Z-Folded Cell Stack Wrapping With Buffered Separator Tension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing Z-folded cell stacks face challenges in ensuring process safety and efficiency, particularly in large-scale production of battery cells for electric vehicles, where maintaining accurate stacking and wrapping of cell components with different sizes is difficult, leading to potential errors and increased cycle times.
Innovation Solution
An apparatus and method that involve alternately stacking first and second cell components with a separator web in a Z-shape, severing the web using a movable gripper, and wrapping it around the stack while maintaining constant tension, allowing for parallel processing of stacking and wrapping, and using a buffer storage to manage web length and tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sequential processing (stacking then wrapping) is used, then process simplicity is maintained, but cycle time increases and productivity decreases
Solution Approach 1:
The separator web is fed and positioned in advance during the stacking process, and the wrapping operation is prepared beforehand. The separator web insertion device pre-positions the separator web between cell components during stacking, while the wrapping device is ready to immediately wrap the completed stack, enabling seamless parallel execution and reducing idle time between operations.
Solution Approach 2:
The patent implements continuous operation by having the stacking device and wrapping device operate simultaneously without interruption. While one cell stack is being wrapped, the stacking device immediately begins assembling the next cell stack, ensuring that both devices are continuously productive and eliminating waiting time that would occur in sequential processing.
2Manufacturing precision
If cell components of different sizes are stacked, then adaptability is improved, but stacking accuracy decreases due to alignment difficulties
Solution Approach 1:
The patent applies different structural characteristics to different parts of the cell components. Edge portions of the cell components are designed with uniform dimensions to facilitate precise alignment and stacking, while the central active areas can vary in size to accommodate different battery capacities and configurations. This allows accurate stacking while maintaining adaptability to different product requirements.
3Manufacturing precision
If separator web tension is not controlled, then device complexity is reduced, but manufacturing precision deteriorates due to electrode slippage
Solution Approach 1:
The patent incorporates a tension control device that continuously monitors and adjusts the tension of the separator web during the stacking process. Sensors detect variations in web tension, and the control system automatically adjusts the feeding rate or applies corrective forces to maintain optimal tension levels, preventing electrode slippage and ensuring precise stacking without requiring complex mechanical tensioning mechanisms.
Data Source
AI summary
A method and an apparatus for manufacturing Z-folded cell stacks. First and second cell components are alternately stacked while a separator web is inserted in between in a Z-shaped or meandering manner and is subsequently wrapped one more time around the cell stack thus obtained. Wrapping is performed at least in part in parallel with a previously obtained cell stack while stacking of the next cell stack is performed. A supply of the separator web required for wrapping is provided in a separator buffer storage, is cut off and held at the trailing end, in the conveying direction, with a separating gripper and is fed with the separating gripper during wrapping.