Transmission electron microscope in-situ imaging method with large field of view and high temporal-spatial resolution for microscopic electrochemical process

Abstract

The invention discloses a large-view-field and high-temporal-spatial-resolution transmission electron microscope in-situ imaging method for a microcosmic electrochemical process, which comprises the following steps: step 1, loading an electrode material particle sample to be detected on a carrying table, inserting the sample into a transmission electron microscope vacuum lens cone along with a sample rod, identifying a target sample under low magnification, and carrying out basic adjustment on an electron microscope; 2, adjusting magnification times to ensure that an observation area is completely incorporated into an imaging view field, selecting an imaging mode, eliminating astigmatism, and adjusting the focal length of an objective lens until a sample particle image interface is clear; and step 3, selecting a CCD camera, setting an acquisition frame rate, and performing ultrafast acquisition of images or videos. The transmission electron microscope in-situ imaging technology giving consideration to both the large view field and the high space-time resolution has practical application value in research of the electrochemical reaction kinetics process of the granular material.

Description

Technical Field

[0001] This invention relates to a transmission electron microscopy in-situ imaging method with a large field of view and high spatiotemporal resolution for microscopic electrochemical processes. This imaging method can take into account a large field of view at the micrometer level, a spatial resolution at the nanometer level, and a temporal resolution at the millisecond level. It can realize real-time tracking of electrochemical reaction processes between multiple particles and belongs to the field of energy storage material dynamics research and in-situ imaging technology. Background Technology

[0002] For a long time, transmission electron microscopy (TEM) has faced three major technical challenges in practical applications, severely limiting its effectiveness in studying dynamic, multi-particle systems. These challenges include: small imaging field of view, insufficient temporal resolution, and decreased spatial resolution under large fields of view. The imaging field of TEM is typically limited to the micrometer scale, making it difficult to simultaneously capture the behavior of multiple nanoparticles in electrochemical reactions. Electrochemical reactions often involve synergistic effects, aggregation, or competitive reactions between particles; observing only a single or a few particles may miss crucial overall dynamic information. For example, in studying the sulfur reduction reaction in lithium-sulfur batteries, the shuttle effect of polysulfides between multiple particles requires observation under a large field of view for a comprehensive understanding. To expand the field of view, scanning transmission electron microscopy (STEM) mode or combined with low-magnification imaging techniques have been attempted, but this often comes at the cost of resolution. Furthermore, the temporal resolution of TEM is limited by the acquisition speed of the electron detector, the electron beam dose, and the signal-to-noise ratio; imaging requires acquiring a single image every few seconds to minutes, making it difficult to capture rapid dynamic processes in electrochemical reactions, such as ion diffusion, phase transitions, or interfacial reactions during battery charging and discharging. Millisecond-level imaging is crucial for observing these transient processes, but achieving it faces multiple obstacles, such as rapid acquisition reducing image contrast. In recent years, the development of direct electron detectors (such as CMOS cameras) has improved temporal resolution to the millisecond level, but data transmission and processing speeds remain a limitation in continuous multi-image imaging. Furthermore, when expanding the field of view to observe multiple particles, the spatial resolution of transmission electron microscopy often decreases significantly. This stems from the cumulative effect of aberrations (such as spherical aberration and chromatic aberration), as well as image distortion caused by sample tilt or uneven thickness. In electrochemical research, the interface structure, lattice changes, or defect evolution of nanoparticles often require sub-nanometer resolution, but large field-of-view imaging can blur these details. Current technologies struggle to balance large field of view with high spatiotemporal resolution.

[0003] To overcome these limitations, improvement solutions are being explored from multiple angles. Regarding expanding the field of view, computational imaging techniques (such as stacked imaging) reconstruct large field-of-view images through algorithms, achieving nanometer resolution within a micrometer-scale field of view. In terms of temporal resolution, ultrafast TEM and pump-probe techniques can shorten imaging time to the picosecond level, but these methods involve high equipment complexity. Recently, machine learning-assisted image analysis has been able to extract dynamic information from unoptimized data, reducing reliance on hardware limitations. Regarding spatial resolution, continuous optimization of aberration correctors and the development of electronic holography promise to improve the quality of large field-of-view imaging. However, to date, no practical in-situ imaging technique has been achieved in transmission electron microscopy that simultaneously achieves a micrometer-scale large field of view, nanometer-scale spatial resolution, and millisecond-level temporal resolution. Summary of the Invention

