Cylindrical Battery Electrode Tab Cutting for Damage-Free Winding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cylindrical secondary batteries, substrates are prone to damage during pre-folding and compaction due to irregular bending and increased overlapping, which affects the winding process and electrical connectivity.
Innovation Solution
The cutting depth of uncoated portions is adjusted to 100% to 150% of the forming position, with a gradual increase in cutting width and oblique cutting direction to minimize overlapping and facilitate smooth folding, thereby preventing substrate damage during the winding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substrates are compacted and folded before winding, then electrical connectivity is improved, but substrate damage increases due to irregular bending and overlapping
Solution Approach 1:
The substrate is pre-cut to a depth of 100% to 150% of the forming position A before the folding and winding processes. This preliminary cutting action creates a tab structure that facilitates controlled folding and reduces overlapping during subsequent compaction, thereby preventing substrate damage while maintaining electrical connectivity
Solution Approach 2:
The cutting depth is specifically controlled to be 100% to 150% of the forming position A, creating a localized tab structure only where needed for folding. This localized modification allows the substrate to fold smoothly at specific points without compromising the integrity of the entire substrate structure
2Object-affected harmful factors
If cutting depth is increased to reduce overlapping, then substrate damage is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The cutting depth parameter is optimized to a specific range of 100% to 150% of the forming position A. This parameter change balances the need to reduce overlapping and substrate damage while maintaining achievable manufacturing precision. The defined range provides a buffer that accommodates normal manufacturing variations without compromising substrate integrity
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
A secondary battery includes an electrode assembly which is wound and includes a first electrode plate including a first uncoated portion, a second electrode plate including a second uncoated portion, and a separator between the first electrode plate and the second electrode plate, a case having a cylindrical shape and accommodating the electrode assembly, and a cap assembly sealing the case, and a cutting depth before winding of each of the first uncoated portion and the second uncoated portion is in a range of 100% to 150% as compared with a forming position. When a non-coated portion for forming a substrate tab is cut, a cutting width is changed to increase toward a winding end, thereby minimizing or reducing an overlapping amount between substrates during winding, and damage to the substrate during pre-folding or compaction of the substrate may be prevented or substantially prevented.