Wet Electrolytic Capacitor Composite Coating ESR Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wet electrolytic capacitors face challenges with capacitance enhancement due to expensive coatings that can detach easily, leading to performance degradation and increased equivalence series resistance (ESR).
Innovation Solution
A wet electrolytic capacitor design featuring a composite coating with a noble metal layer and a conductive polymer layer over a metal substrate, which enhances electrical performance by minimizing electrochemical reactions and heat absorption, thereby stabilizing the capacitor's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive material coating is applied to the metal casing to enhance capacitance, then capacitance is improved, but the cost increases
Solution Approach 1:
The coating is divided into multiple distinct layers: a noble metal layer (first coating) applied directly to the metal casing, and a conductive polymer layer (second coating) applied over the noble metal layer. This segmentation allows each layer to perform its specific function - the noble metal layer provides stable adhesion and electrochemical inertness, while the conductive polymer layer provides the desired capacitance enhancement without detaching.
Solution Approach 2:
The invention uses a composite coating structure combining two different materials with complementary properties: a noble metal (such as ruthenium oxide) that is chemically stable and adheres well to the metal casing, and a conductive polymer that provides high capacitance. The combination leverages the advantages of both materials while mitigating their individual disadvantages.
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 improved electrical properties with increased capacitance and reduced ESR, maintaining performance even at high temperatures and over extended periods.
Implementation Method 1
the noble metal layer can further enhance the electrical performance of the capacitor by helping to minimize electrochemical reactions between components of the coating and the fluid electrolyte
Implementation Method 2
because the polymers are generally semi-crystalline or amorphous, they can dissipate and/or absorb the heat associated with the high voltage, which in turn inhibits fluid electrolyte phase transitions
Implementation Method 3
These tantalum slugs first undergo an electrochemical oxidation that forms an oxide layer coating acting as dielectric over the entire external and internal surfaces of the tantalum body
Data Source
AI summary
A wet electrolytic capacitor that contains a casing within which is positioned an anode formed from an anodically oxidized sintered porous body and a fluidic working electrolyte is provided. The casing contains a composite coating disposed on a surface of a metal substrate. The composite coating includes a noble metal layer that overlies the metal substrate and a conductive polymer layer that overlies the noble metal layer.