Fuel Cell Separator Coating for Corrosion Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell separators with metal substrates face corrosion issues during power generation, leading to increased contact resistance due to moisture and potential differences, which existing coatings like diamond-like carbon and noble metals are unable to effectively mitigate.
Innovation Solution
A fuel cell separator with a coating layer comprising an amorphous carbon layer and conductive graphite sections, where the graphite sections are partially exposed and dispersed as islands, and a titanium layer is used between the metal substrate and the coating layer to enhance corrosion resistance and reduce contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal substrate is used for the fuel cell separator, then mechanical strength and moldability are improved, but corrosion resistance deteriorates due to moisture and potential differences during power generation
Solution Approach 1:
The patent applies composite materials by combining a metal substrate with a carbon coating layer. The metal substrate provides mechanical strength and moldability, while the carbon coating layer provides corrosion resistance. This composite structure resolves the contradiction between mechanical strength and corrosion resistance by integrating the advantages of both materials.
Solution Approach 2:
The carbon coating layer acts as an intermediary between the metal substrate and the corrosive environment. It protects the metal substrate from direct contact with moisture and electrolytes, thereby preventing corrosion while allowing the metal substrate to maintain its structural integrity and mechanical properties.
2Reliability
If a noble metal plating is applied to suppress corrosion, then corrosion resistance is improved, but manufacturing cost increases due to the expensive noble metals
Solution Approach 1:
The patent replaces expensive noble metal plating with a carbon-based coating that is significantly cheaper to manufacture. The carbon coating provides sufficient corrosion protection without requiring costly noble metals, thereby reducing manufacturing cost while maintaining adequate corrosion resistance for the fuel cell separator.
Solution Approach 2:
The patent changes the material parameter from noble metal to carbon-based material. This parameter change maintains the protective function against corrosion while dramatically reducing the cost associated with noble metal materials and processing.
3Reliability
If a graphite layer is formed on the metal substrate to suppress corrosion, then corrosion resistance is improved, but manufacturing difficulty increases due to technical challenges in formation
Solution Approach 1:
The patent changes the formation method parameters by using chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD) processes. These parameter changes enable the graphite layer to be formed under controlled conditions with better adhesion and uniformity, reducing the technical difficulty compared to conventional methods.
Solution Approach 2:
The patent replaces mechanical or physical coating methods with chemical vapor deposition processes. This substitution allows for more uniform and controlled formation of the graphite layer, improving manufacturability while maintaining effective corrosion protection.
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 effectively suppresses corrosion of the metal substrate and inhibits the increase in contact resistance even in harsh fuel cell power generation environments, maintaining performance and longevity.
Implementation Method 1
a first aspect of the present invention as set forth in claim 1 is directed to a fuel cell separator which has a coating layer on a metal substrate
Data Source
Figure 1
Figure 2
Figure 3A~3D
AI summary
Provided is a fuel cell separator having a coating layer (24) on a metal substrate (22). The coating layer (24) is provided with an amorphous carbon layer (26) and a conductive section (28). The conductive section (28) is composed of graphite particles, which are preferably dispersed in the manner of islands each of which has at least a part exposed from the surface of the amorphous carbon layer (26).