Single two-dimensional material nanosheet electrode in-situ optical observation device and observation method
By designing an in-situ optical observation device for two-dimensional material nanosheet electrodes, the problem of difficult to observe the real-time structural changes of the electrodes during charging and discharging in the prior art is solved, and high efficiency is achieved in real electrochemical environment Observation provides accurate data guidance for modification covering.
Patent Information
- Application Number
- CN202411514516.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-02-14
AI Technical Summary
It is difficult to accurately observe the real-time structure and morphological evolution of two-dimensional material nanosheet electrodes during charging and discharging, and the non-in-situ characterization methods have problems such as sample contamination and mechanical degradation.
Design a single two-dimensional material nanosheet electrode in situ optical observation device, including a chassis and transparent observation cover, the nanosheet electrode and electrolyte are observed in a real liquid electrolyte environment, and the shape and structure of the nanosheet are directly observed through an optical microscope. Evolution.
Real-time observation of the electrodes of two-dimensional material nanosheets in a real electrochemical environment is achieved, instantaneous changes in the charging and discharging process are captured, more accurate and reliable data are provided, and the modification and coating of two-dimensional materials is guided.
Smart Images
Figure CN119438080A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrochemical cells, and in particular to an in-situ optical observation device and method for a single two-dimensional material nanosheet electrode. Background Art
[0002] Two-dimensional materials stacked by van der Waals forces have attracted considerable attention, including transition metal chalcogenides, transition metal carbides, transition metal nitrides, etc. Two-dimensional materials exhibit ultra-thin atomic / molecular layered structures, exist in sheet form, have infinite plane length and more exposed internal atoms, can store guest ions such as lithium, sodium, potassium between layers, and can undergo conversion reactions under deep discharge, providing excellent theoretical capacity. In addition, they can also exhibit tunable chemical and electrical properties by controlling defects. Therefore, they are widely developed for energy storage systems.
[0003] Although the above two-dimensional materials have some extraordinary advantages, they must overcome serious obstacles before they can be used for electrochemical energy storage: they suffer considerable volume changes during the charge and discharge process, causing structural damage, and in severe cases, mechanical failure of the electrode. Therefore, effective modification methods are needed to protect the two-dimensional material electrodes, enhance their mechanical properties, inhibit the structural damage of the sheet materials, and stabilize the electrochemical performance of the battery. This requires efficient, intuitive, and reliable characterization methods to study the structural and morphological evolution of two-dimensional material nanosheets during the charge and discharge process, thereby guiding the modification of two-dimensional materials.
[0004] Although the non-in-situ characterization technology in current research can provide information on the structural morphology changes of two-dimensional nanosheet electrode materials, its test results may not be completely accurate for three reasons:
[0005] (1) During the charge and discharge cycle, the transient and non-equilibrium processes of the reaction, that is, the intermediate processes, are difficult to observe.
[0006] (2) Ex situ characterization requires disassembling the battery to remove the electrode sheet, which must be clamped with tools such as tweezers, and repeatedly cleaned, dried, and transferred. This may cause sample contamination and other irreversible effects, thereby misleading the understanding of processes such as mechanical degradation and reaction mechanisms.
[0007] (3) In ex situ characterization, it is technically extremely difficult to track the same 2D material nanosheet through multiple repeated charge and discharge cycles.
[0008] Although the in-situ characterization of a single two-dimensional material nanosheet can solve the above problems, such as (in-situ scanning electron microscope imaging, in-situ transmission electron microscope imaging), the micro-device required for the in-situ electron microscope characterization is complex in structure and very expensive, and the electron beam will cause significant radiation damage to the thin layer material. In addition, the electrochemical environment of the nanosheet electrode is not a real electrochemical environment, because liquid electrolytes cannot be used in current in-situ electron microscope characterization instruments. Therefore, it is urgent to design an in-situ optical observation device for two-dimensional material nanosheets with low cost, simple structure, cheap operation, and real test environment. Summary of the invention
[0009] One of the purposes of the present invention is to provide an in-situ optical observation device for a single two-dimensional material nanosheet electrode, which has low cost, simple structure, and cheap operation. The morphology and structural evolution of a single two-dimensional material nanosheet during the charge and discharge process can be directly observed in situ by an optical microscope in a real liquid electrolyte environment, thereby effectively guiding the modification and coating work of the two-dimensional material nanosheet electrode.
