covered on the papillary array, a slight pre-tightening force needs to be applied to the flattened electrode using a tooling fixture to ensure that the flattened electrode fits tightly with the papillary array.

[0054] More specifically, in step S4, one or both of laser welding or resistance roll welding methods are used to achieve the overall connection. Laser welding involves using a laser beam to scan and weld or skip spot weld along the contour of each conductive protrusion. Resistance roll welding involves using a welding roller to roll on the surface of the flattened electrode, forming a series of weld points with each conductive protrusion below under pressure and current.

[0055] In summary, the fabrication process of the integral welding structure of the flattened electrode and the current collector in this embodiment has the following innovations: 1) This process flattens the braided electrode mesh structure through physical pressing, transforming its three-dimensional pores into a planar extended structure, which significantly increases the contact area between the electrode and the mastoid surface. 2) This process integrates the flattened electrode and the nipple current collector into an integrated structure by welding. During the welding process, the flat surface of the flattened electrode and the raised surface of the nipple form a large-area contact, and the metallurgical bonding interface is formed by welding, which eliminates the contact gap and reduces the interface resistance. 3) This process is simple and does not require complex modifications to the existing current collector nipple structure. It can achieve low-resistance and high-stability interface connection, making it easy to scale up production and application.

[0056] The following is a further verification of the effects that this invention can achieve: Figure 1The image shown is a schematic diagram of the unflattened electrode. Figure 2 The diagram shows the contact between the unflattened electrode and the lower structure. Figure 3 The diagram shows the flattened electrode in contact with the lower structure in this invention.

[0057] contrast Figure 2 , Figure 3 It is evident that after the electrode is flattened, its contact area with the underlying structure is significantly increased.

[0058] Figure 4 The diagram shows point contact between the unflattened electrode and the conductive protrusions on the current collector substrate. Figure 5 The image shown is a cross-section of the flattened electrode, captured by a pressure optical microscope, after cold-pressing plastic deformation of the original unflattened electrode under a pressure of 10t. Figure 6 The image shows a cross-section of the flattened electrode, captured by a pressure optical microscope, after cold-pressing plastic deformation of the original unflattened electrode under a pressure of 20t. Figure 7 The image shows the cross-section of the flattened electrode after cold-pressing plastic deformation under a pressure of 35t, as captured by a pressure optical microscope.

[0059] Tests conducted using an optical microscope on the interface of electrode sheets subjected to different pressures revealed that under a pressure of 35t, the cross-section of the flattened electrode tends to become planar.

[0060] Furthermore, Figure 8 To be Figure 1 The conventional unflattened electrode shown in the figure and Figure 7 The graph shown is a comparison of the hydrogen evolution performance of different electrodes after the flattened electrodes pressed under 35t pressure were tested for performance in an installed machine.

[0061] Table 1 below compares the operating voltages of flattened electrodes and conventional non-flattened electrodes.

[0062] Table 1

[0063] Table 2 below compares the hydrogen production energy consumption of flattened electrodes with that of conventional non-flattened electrodes.

[0064] Table 2

[0065] The test results above show that, compared with the traditional structure where the electrodes are not flattened and are only connected by mechanical contact, the component prepared by the method of flattening the electrodes and then welding according to the present invention reduces the operating voltage from 2.27V to 1.91V at a current density of 3000A / m², a reduction of 0.36V; and the hydrogen production energy consumption reduces from 5.43kW·h to 4.56kW·h, saving approximately 16.0% of energy. This effect verifies the effectiveness of the method of the present invention. By performing a two-step process of flattening and then welding, the technical problem of high resistance and high energy consumption caused by the small contact area between the electrode and the current collector is successfully solved.

[0066] Therefore, based on the above verification results, the following conclusions can be drawn: Flattened electrode structures can significantly reduce the operating voltage of electrolyzers. This directly demonstrates that by increasing the contact area and reducing contact resistance, the ohmic polarization overpotential is effectively reduced, improving the electrochemical efficiency of the system and thus directly lowering the energy cost of hydrogen production, resulting in extremely significant economic benefits. Especially in scenarios where industrial electrolyzers operate continuously year-round, this energy-saving effect will bring millions of yuan in operating cost savings.

