Intermittent Composite Strip Transfer for Copper Foil Integrity

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Solution Overview

Problem

Existing methods for preparing intermittent lithium-copper composite strips face challenges such as damage to the copper foil, incomplete lithium scraping, and unreliable edge separation, which affect the quality and consistency of the composite strips necessary for large battery production.

Innovation Solution

A preparation method for an intermittent composite strip involves acquiring a transfer strip with a load strip and a first composite material strip, where the first composite material strip is intermittently arranged. A second composite material strip with a greater binding force is then used for pressure bonding, ensuring the first composite material strip is securely attached without direct contact that could damage the load strip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a scraper is used to scrape off lithium from lithium foil to form intermittent lithium foil, then the intermittent composite strip can be prepared, but the copper foil current collector is likely to be damaged, scratched or broken

Engineering Contradiction:
Improveintermittent composite strip qualityVSAvoidcopper foil integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces a transfer strip as an intermediary carrier between the lithium foil and the copper foil. The transfer strip receives the intermittent lithium foil through scraping, then transfers it to the copper foil through pressure bonding. This intermediary approach prevents direct contact between the scraper and copper foil, eliminating the risk of copper foil damage while maintaining the intermittent structure formation capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the scraper is in strong contact with the lithium foil, then the intermittent structure can be formed, but the lithium cannot be completely scraped off or the copper foil is damaged

Engineering Contradiction:
Improveintermittent structure formationVSAvoidresidual lithium or copper foil damage
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent segments the lithium foil transfer process into two distinct stages: first, scraping lithium onto the transfer strip in intermittent patterns; second, transferring the formed intermittent lithium structure to the copper foil through pressure bonding. This segmentation allows the scraping operation to be performed independently without risking copper foil damage, while ensuring complete lithium transfer through controlled pressure bonding.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If release agent is used to prevent lithium foil transfer, then intermittent positioning can be achieved, but the lithium foil edge is separated by tearing with poor reliability

Engineering Contradiction:
Improveintermittent positioning accuracyVSAvoidedge separation quality
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The transfer strip serves as an intermediary that receives lithium foil through scraping with release agents for intermittent positioning, then transfers the lithium structure to copper foil through pressure bonding. This intermediary approach allows the use of release agents for precise intermittent positioning without causing edge tearing, as the lithium is transferred through controlled bonding rather than tearing.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method enhances the quality and yield of intermittent composite strips by protecting the composite material from damage and preventing wrinkling, while ensuring reliable separation and consistency, suitable for large battery applications.

Implementation Method 1

performing pressure bonding on a side of the transfer strip including the first composite material strip with the second composite material strip to obtain the intermittent composite strip

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP4506120A1Intermittent composite strip and preparation method, and transfer strip and preparation device and method
Publication Date: 2025.02.12 CHONGQING TIANQI LITHIUM CO LTD
  • EP4506120A1 patent drawingFigure 1~2
  • EP4506120A1 patent drawingFigure 3
  • EP4506120A1 patent drawingFigure 4

AI summary

The present invention relates to the field of preparation of a composite strip, and discloses an intermittent composite strip, a preparation method therefor, a transfer strip, a preparation device and a preparation method therefor. The preparation method for the intermittent composite strip includes the following steps: acquiring the transfer strip, where the transfer strip includes a load strip and a first composite material strip, and the first composite strip is intermittently arranged on the load strip; acquiring a second composite material strip, where a bonding force between the second composite material strip and the first composite material strip is greater than that between the first composite material strip and the load strip under a same pressure; and performing pressure bonding on a side of the transfer strip including the first composite material strip with the second composite material strip to obtain the intermittent composite strip. Through the method, the second composite material strip can be subjected to composite pressure only once and can be protected from being damaged to the greatest extent, thus improving the quality of the intermittent composite strip and increasing the yield thereof.