Solid Oxide Cell Barrier Layer Against La2Zr2O7 Resistance
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Solution Overview
Problem
The formation of high resistance phases such as La2Zr2O7 during the manufacture of solid oxide electrochemical cells can lead to deteriorated cell performance, especially when using lanthania-cobalt based oxides for oxygen electrodes and zirconia-based electrolytes.
Innovation Solution
A porous barrier-layer made of doped ceria with a thickness of 100µm or greater and 500µm or less and a porosity of greater than 10% is introduced between the electrolyte and the oxygen electrode to prevent the formation of high resistance phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LaCoO3-based oxide is used for the oxygen electrode to achieve higher electric conductivity and catalytic activity, then the electrode performance is improved, but the reactivity with ZrO2-based electrolyte increases leading to high resistance phase formation
Solution Approach 1:
The patent introduces a porous barrier-layer made of doped ceria as an intermediary layer between the LaCoO3-based oxygen electrode and the ZrO2-based electrolyte. This intermediary layer physically separates the two reactive materials, preventing direct contact and the formation of high resistance phases (such as La2Zr2O7) while still allowing ionic transport necessary for cell operation.
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 implementation of the porous barrier-layer effectively suppresses the diffusion of components between the electrolyte and the oxygen electrode, thereby improving the cell performance by maintaining high current density and reducing pressure loss.
Implementation Method 1
suppresses the diffusion of components between the electrolyte and the oxygen electrode
Data Source
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AI summary
An electrochemical cell according to an embodiment includes a hydrogen electrode, an electrolyte laminated on the hydrogen electrode, a barrier-layer laminated on the electrolyte, and an oxygen electrode laminated on the barrier-layer. The barrier-layer has a porous structure having a thickness of greater than 20 µm and a porosity of greater than 10%.