Electrode Material for Spin Capacitor, Spin Capacitor and Preparation Method Thereof

Abstract

Embodiments of the present application provide an electrode material for a spin capacitor, a spin capacitor, and a preparation method thereof. The electrode material includes transition metal nanoparticles derived from metal-organic frameworks. In the embodiments of the present application, the monodisperse metal-organic framework-derived transition metal nanoparticles have advantages such as small size, large specific surface area, and regular morphology, and the interfacial charge is sufficient to adsorb a large number of ions, thereby achieving an ideal spin specific capacity.

Description

[0001] This application claims the priority of the Chinese patent application filed with the China Patent Office on July 9, 2020, with application number 202010656576.9, and invention name “A nanocomposite material, preparation method, use method and device thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of spin electronic devices, and in particular to an electrode material for a spin capacitor, a spin capacitor and a preparation method thereof. Background Art

[0003] Electrode material is one of the key materials of spin capacitors, and its performance directly determines the performance of spin capacitors. Therefore, how to design electrode materials with better performance is a technical problem to be solved urgently in this field. Summary of the invention

[0004] The embodiments of the present application provide an electrode material for a spin capacitor, a spin capacitor and a preparation method thereof, so as to solve the problem of poor performance of the spin capacitor in the prior art.

[0005] In a first aspect, an embodiment of the present application provides an electrode material for a spin capacitor, characterized in that it includes a transition metal nanoparticle material derived from a metal organic framework.

[0006] Preferably, the transition metal is one or a combination of the following elements:

[0007] Iron, cobalt and nickel.

[0008] In a second aspect, an embodiment of the present application provides a spin capacitor, characterized in that it includes a first electrode, and the first electrode includes the electrode material described in any one of the first aspects.

[0009] Preferably, the device further comprises a second electrode, wherein the second electrode comprises lithium and / or a lithium metal compound.

[0010] Preferably, the lithium metal compound comprises one or a combination of the following compounds:

[0011] Lithium cobalt oxide, lithium iron phosphate, lithium nickel oxide.

[0012] Preferably, the spin capacitor is used to realize energy storage and / or spin information storage based on space charge.

[0013] In a third aspect, an embodiment of the present application provides a method for preparing a spin capacitor, characterized by comprising:

[0014] preparing a first electrode, the first electrode comprising transition metal nanoparticles derived from a metal organic framework;

[0015] Fabricate a second electrode, where the second electrode includes lithium and / or a lithium metal compound;

[0016] Assemble the first electrode and the second electrode into the spin capacitor according to any one of the second aspects.

[0017] Preferably, the fabrication of the first electrode includes:

[0018] Prepare a transition metal nanoparticle material derived from a metal-organic framework by a solvothermal method;

[0019] Fabricate a first electrode by using the transition metal nanoparticle material derived from the metal-organic framework.

[0020] In the embodiments of the present application, the monodisperse metal-organic framework-derived transition metal nanoparticles have advantages such as small size, large specific surface area, and regular morphology. The interfacial charge is sufficient to adsorb a large number of ions, thereby achieving an ideal spin specific capacity. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a scanning electron microscope image of an electrode material for a spin capacitor provided by an embodiment of the present application;

[0023] Figure 2 It is a preparation method of a spin capacitor provided by an embodiment of the present application;

[0024] Figure 3 It is an X-ray diffraction pattern of the metal-organic framework-derived transition metal nanoparticles prepared by an embodiment of the present application;

[0025] Figure 4 It is a magnetization curve of the metal-organic framework-derived transition metal nanoparticles prepared by an embodiment of the present application under a magnetic field of 30000 Oe;

[0026] Figure 5 It is a cyclic voltammogram curve of the spin capacitor prepared by an embodiment of the present application;

[0027] Figure 6 It is a constant current charge-discharge curve of the spin capacitor prepared by an embodiment of the present application. Detailed Embodiments

