Perovskite Membrane Electrode Assembly for Stable PCFC Interface Bonding

Solution Overview

Problem

In solid oxide fuel cells (SOFCs) and proton ceramic fuel cells (PCFCs), the interface between the air electrode and the electrolyte membrane experiences bonding failures due to differences in thermal expansion coefficients, leading to increased ohmic resistance and the risk of electrode peeling.

Innovation Solution

A membrane electrode assembly is developed, comprising a first electrode with a first perovskite compound and a second perovskite compound formed of Ba, Zr, Yb, one or more transition elements including Co, and O, which reduces ohmic resistance and maintains bonding at the interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a typical air electrode material (e.g., LaSrCoFe composite oxide) with high thermal expansion coefficient is used, then the electrode material can be effectively utilized for its electrochemical function, but the difference in thermal expansion coefficient between the air electrode and electrolyte increases, leading to bonding failure and electrode peeling at the interface

Engineering Contradiction:

Improveelectrochemical functionVSAvoidinterface bonding

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies composite materials by creating a multi-component air electrode system consisting of a proton-conductive perovskite oxide (BaZr1-x-yCexMxO3-δ where M is a first transition element), an SOFC air electrode material, and an auxiliary oxide. This composite structure combines materials with different thermal expansion coefficients to reduce the overall difference between electrode and electrolyte, preventing interface bonding failure while maintaining electrochemical functionality. The specific example uses BaZr0.4Ce0.4M0.2O3-δ combined with LaSrCoFeO3-δ and auxiliary oxide to achieve both compatibility and performance.

Inventive Principle:

Principle #40Composite materials

2Device complexity

If conventional SOFC air electrode materials are used in PCFC, then the design can be simplified, but bonding failure at the interface increases due to large thermal expansion coefficient difference, leading to increased ohmic resistance

Engineering Contradiction:

Improvecell designVSAvoidinterface bonding

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies composite materials by creating a multi-component air electrode system consisting of a proton-conductive perovskite oxide (BaZr1-x-yCexMxO3-δ where M is a first transition element), an SOFC air electrode material, and an auxiliary oxide. This composite structure combines materials with different thermal expansion coefficients to reduce the overall difference between electrode and electrolyte, preventing interface bonding failure while maintaining electrochemical functionality. The specific example uses BaZr0.4Ce0.4M0.2O3-δ combined with LaSrCoFeO3-δ and auxiliary oxide to achieve both compatibility and performance.

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 proposed membrane electrode assembly effectively suppresses the increase in ohmic resistance and maintains interface bonding, thereby enhancing the performance and reliability of PCFCs.

Implementation Method 1

an increase in ohmic resistance due to the bonding failure at the interface between the electrolyte membrane and the electrode is problematic

Methodology Applied

Scientific EffectOhmic resistance: Electrical Resistance

Implementation Method 2

since a different in thermal expansion coefficient between an air electrode material and an electrolyte constituting an electrolyte membrane is large, a stress is likely to be accumulated at the interface between materials

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS20250030028A1Membrane electrode assembly, electrochemical cell, and fuel cell system

Publication Date: 2025.01.23 PANASONIC HOLDINGS CORP

AI summary

A membrane electrode assembly of the present disclosure is a membrane electrode assembly including a first electrode and an electrolyte membrane that contains an oxide having proton conductivity, in which the first electrode contains a first oxide and a second oxide, the first oxide is a first perovskite compound represented by Compositional Formula ABO3, where in the first perovskite compound, constituent elements of an A site include at least one selected from the group consisting of La, Sr, and Ba, and constituent elements of a B site include at least one selected from the group consisting of Co and Fe, and the second oxide is a second perovskite compound formed of Ba, Zr, Yb, one or more of first transition elements including at least Co, and O.