Hybrid Capacitor Crosslinked Polymer Separator Design
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Solution Overview
Problem
Existing hybrid capacitors face limitations in size and design due to challenges in impregnating conductive polymers within the winding structure, leading to high Equivalent Series Resistance (ESR) and restricted capacitance, particularly in axial configurations, where the bottom tab is dipped in polymer, causing issues with voltage application and delamination of conductive polymer layers.
Innovation Solution
The method involves pre-treating anodes, cathodes, and separators with conductive polymer before forming the capacitor, allowing for cross-linking of conductive polymer layers within the structure, which enhances polymer distribution and adhesion, enabling the use of a conductive porous separator to facilitate liquid electrolyte flow and improve intermolecular bonding between solid and liquid electrolytes, thus allowing for larger and more versatile capacitor designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive polymer is impregnated into the winding structure after assembly, then the capacitor achieves low ESR, but the manufacturing process becomes complex and limited in size
Solution Approach 1:
The conductive polymer is applied to the separator and electrodes before the winding assembly is formed. This preliminary application allows the polymer to be uniformly distributed throughout the structure without requiring complex post-assembly impregnation processes, thereby maintaining low ESR while simplifying manufacturing
Solution Approach 2:
The separator is designed with porous structure that allows conductive polymer to be incorporated into its matrix. This porous structure enables the polymer to be distributed throughout the separator during the winding process itself, achieving low ESR through a simplified manufacturing approach
2Quantity of substance
If the capacitor size is increased, then higher capacitance is achieved, but the conductive polymer distribution becomes insufficient leading to higher ESR
Solution Approach 1:
The conductive polymer is specifically applied to the separator and electrode surfaces where it is needed for optimal performance. This localized application ensures that even in large-capacitance devices, the polymer is properly distributed at critical interfaces, maintaining low ESR while achieving high capacitance
Solution Approach 2:
The method changes the timing parameter of polymer application from post-assembly to pre-assembly. This parameter change allows the polymer to be distributed throughout the entire winding structure including interstitial spaces, ensuring adequate polymer presence in large capacitors to maintain low ESR
3Ease of manufacture
If conductive polymer is applied to axial capacitor bottom tab, then the capacitor can be formed, but voltage application becomes problematic and delamination occurs
Solution Approach 1:
The conductive polymer is extracted from the bottom tab area and concentrated on the separator and electrode surfaces instead. This extraction prevents the polymer from being applied to the bottom tab where it causes delamination, while still achieving the desired low ESR performance through proper polymer distribution on the separator and electrodes
Solution Approach 2:
The separator acts as an intermediary that receives and distributes the conductive polymer uniformly throughout the winding structure. By applying polymer to the separator rather than directly to the bottom tab, the separator mediates the distribution process, preventing delamination while ensuring adequate polymer presence for low ESR
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 approach results in capacitors with improved low ESR and high capacitance, enabling larger sizes and various designs, including axial configurations, with enhanced durability and electrical performance by ensuring complete conductive polymer coverage and stable intermolecular bonding.
Implementation Method 1
at least one of the conductive polymer layers is cross-linked within the layer, to an adjacent surface or to an adjacent conductive polymer layer
Implementation Method 2
the conductive polymer migrates, or diffuses, into the interstitial spaces
Implementation Method 3
use of a conductive porous separator to facilitate liquid electrolyte flow
Implementation Method 4
conductive polymers have a high conductivity, up to 600 S/cm, and therefore capacitors utilizing conductive polymeric cathodes have a much lower ESR
Data Source
AI summary
An improved capacitor is described wherein the capacitor comprises a working element. The working element comprises a first dielectric and an anode conductive polymer layer on the first dielectric. The working element also comprises a cathode and a separator between the anode conductive polymer layer and the cathode wherein the separator comprises a separator conductive polymer layer wherein at least one of the anode conductive polymer layer or the separator conductive polymer layer is crosslinked. The working element also comprises a liquid electrolyte.