Conductive polymer dispersion and high-voltage solid-state capacitor conductive polymer emulsion

Abstract

The invention provides conductive polymer dispersion and high-voltage solid-state capacitor conductive polymer emulsion. The preparation method comprises the following steps: adding acrylate, acrylamide and an emulsifier into an aqueous solution of sodium polystyrenesulfonate, and by taking ammonium persulfate as an initiator, performing emulsion polymerization; adding an EDOT (Ethylenedioxy Thiophene) monomer into the polymerized emulsion, and by taking ferric sulfate as a catalyst, dripping sodium persulfate serving as an oxidizing agent so as to obtain a mixed solution; removing the residual unreacted organic monomer in the mixed solution and inorganic salt components in the liquid; and adding polyglycerol, a wetting agent and a conductive reinforcing agent into the solution, and homogenizing under high voltage. The invention further comprises application of the dispersion obtained by the method to preparation of a solid electrolytic capacitor. Aqueous dispersion of a conductive polymer is synthesized, the impurities are purified and removed, the dispersion is impregnated and dried to serve as electrolyte of the capacitor, no impurity harmful to an oxidation film exists in the impregnation solution, capacitor leakage is reduced, and the withstand voltage of the product is increased.

Description

technical field [0001] The invention belongs to the technical field of preparation of solid electrolytic capacitors, in particular to a high-solid conductive polymer dispersion in solid electrolytic capacitors. Background technique [0002] Conductive polymer solid capacitors have excellent high-frequency and low-resistance characteristics, and are widely used in various applications. With the reduction of costs, there is a tendency to gradually replace the original liquid electrolytic capacitors. However, under its superior impedance characteristics and life characteristics, solid capacitors also have obvious disadvantages compared with traditional liquid electrolytic capacitors. Since solid capacitors are prepared by in-situ polymerization of monomers and oxidants in capacitor core packs, strong acid p-toluenesulfonate is used Ferric acid, as an oxidant and dopant, has a destructive effect on the oxide film of the anode foil, resulting in a large leakage current. Usually t...

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Problems solved by technology

Conventional emulsions are often composed of hydrophobic polymers wrapped by hydrophilic groups to form granular emulsions. The hydrophilic groups are wrapped outside the emulsion to stabilize the emulsion and do not stretch in a free state in water. Therefore the viscosity is lower

[0004] However, the conductive polymer dispersion generally has the disadvantages of low solid content and high viscosity; it is introduced into the capacitor core package by impregnation and drying, which makes it difficult to increase the filling rate of the conductive polymer in the core package, making the characteristics of capacity extraction and ESR Poor, especially low temperature performance is difficult to meet the standard

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