Electrode Assembly Tab Bonding to Prevent Current Collector Cracks
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Solution Overview
Problem
Current rechargeable lithium batteries experience crack generation in regions between current collector regions with and without tabs due to stress concentration from active material layer expansion, leading to reduced reliability and lifespan.
Innovation Solution
Securing the side surface of a tab to a current collector using a thermoplastic resin to form a continuous securing member, which prevents deformation and crack generation during charging and discharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs are fused to the uncoated portion of the current collector, then electrical connection is achieved, but stress concentration occurs during charge and discharge leading to crack generation
Solution Approach 1:
A securing member comprising thermoplastic resin is introduced as an intermediary between the tab and the current collector. This securing member fills the hollow space adjacent to the tab and bonds the tab to the current collector, distributing stress uniformly and preventing crack generation at the fusion interface while maintaining electrical connection.
2Reliability
If heat-resistant tape or adhesive tape is disposed to cover the uncoated portion, then short circuit prevention is achieved, but stress concentration remains in the hollow space adjacent to the tab
Solution Approach 1:
The securing member acts as a stress-distributing intermediary that fills the hollow space adjacent to the tab. It provides mechanical support and uniform stress distribution during charge and discharge, preventing deformation and crack generation while the tab remains bonded to the current collector.
3Quantity of substance
If the current collector is compressed between electrode plates during charge and discharge, then battery capacity is improved, but deformation occurs in the hollow space adjacent to the tab
Solution Approach 1:
The securing member comprising thermoplastic resin is positioned in advance in the hollow space adjacent to the tab. During charge and discharge, it cushions and distributes the compression stress from electrode plate expansion, preventing deformation and crack generation in the current collector while allowing battery capacity to increase.
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
Enhances the reliability and lifespan of rechargeable lithium batteries by preventing cracks in the current collector regions, improving structural integrity.
Implementation Method 1
a side surface of a tab is secured to a current collector by a thermoplastic resin
Data Source
AI summary
An electrode assembly and a rechargeable lithium battery including the same are disclosed. The electrode assembly can prevent generation of cracks between a current collector region provided with a tab and a current collector region without a tab, thereby improving reliability and lifespan. To this end, the electrode assembly has a structure in which a side surface of the tab is secured to the current collector by a thermoplastic resin.