Cylindrical Battery Weld State Inspection via 4-Wire Resistance
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Solution Overview
Problem
Conventional methods for inspecting the welding state of cylindrical batteries are destructive and time-consuming, leading to inefficiencies and potential battery damage.
Innovation Solution
A non-destructive method for inspecting the welding state of cylindrical batteries using resistance measurements with 4-wire low-resistance direct current method, involving multiple probe units to measure resistance values at different points on the current collector plates and can housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If destructive inspection method is used to inspect welding states, then welding quality can be determined, but production efficiency decreases and batteries are damaged
Solution Approach 1:
The patent replaces the mechanical destructive inspection method with an electrical measurement system. By measuring resistance values between current collector plates and can housing, the welding quality is determined without physically damaging the battery, thus maintaining production efficiency while achieving accurate welding state inspection.
Solution Approach 2:
The patent introduces resistance measurement as an intermediary method to assess welding quality. Instead of directly observing or physically testing the weld joints, the system uses electrical resistance as a proxy indicator, allowing non-destructive evaluation of welding states through probe units that measure resistance values.
2Measurement precision
If manual sampling inspection is performed, then welding states can be assessed, but inspection time increases and not all batteries are inspected
Solution Approach 1:
The patent creates a universal inspection system that can inspect all batteries in the production line using the same resistance measurement methodology. The probe units are designed to universally measure welding states at multiple locations (current collector plates and can housing) without requiring different inspection methods for different battery positions, enabling total inspection rather than selective sampling.
Solution Approach 2:
The inspection method is integrated into the production line to perform welding state assessment immediately after welding operations. By conducting resistance measurements at this preliminary stage, the system identifies defective batteries early in the production process, preventing defective products from progressing further and reducing overall inspection time.
3Manufacturing precision
If multiple welding points are inspected individually, then comprehensive welding quality can be achieved, but inspection complexity increases
Solution Approach 1:
The patent merges multiple inspection functions into a unified resistance measurement system. By measuring the total resistance between current collector plates and can housing, the system simultaneously evaluates multiple welding points (welding between current collector and can, welding between electrode tab and can) through a single measurement approach, reducing inspection complexity while maintaining comprehensive 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 in-line total inspection of welding quality, improving production efficiency by identifying defects quickly and preventing defective batteries from progressing, thus enhancing overall battery quality.
Implementation Method 1
measuring a resistance value by contacting a first probe unit with an upper surface of a first current collector plate and contacting a second probe unit with a lower surface of a second current collector plate
Data Source
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AI summary
The present invention relates to a method for inspecting the weld states of a battery, in which the weld states of a cylindrical battery are inspected, the cylindrical battery comprising: a cylindrical jelly roll in which a first current collector, a first separator, a second current collector, and a second separator are sequentially stacked and wound, so as to extend in the vertical direction; a first collector plate which is coupled to the upper end of the jelly roll, and onto the lower surface of which the first current collector is firstly welded; and a second collector plate which is coupled to the lower end of the jelly roll, and onto the upper surface of which the second current collector is secondly welded. The method for inspecting the weld states of a battery comprises a first measurement step, a second measurement step, a first weld determination step, and a second weld determination step.