[0010] The second purpose of the present invention is to provide an in-situ optical observation method for a single two-dimensional material nanosheet electrode. The method is simple and can directly observe the morphology and structural evolution of a single two-dimensional material nanosheet during the charge and discharge process through an optical microscope in a real liquid electrolyte environment.
[0011] The solution adopted by the present invention to achieve one of the purposes is: an in-situ optical observation device for a single two-dimensional material nanosheet electrode, comprising a chassis and a transparent observation cover, wherein a nanosheet electrode, a counter / reference electrode and an electrolyte are sandwiched between the chassis and the transparent observation cover, wherein the nanosheet electrode and the counter / reference electrode are at least partially immersed in the electrolyte, the counter / reference electrode and the nanoelectrode are externally connected to electrode leads, and the nanosheet electrode is composed of a substrate, a single two-dimensional material nanosheet arranged on the surface of the substrate, and a conductive metal film covering the surface of the substrate and in contact with the single two-dimensional material nanosheet.
[0012] The observation cover is made of a transparent material, which may be optical glass or quartz.
[0013] The two-dimensional material nanosheet is a transition metal chalcogenide, a transition metal carbide / nitride, etc. Preferably, the transition metal chalcogenide nanosheet is any one of vanadium diselenide, vanadium disulfide, molybdenum diselenide, molybdenum disulfide, tungsten diselenide, tungsten disulfide, etc.
[0014] Preferably, a cavity is provided between the bottom plate and the transparent observation cover, and one end of the nanosheet electrode, one end of the counter / reference electrode and the electrolyte are placed in the cavity.
[0015] Preferably, the observation cover is provided with an electrolyte injection port.
[0016] Preferably, the counter / reference electrode is any one of lithium, sodium, potassium, calcium, magnesium, zinc, and aluminum metal sheets; the thickness of the counter / reference electrode is 0.2-0.5 mm.
[0017] Preferably, the lateral size of the single two-dimensional material nanosheet electrode is -10-30 microns.
[0018] Preferably, the substrate is a stainless steel substrate or a Si / SiO2 substrate with a thickness of 0.2-0.5 mm cm, and the thickness of the SiO2 layer is 200-300 nm nm.
[0019] Preferably, the single two-dimensional material nanosheet may be prepared by any one of chemical vapor deposition and chemical vapor transport.
[0020] Preferably, the conductive metal film may be any one of a copper film, a gold film and a platinum film, and may be realized by any one of evaporation and photolithography techniques.
[0021] Preferably, the electrode lead is at least one of copper wire, gold wire, silver wire, platinum wire and stainless steel wire, and the electrode lead is connected to the nanosheet electrode and the counter / reference electrode through conductive silver paste or soldering and fixed through polyethylene epoxy resin.
[0022] The solution adopted by the present invention to achieve the second purpose is: an in-situ optical observation method of a single two-dimensional material nanosheet electrode, using the device for observation, the specific steps are: connecting the two electrode leads of the device to the battery testing system respectively, and placing the device under an optical microscope, adjusting the focal length, and then applying current to perform constant current charge and discharge testing.
[0023] The present invention has the following advantages and beneficial effects:
[0024] By using the device of the present invention, the real-time evolution of the structure morphology of a single two-dimensional material nanosheet electrode during the charging and discharging process can be directly observed through an optical microscope, which is conducive to capturing instantaneous changes.