[0067] This invention also demonstrates the innovative structural improvement that fundamentally enhances the contact interface between the electrode and the current collector, achieving low voltage, low energy consumption, and high performance. It can well adapt to and meet the industry's technical needs for high current density, large scale, and intensive development, providing key technical support for the development of the next generation of high-performance electrolytic cells.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0069] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An integral welded structure for a flattened electrode and a current collector, characterized in that, include: The current collector substrate is a conductive metal plate that serves as the main support and main current path for the entire structure. A papillary array is a plurality of conductive protrusions uniformly distributed on one or both surfaces of the current collector substrate. The flattened electrode is formed by pressing a metal woven mesh with a three-dimensional structure. After pressing, the wires of the metal woven mesh are flattened, so that the metal woven mesh forms a relatively flat lower surface macroscopically. At the same time, the three-dimensional pore channels formed by the interlacing wires are partially compressed but can still allow the electrolyte and gas to pass through. The flattened electrode covers the papillary array. The welding layer, located between the contact interface of the flattened electrode and the papillary array, is a metallurgical bonding layer formed by welding process; the flattened electrode achieves continuous and seamless metallurgical bonding with the top surface and part of the side surface of each conductive protrusion in the papillary array through the welding layer.

2. The integral welding structure of the flattened electrode and the current collector according to claim 1, characterized in that, The current collector substrate is a nickel plate or a steel plate plated with nickel; the metal woven mesh is a nickel woven mesh or a nickel alloy woven mesh.

3. The integral welding structure of the flattened electrode and the current collector according to claim 1, characterized in that, The conductive protrusion is hemispherical or cylindrical; the conductive protrusion is integrally formed with the current collector substrate, or the conductive protrusion is directly welded to the current collector substrate.

4. A fabrication process for an integral welded structure of a flattened electrode and a current collector, as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Electrode pretreatment and flattening: Metal woven mesh with a three-dimensional structure is selected as the electrode raw material. The metal woven mesh is cold-pressed and plastically deformed to produce flattened electrodes. S2. Surface cleaning: Clean the surface of the flattened electrode and the papillary array on the current collector substrate to remove oil and oxide layer; S3. Positioning and Assembly: Precisely cover the cleaned flattened electrodes onto the papillary array of the current collector substrate; S4. Overall welding: The flattened electrode is welded to the protrusion array of the current collector substrate. The top surface and part of the side surface of each conductive protrusion in the protrusion array are firmly bonded together by the welding layer.

5. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 4, characterized in that, The flattening process in step S1 is as follows: the metal woven mesh with a three-dimensional structure is cold-pressed and plastically deformed by passing it through a pair of precisely adjustable rollers or by placing it in a flatbed press.

6. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 5, characterized in that, In step S1, the flattening process, the pressing force must be controlled within a range sufficient to cause plastic deformation of the wires of the metal woven mesh without breaking it.

7. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 5, characterized in that, In the flattening process of step S1, the amount of compression of the metal woven mesh needs to be controlled so that the metal woven mesh is compressed to achieve a balance between optimal flatness and retention of internal three-dimensional pores.

8. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 4, characterized in that, In step S2, the cleaning method includes organic solvent cleaning, acid washing, or plasma treatment.

9. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 4, characterized in that, In step S3, after the flattened electrode is covered on the papillary array, a slight pre-tightening force needs to be applied to the flattened electrode using a tooling fixture.

10. The fabrication process of the integral welding structure of the flattened electrode and the current collector according to claim 4, characterized in that, The welding method in step S4 is one or both of laser welding and resistance roll welding. Laser welding is to use a laser beam to scan and weld or skip spot weld along the contour of each conductive protrusion. Resistance roll welding is to use a rolling welding wheel to roll on the surface of the flattened electrode, and under the action of pressure and current, form a series of weld points with each conductive protrusion below.

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