Multi-Separator Electrochemical Cells for Low-Evaporation Assembly
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Solution Overview
Problem
Conventional electrochemical cell production processes face significant costs due to electrolyte solvent evaporation, which can be costly to replace, and this evaporation hinders the efficient production of semi-solid electrodes.
Innovation Solution
The production method involves coupling separators to anode and cathode materials during the electrochemical cell formation, using semi-solid electrodes with integrated liquid electrolyte, and employing multiple separators to minimize electrolyte solvent evaporation, thereby reducing tortuosity and enhancing electrolyte transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional production processes are used with solid electrodes and electrolyte addition, then electrolyte can be easily added to the container, but electrolyte solvent evaporates significantly during the production process
Solution Approach 1:
The electrolyte is incorporated into the electrode structure during the electrode formation process itself, rather than being added separately afterward. This preliminary integration prevents subsequent evaporation losses during production handling and transport.
Solution Approach 2:
The electrolyte is merged with the active material and conductive material to form a unified semi-solid electrode structure. This combination eliminates the need for separate electrolyte addition and prevents evaporation by integrating the electrolyte within the electrode matrix.
2Quantity of substance
If semi-solid electrodes with liquid electrolyte are used, then electrolyte transport is improved, but electrolyte solvent evaporates during production
Solution Approach 1:
A separator is applied as a thin film or coating over the semi-solid electrode, creating a protective barrier that prevents electrolyte solvent evaporation while maintaining the liquid electrolyte's ability to transport ions within the electrode structure.
Solution Approach 2:
The separator acts as an intermediary layer between the liquid electrolyte and the external environment, allowing ion transport through the separator while blocking the evaporation of electrolyte solvent during production and handling.
3Reliability
If multiple separators are used to prevent evaporation, then electrolyte integrity is maintained, but device complexity increases
Solution Approach 1:
The protective function is segmented into multiple thin separator layers, each contributing to overall evaporation prevention. This segmentation allows the system to achieve high reliability through layered protection while keeping individual components simple and manageable.
4Loss of substance
If separators with low porosity are used to prevent evaporation, then solvent loss is reduced, but ion diffusion may be hindered
Solution Approach 1:
The separator is designed with spatially varying properties: regions with lower porosity near the electrode surface to prevent evaporation, and regions with higher porosity to facilitate ion diffusion. This local quality variation allows simultaneous optimization of both evaporation prevention and ion transport.
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 approach significantly reduces electrolyte solvent evaporation, maintains electrolyte integrity, and enhances the charge capacity and energy density of the electrochemical cells by minimizing salt buildup and improving ion diffusion, while also providing overcharge protection and early detection of potential short circuits.
Implementation Method 1
less than about 10% by volume of the liquid electrolyte evaporates during the forming of the electrochemical cell
Implementation Method 2
improving ion diffusion
Implementation Method 3
the first separator and/or the second separator can be composed of a material with a porosity of less than about 1%
Data Source
AI summary
Embodiments described herein relate to electrochemical cells with multiple separators, and methods of producing the same. A method of producing an electrochemical cell can include disposing an anode material onto an anode current collector, disposing a first separator on the anode material, disposing a cathode material onto a cathode current collector, disposing a second separator onto the cathode material, and disposing the first separator on the second separator to form the electrochemical cell. The anode material and/or the cathode material can be a semi-solid electrode material including an active material, a conductive material, and a volume of liquid electrolyte. In some embodiments, less than about 10% by volume of the liquid electrolyte evaporates during the forming of the electrochemical cell. In some embodiments, the method can further include wetting the first separator and/or the second separator with an electrolyte solution prior to coupling the first separator to the second separator.