Battery Insulation Testing Dry State Voltage Determination
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Solution Overview
Problem
Existing methods for inspecting batteries fail to accurately detect electrical short circuits and potential short circuits, leading to incorrect identification of defective products and increased manufacturing costs due to unnecessary waste and inefficiencies.
Innovation Solution
A method involving two withstanding voltage determinations: one between the positive and negative electrode terminals, and another between the electrode terminals and the metallic layers, applied before the electrolyte solution is poured, to assess insulation integrity and potential for short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulation resistance is measured after pouring electrolyte solution in the package, then short circuit detection can be performed in the completed battery state, but the electrolyte solution acts as a current conducting passage and lowers insulation, causing false detection of defective products
Solution Approach 1:
The patent applies withstanding voltage determination before pouring the electrolyte solution into the package. This preliminary inspection is performed on the electrode laminate and package assembly in a dry state, where no conductive electrolyte is present. The first withstanding voltage determination checks insulation between positive and negative electrodes, while the second checks insulation between electrodes and metallic layers of the package. This timing resolves the contradiction by eliminating the electrolyte's interfering conductive effect during measurement.
2Productivity
If only a single voltage test is performed, then the inspection process is simple and quick, but both existing short circuits and potential future short circuits cannot be effectively distinguished
Solution Approach 1:
The patent segments the inspection process into two distinct withstanding voltage determination steps with different voltage levels and test objectives. The first determination uses a lower voltage to check for existing short circuits between electrodes. The second determination uses a higher voltage to stress-test and detect potential future short circuits between electrodes and the metallic package layers. This segmentation allows the system to identify both current defects and latent risks that a single test would miss.
Solution Approach 2:
The patent changes the voltage parameter between the two determination steps. The first withstanding voltage determination applies a lower voltage (e.g., 50V) suitable for detecting existing short circuits without causing damage. The second determination applies a higher voltage (e.g., 200V or more) to create stress conditions that reveal potential insulation weaknesses and future short circuit risks. This parameter variation enables differentiated detection capabilities while maintaining a relatively simple two-step process.
3Reliability
If insulation resistance measurement is performed in the completed battery state, then the battery structure is fully assembled, but defective products are incorrectly identified as non-defective due to the electrolyte solution's conductive properties
Solution Approach 1:
The patent performs the critical insulation resistance measurements before the electrolyte solution is poured into the package. The first withstanding voltage determination tests insulation between positive and negative electrodes, and the second tests insulation between electrodes and metallic package layers. By completing these measurements in the dry state before electrolyte injection, the inspection avoids the false positive problem where conductive electrolyte would mask insulation defects and cause non-defective batteries to be incorrectly rejected.
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 effectively identifies and removes defective products with insulation failures or potential future failures, reducing waste and improving production efficiency and cost-effectiveness by ensuring accurate detection of short circuits before the battery is fully assembled.
Implementation Method 1
a first withstanding voltage determination step of housing the electrode laminate within the package and applying a first voltage between the positive electrode terminal and the negative electrode terminal in a state in which the electrolyte solution is not poured in the package to perform a first withstanding voltage determination; a second withstanding voltage determination step of applying a second voltage which is higher than the first voltage between the positive electrode terminal or the negative electrode terminal and the metallic layer to perform a second withstanding voltage determination in a state in which the electrolyte solution is not poured in the package
Data Source
AI summary
A method for inspecting a battery, comprising: a first withstanding voltage determination step of housing an electrode laminate within a package and applying a first voltage between a positive electrode terminal and a negative electrode terminal to perform a first withstanding voltage determination in a state in which an electrolyte solution is not poured in the package; and a second withstanding voltage determination step of applying a second voltage which is higher than the first voltage between the positive electrode terminal or the negative electrode terminal and metallic layers of pair of laminate films to perform a second withstanding voltage determination in the state in which the electrolyte solution is not poured in the package.