Cylindrical Electrode Assembly Bonding to Prevent Unwinding Stress

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Solution Overview

Problem

Existing secondary batteries face issues with internal stress at the electrode assembly, particularly at the winding end, which can lead to unwinding and structural instability.

Innovation Solution

The use of an adhesive part with specific patterns and configurations, such as parallel, spaced, or overlapping designs, to adhere and fix the outermost surface of the electrode assembly, reducing the need for a sealing tape and minimizing mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a sealing tape is used to fix the winding end of the electrode assembly, then the structural integrity is improved, but the internal stress and device complexity increase

Engineering Contradiction:
Improvestructural integrityVSAvoidinternal stress
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The patent removes the sealing tape component entirely and replaces it with an adhesive part integrated directly onto the electrode assembly. This extraction of the separate sealing tape eliminates the material difference between tape and electrode assembly, thereby reducing internal stress while maintaining structural integrity through the adhesive bonding function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fixing method from mechanical (sealing tape wrapping) to chemical bonding (adhesive part). This parameter change in the bonding mechanism eliminates the need for additional materials and reduces internal stress while maintaining the structural integrity of the electrode assembly winding end.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If a sealing tape is used to fix the winding end, then structural integrity is improved, but the internal space of the case is reduced

Engineering Contradiction:
Improvestructural integrityVSAvoidinternal space of case
Core Design Contradiction:
Stability of the object's compositionVSVolume of stationary object

Solution Approach 1:

By removing the sealing tape and using a minimal adhesive part instead, the patent reduces the space occupied at the winding end. This extraction of the bulky sealing tape component directly increases the internal space of the case while maintaining structural integrity through the adhesive bonding.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If adhesive part patterns are spaced apart or overlapping, then manufacturing flexibility is improved, but the adhesive material usage varies

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidadhesive material usage
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The adhesive part is divided into multiple patterns that can be arranged in different configurations (spaced apart or overlapping). This segmentation allows manufacturing flexibility to be improved as different patterns can be selected based on specific requirements, while the total adhesive material usage can be controlled by adjusting the pattern density and overlap程度.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach maintains structural integrity by preventing unwinding of the electrode assembly and reducing internal stress, while minimizing adhesive usage and avoiding stress from material differences.

Implementation Method 1

an adhesive part adhering and fixing a winding end of an outermost surface of the electrode assembly

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

The adhesive part may be fixed to the outermost surface by heat fusion

Methodology Applied
Scientific EffectHeat fusion:

Data Source

PatentEP4636879A1Secondary battery
Publication Date: 2025.10.22 SAMSUNG SDI CO LTD
  • EP4636879A1 patent drawingFigure 1
  • EP4636879A1 patent drawingFigure 2a
  • EP4636879A1 patent drawingFigure 2b

AI summary

One or more embodiments relates to a secondary battery capable of suppressing internal stress of the side of the electrode assembly, and capable of ensuring internal space of a case. The secondary battery according to one or more embodiments includes a case defining a space therein, an electrode assembly in the case and including a positive electrode plate, a negative electrode plate, and a separator wound in a cylindrical shape, and an adhesive part adhering and fixing a winding end of an outermost surface of the electrode assembly, and a cap assembly sealing the case.