Corrugated Fuel Electrode Structure for Dendrite-Resistant Metal-Air Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel electrodes for metal-air rechargeable power systems face challenges such as high cost, limited surface area to volume ratio, tortuous pore structures, and susceptibility to dendrite formation, which can lead to short circuits and reduced performance over time.
Innovation Solution
A corrugated fuel electrode structure comprising multiple electroconductive portions with offset corrugation axes, attached via discrete or continuous attachments, providing a high surface area to volume ratio, improved structural rigidity, and optimized electrolyte flow while minimizing dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If porous metal fuel electrodes are used to provide high surface area to volume ratio, then the surface area for fuel deposition is increased, but the structure becomes cost prohibitive and presents mass transport limitations due to tortuous pores
Solution Approach 1:
The fuel electrode is divided into multiple planar sheets with corrugated surfaces instead of using a monolithic porous structure. Each sheet contributes to the overall surface area while maintaining open, non-tortuous pathways for electrolyte flow between and among the sheets.
Solution Approach 2:
The electrode transitions from a two-dimensional planar structure to a three-dimensional corrugated structure with offset corrugation axes. This dimensional transformation increases surface area while preserving direct electrolyte access to all surfaces without requiring tortuous pore networks.
2Area of stationary object
If porous metal fuel electrodes are used to increase surface area, then more fuel deposition sites are available, but electrolyte flow is restricted and exchange rates are reduced
Solution Approach 1:
The electrode is segmented into multiple discrete corrugated sheets with spacing between them, creating open channels for electrolyte flow. This segmentation eliminates the tortuous pore restrictions while maintaining high total surface area through the stacked configuration.
Solution Approach 2:
By stacking corrugated sheets with offset axes, the design creates three-dimensional open pathways for electrolyte circulation. This allows electrolyte to access all electrode surfaces directly without navigating tortuous pores, significantly improving exchange rates.
3Reliability
If spacers are placed between fuel electrode and cathode to prevent shorting, then electrode stability is improved, but surface area available for reaction is reduced and electrolyte flow is hindered
Solution Approach 1:
The corrugated surfaces with their curved profiles inherently provide mechanical stability and resistance to bowing without requiring additional spacer components. The interlocking corrugation patterns between offset sheets create structural rigidity while maintaining open spaces for electrolyte flow and reaction areas.
4Ease of manufacture
If fuel electrode sheets are made thin to reduce cost, then material cost is reduced, but the sheets become susceptible to deflection and bowing that can cause short circuits
Solution Approach 1:
Corrugating thin sheets provides structural reinforcement through geometric curvature, dramatically increasing rigidity and resistance to deflection. The corrugated profile distributes mechanical stresses along the length of the sheets, preventing bowing and electrode contact even when using thin, cost-effective materials.
Solution Approach 2:
Dividing the electrode into multiple thin corrugated sheets with spacing between them creates a mechanically stable assembly. The offset corrugation axes cause the sheets to interlock, providing mutual support and preventing individual sheet deflection without requiring thick individual sheets or additional spacers.
Data Source
AI summary
A fuel electrode incorporates a first and second corrugated portion that are attached to each other at offset angles respect to their corrugation axis and therefore reinforce each other. A first corrugated portion may extend orthogonally with respect to a second corrugated portion. The first and second corrugated portions may be formed from metal wire and may therefore have a very high volumetric void fraction and a high surface area to volume ratio (sa/vol). In addition, the strands of the wire may be selected to enable high conductivity to the current collectors while maximizing the sa/vol. In addition, the shape of the corrugation, including the period distance, amplitude and geometry may be selected with respect to the stiffness requirements and electrochemical cell application factors. The first and second corrugated portions may be calendared or crushed to reduce thickness of the fuel electrode.