Si-Anode Battery SOC Estimation Under Transient Voltage Shifts
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Solution Overview
Problem
The accuracy of estimating the charge state of energy storage devices using Si-based negative active materials is decreased due to transient potential changes caused by specific charge-discharge conditions, leading to inaccurate SOC-OCV correlations.
Innovation Solution
An estimation device that determines whether to perform a first estimation method based on charge-discharge history, using an SOC-OCV curve only when transient potential changes are not present, and switches to a current integration method when they are, thereby improving estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the SOC-OCV curve method is used for estimating charge state in Si-based energy storage devices, then the estimation process is simple, but the estimation accuracy deteriorates due to transient potential changes
Solution Approach 1:
The patent implements a dynamic estimation approach that adapts the estimation method based on real-time charge-discharge conditions. The control unit monitors charge-discharge history and dynamically switches between SOC-OCV curve method and current integration method, making the estimation system flexible and condition-dependent rather than static
Solution Approach 2:
The patent changes the estimation parameters based on charge-discharge history. When transient potential changes are detected through charge-discharge history analysis, the system switches from using voltage-based parameters (SOC-OCV curve) to current-based parameters (current integration method), thereby adapting to different operational states
2Measurement precision
If the current integration method is always used for Si-based energy storage devices, then the estimation accuracy is maintained, but the device complexity increases
Solution Approach 1:
The patent segments the estimation process into two distinct methods: SOC-OCV curve method for normal conditions and current integration method for conditions with transient potential changes. This segmentation allows each method to be optimized for its specific use case while reducing overall system complexity through conditional application
Solution Approach 2:
The system dynamically selects the appropriate estimation method based on charge-discharge history analysis. The control unit implements conditional logic that activates the simpler SOC-OCV curve method when applicable, and only resorts to the more complex current integration method when transient potential changes are detected, thereby optimizing the balance between accuracy and complexity
Data Source
AI summary
An estimation device is a device that estimates a charge state of an energy storage device including a negative electrode having a negative active material that contains Si. The estimation device includes a control unit that determines based on a charge-discharge history of the energy storage device whether or not to perform a first estimation method of estimating a charge state of the energy storage device by using a relationship between the charge state and a voltage of the energy storage device.