TMCCC Electrode Moisture Control to Preserve Cell Capacity
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Solution Overview
Problem
Existing electrochemical cell manufacturing processes face challenges in optimizing the water content of transition metal cyanide coordination compound (TMCCC) electrodes, as total dehydration degrades performance, while conventional methods require complex and costly dry room processes to remove trace water impurities.
Innovation Solution
Optimize the water content of TMCCC electrodes by maintaining a controlled residual moisture (RM) that includes lattice-bound water and minimizes non-coordinated water, allowing for partial dehydration or hydration to achieve a desired RM within a specific range, and performing drying processes on assembled cell stacks rather than individual components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If total dehydration is performed on TMCCC electrodes to remove all water, then trace water impurity is eliminated, but electrochemical capacity and performance are degraded due to phase transition
Solution Approach 1:
The patent changes the parameter of water content from complete removal (anhydrous) to controlled residual moisture (0.1-5%). This parameter optimization prevents the harmful phase transition while maintaining electrochemical capacity, resolving the contradiction between eliminating water impurity and preserving performance.
Solution Approach 2:
Instead of complete dehydration, the patent applies partial dehydration to achieve optimal residual moisture levels. This partial action removes sufficient water to prevent harmful effects while retaining enough water to maintain the cubic phase and electrochemical capacity.
2Object-affected harmful factors
If rigorous dry room processes are implemented to remove trace water, then water impurity is reduced, but manufacturing complexity and costs increase
Solution Approach 1:
The patent performs dehydration as a preliminary action during electrode fabrication before cell assembly. By removing water at this early stage and sealing the cell, subsequent manufacturing steps do not require complex dry room environments, significantly simplifying the overall manufacturing process.
Solution Approach 2:
The patent combines the dehydration step with the electrode fabrication process itself, rather than treating it as a separate post-processing step. This integration allows water removal to be accomplished using standard fabrication equipment without requiring additional dry room infrastructure.
3Object-affected harmful factors
If independent drying of cell materials is performed in dry rooms, then water content is controlled, but production time and resource costs increase
Solution Approach 1:
The patent performs water removal as a preliminary action during electrode fabrication, before cell assembly. This timing allows the dehydration to be integrated into the existing fabrication workflow without adding separate drying steps, thereby reducing total production time.
Solution Approach 2:
The patent merges the water removal step with the electrode fabrication process, combining two operations into one. This eliminates the need for separate drying cycles and reduces the cumulative time and resources required compared to independent drying of materials followed by assembly.
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
Improves electrochemical cell performance by balancing water content for optimal energy efficiency, cycle life, and reducing manufacturing complexity and costs by using less aggressive drying methods on assembled cell stacks.
Implementation Method 1
When this occurs, the MnHCF material undergoes a phase transition from a cubic phase to a rhombohedral phase
Implementation Method 2
Reference [2] further describes the use of a vacuum drying process in which the vacuum pressure is below 0.1 torr
Data Source
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AI summary
A system and method for optimizing electrochemical cells including electrodes employing coordination compounds by mediating water content within a desired water content profile that includes sufficient coordinated water and reduces non-coordinated water below a desired target. A process by which the performance of a cell containing one or more TMCCC materials may be improved may include providing the electrodes with an optimal amount of residual moisture (RM). Too high a RM, and enough non-coordinated, including mobile, water is present that cell performance may degrade. Too low a RM, and the TMCCC electrode performance is decreased. But by fine-tuning the RM of the electrode, an optimal balance of electrode and cell performance properties may be achieved.