Battery Cell Short-Circuit Inspection via Jig Pressurization
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Solution Overview
Problem
Existing methods for inspecting secondary battery cells for low voltage failures due to separator defects are inefficient, particularly in detecting defects in a large number of cells quickly and accurately, and often require additional equipment, which can slow down production.
Innovation Solution
A pressure short circuit inspection method using a jig pressurization scheme that involves pre-aging battery cells, applying a constant voltage, and measuring leakage current to detect separator defects such as tearing, folding, or puncture, allowing for rapid identification of defective cells without the need for additional equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If vision inspection is used to detect assembly defects, then the inspection process is simple, but defects in stack-folding type battery cells cannot be easily distinguished
Solution Approach 1:
The patent replaces vision inspection (optical system) with a pressurization-based electrical inspection system. By applying pressure to the battery cell and measuring electrical properties, the system can detect internal defects such as separator damage that are invisible to optical inspection, thereby improving measurement precision while maintaining operational simplicity.
Solution Approach 2:
The patent changes the inspection parameter from optical visualization to electrical measurement under pressurization. By applying mechanical pressure and measuring electrical resistance or current leakage, the system transforms the detection method to reveal internal structural defects that cannot be observed visually, thus improving defect detection accuracy.
2Device complexity
If a Chinese character-shaped jig is used for HI-POT test, then the device is simple, but the pressure is not enough to generate short circuit at separator defect portions
Solution Approach 1:
The patent modifies the pressurization parameter by increasing the pressure magnitude and duration applied during inspection. The improved jig applies sufficient pressure to force contact between electrodes at separator defect locations, enabling reliable short circuit detection while maintaining the simplicity of the jig-based approach.
Solution Approach 2:
The patent applies pressurization before the HI-POT test to pre-compress the battery cell and force electrode contact at potential defect sites. This preliminary mechanical action ensures that subsequent electrical testing occurs under conditions that maximize defect detection reliability.
3Strength
If pressurization is applied to uncharged battery cells, then the mechanical stiffness is high, but it is difficult to contact the interface between positive and negative electrodes
Solution Approach 1:
The patent applies a preliminary charging step before pressurization. By charging the battery cell first, the electrodes expand and become more compliant, reducing mechanical stiffness. This preliminary action enables subsequent pressurization to effectively contact the electrode interfaces at separator defect locations for reliable detection.
4Quantity of substance
If inspection is performed on a large number of battery cells, then production volume is high, but inspection time increases
Solution Approach 1:
The patent combines multiple inspection functions into a single integrated pressurization-and-measurement step. By merging the mechanical pressurization and electrical measurement into one simultaneous operation, the system achieves rapid inspection that can be scaled to handle large numbers of cells without proportionally increasing inspection time.
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 enables the rapid detection of low voltage failures in battery cells within seconds to tens of seconds, improving production efficiency and accuracy in identifying minute separator defects, while utilizing existing activation jigs to inspect multiple cells simultaneously without disrupting production.
Implementation Method 1
it is necessary to internal-short-circuit the portion by pressurizing the portion to recognize the defect
Implementation Method 2
pressurizing the portion to recognize the defect
Implementation Method 3
a method of detecting a low voltage through a HI-POT test while pressing the body portion of the cell
Data Source
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AI summary
A jig pressing-type pressing short-circuiting inspection method of the present invention comprises the steps of: pre-aging battery cells, each of which is manufactured by inserting an electrode assembly in a battery container, injecting an electrolyte into the battery container, and sealing the battery container, the electrode assembly including a positive electrode, a negative electrode, and a separation film laminated on each other, the separation film being disposed between the positive electrode and the negative electrode (S100); inserting the plurality of battery cells in an active jig (S200); pressing the active jig (S300); and inspecting electric current of the battery cells (S400). The pressing short-circuiting inspection method according to the present invention enables inspection of a low-voltage defect of a battery cell in a pre-aging state, which shows a high voltage regulation per capacity, and thus can greatly reduce the inspection time. In addition, the present invention enables a micro-defect occurring in a stack-folding type battery cell, which is difficult to be detected by the conventional inspection method, to be accurately detected, and enables simultaneous inspection of a plurality of battery cells by using an active jig.