Pre-slitting Non-coated Foil to Prevent Wrinkles in Battery Electrode Tabs
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Solution Overview
Problem
The manufacturing process of secondary battery electrodes often results in wrinkles or wave patterns during the slitting process, leading to defects in the electrode tabs due to differences in elongation between coated and non-coated parts, causing the electrode tabs to fold easily and fail under external interference.
Innovation Solution
Incorporating a process of forming non-continuous linear slits in the non-coated part of the metal foil in the second direction before or during the slurry coating, which helps prevent wrinkles and wave patterns from intensifying during the slitting process, thereby reducing defects in the electrode tabs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the slitting process is performed on the electrode current collector after coating, then the electrode strips are formed, but wrinkles or wave patterns are generated in the non-coated part due to differences in elongation between coated and non-coated parts
Solution Approach 1:
The non-coated part of the metal foil is pre-slitted before the electrode slurry is coated and before the final slitting process. This preliminary action creates relief structures in advance that prevent the non-coated part from being folded or wrinkled during subsequent coating and slitting operations, thereby eliminating the root cause of electrode tab defects while maintaining productive electrode strip formation
2Ease of manufacture
If the non-coated part is not pre-slitted, then the coating process is simpler, but the wrinkles or wave patterns intensify during slitting causing electrode tabs to fold easily
Solution Approach 1:
The non-coated part is pre-slitted before coating to create relief structures that prevent wrinkle formation during subsequent processing. This preliminary action adds a simple step that significantly improves electrode tab reliability by preventing folding defects under external interference
Solution Approach 2:
The slitting is applied selectively only to the non-coated part of the metal foil, not the entire electrode. This localized treatment addresses the specific problem area where elongation differences cause wrinkles, while leaving the coated electrode mixture intact, thus improving reliability without overly complicating the overall manufacturing process
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 prevents the elongation and deepening of wrinkles or wave patterns during the slitting process, reducing defects in the electrode tabs and improving the manufacturing process's reliability by maintaining the non-coated part's stability.
Implementation Method 1
In the roll press process, a solvent remaining in the electrode slurry is evaporated, and the electrode slurry is compressed and cured on the electrode to form an electrode mixture layer having improved energy density.
Data Source
AI summary
Disclosed herein is a method of manufacturing an electrode for a secondary battery, including: a process of continuously forming two or more slurry coated parts on one surface or both surfaces of metal foil in a second direction which is a longitudinal direction of the metal foil so that a non-coated part which an electrode slurry is not coated is positioned between the slurry coated parts coated with the electrode slurry including an electrode active material in a first direction which is a transverse direction of the metal foil; a process of forming mixture coated parts by drying the slurry coated parts and rolling by a roller; and a process of forming electrode strips by slitting the non-coated part in the second direction, wherein before continuously forming the slurry coated parts, while continuously forming the slurry coated parts, or between continuously forming the slurry coated parts and forming the mixture coated parts, the method further includes a process of forming non-continuous linear slits in the non-coated part of the metal foil in the second direction.