Catalyst-Coated Membrane Manufacturing with Suction Support
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Solution Overview
Problem
The manufacturing of catalyst-coated membranes for fuel cells faces challenges due to the electrolyte membrane's tendency to swell and shrink, leading to creases and pinholes during the application and drying of electrode ink, which reduces fuel cell performance.
Innovation Solution
A manufacturing apparatus and method that uses a suction roller to support the thin film, applies a coating liquid, and includes a drying system with sequential temperature zones and heat-shielding zones to prevent deformation, along with an attachment mechanism for supporting members to maintain film stability throughout the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the electrolyte membrane is simply suspended on a backup roller during coating, then the coating process is simple, but the membrane may be displaced from the shape-retaining film during coating when using solvents that cause significant swelling
Solution Approach 1:
A shape-retaining film is introduced as an intermediary layer between the electrolyte membrane and the backup roller. This film provides the necessary support and stability during coating while allowing the membrane to maintain its position without direct contact with the roller, preventing displacement even when solvents cause swelling.
Solution Approach 2:
The support system is segmented into multiple components: the backup roller provides overall support, while the shape-retaining film provides localized support at critical positions. This segmentation allows each component to perform its specific function optimally - the roller for stability and the film for shape maintenance.
2Manufacturing precision
If the electrolyte membrane is sucked by a roller during coating, then deformation due to swelling is prevented, but the membrane may still undergo swelling and shrinkage when separated from the roller after coating
Solution Approach 1:
The shape-retaining film is attached to the membrane before coating, performing preliminary support and stabilization. This preliminary action ensures the membrane maintains its shape during the coating process and continues to provide support after coating, preventing post-coating swelling and shrinkage issues.
Solution Approach 2:
The mechanical support conditions are changed by introducing the shape-retaining film, which alters the physical state and stability characteristics of the membrane system. This parameter change in the support mechanism prevents both during-coating deformation and post-coating instability.
3Manufacturing precision
If the electrode ink is applied while the electrolyte membrane is sucked by the roller, then deformation due to swelling is inhibited, but the membrane may undergo swelling and shrinkage caused by solvent absorption and drying after separation
Solution Approach 1:
The shape-retaining film acts as an intermediary that provides continuous support throughout the coating and drying processes. It mediates between the solvent-induced swelling forces and the membrane structure, preventing both during-coating deformation and post-coating swelling/shrinkage by maintaining structural integrity.
Solution Approach 2:
The shape-retaining film provides beforehand cushioning by being attached prior to coating. It cushions against the harmful effects of solvent absorption and drying shrinkage, preventing damage before it occurs during the coating and subsequent drying processes.
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 effectively inhibits deformation and prevents the generation of creases and pinholes, ensuring consistent fuel cell performance by maintaining the electrolyte membrane's integrity during and after coating.
Implementation Method 1
a suction roller that sucks and supports the thin film on an outer surface thereof
Implementation Method 2
a drying part that is provided to cover a portion of the outer surface of the suction roller and dries the coating liquid applied to the one side of the thin film to form the functional layer
Data Source
AI summary
An electrolyte membrane with a backsheet is sent out from an electrolyte membrane unwinding roller, and is separated with its second side sucked on a suction roller by a first press roller. While the electrolyte membrane from which the backsheet has been separated is transported with the electrolyte membrane sucked and supported on the suction roller, an electrode ink is applied to a first side of the electrolyte membrane to form an electrode ink layer, which is dried by blowing hot air thereto to form a catalyst layer. Thereafter, in a state in which the outer surface of a second press roller disposed close to the suction roller is in contact with and supported on the first side of the electrolyte membrane, a support film is pressed against the second side of the electrolyte membrane by a third press roller and attached thereto to manufacture a catalyst-coated membrane.