Secondary Battery Lifespan Assessment via Low-Current Voltage Difference
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Solution Overview
Problem
Existing methods for assessing the lifespan of secondary batteries are either time-consuming or inaccurate, failing to provide a reliable and efficient means to determine battery degradation and replacement needs.
Innovation Solution
A method involving primary and secondary aging, degassing, low-current charging and discharging, and voltage difference analysis to accurately assess the lifespan of secondary batteries, using a C-rate of 1/15 C or less to determine battery health within a short time frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional lifespan assessment methods are used, then measurement accuracy is improved, but assessment time increases significantly
Solution Approach 1:
The patent applies preliminary action by performing initial charging to a specific SOC range (30-70%) before the main lifespan assessment measurement. This preliminary charging step prepares the battery in an optimal state for subsequent voltage difference measurement, enabling accurate lifespan assessment without requiring complete charge-discharge cycles, thus reducing total assessment time while maintaining measurement precision.
Solution Approach 2:
The patent extracts only the essential measurement elements needed for lifespan assessment - specifically measuring voltage difference at specific SOC points (such as 30% and 70% SOC) rather than requiring full charge-discharge cycles. This extraction of critical measurement points from the complete charging process significantly reduces assessment time while preserving the accuracy needed to determine battery lifespan.
2Productivity
If fast assessment methods are used, then assessment time is reduced, but measurement accuracy deteriorates
Solution Approach 1:
The patent changes the measurement parameters from traditional full charge-discharge cycle methods to voltage difference measurement at specific SOC points (30-70%). By changing the measurement approach to focus on voltage differences at predetermined charge states rather than complete cycles, the method achieves both faster assessment speed and maintained accuracy through optimized parameter selection.
3Measurement precision
If complete charge-discharge cycles are performed, then lifespan assessment accuracy is improved, but energy consumption increases
Solution Approach 1:
The patent applies partial action by performing only the necessary portion of the charging process - charging to a specific SOC range (30-70%) rather than completing full charge-discharge cycles. This partial charging approach provides sufficient data for accurate lifespan assessment through voltage difference measurement while consuming significantly less energy compared to complete cycling methods.
Data Source
AI summary
A method for predicting a lifespan of a secondary battery within a short time in a more accurate and effective way is provided. The method for assessing a lifespan of a secondary battery includes primarily aging a prepared secondary battery for a predetermined time, initially charging the primarily aged secondary battery to a predetermined SOC and secondarily aging the initially charged secondary battery for a duration greater than the primary aging. Additionally, degassing removes gas in the secondarily aged secondary battery. Further, the method includes charging the secondary battery with a primary low-current at C-rate of 1/15 C or less, after the degassing step, discharging the secondary battery with a primary low-current at C-rate of 1/15 C or less, after the primary low-current charging step and determining a lifespan of the secondary battery by using a difference of voltages measured at different time points.