Asymmetric Electrode Tab Layout for Reliable Battery Cell Welding
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Solution Overview
Problem
Manufacturing battery cells with a large number of electrodes is challenging due to the difficulty in reliably welding a significant number of external tabs together, which affects the reliability and efficiency of the welding process.
Innovation Solution
Implementing asymmetric electrode tabs on cathode and anode electrodes, where external tabs are offset and welded separately, reducing the number of tabs that need to be welded simultaneously, and using pre-welding and main welding techniques to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large number of external tabs are welded together simultaneously, then the battery cell can accommodate more electrodes and achieve higher power density, but the welding reliability decreases due to the complexity and difficulty of the welding process
Solution Approach 1:
The patent divides the welding process into multiple separate welding operations. Instead of welding all external tabs simultaneously, the tabs are welded in groups or individually at different times and locations. This segmentation reduces the complexity of each welding operation, allowing for better control and higher reliability while still accommodating a large number of electrodes for high power density.
Solution Approach 2:
The patent employs asymmetric tab arrangements where tabs are positioned at different locations rather than symmetrically distributed. This asymmetry allows for optimized welding sequences and reduces the number of tabs that need to be welded simultaneously, thereby improving welding reliability while maintaining the ability to pack more electrodes for higher power density.
2Productivity
If multiple external tabs are welded together at the same time, then the assembly process can be completed faster, but the welding quality and reliability deteriorate due to process complexity
Solution Approach 1:
The welding process is segmented into multiple sequential steps rather than attempting to weld all tabs simultaneously. Each welding step involves fewer tabs, which improves welding quality and reliability. The segmented approach maintains productivity by organizing the welding operations in an efficient sequence that minimizes total assembly time while ensuring high-quality welds.
3Productivity
If the number of electrodes in the battery cell is increased, then the power density increases, but the difficulty and complexity of welding the external tabs increases significantly
Solution Approach 1:
The patent applies segmentation to manage the welding complexity that arises from increasing the number of electrodes. By dividing the welding process into multiple separate operations and welding tabs at different locations and times, the complexity of each individual welding task is reduced, making it feasible to accommodate more electrodes for higher power density without overwhelming welding process complexity.
Solution Approach 2:
Asymmetric tab positioning is used to optimize the welding process for high electrode counts. The asymmetric arrangement allows for strategic grouping and sequencing of welding operations, reducing the overall process complexity while enabling the battery cell to accommodate a larger number of electrodes for enhanced power density.
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 method increases the reliability of welds by reducing the complexity of simultaneous welding, allowing for more efficient assembly and higher power density in battery cells.
Implementation Method 1
At least one of: the first external tabs of the C cathode current collectors are welded together, and the second external tabs of the C cathode current collectors are welded together, and the first external tabs of the A anode current collectors are welded together, and the second external tabs of the A anode current collectors are welded together
Data Source
AI summary
A battery cell includes cathode electrodes including cathode electrode coatings arranged on cathode current collectors, and anode electrodes including anode electrode coatings arranged on anode current collectors. The cathode electrodes and the anode electrodes are arranged in a predetermined order in a stack. The cathode current collectors include first external tabs in a first asymmetric position and second external tabs in a second asymmetric position. The first external tabs and the second external tabs of the cathode electrodes are welded to a cathode lead tab. The anode current collectors include first external tabs in a first asymmetric position and second external tabs in a second asymmetric position. The first external tabs and the second external tabs of the anode electrodes are welded to an anode lead tab.