Electrode and method of producing the same, and electrochemical device using the same

Patent metadata

Field	Value
Publication number	US-2023411629-A1
Application number	US-202118252191-A
Country	US
Kind code	A1
Filing date	Nov 9, 2021
Priority date	Nov 12, 2020
Publication date	Dec 21, 2023
Grant date	—

Abstract

An electrode used for oxygen reactions, the electrode being excellent in catalytic activity and stability, a method of producing the electrode, and an electrochemical device using the electrode are provided. This electrode includes, as an oxygen catalyst, an oxide that has peaks at positions of 2θ=34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuKα ray and has constituent elements of bismuth, ruthenium, sodium, and oxygen.

First claim

1 . An electrode used for oxygen reactions, the electrode comprising, as an oxygen catalyst, an oxide that has peaks at positions of 2θ=34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuKα ray and has constituent elements of bismuth, ruthenium, sodium, and oxygen.

2 . The electrode according to claim 1 , wherein an atomic ratio of the oxygen to the bismuth and an atomic ratio O/Ru of the oxygen to the ruthenium are both more than 3.5.

3 . The electrode according to claim 1 , wherein the oxygen reactions occur in an alkaline aqueous solution as an electrolyte.

4 . The electrode according to claim 1 , wherein the oxygen catalyst has a primary particle size of 100 nm or less.

5 . The electrode according to claim 1 , wherein the oxygen catalyst has a secondary particle size of 3 μm or less.

6 . The electrode according to claim 1 , comprising a gas diffusion layer.

7 . The electrode according to claim 1 , comprising a catalytic layer that includes the oxygen catalyst, a conducting material, and a water-repellent material as constitutional materials.

8 . The electrode according to claim 7 , wherein graphite having different particle sizes is used as the conducting material.

9 . The electrode according to claim 7 , being formed into a thin plate shape and having a thickness of 250 μm or less.

10 . The electrode according to claim 7 , comprising a water-repellent layer, through which oxygen can permeate, on an atmosphere side of the catalytic layer or a gas diffusion layer.

11 . The electrode according to claim 10 , wherein the water-repellent layer is made of water-repellent material particles.

12 . The electrode according to claim 1 , being the air electrode of an air battery, the oxygen cathode of brine electrolysis, the cathode of an alkaline fuel cell, or the anode of alkaline water electrolysis.

13 . The electrode according to claim 1 , comprising a non-electronically conductive reaction space divider arranged on an electrolyte side, the reaction space divider including a plurality of electrolyte holder portions consisting of a concave space configured to hold a liquid electrolyte.

14 . A method of producing an electrode used for oxygen reactions, the method comprising a step 1 of synthesizing an oxygen catalyst being an oxide that has peaks at positions of 2θ=30.07°±1.00°, 34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuKα ray and has constituent elements of bismuth, ruthenium, sodium, and oxygen; and a step 2 of producing a catalytic layer that includes the oxygen catalyst, a conducting material, and a water-repellent material.

15 . The method of producing an electrode according to claim 14 , wherein an atomic ratio O/Bi of the oxygen to the bismuth and an atomic ratio O/Ru of the oxygen to the ruthenium are both more than 3.5.

16 . The method of producing an electrode according to claim 14 , wherein the oxygen catalyst has a secondary particle size of 3 μm or less, in the step 1.

17 . The method of producing an electrode according claim 14 , wherein graphite having different particle sizes is used as the conducting material, in the step 2.

18 . The method of producing an electrode according claim 14 , comprising a step 3 of forming a gas diffusion layer on the catalytic layer or integrating the catalytic layer with a gas diffusion layer.

19 . The method of producing an electrode according claim 14 , comprising a step 4 of including a current collector integrated with the catalytic layer or a gas diffusion layer, applying a suspension containing a water-repellent material on a surface opposite to a side in contact with an electrolyte, and subsequently applying heat treatment.

20 . An electrochemical device using the electrode according to claim 1 .

21 . The electrochemical device according to claim 20 , being an air battery, a brine electrolyzer, an alkaline water electrolyzer, an alkaline fuel cell, or a water electrolysis and fuel cell device that uses an alkaline aqueous solution as an electrolyte.

22 . The electrochemical device according to claim 21 , wherein the air battery has a negative electrode active material, which is hydrogen, lithium, sodium, potassium, magnesium, calcium, or zinc.

Assignees

• The Doshisha

Inventors

• Morimitsu Masatsugu

Classifications

• H01M4/8647 Primary

  consisting of more than one material, e.g. consisting of composites · CPC title

• H01M4/9008

  Organic or organo-metallic compounds · CPC title

• H01M4/8807

  Gas diffusion layers · CPC title

• H01M4/8821

  Wet proofing · CPC title

• H01M2300/0014

  Alkaline electrolytes · CPC title