Dry Electrode Calendaring With Tension Control and Direct Lamination
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Solution Overview
Problem
Existing dry manufacturing methods for electrodes in lithium secondary batteries face issues with electrode sheet jams and breakage during the calendaring process, particularly due to variations in feed and transport speed, leading to reduced breaking strength and increased likelihood of sheet breakage.
Innovation Solution
An electrode manufacturing apparatus with a powder sheeting device, calendaring device, and lamination roll, featuring a tension control unit that adjusts the rotational speed of rolling units based on measured tension to stabilize the electrode sheet, and a lamination roll that compresses the sheet immediately after calendaring to minimize breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the calendaring process is repeated multiple times to achieve target thickness, then the electrode sheet thickness is reduced to the desired level, but the breaking strength of the electrode sheet decreases and the likelihood of breakage increases
Solution Approach 1:
The electrode sheet is immediately laminated onto the current collector right after the final calendaring process, before it can be transported through air. This preliminary lamination action prevents the sheet from being exposed to air and potential breakage during transfer, thus maintaining its breaking strength even after multiple calendaring operations
Solution Approach 2:
The current collector serves as an intermediary substrate that receives the electrode sheet immediately after calendaring. By transferring the sheet onto this supportive medium right after rolling, the system eliminates the air transport phase that causes breakage, allowing multiple calendaring passes to be performed safely
2Ease of operation
If the electrode sheet is transported through air after the final calendaring process, then the sheet can be moved to the lamination device, but the likelihood of the electrode sheet breaking increases significantly
Solution Approach 1:
The system maintains continuous contact between the electrode sheet and rolling surfaces from the final calendaring roll through to the lamination roll. This continuous mechanical support eliminates interruptions and air exposure during transport, ensuring the sheet reaches the lamination device without breaking while maintaining operational flow
Solution Approach 2:
The lamination roll acts as an intermediary that receives the electrode sheet directly from the calendaring process without air transport. This intermediary mechanism provides continuous support to the fragile sheet, eliminating the harmful air transport phase while enabling smooth transition to the lamination device
3Ease of operation
If the feed and transport speed of the electrode sheet are not precisely controlled, then the process is simpler to operate, but electrode sheet jams occur frequently during the calendaring process
Solution Approach 1:
The system uses a tension control unit that measures the tension of the electrode sheet during calendaring and provides feedback to adjust the rotational speed of the rolling rolls. This closed-loop control automatically compensates for speed variations and maintains optimal feed rate, preventing jams while keeping the operation simple through automated regulation
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 apparatus stabilizes the calendaring process by minimizing sheet breakage and preventing jams, enhancing process efficiency and economic efficiency in manufacturing dry electrodes.
Implementation Method 1
the electrode sheet and the current collector may be compressed together while passing between the lamination roll and the lower rolling roll
Data Source
AI summary
A dry electrode manufacturing apparatus includes a powder sheeting device configured to shape a dry material including an electrode active material into an electrode sheet and a calendaring device including at least one rolling unit, each rolling unit including a pair of rolling rolls to roll the electrode sheet supplied from the powder sheeting device. The apparatus further includes a lamination roll configured to laminate a current collector and the rolled electrode sheet with a target thickness through the calendaring device to form an electrode. The lamination roll is disposed facing toward one of the pair of rolling rolls of the rolling unit that is last to roll the electrode sheet.