Membrane electrode for proton exchange membrane fuel cell and producing method thereof

Abstract

A film electrode used on proton exchange film fuel cell consists of five layers as middle layer of total F proton exchange film, two external layers of catalytic layers and two layers of diffusion layers outside of two external layers. Its preparing method includes embedding nanofibre proton conductor network in catalytic layer, preparing a layer of nanofibre proton conductor multiple film on total F proton exchange film surface by static spinning technique, coating ink containing catalyst in proton conductor fibre, drying and heat rolling to obtain film electrode containing nanofibre proton conductor network in catalytic layer.

Description

technical field [0001] The invention relates to a membrane electrode used in a proton exchange membrane fuel cell and a preparation method thereof, and specifically provides a membrane electrode with good catalytic layer / proton exchange membrane interface adhesion and conductivity and a preparation method thereof. Background technique [0002] Proton Exchange Membrane Fuel Cell (PEMFC) is an electrochemical energy conversion device that directly converts chemical energy in fuel and oxidant into electrical energy. The PEMFC system consists of the following parts. The electrolyte is a proton exchange membrane (PEM); the catalyst is carbon-supported Pt or carbon-supported Pt-Ru alloy; the fuel is pure hydrogen or reformed hydrogen-rich gas or methanol; the oxidant is air or pure oxygen; Bipolar plates are graphite or surface-modified metal plates with gas and water flow channels. Since the chemical energy is directly converted into electrical energy without being limited by th...

AI Technical Summary

Problems solved by technology

There are two obvious deficiencies in the membrane electrode of the thick hydrophobic catalytic layer: the mass content of the proton conductor in the catalyst layer is about 20%, the proton conductivity is low, and the conductance is about 1 / 10 of the proton exchange membrane. When the density is working, the reaction is mainly concentrated in the interface area close to the proton exchange membrane, resulting in a decrease in the utilization rate of Pt; the other is that the concentration gradient of Nafion in the interface area of ​​the catalytic layer / proton exchange membrane is large, and the mass content in the catalytic layer is about 20%. 100% into the proton exchange membrane, which is not conducive to the good adhesion between the Nafion membrane and the catalytic layer, resulting in partial peeling of the electrode and the proton exchange membrane when the battery is running for a long time, increasing the interface resistance

The proton conductor resin such as Nafion or Flemion in the catalytic layer mainly exists in the form of particles. Although it has undergone a hot pressing process, it cannot effectively improve the interface bonding performance. The granular proton conductor resin is also not conducive to the formation of a good proton conductor network, thus affecting the battery. The high current characteristics, the stability of the interface during long-term operation, and the vibration resistance required in electric vehicles

Images