BaZrO3 Proton Conductor Grain Boundary Resistance

Solution Overview

Problem

BaZrO3-based proton conductors exhibit increased entire resistance due to higher resistance in crystal grains when Zr is substituted by In, leading to higher electrical conductivity in crystal grain boundaries, which complicates their application in solid oxide fuel cells.

Innovation Solution

A proton conductor with a composition formula of BaZr1-x-yYxIny, where 0<y≤0.013, 0<x+y<0.5, and 0<x<0.5, is developed, allowing for a low entire resistance and high proton conductivity by adjusting the amount of In added to decrease the resistance of crystal grain boundaries and compensate for increased resistance in crystal grains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Zr is substituted by In in BaZrO3-based proton conductor, then proton conductivity in crystal grains is improved, but resistance in crystal grain boundaries increases

Engineering Contradiction:

Improveproton conductivityVSAvoidresistance in crystal grain boundaries

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by introducing In specifically at crystal grain boundaries through controlled substitution (0 < y ≤ 0.013 in the formula BaZr1-x-yYxInyO3). This localized In addition modifies the chemical composition and electrical properties specifically at the grain boundary regions, reducing their resistance without significantly affecting the bulk crystal grain properties. The spatially selective doping achieves different local characteristics: high proton conductivity in grains and low resistance at boundaries.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by precisely controlling the In substitution parameter y within a specific range (0 < y ≤ 0.013). By adjusting this compositional parameter, the electrical resistance at crystal grain boundaries is optimized. The patent demonstrates that within this parameter range, the grain boundary resistance is sufficiently reduced while maintaining high proton conductivity, achieving the best overall performance.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If Y substitution is increased to improve proton conductivity, then electrical conductivity increases, but crystal grain size decreases

Engineering Contradiction:

Improveelectrical conductivityVSAvoidcrystal grain size

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent employs parameter changes by precisely controlling the In substitution parameter y within a specific range (0 < y ≤ 0.013). By adjusting this compositional parameter, the electrical resistance at crystal grain boundaries is optimized. The patent demonstrates that within this parameter range, the grain boundary resistance is sufficiently reduced while maintaining high proton conductivity, achieving the best overall performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system with dual substitution: Y substitution (x parameter) for improving proton conductivity in the bulk and In substitution (y parameter) for reducing grain boundary resistance. The combined effect of these two substitutions synergistically addresses both the conductivity and grain size issues, achieving superior overall performance compared to single substitution systems.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentEP3096329B1Proton conductor

Publication Date: 2019.12.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

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AI summary

A proton conductor is a proton conductor represented by a composition formula of BaZr1-x-yYxInyO3, and x and y in the composition formula satisfy 0<y≤0.013 and 0<x+y<0.5.