Bipolar Plate Weld Seam Arrangement for Electrochemical Device Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bipolar plates in electrochemical devices face issues with seam irregularities in weld seams, leading to leaks and media exchange between chambers and the surroundings, particularly at weld seam ends and beginnings, which compromise the tightness and sealing efficiency.
Innovation Solution
The weld seam arrangement includes a connecting weld seam that crosses the first and second medium channel weld seams, with its end or beginning positioned within or outside the medium-conducting regions, and is produced to cross these seams multiple times, ensuring that any irregularities do not result in fluid medium escape, and the weld seam configuration is optimized to lie within or outside the flow field sealing lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If weld seams are used to seal the coolant flow field, then the tightness between media chambers is improved, but seam irregularities at weld seam ends and beginnings cause leaks and media exchange
Solution Approach 1:
The patent applies preliminary action by extending the weld seam beyond the minimum required length to include ramp regions at the beginning and end. These extended portions are welded in advance to create gradual transitions that prevent seam irregularities and leaks at the weld seam ends, thereby ensuring reliable sealing before the main welding operation completes.
Solution Approach 2:
The patent changes the welding parameters by implementing ramp profiles (power ramps, speed ramps, and/or focus ramps) at the beginning and end of the weld seam. This gradual variation in welding parameters prevents sudden thermal shocks and creates smooth transitions, eliminating the seam irregularities that would otherwise cause leaks at weld seam ends.
2Manufacturing precision
If inlet regions and outlet regions with ramp profiles are provided to avoid seam irregularities, then weld seam quality is improved, but the welding process complexity increases
Solution Approach 1:
The patent segments the weld seam into distinct regions: a beginning ramp region, a middle constant section, and an end ramp region. Each segment has specific welding parameters optimized for its function, allowing the complex welding process to be broken down into manageable, repeatable sections that improve overall weld quality while maintaining process control.
3Reliability
If the connecting weld seam crosses medium channel weld seams multiple times, then leak prevention is improved, but the welding time and process complexity increase
Solution Approach 1:
The patent merges multiple welding operations into a single continuous welding pass. The connecting weld seam is welded in one continuous motion that crosses the medium channel weld seams multiple times, combining what would otherwise be separate welding operations into one efficient process that maintains reliable sealing while minimizing total welding time.
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 configuration effectively prevents leaks caused by weld seam irregularities, maintaining the tightness between media chambers and the surroundings, ensuring the integrity of the electrochemical device by positioning the weld seam ends and beginnings to avoid fluid medium escape into unintended chambers.
Implementation Method 1
the bipolar plate layers are connected to one another by means of the weld seams of the weld seam arrangement
Implementation Method 2
In a fusion welding method, in particular in a laser welding method
Data Source
AI summary
A bipolar plate for an electrochemical device, including a first bipolar plate layer and a second bipolar plate layer joined by a weld seam arrangement, wherein the first bipolar plate layer has a first and a second medium passage opening. The weld seam arrangement includes a first and a second medium channel weld seam, and a connecting weld seam which crosses the first and the second medium channel weld seams. Either a) the connecting weld seam is produced by a welding energy source which the first bipolar plate layer faced during the welding process, and the weld seam end of the connecting weld seam lies within the medium-conducting region of the bipolar plate which is surrounded by the first medium channel weld seam, and/or b) the connecting weld seam crosses the first medium channel weld seam and/or the second medium channel weld seam at least twice in each case.