Redox Flow Battery Electrodes with Surface Elevations
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Solution Overview
Problem
Redox flow batteries face inefficiencies due to the hydrogen formation reaction at conventional carbon or graphite electrodes, leading to unequal charge ratios and reduced Faraday efficiency, which limits their ability to store energy effectively from renewable sources.
Innovation Solution
The use of electrodes with elevations made from materials like lead, bismuth, zinc, titanium, or tungsten, which have a lower overvoltage potential for hydrogen evolution, combined with a membrane-separated chamber design and flow channels, enhances the surface area and reduces the hydrogen evolution reaction, thereby improving Faraday efficiency and overall battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional carbon or graphite electrodes are used, then the electrode structure provides maximum surface area, but the hydrogen formation reaction occurs leading to reduced Faraday efficiency
Solution Approach 1:
The patent changes the material parameter of the electrode from conventional carbon/graphite to materials with high hydrogen overvoltage potential (lead, bismuth, zinc, titanium, molybdenum, or tungsten). This material substitution fundamentally alters the electrochemical properties, suppressing the hydrogen evolution reaction and improving Faraday efficiency while maintaining the electrode's functional performance.
Solution Approach 2:
The patent employs composite electrode structures combining materials with high hydrogen overvoltage potential (such as lead or bismuth) with conductive materials (graphite or carbon). This composite approach leverages the high hydrogen overvoltage potential of the first material to suppress unwanted reactions while utilizing the excellent electrical conductivity of carbon materials, achieving both high Faraday efficiency and good electrical performance.
2Quantity of substance
If the electrode active material is liquid and stored in tanks, then energy storage capacity increases, but the hydrogen evolution reaction at electrodes reduces charge ratio balance
Solution Approach 1:
The patent changes the electrochemical parameter of the electrode material by selecting substances with high hydrogen overvoltage potential. This parameter change directly addresses the charge ratio imbalance caused by hydrogen evolution, allowing the liquid electrolyte system to maintain stable charge ratios and enabling larger energy storage capacity without compromising compositional stability.
3Area of moving object
If porous electrode structure is used to maximize surface area, then electrochemical activity increases, but hydrogen evolution reaction is intensified
Solution Approach 1:
The patent changes the material composition parameter of the electrode to include substances with high hydrogen overvoltage potential. This material parameter change suppresses the hydrogen evolution reaction even in porous structures with large surface areas, allowing the electrode to maintain high electrochemical activity while minimizing harmful hydrogen formation.
Solution Approach 2:
The patent creates composite porous electrodes combining materials with high hydrogen overvoltage potential (lead, bismuth, etc.) with porous carbon materials. This composite structure maintains the beneficial porous morphology for high surface area and electrochemical activity while the high overvoltage potential material suppresses hydrogen evolution, resolving the contradiction between surface area and hydrogen formation.
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 increases electron transfer efficiency, reduces hydrogen production, and maintains electrolyte pH balance, allowing for longer battery operation without electrolyte exchange and improved energy storage efficiency.
Implementation Method 1
a first chamber (4) is separated from the second chamber (5) by means of a membrane (3)
Implementation Method 2
The liquid electrolyte therefore typically comprises a reduction-oxidation pair as electrode active material. The electrode active material is reduced or oxidized at the electrodes.
Implementation Method 3
a first planar surface of the cathode (30) and/or a second planar surface of the anode (16) have elevations (27) for enlarging the surface area and these elevations (27) are suitable for forming flow channels (26) for a first and/or second electrolyte
Implementation Method 4
The cathode (30) and/or the anode (16) comprise at least a first material (25) comprising lead, bismuth, zinc, titanium, molybdenum or tungsten... which have a lower overvoltage potential for hydrogen evolution
Data Source
AI summary
Various embodiments include an electrically rechargeable redox flow battery comprising: a first chamber; a second chamber; a membrane separating the first chamber from the second chamber; a cathode in the first chamber; and an anode in the second chamber. At least one of the cathode and the anode comprises a first planar surface including elevations enlarging the surface area. The elevations form flow channels for an electrolyte. The at least one of the cathode and the anode further comprises a material selected from the group consisting of: lead, bismuth, zinc, titanium, molybdenum, and tungsten.