Secondary Battery Tab Welding Orientation for Stable Laser Joining

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Solution Overview

Problem

Existing secondary battery manufacturing methods face challenges in maintaining uniform welding quality due to varying spatter generation during laser welding of substrate tabs and current collectors, which is influenced by welding direction and orientation.

Innovation Solution

The electrode assembly design includes substrate tabs and current collector plates bent in one direction for surface contact, with laser welding performed parallel to the metal processing direction of the current collector plates, forming back beads on their rear surfaces to improve welding stability and reduce spatter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser welding is performed on substrate tabs and current collectors with varying welding directions and orientations, then welding can be completed, but welding quality becomes non-uniform due to varying spatter generation

Engineering Contradiction:
Improvewelding quality uniformityVSAvoidspatter generation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by standardizing the welding direction to be perpendicular to the rolling direction of the current collector, and by controlling the orientation of substrate tabs to be parallel to the rolling direction. These parameter standardizations reduce variations in spatter generation during laser welding, thereby improving welding quality uniformity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces asymmetric orientation control where substrate tabs are specifically oriented parallel to the rolling direction while the welding direction is set perpendicular to it. This asymmetric arrangement optimizes the welding process by minimizing spatter generation while maintaining effective electrical connection

Inventive Principle:
Principle #4Asymmetry

2Reliability

If substrate tabs and current collectors are processed with different orientations, then assembly flexibility is maintained, but welding stability decreases due to inconsistent spatter generation

Engineering Contradiction:
Improvewelding stabilityVSAvoidorientation control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies orientation control by establishing clear parameter standards: substrate tabs are oriented parallel to the rolling direction and welding is performed perpendicular to the rolling direction. This standardized approach improves welding stability while maintaining manageable device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by pre-orienting substrate tabs parallel to the rolling direction during assembly before welding. This preliminary orientation control ensures consistent welding conditions and improves welding stability without requiring complex real-time adjustments

Inventive Principle:
Principle #10Preliminary action

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 enhances welding stability by minimizing spatter and preventing damage to the electrode assembly, ensuring consistent and high-quality laser welding.

Implementation Method 1

The current collector plates are laser-welded to the first substrate tab and the second substrate tab, respectively

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

the substrate tabs and the current collector may be welded together with a laser

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4375004B1Secondary battery and method of manufacturing said secondary batterie
Publication Date: 2026.03.25 SAMSUNG SDI CO LTD
  • EP4375004B1 patent drawingFigure 1
  • EP4375004B1 patent drawingFigure 2
  • EP4375004B1 patent drawingFigure 3

AI summary

A secondary battery includes: an electrode assembly, a case accommodating the electrode assembly; and a cap assembly sealing the case and including a pair of current collector plates. The electrode assembly includes a first electrode plate having a first substrate tab extending in one direction, a second electrode plate having a second substrate tab extending in another direction, and a separator interposed between the first electrode plate and the second electrode plate. Each of the current collector plates is electrically connected to one of the first substrate tab and the second substrate tab. The current collector plates are laser-welded to the first substrate tab and the second substrate tab, respectively, and a laser welding direction is parallel to a metal processing direction of the corresponding current collector plate.