3d printing integrated electrode structure of fish gill biomimetic design in flow battery

Abstract

The application discloses an electrode structure in a liquid flow battery, in particular to an electrode structure with fish gill biomimetic design in a liquid flow battery, wherein the electrode body forms a gill cavity structure; a flow channel one for electrolyte inflow into the gill cavity structure; and a flow channel two for electrolyte outflow from the gill cavity structure; a gill arch structure is arranged in the gill cavity structure and used for guiding electrolyte countercurrent; a gill filament structure is used for reactant diffusion mass transfer; and a gill piece structure is used for providing a large number of electrochemical reaction sites. The application solves the technical problem of integrating the structure and functional characteristics of the bipolar plate and the porous electrode in the traditional liquid flow battery by means of 3D printing integrated electrode structure design, reduces the packaging difficulty and contact resistance of the battery unit in the liquid flow battery, and improves the power density and energy efficiency of the liquid flow battery. The electrode structure is simple and efficient in manufacturing, easy to mass produce, and low in production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrode structure in a flow battery, in particular to a 3D printing integrated electrode structure of fish gill biomimetic design in a flow battery. BACKGROUND

[0002] Flow battery is one of the new energy storage technologies developed in China. Its unique advantages include independent adjustment of power and energy, high safety and long service life, which is suitable for new energy grid connection, power grid peak shaving and standby energy and other fields. Bipolar plate (responsible for electric conduction and promoting convective mass transfer) and porous electrode (providing electrochemical reaction site, while affecting mass transfer process) as core components significantly affect battery performance.

[0003] Traditionally, these two parts are made separately by subtractive manufacturing technology and then pressed together, which increases the difficulty of sealing and assembly, and because of the large contact resistance, the energy efficiency loss is serious with the increase of current density, sometimes even more than 30%. Therefore, the development of integrated design of bipolar plate and porous electrode functions is crucial to reduce packaging complexity, reduce contact resistance, improve energy efficiency and promote the development of flow battery technology.

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

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The purpose of the present application is to solve the above-mentioned problems of the prior art and provide a fish gill biomimetic design electrode structure in a flow battery, which integrates the structure and functional characteristics of the bipolar plate and the porous electrode in the traditional flow battery through integrated structure design, reduces the packaging difficulty and contact resistance of the flow battery stack unit, and improves the power density and energy efficiency of the flow battery.

[0007] In order to achieve the above-mentioned purpose, the fish gill biomimetic design 3D printing integrated electrode structure in a flow battery designed by the present application has the following structure:

[0008] The electrode body forms a gill-like cavity structure; a flow channel one for flowing electrolyte into the gill-like cavity structure; and a flow channel two for flowing electrolyte out of the gill-like cavity structure;

[0009] The gill-like arch structure is arranged in the gill-like cavity structure and used for guiding the convection of electrolyte.

[0010] The 3D printing integrated electrode structure of the fish gill biomimetic design in the flow battery has the following structure:

[0011] The gill-like arch structure preferably comprises:

[0012] The rib-shaped part one at the cavity opening and the rib-shaped part two at the cavity bottom are equidistantly and parallelly arranged in the same direction, and the rib-shaped part one and the rib-shaped part two are staggered in the direction perpendicular to the parallel arrangement direction.

[0013] Each rib-shaped part one extends from the single-side cavity wall to the opposite cavity wall of the gill-like cavity structure, and a gap is reserved between the rib-shaped part one and the symmetric cavity wall, so that the extension end surface of the rib-shaped part one and the cavity wall on the corresponding side form the path of the flow channel one.

[0014] Each rib-shaped part two also extends from the single-side cavity wall to the opposite cavity wall of the gill-like cavity structure, and the grooves formed between each two adjacent rib-shaped parts two are uniformly converged to the flow channel two.

[0015] The gill-like filament structure preferably comprises:

[0016] The V-shaped plate-shaped part is equidistantly arranged in the extension direction of the rib-shaped part one and the rib-shaped part two.

[0017] Each plate-shaped part extends from the rib-shaped part two to the corresponding rib-shaped part one in the vertical direction and then to the adjacent rib-shaped part two.

[0018] The gill-like sheet structure preferably comprises:

[0019] The sheet-shaped part extends outward from the two side surfaces of the plate-shaped part and is equidistantly arranged in the extension direction of the plate-shaped part.

[0020] Further, the 3D printing integrated electrode structure of the fish gill biomimetic design in the flow battery has the following structure:

[0021] The size of the gill-like arch structure is preferably millimeter level.

[0022] The size of the gill-like filament structure is preferably between micrometer level and millimeter level.

[0023] The size of the gill-like sheet structure is preferably micrometer level.

