Electrolytic Capacitor Electrolyte Gradient for Stable ESR
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Solution Overview
Problem
Existing electrolytic capacitors experience a significant increase in equivalent series resistance (ESR) over time, which is detrimental to their performance and longevity.
Innovation Solution
The electrolytic capacitor design includes a non-aqueous solvent-based electrolyte layer with varying concentrations of conductive particles on either side of a central plane, ensuring a balanced distribution that suppresses ESR increase by leveraging the stability of conductive particles and conductive polymers like polypyrrole, polythiophene, and polyaniline.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional electrolyte layer with uniform conductive particle distribution is used, then the manufacturing process is simple, but the ESR increases significantly over time
Solution Approach 1:
The electrolyte layer is designed with non-uniform conductive particle distribution, where the first portion (near anode) contains a different amount of conductive particles compared to the second portion (near cathode). This local variation in composition optimizes ESR stability over time by addressing different functional requirements at different locations within the electrolyte layer.
Solution Approach 2:
The electrolyte layer is divided into distinct portions (first portion near anode, second portion near cathode) with different conductive particle concentrations. This segmentation allows each region to perform its specific function optimally, preventing the time-dependent ESR increase that occurs in uniform distributions.
2Reliability
If conductive particles are added to reduce ESR, then the initial ESR decreases, but the ESR still increases over time due to conductive polymer degradation
Solution Approach 1:
Different portions of the electrolyte layer contain different concentrations of conductive particles, creating a gradient that compensates for conductive polymer degradation over time. The first portion near the anode has a different particle concentration than the second portion near the cathode, ensuring long-term ESR stability.
3Quantity of substance
If a solid electrolyte layer with high conductive polymer content is used, then the capacity increases, but the ESR increases due to heat generation from ripple current
Solution Approach 1:
The electrolyte layer combines conductive polymers with conductive particles in a non-aqueous solvent, creating a composite material that achieves both high capacity and low ESR. The conductive particles provide stable conductivity that is less susceptible to heat generation and degradation compared to conductive polymers alone.
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 configuration results in a low and stable ESR over an extended period, maintaining capacitor performance and reducing degradation.
Implementation Method 1
the electrolyte layer includes a non-aqueous solvent, conductive particles, and a conductive polymer
Implementation Method 2
a dielectric layer formed on a surface of the anode body
Data Source
AI summary
A disclosed electrolytic capacitor includes a capacitor element. The capacitor element includes an anode body, a dielectric layer formed on a surface of the anode body, a cathode body, and a electrolyte layer and a separator that are disposed between the dielectric layer and the cathode body. The electrolyte layer includes a non-aqueous solvent, conductive particles, and a conductive polymer. An amount of the conductive particles present in a first portion included in the electrolyte layer and located on the dielectric layer side is different from an amount of the conductive particles in a second portion included in the electrolyte layer and located on the cathode body side.