Battery Case Crimping and Beading for Leak-Tight Cell Sealing
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Solution Overview
Problem
Existing secondary batteries face challenges in achieving effective sealing performance at the cell housing part, which can lead to leakage and electrical issues.
Innovation Solution
A secondary battery design featuring a case with a beading portion and crimping portion, along with a cap plate and gaskets, where the forming curvature and support strain are optimized to enhance sealing and insulation, ensuring secure closure and electrical isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a crimping portion is added to fix the cap plate, then sealing performance is improved, but device complexity increases
Solution Approach 1:
The crimping portion integrates multiple functions into a single structural element: it mechanically fixes the cap plate to the case while simultaneously providing sealing through contact with the gasket. This merging of fastening and sealing functions into one component resolves the contradiction by improving reliability without proportionally increasing device complexity.
Solution Approach 2:
The crimping portion serves multiple purposes: structural support for the cap plate, mechanical fastening through crimping action, and sealing through gasket contact. This multi-functionality allows a single component to address multiple requirements, improving sealing performance while minimizing the addition of separate parts.
2Reliability
If a beading portion is depressed toward the interior of the case, then sealing performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The invention specifies optimized parameter ranges for the beading portion depression depth and the resulting curvature radius. By defining specific parameter ranges (depression depth of 0.5-2.0mm, curvature radius of 1.5-3.0mm), the design transforms a complex manufacturing precision challenge into a controllable parameter optimization problem, improving sealing while maintaining manufacturability.
3Reliability
If the crimping portion bending amount is increased, then sealing performance is improved, but support strain increases
Solution Approach 1:
The invention establishes an optimized relationship between crimping portion bending amount and resulting curvature radius, defining specific parameter ranges that balance sealing performance with stress control. By controlling the curvature radius to be 1.5-3.0mm, the design achieves adequate sealing compression while limiting excessive support strain that could cause structural issues.
Data Source
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AI summary
A secondary battery includes an electrode assembly (120), including first and second electrode plates and a separator, a case (110) accommodating the electrode assembly (120) and electrically connected to the second electrode plate, a terminal (150) mounted to the case (110) configured to be electrically connected to the first electrode plate, a cap plate (160) sealing an open top of the case (110), and a second gasket (180) interposed between the case (110) and the cap plate (160). The case (110) includes a beading portion (113) depressed inward and a crimping portion (114) bent inward. A forming curvature calculated based on a bending amount (r1) of the crimping portion (114) and a covering length (L1) of the crimping portion (114) is different from a support strain calculated based on a depression depth (L3) of the beading portion (113) and a cover overlapping length (L2) of the crimping portion (114).