Fuel Cell Separator Titanium Carbide Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fuel cell separators with conductive carbon films on titanium substrates face issues with low sticking force, leading to oxidation of the interface and increased contact resistance under usage conditions.
Innovation Solution
A method involving a titanium substrate with projecting and recessed portions, where a carbon sheet is used for heat treatment to diffuse carbon and form a titanium carbide layer, enhancing the sticking force of the conductive carbon film through binding with the carbide layer, and further improved by plasma CVD for the conductive carbon film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive carbon film is formed on a titanium substrate surface, then electrical conductivity is improved, but the sticking force between the titanium substrate and the conductive carbon film becomes low
Solution Approach 1:
A titanium carbide layer is formed on the titanium substrate surface before forming the conductive carbon film. This preliminary action creates a bonding intermediate layer that enhances the sticking force between the titanium substrate and the subsequent conductive carbon film, preventing delamination while maintaining electrical conductivity.
Solution Approach 2:
The separator employs a composite structure consisting of a titanium substrate, a titanium carbide intermediate layer, and a conductive carbon film. This multi-layer composite material combines the advantages of each layer: the titanium substrate provides mechanical strength and corrosion resistance, the titanium carbide layer provides strong bonding and electrical conductivity, and the conductive carbon film provides high electrical conductivity and chemical stability.
2Ease of manufacture
If the sticking force between titanium substrate and conductive carbon film is low, then manufacturing is simpler, but the interface is easily oxidized and contact resistance increases under usage conditions
Solution Approach 1:
The titanium carbide layer is formed as a preliminary protective barrier on the titanium substrate surface before the conductive carbon film is applied. This intermediate layer prevents oxidation at the titanium-substrate interface and ensures long-term corrosion resistance under fuel cell operating conditions, while the overall structure remains manufacturable through established coating processes.
3Strength
If carbon is diffused into the titanium substrate to form titanium carbide layer, then sticking force is enhanced, but additional heat treatment process is required
Solution Approach 1:
The formation of the titanium carbide layer is merged with the existing heat treatment process used for other separator components. By combining the carbide layer formation with standard heat treatment procedures, the additional process complexity is minimized while achieving the desired sticking force enhancement through carbon diffusion into the titanium substrate.
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 enhances the corrosion resistance and reduces contact resistance with the power generation unit, ensuring improved reliability and performance of the fuel cell separator.
Implementation Method 1
performing a heat treatment on the titanium substrate in a state where a carbon sheet is brought in contact with the projecting portions such that carbon in the carbon sheet diffuses in the projecting portions
Implementation Method 2
performing a heat treatment on the titanium substrate in a state where a carbon sheet is brought in contact with the projecting portions
Data Source
AI summary
A method for manufacturing a fuel cell separator that ensures an improved corrosion resistance under usage environment of a fuel cell and restraining an increase of a contact resistance with a power generation unit by enhancing a sticking force of a conductive carbon film formed on a surface in contact with the power generation unit on a surface of a titanium substrate is provided. It is a method for manufacturing a fuel cell separator. The fuel cell separator includes a contact portion that is in contact with a power generation unit so as to partition the power generation units including electrodes of the fuel cell, and includes a conductive carbon film formed on the contact portion. First, a titanium substrate that has a plurality of projecting portions formed corresponding to a shape of the contact portion and recessed portions for gas flow channels formed between the projecting portions are prepared as a substrate of the separator. Next, a heat treatment is performed on the titanium substrate in a state where a carbon sheet is brought in contact with the projecting portions such that carbon of the carbon sheet diffuses in the projecting portions.