Proton-conductive complex oxide and fuel cell using same as electrolyte

Patent metadata

Field	Value
Publication number	US-10807878-B2
Application number	US-201615753904-A
Country	US
Kind code	B2
Filing date	Aug 19, 2016
Priority date	Aug 21, 2015
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

Provided is a complex oxide that has a space group I-43d, has a high hydrogen content, contains almost no impurity phase, exhibits almost no aluminum substitution in the structure thereof, and is suitable for proton conductivity. This complex oxide is represented by a chemical formula Li7-x-yHxLa3Zr2-yMyO12 (M represents Ta and/or Nb, 3.2<x≤7−y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system, and the crystal structure thereof is a space group I-43d.

First claim

What is claimed is:

1. A method for producing a complex oxide, comprising:
an exchange step of bringing a raw material complex oxide represented by a chemical formula Li 7-x-y H x La 3 Zr 2-y M y O 2 (M represents Ta and/or Nb, 0≤x≤3.2, and 0.25<y<2) and a compound having a hydroxy group or a carboxy group into contact with each other to exchange at least some of lithium of the raw material complex oxide and hydrogen of the compound having a hydroxy group or a carboxy group,
wherein the complex oxide is represented by a chemical formula Li 7-x-y H x La 3 Zr 2-y M y O 12 (M represents Ta and/or Nb, 3.2<x≤7−y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system,
wherein a crystal structure thereof is a space group I-43d.

2. The method for producing the complex oxide according to claim 1 ,
wherein the compound having a hydroxy group or a carboxy group is included in an acidic aqueous solution or is pure water or alcohol.

3. The method for producing the complex oxide according to claim 1 ,
wherein in the exchange step, the raw material complex oxide and the compound having a hydroxy group or a carboxy group are brought into contact with each other at a temperature of 80° C. to 200° C.

4. The method for producing the complex oxide according to claim 1 ,
wherein in the exchange step, the raw material complex oxide and the compound having a hydroxy group or a carboxy group are brought into contact with each other for 12 hours or longer.

Assignees

• Aist

Inventors

• Akimoto Junji
• HAMAO Naoki
• Kataoka Kunimitsu

Classifications

• C01G33/006 Primary

  Compounds containing niobium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• H01M4/88

  Processes of manufacture · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M8/1246

  the electrolyte consisting of oxides · CPC title

• C01G25/006

  Compounds containing zirconium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title