Metal-Supported Protonic Ceramic Cells With Diffusion Barrier Co-Sintering
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Solution Overview
Problem
The development of metal-supported protonic ceramic electrochemical cells faces challenges with co-sintering ceramic layers on stainless steel, as it requires a reducing atmosphere to prevent oxidation, leading to decomposition, oxygen non-stoichiometry, and undesirable interdiffusion between layers, which affects the stability and conductivity of the proton conductors.
Innovation Solution
The use of specific proton-conducting ceramics like LCN, which are compatible with co-sintering on stainless steel, and the implementation of sintering aids like LiF and manganese oxide to reduce sintering temperatures and minimize silicon and chromium diffusion, along with the introduction of a barrier layer to prevent element migration, enhances the densification and stability of the ceramic layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If co-sintering is performed in a reducing atmosphere to prevent oxidation of stainless steel, then oxidation resistance is improved, but decomposition and oxygen non-stoichiometry occur in proton-conducting ceramics
Solution Approach 1:
A barrier layer is applied to the stainless steel substrate before co-sintering to prevent oxidation of the metal and subsequent decomposition of the proton-conducting ceramic during the sintering process
Solution Approach 2:
A barrier layer acts as an intermediary between the stainless steel substrate and the proton-conducting ceramic, preventing direct interaction and element migration while allowing thermal contact during sintering
2Manufacturing precision
If co-sintering is performed at high temperatures to achieve proper densification, then densification is improved, but element migration and interdiffusion between layers increase
Solution Approach 1:
A barrier layer is introduced as an intermediary between the metal substrate and ceramic layers to prevent element migration and interdiffusion during high-temperature co-sintering
Solution Approach 2:
A composite structure consisting of a metal substrate, barrier layer, and proton-conducting ceramic is created to combine the advantages of both materials while mitigating their incompatibilities
3Stability of the object's composition
If conventional ceramic materials are used to maintain chemical stability, then stability is improved, but compatibility with metal support during co-sintering deteriorates
Solution Approach 1:
A barrier layer serves as a mediator that enables the use of chemically stable conventional ceramic materials by preventing direct harmful interactions with the metal support during co-sintering
Solution Approach 2:
The device is segmented into distinct layers (metal substrate, barrier layer, proton-conducting ceramic) that can be optimized independently, allowing conventional ceramics to be used without direct contact with the metal
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
This approach allows for the successful fabrication of metal-supported cells with improved conductivity and reduced element migration, achieving densification at lower temperatures and maintaining the integrity of the proton-conducting phases, thus overcoming the limitations of existing co-sintering methods.
Implementation Method 1
the implementation of sintering aids like LiF and manganese oxide to reduce sintering temperatures and minimize silicon and chromium diffusion
Implementation Method 2
the introduction of a barrier layer to prevent element migration
Implementation Method 3
Proton-conducting oxide ceramics are widely explored as alternatives to conventional oxide conductors, primarily because the proton conductors display higher conductivity at intermediate temperatures (400-600° C.)
Data Source
AI summary
This disclosure provides systems, methods, and apparatus related to metal-supported proton conducting solid oxide electrochemical devices. In one aspect, a method includes forming an electrode on a metal support of a device with a first proton-conducting ceramic. The metal support comprises an iron-chromium alloy. The first proton-conducting ceramic is in a powder form. An electrolyte layer is formed on the electrode and on the metal support of the device with a second proton-conducting ceramic. The second proton-conducting ceramic is in a powder form. The device is thermally treated at about 1200° C. to 1550° C.