Cylindrical Battery Cap Assembly for Accurate Sealing Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The conventional method of coupling components in a cylindrical secondary battery is complicated, leading to misalignment and incomplete sealing between the cap assembly and the cylindrical can.

Innovation Solution

A cap assembly is pre-assembled with a cap-up, safety vent, and gasket, where the gasket's upper portion is fused to the cap-up, allowing for simple and accurate alignment and sealing by crimping the cylindrical can without deforming the components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the conventional method of coupling components is used, then the manufacturing process is established, but the coupling process becomes complicated and misalignment occurs between components

Engineering Contradiction:
Improvecoupling process simplicityVSAvoidcoupling process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The gasket is pre-formed with an integrated cap-up structure and safety vent positioning features before assembly. This preliminary formation of the gasket with built-in alignment features eliminates the need for complex coupling processes during final assembly, directly resolving the contradiction between ease of manufacture and device complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cap-up and gasket are merged into a single integrated component rather than separate parts. This merging simplifies the overall structure and eliminates alignment issues between separate components, directly addressing the complexity problem while maintaining ease of manufacture.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If conventional coupling methods are used, then assembly is performed, but misalignment and incomplete sealing occur between cap assembly and cylindrical can

Engineering Contradiction:
Improvesealing completenessVSAvoidcomponent alignment accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The gasket is pre-formed with an integrated cap-up structure and safety vent positioning features before assembly. This preliminary formation of the gasket with built-in alignment features eliminates the need for complex coupling processes during final assembly, directly resolving the contradiction between ease of manufacture and device complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The gasket has varying thickness with a thinner upper portion (20% or less of side surface thickness) that fuses to the cap-up, providing localized sealing quality. This local quality variation ensures complete sealing at critical interfaces while maintaining overall structural integrity, directly addressing the sealing completeness and alignment accuracy contradiction.

Inventive Principle:
Principle #3Local quality

3Reliability

If the gasket upper portion is fused to the cap-up, then sealing is enhanced and alignment is accurate, but additional manufacturing steps are required

Engineering Contradiction:
Improvesealing enhancementVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cap-up and gasket are merged into a single integrated component rather than separate parts. This merging simplifies the overall structure and eliminates alignment issues between separate components, directly addressing the complexity problem while maintaining ease of manufacture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gasket thickness is varied with the upper portion being 20% or less of the side surface thickness. This parameter change enables the upper portion to fuse to the cap-up while the side surface maintains structural integrity, achieving enhanced sealing without excessive manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If crimping is performed without component deformation, then component integrity is maintained, but precise control of crimping load is required

Engineering Contradiction:
Improvecomponent integrityVSAvoidcrimping process control
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The gasket has varying thickness with a thinner upper portion (20% or less of side surface thickness) that fuses to the cap-up, providing localized sealing quality. This local quality variation ensures complete sealing at critical interfaces while maintaining overall structural integrity, directly addressing the sealing completeness and alignment accuracy contradiction.

Inventive Principle:
Principle #3Local quality

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 method ensures structurally accurate alignment and enhanced sealing, minimizing crimping load and component deformation, thereby simplifying the manufacturing process and improving the battery's integrity.

Implementation Method 1

the upper portion of the gasket may be fused to the peripheral upper side of the cap-up

Methodology Applied
Scientific EffectFusion: Welding

Data Source

PatentEP4597659A1Secondary battery
Publication Date: 2025.08.06 SAMSUNG SDI CO LTD
  • EP4597659A1 patent drawingFigure 1~2
  • EP4597659A1 patent drawingFigure 3A
  • EP4597659A1 patent drawingFigure 3B

AI summary

A secondary battery including an electrode assembly 110 formed by winding a positive electrode sheet, a negative electrode sheet, and a separator interposed therebetween; a cylindrical can 130 configured to accommodate the electrode assembly; and a cap assembly 150 coupled to an open upper portion of the cylindrical can. The cap assembly includes a cap-up 151 having an upwardly protruding structure, a safety vent 153 disposed below the cap-up while surrounding an outer circumference of the cap-up, and a gasket 155 for sealing between the cap assembly and the cylindrical can. The gasket includes a side surface surrounding outer circumferential surfaces of the cap-up and the safety vent and includes an upper portion bent inwardly to cover a peripheral upper side of the cap-up.