Battery SOH Estimation via No-Load Voltage Modeling
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Solution Overview
Problem
Current methods for estimating the state of health (SOH) of batteries are either invasive, time-consuming, or unreliable, as they either require direct capacity tests that disrupt normal usage or rely on indirect parameter monitoring that doesn't accurately reflect capacity loss.
Innovation Solution
A method involving measurements of no-load voltage values at different states of charge, calculation of mathematical model parameters for electrode potentials, and iterative correction to estimate battery capacity and SOH, allowing for non-intrusive and rapid assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacity test is implemented to measure the real value of SOH, then measurement precision is improved, but loss of time and ease of operation deteriorate
Solution Approach 1:
The patent replaces the mechanical/electrical capacity test system with a mathematical modeling system. Instead of physically discharging the battery to measure capacity, the system uses mathematical models that correlate impedance parameters with capacity loss, substituting physical measurement with computational calculation to achieve rapid SOH estimation without time-consuming tests
Solution Approach 2:
The patent introduces impedance parameters as an intermediary between battery aging and capacity loss. Rather than directly measuring capacity through discharge tests, the system measures impedance (an intermediate parameter) and uses mathematical models to infer capacity loss from impedance evolution, enabling indirect but rapid SOH assessment
2Ease of operation
If impedance parameters are monitored to estimate SOH, then ease of operation is improved, but measurement precision deteriorates
Solution Approach 1:
The patent transforms the relationship between impedance and SOH estimation by changing from direct impedance monitoring to using impedance as input for mathematical models. The system changes the parameter relationship by incorporating impedance evolution into predictive models that account for non-linear aging behaviors, improving precision while maintaining ease of operation
Solution Approach 2:
The patent implements feedback mechanisms where impedance measurements are continuously fed into mathematical models that update SOH estimates. The system uses feedback from impedance evolution patterns to refine capacity loss predictions, improving measurement precision through iterative model adjustment while maintaining operational simplicity
3Device complexity
If impedance monitoring is used for SOH estimation, then device complexity is reduced, but reliability deteriorates
Solution Approach 1:
The patent changes the mathematical parameters and relationships used in modeling to improve reliability. By developing refined mathematical models that better capture the non-linear relationship between impedance and capacity loss across different aging conditions, the system achieves higher reliability in SOH estimation while keeping the overall device complexity manageable through software-based solutions
Data Source
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AI summary
Method of estimating the state of health SOH of a battery, characterized in that it comprises the following steps: - measurements (E1) of several values of no-load voltage of the battery for different states of charge; - calculation of parameters (E2) of mathematical models of the no-load potentials of each of the electrodes of the battery, to obtain an estimation of the no-load voltages of the battery for the states of charge considered in the previous step on the basis of these mathematical models; calculation of the state of health SOH (E3) of the battery on the basis of the models of the no-load potentials of each of the electrodes of the battery and parameters associated with these models calculated in the previous step.