Battery Categorization Using Two-Stage Safety and Service Life Evaluation
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Solution Overview
Problem
Current methods for categorizing batteries for further handling do not effectively separate safety and service life considerations, leading to inaccurate evaluations and inadequate determination of their suitability for reuse or recycling.
Innovation Solution
A two-stage evaluation method that records safety-relevant and service life-relevant operating variables for batteries, using Shannon entropy and Weibull distribution to derive a categorization variable, prioritizing safety over service life and determining a recycling category based on threshold values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single-stage evaluation method is used to categorize batteries, then the evaluation process is simple, but the categorization accuracy is insufficient because safety and service life considerations are not effectively separated
Solution Approach 1:
The evaluation process is divided into two distinct stages: a first stage that evaluates safety-relevant operating parameters (voltage, temperature, current) and a second stage that evaluates service life-relevant parameters (cycle count, capacity degradation). This segmentation allows safety and service life considerations to be separately assessed and combined, improving categorization accuracy while maintaining manageable process complexity through structured progression.
2Reliability
If safety and service life parameters are combined in a single evaluation, then the evaluation process is simple, but the reliability of categorization is reduced due to inaccurate evaluations
Solution Approach 1:
The evaluation system is segmented into two independent evaluation streams: one dedicated to safety parameters (voltage, temperature, current) and another to service life parameters (cycle count, capacity degradation). Each stream processes its parameters independently through respective evaluation functions, then combines results to determine the final categorization. This segmentation enhances reliability by preventing safety issues from being masked by service life considerations, while the modular structure keeps system complexity manageable.
Solution Approach 2:
Different evaluation criteria and threshold values are applied locally to different parameter types. Safety parameters use immediate threshold-based evaluation with strict limits, while service life parameters use progressive degradation models. This local differentiation ensures each parameter type is evaluated with appropriate criteria, improving overall categorization reliability.
3Measurement precision
If detailed two-stage evaluation is implemented, then categorization accuracy is improved, but the complexity of the evaluation system increases
Solution Approach 1:
The system segments evaluation into two sequential stages with clear boundaries. Stage 1 processes safety parameters through immediate threshold comparison, producing a safety assessment. Stage 2 processes service life parameters through degradation modeling, producing a service life assessment. The final categorization combines both assessments. This segmentation achieves high precision while controlling complexity through structured modularity and clear separation of concerns.
Solution Approach 2:
The system performs preliminary evaluation of safety parameters in the first stage before proceeding to service life evaluation in the second stage. This preliminary action allows early identification of safety issues and structures the subsequent service life evaluation based on safety assessment results, improving overall precision while managing complexity through staged processing.
Data Source
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AI summary
To categorize a battery (1) with regard to its suitability for further handling, a multitude of safety-relevant and service life-relevant operating parameters are recorded for at least one battery cell (4) of the battery (1) according to a specific procedure. A categorization parameter (SoR) is then determined by means of a two-stage evaluation of at least one of the operating parameters and/or a calculated parameter derived therefrom. In a first stage, a safety parameter is derived for at least one safety-relevant operating parameter and compared with an associated threshold value. If the threshold value, or one of the potentially multiple threshold values, is undershot, a failure prediction is generated in a second stage using a plurality of the service life-relevant operating parameters. The categorization parameter (SoR) is then determined based on the failure prediction.