Cylindrical Battery End Structure for Clear Probe Contact

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Solution Overview

Problem

Cylindrical batteries face issues with weld marks interfering with probes or bus plates and are prone to corrosion and rust due to exposed welding tracks.

Innovation Solution

The welding tracks are positioned away from the center of the first surface, covered by a protection piece, and designed to ensure a sufficient area for electrical connections, reducing interference and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If welding tracks are located at the bottom center of the battery housing, then electrical connection between current collecting disc and housing is achieved, but weld marks interfere with probe contact and bus plate connection

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidprobe contact accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent divides the bottom surface into functional zones: a central first area free of welding tracks for probe and bus plate access, and a peripheral second area containing welding tracks for electrical connection. This spatial segmentation resolves the contradiction by separating conflicting functions to different locations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-point welding approach to a distributed welding pattern around the periphery, utilizing the radial dimension of the circular bottom surface. This allows electrical connection functionality to be achieved through multiple peripheral welding tracks rather than a central weld, clearing the center area for probe access.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If welding tracks are exposed on the battery surface, then electrical connection is established, but the welding tracks are prone to corrosion and rust from environmental exposure

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidcorrosion and rust from moisture and oxygen
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a protective coating as an intermediary layer between the welding tracks and the external environment. This coating acts as a barrier that prevents moisture and oxygen from reaching the welding tracks, thereby eliminating corrosion and rust while preserving the electrical connection functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective coating creates a protective shell that replicates the protective function needed for the welding tracks, shielding them from harmful environmental factors without interfering with their electrical connection purpose.

Inventive Principle:
Principle #26Copying

3Ease of operation

If welding tracks are positioned away from the center, then probe and bus plate access is improved, but welding stability may be affected by housing chamfer interference

Engineering Contradiction:
Improveprobe and bus plate accessibilityVSAvoidwelding quality consistency
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies local quality by designing the protective coating to have different coverage requirements in different areas: the first area (center) remains completely exposed for access, while the second area (periphery) receives protective coating coverage. This localized differentiation optimizes both accessibility and protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The protective coating is applied in advance to cover the welding tracks before the battery undergoes chemical formation or voltage testing. This preliminary protective action ensures that welding tracks are already protected from corrosion before any potential exposure to harsh test conditions or long-term use.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4416790B1Battery and battery pack
Publication Date: 2026.01.21 DONGGUAN AMPEREX TECH
  • EP4416790B1 patent drawingFigure 1
  • EP4416790B1 patent drawingFigure 2~3
  • EP4416790B1 patent drawingFigure 4~5

AI summary

This application relates to a cylindrical battery, including: a housing, an electrode assembly, a first current collecting disc, and a protection piece. The housing contains a first end portion. The electrode assembly is accommodated in the housing. The first current collecting disc is electrically connected to the electrode assembly in the housing. The first end portion contains several welding track configured to be connected to the first current collecting disc. The first end portion further contains a first surface oriented away from the first current collecting disc. On the first surface, the welding track are arranged away from a center of the first surface. The protection piece is sheathed around the housing, extends beyond the first surface, and covers the welding track. No welding track is arranged at the center of the first surface. A bus plate and a probe can be directly electrically connected to the first end portion near the center of the first surface, thereby reducing interference between the welding track and the bus plate or probe, facilitating electrical connection between the first end portion and the bus plate or probe. In addition, the protection piece covers the welding track, thereby effectively reducing contact between outside air and the welding track, and reducing corrosion and rust at the welding track.