Fuel Cell Bipolar Plate Coating for Gas-Tight Corrosion Resistance
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Solution Overview
Problem
Bipolar plates in fuel cells face challenges in achieving high gas-tightness and elasticity while maintaining corrosion resistance and contact conductivity, as existing solutions often compromise on these properties or complicate the manufacturing process.
Innovation Solution
A method involving a conductive core with a first titanium nitride layer for low surface contact resistance, followed by a ceramic oxide-metal second layer for corrosion resistance and gas-tightness, formed through thermolysis of metalorganic compounds, ensuring the integrity of the bipolar plate under deformations and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer-based corrosion-resistant coating is applied over a metal-containing coating, then gas-tightness and elasticity are improved, but corrosion resistance and contact conductivity deteriorate
Solution Approach 1:
The coating is divided into multiple functional layers: a metal-containing layer (titanium nitride) providing corrosion resistance and conductivity, and a polymer-based layer providing gas-tightness and elasticity. Each layer performs its specific function without compromising the other, resolving the contradiction between gas-tightness and corrosion resistance.
Solution Approach 2:
The bipolar plate uses a composite coating structure combining inorganic metal-containing coating and organic polymer-based coating. This composite approach allows the system to simultaneously achieve corrosion resistance from the metal layer and gas-tightness with elasticity from the polymer layer, eliminating the need to compromise one property for another.
2Object-affected harmful factors
If metal particles are introduced into the polymer-based coating to enhance conductivity, then contact conductivity is improved, but the manufacturing process becomes more complex
Solution Approach 1:
Instead of using expensive and complex metal particle incorporation processes, the patent employs a simpler alternative: a thin metal-containing coating layer (titanium nitride) applied directly to the bipolar plate surface. This layer provides the necessary conductivity without requiring additional metal particles or complex manufacturing steps, effectively replacing the complicated approach with a more efficient one.
3Reliability
If the metal-containing coating is made thin with amorphous structure to provide smoothness and uniformity, then gas-tightness is improved, but corrosion resistance and contact conductivity deteriorate
Solution Approach 1:
The coating functionality is segmented between two distinct layers: the metal-containing layer (titanium nitride) with optimized thickness for corrosion resistance and conductivity, and the polymer-based layer providing gas-tightness. This segmentation allows each layer to be optimized for its specific function without compromising the other, resolving the contradiction between gas-tightness and corrosion resistance.
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 high gas-tightness and elasticity without compromising corrosion resistance and contact conductivity, meeting the requirements for fuel cell performance and durability.
Implementation Method 1
a ceramic oxide-metal second layer for corrosion resistance and gas-tightness, formed through thermolysis of metalorganic compounds
Data Source
AI summary
The disclosure relates to bipolar plates used in fuel cells and to methods for forming bipolar plates. A bipolar plate of a fuel cell with a composite corrosion-resistant, gastight, conductive coating comprises a core of a required shape, a first layer having high contact conductivity on the core, and a second layer having corrosion resistance, high gas-tightness, electric conductivity on the first layer and in pores of the first layer, the second layer covering at least the pores in the first layer. The first layer is preferably formed by a magnetron sputtering method, and the second layer is preferably formed by a method of thermolysis of a metalorganic compound. This ensures high gas-tightness and elasticity of a bipolar plate without compromising its corrosion resistance and contact conductivity.