Hexagonal Perovskite Solid Electrolyte for Lower-Temperature SOFCs

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Solution Overview

Problem

Conventional solid oxide fuel cells (SOFCs) using YSZ as a solid electrolyte require high operating temperatures, necessitating specific environmental conditions and equipment for operation, limiting their applicability and efficiency.

Innovation Solution

A solid electrolyte comprising hexagonal perovskite-related compounds with specific chemical formulas, exhibiting high electrical conductivity at lower temperatures (300 to 1200°C), allowing for reduced operational restrictions and expanded application range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If YSZ is used as a solid electrolyte, then sufficient oxide ion conductivity is achieved, but high operating temperature (700°C or more) is required

Engineering Contradiction:
Improveoxide ion conductivityVSAvoidoperating temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent changes the chemical composition parameters of the solid electrolyte by using hexagonal perovskite-related compounds with specific formulas (Ba3(B,B')2O9-y and Ba4M2B2O13-y) where B and B' represent multiple metal elements. This compositional parameter change enables sufficient oxide ion conductivity at lower operating temperatures compared to conventional YSZ materials

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by incorporating multiple metal elements (such as Mo, W, V, Ti, Nb, Ta) in the perovskite structure to create a composite oxide electrolyte. This composite approach achieves both high oxide ion conductivity and low-temperature operation by leveraging the synergistic effects of different metal oxides

Inventive Principle:
Principle #40Composite materials

2Power

If high operating temperature is required, then sufficient battery performance is achieved, but environment and space restrictions increase

Engineering Contradiction:
Improvebattery performanceVSAvoidapplication range
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

By changing the operating temperature parameter from high (700°C+) to low (below 700°C) through the use of hexagonal perovskite electrolytes, the patent expands the adaptability and versatility of solid electrolyte batteries, enabling applications in environments where high temperature operation is impractical or unsafe

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The proposed electrolyte achieves high electrical conductivity at lower temperatures, enabling efficient operation of SOFCs and other devices with fewer equipment constraints, expanding their usability and applicability.

Implementation Method 1

YSZ requires a high temperature of approximately 700°C or more in order to ensure the oxide ion conductivity necessary for the battery

Methodology Applied
Scientific EffectOxide ion conduction: Conduction (electrical)

Data Source

PatentEP3915936B1Solid electrolyte, electrolyte layer and battery
Publication Date: 2025.12.31 INSTITUTE OF SCIENCE TOKYO
  • EP3915936B1 patent drawingFigure 1
  • EP3915936B1 patent drawingFigure 2
  • EP3915936B1 patent drawingFigure 3

AI summary

A solid electrolyte having high electrical conductivity even in a low-temperature region is provided. A solid electrolyte containing a hexagonal perovskite-related compound, in which the compound is a compound represented by the following general formula (1), and an electrolyte layer and a battery using the solid electrolyte are disclosed. Ba7-αNb(4-x-y)Mo(1+x)MyO(20+z) ...(1), [in the formula (1), M is a cation of at least one element; α represents a Ba deficiency amount and represents a value of 0 or more and 0.5 or less, x represents a value of -1.1 or more and 1.1 or less, y represents a value of 0 or more and 1.1 or less, and z represents an oxygen non-stoichiometry and represents a value of -2.0 or more and 2.0 or less, provided that in the formula (1), |x| + y ≥ 0.01 is satisfied].