[0025] The electrolyte of the in-situ device provided by the present invention is in liquid state, which restores the real battery environment and avoids the error in the results caused by the use of the oxidized metal layer as the electrolyte in the in-situ electron microscopy characterization, which is conducive to providing more accurate and reliable guidance for strategies such as modification and coating of two-dimensional material nanosheets.
[0026] In addition, the preparation cost of the present invention is lower and the operation is simpler. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a schematic diagram of the structure of the in-situ optical observation device for a single two-dimensional material nanosheet electrode of the present invention;
[0028] Figure 2 It is a schematic structural diagram of the in-situ optical observation device for a single two-dimensional material nanosheet electrode of the present invention after the transparent observation cover is cut open;
[0029] Figure 3 It is a schematic diagram of the structure of the nanosheet electrode of the present invention;
[0030] Figure 4 An optical microscope image of a two-dimensional material (vanadium diselenide) nanosheet grown by chemical vapor deposition;
[0031] Figure 5 Optical microscopy image of vanadium diselenide nanosheets covered with a patterned conductive metal film;
[0032] Figure 6 Optical images of the structural morphology evolution of a single two-dimensional material (vanadium diselenide) nanosheet in the in-situ optical observation device under different charge and discharge states in Example 2;
[0033] Figure 7 An optical image of the structural morphology evolution of a single two-dimensional material (vanadium diselenide) nanosheet coated with a tough polymer coating in the in-situ optical observation device under different charge and discharge states in Example 3;
[0034] Among them, 1. chassis; 2. transparent observation cover; 201. electrolyte injection port; 3. nanosheet electrode; 301. Si / SiO2 substrate; 302. single two-dimensional material nanosheet; 303. metal film; 4. electrolyte; 5. counter / reference electrode; 6. electrode lead; 7. conductive silver paste; 8. optical microscope lens. DETAILED DESCRIPTION
[0035] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.
[0036] Example 1
[0037] like Figure 1-3 As shown, a single two-dimensional material nanosheet electrode in-situ optical observation device comprises: a chassis 1 and a transparent observation cover 2; a nanosheet electrode 3, an electrolyte 4, and a counter / reference electrode 5 are sandwiched between the chassis 1 and the transparent observation cover 2. A cavity is formed between the chassis 1 and the transparent observation cover 2, and a portion of the nanosheet electrode 3 and the counter / reference electrode 5 and the electrolyte 4 are accommodated in the cavity, and one end of the nanosheet electrode 3 and the counter / reference electrode 5 is immersed in the electrolyte 4.
[0038] In this embodiment, the nanosheet electrode is composed of a Si / SiO2 substrate 301, a single two-dimensional material nanosheet 302 and a conductive metal film 303 patterned on the nanosheet, and the nanosheet electrode 3 and the counter / reference electrode 5 are respectively connected to electrode leads 6. In other embodiments, the substrate may also be a stainless steel substrate.
[0039] In this embodiment, the radius of the bottom plate 1 is greater than the radius of the transparent observation cover 2 , and the transparent observation cover 2 is provided with an electrolyte injection port 201 .
[0040] In this embodiment, the observation cover is made of a transparent material, which may be optical glass or quartz.
[0041] The counter / reference electrode 5 can be a metal sheet such as lithium, sodium, potassium, calcium, magnesium, zinc, aluminum, etc.; the thickness of the counter electrode is preferably 0.2-0.5 mm.
[0042] The lateral size of the single two-dimensional material nanosheet is preferably -10-30 microns.
[0043] The thickness of the Si / SiO2 substrate is preferably 0.2-0.5 cm. In this embodiment, the thickness of the SiO2 layer is preferably 200-300 nanometers.
[0044] The single two-dimensional material nanosheet 302 may be prepared by chemical vapor deposition or chemical vapor transport.
[0045] The patterned conductive metal film 303 may be any one of a copper film, a gold film, and a platinum film, and may be realized by any one of evaporation and photolithography techniques.
[0046] Preferably, the electrode lead 6 can be made of copper wire, gold wire, silver wire, platinum wire, or stainless steel wire. In this embodiment, copper wire is preferred. The electrode lead 6 is connected to the electrode through a conductive silver paste 7 and fixed through polyethylene epoxy resin.
