Conductive Polymer Dispersion Liquid ESR Reduction
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Solution Overview
Problem
Existing methods for producing conductive polymer dispersion liquids, such as those used in capacitors, face issues with high polyanion content reducing electrical conductivity, unfavorable side reactions during chemical oxidative polymerization, and difficulty in controlling doping rates, leading to poor electrical conductivity and stability.
Innovation Solution
A method involving the preparation of an emulsion by blending a conductive polymer precursor monomer with a polyanion and an aqueous solvent, followed by chemical oxidative polymerization with an oxidant, using a thin-film spinning high-speed mixer to reduce micelle particle size and enhance adsorption, thereby improving electrical conductivity and reducing Equivalent Series Resistance (ESR) in electrolytic capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical oxidative polymerization is performed with polyanions, then conductive polymer can be formed, but excessive polyanion content reduces electrical conductivity
Solution Approach 1:
The invention controls the molecular weight parameter of polyanions within a specific range (1,000 to 300,000) to optimize the balance between doping effectiveness and electrical conductivity. By selecting appropriate molecular weight parameters, the patent achieves sufficient doping while minimizing excessive polyanion content that would harm conductivity.
Solution Approach 2:
The patent creates localized doping regions where polyanions are concentrated at specific sites on the conductive polymer chains rather than uniformly distributed. This local quality approach allows effective doping in critical regions while maintaining lower overall polyanion content, thus preserving electrical conductivity.
2Reliability
If high molecular weight polyanions are used for doping, then doping effectiveness increases, but permeability into porous bodies decreases
Solution Approach 1:
The invention specifies a molecular weight range (1,000 to 300,000) for polyanions that balances two competing requirements: sufficient molecular weight for effective doping and low enough molecular weight for good permeability into porous capacitor bodies. This parameter optimization resolves the contradiction between doping effectiveness and permeability.
3Reliability
If polyanions are used for doping conductive polymer precursor monomer, then electrical conductivity improves, but Equivalent Series Resistance (ESR) increases due to excess polyanions
Solution Approach 1:
By controlling polyanion molecular weight within the specified range and managing the doping process parameters, the invention achieves adequate electrical conductivity while minimizing the harmful effect of excess polyanions on ESR. The parameter control prevents polyanion overload that would increase ESR.
Solution Approach 2:
The patent effectively extracts or removes excess polyanions from the system through controlled doping processes, retaining only the necessary amount for achieving good electrical conductivity. This extraction approach minimizes the harmful presence of excess polyanions that would increase ESR.
4Reliability
If micelle particle size is reduced for better dispersion, then electrical conductivity improves, but manufacturing complexity increases
Solution Approach 1:
The invention specifies a micelle particle size range (5 nm to 100 nm) that achieves good electrical conductivity through improved dispersion while avoiding excessively small sizes that would require complex manufacturing processes. This parameter selection balances performance with manufacturing feasibility.
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 results in a conductive polymer dispersion liquid with improved electrical conductivity and reduced ESR in electrolytic capacitors, as well as easier removal of unreacted materials and impurities, enhancing the long-term stability and performance of the capacitors.
Implementation Method 1
forming a dispersoid of a conductive polymer by chemical oxidative polymerization with addition of an oxidant to the emulsion
Implementation Method 2
preparing an emulsion of a polyanion adsorbed on a conductive polymer precursor monomer
Data Source
AI summary
A method for producing a conductive polymer dispersion liquid includes preparing an emulsion of a polyanion adsorbed on a conductive polymer precursor monomer by emulsifying a blended liquid obtained by blending the conductive polymer precursor monomer, the polyanion, and an aqueous solvent; and forming a dispersoid of a conductive polymer by chemical oxidative polymerization with addition of an oxidant to the emulsion. Furthermore, by using this conductive polymer dispersion liquid to provide an electrolytic capacitor, the ESR of the capacitor can be reduced.