Lithium ion battery bubble defect detection method based on ultrasonic detection technology

Abstract

The invention discloses a lithium ion battery bubble defect detection method based on ultrasonic detection technology, and belongs to the technical field of the ultrasonic non-destructive detection. The detection method comprises the following steps: selecting an air coupling ultrasonic energy converted with high frequency by adopting an air coupling vertical penetration method; measuring and computing energy converter axis sound pressure distribution, and defining the distance between the energy converter and a sample by adopting a -6dB method; arranging a location of the energy converter; setting parameters of a function emitter, a power amplifier and a pre-amplifier; jointly processing an amplitude value and a signal-to-noise ratio of a transmission signal by adopting the pulse compression wavelet de-noising; adjusting the sensitivity of the signal, scanning and saving A-scanning data and C-scanning data; quantifying the size of the bubble type defect by adopting the -6dB sensitivity method, and estimating the diameter of the defect; rejecting the lithium ion battery with the defect diameter greater than the threshold, and finally guaranteeing the security of the service environment. The air-coupling ultrasonic detection on the bubble type defect of the lithium ion battery can be realized, and the detection result is accurate.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic nondestructive testing, and in particular relates to an air-coupled ultrasonic technology, in particular to an air-coupled ultrasonic detection method for detecting bubble defects in lithium-ion batteries based on ultrasonic detection technology. Background technique [0002] High-performance lithium-ion batteries are considered to be the most promising high-efficiency power sources due to their high energy density, high operating voltage, low self-discharge rate, long cycle life, no memory effect, and environmental protection. In recent years, lithium-ion batteries have been widely used in aerospace, national defense and military, energy transportation and other fields. Within 5-10 years, lithium-ion batteries will gradually replace nickel-cadmium and nickel-hydrogen batteries and become the mainstream energy storage power source in various fields at home and abroad. However, the safety and r...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a non-contact air-coupled ultrasonic detection method for bubble-like defects generated during the preparation or service of lithium-ion batteries, and to standardize the selection of process parameters in the detection, so as to solve the problem of weak air-coupled ultrasonic transmission signals and signal-to-noise problems. Ratio difference and other issues, and finally realize the air-coupled ultrasonic detection of bubble defects in lithium-ion batteries, and provide technical support for the industrial detection of bubble defects in lithium-ion batteries

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