Mayenite Solid Electrolyte Doping for Higher Oxide Ion Conductivity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing mayenite-type compounds exhibit low oxide ion-conducting properties, limiting their application as solid electrolytes in SOFCs and SOECs, which require higher ion conductivity for efficient energy conversion and storage.

Innovation Solution

Incorporating lanthanum (La) and yttrium (Y) into mayenite-type compounds in specific mole percentages, along with optional titanium (Ti), to enhance the oxide ion conductivity by modifying the crystal structure and increasing the concentration of free oxide ions within the cages, thereby improving ion migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mayenite-type compounds are used as solid electrolytes, then they provide a crystal structure with free oxide ions in cages, but the oxide ion-conducting property is not very high (approximately 1/10 of YSZ)

Engineering Contradiction:

Improveoxide ion-conducting propertyVSAvoidion conduction efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the metal element M content within 0.4-5.3 mol% and optimizing the Ca/M ratio within 2.0-12.0. These parameter optimizations significantly improve oxide ion conductivity while maintaining the mayenite-type crystal structure with free oxide ions in cages, resolving the contradiction between structural integrity and ion conduction efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by incorporating metal elements M (selected from La, Y, Gd, Dy, Er, or Ho) into the mayenite-type compound Ca12Al14O33. This composite approach combines the advantageous cage structure of mayenite with the high ionic conductivity characteristics of metal-doped oxides, achieving oxide ion conductivity comparable to or exceeding traditional YSZ electrolytes

Inventive Principle:

Principle #40Composite materials

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 modified mayenite-type compounds demonstrate significantly higher oxide ion conductivity, enabling their use in high-temperature applications such as SOFCs and SOECs with enhanced power generation and electrolysis efficiency.

Implementation Method 1

operate by oxide ions being conducted through the solid electrolyte

Methodology Applied

Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

modifying the crystal structure and increasing the concentration of free oxide ions within the cages

Methodology Applied

Scientific EffectCrystal structure modification: Crystallisation

Data Source

PatentUS20240194919A1Oxide ion-conducting solid electrolyte

Publication Date: 2024.06.13 AGC INC

AI summary

An oxide ion-conducting solid electrolyte is provided. The oxide ion-conducting solid electrolyte contains a mayenite-type compound having a representative composition represented by Ca12Al14O33, and at least one metal element M selected from lanthanum (La) and yttrium (Y), wherein the metal element M is contained in a range of from 0.4 mol % through 5.3 mol % in terms of an oxide relative to the whole of the oxide ion-conducting solid electrolyte.