LTCC-Compatible SOFC Electrolyte Composition for Leak-Resistant Sealing
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Solution Overview
Problem
Conventional solid oxide fuel cells (SOFCs) face compatibility issues between their ceramic electrolytes and stainless steel casings, leading to improper sealing, gas leakage, and reduced efficiency due to mismatched thermal expansion coefficients and chemical incompatibilities.
Innovation Solution
A conductive SOFC electrolyte composition comprising 73 wt% to 77.5 wt% gadolinium doped ceria and 22.5 wt% to 27 wt% glass composite, with 95 wt% to 99 wt% bismuth oxide and 1 wt% to 5 wt% potassium oxide, is developed, which is physically and chemically compatible with low temperature co-fired ceramic (LTCC) casing materials, allowing for lower sintering temperatures and reduced warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional ceramic electrolytes are used in SOFCs, then high temperature operation is achieved, but compatibility issues with stainless steel casings occur due to mismatched thermal expansion coefficients
Solution Approach 1:
The patent modifies the thermal expansion coefficient parameter of the electrolyte by using gadolinium doped ceria (GDC) with specific doping concentrations (10-30 mol% GdO1.5), which adjusts the TEC to match LTCC casing materials, thereby resolving the sealing compatibility issue while maintaining high temperature operation
Solution Approach 2:
The patent employs a composite electrolyte material consisting of ceria-based ceramic doped with gadolinium, combining the high temperature stability of ceria with the thermal expansion characteristics of GDC, creating a material that simultaneously achieves high operating temperature and compatibility with LTCC casings
2Power
If high temperature operation is maintained for optimal conductivity, then electrical performance is improved, but chemical incompatibilities and gas leakage increase
Solution Approach 1:
The patent optimizes the operating temperature parameter within a specific range (600-800°C) where the GDC electrolyte exhibits sufficient ionic conductivity while minimizing chemical reactions with casing materials, thereby achieving optimal power output without excessive gas leakage
Solution Approach 2:
The patent uses LTCC casing materials that can withstand the operating conditions and provide long-term sealing, replacing conventional stainless steel casings that fail under thermal stress, thus preventing gas leakage throughout the operational lifetime of the fuel cell
3Stability of the object's composition
If traditional electrolyte compositions are used, then high temperature stability is achieved, but integration with LTCC casing materials becomes difficult
Solution Approach 1:
The patent adjusts the thermal expansion coefficient parameter of the electrolyte to match LTCC materials through controlled gadolinium doping, enabling the electrolyte and casing to undergo coordinated thermal expansion and contraction during co-firing, thus facilitating easy integration while maintaining thermal stability
Solution Approach 2:
The patent combines the electrolyte fabrication process with the LTCC casing firing process, allowing both components to be sintered simultaneously at compatible temperatures, thereby simplifying manufacturing and ensuring perfect integration between electrolyte and casing
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 achieves higher efficiency, minimizes gas leakage, extends the life of SOFCs, and enables reduced dimensions by matching the thermal expansion coefficients and shrinkage of the electrolyte with the LTCC casing, resulting in improved sealing and operational performance.
Implementation Method 1
Gadolinium doped Ceria (GDC) together with a relatively low temperature melting, ionic conducting glass
Implementation Method 2
a relatively low temperature melting, ionic conducting glass
Implementation Method 3
ionic conducting glass
Implementation Method 4
matching the thermal expansion coefficients and shrinkage of the electrolyte with the LTCC casing
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present disclosure relates to a conductive Solid Oxide Fuel Cell (SOFC) electrolyte composition that is compatible with Low Temperature Co-fired Ceramic (LTCC). The conductive SOFC electrolyte composition comprises gadolinium doped ceria, glass composite and additives. The conductive SOFC electrolyte composition is physically and chemically compatible with the LTCC. A process for preparing a conductive SOFC electrolyte composition is also provided in the present disclosure.