Ceria Electrolyte Low-Temperature Sintering
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Solution Overview
Problem
Current solid oxide fuel cells require high sintering temperatures for ceria-based electrolytes, leading to increased processing time and cost, and potential reactions between ceria-based electrolytes and MIEC cathodes, which degrade power density.
Innovation Solution
A ceria electrolyte doped with Gd or Sm and a small amount of Yb and Bi to achieve low-temperature sintering properties, maintaining high oxygen ionic conductivity and preventing cation radius increase, allowing for simultaneous thermal treatment with cathodes at lower temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high sintering temperature is used for ceria-based electrolyte, then high sintering density is achieved, but processing time increases and cost increases
Solution Approach 1:
The patent changes the chemical composition parameters of the ceria electrolyte by doping with specific amounts of Gd (5-15 mol%), Sm (5-15 mol%), Yb (0.1-5 mol%), and Bi (0.1-5 mol%). This parameter modification enables the electrolyte to achieve high sintering density (≥95%) at reduced sintering temperatures (1000-1200°C), thereby shortening processing time while maintaining manufacturing precision
Solution Approach 2:
The patent creates a composite doped ceria electrolyte material combining multiple dopants (Gd/Sm, Yb, and Bi) with ceria base material. This composite structure synergistically improves sintering characteristics, allowing dense microstructure formation at lower temperatures and reducing overall processing time
2Manufacturing precision
If high sintering temperature is used for ceria-based electrolyte, then high sintering density is achieved, but manufacturing cost increases
Solution Approach 1:
The patent modifies compositional parameters by optimizing dopant concentrations (Gd: 5-15 mol%, Sm: 5-15 mol%, Yb: 0.1-5 mol%, Bi: 0.1-5 mol%) to enable low-temperature sintering (1000-1200°C) that achieves ≥95% density. This reduces energy consumption and manufacturing cost while maintaining high sintering density
Solution Approach 2:
The patent applies local quality enhancement through targeted doping strategies where Yb and Bi dopants specifically address sintering behavior at grain boundaries and local regions, enabling dense microstructure formation at lower temperatures and reducing overall manufacturing cost
3Reliability
If conventional ceria electrolyte is used, then oxygen ionic conductivity is maintained, but thermal treatment temperature must be high causing reactions with MIEC cathode
Solution Approach 1:
The patent changes the thermal treatment temperature parameter from conventional high temperatures (1300°C or higher) to reduced temperatures (1000-1200°C) through compositional modification with Gd/Sm, Yb, and Bi dopants. This temperature reduction prevents harmful reactions with MIEC cathodes while maintaining oxygen ionic conductivity through optimized dopant concentrations
Solution Approach 2:
The patent introduces Yb and Bi dopants as intermediary elements that mediate between the ceria electrolyte and MIEC cathode. These dopants modify the thermal and chemical properties of the electrolyte, creating a buffer effect that prevents direct harmful reactions with the cathode at the interface
4Temperature
If Yb and Bi are co-doped in ceria electrolyte, then low-temperature sintering is achieved, but cation radius may increase
Solution Approach 1:
The patent optimizes dopant concentration parameters to balance two competing effects: Yb (smaller ionic radius) counteracts the radius-increasing effect of Bi (larger ionic radius). By controlling Yb and Bi concentrations within specific ranges (0.1-5 mol% each), the patent achieves low-temperature sintering while maintaining stable average cation radius and preventing excessive lattice expansion
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 solution enables high sintering density and improved power characteristics of solid oxide fuel cells by reducing thermal treatment temperatures, shortening processing time, and preventing undesirable reactions, thereby enhancing power density and efficiency.
Implementation Method 1
a positive electrode, a solid electrolyte membrane formed through co-sintering with the positive electrode, and a negative electrode
Implementation Method 2
co-sintering the positive electrode and the solid electrolyte membrane with each other, thereby forming a positive electrode-supported solid oxide fuel cell
Data Source
AI summary
Disclosed is a ceria electrolyte for a solid oxide fuel cell, which is a ceria (CeO2) electrolyte configured such that either gadolinium (Gd) or samarium (Sm) is co-doped with ytterbium (Yb) and bismuth (Bi), wherein Bi is doped in an amount of 0.5 to 5 mol %, thus exhibiting low-temperature sintering properties.