3D printing integrated electrode structure of fish gill bionic design in flow battery

Abstract

The invention discloses an electrode structure in a flow battery, and particularly relates to an electrode structure with bionic fish gill design in the flow battery, and an electrode main body forms a gill cavity-like structure; the flow channel I is used for allowing electrolyte to flow into the gill-cavity-like structure; the flow channel II is used for the electrolyte in the gill-cavity-like structure to flow out; a gill arch-like structure is arranged in the gill cavity-like structure and is used for guiding electrolyte convection; the gill filament-like structure is used for diffusion and mass transfer of reactants; and the gill-like small sheet structure is used for providing a large number of electrochemical reaction sites. The technical problems that the 3D printing integrated electrode structure design integrates the structure and functional characteristics of a bipolar plate and a porous electrode in a traditional flow battery, the packaging difficulty and the contact resistance of an electric pile unit in the flow battery are reduced, and the power density and the energy efficiency of the flow battery are improved are solved. The electrode structure is simpler and more efficient to manufacture, large-scale production is facilitated, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to an electrode structure in a liquid flow battery, in particular to a 3D printed integrated electrode structure with a fish gill bionic design in a liquid flow battery. Background Art

[0002] Liquid flow battery is one of the new energy storage technologies that my country focuses on developing. Its unique advantages include independent regulation of power and energy, high safety and long life, and it is suitable for new energy grid connection, grid peak regulation and backup energy. As core components, bipolar plates (responsible for conducting electricity and promoting convection mass transfer) and porous electrodes (providing a place for electrochemical reactions and affecting the mass transfer process) significantly affect battery performance.

[0003] Traditionally, these two parts are made separately through subtractive manufacturing technology and then pressed together, which increases the difficulty of sealing and assembly. In addition, due to the large contact resistance, the energy efficiency is seriously lost as the current density increases, sometimes even exceeding 30%. Therefore, the development of an integrated design that integrates the functions of bipolar plates and porous electrodes is crucial to reducing packaging complexity, reducing contact resistance, improving energy efficiency, and promoting the development of flow battery technology.

[0004] The 3D printing process is simple and can achieve the refinement and cross-scale processing of complex device structures. It is suitable for manufacturing bipolar plates and porous electrodes with specific microstructures. For example, metal laser sintering combined with conductive coating can be used to use materials such as stainless steel as precursors to prepare bipolar plates with three-dimensional lung-like fractal flow channel structures. This structure helps to further optimize the distribution of reactants and reduce pressure drop losses, thereby improving the energy efficiency of the battery.

[0005] Therefore, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art and to provide an electrode structure with a fish gill bionic design in a liquid flow battery, which integrates the structural and functional characteristics of the bipolar plates and porous electrodes in traditional liquid flow batteries through an integrated structural design, reduces the packaging difficulty and contact resistance of the battery stack unit in the liquid flow battery, and improves the power density and energy efficiency of the liquid flow battery.

[0007] In order to achieve the above-mentioned object, the present invention provides a 3D printed integrated electrode structure of fish gill bionic design in a flow battery, wherein: The electrode body forms a gill-like structure; a flow channel 1 for electrolyte to flow into the gill-like structure; and a flow channel 2 for electrolyte in the gill-like structure to flow out; A gill-like arch structure is provided in the gill-like cavity structure for guiding electrolyte convection; a gill-like filament structure is used for reactant diffusion and mass transfer; and a gill-like platelet structure is used for providing a large number of electrochemical reaction sites.

