Microelectrode Capsule with Porous Conducting Network for Water Electrolysis
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Solution Overview
Problem
Existing Ni(OH)2 electrodes in water electrolysis suffer from low active material utilization, high thermal mass, limited current densities, and batch operation mode due to their design, which restricts continuous operation and efficiency in hydrogen and oxygen production.
Innovation Solution
Development of a microelectrode capsule with a conducting network core of fiber-like structures exhibiting open hierarchical porosity, allowing for the circulation of pellets within the electrochemical cell and reducing mechanical damage and Ohmic losses, while maintaining structural integrity and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional Ni(OH)2 electrodes with conductive substrate are used, then electrical conductivity is maintained, but thermal mass is high and material utilization is low
Solution Approach 1:
The electrode is segmented into discrete micropellets (0.5-5 mm diameter) that can circulate independently through the electrochemical cell. Each pellet contains conductive material distributed throughout its structure, eliminating the need for a large continuous conductive substrate and thereby reducing thermal mass while maintaining electrical conductivity through the distributed conductive network.
Solution Approach 2:
The micropellets are designed with porous structures that allow electrolyte penetration throughout the interior. This porosity enables efficient ion transport and electrochemical reactions throughout the bulk material, improving material utilization while the reduced size and elimination of thick conductive substrates decrease thermal mass.
2Quantity of substance
If thick active layer is deposited on current collector, then material loading is increased, but adhesion is poor and material utilization is very low
Solution Approach 1:
Instead of depositing a thick uniform layer that suffers from adhesion and utilization problems, the conductive material is distributed locally throughout the porous structure of each micropellet. This ensures that all material is electrochemically accessible and actively participating in reactions, achieving high material utilization while maintaining adequate loading.
Solution Approach 2:
The active material is transitioned from a two-dimensional surface coating on a current collector to a three-dimensional distributed structure within porous micropellets. This dimensional change allows electrolyte access to all material throughout the pellet interior, dramatically improving utilization while the compact pellet structure maintains high loading density.
3Stability of the object's composition
If electrodes are fixed to current collector, then structural stability is maintained, but continuous operation is prohibited and batch mode is required
Solution Approach 1:
The electrode system transitions from a static fixed configuration to a dynamic circulating system. Micropellets are held together by mechanical means (screen, filter, or mesh) that allow continuous movement and circulation through the electrochemical cell, enabling continuous operation while maintaining structural integrity through the holding mechanism.
Solution Approach 2:
The micropellets are extracted from their traditional fixed position on current collectors and placed into a circulating flow system. They are retained only by mechanical holding structures that permit continuous movement, separating the electrochemical function from the structural support function and enabling continuous operation.
4Reliability
If nickel foam current collector is used, then electrical conductivity is provided, but it accounts for most of the weight and cost
Solution Approach 1:
The micropellets use composite structures combining conductive materials (such as carbon or metal particles) with porous matrices. This distributes the conductivity function throughout the pellet structure rather than relying on a heavy nickel foam substrate, reducing weight while maintaining adequate electrical conductivity for electrochemical reactions.
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 microelectrode design enables continuous operation, enhances material utilization, and increases current densities, leading to improved efficiency and scalability in hydrogen and oxygen production with reduced thermal mass and mechanical stress.
Implementation Method 1
the capsule having a porosity enabling flow of liquid and gases therethrough
Implementation Method 2
reducing thermal mass and mechanical stress
Implementation Method 3
Water electrolysis converts electricity into chemical energy in the form of hydrogen gas (H2)
Implementation Method 4
NiOOH+H2O+e−Ni(OH)2+OH−E0=1.42VRHE
Data Source
AI summary
The invention disclosed herein generally contemplates novel microelectrodes and methods of preparing same.