Battery Tab Assembly for Dense Stacking and Stronger Welds
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Solution Overview
Problem
The existing process of welding cell tab terminals in battery systems, particularly for prismatic or pouch-type cells, is inefficient due to air gaps and mismatching caused by accumulated tolerances, leading to reduced weld integrity and increased packaging size.
Innovation Solution
Pre-bend the cell tab terminals of adjacent cells in opposite directions before stacking, ensuring face-sharing contact and rolling them over a cell tab support to increase surface contact and reduce gaps, allowing for concurrent one-directional rolling and reduced manufacturing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cell tab terminals are trimmed, bent, and modified after stacking to create sufficient surface contact for welding, then weld integrity is improved, but manufacturing complexity and time increase due to requiring a two-step, bi-directional machine tab-rolling process
Solution Approach 1:
The cell tab terminals are pre-bent in opposite directions before stacking the cells. This preliminary action ensures that when cells are stacked, the tab terminals are already positioned to make contact with adjacent cell tabs, eliminating the need for complex post-stack adjustments and enabling a simpler single-step rolling process during welding.
2Reliability
If cell tab terminals are bent in opposite directions to make contact with adjacent cells, then weld contact area is improved, but packaging size increases due to reduced stacking density
Solution Approach 1:
The tab terminals are pre-bent before stacking to achieve optimal contact positioning. This allows the cells to be stacked closer together without compromising weld integrity, as the pre-bent tabs are designed to make contact at the precise location needed for welding, thereby maintaining compact battery packaging.
3Manufacturing precision
If a two-step, bi-directional machine tab-rolling process is used to bend tab terminals, then sufficient surface contact for welding is achieved, but manufacturing time and expense increase
Solution Approach 1:
The tab terminals are pre-bent in opposite directions before cell stacking. This preliminary configuration allows all tab terminals to be rolled in a single direction during the welding process, reducing the manufacturing process from two consecutive steps to one efficient step, thereby improving productivity while maintaining precision.
4Ease of manufacture
If cell tab terminals are not pre-bent and are instead rolled after stacking, then manufacturing process is simpler, but air gaps and mismatching occur between tab terminals reducing weld integrity
Solution Approach 1:
The tab terminals are pre-bent in opposite directions before stacking to anticipate and compensate for positioning variations. This preliminary action ensures that when cells are stacked, the tab terminals are already aligned for optimal contact, maintaining weld integrity while keeping the manufacturing process simple and efficient.
Data Source
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AI summary
Systems and methods for constructing and assembling a battery are provided. A battery, may comprise a cell tab support and a plurality of stacked battery cells, where a portion of the cells extends through the cell tab support and is folded over on top of the cell tab support. Each of the plurality of stacked battery cells may comprise two oppositely charged electrode tab terminals bent in opposite directions below the cell tab support, and bent in the same direction over the top of the cell tab support.