Catalyst powder, catalyst electrode and electrochemical device

Abstract

Disclosed is a catalyst powder (1) contained in an electrode, wherein the catalyst powder includes a catalytic substance (3) supported on a conductive powder (2), the catalytic substance being comprised of at least a catalyst, the weight ratio of the catalytic substance to the catalyst powder is in the range of 55 to 75 wt%, and the areal density of the catalytic substance is in the range of 1 to 3 mg / cm 2 . Also disclosed is a catalyst electrode including the catalyst powder and a solid polymer electrolyte. Further disclosed is an electrochemical device including a plurality of electrodes, and an ionic conductor sandwiched between the electrodes, wherein the above-mentioned catalyst electrode constitutes at least one of the plurality of electrodes.

Description

Background of the invention [0001] The present invention relates to catalyst powder, catalyst electrode and electrochemical device. [0002] Solid polymer electrolyte fuel cells have higher energy density than other types of fuel cells and are considered to be easy to downsize; therefore, very high expectations are placed on the use of solid polymer electrolyte fuel cells for portable applications. expect. Thus, the solid polymer electrolyte type fuel cell constitutes a field in which much progress has been recently made in the world and much attention is being devoted to this field. [0003] The cell structure of the solid polymer electrolyte fuel cell is a multilayer structure of cathode current collector / cathode (oxygen electrode) side catalyst layer / solid polymer electrolyte / anode (fuel electrode) side catalyst layer / anode current collector, and has been Its component materials, manufacturing methods, methods of forming battery structures, etc. (see, for example, Japanes...

AI Technical Summary

Problems solved by technology

When the catalyst powder with the above-mentioned 20-55wt% catalyst particle loading ratio is used, due to the increase in the specific surface area of ​​the catalyst particles, the increase in the thickness of the catalyst layer leads to an increase in the amount of binder required, and leads to an increase in the electronic resistance of the electrode

In addition, forming a thicker catalyst layer also involves problems such as layer body cracking, which leads to a decrease in the stability of the catalyst layer

[0007] On the other hand, when a catalyst powder with a high catalyst particle load ratio is used, the specific surface area of ​​the catalyst particles is so small that a sufficient reaction area cannot be obtained, and good output characteristics cannot be obtained

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