Cylindrical Battery Crimping Region Impact Absorption

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Solution Overview

Problem

Cylindrical secondary batteries face issues with sealability and safety due to deformation of the crimping region under external impacts and increased internal pressure, leading to electrolyte leakage and potential fires or explosions.

Innovation Solution

The crimping region is designed with a sidewall inclination of 1 to 8 degrees inward and a bent front end at 60 to 85 degrees, allowing for effective absorption of external impacts and maintaining sealability, preventing deformation and electrolyte leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the crimping region is formed with a conventional structure, then the cap assembly can be mounted to the container, but the crimping region deforms under external impacts and internal pressure, leading to electrolyte leakage

Engineering Contradiction:
ImprovesealabilityVSAvoidresistance to deformation
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the geometric parameters of the crimping region by introducing a sidewall inclination angle (α) of 1 to 8 degrees and a bent front end angle (β) of 60 to 85 degrees. These parameter modifications optimize the structural strength distribution, allowing the crimping region to resist deformation under external impacts and internal pressure while maintaining proper sealing function.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces asymmetry to the conventional vertical crimping structure by inclining the sidewall at angle α and bending the front end at angle β. This asymmetric design creates a more robust structure that better withstands external impacts and internal pressure, preventing the deformation that occurs in symmetric conventional designs.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the crimping region is strengthened to prevent deformation, then safety improves, but the complexity of the structure increases

Engineering Contradiction:
ImprovesafetyVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Rather than adding complex components or structures, the patent achieves enhanced safety by modifying the geometric parameters of the existing crimping region structure. The sidewall inclination angle (α = 1 to 8 degrees) and bent front end angle (β = 60 to 85 degrees) provide the necessary strength while maintaining structural simplicity and ease of manufacturing.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2062309B1Cylindrical secondary battery of improved safety
Publication Date: 2012.10.31 LG CHEM LTD
  • EP2062309B1 patent drawingFigure 1~2
  • EP2062309B1 patent drawingFigure 3~4
  • EP2062309B1 patent drawingFigure 5

AI summary

Disclosed herein is a cylindrical secondary battery constructed in a structure in which a crimping region, at which a cap assembly is mounted to the open upper end of a cylindrical container having an electrode assembly mounted therein, is formed at the upper end of the container, wherein the crimping region is constructed in a structure in which the upper end of the crimping region is gently bent at a predetermined radius of curvature (R), such that the crimping region surrounds a gasket located at the inside of the crimping region, the bent front end extends inward, such that the bent end presses the gasket, and an inclination of a predetermined angle is formed at the sidewall of the crimping region, such that the upper part of the crimping region is directed inward. According to the secondary battery of the present invention, the sealability of the gasket is improved, and external impacts are partially absorbed by the inclination formed at the crimping region. Consequently, the deformation of the crimping region is minimized, whereby the leakage of the electrolyte is prevented, and the safety of the battery is greatly improved.