Capacitor Electrolyte OCC Control for Low Gas and Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a high demand for capacitors with increased volume efficiency and improved lifetime, while maintaining capacitance or miniaturization, and existing capacitors with high volume efficiency often have reduced lifetimes.
Innovation Solution
The use of sintered anodes with a sintered portion comprising merged metallic particles, preferably aluminum, and an electrolyte with an oxide creation capability (OCC) of at least 1.3 V/s, refractive index of 1.42 at 20°C, and specific composition electrolytes comprising boron compounds, reduces gas formation and leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If sintered anodes are used to increase volume efficiency, then volume efficiency is improved, but gas formation and leakage currents increase
Solution Approach 1:
The patent applies parameter changes by modifying the oxide layer properties through controlled formation processes. Specifically, the oxide layer is formed with controlled thickness (1-10 μm), porosity (30-70%), and composition by adjusting formation voltage, temperature, and electrolyte composition. This creates an oxide layer that maintains volume efficiency while reducing gas formation and leakage currents through optimized structural parameters.
Solution Approach 2:
The patent uses composite materials by combining the sintered anode structure with a specifically engineered oxide layer. The oxide layer acts as a composite material with controlled porosity and composition that covers the sintered anode surface, providing both volume efficiency benefits and reduced harmful effects through the composite structure of metal particles plus protective oxide coating.
2Quantity of substance
If high surface area anodes are used, then capacitance is increased, but leakage currents and gas formation increase
Solution Approach 1:
The patent applies parameter changes by controlling the oxide layer formation parameters including voltage (1-10 V), temperature (20-100°C), and time to achieve optimal oxide thickness and porosity. This controlled formation process creates an oxide layer that maintains high surface area for capacitance while minimizing leakage paths and gas generation sites through optimized structural parameters.
Solution Approach 2:
The patent applies local quality by creating a non-uniform oxide layer with specific porosity distribution (30-70%) and thickness variation (1-10 μm) across the anode surface. This localized optimization allows high surface area regions to maintain capacitance while controlled oxide regions reduce leakage currents and gas formation, addressing different functional requirements in different areas.
3Strength
If mild forming parameters are applied to sintered anodes, then structural integrity is maintained, but oxide layer defects are not sufficiently reduced
Solution Approach 1:
The patent applies parameter changes by using elevated formation temperatures (60-100°C) and optimized voltage ranges (3-10 V) that are more severe than conventional mild parameters. These enhanced parameters sufficiently reduce oxide layer defects and improve reliability while the controlled duration and electrolyte composition prevent excessive structural damage, achieving both structural integrity and high oxide quality.
Solution Approach 2:
The patent applies preliminary action by performing a controlled oxide formation process before final capacitor assembly. This preliminary oxide layer creation with optimized parameters pre-reduces defects and establishes a high-quality oxide structure that maintains structural integrity while ensuring low leakage and high reliability in the final product.
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 efficacy of the solution is demonstrated by reduced gas generation, lower leakage currents, and increased capacitor lifetime, particularly in capacitors with sintered anodes.
Implementation Method 1
the inventors found that an electrolyte with good oxide creation capability (OCC) is advantageous and can help to increase the lifetime of a capacitor
Implementation Method 2
the inventors found that it is advantageous if the electrolyte is capable of oxidizing said portions
Data Source
AI summary
An electrolyte for an electrolytic capacitor and a capacitor having said electrolyte are provided. The electrolyte has an oxide creation capability (OCC) value of at least 1.3 V/s or a refractive index of at least 1.42 at 20° C.