Patent ID: 10669159

Abstract:
Provided is a complex oxide that has a high hydrogen content, contains almost no impurity phase, and is suitable for proton conductivity. The complex oxide is represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 3.2<x≤7) and is a single phase of a garnet type structure belonging to a cubic system. A method for producing the complex oxide includes an exchange step of bringing a raw material complex oxide represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 0≤x≤3.2) and a compound having a hydroxy group or a carboxyl 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 carboxyl group.