[0004] Technical bottlenecks in transmission electron microscopy (TEM) imaging of electrochemical reactions still require interdisciplinary collaboration to overcome. While the combination of hardware innovation and artificial intelligence analysis promises to enable dynamic observations with large fields of view and high spatiotemporal resolution in the future, driving the development of energy materials and catalysis science, there is still an urgent need to develop a practical in-situ TEM imaging technique to address the needs of studying the structure-activity mechanism of high-performance batteries—the cornerstone of new energy strategies. Therefore, the purpose of this invention is to provide a large field of view and high spatiotemporal resolution TEM in-situ imaging method for microscopic electrochemical processes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A large field-of-view and high spatiotemporal resolution in-situ transmission electron microscopy imaging method for microscopic electrochemical processes includes the following steps:

[0007] Step 1: Load the electrode material particle sample to be tested onto the stage, insert it into the vacuum tube of the transmission electron microscope along with the sample rod, identify the target sample under low magnification, and make basic adjustments to the electron microscope;

[0008] Step 2: Adjust the magnification to ensure that the observation area is completely included in the imaging field of view, select the imaging mode, and eliminate astigmatism and adjust the objective lens focal length until the sample particle image interface is clear.

[0009] Step 3: Select the CCD camera and set the acquisition frame rate for ultra-fast image or video acquisition.

[0010] Furthermore, in step one, the basic adjustments include electron gun alignment, condenser lens alignment, and objective lens aperture alignment.

[0011] Furthermore, in step one, the stage used for loading the sample is a metal wire or a TEM carbon film copper mesh; the sample rod used is a single-tilt or double-tilt electrical testing system TEM sample rod.

[0012] Furthermore, in step two, the diagonal length of the imaging field of view is not less than 5 micrometers, and the spatial resolution of the sample particles is less than 100 nanometers.

[0013] Furthermore, in step two, the imaging mode is a bright-field image, a dark-field image, or a filtered image.

[0014] Furthermore, in step three, the set acquisition frame rate satisfies that the temporal resolution of image and video acquisition is better than 10 milliseconds.

[0015] Furthermore, in step three, the CCD camera is a K3 camera or a DECTRIS camera, with a frame rate range of 100~1000 fps.

[0016] Furthermore, in step three, the ultrafast acquisition of the image or video is used to track the dynamic process of the microscopic electrochemical reaction.

[0017] Furthermore, the method simultaneously achieves an imaging field of view with a diagonal length of not less than 5 micrometers, a sample particle spatial resolution of less than 100 nanometers, and a temporal resolution better than 10 milliseconds.

[0018] Beneficial effects: (1) The present invention provides a large field of view and high spatiotemporal resolution transmission electron microscopy in-situ imaging technique for microscopic electrochemical processes, which helps to solve the technical challenges faced by transmission electron microscopy in practical applications, such as small imaging field of view, insufficient temporal resolution, and decreased spatial resolution under large field of view. It can realize the simultaneous capture of the electrochemical reaction behavior of multiple nanoparticles at the micrometer scale. (2) At present, no literature or patent has reported the index requirements for large field of view and high spatiotemporal resolution imaging achieved by the technology of the present invention. Therefore, the in-situ imaging technique of the present invention fills this gap and can be extended to the study of electrochemical microscopic processes in fields such as catalysis and hydrolysis. Attached Figure Description

[0019] Figure 1 This is a transmission electron microscope image of a micrometer-scale large field of view achieved by the technology of this invention, wherein the diagonal length of the image is 10 micrometers.

[0020] Figure 2 These are transmission electron microscope (TEM) images with a micrometer-scale large field of view, nanometer-scale spatial resolution, and millisecond-scale temporal resolution achieved by the technology of this invention. The diagonal length of the images is 15 micrometers, the spatial resolution of a single nanoparticle is 30 nanometers, and the acquisition frame rate is 1000 fps. Detailed Implementation

[0021] To better understand the invention, the invention will be further described below with reference to examples and accompanying drawings.

[0022] Example 1

[0023] (1) Load the electrode material particle sample to be tested onto a special stage and insert it into the vacuum tube of the transmission electron microscope along with the sample rod. Then, identify the target sample under low magnification and perform a series of adjustments such as electron gun alignment, condenser lens alignment, and objective lens aperture alignment. The stage used for sample loading is a metal wire or TEM carbon film copper mesh, and the sample rod used for the sample stage is a single-tilt electrical testing system TEM sample rod.

[0024] (2) Adjust the magnification to ensure that the observation area is fully included in the imaging field of view. Select the dark field imaging mode as needed, and eliminate astigmatism and adjust the objective lens focal length until the sample particle image interface is clear. The diagonal length of the imaging field of view is 5 micrometers, and the spatial resolution of the sample particles is 100 nanometers.

[0025] (3) By selecting a DECTRIS CCD camera and setting the acquisition frame rate to 100 fps, ultra-fast acquisition of images or videos can be achieved. The time resolution of image and video acquisition is 10 milliseconds.

