Bent Pouch Forming With Arc Slit Cutting to Prevent Cracks
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Solution Overview
Problem
Pouch-type secondary batteries experience cracks during the forming process due to stress concentration at the bending section, and the residual amount of aluminum does not meet the required criteria.
Innovation Solution
Perform arc slit cutting in the pouch adjacent to the bending section to relieve stress and improve the residual amount of aluminum by forming an arc-shaped cutting part at specific angles and distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pouch forming is performed with bent shape, then battery shape adaptability is improved, but stress concentration causes cracks in bending section
Solution Approach 1:
The pouch is segmented by forming an arc-shaped cutting part that divides the continuous material structure into sections. This segmentation relieves stress concentration at the bending section by creating a stress relief zone, preventing cracks while maintaining the bent shape configuration for L-shaped battery adaptability
2Adaptability or versatility
If pouch forming is performed with bent shape, then battery shape adaptability is improved, but residual amount of aluminum decreases
Solution Approach 1:
The arc-shaped cutting part is formed in advance during pouch manufacturing, before the pouch is assembled and put into service. This preliminary action pre-relieves stress at the bending section, preventing future crack formation and aluminum loss, thereby preserving the residual aluminum quantity throughout the battery lifecycle
Data Source
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AI summary
The present invention relates to a method for manufacturing a secondary battery and a secondary battery. The method for manufacturing the secondary battery according to the present invention comprises: 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 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, wherein, in the cutting process, the cutting part is formed at a portion of the pouch, which is adjacent to an inner corner portion in the accommodating part having the bent shape.