Pouch Battery Case Sealing Layout to Prevent Corner Wrinkles
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Solution Overview
Problem
Pouch-shaped battery cases experience wrinkles and defects at the corners of the concave unit due to repetitive vacuum decompression, leading to incomplete sealing and potential openings, which existing technologies fail to prevent effectively.
Innovation Solution
A pouch-shaped battery case design where all corners of the outer edge of the concave unit are sealed, and a non-sealed portion for gas discharge is provided in the middle of one side surface, using a sealing block with specific dimensions and configurations to minimize deformation and prevent wrinkles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a non-sealed portion is formed at the corner of the concave unit for gas discharge, then gas discharge function is improved, but stress concentration and wrinkle formation occur during vacuum decompression
Solution Approach 1:
The non-sealed portion is extracted from the corner position and relocated to the middle of the side surface. This extraction removes the harmful stress concentration effect from the corner while preserving the gas discharge function at the new location.
Solution Approach 2:
Instead of placing the non-sealed portion at the corner as conventionally done, the invention inverts this approach by positioning it at the middle of the side surface, thereby achieving the opposite spatial arrangement that eliminates wrinkle formation.
2Manufacturing precision
If sealing blocks are used to seal all corners, then sealing completeness is improved, but wrinkle formation at corners cannot be completely prevented
Solution Approach 1:
The non-sealed portion is extracted from the corner region, allowing corners to be fully sealed with sealing blocks while preventing wrinkle formation through the alternative positioning of the gas discharge opening.
Solution Approach 2:
The gas discharge function is moved from a two-dimensional corner point to a one-dimensional middle position on the side surface, changing the spatial dimension and thereby eliminating the stress concentration issue.
3Ease of manufacture
If the battery case structure is simplified, then manufacturing cost is reduced, but wrinkle prevention capability is insufficient
Solution Approach 1:
The sealing structure is differentiated by location: corners receive full sealing with sealing blocks while the middle of the side surface remains non-sealed. This local quality differentiation provides wrinkle prevention at corners while maintaining manufacturing simplicity.
Data Source
AI summary
Disclosed are a pouch-shaped battery case including an upper case and a lower case sealed to one another, the upper case and the lower case made of a laminate sheet comprising a metal layer and a resin layer, at least one of the upper case and the lower case having a concave unit for receiving an electrode assembly, the upper case and the lower case being sealed at all corners thereof located along the outer edge of the concave unit, a middle of a first side surface of each of the upper case and the lower case having a non-sealed portion for gas discharge, the first side surface being adjacent to a second side surface of each of the upper case and the lower case through which an electrode terminal extends, a method of manufacturing the pouch-shaped battery case, and a sealing block for manufacturing the pouch-shaped battery case.