Pouch Battery Corner Slit Cutting to Prevent Bend Cracks
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Solution Overview
Problem
Pouch-type secondary batteries often experience cracks during the forming process, particularly at the L-shaped section, and fail to meet the required residual aluminum criteria.
Innovation Solution
A method involving slit-cutting an arc-shaped portion of the pouch adjacent to the inner corner of the accommodating part to relieve stress and improve aluminum retention, which includes forming a cutting part in an arc shape during the cutting process, followed by forming a bent-shaped accommodating part and accommodating the electrode assembly within the pouch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pouch is formed in an L-shape without arc slit cutting, then the manufacturing process is simple, but cracks occur in the bending section and residual aluminum amount is insufficient
Solution Approach 1:
The arc-shaped cutting part is formed in advance at the inner corner portion of the pouch before the bending process. This preliminary action removes material that would otherwise concentrate stress during bending, preventing cracks from forming in the bending section while maintaining manufacturing efficiency
Solution Approach 2:
The cutting part is applied locally only at the inner corner portion where stress concentration occurs during bending, rather than uniformly across the entire pouch. This localized modification relieves stress at the critical bending section without unnecessarily complicating the overall pouch structure or reducing aluminum content elsewhere
2Quantity of substance
If the pouch is formed in an L-shape without arc slit cutting, then the manufacturing process is fast, but the residual aluminum amount does not meet criteria
Solution Approach 1:
The arc-shaped cutting is performed as a preliminary step before bending, precisely removing only the necessary material at the inner corner. This approach ensures the residual aluminum amount meets criteria by removing minimal material, while the automated cutting process maintains high manufacturing efficiency
Solution Approach 2:
The cutting is applied locally at the inner corner portion where it is most needed, rather than reducing aluminum uniformly across the pouch. This localized approach maximizes the residual aluminum amount while still achieving crack prevention, thereby maintaining productivity
Data Source
AI summary
A method for manufacturing a secondary battery and a secondary battery are provided. The method for manufacturing the secondary battery includes a cutting process of slit-cutting a portion of a pouch in an arc shape to form a cutting part; a forming process of forming an accommodating part in a bent shape in the pouch to accommodate an electrode assembly having a bent shape in the pouch after the cutting process; and an accommodating process of accommodating the electrode assembly in the accommodating part of the pouch after the forming process. In the cutting process, the portion of the pouch is adjacent to an inner corner portion in the accommodating part having the bent shape.