Traction Battery Pack Tab Welding With Bent Pouch Cell Terminals
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Solution Overview
Problem
Existing methods for assembling traction battery packs face challenges in efficiently and securely electrically connecting battery cells, particularly in ensuring reliable contact and structural integrity between tab terminals of lithium-ion pouch cells.
Innovation Solution
A method involving bending tab terminals of battery cells to specific orientations, securing them with welds, and using a backer tower to facilitate welding, while positioning cross-members to sandwich the terminals for enhanced electrical connection and structural support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tab terminals are directly connected without bending, then the assembly process is simpler, but reliable electrical contact and structural integrity cannot be ensured
Solution Approach 1:
The tab terminals are bent to specific orientations (e.g., 90 degrees) before the welding process to ensure proper alignment and contact. This preliminary shaping action enables reliable electrical connection while maintaining a manageable assembly process.
Solution Approach 2:
A backer tower is introduced as an intermediary component during the welding process. The backer tower provides structural support and ensures proper positioning of the bent tab terminals, facilitating reliable electrical connection without requiring overly complex assembly procedures.
2Reliability
If tab terminals are secured with welding, then electrical connection reliability is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The tab terminals are pre-bent to the correct orientation before welding. This preliminary action ensures that when welding occurs, the terminals are already in the proper position, reducing welding complexity and improving electrical connection reliability.
Solution Approach 2:
The backer tower serves as a mediator during welding, providing a stable base and proper positioning for the tab terminals. This intermediary component simplifies the welding process while ensuring reliable electrical connections.
3Strength
If cross-members are used to sandwich terminals, then structural integrity is enhanced, but device complexity increases
Solution Approach 1:
The battery pack structure is divided into modular sections with cross-members positioned at specific locations to provide structural support. This segmentation approach enhances structural integrity while keeping each module manageable in complexity.
Solution Approach 2:
The cross-members serve multiple functions: they provide structural support, position the tab terminals correctly, and facilitate the sandwiching arrangement for secure connections. This multi-functionality reduces the need for additional components, managing overall device complexity.
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 method effectively electrically connects battery cells, ensuring reliable power transmission and structural integrity within the traction battery pack, enhancing the assembly process efficiency and reliability.
Implementation Method 1
securing the at least one first tab terminal to the at least one second tab terminal with at least one weld
Data Source
AI summary
A method of assembling a battery pack includes bending at least one first tab terminal of at least one first battery cell and then positioning the at least one first battery cell along an axis of a cell stack. The method also includes bending at least one second tab terminal of at least one second battery cell and then positioning the at least one second battery cell along the axis of the cell stack. After the bending, the method secures the at least one first tab terminal to the at least one second tab terminal.