Cladded Metallic Cathode Current Collector for High-Temperature Fuel Cells
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Solution Overview
Problem
Conventional fuel cell cathode current collectors suffer from severe corrosion due to the presence of electrolytes, leading to electrolyte loss and increased cell ohmic resistance, which existing solutions like thicker materials, stainless steel alloys, or conductive oxide coatings fail to adequately address, resulting in reduced power output and high costs.
Innovation Solution
A cladded metallic cathode current collector is developed using a composite material with a first metallic layer forming a conductive oxide corrosion layer and a second corrosion-resistant layer, reducing corrosion rates while maintaining low contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional cathode current collector material is used, then the fuel cell can be manufactured with standard materials, but severe corrosion occurs leading to electrolyte loss and reduced operational life
Solution Approach 1:
The patent applies composite materials by creating a bi-layer cladded structure where a first metal layer (such as stainless steel) is cladded with a second metal layer (such as nickel or nickel alloy). This composite structure combines the corrosion resistance of the first layer with the electrochemical stability and conductivity of the second layer, preventing severe corrosion and extending operational life beyond seven years while maintaining electrical performance.
2Strength
If the thickness of the cathode current collector is increased, then mechanical strength is improved, but corrosion-associated electrolyte loss is not addressed
Solution Approach 1:
Instead of simply increasing thickness, the patent uses a bi-layer composite structure where each layer has specific functional properties. The first layer provides mechanical strength and corrosion resistance, while the second layer provides electrochemical stability. This functional differentiation addresses electrolyte loss through the protective cladding mechanism rather than through increased thickness alone.
3Reliability
If Type 310 austenitic stainless steel is used, then corrosion resistance is improved, but oxide corrosion layer formation increases cell ohmic resistance
Solution Approach 1:
The patent combines Type 310 austenitic stainless steel as the first layer with a nickel or nickel alloy second layer. The stainless steel layer provides superior corrosion resistance, while the nickel layer forms a corrosion layer with sufficient electrical conductivity. This composite approach maintains low cell ohmic resistance while achieving the desired corrosion resistance, thereby preserving power output.
4Reliability
If an aluminum coating is applied, then corrosion protection is improved, but additional processing steps and high contact resistance are required
Solution Approach 1:
The patent uses a bi-layer metal cladding structure where both layers are metallic and can be bonded through standard metallurgical processes. This eliminates the need for aluminum coating processes, sanding steps, and associated capital investment in coating chambers. The metallic-clad structure achieves corrosion protection through the inherent properties of the cladded layers without requiring additional processing complexity.
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 a 30% or greater reduction in corrosion rate and maintains acceptable contact resistance, extending fuel cell operation beyond seven years and improving power output without the high costs associated with previous solutions.
Implementation Method 1
The first metallic layer is configured to form a conductive oxide corrosion layer in the presence of oxygen and/or molten carbonate electrolyte
Data Source
AI summary
A cathode current collector is made from a composite material including a first metallic layer made of a first metal and a second metallic layer made of a second metal different from the first metal. The first metallic layer is cladded with the second metallic layer. The first metallic layer is configured to form a conductive oxide corrosion layer in the presence of oxygen, molten carbonate electrolyte, or a combination thereof. The second metallic layer is corrosion resistant.