Electrode Assembly Weld Seam Layout for Low-ESR Supercapacitors
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Solution Overview
Problem
Existing ultracapacitors face challenges in achieving optimal thermal, electrical, and mechanical characteristics due to suboptimal weld seam geometries in the connection between current collectors and electrode assemblies, leading to high equivalent series resistance (ESR) and thermal heating during high power demand.
Innovation Solution
The method involves forming specific weld seam geometries, including transport and collector weld seams, oriented along radial and circumferential directions to improve current flow efficiency, reducing ESR and thermal heating by enhancing current collection and distribution within the electrode assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional weld seam geometries are used to connect current collectors to electrode assemblies, then manufacturing simplicity is maintained, but equivalent series resistance (ESR) increases and thermal characteristics deteriorate during high power demand
Solution Approach 1:
The weld seam is divided into multiple distinct geometric segments including a radially extending transport weld seam and a circumferentially extending collector weld seam. This segmentation allows each portion to perform its specific function optimally - the transport seam moves current radially while the collector seam distributes it circumferentially, reducing overall ESR without requiring complex multi-component assemblies
Solution Approach 2:
The weld seam geometry transitions from a simple linear or point connection to a two-dimensional planar pattern on the welding surface. By adding the circumferential collector weld seam component that extends in the tangential direction, the current distribution is optimized across the surface area, reducing resistance without increasing structural complexity
2Reliability
If weld seam geometries are optimized to reduce ESR, then electrical conductivity improves, but manufacturing precision requirements increase
Solution Approach 1:
Different portions of the weld seam are given different geometric qualities suited to their local function. The transport weld seam has a radial geometry optimized for current flow toward the center hub, while the collector weld seam has a circumferential geometry optimized for current distribution. This local optimization achieves superior electrical conductivity without requiring the entire weld seam to meet uniform high-precision standards
Solution Approach 2:
The welding implement moves along a predetermined path that first creates the transport weld seam and then the collector weld seam in sequence. This preliminary planning of the welding path allows the complex geometric pattern to be created through a systematic, repeatable process, reducing the actual manufacturing precision demands during execution
3Power
If high current is conducted through the electrode assembly during high power demand, then power output increases, but thermal heating increases due to resistance
Solution Approach 1:
The weld seam geometry is designed to convert the potentially harmful effect of current concentration into beneficial current distribution. The circumferential collector weld seam acts as a current redistribution network that takes concentrated current flows and distributes them across a larger area, converting what would be hot spots into evenly distributed current flow, thereby reducing thermal heating while maintaining high power output capability
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 proposed weld seam configurations effectively reduce ESR and thermal heating, improving the efficiency and longevity of ultracapacitors by enabling better current conduction and reducing heat generation during charging and discharging.
Implementation Method 1
moving the welding implement relative to the welding surface to weld each cell component to the electrode assembly by forming a plurality of weld seams on the welding surface
Data Source
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AI summary
In order to improve thermo-electrical properties of energy storage cells, the invention proposes a method for welding at least one cell component (26) to an electrode assembly (18) of an energy storage cell (10), preferably a supercapacitor, the method comprising arranging each cell component (26) and the electrode assembly (18) in contact with each other, wherein each cell component (26) has an exposed welding surface (30) that is accessible for welding by a welding implement; moving the welding implement relative to the welding surface (30) to weld each cell component (26) to the electrode assembly (18) by forming a plurality of weld seams on the welding surface (30), wherein at least two of the formed weld seams are chosen from a group of weld seam types consisting of a transport weld seam that has a main directional component along a radial direction of the electrode assembly (18); and a collector weld seam (39) that has a main directional component along a circumferential direction of the electrode assembly (18).