[0026] Example 2

[0027] (1) Load the electrode material particle sample to be tested onto a special stage and insert it into the vacuum tube of the transmission electron microscope along with the sample rod. Then, identify the target sample under low magnification and perform a series of adjustments such as electron gun alignment, condenser lens alignment, and objective lens aperture alignment. The stage used for sample loading is a metal wire or TEM carbon film copper mesh, and the sample rod used for the sample stage is a TEM sample rod of the double tilt electrical testing system.

[0028] (2) Adjust the magnification to ensure that the observation area is fully included in the imaging field of view. Select the bright field imaging mode as needed, and eliminate astigmatism and adjust the objective lens focal length until the sample particle image interface is clear. The diagonal length of the imaging field of view is 10 micrometers, and the spatial resolution of the sample particles is 50 nanometers.

[0029] (3) By selecting a K3 CCD camera and setting the acquisition frame rate to 200 fps, ultra-fast acquisition of images or videos can be achieved. The time resolution of image and video acquisition is 5 milliseconds.

[0030] Figure 1 This is a video image of in-situ transmission electron microscopy imaging with a large field of view at the micrometer level, as achieved in this embodiment. The diagonal length of the image is 10 micrometers.

[0031] Example 3

[0032] (1) Load the electrode material particle sample to be tested onto a special stage and insert it into the vacuum tube of the transmission electron microscope along with the sample rod. Then, identify the target sample under low magnification and perform a series of adjustments such as electron gun alignment, condenser lens alignment, and objective lens aperture alignment. The stage used for sample loading is a metal wire or TEM carbon film copper mesh, and the sample rod used for the sample stage is a TEM sample rod of the double tilt electrical testing system.

[0033] (2) Adjust the magnification to ensure that the observation area is fully included in the imaging field of view. Select the bright field imaging mode as needed, and eliminate astigmatism and adjust the objective lens focal length until the sample particle image interface is clear. The diagonal length of the imaging field of view is 15 micrometers, and the spatial resolution of the sample particles is 30 nanometers.

[0034] (3) By selecting a K3 type CCD camera and setting the acquisition frame rate to 1000 fps, ultra-fast acquisition of images or videos can be achieved. The time resolution of image and video acquisition is 1 millisecond.

[0035] Figure 2 This embodiment presents in-situ transmission electron microscopy (TEM) imaging video images with a micrometer-scale large field of view, nanometer-scale spatial resolution, and millisecond-scale temporal resolution. The diagonal length of the images is 15 micrometers, the spatial resolution of a single nanoparticle is 30 nanometers, the video image acquisition frame rate is 1000 fps, and the temporal resolution is 1 millisecond.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A large field-of-view and high spatiotemporal resolution in-situ transmission electron microscopy imaging method for microscopic electrochemical processes, characterized in that: Includes the following steps: Step 1: Load the electrode material particle sample to be tested onto the stage, insert it into the vacuum tube of the transmission electron microscope along with the sample rod, identify the target sample under low magnification, and make basic adjustments to the electron microscope; Step 2: Adjust the magnification to ensure that the observation area is completely included in the imaging field of view, select the imaging mode, and eliminate astigmatism and adjust the objective lens focal length until the sample particle image interface is clear. Step 3: Select the CCD camera and set the acquisition frame rate for ultra-fast image or video acquisition.

2. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: In step one, the basic adjustments include electron gun alignment, condenser lens alignment, and objective lens aperture alignment.

3. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: In step one, the stage used for loading the sample is a metal wire or a TEM carbon film copper mesh; the sample rod used is a single-tilt or double-tilt electrical testing system TEM sample rod.

4. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: In step two, the diagonal length of the imaging field of view is not less than 5 micrometers, and the spatial resolution of the sample particles is less than 100 nanometers.

5. The in-situ imaging method for transmission electron microscopy according to claim 1 or 4, characterized in that: In step two, the imaging mode is bright field image, dark field image, or filtered image.

6. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: In step three, the set frame rate satisfies that the temporal resolution of image and video acquisition is better than 10 milliseconds.

7. The in-situ imaging method for transmission electron microscopy according to claim 1 or 6, characterized in that: In step three, the CCD camera is a K3 camera or a DECTRIS camera, and the frame rate range is 100~1000 fps.

8. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: In step three, the ultrafast acquisition of images or videos is used to track the dynamic process of microscopic electrochemical reactions.

9. The in-situ imaging method for transmission electron microscopy according to claim 1, characterized in that: The method simultaneously achieves an imaging field of view with a diagonal length of not less than 5 micrometers, a sample particle spatial resolution of less than 100 nanometers, and a temporal resolution better than 10 milliseconds.

Images