Electrode Tab Welding Structure for Pore-Free Lead Bonding
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Solution Overview
Problem
Welding defects occur when coupling electrode tabs to an electrode lead in secondary batteries, leading to incomplete contact and porosity, which existing technologies fail to prevent effectively.
Innovation Solution
An electrode assembly with pressure welding portions of different sizes and shapes on the bundle of electrode tabs, combined with an ultrasonic welding apparatus featuring protrusions of varying sizes on the horn and anvil, to ensure proper alignment and contact during welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser welding is performed to connect the bundle of electrode tabs to the electrode lead, then the connection is achieved, but welding defects occur due to pores formed between the electrode tabs and electrode lead
Solution Approach 1:
The patent applies preliminary ultrasonic welding to compress the bundle of electrode tabs and eliminate pores before performing laser welding. This preliminary compression action removes the harmful spaces that would otherwise cause welding defects during the subsequent laser welding process, ensuring proper contact between the electrode tabs and electrode lead.
2Ease of manufacture
If uniform pressure welding portions are used on the bundle of electrode tabs, then the manufacturing process is simplified, but the coupling force between the bundle and electrode lead is insufficient
Solution Approach 1:
The patent implements local quality by creating pressure welding portions with different areas at different locations on the bundle of electrode tabs. The first pressure welding portion has a larger area to provide strong coupling force at the connection point with the electrode lead, while the second pressure welding portion has a smaller area. This non-uniform distribution optimizes the coupling strength where needed without unnecessarily complicating the overall manufacturing process.
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 configuration enhances the coupling force between the electrode tabs and the electrode lead, preventing welding defects and ensuring a strong, defect-free connection by optimizing the pressure welding portions and using ultrasonic waves for precise bonding.
Implementation Method 1
an ultrasonic welding apparatus configured to manufacture the same
Data Source
AI summary
Disclosed is an electrode assembly formed in a structure in which a plurality of positive electrodes with bundled positive electrode tabs and a plurality of negative electrodes with bundled negative electrode tabs are alternately stacked, each of the bundles of electrode tabs includes a first surface connected to a corresponding electrode lead and a second surface opposite the first surface, the first surface includes a plurality of first pressure welding portions and a plurality of first non-pressure, the second surface includes a plurality of second pressure welding portions and a plurality of second non-pressure welding portions The area of one of the first pressure welding portions is less than the area of one of the second pressure welding portions.