Solid Electrolytic Capacitor Inert Gas Sealing High Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid electrolytic capacitors face instability at high temperatures due to the tendency of their electrolytes to transform from a doped to an undoped state, leading to performance issues in high-temperature environments.
Innovation Solution
A capacitor assembly is developed with an anodically oxidized, sintered porous anode and a solid electrolyte formed from a dispersion of conductive polymer particles, enclosed in a housing with an inert gas atmosphere to prevent oxygen and moisture exposure, enhancing thermal stability and volumetric efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid electrolyte is used in a conventional solid electrolytic capacitor, then volumetric efficiency and reliability are improved, but stability deteriorates at high temperatures due to transformation between doped and un-doped states
Solution Approach 1:
The capacitor is hermetically sealed in a housing filled with inert gas (nitrogen or argon) to create an inert atmosphere that prevents oxygen and moisture from reaching the solid electrolyte. This inert environment stabilizes the electrolyte by preventing unwanted chemical reactions and transformations between doped and un-doped states, thereby resolving the stability issue at high temperatures while maintaining the reliability benefits of solid electrolytes
2Stability of the object's composition
If the capacitor is hermetically sealed in an inert gas atmosphere, then electrolyte stability is improved at high temperatures, but device complexity increases
Solution Approach 1:
The harmful elements (oxygen and moisture) are extracted from the capacitor's internal environment by replacing air with inert gas and hermetically sealing the housing. This removes the destabilizing factors while maintaining a simple overall structure, thereby achieving electrolyte stability without significantly increasing device complexity
3Volume of moving object
If conductive polymer particles are used to form the solid electrolyte, then volumetric efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The conductive polymer particles are applied as a dispersion that self-assembles and forms a uniform solid electrolyte layer on the anode through natural deposition and drying processes. This self-organizing behavior reduces the need for precise manufacturing control while achieving high volumetric efficiency, as the particles automatically arrange themselves without requiring complex manufacturing interventions
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 solution provides improved stability and performance in high-temperature and high-voltage environments, maintaining low equivalent series resistance and leakage current, while achieving high energy density and volumetric efficiency.
Implementation Method 1
an anode formed from an anodically oxidized, sintered porous body
Implementation Method 2
sintered porous body
Implementation Method 3
The solid electrolyte is formed from a dispersion of conductive polymer particles
Implementation Method 4
hermetically sealing the capacitor element within the housing in the presence of a gaseous atmosphere that contains an inert gas
Data Source
AI summary
A capacitor assembly for use in high voltage and high temperature environments is provided. More particularly, the capacitor assembly includes a solid electrolytic capacitor element containing an anode body, a dielectric overlying the anode, and a solid electrolyte overlying the dielectric. To help facilitate the use of the capacitor assembly in high voltage applications, it is generally desired that the solid electrolyte is formed from a dispersion of preformed conductive polymer particles. In this manner, the electrolyte may remain generally free of high energy radicals (e.g., Fe2+ or Fe3+ ions) that can lead to dielectric degradation, particularly at relatively high voltages (e.g., above about 60 volts). Furthermore, to help protect the stability of the solid electrolyte at high temperatures, the capacitor element is enclosed and hermetically sealed within a housing in the presence of a gaseous atmosphere that contains an inert gas.