[0028] To enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0029] The spin capacitance effect originates from the formation of a double-layer capacitance between the spin charges and lithium ions at the ferromagnetic metal interface under the action of an electric field. This effect is the source of the additional capacity of transition metal compounds as electrode materials in energy storage devices. Storing charges through the ferromagnetic metal interface can effectively realize the application value in the two major fields of electrochemistry and magnetism, such as the design of energy storage devices, information reading, writing and storage, and the development of spintronic devices. In the field of electrochemistry, a large number of lithium ions adsorbed by the spin capacitance behavior can provide a large specific capacity, high energy density, high power density, long cycle life, and good rate performance. In the field of magnetism, with the action of an electric field, the accumulation / dissipation of charges at the ferromagnetic metal interface effectively affects the number and arrangement of spin electrons at the Fermi level of the 3d orbit, and thus the purpose of magnetic regulation can be achieved. This regulation method has the advantages of fast response speed, low energy consumption, non-volatility, stable reversibility and long life, and has great application value in new spintronic devices and information storage devices.

[0030] To realize the application value of spin capacitance in the above two major fields, the selection of ferromagnetic metal materials is very demanding. First of all, the ferromagnetic metal nanoparticles prepared by us have a small radius, no agglomeration phenomenon, regular morphology, and a large specific surface area. The spin capacitor device structure is reasonably designed to effectively avoid the surface cancellation effect.

[0031] Based on this, the embodiments of this application provide an electrode material for spin capacitance, a spin capacitance and its preparation method, which can store energy and spin information at high density and quickly at low voltage.

[0032] See Figure 1 , which is a scanning electron microscope image of an electrode material for spin capacitance provided by the embodiments of this application. The electrode material includes transition metal nanoparticles derived from metal-organic frameworks. Among them, the diameter of the transition metal nanoparticles is 3-7 nm.

[0033] In some possible implementation manners, the transition metal is one or a combination of the following elements: iron, cobalt, and nickel.

[0034] Corresponding to the above electrode material, the embodiments of this application also provide a spin capacitance, and the spin capacitance includes a first electrode and a second electrode. Among them, the first electrode includes Figure 1The electrode material shown; the second electrode includes lithium and / or a lithium metal compound. The lithium metal compound includes one or a combination of the following compounds: lithium cobaltate, lithium iron phosphate, lithium nickelate.

[0035] See Figure 2 , a method for preparing a spin capacitor provided by an embodiment of the present application. As Figure 2 shown, it mainly includes the following steps.

[0036] Step S201: Prepare a first electrode, and the first electrode includes transition metal nanoparticles derived from a metal-organic framework.

[0037] Specifically, metal-organic framework-derived transition metal nanoparticles can be prepared by a solvothermal method. Among them, the transition metal can be one or a combination of iron, cobalt, and nickel. Hereinafter, taking iron as the transition metal as an example for illustration.

[0038] Mix 4 mmol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 2.4 mmol of iron acetylacetonate (Fe(acac)3), add them to 30 mL of methanol and ultrasonicate for 30 minutes to form Solution 1. Add 16 mmol of 2-methylimidazole to 15 mL of methanol, stir magnetically until evenly mixed to form Solution 2. Dropwise add Solution 1 into Solution 2, stir magnetically for 1 hour to mix evenly, and then transfer it to a 60 mL sealed stainless steel autoclave with Teflon. Place the autoclave in a forced-air drying oven and heat it at 120 °C for 4 hours, and then cool it to room temperature. Centrifuge and wash the obtained mixture (8000 revolutions per minute, 4 minutes), first centrifuge and wash it 3 times with N,N-dimethylformamide, then centrifuge and wash it 2 times with methanol, and finally place it in a vacuum drying oven for drying at 70 °C for 12 hours.

[0039] Anneal the dried precursor in a tubular furnace under an Ar atmosphere, with the condition of heating to 900 °C at a rate of 5 °C per minute and holding for 3 hours, and then cooling to room temperature at a rate of 5 °C per minute. Then, heat it from Ar / H2 (Ar 95%, H2 5%) to 400 °C at a rate of 3 °C per minute and hold for 3 hours, and then cool it to room temperature at a rate of 4 °C per minute. Finally, obtain single-element Fe nanoparticles dispersed in the C-N organic framework.

