Gas diffusion layer structure of electrochemical oxygen generator membrane electrode and preparation method

Abstract

The invention discloses a gas diffusion layer structure of an electrochemical oxygenerator membrane electrode and a preparation method, the gas diffusion layer structure comprises a cathode gas diffusion layer and an anode gas diffusion layer, the cathode gas diffusion layer comprises a cathode conductive porous substrate layer and a cathode microporous layer arranged at the inner side of the cathode conductive porous substrate layer; the anode gas diffusion layer comprises an anode conductive porous substrate layer and an anode microporous layer arranged on the inner side of the anode conductive porous substrate layer, the anode microporous layer comprises carbon particles and a binder, and the cathode microporous layer comprises carbon particles, a binder, a water absorbent and an adsorption material. Compared with the prior art, the electrochemical oxygen generator has the advantages that the conductivity is good, the hydrophilic and hydrophobic properties of the cathode gas diffusion layer and the anode gas diffusion layer are different, the gas diffusion performance and the water management performance of the electrochemical oxygen generator are improved, the water-gas distribution performance of the cathode gas diffusion layer and the anode gas diffusion layer is optimized, the electrolysis rate of the anode side water is further improved, and the electrochemical oxygen generator is more stable. And oxygen can be stably produced under the condition of low humidity.

Description

technical field [0001] The invention relates to a proton exchange membrane electrochemical oxygen generator, in particular to a gas diffusion layer structure and a preparation method of a membrane electrode of an electrochemical oxygen generator. Background technique [0002] An electrochemical oxygen generator is an electrolytic cell that electrolyzes air. Its structure is similar to that of a fuel cell. One of them is a proton exchange membrane electrochemical oxygen generator, PEMEOG. PEMEOG has the advantages of rapid start-up, clean and pollution-free, high controllability, simple maintenance, low cost of continuous use, etc. It avoids the hidden danger of hydrogen and oxygen mixed explosion, and is suitable for small-scale, portable oxygen generators. [0003] The membrane electrode assembly is the core component of the proton exchange membrane electrochemical oxygen generator, which consists of a cathode gas diffusion layer, a cathode catalytic layer, a proton exchang...

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Problems solved by technology

[0004] The cathode and anode sides of the existing PEMEOG adopt the same hydrophilic and hydrophobic gas diffusion layer. Please refer to the patent publication titled "Trace Oxygen Generation Module and Its Pure Oxygen Generation System" with the application number 202011587435.2. The defects of this structure are: When the air humidity is low, there are fewer water molecules in the humid air, and the water molecules adsorbed to the cathode diffusion layer are insufficient, and the water electrolysis reaction rate of the anode decreases, resulting in low oxygen production efficiency, which cannot meet the complex working conditions of the oxygen generator. Conditions, which determine that the current commercial gas diffusion layer still needs to optimize its water management process

[0006] The disadvantages of this structure are: when the air humidity is low, there are fewer water molecules in the humid air, and the water molecules adsorbed to the cathode diffusion layer are insufficient, and the water electrolysis reaction rate of the anode is reduced, resulting in low oxygen production efficiency, which cannot Meet actual needs

In addition, in the case of low humidity, water molecules on the cathode side will diffuse into the air, the number of water molecules transferred to the anode through the proton exchange membrane will decrease, and the proton conduction resistance of the proton exchange membrane will increase, resulting in an increase in the input voltage, which is at a very high positive potential An increase in the potential received by the anode at the anode will lead to an increase in the electrochemical corrosion rate at the anode, thereby shortening the service life of the electrochemical oxygen generator and increasing energy consumption

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