Electrode Tab Weld Trace Inspection for Non-Destructive Quality Checks
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Solution Overview
Problem
Existing methods for inspecting the welding quality of electrode tabs and leads in lithium secondary batteries are destructive and unreliable, limiting the ability to conduct comprehensive quality assurance.
Innovation Solution
A non-destructive method using vision inspection to measure the size of welding traces on the electrode lead surface, comparing the measured sizes with reference values to determine if the welds are weak, excessive, or normal, and optionally verifying with tensile strength testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If destructive inspection method (tensile strength measurement) is used to check welding quality, then welding quality can be determined, but total inspection is impossible and only intermittent sample test can be performed
Solution Approach 1:
The patent uses vision inspection to capture images of welding traces and creates a digital copy of the weld appearance. By analyzing the image data (area, perimeter, shape characteristics) instead of physically testing the weld, the system can inspect 100% of welds non-destructively, resolving the contradiction between measurement accuracy and inspection coverage
Solution Approach 2:
The patent replaces the mechanical destructive testing system (tensile strength measurement) with an optical inspection system. The vision inspection device captures images and analyzes welding trace characteristics to determine weld quality, eliminating the need for physical destruction of the weld while maintaining quality assessment capability
2Ease of operation
If inspection area is limited to some pressure points, then inspection can be performed, but reliability decreases
Solution Approach 1:
The patent segments the welding trace into multiple characteristic parameters (area, perimeter, circularity, aspect ratio) and evaluates each parameter against reference values. This comprehensive multi-parameter analysis of the entire welding trace area, rather than limited pressure points, significantly improves inspection reliability while maintaining operational feasibility
Solution Approach 2:
The patent transitions from point-based inspection (pressure points) to area-based inspection by analyzing the two-dimensional welding trace in the image. By evaluating the entire weld area and its geometric properties, the system achieves more reliable quality assessment
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
Enables accurate, non-destructive inspection of all welds, improving reliability and enabling comprehensive quality assessment without damaging the batteries.
Implementation Method 1
recognizing welding traces of the welded portion by a vision inspection device
Implementation Method 2
the ultrasonic welding is a scheme which generates ultrasonic vibrations of 10 to 75 kHz and welds metal through ultrasonic vibration friction heat between metals
Implementation Method 3
friction heat is generated on the contact surface between the electrode tab and the electrode lead, and the electrode tab and the electrode lead are welded by the generated friction heat
Data Source
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AI summary
The present invention relates to a method for inspecting a welding quality of an electrode tab-electrode lead welded portion of a pouch-type lithium secondary battery, and the method includes: recognizing welding traces of the welded portion by a vision inspection device; measuring a size of each of the recognized welding traces; and determining whether the welded portion has been weakly welded, excessively welded or normally welded by comparing the measured size with a reference value.