[0047] Example 2
[0048] A method for in-situ optical observation of a single two-dimensional material nanosheet electrode comprises the following steps:
[0049] First, prepare an in-situ optical observation device for a single two-dimensional material nanosheet electrode, and then perform in-situ observation:
[0050] S1: Preparation of two-dimensional material nanosheets: Select a 1*2 cm Si / SiO2 substrate and ultrasonicate it in acetone, anhydrous ethanol, and deionized water for 5 minutes each to fully clean the Si / SiO2 substrate, and then blow it dry with a nitrogen gun. Then grow vanadium diselenide nanosheets by atmospheric pressure chemical vapor deposition: Use a two-zone tubular furnace with separate temperature control to place 0.1g of vanadium trichloride powder, 0.6g of selenium powder, and a cleaned Si / SiO2 substrate on a quartz boat. Selenium powder and vanadium trichloride powder are placed in the middle of the upstream temperature zone and the partition between the two temperature zones, respectively, and the Si / SiO2 substrate is placed about 5 cm downstream of the vanadium trichloride powder. Then use a 95% nitrogen + 5% hydrogen mixture to purge with a flow rate of 200sccm. At the same time, the chamber double temperature zone is raised from room temperature to 120°C within 10 minutes, and maintained for 10 minutes to exhaust oxygen and moisture in the chamber. Next, the mixed gas flow rate was reduced to 50 sccm. At the same time, the upstream and downstream temperature zones were raised to 370°C and 600°C within 30 minutes, respectively. After 10 minutes, the furnace was allowed to enter a natural cooling process. The samples were taken out for later use. The optical image of the vanadium diselenide nanosheets on the Si / SiO2 substrate is shown in Figure 2. Figure 4 shown.
[0051] S2: Nanosheet electrode fabrication: The overall structure of the nanosheet electrode is as follows: Figure 2 As shown in the figure, a vanadium diselenide nanosheet with a flat surface that is easy to observe is selected, and then the gold electrode is patterned on the vanadium diselenide nanosheet by electron beam lithography, electron beam deposition and standard lift-off process. The pattern of the gold electrode is a rectangle with a size of 500*800 microns. The short edge of the rectangular gold pattern covers no more than 1 / 2 of the vanadium diselenide nanosheet. The final optical image of the nanosheet electrode is as follows Figure 5 shown.
[0052] S3: Assembly of in-situ optical observation device: Select two transparent quartz plates. The radius of the transparent quartz plate used as the chassis is twice the radius of the observation cover, and then a small hole is punched near the outer edge of the observation cover as the electrolyte injection port; the nanosheet electrode obtained in step S2 is transferred to a glove box with an argon atmosphere, and then a polished magnesium strip (0.2 cm thick) is used as the negative electrode and the nanosheet electrode is used as the positive electrode. The two are fixed on both sides of the chassis by polyethylene epoxy resin, and the end of the nanosheet on the positive electrode side is close to the center of the chassis, and the front end of the Si / SiO2 substrate is about 0.2 cm away from the front end of the negative electrode; the observation cover is placed on the two electrodes and aligned with the central axis of the chassis, and then the edge gap is sealed by polyethylene epoxy resin; the prepared copper wire is fixed to the two ends of the magnesium negative electrode and the nanosheet electrode respectively by conductive silver paste; a tetrahydrofuran solution of 0.4M APC+1M LiCl is used as a magnesium-lithium dual salt electrolyte to fill the in-situ optical observation device through the electrolyte injection port, and finally the electrolyte injection port is sealed by polyethylene epoxy resin.
[0053] S4: In situ optical characterization of a single nanosheet electrode: Connect the two electrode leads of the in situ optical observation device to the LAND battery test system, place the nanosheet under the optical microscope, adjust the focus, and then apply 10 mA cm -2 A constant current charge and discharge test was carried out at a current density of 1000 nm to observe the changes in the nanosheets.
