Battery Separator DMA Screening for Explosion Safety Prediction
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Solution Overview
Problem
Conventional methods for evaluating the stability of secondary battery separators against explosion are time-consuming and costly, requiring the assembly of actual batteries, and there is a need for a rapid and simple method to predict safety against explosion.
Innovation Solution
A method using dynamic mechanical analysis (DMA) to determine the elongation properties of separators, such as breaking temperature and shrinkage, and comparing these properties to defined stability standards, which are then validated through a nail penetration test, allowing for the classification of separators as stability-passing or failing, thereby predicting their safety against explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods are used to evaluate separator stability by assembling actual batteries, then accurate safety evaluation is achieved, but significant time and cost are required
Solution Approach 1:
The patent uses dynamic mechanical analysis to measure elongation properties of the separator as a simplified copy or proxy for the actual battery safety test. Instead of assembling complete batteries for testing, the separator itself is tested under controlled conditions that replicate the critical failure mode (thermal runaway), providing accurate safety evaluation without the time and resource costs of full battery assembly and testing
Solution Approach 2:
The patent extracts the critical safety evaluation function from the complete battery system and isolates it to just the separator component. By taking out the separator from the complex battery assembly and testing it independently through DMA, the method achieves accurate safety prediction while eliminating the time-consuming steps of battery assembly and full-system testing
2Reliability
If conventional methods are used to evaluate separator stability by assembling actual batteries, then reliable safety prediction is achieved, but high cost is incurred
Solution Approach 1:
The patent creates a simplified test copy using only the separator material subjected to dynamic mechanical analysis, rather than requiring complete battery assembly. This copying approach maintains reliable safety prediction by focusing on the separator's critical thermal and mechanical properties, while dramatically reducing the cost associated with battery materials, assembly labor, and testing infrastructure
3Productivity
If simple evaluation methods are used for separator properties, then rapid evaluation is achieved, but prediction accuracy for explosion safety may be insufficient
Solution Approach 1:
The patent changes the measurement parameters from simple physical dimensions to dynamic mechanical properties including elongation at break, breaking load, and thermal behavior under stress. These parameter changes enable rapid evaluation through DMA while maintaining high prediction accuracy for explosion safety, as the measured parameters directly correlate with the separator's ability to prevent thermal runaway
Solution Approach 2:
The patent replaces complex electrochemical battery testing with a purely mechanical and thermal analysis system (DMA). This substitution achieves rapid evaluation by eliminating electrochemical charging/discharging cycles and instead using mechanical deformation and thermal stress tests that directly reveal the separator's safety-critical properties with high precision
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 method allows for the rapid and accurate prediction of separator stability, eliminating the need for assembling secondary batteries and providing results matched with nail penetration tests, thus ensuring safety against explosion by selecting separators with excellent safety properties.
Implementation Method 1
determining the elongation properties of the separator by using dynamic mechanical analysis (DMA)
Data Source
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AI summary
Disclosed is a method for evaluating the stability of a separator, including the steps of: preparing a separator; determining the elongation properties of the separator by using dynamic mechanical analysis (DMA); comparing the determined value with the stability standards of the elongation properties; and classifying a separator as a stability-passing separator when the determined values satisfy the stability standards, and classifying a separator as a stability-failing separator when the determined values do not satisfy the stability standards, after the comparison.