Method for carbonizing gaseous diffusion layer of modified proton exchanging film fuel battery

Abstract

A method for carbonizing the gas diffusion layer of the proton exchanging membrane fuel cell is provided, which relates to a preparation method for gas diffusion layer of the proton exchanging membrane fuel cell. The invention overcomes the shortcomings of the block for gas mass transfer caused by high PTFE capacity and the electrical conductivity decreasing of carbon paper electron. The approach of the invention is as follows: first, immersing the carbon paper in 10 to 50 wt. % aqueous solution of carbohydrate or hydrocarbon polymer for 30 to 80 min, drying the carbon paper up for 20 to 24 hours under the condition of 50 to 80 degrees centigrade, sintering the paper for 30 to 60 minutes in tubular furnace with the temperature of 350 to 400 degrees centigrade and under the protection of Ar gas; second, repeat the first operation step; third, immersing the carbonized carbon paper in 5 to 20wt. percent emulsion of Polytetrafluoethylene for 10 to 30 minutes. Thus the gas diffusion layer of carbon paper carbonized modification proton exchanging membrane fuel cell is obtained. The Polytetrafluoethylene capacity of the product in the invention is 10 to 20wt. percent . The invention has the advantage of improving the electrical conductivity of cell gas diffusion layer and porosity factor.

Description

technical field [0001] The invention relates to a method for preparing a gas diffusion layer of a proton exchange membrane fuel cell, belonging to the field of proton exchange membrane fuel cells, in particular to a method for preparing a gas diffusion layer of a proton exchange membrane fuel cell modified by carbonization of carbon paper. Background technique [0002] Proton exchange membrane fuel cells have many advantages such as high power density, fast start-up, and environmental friendliness. The requirements for miniaturization include normal temperature start-up, maintenance-free work, portability, portable and easy-to-replace hydrogen source, and self-breathing oxygen electrodes. . [0003] The gas diffusion layer (Gas Diffusion Layer, GDL) plays a role in the proton exchange membrane fuel cell to support the catalytic layer, collect current, conduct gas to the catalytic layer, discharge the reaction product water, and transport electrons between the catalytic layer...

AI Technical Summary

Problems solved by technology

[0005] 1. Increased electron transport resistance of the gas diffusion layer

[0006] 2. Excessive PTFE loading reduces the effective porosity of the gas diffusion layer, which seriously affects the mass transfer of the cathode reaction gas

[0007] To sum up, simply relying on increasing the PTFE load to improve the reverse diffusion ability of water must reduce the performance of the battery to a certain extent.

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