Gaseous diffusion layer of proton exchange membrane fuel cell and preparation method thereof

Abstract

The invention discloses a gaseous diffusion layer of a proton exchange membrane fuel cell and a preparation method thereof. The diffusion layer comprises a basal layer and a micropore layer, and the micropore layer consists of a micropore lining layer and a micropore surface layer. The micropore lining layer is located between the basal layer and the micropore surface layer, the micropore lining layer is the micropore layer with larger porosity and stronger hydrophobicity, and the micropore surface layer the micropore layer with smaller porosity and weaker hydrophobicity in comparison with the micropore lining layer. The preparation method comprises the steps of: water-repellency treatment, slurry preparation, micropore layer coating and roasting at high temperature. Because gas diffuses from the basal layer to the micropore layers in the fuel cell reaction, by manufacturing the micropore layers in the gaseous diffusion layer step by step in the invention, gradient decrease is formed between the porosities from the basal layer to the two micropore layers in the gaseous diffusion layer, which is more beneficial to the diffusion of reaction gas and the discharge of water generated by the cell, and the power of the cell can be obviously improved.

Description

technical field [0001] The invention relates to a preparation technology of a proton exchange membrane fuel cell, in particular to a gas diffusion layer of a proton exchange membrane fuel cell and a preparation method thereof. Background technique [0002] A proton exchange membrane fuel cell is a power generation system that generates direct current through the electrochemical reaction of hydrogen and oxygen. The specific reaction process is: [0003] 2H 2 →4H + +4e - (1) [0004] o 2 +4e - →2O 2- +4H + →2H 2 O (2) [0005] Equation (1) represents the oxidation reaction taking place at the anode. During this process hydrogen molecules are converted into protons and electrons, and the protons are conducted to the cathode. Equation (2) represents the reduction reaction that takes place at the cathode. In this process, oxygen atoms accept electrons to become oxygen ions, which react with hydrogen protons from the anode to form water molecules. [00...

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Problems solved by technology

However, the commonly used gas diffusion layer has a large gap in porosity between the microporous layer and the base layer, which is especially unfavorable for the discharge of generated water.

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