[0008] The above-mentioned 3D printed integrated electrode structure of fish gill bionic design in the liquid flow battery has the following structure: The branchial arch-like structure preferably comprises: The rib-shaped portion 1 located at the cavity opening and the rib-shaped portion 2 located at the cavity bottom, the rib-shaped portion 1 and the rib-shaped portion 2 are equidistantly distributed in parallel in the same direction, and the rib-shaped portion 1 and the rib-shaped portion 2 are mutually offset in a direction perpendicular to the parallel distribution direction thereof; Each rib-shaped portion 1 extends from a single-side cavity wall of the branchial cavity structure to an opposite-side cavity wall, and a gap is reserved between the symmetrical cavity wall, so that a flow channel 1 is formed between the extended end surface of the rib-shaped portion 1 and the cavity wall on the corresponding side; Each rib-shaped portion 2 also extends from a single-side cavity wall of the branchial cavity structure to an opposite-side cavity wall, and the grooves formed between each two adjacent rib-shaped portions 2 converge uniformly into the flow channel 2; The gill filament-like structure is preferably selected to include: V-shaped plate-shaped portions, which are evenly spaced in the extending direction of the first and second rib-shaped portions; Each plate-shaped portion first extends from the rib-shaped portion 2 to the rib-shaped portion 1 corresponding to it in the vertical direction and then extends to the adjacent rib-shaped portion 2; The gill-like platelet structure is preferably selected to include: The sheet-like parts extend outwards from the two side surfaces of the plate-like part and are evenly distributed in the extending direction of the plate-like part.

[0009] Furthermore, in the above-mentioned flow battery, the 3D printed integrated electrode structure with fish gill bionic design has the following structure: The size of the branchial arch-like structure is preferably selected to be in the millimeter level; The size of the gill-like filament structure is preferably between micrometer level and millimeter level; Furthermore, the size of the gill-like platelet structures is preferably in the micrometer range.

[0010] The present invention discloses a 3D printed integrated electrode structure of fish gill bionic design in a flow battery. The electrode is designed to optimize the performance of the flow battery by imitating the efficient gas exchange mechanism of natural fish gills. By simulating the convection of water in the fish gills, the diffusion of oxygen, and the exchange process of oxygen on the capillary wall, this electrode design can optimize the electrolyte convection, reactant diffusion, and the reaction process on the electrode pore surface in the flow battery. Specifically, the electrode structure is mainly composed of the following three parts: gill arch structure (millimeter level): used to guide the convection of the electrolyte, ensure the uniform distribution of the liquid in the electrode, so that the electrolyte can achieve more effective convection in the electrode, reducing the pressure drop loss. Gill filament structure (between micrometer level and millimeter level): increases the diffusion path of the reactants in the electrolyte to the electrode surface, promotes the diffusion and mass transfer of the reactants, improves the material transfer efficiency, and increases the reaction rate. Gill platelet structure (micrometer level): provides a large number of electrochemical reaction sites, greatly increases the effective surface area (reaction active area) of the electrode, and provides the possibility for more electrochemical reactions.

[0011] In addition, the use of 3D printing technology to directly prepare such electrodes not only reduces the packaging difficulty and contact resistance of flow batteries, but also improves their power density and energy efficiency, thereby promoting the sustainable development of flow battery technology.

[0012] The present invention aims to solve the existing problems in traditional flow battery technology, such as difficult assembly, high contact resistance, low power density and energy efficiency, by developing a 3D printed integrated electrode structure with fish gill bionic design in flow battery. Based on this invention, the following specific effects can be achieved: Technically, it is possible to improve the uniformity of electrolyte distribution. The gill arch-like structure effectively guides electrolyte convection at the electrode entrance to ensure its uniform distribution throughout the electrode. This improvement significantly reduces the mass transfer overpotential loss caused by uneven electrolyte distribution. At the same time, it can increase the reactive area and electrolyte permeability. The gill filament-like structure increases the contact area between the electrolyte and the electrode by enhancing the microscopic convection of the electrolyte and promoting the diffusion of reactants, thereby improving the reaction efficiency. Improve the electrochemical reaction rate and efficiency. The large number of micron-level electrochemical reaction sites provided by the gill-like platelet structure not only increases the specific surface area of ​​the electrode, but also promotes the occurrence of electrochemical reactions, significantly improving the reaction rate and efficiency. By optimizing the multi-physical field coupling effect and coordinating the structural parameters at different levels (macroscopic flow channels, mesoscopic microchannels, and microscopic pores), the present invention can balance the pressure drop loss and mass transfer overpotential loss to maximize the battery energy efficiency.

[0013] Economically, it can simplify the manufacturing process. The integrated design achieved by 3D printing technology makes the manufacturing of the electrode structure simpler and more efficient, easy to mass produce, and reduces production costs. It can also reduce the difficulty and cost of assembly. The integrated design simplifies the assembly process of the battery, reduces the internal resistance of the battery, reduces assembly time and material waste, and further reduces the overall cost. Improve market competitiveness. Due to the simplified manufacturing process and improved performance, the electrode has good economy and market application prospects, which will help promote the commercialization of liquid flow battery technology.

