Battery Life Estimation Using Differential Capacity Peaks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The accuracy of determining the cycle life of lithium-ion batteries is compromised due to abnormal lithium precipitation, leading to inaccuracies in capacity retention rate estimation based on a linear relationship.
Innovation Solution
A method involving charge-discharge cycles to determine differential capacity curves and capacity fade values, with linear fitting to establish relationships between differential capacity peaks and cycle numbers, and capacity fade values, allowing for accurate determination of battery life by identifying a capacity fade threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a linear relationship between capacity retention rate and battery cycle number is used to determine cycle life, then the determination process is simple, but the accuracy of battery life determination deteriorates due to abnormal lithium precipitation
Solution Approach 1:
The patent segments the determination process into two distinct linear relationships: one between differential capacity peaks and cycle numbers, and another between capacity fade values and cycle numbers. This segmentation allows the method to account for abnormal lithium precipitation by monitoring deviations in differential capacity peaks while maintaining the simplicity of linear relationships for life prediction.
Solution Approach 2:
The patent introduces differential capacity curves as an intermediary tool to detect abnormal lithium precipitation. By analyzing the differential capacity peaks as a mediator between the simple linear model and the complex battery degradation phenomena, the method maintains computational simplicity while improving accuracy through the additional diagnostic information provided by the intermediary measurement.
2Measurement precision
If abnormal lithium precipitation is accounted for in battery life determination, then the accuracy of battery life determination improves, but the determination process becomes more complex
Solution Approach 1:
The patent divides the complex problem of accounting for lithium precipitation into two separate linear relationships: differential capacity peaks vs. cycle numbers, and capacity fade values vs. cycle numbers. This segmentation reduces complexity by maintaining linearity in both relationships rather than attempting a single complex non-linear model.
Solution Approach 2:
The patent changes the parameters used for determination from a single capacity retention rate to two parameters: differential capacity peaks and capacity fade values. This parameter transformation allows the method to capture lithium precipitation effects while maintaining linear relationships, thus improving accuracy without proportionally increasing complexity.
3Measurement precision
If differential capacity curves and capacity fade values are determined through charge-discharge cycles, then the accuracy of battery life determination improves, but the time required for the determination process increases
Solution Approach 1:
The patent performs charge-discharge cycles at partial capacity levels to obtain differential capacity curves and capacity fade values, rather than requiring complete capacity degradation. This partial action approach provides sufficient data for accurate life determination without needing to run the battery through its entire life cycle, thus reducing the time required while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary charge-discharge cycles to establish the linear relationships between differential capacity peaks, capacity fade values, and cycle numbers before final life determination. This preliminary action allows the method to create predictive models from limited initial data, reducing the total time required for complete battery life testing while maintaining accuracy.
Data Source
AI summary
The present disclosure provides a method and an apparatus for determining life of battery, an electronic device, and a storage medium. The method includes a first linear determination process and a life determination process, performing a charge-discharge cycle on a battery to be tested for a first cycle number; determining differential capacity curves and capacity fade values of the battery to be tested under different preset cycle numbers; and determining, when the differential capacity peaks and the corresponding preset cycle numbers satisfy the first linear relationship, and the capacity fade values and the corresponding preset cycle numbers satisfy the second linear relationship, a cycle number corresponding to a capacity fade threshold of the battery to be tested based on the second linear relationship, determining the cycle number corresponding to the capacity fade threshold of the battery to be tested as a life of the battery to be tested.