Sealed Battery Leak Testing via Controlled Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing method for manufacturing sealed batteries involves leak testing with helium gas, which results in variable helium gas density due to electrolytic solution penetration, leading to erroneous product determinations as the output values of helium leakage detectors can exceed inspection thresholds, increasing the erroneous determination rate.
Innovation Solution
A method that involves pouring an electrolytic solution into the battery case, reducing the internal pressure to a predetermined level higher than the saturated steam pressure, and introducing detection gas in a quantity corresponding to this pressure, ensuring a consistent helium gas density for accurate leak testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If helium gas is introduced when electrolytic solution is poured into the battery case, then the leak testing can be performed, but the density of helium gas inside the battery case becomes variable due to electrolytic solution penetration, leading to increased erroneous determination rate
Solution Approach 1:
The patent applies preliminary action by reducing the internal pressure of the battery case to a predetermined pressure before introducing the electrolytic solution. This pre-established pressure condition ensures that when helium gas is subsequently introduced, it penetrates consistently through the electrode body regardless of variations in electrolytic solution penetration, thereby maintaining consistent helium gas density and reducing erroneous determinations in leak testing
Solution Approach 2:
The patent changes the pressure parameter by reducing the internal pressure of the battery case to a predetermined pressure (lower than atmospheric pressure) before electrolytic solution introduction. This parameter change creates a controlled pressure differential that ensures consistent helium gas penetration through the electrode body, maintaining uniform helium gas density during leak testing and improving measurement precision
2Reliability
If the inspection threshold is set based on low density of helium gas, then normal products can be accurately identified, but products with high density helium gas may be erroneously determined as defective
Solution Approach 1:
By reducing the internal pressure to a predetermined pressure before introducing both electrolytic solution and helium gas, the patent establishes consistent initial conditions that ensure uniform helium gas distribution. This preliminary pressure control eliminates the variability in helium gas density that causes the inspection threshold to misclassify products, thereby reducing erroneous determinations while maintaining reliable defective product detection
3Ease of manufacture
If helium gas is introduced at atmospheric pressure, then the process is simple, but the density of helium gas varies due to electrolytic solution penetration, reducing leak testing reliability
Solution Approach 1:
The patent changes the pressure parameter from atmospheric pressure to a predetermined reduced pressure before introducing helium gas. This parameter change compensates for the variability caused by electrolytic solution penetration, ensuring consistent helium gas density and reliable leak testing results while adding only a simple pressure control step to the manufacturing process
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 approach reduces the erroneous determination rate in leak testing by maintaining a consistent helium gas density, enhancing the accuracy and robustness of the leak testing process while minimizing the risk of good products being incorrectly identified as defective.
Implementation Method 1
an internal pressure of the battery case into which the electrolytic solution is poured is reduced down to a predetermined pressure
Implementation Method 2
detection gas is introduced into the battery case whose internal pressure is reduced down to the predetermined pressure in a quantity corresponding to the predetermined pressure
Data Source
AI summary
Provided is a method for manufacturing a sealed battery, capable of reducing an erroneous determination rate in a leak testing step. A manufacturing step including a leak testing step for detecting leak of helium gas introduced into an exterior, including a step for pouring an electrolytic solution into the exterior, a step for reducing the pressure inside the exterior down to a predetermined pressure, and a step for introducing the helium gas in a quantity corresponding to the predetermined pressure into the exterior. Preferably, the predetermined pressure is set to a pressure higher than the saturated steam pressure of the electrolyte solution.