Centrosymmetric radial bipolar plate flow field structure for solid polymer electrolyte (SPE) electrolysis

Abstract

The invention discloses a centrosymmetric radial bipolar plate flow field structure for solid polymer electrolyte (SPE) electrolysis. The centrosymmetric radial bipolar plate flow field structure for SPE electrolysis comprises a bipolar plate body, an internal radial flow channel, an external radial flow channel, a pressure equalizing transition belt, an outlet notch and a communication region, wherein the bipolar plate body is provided with a water inlet and an outlet; the internal radial flow channel is composed of a plurality of internal ring ridges which extend in the radial direction of the bipolar plate body and are centrally symmetrical, and the external radial flow channel is composed of a plurality of external ring ridges; the pressure equalizing transition belt is arranged between the internal radial flow channel and the external radial flow channel; the outlet notch communicates with the tail end of the external radial flow channel; the communication region communicates with the outlet notch and the outlet; and the water inlet is located in the center of the bipolar plate body and communicates with the internal radial flow channel. According to the centrosymmetric radial bipolar plate flow field structure for SPE electrolysis, the centrally-symmetrical radial ridges form the flow channels, so that the distances of the flow channels are shortened; and the pressure in all flow channel units is evenly distributed through the pressure equalizing transition belt, and the distribution uniformity of the pressure and water in a flow field is kept under the condition that the number of water inlets is not increased, so that the hydrogen yield of an SPE electrolytic tank manufactured based on the centrosymmetric radial bipolar plate flow field structure can be increased by increasing the catalyst loading areas or/and the overlapping number of membrane electrode assemblies (MEAs), the electrolytic efficiency is improved, and the service life is prolonged.

Description

technical field [0001] The invention relates to the technical field of SPE electrolysis, in particular to a centrosymmetric radial bipolar plate flow field structure for SPE electrolysis. Background technique [0002] The solid polymer electrolyte (Solid Polymer Electrolyte, SPE) electrolysis uses pure water as the raw material, and the core component is a zero-gap sandwich membrane electrode assembly separated by bipolar plates. Compared with the traditional alkaline water electrolysis, it has a compact structure, High electrolysis efficiency, high gas purity, long service life and other significant advantages. [0003] As the core component of the bipolar plate of the SPE electrolytic cell, the flow field directly affects the electrolysis efficiency and service life of the stack. During electrolysis, water passes through the inlet of the anode bipolar plate and distributes the anode side of the proton exchange membrane through the flow field, OH - Oxygen is produced in c...

AI Technical Summary

Problems solved by technology

In order to fully reduce the eddy current caused by the introduction of raw water from multiple inlets, the anode bipolar plate usually has only one raw water inlet, which requires extremely high flow field design, and an unreasonable design of the flow field will not only generate high mass transfer resistance , cause gas and heat retention, and also cause uneven distribution of water pressure in the flow field, so that the catalyst in some areas on the proton exchange membrane cannot fully contact and react with water, which will reduce the service life of the stack and cause low electrolysis efficiency. It is not conducive to the development of large flow SPE single stack

[0004] Common flow fields include parallel, serpentine, and interdigitated flow fields. The above flow fields have a simple structure and are easy to process. The mass transfer resistance of stacked membrane electrode assemblies (Membrane Electrode Assemblies, MEA) increases significantly with the increase of the catalyst area or (and) the number of stacks

In order to improve the above defects and balance the contradiction between design and processing, some patents have partially optimized the common flow field. For example, the patent CN 103806014A uses an improved parallel flow field. The elbow design used can improve the heat dissipation of the flow field, but there is a long flow path. , the mass transfer defect that the gas cannot be discharged in time

The flow field designed using the principles of bionics (such as leaf veins, human lung vascular network) can also improve the above defects to a certain extent, but it has the disadvantages of difficult processing and high manufacturing cost, and it is difficult to be practically applied in the short term.

Due to the defects of the flow field design, in order to increase the flow rate of hydrogen, most of the existing commercial SPE electrolytic cells adopt a series or mixed layout of multiple small stacks (small-area membrane electrode assemblies with a low number of stacks), which makes the system complex and relatively reliable. Low, high later maintenance costs

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