Concavo-Convex Ion Exchange Membrane for Low-Resistance Ion Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ion exchange membranes face challenges in increasing effective membrane area, reducing average electric resistance, preventing contaminant attachment, and maintaining mechanical strength, especially when subjected to varying salt concentrations.
Innovation Solution
The development of an ion exchange membrane with a concavo-convex shape formed by curving the membrane itself to create convex and concave parts, which is manufactured through methods involving curving and graft polymerization or thermal polymerization of a nonporous or porous base material, enhancing the membrane's effective surface area and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interval between CEM and AEM is narrowed to decrease electric resistance of the flow passage, then electric resistance decreases, but membrane pollutants block the flow passage and power output decreases
Solution Approach 1:
The flow passage spacer is designed with a convex part that protrudes toward the CEM, creating a curved surface geometry. This convex structure reduces the effective contact area between the spacer and membrane, preventing pollutant aggregation while maintaining a narrow interval to decrease electric resistance. The curved surface allows ions to flow more smoothly without being blocked by flat spacer surfaces.
Solution Approach 2:
The flow passage spacer has different structural characteristics at different locations: a convex part facing the CEM with reduced contact area, and other portions maintaining standard spacer functions. This local differentiation allows the spacer to simultaneously achieve low electric resistance through narrow spacing while preventing pollutant blockage at the critical membrane interface region.
2Productivity
If the interval between CEM and AEM is narrowed to increase power generation efficiency, then efficiency increases, but pump dynamic electric power increases due to elevated supply pressure
Solution Approach 1:
The convex part of the flow passage spacer creates a curved flow path that reduces turbulence and pressure loss. By maintaining a narrow interval with a curved geometry rather than a flat one, the system achieves better power generation efficiency while minimizing the pressure increase that would require additional pump energy.
3Ease of operation
If conventional spacers with spacer mesh are used, then flow distribution is improved, but effective membrane area decreases due to ion diffusion inhibition near spacer mesh
Solution Approach 1:
The invention removes the spacer mesh component from the flow passage spacer, retaining only the gasket structure with a convex part. This extraction eliminates the ion diffusion-inhibiting mesh while preserving the flow distribution function through the convex geometry that guides flow uniformly across the membrane surface.
Solution Approach 2:
The convex part of the gasket creates a curved surface that improves flow distribution across the membrane while maintaining a larger effective membrane area compared to flat spacers with mesh. The curved geometry promotes uniform flow without creating stagnant regions where ions would be inhibited from diffusing.
4Area of stationary object
If ion exchange membrane has increased surface area for ion permeation, then ion permeation efficiency increases, but mechanical strength and structural stability decrease
Solution Approach 1:
The convex part of the flow passage spacer creates a curved interface with the membrane, which increases the effective permeation area through the curved surface while the gasket structure provides mechanical support that maintains structural stability and prevents membrane deformation.
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 concavo-convex shaped membrane effectively increases ion permeation area, reduces electric resistance and contaminant attachment, and maintains structural integrity across varying salt concentrations, thereby improving the efficiency and durability of power generation systems.
Implementation Method 1
CEM is characterized by being selectively permeated by cations, while AEM is characterized by being selectively permeated by anions. The cations pass through CEM and cannot pass through AEM, and the anions pass through AEM and cannot pass through CEM.
Implementation Method 2
The ion exchange membrane has a concavo-convex shape, wherein the ion exchange membrane has flat portions in the vicinity of ends, and convex curves and concave curves resulting from curvatures of the ion exchange membrane itself form convex parts and concave parts, respectively
Implementation Method 3
the convex part has an apex and a side face in the longitudinal direction, and the side face is inclined from the apex toward the first concave part
Implementation Method 4
the concave parts between the convex parts are flat... can properly decrease average electric resistance of the membrane and the attachment of a contaminating substance
Data Source
AI summary
A problem to be solved by the present invention is to provide an ion exchange membrane that can increase the surface area of a membrane effective for ion permeation, properly decreases the electric resistance of a flow passage between membranes and the attachment of a contaminating substance thereto, also enhances the mechanical strength of the membrane itself, and further, is less deformed or damaged due to swelling over a wide range of salt concentrations and even if there is a large difference in salt concentration between two solutions contacted with the membrane. The present invention provides an ion exchange membrane having a concavo-convex shape, wherein the ion exchange membrane has a flat portion in the vicinity of ends, and a convex curve and a concave curve resulting from curvatures of the ion exchange membrane itself form a convex part and a concave parts, respectively, in the concavo-convex shape of the ion exchange membrane, wherein the convex part extends linearly or curvedly, the concave part between the convex parts is flat, the concave part includes a first concave part adjacent to the convex part in the lateral direction of the convex part, along the longitudinal direction of the convex part, the convex part has an apex and a side face in the longitudinal direction, and the side face is inclined from the apex toward the first concave part.