Electrolyte Membrane Composition for High Proton Conductivity
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Solution Overview
Problem
Existing electrolyte membranes with a perovskite-type ion conductor, such as BaZr1-xMxO3-α, exhibit low proton conductivity at temperatures between 500 and 700 degrees Celsius when the concentration of the trivalent substitution element M is uniform across crystal domains.
Innovation Solution
The electrolyte membrane is composed of multiple crystal domains with differing concentrations of the trivalent element M, specifically BaZr1-aYbaO3-δ and BaZr1-bYbbO3-δ, where a−b ≥ 0.28, resulting in enhanced proton conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the concentration of trivalent substitution element M is made uniform across crystal domains, then the manufacturing process is simplified, but the proton conductivity remains low
Solution Approach 1:
The patent applies local quality by creating crystal domains with different local concentrations of trivalent substitution element M. Specifically, it forms a core region with lower M concentration (0.05 ≤ x1 < x2 ≤ 0.40) surrounded by a shell region with higher M concentration, where each region has optimized local properties. This non-uniform local composition enables high proton conductivity while maintaining manufacturing feasibility through controlled solid solution formation.
Solution Approach 2:
The patent creates a composite electrolyte membrane structure consisting of multiple crystal domains with different M concentrations. Each domain acts as a distinct phase with optimized properties: the core region provides structural stability with lower M content, while the shell region enhances proton conductivity with higher M content. This composite approach at the crystal domain level achieves superior overall performance compared to uniform composition.
2Reliability
If the concentration of M is increased to enhance proton conductivity, then the proton conductivity improves, but the structural stability deteriorates
Solution Approach 1:
The patent resolves this contradiction by applying local quality through spatially differentiated M concentration. The core region maintains lower M concentration (0.05 ≤ x1 < 0.40) to preserve crystal structure stability and prevent excessive lattice distortion, while the surrounding shell region has higher M concentration (x2 ≤ 0.40) to maximize proton conductivity. This local optimization allows each region to fulfill its specific function without compromising the other.
Solution Approach 2:
The patent segments the crystal structure into distinct core and shell regions with different M concentrations. This segmentation allows the structure to simultaneously accommodate regions optimized for stability (core with lower M) and regions optimized for conductivity (shell with higher M). The segmented approach prevents the trade-off that would exist in a uniform structure by allowing independent optimization of each segment's composition.
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 membrane achieves high proton conductivity of 0.24 (10−2 s·cm−1) or more at temperatures between 500 and 700 degrees Celsius, surpassing the conductivity of membranes with uniform M concentrations.
Implementation Method 1
an electrolyte material having a proton conductivity, a perovskite-type ion conductor of which the chemical formula is BaZr1-xMxO3-α
Data Source
AI summary
The electrolyte membrane of the present disclosure includes a plurality of crystal domains. At least one of the crystal domains includes a first crystal subdomain and a second crystal subdomain. Each of the first crystal subdomain and the second crystal subdomain includes Ba, Zr, M, and O. M is a trivalent element. The concentration of M in the first crystal subdomain is different from the concentration of M in the second crystal subdomain.