Fuel cell membrane electrode using polymer superbhort fiber as hydrophobic agent and its preparing method

Abstract

A fuel cell membrane electrode using polymer ultra-short fiber as water repellent and it's the preparation method, in which the catalyst layer is dopped with polymer ultra-short fiber. The preparation method is that: coat the catalyst pulp containing load-type catalyst, solid polymer electrolyte, polymer ultra short fiber and the solvent on to gas diffusion layer surface to get a gas diffusion layer electrode, hot press this electrode and the proton exchange membrane to prepare the membrane electrode; Or transfer solidified catalyst onto two sides of the proton exchange membrane to prepare the catalyst / membrane central assembly. Advantages : raised water discharge function comparing with grain-like polymer water repellent, having good reaction gas dispersion path, raised structure and catalyst size stability and simple preparation process of membrane electrode.

Description

technical field [0001] The invention relates to a membrane electrode for a proton exchange membrane fuel cell and a preparation method thereof, in particular to a membrane electrode for a proton exchange membrane fuel cell containing ultra-short polymer fibers in a catalyst layer and a preparation method thereof, and to prepare a catalyst layer for the membrane electrode It has good gas channels, and the mechanical strength and dimensional stability are enhanced. Background technique [0002] Proton exchange membrane fuel cell is a power generation device that directly converts chemical energy into electrical energy by electrochemical means, and is considered to be the preferred clean and efficient power generation technology in the 21st century. This is because the fuel cell is not limited by the Carnot cycle and has high energy conversion efficiency. And since it is H 2 and O 2 The chemical reaction, the product of which is water, realizes zero discharge in the true sen...

AI Technical Summary

Problems solved by technology

Na treatment of Nafion can increase its treatment temperature, but it will make the nano-Pt in the Pt / C catalyst grow up, and the proton exchange membrane needs to be protonized after MEA preparation, which makes the membrane electrode synthesis process complicated

2) PTFE often wraps Pt / C electrocatalyst particles in the form of spherical particles during the blending and precipitation process with catalyst particles. Since PTFE is a non-conductor, the conductor performance of the catalyst particles decreases and the membrane electrode resistance increases.

If the catalyst layer is stretched, in addition to the fibrillation of PTFE, it will also cause fibrillation of the solid polymer electrolyte, which reduces the three-phase reaction interface of the catalyst layer.

In addition, in the process of preparing diffusion layer electrodes, 200-300°C hot-pressing treatment will obviously coke the solid polymer electrolyte and reduce the life of the membrane electrode.

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