[0054] Figure 6 The structural morphology changes of vanadium diselenide nanosheets in the initial state, fully discharged state, and fully charged state are shown. It can be clearly seen that in the initial state, vanadium diselenide presents a uniform translucent appearance under an optical microscope. After the discharge of VSe2, a significant color change was observed in the bare vanadium diselenide flakes under an optical microscope. The edges of the initially uniform and translucent vanadium diselenide nanosheets darkened significantly at the end of the discharge, and the intensity of the darkening decreased from the edge to the center. Obviously, this is due to the lithiation and magnesium of the vanadium diselenide nanosheets. When guest ions are inserted into vanadium diselenide, unbalanced stress is generated at the interface, causing stress concentration and leading to local structural deformation. This phenomenon recovered slightly after the end of charging, but still left a black mark, which means that irreversible structural damage has been left.
[0055] Example 3
[0056] A method for in-situ optical observation of a single two-dimensional material nanosheet electrode comprises the following steps:
[0057] First, prepare an in-situ optical observation device for a single two-dimensional material nanosheet electrode, and then perform in-situ observation:
[0058] S1: Preparation of two-dimensional material nanosheets: Select a 1*2 cm Si / SiO2 substrate and ultrasonicate it in acetone, anhydrous ethanol, and deionized water for 5 minutes each to fully clean the Si / SiO2 substrate, and then blow it dry with a nitrogen gun. Then grow vanadium diselenide nanosheets by atmospheric pressure chemical vapor deposition: Use a two-zone tubular furnace with separate temperature control to place 0.1g of vanadium trichloride powder, 0.6g of selenium powder, and a cleaned Si / SiO2 substrate on a quartz boat. Selenium powder and vanadium trichloride powder are placed in the middle of the upstream temperature zone and the partition between the two temperature zones, respectively, and the Si / SiO2 substrate is placed about 5 cm downstream of the vanadium trichloride powder. Then use a 95% nitrogen + 5% hydrogen mixture to purge with a flow rate of 200sccm. At the same time, the chamber double temperature zone is raised from room temperature to 120°C within 10 minutes, and maintained for 10 minutes to exhaust oxygen and moisture in the chamber. Next, the mixed gas flow rate was reduced to 50 sccm, and at the same time, the upstream and downstream temperature zones were raised to 370°C and 600°C within 30 minutes, respectively. After 10 minutes, the furnace was allowed to enter a natural cooling process, and the sample was taken out for use. Subsequently, the vanadium diselenide nanosheets were coated with a poly(3,4-ethylenedioxythiophene) (PEDOT) protective layer by a molecular layer deposition process. MoCl5 was used as an oxidant, EDOT as a reaction monomer, and 150 sccm of nitrogen as a carrier gas. Deposition was performed at 150°C. The cycle process included -1s EDOT pulse + -100s nitrogen pulse + -5s MoCl5 pulse + -100s nitrogen pulse, and 10 cycles of deposition were performed to obtain vanadium diselenide@PEDOT nanosheets.
[0059] S2: Nanosheet electrode preparation: A vanadium diselenide@PEDOT nanosheet with a flat surface that is easy to observe is selected, and then a gold electrode is patterned on the vanadium diselenide@PEDOT nanosheet by electron beam lithography, electron beam deposition and standard lift-off process respectively. The pattern of the gold electrode is a rectangle with a size of 500*800 microns, and the short edge of the rectangular gold film covers no more than 1 / 2 of the vanadium diselenide nanosheet.
