Battery Module Lead Welding Jig for Precise Laser Lead Joining

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Solution Overview

Problem

Conventional battery module welding processes often damage the module case and deteriorate welding quality, leading to potential heat generation and connection failures due to excessive force transfer and focal distance deviations during electrode lead welding.

Innovation Solution

A battery module design that minimizes force transfer to the module case and cell cartridges by using protruding cell cartridges to guide electrode leads, allowing for precise welding without damaging the case body, and employing a lead welding apparatus with a welding jig that elastically deforms the leads for closer adherence without bending or damaging the module case.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a welding jig presses two electrode leads to be closely adhered during laser welding, then welding quality is improved, but the module case and cell cartridges may be bent or damaged due to excessive force transfer

Engineering Contradiction:
Improvewelding qualityVSAvoidmodule case integrity
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The welding jig is divided into multiple pressing portions that can independently press different regions of the electrode leads. This segmentation allows the pressing force to be distributed and controlled at multiple points, preventing excessive force concentration that could damage the module case while still achieving close adhesion of the electrode leads for high-quality welding

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The welding jig acts as an intermediary tool between the laser welding unit and the electrode leads. It provides controlled pressing force through its pressing portions to ensure close adhesion of the electrode leads during welding, while its design prevents direct transmission of excessive force to the module case and cell cartridges, thus protecting the structural integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the module case is damaged during welding, then the focal distance of the welding unit may be influenced, but this causes deterioration of welding quality and increased contact resistance

Engineering Contradiction:
Improvefocal distance accuracyVSAvoidwelding quality
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The welding jig is designed to prevent damage to the module case before it can occur during the welding process. By providing controlled pressing force through its pressing portions, the welding jig ensures that the module case remains intact and the focal distance of the welding unit is not influenced, thereby preventing deterioration of welding quality and avoiding increased contact resistance

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If external vibration or impact occurs, then the connection between welded electrode leads may be easily broken, but this reduces the reliability of the battery module

Engineering Contradiction:
Improveconnection reliabilityVSAvoidwelded joint strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The welding jig integrates multiple pressing portions that simultaneously press different regions of the electrode leads. This merging of pressing actions at multiple points creates a more robust welded joint that is better resistant to external vibration and impact, thereby improving the reliability of the connection without compromising the welded joint strength

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

Prevents damage to the module case and cell cartridges during welding, enhances welding quality, and reduces the risk of heat generation and short circuits by maintaining precise focal length and improving electrical connections between electrode leads.

Implementation Method 1

a welding unit for welding two electrode leads arranged to overlap each other at the outside of the module case by laser welding

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

a welding jig for pressing one side and the other side of two electrode leads of the battery cells facing each other when the welding is performed so that two electrode leads overlap each other

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3305460B1Battery module, method of welding electrode leads of battery cells, and battery pack comprising the battery module
Publication Date: 2023.12.06 LG ENERGY SOLUTION LTD
  • EP3305460B1 patent drawingFigure 1
  • EP3305460B1 patent drawingFigure 2~3
  • EP3305460B1 patent drawingFigure 4~5

AI summary

Disclosed is a lead welding apparatus, which is used for welding electrode leads of battery cells facing each other, among battery cells of a battery module, and the lead welding apparatus includes a welding unit configured to weld two electrode leads of the facing battery cells to each other, and a welding jig configured to closely adhere the two electrode leads of the facing battery to each other and press the two electrode leads at one side of the two electrode leads, when welding is performed.