Cylindrical Battery Cap Structure for One-End Bus Bar Connection

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Solution Overview

Problem

The existing cylindrical secondary battery structure complicates electrical connections between batteries due to separate positive and negative electrodes, requiring bus bars at both ends and increasing processing time, and includes a gasket for sealing, which occupies space and reduces the capacity-to-height ratio.

Innovation Solution

The cylindrical secondary battery design integrates both positive and negative electrodes at one end, allowing for simplified bus bar connections and omits the separate gasket by welding the cap plate to the cylindrical can, reducing height and enhancing capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If separate positive and negative electrodes are provided at both ends of the cylindrical secondary battery, then electrical connection between batteries is achieved, but the bus bar connection structure becomes complex and processing time increases

Engineering Contradiction:
Improvebus bar connection simplicityVSAvoidconnection structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines both positive and negative electrodes at one end of the cylindrical secondary battery, allowing bus bars to connect to both electrodes at a single location. This merging of electrode positions simplifies the connection structure and reduces processing time compared to connecting to separate ends.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cap assembly serves multiple functions: it seals the can, provides electrical connection points for both positive and negative electrodes, and facilitates simplified bus bar connections. This multi-functionality reduces the need for separate connection structures at different ends of the battery.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a gasket is used to seal the cap assembly to the cylindrical can, then sealing is achieved, but the overall height of the battery increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidbattery height
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent removes the gasket from the sealing structure between the cap assembly and cylindrical can. Instead of using a separate gasket component, the sealing function is integrated directly into the cap assembly through welding, eliminating the need for additional sealing layers and reducing battery height.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing function is merged with the cap assembly structure itself. The cap assembly is directly welded to the cylindrical can, combining the sealing function with the structural component, thereby eliminating the need for a separate gasket and reducing overall height.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a gasket is used for sealing the cap assembly, then sealing is provided, but the capacity to height ratio decreases

Engineering Contradiction:
Improvesealing functionVSAvoidcapacity to height ratio
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The gasket is extracted from the sealing system, eliminating the space it occupies between the cap assembly and cylindrical can. This increases the internal volume available for electrodes and electrolyte, thereby improving the capacity to height ratio while maintaining sealing through direct welding.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing function is merged into the cap assembly structure through welding, eliminating the need for a separate gasket layer. This reduces the height occupied by sealing components and increases the effective capacity volume, improving the capacity to height ratio.

Inventive Principle:
Principle #5Merging (Combining)

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 design simplifies the bus bar connection structure and increases the capacity-to-height ratio by eliminating the need for a separate gasket, facilitating efficient electrical connections and optimizing battery height.

Implementation Method 1

a cap plate coupled at the lower end of the cylindrical can, the cap plate being sealed to the lower end of the cylindrical can by welding

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4258434A1Cylindrical secondary battery
Publication Date: 2023.10.11 SAMSUNG SDI CO LTD
  • EP4258434A1 patent drawingFigure 1
  • EP4258434A1 patent drawingFigure 2
  • EP4258434A1 patent drawingFigure 3~4A

AI summary

A cylindrical secondary battery includes: an electrode assembly including a positive electrode plate, a separator, and a negative electrode plate; a cylindrical can accommodating the electrode assembly, a lower end of the cylindrical can being electrically connected to the negative electrode plate; a terminal passing through a top surface of the cylindrical can and electrically connected to the positive electrode plate; and a cap plate coupled at the lower end of the cylindrical can. The cap plate is sealed to the lower end of the cylindrical can by welding.