[0060] S3: Assembly of in-situ optical observation device: Select two transparent quartz plates. The radius of the transparent quartz plate used as the chassis is twice the radius of the observation cover, and then a small hole is punched near the outer edge of the observation cover as an electrolyte injection port; the nanosheet electrode obtained in step S2 is transferred to a glove box with an argon atmosphere, and then a polished magnesium strip (0.2 cm thick) is used as the negative electrode and the nanosheet electrode is used as the positive electrode. The two are fixed on both sides of the chassis by polyethylene epoxy resin, and the end of the nanosheet on the positive electrode side is close to the center of the chassis, and the front end of the Si / SiO2 substrate is about 0.2 cm away from the front section of the negative electrode; the observation cover is placed on the two electrodes and aligned with the central axis of the chassis, and then the edge gap is sealed by polyethylene epoxy resin; the prepared copper wire is fixed to the two ends of the magnesium negative electrode and the nanosheet electrode respectively by conductive silver paste; a tetrahydrofuran solution of 0.4M APC+1M LiCl is used as a magnesium-lithium dual salt electrolyte to fill the in-situ optical observation device through the electrolyte injection port, and finally the electrolyte injection port is sealed by polyethylene epoxy resin.
[0061] S4: In situ optical characterization of a single nanosheet electrode: Connect the two electrode leads of the in situ optical observation device to the LAND battery test system, place the nanosheet under the optical microscope, adjust the focus, and then apply 10 mA cm -2 A constant current charge and discharge test was carried out at a current density of 1000 nm to observe the changes in the nanosheets.
[0062] Figure 7 The structural morphology changes of vanadium diselenide @PEDOT nanosheets in the initial state, fully discharged state, and fully charged state are shown. It can be clearly seen that in the initial state, vanadium diselenide @PEDOT presents a uniform translucent appearance under an optical microscope. After the discharge of vanadium diselenide, the color change of the nanosheets observed under an optical microscope is not obvious, and the translucent appearance is maintained. There is also little change after charging. This is in sharp contrast to the sample in Example 1, which means that the tough PEDOT coating layer plays an excellent protective role, which further reflects the guiding significance of the present invention for the modification and coating of two-dimensional material nanosheet electrode materials.
[0063] Example 4
[0064] A method for in-situ optical observation of a single two-dimensional material nanosheet electrode comprises the following steps:
[0065] First, prepare an in-situ optical observation device for a single two-dimensional material nanosheet electrode, and then perform in-situ observation:
[0066] S1: Preparation of two-dimensional material nanosheets: Select a 1*2 cm Si / SiO2 substrate and ultrasonicate it in acetone, anhydrous ethanol, and deionized water for 5 minutes each to fully clean the Si / SiO2 substrate, and then blow it dry with a nitrogen gun. Then grow molybdenum disulfide nanosheets by atmospheric pressure chemical vapor deposition: Use a two-zone tubular furnace with separate temperature control to place 0.1g of molybdenum trioxide powder, 0.6g of sulfur powder, and a cleaned Si / SiO2 substrate on a quartz boat. Place the sulfur powder and molybdenum trioxide powder in the middle of the upstream temperature zone and the partition between the two temperature zones, respectively, and place the Si / SiO2 substrate about 5 cm downstream of the molybdenum trioxide powder. Then use a 95% nitrogen + 5% hydrogen mixture to purge with a flow rate of 200sccm. At the same time, the chamber double temperature zone rises from room temperature to 120°C within 10 minutes, and is maintained for 10 minutes to exhaust oxygen and moisture in the chamber. Next, the mixed gas flow rate was reduced to 70 sccm, and at the same time, the upstream and downstream temperature zones were raised to 200°C and 900°C within 30 minutes, respectively. After 10 minutes, the furnace was allowed to enter a natural cooling process, and the samples were taken out for later use.
[0067] S2: Preparation of nanosheet electrodes: Select a 500*800 micron rectangular mask, transfer the Si / SiO2 substrate with MoS2 nanosheets grown on it to a vacuum evaporator, and evaporate by heating the copper source, so as to pattern the copper electrode on the MoS2 nanosheet with the help of the mask. The short edge of the rectangular copper film covers no more than 1 / 2 of the MoS2 nanosheet.
