Laser-Treated Separator Plate Passivation for Low Contact Resistance
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Solution Overview
Problem
Metal separator plates in electrochemical systems face issues with corrosion resistance, increased electrical contact resistance due to passivation layers, and reduced service life under aggressive conditions, particularly in fuel cells.
Innovation Solution
A laser-surface-treated metal separator plate with a first passivation layer having an increased charge carrier density and minimal surface area change, created by laser treatment, which modifies the passivation layer to improve conductivity and reduce electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passivation layer is formed on metal separator plates to improve corrosion resistance, then corrosion resistance is improved, but electrical contact resistance increases significantly
Solution Approach 1:
The patent applies laser surface treatment to modify the passivation layer's parameters, specifically increasing charge carrier density by at least 10% while limiting surface area increase to no more than 5%. This parameter modification reduces electrical contact resistance while preserving the passivation layer's corrosion protection function.
Solution Approach 2:
The patent converts the harmful effect of the passivation layer (increased electrical resistance) into a beneficial effect by using laser treatment to create a modified passivation layer with enhanced charge carrier density. The same passivation layer that causes high resistance is transformed into a low-resistance conductive layer through laser-induced structural changes.
2Strength
If metal separator plates are used to improve mechanical stability and enable compact design, then mechanical stability is improved, but service life is reduced under aggressive reaction conditions
Solution Approach 1:
The laser surface treatment modifies the passivation layer's structural parameters, creating a more stable and corrosion-resistant surface layer. The increased charge carrier density and controlled surface area expansion enhance the passivation layer's stability under aggressive fuel cell operating conditions, thereby extending service life.
3Reliability
If the surface area of the passivation layer is increased to improve corrosion resistance, then corrosion protection is enhanced, but electrical conductivity deteriorates
Solution Approach 1:
The patent precisely controls the relationship between surface area and charge carrier density through laser treatment. By limiting surface area increase to no more than 5% while increasing charge carrier density by at least 10%, the patent achieves improved corrosion protection without significantly compromising electrical conductivity.
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 laser-treated passivation layer enhances electrical conductivity and reduces electrical contact resistance, potentially extending the service life and reducing production costs of electrochemical systems.
Implementation Method 1
a first passivation layer which, as a result of the laser surface treatment, has a charge carrier density that is increased by at least 10%
Data Source
AI summary
A metal separator plate for an electrochemical system, having at least a first laser-surface-treated region with a first passivation layer and a second region with a native or reconstructed passivation layer, wherein, as a result of the laser surface treatment, the first passivation layer has: a charge carrier density that is increased by at least 10%, and a surface area that is no more than 5% larger in relation to the native or reconstructed passivation layer. The present disclosure further relates to methods for producing and characterizing such a separator plate.