Air-Coupled Ultrasonic Electrode Scanning for Density and Defect Mapping
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Solution Overview
Problem
Conventional non-destructive evaluation methods for battery electrodes, such as ultrasound, require liquid couplants, limiting their application to enclosed batteries and failing to detect buried defects or local density variations in thin film electrodes during manufacturing.
Innovation Solution
An air-coupled ultrasonic scanning platform using piezocomposite transducers operates at high frequencies, enabling non-contact, non-destructive measurement of electrode density and thickness, detecting defects during casting and drying by mapping local variations through air coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ultrasonic testing is used with liquid couplant, then sound wave transmission efficiency is improved, but application is limited to enclosed batteries and cannot detect defects in thin film electrodes during manufacturing
Solution Approach 1:
The patent introduces air as an intermediary medium between the ultrasonic transducer and the electrode, replacing the traditional liquid couplant. This allows non-contact ultrasonic testing of thin film electrodes during manufacturing while maintaining sufficient sound wave transmission for defect detection
Solution Approach 2:
The patent extracts the liquid couplant from the testing system and replaces it with air coupling. This removal enables the system to test thin film electrodes in their native manufacturing environment without requiring immersion or contact with coupling fluids
2Productivity
If optical cameras and laser thickness gauges are used for quality checking, then visual defects can be detected, but buried defects and local density variations cannot be detected
Solution Approach 1:
The patent replaces optical detection methods with ultrasonic wave-based detection. Ultrasonic waves can penetrate the electrode material and detect buried defects and density variations that are invisible to optical methods, while maintaining rapid inspection capability
Solution Approach 2:
The patent uses ultrasonic wave properties (amplitude, time, frequency) as analogs to optical properties. By analyzing changes in these ultrasonic parameters as waves pass through the electrode, the system can detect variations in density and structure that optical methods miss
3Measurement precision
If X-rays and spectroscopic imaging tools are used for high-resolution defect detection, then measurement precision is improved, but ex situ sampling is required and testing becomes time- and cost-intensive
Solution Approach 1:
The patent enables the electrode to be tested in its own manufacturing environment without requiring removal for ex situ analysis. The air-coupled ultrasonic system can inspect electrodes directly on the production line, eliminating the time and cost associated with sample preparation and specialized imaging equipment
4Measurement precision
If contact-mode transducers are used for ultrasonic testing, then measurement precision is improved, but the method requires liquid or solid couplant which limits application to enclosed batteries
Solution Approach 1:
The patent removes the liquid or solid couplant requirement from the ultrasonic testing system by using air coupling. This simplifies operation by eliminating the need for couplant application and enables testing of thin film electrodes in their native manufacturing environment
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
The platform effectively identifies homogeneous regions, detects defects, and ensures quality control in battery electrode manufacturing by providing data-rich, rapid, and accurate assessments of density and thickness, reducing product waste and enhancing safety.
Implementation Method 1
An air-coupled ultrasonic scanning platform using piezocomposite transducers operates at high frequencies, enabling non-contact, non-destructive measurement of electrode density and thickness
Implementation Method 2
piezocomposite transducers
Implementation Method 3
detecting defects during casting and drying by mapping local variations through air coupling
Implementation Method 4
which can be further processed to obtain data about electrode density, defects, and mechanical properties
Data Source
AI summary
An air-coupled ultrasonic scanning platform for an air-coupled ultrasonic non-contact metrology of battery electrodes that maps the local variation in density and thickness, and detect defects during electrode casting and drying, includes: piezocomposite air-coupled transducers (Ultran) at 0.5 to 1 MHz that provide sufficient air coupling to enable sound waves to travel through air from a transmitting transducer, through the thin film electrode coated on metal current collector, and then into the receiving transducer. Non-contact, air-coupled ultrasound may be used as a technique for evaluating battery electrode films. An analytical model was derived from fundamental acoustic wave propagation principles to determine acoustic density. Voltage gain or acoustic density maps of electrode films revealed features that are not visually apparent, attributed to mass gradients.