Leak Testing Sealed Battery Cells Using Vacuum and Acceleration
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Solution Overview
Problem
Current leak testing methods for batteries are inefficient as they require unfinished cells, additional tracer gases, or lengthy cycles, and are not compatible with industrial processes, especially for sealed lithium-ion batteries.
Innovation Solution
A method and system for leak testing finished and sealed battery cells by detecting gases and vapors already present or generated inside the cell without additional tracer gases, using a vacuum chamber and mass spectrometer, with heating components to prevent residue deposition and increasing pressure to enhance detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional tracer gas (helium) is inserted into the cell for leak testing, then leak detection capability is improved, but device complexity and manufacturing process complexity increase
Solution Approach 1:
The invention extracts and eliminates the need for additional tracer gas from the leak testing process. Instead of inserting helium or other tracer gases into the cell, the method uses the cell's existing internal atmosphere (air or inert gas already present during manufacturing) as the test medium. This simplifies the manufacturing process by removing the complex steps of gas insertion, sealing, and subsequent tracer gas detection equipment.
Solution Approach 2:
The invention makes the cell's existing internal atmosphere serve the dual purpose of both cell operation and leak testing. The gas already present in the cell (air or inert gas from manufacturing) is utilized for leak detection without requiring any additional substances. This self-service approach eliminates the need for separate tracer gas systems and simplifies the overall testing process.
2Ease of operation
If leak testing is performed on unfinished cells before sealing, then leak detection is simplified, but testing reliability decreases because it cannot detect leaks in the sealed structure
Solution Approach 1:
The invention performs preliminary leak testing on the cell structure before final sealing, using the existing internal atmosphere. The method is designed to work with unfinished cells that have not yet been hermetically sealed, allowing leak detection to be integrated into the manufacturing process flow before the cell becomes completely sealed and harder to test.
Solution Approach 2:
The invention creates a universal leak testing method that can detect leaks in both sealed and unsealed cells using the same approach. By using the cell's existing internal atmosphere rather than requiring tracer gas, the method becomes applicable to cells at various stages of manufacturing, including finished sealed cells, without requiring different testing procedures for different cell states.
3Measurement precision
If the cell is placed in a vacuum chamber for leak testing, then leak detection sensitivity is improved, but cycle time increases
Solution Approach 1:
The invention applies partial vacuum (reduced pressure) rather than complete high vacuum to achieve sufficient leak detection sensitivity. By using moderate vacuum levels, the method achieves adequate sensitivity to detect leaks while significantly reducing the time required to establish the test environment and complete the measurement, thus shortening the overall cycle 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
Enables reliable and repeatable leak rate measurement in sealed battery cells, reducing cycle time and preventing contamination, making it compatible with industrial processes and ensuring accurate detection of leaks.
Implementation Method 1
a vacuum pump (6) to create a vacuum inside said chamber (4)
Implementation Method 2
a detecting and measuring instrument (1), in this case a mass spectrometer, to detect said gases and/or vapors
Implementation Method 3
a heating device (7) to heat at least one component of said system (100)
Data Source
AI summary
Method for leak testing a finished battery cell using a leak test system comprising a vacuum chamber and a detecting and measuring instrument, the method including positioning the cell in the vacuum chamber, sealing the vacuum chamber, starting a vacuum creation phase in which the pressure inside the vacuum chamber is decreased, starting a stabilization phase in which gases and/or vapors deriving from parts and/or substances inside the cell leak from the cell, starting an acceleration phase in which an auxiliary gas is fed into the vacuum chamber pushing the gases and/or vapors leaking from the cell towards the detecting and measuring instrument, and detecting the leak rate by means of the detecting and measuring instrument. In the acceleration phase the pressure inside the leak test system is raised, thereby increasing the flow of the gases and/or vapors leaking from the cell towards the detecting and measuring instrument.