[0068] S3: Assembly of the in-situ optical observation device: Select two transparent quartz plates. The radius of the transparent quartz plate as the chassis is twice the radius of the observation cover. Then, a small hole is punched near the outer edge of the observation cover as the electrolyte injection port; the nanosheet electrode obtained in step S2 is transferred to a glove box with an argon atmosphere, and then the lithium sheet (10 mm in diameter, 0.2 cm thick) pressed on one end of a rectangular stainless steel mesh (1*2 cm) is used as the negative electrode, and the nanosheet electrode is used as the positive electrode. The two are fixed to both sides of the chassis by polyethylene epoxy resin, and the end of the nanosheet on the positive electrode side is close to the center of the chassis, and the front end of the Si / SiO2 substrate is It is about 0.2cm away from the front section of the negative electrode; put the observation cover on the two electrodes and align it with the central axis of the chassis, taking care to completely cover the lithium sheet, and then seal the edge gap with polyethylene epoxy resin; fix the prepared copper wire to the exposed stainless steel mesh and one end of the nanosheet electrode respectively with conductive silver paste; the electrolyte is 1M LiTFSI dissolved in dimethoxyethane and 1,3-dioxolane in a volume ratio of 1:1, fill the in-situ optical observation device through the electrolyte injection port, and finally seal the electrolyte injection port with polyethylene epoxy resin.
[0069] S4: In situ optical characterization of a single nanosheet electrode: Connect the two electrode leads of the in situ optical observation device to the LAND battery test system, place the nanosheet under the optical microscope, adjust the focus, and then apply 10 mA cm -2 The constant current charge and discharge test was carried out with a current density of 1.
[0070] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.
Claims
1. An in-situ optical observation device for a single two-dimensional material nanosheet electrode, characterized in that: It includes a chassis and a transparent observation cover, wherein a nanosheet electrode, a counter / reference electrode and an electrolyte are sandwiched between the chassis and the transparent observation cover, wherein the nanosheet electrode and the counter / reference electrode are at least partially immersed in the electrolyte, and the counter / reference electrode and the nanoelectrode are externally connected to electrode leads, and the nanosheet electrode is composed of a substrate, a single two-dimensional material nanosheet arranged on the surface of the substrate, and a conductive metal film covering the surface of the substrate and in contact with the single two-dimensional material nanosheet, wherein the two-dimensional material nanosheet is at least one of a transition metal sulfide, a transition metal carbide, and a transition metal nitride.
2. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: A cavity is arranged between the bottom plate and the transparent observation cover, and one end of the nanosheet electrode, one end of the counter / reference electrode and the electrolyte are placed in the cavity.
3. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The observation cover is provided with an electrolyte injection port.
4. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The counter / reference electrode is any one of lithium, sodium, potassium, calcium, magnesium, zinc, and aluminum metal sheets; the thickness of the counter / reference electrode is 0.2-0.5 mm.
5. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The lateral size of the single two-dimensional material nanosheet is -10-30 microns.
6. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The substrate is a stainless steel substrate or a Si / SiO2 substrate with a thickness of 0.2-0.5 cm, and a SiO2 layer thickness of 200-300 nm.
7. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The single two-dimensional material nanosheet may be prepared by chemical vapor deposition or chemical vapor transport.
8. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The conductive metal film may be any one of a copper film, a gold film and a platinum film, and may be realized by any one of evaporation and photolithography techniques.
9. The in-situ optical observation device for a single two-dimensional material nanosheet electrode according to claim 1, characterized in that: The electrode lead is at least one of copper wire, gold wire, silver wire, platinum wire and stainless steel wire, and the electrode lead is connected to the nanosheet electrode and the counter / reference electrode through conductive silver paste or soldering.
10. An in-situ optical observation method for a single two-dimensional material nanosheet electrode, characterized in that: The device described in any one of claims 1 to 9 is used for observation, and the specific steps are: connecting the two electrode leads of the device to the battery testing system respectively, and placing the device under an optical microscope, adjusting the focal length, and then applying current to perform constant current charge and discharge testing.