Hybrid Electrolytic Capacitor with Conductive Polymer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid electrolytic capacitors exhibit poor recovery action at anodic oxide film failure, leading to increased leakage current and potential short circuits, while hybrid electrolytic capacitors face challenges in productivity and efficiency due to the formation of conductive polymer particles that do not improve charge movement between electrode foils.
Innovation Solution
A hybrid electrolytic capacitor design with a conductive polymer layer formed from fine particles of polythiophene or its derivatives, where the particles are dispersed in a solvent and impregnated into the capacitor element, optimizing the amount and size of particles to minimize loss and enhance electric characteristics, with an air-tight separator and specific particle distribution to improve charge movement and reduce leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If solid electrolytic material such as conductive polymer is used, then ESR is reduced and size is minimized, but recovery action at anodic oxide film failure becomes poor and leakage current increases
Solution Approach 1:
The patent combines liquid electrolyte and solid electrolytic material (conductive polymer) in a hybrid configuration. The liquid electrolyte provides recovery action at dielectric failure, while the solid conductive polymer maintains low ESR. This merging of two different electrolyte types resolves the contradiction between low energy loss and high reliability.
Solution Approach 2:
The capacitor employs a composite electrolyte system consisting of both liquid electrolyte and solid conductive polymer materials. This composite approach allows the device to simultaneously exhibit the beneficial properties of both material types: the self-healing capability of liquid electrolyte and the low resistance of solid polymer.
2Reliability
If conductive polymer layer is formed to improve electric characteristics, then leakage current is reduced, but productivity decreases due to particle loss
Solution Approach 1:
The patent optimizes critical parameters including particle size (1-10 μm), particle concentration (1-10 wt%), and air-tightness (0.5-2.0 s/100ml) to achieve the desired balance between leakage current reduction and manufacturing efficiency. By carefully controlling these parameters, the invention minimizes particle loss while ensuring adequate charge movement.
Solution Approach 2:
The separator is designed with specific porosity and air-tightness characteristics to allow efficient particle distribution while preventing excessive particle loss. The porous structure enables the conductive polymer particles to be properly distributed throughout the capacitor element without being retained or lost during manufacturing.
3Loss of energy
If fine particles of conductive polymer are used to enhance charge movement, then ESR is reduced, but particle loss increases and manufacturing becomes more difficult
Solution Approach 1:
The patent specifies an optimal particle size range of 1-10 μm that balances charge movement capability with manufacturing ease. Particles that are too fine would be difficult to handle and prone to loss, while larger particles would not provide sufficient ESR reduction. This parameter optimization resolves the contradiction between energy efficiency and manufacturability.
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
The design results in capacitors with smaller size, higher capacity, lower equivalent series resistance (ESR), reduced leakage current, and improved dielectric strength, while maintaining productivity and reliability, suitable for applications in audio-video and automotive electronics.
Implementation Method 1
the particles are dispersed in a solvent and impregnated into the capacitor element
Implementation Method 2
impregnated into the capacitor element
Implementation Method 3
anodic oxide film working as dielectric
Implementation Method 4
dielectric layer of the anodic oxide film is formed
Implementation Method 5
conductive polymer layer formed of particles or aggregate of the conductive polymer... enhance charge movement
Implementation Method 6
An air-tightness of the separator falls within the range from 0.5 s/100 ml to 2.0 s/100 ml
Data Source
AI summary
An electrolytic capacitor includes a capacitor element and an electrolyte solution impregnated in the capacitor element. The capacitor element includes an anode foil, cathode foil, separator, and a solid electrolytic layer. The anode foil has a dielectric layer on its surface, and the cathode foil confronts the anode foil. The separator is interposed between the anode foil and the cathode foil. The solid electrolytic layer is formed on the surfaces of the anode foil, cathode foil, and separator as an aggregate of fine particles of conductive polymer. The separator has an air-tightness not greater than 2.0 s/100 ml. Sizes of the fine particles measure not greater than 100 nm in diameter, and an amount of the fine particles contained falls within a range from 0.3 mg/cm2 to 1.2 mg/cm2, inclusive, as converted to weight per unit area of the anode foil.