[0014] In society, it can promote the development of sustainable energy: the present invention helps to improve the performance of liquid flow batteries, thereby promoting the development of renewable energy storage technology, which has a positive significance for addressing climate change and reducing carbon emissions. At the same time, by introducing the concept of bionic design, the present invention provides new ideas and technical references for other fields, promoting the progress of science and technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the 3D printed integrated electrode structure (hidden lines are visible); Figure 2 It is a partial cross-sectional schematic diagram of the 3D printed integrated electrode structure; Figure 3 It is a schematic diagram of the combined structure of the gill arch-like structure, the gill filament-like structure and the gill lamella-like structure.

[0016] In the figure: electrode body 1, gill cavity-like structure 1-1, flow channel 1 1-2, flow channel 2 1-3, gill arch-like structure 2, rib 1 2-1, rib 2 2-2, gap 2-3, groove 2-4, gill filament-like structure 3, plate-like part 3-1, gill plate-like structure 4, plate-like part 4-1. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0018] like Figures 1 to 3 As shown, as an embodiment of the present invention, a 3D printed integrated electrode structure with fish gill bionic design in a flow battery provided in this embodiment has a structure in which: The electrode body 1 forms a gill-like structure 1-1; a flow channel 1-2 for electrolyte to flow into the gill-like structure 1-1; and a flow channel 2-3 for electrolyte in the gill-like structure 1-1 to flow out; A gill arch-like structure 2 is provided in the gill cavity-like structure 1-1 for guiding electrolyte convection; a gill filament-like structure 3 for reactant diffusion and mass transfer; and a gill platelet-like structure 4 for providing a large number of electrochemical reaction sites.

[0019] The size of the branchial arch-like structure 2 in this embodiment is in the millimeter level, and includes: The rib-shaped portion 1 2-1 located at the cavity opening and the rib-shaped portion 2-2 located at the cavity bottom, the rib-shaped portion 1 2-1 and the rib-shaped portion 2-2 are equidistantly distributed in parallel in the same direction, and the rib-shaped portion 1 2-1 and the rib-shaped portion 2-2 are mutually offset in a direction perpendicular to the parallel distribution direction thereof; Each rib-shaped portion 2-1 extends from a single-side cavity wall of the branchial cavity structure 1-1 to the opposite cavity wall, and a gap 2-3 is reserved between the symmetrical cavity wall, thereby forming a flow channel 1-2 between the extended end surface of the rib-shaped portion 2-1 and the cavity wall on the corresponding side; Each rib-shaped portion 2-2 also extends from a single-side cavity wall of the branchial cavity structure 1-1 to the opposite-side cavity wall, and the grooves 2-4 formed between each two adjacent rib-shaped portions 2-2 converge into the flow channel 1-3; The gill-like filament structure 3 has a size between micrometer and millimeter, and includes: V-shaped plate-like portions 3-1 are evenly spaced in the extending direction of the rib-like portions 1-2-1 and 2-2; Each plate-shaped portion 3-1 first extends from the rib-shaped portion 2-2 to the corresponding rib-shaped portion 1-2-1 in the vertical direction and then extends to the adjacent rib-shaped portion 2-2; The size of the gill-like platelet structure 4 is micrometer-level, and it includes: The sheet-like portions 4 - 1 extend outwardly from both side surfaces of the plate-like portion 3 - 1 and are equidistantly distributed in the extending direction of the plate-like portion 3 - 1 .

[0020] The specific flow path of the electrolyte in the 3D printed integrated electrode structure of the fish gill bionic design in the above-mentioned flow battery is as follows: Figure 1 As shown, after the electrolyte flows into the electrode inlet, it first passes through a plurality of gill arch-like structures 2, which are mainly used to guide the electrolyte convection; then, the gill arch-like structures 2 extend a large number of directionally distributed gill filament-like structures 3, which can promote microscopic electrolyte convection and reactant diffusion mass transfer; finally, the gill filament-like structures 3 are further evenly distributed with gill-like platelets 4, providing a large number of electrochemical reaction positions.