[0024] The application is a 3D printing integrated electrode structure of fish gill biomimetic design in flow battery, which aims to imitate the efficient gas exchange mechanism of natural fish gill to optimize the performance of flow battery. By simulating the convection of water, diffusion of oxygen and exchange process of oxygen on the capillary wall in fish gill, this electrode design can optimize the electrolyte convection, reactant diffusion and reaction process on the electrode pore surface in flow battery. Specifically, the electrode structure mainly consists of the following three parts: gill arch-like structure (millimeter level): used to guide the electrolyte convection, ensure the uniform distribution of liquid in the electrode, so that the electrolyte can realize more efficient convection in the electrode, reduce the pressure drop loss. Gill filament-like structure (between microns and millimeters): increases the diffusion path of reactants in the electrolyte to the electrode surface, promotes reactant diffusion mass transfer, improves material transport efficiency and increases reaction rate. Gill sheet-like structure (micron level): provides a large number of electrochemical reaction sites, greatly increases the effective surface area (reaction active area) of the electrode, and makes more electrochemical reactions possible.

[0025] In addition, this kind of electrode is directly prepared by using 3D printing technology, which not only reduces the packaging difficulty and contact resistance of flow battery, but also improves its power density and energy efficiency, thereby promoting the sustainable development of flow battery technology.

[0026] The application develops a 3D printing integrated electrode structure of fish gill biomimetic design in flow battery, aiming to solve the existing problems in traditional flow battery technology, such as assembly difficulty, large contact resistance, low power density and energy efficiency, etc. Based on this invention, the following specific effects can be achieved:

[0027] In terms of technology, it can improve the uniformity of electrolyte distribution. The gill arch-like structure effectively guides the electrolyte convection at the electrode inlet, ensuring its uniform distribution in the entire electrode. This improvement significantly reduces the mass transfer overpotential loss caused by uneven distribution of electrolyte. At the same time, it can increase the reaction active area and electrolyte permeability. The gill filament-like structure enhances the micro-convection of electrolyte and promotes the diffusion of reactants, increasing the contact area between electrolyte and electrode, thereby improving the reaction efficiency. The gill sheet-like structure provides a large number of micron-level electrochemical reaction sites, not only increasing the specific surface area of the electrode, but also promoting the occurrence of electrochemical reaction, significantly improving the reaction rate and efficiency. Optimizing the coupling effect of multiple physical fields, by coordinating the structure parameters of different levels (macroscopic flow channel, mesoscopic microchannel, microscopic pore), the application can balance the pressure drop loss and mass transfer overpotential loss, and maximize the energy efficiency of the battery.

[0028] Economically, it can simplify the manufacturing process. The integrated design achieved through 3D printing technology makes the manufacturing of the electrode structure simpler and more efficient, facilitating large-scale production and reducing production costs. It also reduces assembly difficulty and cost. The integrated design simplifies the battery assembly process, lowers internal resistance, reduces assembly time and material waste, and further reduces overall costs. This improves market competitiveness. Due to the simplified manufacturing process and improved performance, this electrode has good economic and market application prospects, helping to promote the commercialization of liquid flow battery technology.

[0029] Socially, this invention can promote sustainable energy development: It helps improve the performance of flow batteries, thereby promoting the development of renewable energy storage technology, which has positive implications for addressing climate change and reducing carbon emissions. Furthermore, by incorporating biomimetic design concepts, this invention provides new ideas and technical references for other fields, promoting scientific and technological progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Fig. 1 is a schematic diagram of the 3D-printed integrated electrode structure (hidden lines are visible);

[0031] Fig. 2 It is a partial cross-sectional diagram of the 3D printed integrated electrode structure;

[0032] Fig. 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.

[0033] 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

[0034] 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 embodiments described 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 are within the scope of protection of the present invention.

[0035] like Figs. 1-3 As shown, as an embodiment of the present invention, a 3D printed integrated electrode structure with a fish gill biomimetic design in a flow battery is provided in this embodiment, wherein:

[0036] The electrode body 1 forms a gill-like cavity structure 1-1; a flow channel one 1-2 for electrolyte flowing into the gill-like cavity structure 1-1; and a flow channel two 1-3 for electrolyte flowing out of the gill-like cavity structure 1-1;

[0037] A gill-like arch structure 2 is arranged in the gill-like cavity structure 1-1 for guiding the electrolyte convection; a gill-like filament structure 3 for reactant diffusion mass transfer; and a gill-like flake structure 4 for providing a large number of electrochemical reaction sites.

