Patterned Electrode Lead Film for Sealing Strength and Low Resistance

Solution Overview

Problem

The existing electrode leads in lithium secondary batteries face issues with reduced sealing strength and increased resistance and heat generation due to the use of polymer lead films, leading to stability and life characteristic degradation.

Innovation Solution

The electrode lead features a metal terminal with a film layer having engraved patterns on its surface, arranged at equal intervals, which reduces contact resistance and heat generation while maintaining sealing strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a film layer is formed on the surface of the electrode lead through surface treatment to improve sealing strength, then sealing strength between the lead film and electrode lead is improved, but resistance of the surface is increased and heat generation is increased

Engineering Contradiction:

Improvesealing strengthVSAvoidresistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The film layer is designed with different regions having different properties: a first region with higher film layer thickness for improved sealing strength, and a second region with lower film layer thickness for reduced resistance and heat generation. This local differentiation allows simultaneous optimization of both sealing performance and electrical performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the thickness parameter of the film layer across different regions. By controlling the film layer thickness to be non-uniform (first region thicker than second region), the patent optimizes the balance between sealing strength and electrical resistance, resolving the contradiction between these two requirements.

Inventive Principle:

Principle #35Parameter changes

2Strength

If a film layer is formed on the surface of the electrode lead through surface treatment to improve sealing strength, then sealing strength between the lead film and electrode lead is improved, but amount of heat generated is increased

Engineering Contradiction:

Improvesealing strengthVSAvoidheat generation

Core Design Contradiction:

StrengthVSTemperature

Solution Approach 1:

The film layer is designed with different regions having different properties: a first region with higher film layer thickness for improved sealing strength, and a second region with lower film layer thickness for reduced resistance and heat generation. This local differentiation allows simultaneous optimization of both sealing performance and thermal performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the thickness parameter of the film layer across different regions. By controlling the film layer thickness to be non-uniform (first region thicker than second region), the patent optimizes the balance between sealing strength and heat generation, resolving the contradiction between these two requirements.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4683096A1Electrode lead, manufacturing method therefor, and lithium secondary battery comprising same

Publication Date: 2026.01.21 LG ENERGY SOLUTION LTD

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AI summary

The present invention relates to an electrode lead electrically connected to an electrode assembly, the electrode lead including a metal terminal; and a film layer which is disposed on the metal terminal and has two or more patterns engraved on a surface of the film layer, wherein the two or more patterns are arranged apart from each other at equal intervals in a direction parallel to the film layer, and each of the patterns includes a side surface and a bottom surface.