Cathode catalyst layer for electrochemical devices, film electrode assembly, and electrochemical device

Abstract

This invention provides a cathode catalyst layer for electrochemical devices that is suitable for reducing costs while achieving excellent power generation performance. [Solution] The cathode catalyst layer 206 of the present disclosure has a first end 206a located upstream in the direction of cathode gas flow and a second end 206b located downstream, and includes a conductive material 11, catalyst particles 12 supported on the conductive material 11, a first ionomer 31 having an annular structure, and a second ionomer 32 not having an annular structure. The portion including the first end 206a and located on the first end 206a side is defined as the upstream portion 211, and the portion including the second end 206b and located on the second end 206b side is defined as the downstream portion 212. The proportion of the mass of the first ionomer 31 included in the upstream portion 211 is greater than the proportion of the mass of the second ionomer 32, and the proportion of the mass of the second ionomer 32 included in the downstream portion 212 is greater than the proportion of the mass of the first ionomer 31.

Claims

1. A cathode catalyst layer, The cathode catalyst layer has a first end located upstream in the flow direction of the cathode gas, which is parallel to the main surface of the cathode catalyst layer, and a second end located downstream in the flow direction. The material comprises a conductive material, catalyst particles supported on the conductive material, a first ionomer having a cyclic structure, and a second ionomer not having a cyclic structure. When the portion including the first end and located on the side of the first end is defined as the upstream portion, and the portion including the second end and located on the side of the second end is defined as the downstream portion, The ratio of the mass of the first ionomer contained in the upstream portion to the total mass of the resin components contained in the upstream portion is greater than the ratio of the mass of the second ionomer contained in the upstream portion to the total mass of the resin components contained in the upstream portion. The ratio of the mass of the second ionomer contained in the downstream portion to the total mass of the resin components contained in the downstream portion is greater than the ratio of the mass of the first ionomer contained in the downstream portion to the total mass of the resin components contained in the downstream portion. Cathode catalyst layer for electrochemical devices.

2. When the cathode catalyst layer is divided into two equal parts, part A including the first end and part B including the second end, along the direction from the first end to the second end, using the main surface of the cathode catalyst layer as the area basis, The upstream portion is included in portion A, and the downstream portion is included in portion B. A cathode catalyst layer for an electrochemical device according to claim 1.

3. When the cathode catalyst layer is divided into three equal parts, part C including the first end, part D including the second end, and part E including the second end, along the direction from the first end to the second end, with respect to the area of ​​the main surface of the cathode catalyst layer, The upstream portion corresponds to portion C, and the downstream portion corresponds to portion E. A cathode catalyst layer for an electrochemical device according to claim 1.

4. The second ionomer has a linear structure in its main chain and side chains. A cathode catalyst layer for an electrochemical device according to claim 1.

5. The conductive material is a conductive porous material having pores. A cathode catalyst layer for an electrochemical device according to claim 1.

6. The catalyst particles are arranged inside the pores of the conductive material. A cathode catalyst layer for an electrochemical device according to claim 5.

7. The catalyst particles include at least one selected from the group consisting of platinum, palladium, iridium, ruthenium, and rhodium. A cathode catalyst layer for an electrochemical device according to claim 1.

8. A-scatter, Cathode and, An electrolyte membrane disposed between the anode and the cathode, Equipped with, The cathode includes a cathode catalyst layer for an electrochemical device as described in any one of claims 1 to 7. Membrane electrode assembly.

9. A membrane electrode assembly comprising the membrane electrode assembly described in claim 8, Electrochemical devices.

10. It also includes a cathode separator, The cathode is disposed between the electrolyte membrane and the cathode separator. The cathode separator has a cathode gas channel for guiding the cathode gas to the cathode, The flow direction of the cathode gas is the flow direction of the cathode gas in the cathode gas flow path. The electrochemical device according to claim 9.

11. The cathode separator has an upstream end located on the upstream side of the cathode gas flow path and a downstream end located on the downstream side of the cathode gas flow path. When the cathode separator is divided into three equal parts, part F including the upstream end, part G including the downstream end, and part H including the downstream end, along the direction from the upstream end to the downstream end, using the main surface of the cathode separator as the area basis, The upstream portion of the cathode catalyst layer corresponds to portion F, and the downstream portion of the cathode catalyst layer corresponds to portion H. The electrochemical device according to claim 10.

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