Optical Unit Cell Thickness Measurement for Moving Battery Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring the thickness of unit cells in secondary battery electrode assemblies are inefficient, particularly in high-speed production environments, as they often require physical contact and are unable to continuously monitor unit cells as they move, leading to difficulties in identifying defective cells before they cause assembly failures.
Innovation Solution
A non-contact thickness measurement method using light-emitting sensors that measure the distance between the top and bottom surfaces of moving unit cells, allowing for real-time calculation of thickness and identification of defects, while also measuring the distance between neighboring cells to optimize assembly processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If physical contact measurement method is used to measure unit cell thickness, then measurement can be performed, but it cannot keep up with high-speed production and cannot measure moving unit cells continuously
Solution Approach 1:
The patent replaces the mechanical contact measurement system with an optical measurement system. Light-emitting units irradiate light onto the unit cells, and light-receiving units detect the reflected or transmitted light to calculate thickness. This substitution eliminates the need for physical contact, enabling continuous measurement of moving unit cells at high production speeds while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces light as an intermediary medium between the measurement system and the unit cells. Instead of direct mechanical contact, light serves as the mediator to transmit measurement information from the unit cells to the sensors, enabling non-contact, continuous measurement during high-speed production.
2Measurement precision
If sample inspection method is used to measure thickness after collecting unit cell samples, then thickness can be measured, but it is difficult to select only defective products and cannot identify defects in real-time
Solution Approach 1:
The patent performs thickness measurement of unit cells immediately after the laminating process, before the unit cells are fully assembled into the electrode assembly. This preliminary measurement allows defective unit cells to be identified and removed early in the production process, preventing defects from propagating to the final product and reducing waste.
Solution Approach 2:
The patent implements continuous thickness measurement of unit cells as they move through the production line, rather than intermittent sampling. The optical measurement system continuously irradiates and detects light from passing unit cells, enabling real-time defect identification and continuous process control.
3Productivity
If unit cells are stacked to form electrode assembly, then electrode assembly can be manufactured, but a single defective unit cell causes the entire assembly to be defective
Solution Approach 1:
The patent performs quality inspection of unit cells before they are stacked into the electrode assembly. By measuring the thickness of each unit cell immediately after lamination and before assembly, defective unit cells can be identified and removed in advance, ensuring that only合格 unit cells are stacked, thus preventing single-point failures from compromising the entire assembly.
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 continuous, accurate measurement of unit cell thicknesses in real-time, reducing assembly failure rates and improving the efficiency of the subsequent process by quickly identifying and sorting out defective cells, and maintaining accuracy despite external factors like heat and moisture.
Implementation Method 1
irradiating light to a top surface of the unit cell through an upper thickness sensor and irradiating light to a bottom surface of the unit cell through a lower thickness sensor to calculate a time when receiving the reflected light, thereby measuring a distance between the upper thickness sensor and the top surface of the unit cell and a distance between the lower thickness sensor and the bottom surface of the unit cell
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus for measuring a thickness of a unit cell according to the present invention comprises: a plurality of transfer rollers configured to sequentially transfer unit cells and disposed to be spaced a predetermined distance from each other; and a thickness sensor disposed at a fixed position to irradiate light to a moving path of the unit cells and calculate a time when receiving the reflected light, thereby measuring a thickness of each of the unit cells. A method for measuring a thickness of a unit cell according to the present invention comprises: a unit cell transferring step (S1) of transferring unit cells through a plurality of transfer rollers which are spaced a predetermined distance from each other; a distance measuring step (S2) of irradiating light to a top surface of the unit cell through an upper thickness sensor and irradiating light to a bottom surface of the unit cell through a lower thickness sensor to calculate a time when receiving the reflected light, thereby measuring a distance between the upper thickness sensor and the top surface of the unit cell and a distance between the lower thickness sensor and the bottom surface of the unit cell; and a thickness calculating step (S3) of subtracting a measured value of the distance between the upper thickness sensor and the top surface of the unit cell and a measured value of the distance between the lower thickness sensor and the bottom surface of the unit cell from a distance between the upper thickness sensor and the lower thickness sensor to calculate the thickness of the unit cell.