Secondary Battery Lead Tab Induction Bonding Without Film Deformation

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Solution Overview

Problem

The existing methods for bonding a metal lead and insulating films in secondary batteries are time-consuming and prone to deformation, leading to reduced productivity and adhesion issues.

Innovation Solution

A lead tab design incorporating magnetic members in the insulation films, which are induction-heated using alternating magnetic fields, allowing simultaneous bonding of the metal lead and insulation films, reducing the overall process time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resistance heater is used for bonding metal lead and insulating film, then bonding can be achieved, but process time becomes excessive due to low thermal conductivity of insulating film

Engineering Contradiction:
Improvebonding qualityVSAvoidprocess time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the resistance heater (thermal conduction system) with an induction heating system that uses electromagnetic fields to directly heat the metal lead. This substitution of heating mechanism allows rapid heating of the metal lead without relying on thermal conduction through the insulating film, thereby significantly reducing process time while maintaining bonding quality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies local quality by concentrating the heating action only on the metal lead portion that requires bonding, rather than heating the entire insulating film. The induction heating coil is positioned to generate alternating magnetic fields that induce eddy currents specifically in the metal lead, creating localized rapid heating at the bonding interface without excessive heat affecting the insulating film.

Inventive Principle:
Principle #3Local quality

2Loss of time

If temperature of resistance heater is increased to shorten process time, then process time decreases, but insulating film deforms resulting in lowered adhesion

Engineering Contradiction:
Improveprocess timeVSAvoidfilm deformation
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The induction heating system applies heat locally and selectively to the metal lead at the bonding interface, rather than uniformly heating the entire insulating film. This localized heating approach allows rapid temperature increase in the metal lead to achieve bonding within seconds, while the insulating film remains at lower temperatures and maintains its structural integrity and adhesion properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

By replacing the resistance heater with induction heating, the patent eliminates the need for high-temperature uniform heating of the insulating film. The electromagnetic induction method enables precise control of heating location and intensity, allowing process time reduction without causing film deformation or adhesion loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of time

If high-frequency induction heating is used to bond metal lead and insulating film, then process time shortens, but bonding between insulating films becomes impossible requiring additional processes

Engineering Contradiction:
Improvebonding process timeVSAvoidnumber of bonding processes
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent merges multiple bonding operations into a single induction heating step. By positioning the insulating films on both sides of the metal lead and applying induction heating simultaneously, the system achieves bonding between the metal lead and both insulating films in one process, eliminating the need for separate bonding steps and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The induction heating system performs multiple bonding functions simultaneously - it bonds the metal lead to the lower insulating film and the metal lead to the upper insulating film in a single operation. This multi-functional approach replaces the need for separate bonding processes, reducing both time and process complexity.

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

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 significantly shortens the bonding process time, enhances productivity, and maintains adhesion without film deformation, thereby improving the manufacturing efficiency of secondary batteries.

Implementation Method 1

each of the first insulation film and the second insulation film includes a magnetic member that is induction-heated by an alternating magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a magnetic member that is inductively heated by an alternating magnetic field

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Data Source

PatentEP3886197B1Lead tab for secondary battery, manufacturing apparatus thereof, and secondary battery comprising same
Publication Date: 2025.10.22 LG ELECTRONICS INC
  • EP3886197B1 patent drawingFigure 1
  • EP3886197B1 patent drawingFigure 2~3
  • EP3886197B1 patent drawingFigure 4

AI summary

A lead tab for a secondary battery, according to an embodiment of the present invention, includes a metal lead having a long rectangular plate shape in a first direction, a first insulation film formed on a lower surface of the metal lead in a second direction crossing the first direction, and a second insulation film formed on an upper surface of the metal lead in the second direction so as to correspond to the first insulation film, wherein each of the first insulation film and the second insulation film has a magnetic member which is induction-heated by an alternating magnetic field.