Membrane electrode for fuel cell and preparation method thereof

Abstract

The invention discloses a membrane electrode for a fuel cell, and a preparation method and a packaging method thereof. A catalysis layer of the membrane electrode provided by the invention is composed of a catalyst slurry on a proton exchange membrane. The catalyst slurry comprises a catalyst, a binder, a disperse solvent, a thickening agent and an additive, and the catalyst is one selected from a Pt catalyst or a Pt alloy catalyst. The preparation method of the membrane electrode provided by the invention comprises the steps of preparation of the catalyst slurry for the membrane electrode, coating of the catalyst slurry and assembly of the membrane electrode. The preparation method of the catalyst slurry provided by the invention can shorten disperse time of the slurry and increase disperse efficiency, and the obtained catalyst slurry can realize transfer rate of 100% in a membrane electrode subassembly preparation process by a transfer printing method, so as to substantially increase utilization rate of the catalyst and electrochemical performance of the membrane electrode and effectively reduce the production cost of the fuel cell.

Description

technical field [0001] The invention relates to the field of fuel cells. Specifically, the present invention relates to a membrane electrode for a fuel cell and its preparation method, especially the composition of the catalyst slurry used in the membrane electrode, the preparation method of the membrane electrode and the sealing method of the membrane electrode. Background technique [0002] Membrane electrode assembly is the core component of proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC), which determines the electrochemical performance of the battery to a large extent. Therefore, the preparation and sealing of membrane electrodes are particularly important to improve the performance of fuel cells. [0003] As we all know, the microstructure of the catalytic layer in the membrane electrode is determined by the slurry coated on the proton exchange membrane, and the composition and degree of dispersion of the slurry have a great influence o...

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Problems solved by technology

Different membrane electrode preparation methods have different requirements on the composition of the slurry. For the transfer method that can be mass-produced industrially, the transfer rate of the slurry is a very important consideration. The reduction of porosity affects the drainage function of the cathode, which directly leads to the degradation of the performance of the battery, which needs to be improved from the composition of the catalyst slurry

Most of the currently known slurry dispersion methods are a combination of ultrasonic and magnetic stirring. These two methods are not only insufficient in dispersion, but also require a long operating time.

On the one hand, the temperature rise caused by long-term treatment makes the catalyst particles reunite. On the other hand, the large amount of solvent volatilization changes the composition of the slurry, which has a very adverse effect on the structure of the catalytic layer.

In addition, when assembling a three-in-one or five-in-one membrane electrode, the general operation is to seal it between two flow field plates with a sealing ring of a certain size, which is not conducive to the isolation of cathode and anode gases, and will also Gas leakage occurs, which greatly reduces the electrochemical performance of the fuel cell

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