Electrode Lead Wire Stitching for EDLC Contact Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing connecting structures between electrodes and lead wires in electric double layer capacitors face issues with high contact resistance and unreliable connections due to dielectric oxide layers and sparks during welding, leading to capacitance deterioration and short circuits.
Innovation Solution
A connecting structure where a polarized electrode layer is removed from the region where the lead wire is joined, and the lead wire is stitched and compressed onto a current collector plate, with a controlled contact area and pinhole diameter, to minimize resistance and ensure reliable contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If supersonic welding is used to join lead wire to electrode, then low resistance is achieved, but junction force is insufficient due to dielectric oxide layer
Solution Approach 1:
The patent removes the polarized electrode layer (activated carbon coating) from the specific region where the lead wire will be joined to the current collector plate. This extraction of the problematic dielectric layer from the connection zone enables both low contact resistance through direct metal-to-metal contact and sufficient junction force through mechanical interlocking, resolving the contradiction between electrical conductivity and mechanical strength.
Solution Approach 2:
The patent applies different properties to different regions of the electrode: the polarized electrode layer is maintained in the active capacitance regions but removed from the lead wire connection region. This local differentiation allows the connection zone to have optimal electrical and mechanical properties while preserving the energy storage function in other areas, thus achieving both low resistance and high junction force.
2Reliability
If supersonic welding is used to join lead wire to electrode, then low resistance is achieved, but impurities adhere to junction due to sparks
Solution Approach 1:
The patent replaces the supersonic welding process (which generates harmful sparks and impurities) with a mechanical stitching process using a sewing needle. This mechanical joining method achieves low contact resistance through direct metal-to-metal contact without generating sparks or adhesion impurities, thus eliminating the harmful side effects while maintaining the beneficial low resistance characteristic.
3Strength
If caulking is used to join lead wire to electrode, then sufficient junction force is achieved, but contact resistance becomes high
Solution Approach 1:
By removing the polarized electrode layer from the connection region, the patent eliminates the dielectric barrier that prevents good electrical contact. This allows the mechanical stitching process to achieve both low contact resistance through direct metal contact and sufficient junction force through the physical interlocking of the stitched structure, simultaneously resolving both electrical and mechanical requirements.
4Reliability
If compression is used to join lead wire to electrode, then low contact resistance is achieved, but junction force becomes insufficient
Solution Approach 1:
The patent merges two joining mechanisms: mechanical stitching (providing junction force through physical interlocking) and compression (providing low contact resistance through intimate metal contact). The stitched structure holds the lead wire in close contact with the current collector plate, combining the advantages of both methods to achieve simultaneously high junction force and low contact resistance.
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 reduces contact resistance and enhances connection reliability, maintaining capacitance and preventing short circuits, as demonstrated by experimental results showing stable capacitance and low initial resistance values.
Implementation Method 1
the lead wire is joined to the current collector plate by means of stitching
Implementation Method 2
then compressed thereto
Implementation Method 3
a region of the electrode, to which the lead wire is to be joined, is free from the polarized electrode layer
Data Source
AI summary
A connecting structure of a lead wire is electrically connected to an electrode in which a polarized electrode layer is formed on a surface of a current collector plate. A region of the electrode, to which the lead wire is to be joined, is free from the polarized electrode layer. The lead wire is joined to the current collector plate by means of stitching and then compressed thereto. This connecting structure may keep a capacitance of a capacitor and improve contact reliability. An electric double layer capacitor having the structure and a method for manufacturing the capacitor are also provided.