[0021] This embodiment also provides a method for preparing the above-mentioned 3D printed integrated electrode structure, which is processed by light-curing 3D printing and pyrolysis slow carbonization technology. The method mainly includes the following specific steps: Step 1: Use AUTOCAD to draw the optimized 3D printed integrated electrode structure.

[0022] Step 2: Load the CAD file obtained in step 1 into the 3D printing software PreForm, and convert the designed electrode structure into a printable structure.

[0023] Step 3: Print using photocuring 3D printing technology. In this embodiment, acrylate is used as a precursor, and a Form3 printer produced by Formlabs is used. The laser spot of the device is 85 um, the XY axis accuracy is 25 um, the printing layer thickness is 25 um-300 um, and the printing size is 145 mm x 145 mm x 185 mm, which can meet the printing requirements of the bionic electrode with a cross-scale structure in the present invention.

[0024] Step 4: Heat treat the printed electrode to make it conductive. First, place the electrode in a muffle furnace for slow low-temperature pyrolysis treatment. The muffle furnace is an air atmosphere with a heating rate of 1 °C / min, a maximum temperature of 250 °C, and a treatment time of 5 h. This step achieves the initial carbonization of the electrode while minimizing deformation. Next, use a tubular furnace to perform rapid high-temperature heat treatment on the electrode. The tubular furnace is a nitrogen atmosphere with a heating rate of 5 °C / min, a maximum temperature of 850 °C, and a treatment time of 1 h. This step achieves complete carbonization of the electrode. In addition, to avoid severe deformation of the electrode, the electrode is placed in a meshed stainless steel splint during the heat treatment process, which not only plays a shaping role but also allows the release of pyrolysis gas.

[0025] Step 5: Evaluate the degree of deformation of the electrode after carbonization and further modify the above process to obtain an ideal 3D printed integrated electrode structure.

[0026] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A 3D printed integrated electrode structure with fish gill bionic design in a flow battery, characterized by: The electrode body forms a gill-like structure; a flow channel 1 for electrolyte to flow into the gill-like structure; and a flow channel 2 for electrolyte in the gill-like structure to flow out; A gill-like arch structure is provided in the gill-like cavity structure for guiding electrolyte convection; a gill-like filament structure is used for reactant diffusion and mass transfer; and a gill-like platelet structure is used for providing a large number of electrochemical reaction sites.

2. The 3D printed integrated electrode structure of fish gill bionic design in a flow battery according to claim 1, characterized in that: The branchial arch-like structure comprises: The rib-shaped portion 1 located at the cavity opening and the rib-shaped portion 2 located at the cavity bottom, the rib-shaped portion 1 and the rib-shaped portion 2 are equidistantly distributed in parallel in the same direction, and the rib-shaped portion 1 and the rib-shaped portion 2 are mutually offset in a direction perpendicular to the parallel distribution direction thereof; Each rib-shaped portion 1 extends from a single-side cavity wall of the branchial cavity structure to an opposite-side cavity wall, and a gap is reserved between the symmetrical cavity wall, so that a flow channel 1 is formed between the extended end surface of the rib-shaped portion 1 and the cavity wall on the corresponding side; Each rib-shaped portion 2 also extends from a single-side cavity wall of the branchial cavity structure to an opposite-side cavity wall, and the grooves formed between each two adjacent rib-shaped portions 2 converge uniformly into the flow channel 2; The gill filament-like structure comprises: V-shaped plate-shaped portions, which are evenly spaced in the extending direction of the first and second rib-shaped portions; Each plate-shaped portion first extends from the rib-shaped portion 2 to the rib-shaped portion 1 corresponding to it in the vertical direction and then extends to the adjacent rib-shaped portion 2; The gill-like lamella structure comprises: The sheet-like parts extend outwards from the two side surfaces of the plate-like part and are evenly distributed in the extending direction of the plate-like part.

3. The 3D printed integrated electrode structure of fish gill bionic design in a flow battery according to claim 2, characterized in that: The size of the branchial arch-like structure is in the millimeter range; The size of the gill filament-like structure is between micrometer level and millimeter level; Furthermore, the size of the gill-like platelet structure is in the micron level.

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