Battery Unit Cell Stack Tilt Inspection for Early Defect Detection
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Solution Overview
Problem
Existing defect detection methods for secondary battery unit cells, such as the Hi-pot process, fail to identify defects accurately, leading to significant losses when defective cells are manufactured as secondary batteries.
Innovation Solution
A defect inspection device and method utilizing a tilt measurement system to assess the stack of unit cells, combined with a discriminator to determine defects based on tilt measurements, and optionally incorporating 3D scanning for precise defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the Hi-pot process is used to detect defects, then the inspection process is simple, but defects in unit cells cannot be detected accurately
Solution Approach 1:
The inspection system is segmented into multiple independent measurement components: tilt measurement means for detecting stack tilt, 3D scan detector for surface topology, and foreign substance detector for contamination. Each component performs a specific measurement function, collectively achieving comprehensive defect detection with high precision while maintaining modular simplicity
Solution Approach 2:
A measuring plate is introduced as an intermediary element between the stack and the measurement system. The plate provides a standardized reference surface that enables accurate tilt and 3D measurements, acting as a mediator that translates physical stack characteristics into measurable data without requiring direct complex contact between sensors and the stack
2Quantity of substance
If the electrode current collector thickness is decreased to achieve compactness, then the battery capacity increases, but defects such as kinks and bends occur more frequently
Solution Approach 1:
The inspection system performs measurements on the stack before final battery assembly. By detecting kinks, bends, and other defects in the unit cells while they are still in stack form, the system enables preliminary identification and removal of defective cells before they are integrated into the final battery product, preventing defect propagation
Solution Approach 2:
The measurement approach transitions from two-dimensional visual inspection to three-dimensional topological measurement. The 3D scan detector captures surface topology data, enabling detection of subtle deformations like kinks and bends that would be invisible in 2D views, thereby improving defect detection capability for thin electrodes
3Productivity
If defective unit cells are not detected, then production continues without interruption, but significant losses occur when defects are manufactured into secondary batteries
Solution Approach 1:
The inspection system enables the production line to self-diagnose and identify defective units automatically. By integrating tilt measurement, 3D scanning, and foreign substance detection capabilities directly into the production flow, the system provides self-service quality control that continuously monitors and flags defective cells without requiring external manual inspection
Solution Approach 2:
The system establishes a feedback loop where measurement data from the stack is immediately analyzed and used to identify defective unit cells. This real-time feedback mechanism allows for immediate detection and removal of defective cells, preventing them from proceeding to subsequent manufacturing stages and causing losses
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 early detection of defects in unit cells, reducing losses by identifying kinks and bends with high precision, thereby improving the quality of secondary battery production.
Implementation Method 1
a tilt measurement means that measures the tilt of the uppermost surface of the stack stacked in the stacked portion
Data Source
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AI summary
The present disclosure relates to a defect inspection device and a defect inspection method, and the defect inspection device according to the present disclosure includes a stacked portion in which a plurality of unit cells including at least one electrode and at least one separator are stacked to form a stack, a tilt measurement means that measures the tilt of the uppermost surface of the stack stacked in the stacked portion, and a discriminator that determines whether the unit cell is defective based on the tilt measurement value measured by the tilt measurement means.