Solid Electrolytic Capacitor with PEDOT:PSS Composite
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytic capacitors with in situ polymerized polymers face issues such as high leakage current and failure at high voltages, and struggle to achieve high capacitance with stable electrical performance, especially at extreme conditions like high temperatures and dry atmospheres due to difficulties in impregnating polymer slurries into nano-scale pores.
Innovation Solution
A solid electrolytic capacitor design featuring a sintered porous anode body from a valve metal powder with a high specific charge, a dielectric formed by anodically oxidizing the anode in an electrolyte containing an ionic compound and oxidizing agent, and a conductive polymer solid electrolyte, which results in improved electrical properties including low anomalous charging current and leakage current, even under extreme conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If in situ polymerized polymers are used as solid electrolyte, then low ESR and non-burning failure mode are achieved, but high leakage current and failure at high voltages occur
Solution Approach 1:
The patent changes the chemical composition parameters of the solid electrolyte by using PEDOT:PSS dispersion with specific ratios (PEDOT:PSS weight ratio 1:0.8 to 1:2.0) and controlled water content (5-50 wt%), thereby achieving both low ESR and reduced leakage current while improving high voltage stability
Solution Approach 2:
The patent employs a composite solid electrolyte system combining PEDOT (conductive polymer) and PSS (polymer acid) in a dispersion medium, creating a composite material that balances electrical conductivity with structural stability to reduce leakage current and prevent high voltage failure
2Quantity of substance
If high specific charge metal powders with nano-scale size are used, then high capacitance is achieved, but difficulty in impregnating polymer slurries into pores occurs
Solution Approach 1:
The patent modifies the rheological parameters of the polymer slurry by adjusting viscosity and molecular weight of the dispersion medium, enabling effective impregnation into nano-scale pores while maintaining high capacitance
Solution Approach 2:
The patent uses a dispersion medium as an intermediary carrier that facilitates the penetration of PEDOT:PSS complex into the fine pores of sintered metal powder, solving the impregnation difficulty while achieving high capacitance
3Ease of manufacture
If conventional solid electrolyte structures are used, then manufacturing is simplified, but unstable electrical properties at high temperature and dry atmosphere occur
Solution Approach 1:
The patent uses a composite PEDOT:PSS dispersion system that maintains manufacturing simplicity while providing stable electrical properties at high temperatures and in dry atmospheres through the synergistic interaction of conductive polymer and polymer acid components
Solution Approach 2:
The patent optimizes the local composition of the solid electrolyte by controlling the distribution of PEDOT and PSS phases within the porous structure, creating regions with appropriate conductivity and stability characteristics for extreme condition operation
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 capacitor exhibits excellent electrical properties with low anomalous charging current, leakage current, and stable capacitance and resistance at high temperatures and in dry atmospheres, maintaining performance over extended periods.
Implementation Method 1
a dielectric that overlies the anode body
Implementation Method 2
formed by anodically oxidizing the anode in an electrolyte containing an ionic compound and oxidizing agent
Implementation Method 3
a solid electrolyte that overlies the dielectric that includes a conductive polymer
Implementation Method 4
a sintered porous anode body formed from a valve metal powder
Data Source
AI summary
A solid electrolytic capacitor comprising a capacitor element that contains a sintered porous anode body formed from a valve metal powder having a specific charge of about 50,000 μF*V/g or more, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric that includes a conductive polymer is provided. The capacitor exhibits an anomalous charging current of about 0.25 amps or less when charged at a constant voltage rate increase of 120 volts per second, determined at a temperature of 23° C. and voltage of 16 volts.