Anode for alkaline water electrolysis and method for producing same

Patent metadata

Field	Value
Publication number	US-11965256-B2
Application number	US-202118248848-A
Country	US
Kind code	B2
Filing date	Oct 14, 2021
Priority date	Oct 15, 2020
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

The present invention provides an alkaline water electrolysis anode such that even when electric power having a large output fluctuation, such as renewable energy, is used as a power source, the electrolysis performance is unlikely to be deteriorated and excellent catalytic activity is retained stably over a long period of time. The alkaline water electrolysis anode is an alkaline water electrolysis anode 10 provided with an electrically conductive substrate 2 at least a surface of which contains nickel or a nickel base alloy and a catalyst layer 6 disposed on the surface of the electrically conductive substrate 2 , the catalyst layer 6 containing a nickel-containing metal oxide having a spinel structure, wherein the nickel-containing metal oxide contains nickel (Ni) and manganese (Mn), and has an atom ratio of Li/Ni/Mn/O of (0.0 to 0.8)/(0.4 to 0.6)/(1.0 to 1.8)/4.0.

First claim

The invention claimed is:

1. An alkaline water electrolysis anode comprising:
an electrically conductive substrate at least a surface of which comprises nickel or a nickel base alloy;
an intermediate layer on the electrically conductive substrate; and
a catalyst layer disposed on a surface of the intermediate layer, the catalyst layer comprising a nickel-containing metal oxide having a spinel structure,
wherein the intermediate layer disposed between the electrically conductive substrate and the catalyst layer comprises a lithium-containing nickel oxide represented by compositional formula LixNi 2-x O 2 wherein x is in a range of 0.02≤x≤0.5, and
the nickel-containing metal oxide comprises nickel (Ni) and manganese (Mn), and has an atom ratio of Li/Ni/Mn/O in a range of (0.0 to 0.8)/(0.4 to 0.6)/(1.0 to 1.8)/4.0.

2. The alkaline water electrolysis anode according to claim 1 , wherein a proportion of manganese (Mn) having a valence of four in all the manganese (Mn) in the nickel-containing metal oxide is in a range of 99 mol % or more.

3. A method for producing an alkaline water electrolysis anode, comprising:
subjecting an electrically conductive substrate having a surface coated with an aqueous solution comprising a lithium ion and a nickel ion to a first thermal treatment so as to form an intermediate layer on the surface of the electrically conductive substrate, the intermediate layer comprising a lithium-containing nickel oxide represented by compositional formula LixNi 2-x O 2 wherein x is in a range of 0.02≤x≤0.5, and at least the surface of the electrically conductive substrate comprising nickel or a nickel base alloy;
subjecting a precursor comprising a lithium component, a nickel component, and a manganese component to a second thermal treatment so as to form a layer comprising a lithium composite oxide on a surface of the intermediate layer; and
reacting nitronium tetrafluoroborate (NO 2 BF 4 ) with the lithium composite oxide, thereby chemically performing delithiation, so as to form, on the surface of the intermediate layer, a catalyst layer comprising a nickel-containing metal oxide having a controlled lithium content and having a spinel structure, wherein
the nickel-containing metal oxide comprises nickel (Ni) and manganese (Mn), and has an atom ratio of Li/Ni/Mn/O in a range of (0.0 to 0.8)/(0.4 to 0.6)/(1.0 to 1.8)/4.0.

4. The method for producing an alkaline water electrolysis anode according to claim 3 , wherein the precursor is subjected to the second thermal treatment at a temperature in a range from 400° C. to 900° C. in an oxygen-containing atmosphere.

5. The method for producing an alkaline water electrolysis anode according to claim 3 , wherein the precursor is subjected to the second thermal treatment in an oxygen-containing atmosphere having an oxygen partial pressure in a range of 0.2 atm or higher.

Assignees

• Univ Kyoto
• Nat Univ Corp Yokohama Nat Univ
• De Nora Permelec Ltd

Inventors

• Uchimoto Yoshiharu
• Uchiyama Tomoki
• Mitsushima Shigenori
• Kuroda Yoshiyuki
• Nagasawa Kensaku
• Nishiki Yoshinori
• Zaenal Awaludin
• Bao Yun

Classifications

• C25B11/052 Primary

  Electrodes comprising one or more electrocatalytic coatings on a substrate · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C25B11/061

  Metal or alloy · CPC title

• C25B11/0771

  of the spinel type · CPC title

• C25B15/021

  of heating or cooling · CPC title