Electrochemical Cell Radial Wick Oxygen Starvation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrochemical gas detectors face issues with oxygen starvation at the counter electrode, leading to reduced electrochemical efficiency and erroneous gas concentration measurements due to factors like orientation, hydration levels, and high target gas concentrations, which are exacerbated by the axial reservoir design causing high internal resistance and limited design flexibility.
Innovation Solution
The electrochemical cell incorporates a gas cavity adjacent to the counter electrode to provide a sustained source of oxygen, and a reservoir design that surrounds the wick rather than extending axially, minimizing electrode distance and reducing internal resistance, while a secondary wick ensures effective electrolyte transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an axial reservoir design is used to contain electrolyte, then the cell structure is simplified, but oxygen starvation occurs at the counter electrode leading to reduced electrochemical efficiency
Solution Approach 1:
The patent transitions from an axial reservoir design to a radial reservoir design where the reservoir surrounds the wick in a radial direction rather than extending axially. This dimensional change allows the counter electrode to remain exposed to oxygen at the top surface while the reservoir provides electrolyte containment, eliminating oxygen starvation without significantly increasing structural complexity.
2Quantity of substance
If the reservoir extends axially between electrodes, then electrolyte containment is achieved, but internal resistance increases due to larger electrode distance
Solution Approach 1:
The reservoir is repositioned from an axial location between electrodes to a radial location surrounding the wick. This allows electrolyte containment to be achieved through radial extension rather than axial extension, maintaining minimal axial distance between electrodes and thus keeping internal resistance low while still providing adequate electrolyte volume.
3Quantity of substance
If the cell height is increased to accommodate axial reservoir, then electrolyte volume is sufficient, but design flexibility and utility are reduced
Solution Approach 1:
The reservoir design transitions from axial extension (increasing cell height) to radial extension (increasing cell diameter). This allows sufficient electrolyte volume to be achieved without increasing cell height, thereby maintaining design flexibility and utility for various mounting configurations and applications.
4Device complexity
If orientation-dependent performance is accepted, then cell structure is simpler, but measurement accuracy varies with orientation and humidity
Solution Approach 1:
The radial reservoir design creates a symmetric structure where the counter electrode remains exposed to oxygen regardless of cell orientation. This geometric symmetry eliminates orientation-dependent performance variations, ensuring consistent measurement accuracy in any mounting position while maintaining relatively simple cell structure.
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 prevents oxygen starvation, maintains performance across various orientations and humidity conditions, and reduces the overall height of the cell, enhancing its utility and accuracy in detecting oxidizable and reducible gases.
Implementation Method 1
The wick 17 acts to hold and supply electrolyte to the sensing electrode 12
Implementation Method 2
The gas passes through the gas permeable membrane 18 of the sensing electrode 12
Implementation Method 3
The gas contacts the catalyst 12. A reaction occurs at the interface of the catalyst 12 and the acid electrolyte 16
Implementation Method 4
The positive ions travel through the electrolyte 16 to the counter electrode 14
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An electrochemical cell (10) for detecting a gas from the surrounding environment. The cell has a wick (17) extending between the sensing electrode (12) and the counter electrode (14) in an axial direction and a reservoir (119 surrounding the wick. The cell also comprises an electrolyte and a sensing electrode (12) which is in fluid communication with the electrolyte and the gas to be detected, when present. The cell further comprises a counter electrode (14) in fluid communication with said electrolyte.