[0040] In specific implementation, the metal-organic framework-derived transition metal nanoparticles: carbon black: CMC (sodium carboxymethyl cellulose) can also be ground and evenly coated on the current collector copper foil as the electrode material at a ratio of 7:2:1.

[0041] Step S202: Prepare a second electrode, where the second electrode includes lithium and / or a lithium metal compound.

[0042] Specifically, the lithium metal compound includes one or a combination of the following compounds: lithium cobaltate, lithium iron phosphate, and lithium nickelate.

[0043] Step S203: Assemble the first electrode and the second electrode into the spin capacitor according to any one of claims 3-5.

[0044] Charge and discharge the assembled spin capacitor within a preset voltage range (for example, 0.01-3V). Within this voltage range, the spin capacitor stores energy and / or spin information based on space charge, without the participation of an electrochemical reaction. Herein, the preset voltage range can be obtained through experimental tests or by other means, and the embodiments of the present application do not limit this.

[0045] In the embodiments of the present application, the monodisperse metal-organic framework-derived transition metal nanoparticles have advantages such as small size, large specific surface area, and regular morphology. The interfacial charge is sufficient to adsorb a large number of ions, thereby achieving an ideal spin specific capacity.

[0046] See Figure 3 , which is the X-ray diffraction pattern of the metal-organic framework-derived transition metal nanoparticles prepared in the embodiments of the present application. Herein, the transition metal is Fe. The X-ray diffraction pattern of the metal-organic framework-derived transition metal nanoparticles indicates that the material contains Fe and C, and the weaker diffraction peaks reflect a smaller nanoparticle scale, thereby having a higher specific surface area and achieving a higher energy density.

[0047] See Figure 4 , which is the magnetization curve of the metal-organic framework-derived transition metal nanoparticles prepared in the embodiments of the present application under a magnetic field of 30000 Oe. Herein, the transition metal is Fe.

[0048] See Figure 5 , which is the cyclic voltammogram of the spin capacitor prepared in the embodiments of the present application.

[0049] See Figure 6 , which is the galvanostatic charge-discharge curve of the spin capacitor prepared in the embodiments of the present application.

[0050] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0051] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0052] For the same or similar parts among the various embodiments in this specification, reference can be made to each other. In particular, for the terminal embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the descriptions in the method embodiments.

[0053] The above-described embodiments of the present application do not constitute a limitation to the protection scope of the present application.

Claims

1. A spin capacitor, characterized in that, Comprising: A first electrode, the first electrode comprising an electrode material, the electrode material comprising a transition metal nanoparticle material derived from a monodisperse metal-organic framework, the transition metal being one or a combination of the following elements: iron, cobalt, and nickel, the transition metal nanoparticle material derived from the monodisperse metal-organic framework being used for storing energy and / or spin information based on the spin capacitance effect of space charge storage, the monodisperse metal-organic framework being a C-N organic framework, and the diameter of the transition metal nanoparticles being 3-7 nm; A second electrode, the second electrode comprising lithium and / or a lithium metal compound.

2. The spin capacitor according to claim 1, wherein The lithium metal compound comprises one or a combination of the following compounds: Lithium cobaltate, lithium iron phosphate, lithium nickelate.

3. A method for preparing a spin capacitor, characterized in that, Comprising: Preparing a first electrode, the first electrode comprising an electrode material, the electrode material comprising a transition metal nanoparticle material derived from a monodisperse metal-organic framework, the transition metal being one or a combination of the following elements: iron, cobalt, and nickel, the transition metal nanoparticle material derived from the monodisperse metal-organic framework being used for storing energy and / or spin information based on the spin capacitance effect of space charge storage, the monodisperse metal-organic framework being a C-N organic framework, and the diameter of the transition metal nanoparticles being 3-7 nm; Preparing a second electrode, the second electrode comprising lithium and / or a lithium metal compound; Assembling the first electrode and the second electrode into the spin capacitor according to any one of claims 1-2.

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