Roll-to-Roll Carbon Strip Coating With Auxiliary Electrode Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for coating bipolar plates, electrodes, or electrical current collectors in electrochemical cells face challenges in achieving continuous, homogeneous, and high-quality carbon-based coatings that address both electrical conductivity and water removal, while avoiding issues like uneven coating, stress fractures, and high material loss, which are not adequately addressed by existing deposition processes.
Innovation Solution
A roll-to-roll process using a vacuum chamber with an auxiliary electrode and a grid- or strip-shaped element to create a potential-free strip coating, allowing for continuous and homogeneous deposition of carbon-based coatings on metallic substrates, utilizing a multi-chamber system for efficient exchange of targets and maintaining vacuum conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional batch coating processes are used, then coating quality can be maintained, but production time and cost increase significantly
Solution Approach 1:
The patent implements a continuous coating process where the substrate moves continuously through the coating chamber while receiving coating material, eliminating the batch-by-batch processing of conventional methods. This allows uninterrupted coating operation, significantly increasing production speed while maintaining consistent coating quality throughout the substrate surface.
Solution Approach 2:
The patent employs dynamic control of coating parameters during the continuous process, including adjustable substrate speed, variable coating material flux, and real-time monitoring of coating thickness. This dynamic adaptation ensures optimal coating quality is maintained despite the continuous operation, resolving the contradiction between speed and quality.
2Manufacturing precision
If high negative bias voltage is applied to improve coating homogeneity, then coating quality improves, but stress fractures and short circuits occur
Solution Approach 1:
The patent changes the electrical parameter regime by using low or zero negative bias voltage instead of high bias voltages. This parameter change achieves coating homogeneity through alternative mechanisms such as controlled material flux and substrate movement, avoiding the damaging effects of high voltage while maintaining coating quality.
Solution Approach 2:
The patent introduces an intermediary approach where coating homogeneity is achieved not through direct high-voltage ion bombardment but through controlled deposition conditions and substrate transport mechanisms. This intermediary method couples the benefits of uniform coating with substrate integrity by avoiding direct high-stress electrical fields.
3Reliability
If electric arc coating process is used for carbon coating, then electrical conductivity is improved, but uncontrolled arc movement causes inhomogeneous coating and increased material loss
Solution Approach 1:
The patent replaces the uncontrolled mechanical movement of electric arcs with a controlled system where coating material is delivered in a regulated manner. By substituting the arc-based mechanical process with a controlled deposition system, the patent achieves both electrical conductivity and coating homogeneity without the randomness of arc movement.
Solution Approach 2:
The patent implements feedback control mechanisms that monitor coating deposition in real-time and adjust material flux and substrate position accordingly. This feedback system ensures uniform coating distribution while maintaining the electrical conductivity benefits of carbon coating, preventing the inhomogeneity caused by uncontrolled arc movement.
4Manufacturing precision
If high electrical potential is applied to substrate for evaporation coating, then coating quality improves, but plant constraints and safety issues arise
Solution Approach 1:
The patent changes the electrical potential parameter from high voltage to low or zero voltage operation. This parameter change maintains coating quality through alternative controlled deposition mechanisms while eliminating the need for complex high-voltage equipment, safety systems, and vacuum technology infrastructure.
Solution Approach 2:
The patent employs a simpler, more accessible coating approach that does not require expensive high-voltage equipment and complex vacuum systems. By using a less complex process with readily available equipment, the patent reduces device complexity and safety concerns while still achieving effective carbon coating for bipolar plates.
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
Enables continuous production of high-quality, homogeneous carbon coatings with improved electrical conductivity and water removal capabilities, reducing material waste and process interruptions, and enhancing the substrate's service life and coating uniformity.
Implementation Method 1
A roll-to-roll process using a vacuum chamber with an auxiliary electrode and a grid- or strip-shaped element to create a potential-free strip coating, allowing for continuous and homogeneous deposition of carbon-based coatings on metallic substrates
Implementation Method 2
A roll-to-roll process using a vacuum chamber with an auxiliary electrode and a grid- or strip-shaped element
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
In this device, a ribbon-shaped substrate (1), arranged in a vacuum chamber (2) at a distance from and parallel to the longitudinal axis of a rod-shaped target (3a) made of metal or carbon, is coated. The target (3a) is negatively connected to a first electrical voltage source (4), and an anode (3b), also connected to the first voltage source (4), is arranged at a distance from the target (3a). The first voltage source (4) serves to ignite and maintain electrical arc discharges between the anode (3b) and the target (3a). At least one auxiliary electrode (6, 6a, 6b), connected to a positive terminal of a second voltage source (9), is arranged at a distance from the anode (3b), parallel to the target (3a), and between the substrate (1) and the target (3a).The target (3a) is arranged within legs of a v-shaped or u-shaped concave auxiliary electrode (6) or in a gap between two plate-shaped elements (6a, 6b) at a distance from the auxiliary electrode (6) or plate-shaped elements (6a, 6b) such that released ions are directed towards the ribbon-shaped substrate (1).