Electrode Assembly Lamination System for Prismatic Cells
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Solution Overview
Problem
The existing secondary-cell manufacturing processes face challenges in forming electrode assemblies for prismatic and pouch cells, including complex manufacturing, high defect rates, and costly facility investments, due to the need for intricate folding and arrangement of unit-cells over long sheets, which complicates the process and increases the risk of short circuits.
Innovation Solution
A secondary-cell manufacturing system that forms electrode assemblies through lamination by using a unit-cell-forming device to stack separator/negative cell/separator/positive cell/separator, an overturning device to create inverse unit-cells, and a stacking device to arrange these in a simplified manner, reducing the complexity and defect rate through the use of guides, cutters, Laminators, and robot arms for precise placement and integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the stack-folding electrode assembly method is used to manufacture prismatic or pouch cells, then the electrode assembly can be formed, but the manufacturing process becomes very complex and requires costly facility investment
Solution Approach 1:
The electrode assembly manufacturing process is segmented into independent modules: a lamination module that stacks separator, negative electrode, and positive electrode layers separately, and a folding module that folds the stacked structure. This segmentation eliminates the need for complex long-sheet arrangement and folding operations, simplifying the overall manufacturing process while maintaining the ability to produce prismatic and pouch cell formats.
Solution Approach 2:
The invention inverts the conventional manufacturing sequence by first laminating the electrode layers in a simplified stacked configuration and then folding the entire structure, rather than arranging and folding long sheets in the conventional sequence. This inversion transforms a complex process into a simpler two-stage process that reduces facility requirements and investment costs.
2Reliability
If the stack-folding electrode assembly method is used, then the electrode assembly can be formed, but the defect rate increases due to difficulty in cutting and arranging unit-cells
Solution Approach 1:
The lamination process performs preliminary stacking and alignment of separator, negative electrode, and positive electrode layers with precise positioning before folding occurs. This preliminary action ensures that all layers are correctly aligned and secured, eliminating defects that would otherwise occur during the difficult cutting and arrangement stages of conventional methods.
Solution Approach 2:
The invention merges the stacking and alignment operations into a single lamination process, where multiple electrode layers are simultaneously stacked and bonded in the correct sequence. This merging eliminates the need for separate cutting and arrangement operations, reducing the defect rate caused by misalignment and handling errors.
3Productivity
If jelly-rolled electrode assembly is used for cylindrical cells, then the manufacturing is optimized, but the electrode activating agent peels when applied to prismatic or pouch cells due to localized stress
Solution Approach 1:
The invention segments the electrode assembly into discrete stacked layers that are laminated and then folded, rather than using the continuous jelly-rolled structure. This segmentation allows the electrode structure to better accommodate the localized stress and expansion/contraction that occurs during charge-discharge cycles in prismatic and pouch cells, preventing the peeling of electrode activating agent while maintaining manufacturing efficiency.
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 approach simplifies the manufacturing process, reduces the defect rate of electrode assemblies, and allows for easier preparation and placement of unit-cells, thereby decreasing the frequency of rework and enhancing the overall efficiency of electrode assembly production.
Implementation Method 1
Laminator 1 and Laminator 2 that handles the orderly stacking and integration of separator, negative unit-cells that are arranged with a specified interval, separator, positive unit-cells that are arranged with a specified interval, and separator
Data Source
AI summary
The secondary-cell manufacturing system that forms the electrode assembly with lamination as demonstrated includes the unit-cell-forming device that forms a unit-cell from a separator roll, negative-cell roll, and positive-cell roll as stacked in the order of separator/negative cell/separator/positive cell/separator, the overturning device that forms an inverse unit-cell stacked in the order of separator/positive cell/separator/negative cell by overturning a portion of minimum 2 cells that are formed by the unit-cell-forming device, and the stacking device that performs stacking in the order of unit-cell/negative cell/inverse unit-cell/positive cell. Accordingly, the invention provides a secondary-cell manufacturing system that forms an electrode assembly, which simplifies the process for building the electrode assembly, reduces the defect rate for the built electrode assembly, and forms the electrode assembly with lamination.