Laser Welding Parallel Cell Tabs for Battery Interconnects
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Solution Overview
Problem
Ultrasonic welding methods for joining cell tabs in multi-cell electrochemical devices result in variations due to tool wear, increased tooling expenses, and limitations in device design and configuration, leading to inconsistent weld quality and reduced efficiency.
Innovation Solution
Laser-welding of cell tabs to an interconnecting member, where the tabs are bent and notched to lie in the same plane, allowing for consistent and efficient joining with reduced tool wear and improved design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic welding methods are used to join cell tabs, then welding can be achieved, but weld quality varies due to tool wear and tooling expenses increase
Solution Approach 1:
The patent replaces the mechanical ultrasonic welding system with a laser welding system. The laser welding process uses optical energy instead of mechanical contact, eliminating tool wear and associated expenses while maintaining consistent weld quality throughout the tooling lifecycle.
Solution Approach 2:
The patent changes the welding process parameters by transitioning from ultrasonic vibration-based welding to laser-based welding. This parameter change fundamentally alters the welding mechanism, eliminating the wear-related quality variations inherent in mechanical ultrasonic welding.
2Adaptability or versatility
If ultrasonic welding apparatus is used, then cell tabs can be joined, but device design and configuration are limited by the welding apparatus geometry
Solution Approach 1:
By replacing the mechanical ultrasonic welding apparatus with a laser welding system, the patent eliminates the geometric constraints imposed by physical welding tools. Laser welding allows for greater design flexibility as the laser beam can access and weld tabs in configurations that would be difficult or impossible for mechanical tools.
3Manufacturing precision
If laser-welding is used to join cell tabs, then weld repeatability and tool clearance are improved, but process implementation complexity increases
Solution Approach 1:
The substitution of mechanical ultrasonic welding with laser welding inherently improves weld repeatability by eliminating tool wear. While laser welding equipment is sophisticated, the process itself is more consistent and repeatable, and the patent demonstrates practical implementation in battery manufacturing.
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
Laser-welding achieves high repeatability, reduced mass and volume, and increased electrical current capacity, enabling more efficient and cost-effective battery cell configurations with improved tool clearance and robust welds.
Implementation Method 1
laser-welding of one or more cell tabs and interconnecting members in a multi-cell electrochemical device
Data Source
AI summary
Multiple cell tabs are effectively joined in a cost-effective and more consistent manner that can result in less mass and volume per interconnect. Cell tabs can be made of a material that is sufficiently thick enough to be able to carry several times the current of other tabs. The tabs are notched to engage an interconnecting member where the notching is performed in the same stage as making individual cell tab bends. Once the cell tabs are notched and bent, they are then positioned together such that the notched portions lie on the interconnecting member in a flat, side-by-side manner, all at the same height. The cell tabs are then held closely to the interconnect and laser-welded.