A method for three-dimensional imaging of dendrites in lithium metal batteries using photoacoustic imaging

Abstract

The invention discloses a method for realizing three-dimensional imaging of dendrites in a lithium metal battery by using photoacoustic imaging. The sample preparation includes: cutting out a part with a flat cross-section on a symmetrical battery sample, and its side is a photoacoustic imaging observation surface ;Cut off a corner of the negative electrode lithium sheet to mark the relative position of the sample; put it into the stainless steel button battery case for electrochemical testing, and use the set current intensity for charging test; after charging is completed, disassemble the stainless steel button battery case and take out The battery sample is ready for sample preparation; image acquisition includes: placing the sample on the sample platform and fixing it; adjusting the height of the sample and observing the ultrasonic signal intensity to ensure that the sample falls on the focal plane of the laser; two-dimensional scanning of the sample . The invention uses photoacoustic imaging to realize three-dimensional imaging of dendrites in lithium metal batteries, has a large penetration depth, and can directly observe metal features even in the separator, and has the advantages of low cost and easy operation.

Description

technical field [0001] The invention relates to the technical field of dendrite imaging in metal batteries, in particular to a three-dimensional imaging method for realizing dendrites in lithium metal batteries by using photoacoustic imaging. Background technique [0002] A quantitative understanding of Li metal dendrite growth in both conventional liquid electrolytes and current solid-state electrolytes, and the exploration of conditions that can achieve smooth Li deposition with a thickness of tens of micrometers are extremely important. Imaging techniques have proven to be powerful tools for studying dendrite growth. For example, scanning and transmission electron microscopy have been widely used to acquire images of lithium dendrites with high resolution and high quality. Although electron microscopy has the potential to provide insight into dendrite formation, its sample preparation requirements are very demanding. Therefore, it is very challenging for in situ observa...

AI Technical Summary

Problems solved by technology

[0004] i), unable to realize three-dimensional imaging; ii), low spatial resolution, not reaching the micron level; iii), unable to observe the dendrite growth in the diaphragm; iv), unable to observe the microstructure of "bulk lithium dendrite"; v), Very demanding sample preparation requirements, making it unsuitable for in situ observation; vi), slow imaging speed and low temporal resolution

Specifically: a), the disadvantages of the electron microscope are iv and v; b), the disadvantages of the X-ray tomography scanner are iv and vi; c), the disadvantages of the magnetic resonance imaging are ii; d), the disadvantages of the optical microscope are i

Furthermore, all these 4 techniques have disadvantages iii

Images