Electrolytic Capacitor Low-Volatile Solvent High-Temperature Reliability
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Solution Overview
Problem
Conventional hybrid-type electrolytic capacitors face issues with solvent volatility at high temperatures, leading to loss of self-repairing functionality in dielectric oxide films, resulting in increased leakage current and potential short circuits, especially when used beyond their guaranteed lifetime in harsh environments.
Innovation Solution
The use of a low-volatile polyalkylene glycol or its derivatives as a solvent in the electrolyte solution, which maintains its effectiveness even at high temperatures, ensuring the dielectric oxide film can be continuously repaired and reducing the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional electrolyte solution with volatile solvent is used in a hybrid-type electrolytic capacitor, then the capacitor achieves low ESR and good self-repairing function initially, but the solvent evaporates at high temperatures over time, causing loss of self-repairing capability, increased leakage current, and potential short circuits
Solution Approach 1:
The patent changes the physical and chemical parameters of the electrolyte solution by selecting a solvent with significantly lower volatility (lower vapor pressure and higher boiling point). This parameter change ensures that the solvent does not evaporate at high temperatures, maintaining the electrolyte solution's volume, composition, and self-repairing function throughout the capacitor's operational lifetime, thus resolving the contradiction between initial performance and long-term reliability.
2Duration of action of stationary object
If the capacitor is used beyond its guaranteed lifetime in harsh high-temperature environments, then the volatile solvent evaporates completely, but the capacitor structure remains intact, leading to open circuit rather than short circuit in liquid-type capacitors
Solution Approach 1:
The patent applies beforehand cushioning by selecting a non-volatile or low-volatility solvent that prevents the harmful effect (solvent loss) from occurring in the first place. This proactive measure ensures that even when used beyond the guaranteed lifetime in high-temperature environments, the electrolyte solution maintains its volume and self-repairing capability, preventing both open circuits (as in liquid-type capacitors) and short circuits (as in solid electrolytic capacitors), thus extending reliable service life.
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 solution provides a hybrid-type electrolytic capacitor with improved reliability by maintaining the self-repairing function of the dielectric oxide film, suppressing leakage current and ensuring excellent short-circuit resistance, even when used beyond the guaranteed lifetime at high temperatures.
Implementation Method 1
a hybrid-type electrolytic capacitor using an electrolyte solution, as material for an electrolyte, that is excellent in repairing a defective part in an anodic oxide film that is a dielectric body
Implementation Method 2
The use of a low-volatile polyalkylene glycol or its derivatives as a solvent in the electrolyte solution, which maintains its effectiveness even at high temperatures
Data Source
AI summary
An electrolytic capacitor includes a capacitor element. The capacitor element includes an anode including a dielectric layer thereon and a cathode member including a conductive polymer and in contact with the dielectric layer. The capacitor element is impregnated with a liquid containing at least one of polyalkylene glycol and derivatives of polyalkylene glycol. The liquid further contains an oxidation inhibitor.