Ultrasonic Reflection Coefficient Angular Spectrum for Lithium-Ion Battery SOC
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Solution Overview
Problem
Current methods for determining the State of Charge (SOC) of lithium-ion batteries are inaccurate and computationally intensive, often introducing errors due to variations in acoustic impedance and internal structure changes during charge-discharge cycles, complicating the non-destructive testing of lithium-ion batteries.
Innovation Solution
A method utilizing ultrasonic reflection coefficient angular spectrum analysis, where lithium-ion batteries are discharged and charged in controlled steps, and ultrasonic water immersion detection is used to measure reflection coefficients at varying angles, establishing a mapping relationship between the reflection coefficients and SOC, enabling precise characterization of the battery's charge state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional methods (voltage, impedance, coulomb counting) are used to detect SOC, then the detection can be performed, but the accuracy is insufficient and computational load is high
Solution Approach 1:
The patent replaces traditional electrical measurement methods (voltage, impedance, coulomb counting) with ultrasonic acoustic field-based detection. By transmitting ultrasonic waves through the battery and analyzing reflection coefficients, the system achieves SOC detection without complex computational processing, directly resolving the contradiction between measurement accuracy and computational complexity
Solution Approach 2:
The patent utilizes the change in acoustic impedance parameters of the battery during charge-discharge cycles. As SOC changes, the acoustic properties of the battery materials change, causing measurable variations in ultrasonic reflection coefficients. This physical parameter change provides a direct and accurate indicator of SOC state
2Speed
If ultrasonic detection is used to avoid contact and improve speed, then non-contact high-speed detection is achieved, but the complexity of the detection system increases
Solution Approach 1:
The patent introduces water as an intermediary coupling medium between the ultrasonic transducer and the battery. The water coupling layer facilitates efficient ultrasonic wave transmission into the battery without requiring direct mechanical contact or complex coupling mechanisms, thereby achieving non-contact detection while minimizing system complexity
Solution Approach 2:
The patent segments the ultrasonic detection process into distinct functional components: ultrasonic wave generation, signal reception, reflection coefficient calculation, and SOC determination. This segmentation allows each component to be optimized independently and simplifies the overall system architecture while maintaining high detection speed
3Measurement precision
If the internal structure changes during charge-discharge cycles are considered, then more accurate SOC detection can be achieved, but the acoustic impedance mismatch increases and detection becomes more difficult
Solution Approach 1:
The patent employs feedback by continuously monitoring the ultrasonic reflection coefficients during charge-discharge cycles and using this information to track SOC changes. The system adapts to the changing acoustic impedance conditions by real-time measurement and comparison, maintaining detection accuracy despite internal structural changes
Solution Approach 2:
The patent transitions from traditional single-point electrical measurements to multi-dimensional ultrasonic field analysis. By measuring reflection coefficients at different locations and angles within the battery, the system gains additional dimensional information that helps characterize SOC while compensating for acoustic impedance variations through comprehensive spatial sampling
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides high-speed, non-contact, and accurate detection of lithium-ion battery SOC, leveraging internal property changes to characterize the charge state with reduced computational load and increased precision compared to existing methods.
Implementation Method 1
a wideband ultrasonic probe with a certain central frequency is used to generate and receive signals, thereby capturing the ultrasonic reflection signal from the lithium-ion battery
Implementation Method 2
Using an ultrasonic water immersion detection method, a lithium-ion battery at a specific state of charge obtained from Step 2 is placed into a water tank
Data Source
AI summary
The present invention discloses a method for characterizing the State of Charge (SOC) of lithium-ion batteries using an ultrasonic reflection coefficient, which employs a water immersion ultrasonic detection method for measuring the reflection coefficient angular spectrum of lithium-ion batteries. This invention pertains to the field of non-destructive testing technology. A pouch-type lithium-ion battery can be regarded as a laminated structure composed of multiple materials, and when the State of Charge (SOC) of the lithium-ion battery varies, its reflection coefficient changes accordingly. The invention acquires the reflection coefficient angular spectrum of lithium-ion batteries at different SOCs through ultrasonic water immersion detection, establishes a mapping relationship between the angular spectrum and the SOC of the lithium-ion battery, and uses the distance between the two peak values of the angular spectrum to characterize the SOC of the lithium-ion battery. The invention enables non-destructive characterization of the SOC of lithium-ion batteries and allows for localized SOC measurement of the batteries.