[0038] The gill-like arch structure 2 in the embodiment has a millimeter level size, which includes:

[0039] Rib one 2-1 at the cavity mouth and rib two 2-2 at the cavity bottom, the rib one 2-1 and the rib two 2-2 are equidistantly and parallelly distributed in the same direction, and the rib one 2-1 and the rib two 2-2 are staggered in the direction perpendicular to the parallel distribution direction thereof;

[0040] Wherein, each rib one 2-1 extends from the single side cavity wall to the opposite cavity wall of the gill-like cavity structure 1-1, and the extending end surface of the rib one 2-1 and the cavity wall on the corresponding side thereof form the path of the flow channel one 1-2 through the gap 2-3 reserved between the symmetric cavity walls;

[0041] Wherein, each rib two 2-2 also extends from the single side cavity wall to the opposite cavity wall of the gill-like cavity structure 1-1, and the grooves 2-4 formed between each adjacent two rib two 2-2 are uniformly converged to the flow channel two 1-3;

[0042] The gill-like filament structure 3 has a size between microns and millimeters, which includes:

[0043] A V-shaped plate-shaped part 3-1 equidistantly distributed in the extending direction of the rib one 2-1 and the rib two 2-2;

[0044] Wherein, each plate-shaped part 3-1 extends from the rib two 2-2 to the corresponding rib one 2-1 in the vertical direction thereof and then to the adjacent rib two 2-2 thereof;

[0045] The gill-like flake structure 4 has a micron level size, which includes:

[0046] A flaky part 4-1 extending outward from the two side plates of the plate-shaped part 3-1 and equidistantly distributed in the extending direction of the plate-shaped part 3-1.

[0047] The specific flow path of the electrolyte in the above-mentioned 3D printed integrated electrode structure of the fish gill biomimetic design in the liquid flow battery is as follows: Fig. 1As shown, after the electrolyte flows into the electrode inlet, it first passes through multiple gill arch-like structures 2, which are mainly used to guide the convection of the electrolyte; 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 and mass transfer; finally, gill-like platelet structures 4 are further evenly distributed on the gill filament-like structures 3, providing a large number of electrochemical reaction positions.

[0048] This embodiment also provides a method for preparing the above-mentioned 3D printed integrated electrode structure, which uses light-curing 3D printing and pyrolysis slow carbonization technology. The method mainly includes the following specific steps:

[0049] Step 1: Use AUTOCAD to draw the optimized 3D printed integrated electrode structure.

[0050] 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.

[0051] Step 3: Print using stereolithography 3D printing technology. In this example, acrylate was used as the precursor, and a Formlabs Form3 printer was used. This device boasts a laser spot size of 85 μm, an XY axis accuracy of 25 μm, a print layer thickness of 25 μm–300 μm, and a print size of 145 mm x 145 mm x 185 mm, meeting the requirements for printing the biomimetic electrodes with cross-scale structures described in this invention.

[0052] 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 preliminary 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. The splint not only plays a shaping role but also allows the release of pyrolysis gas.

[0053] Step 5: Evaluate the degree of electrode deformation after carbonization and further modify the above process to obtain the ideal 3D printed integrated electrode structure.

[0054] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, any technical solution that is the same or similar to that of the present application falls within the scope of protection of the present invention.

Claims

1. A 3D printed integrated electrode structure with a fish gill biomimetic design for a flow battery, characterized by: The electrode body forms a gill-like structure; a first flow channel for electrolyte to flow into the gill-like structure; and a second flow channel 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 provided for reactant diffusion and mass transfer; and, gill-like platelets, which are used to provide a large number of electrochemical reaction sites; The branchial arch-like structure comprises: The rib portion 1 located at the cavity opening and the rib portion 2 located at the cavity bottom are equidistantly and parallelly distributed in the same direction, and the rib portion 1 and the rib portion 2 are staggered with respect to each other in a direction perpendicular to their parallel distribution direction; Each rib-shaped portion extends from a single cavity wall of the branchial cavity structure to the opposite cavity wall, and a gap is left between the symmetrical cavity wall, thereby forming a flow channel path between the extended end surface of the rib-shaped portion 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 the opposite side cavity wall, and the grooves formed between each two adjacent rib-shaped portions 2 converge into the flow channel 2; The gill filament-like structure comprises: V-shaped plate portions, which are evenly spaced in the extending direction of the first and second rib 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 comprises: The sheet-like parts extend outwards from both side surfaces of the plate-like part and are evenly distributed in the extending direction of the plate-like part.

2. The 3D printed integrated electrode structure with fish gill biomimetic design in a flow battery according to claim 1, characterized in that: The size of the branchial arch-like structure is in the millimeter order; The size of the gill-like filament structure is between micrometer level and millimeter level; Furthermore, the size of the gill-like platelet structure is on the micron level.

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