Optimization and Application of Electromagnetic Ultrasonic Transducer for Battery Non-Destructive Testing.

Area of Science:

• Materials Science and Engineering
• Electrical Engineering
• Non-Destructive Testing

Background:

• Monitoring the safety and health of lithium-ion batteries (LIBs) is crucial but challenging.
• Conventional ultrasonic testing methods require couplants, limiting their application in battery assessment.
• Non-destructive evaluation (NDE) techniques are needed for reliable internal condition assessment of LIBs.

Purpose of the Study:

• To apply electromagnetic acoustic transducer (EMAT) technology for non-destructive testing of LIBs.
• To design and optimize an EMAT for enhanced ultrasonic wave generation and reception.
• To evaluate the performance of retired LIBs using the developed EMAT system.

Main Methods:

• Independent design of an EMAT utilizing a Halbach magnet array and a butterfly coil.
• Optimization of the EMAT design to maximize received signal amplitude.
• Application of the optimized EMAT for non-contact ultrasonic evaluation of retired 270 Ah LIBs.

Main Results:

• EMAT design optimization resulted in a fourfold increase in received signal amplitude.
• Retired LIBs with capacities below 240 Ah showed signal amplitudes over 40% lower than higher capacity batteries.
• The EMAT system enabled non-contact, disassembly-free performance evaluation.

Conclusions:

• The optimized EMAT technology provides a sensitive and reliable method for assessing LIB internal conditions.
• This non-contact approach is effective for rapid performance evaluation and sorting of retired LIB units.
• EMAT offers a promising solution for LIB safety monitoring and end-of-life management.