A nano-metal oxide lithium battery negative electrode material supported by layered silicate minerals and a preparation method thereof

Abstract

The present invention belongs to the technical field of lithium-ion battery electrode materials, and particularly relates to a lithium-ion battery anode material based on layered silicate minerals loaded with nano metal oxides and a preparation method thereof. The present invention selects exfoliated single-layer or few-layer layered silicate materials to deposit metal oxide nanoparticles. When the voltage is lower than 0.6V (vs. Li+ / Li), this material can in-situ construct a rich M / Li2O interface to achieve efficient utilization of interfacial charge storage. The specific preparation process includes: (1) exfoliating the layered silicate minerals to obtain single-layer or few-layer silicate materials; (2) dispersing the exfoliated layered silicate obtained in step (1) in water, adding a certain amount of soluble metal salts, and after continuous stirring and dissolution, adding a precipitating agent for precipitation; (3) separating and drying the above-mentioned precipitate, and then performing high-temperature annealing and sintering. The method provided by the present invention helps to achieve energy density and power density, and has simple steps, does not require special equipment and harsh reaction conditions, and is easy to prepare industrially.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion battery electrode materials, and specifically relates to a metal oxide lithium battery negative electrode material supported by a layered silicate mineral and a preparation method thereof. Background Art

[0002] Rechargeable lithium-ion batteries are widely used in portable electronic devices, such as smartphones, tablets, laptops and other consumer electronic products. In recent years, with the development of the electric vehicle industry, the application of lithium-ion batteries has been further expanded. However, despite the increasing demand for lithium-ion batteries, the development of lithium-ion battery technology is relatively slow compared to the development of the electronics industry. In fact, the battery life of current portable consumer electronics and pure electric vehicles has been unsatisfactory and needs to be further improved, which depends on the improvement of lithium-ion battery performance. Electrode materials play a decisive role in the performance of lithium-ion batteries. Electrode materials with excellent performance are the basis of high-performance lithium-ion batteries. In fact, the negative electrode materials of commercial lithium-ion batteries are mainly graphite (natural graphite, artificial graphite, and mesophase carbon microspheres, etc.). In addition, silicon-carbon composite materials and lithium titanate also have certain applications. Although the cycle stability of graphite negative electrode materials is good and the cycle life can reach more than 500 times, its theoretical specific capacity is only 372mA hg -1 , and its rate performance is poor. However, fast charging has important practical significance in the fields of mobile electronic devices and electric vehicles. The layered structure of the graphite negative electrode makes its rate performance relatively limited and difficult to meet actual needs. Lithium titanate (Li4Ti5O 12 ) has a volume change of only 0.20% before and after lithium insertion, and is called a "zero strain" material, so it has good cycle stability, is non-flammable, and has good safety. At the same time, lithium titanate crystals have a three-dimensional pore structure, which is conducive to the rapid diffusion of lithium ions, and its charge and discharge platform is as high as 1.55V (vs.Li + / Li), avoiding the formation of SEI film, which is beneficial to improve the first cycle coulombic efficiency. However, since only about 60% of titanium (IV) can be reduced, its theoretical specific capacity (175mA hg -1 ) is low, and the high working voltage makes the output voltage of the whole battery low, thus limiting the application of lithium titanate batteries. Therefore, it is urgent to develop new electrode materials with high energy density and high power density.

[0003] As early as 1972, Exxon et al. proposed to use TiS2 as the positive electrode, metal lithium as the negative electrode, and lithium perchlorate dissolved in dioxolane as the electrolyte to construct a metal lithium battery. However, when metal lithium is used as the negative electrode, it is easy to cause dendrite growth and form dead lithium after melting. This not only makes the cycle stability of lithium metal batteries poor and the capacity retention rate low, but also has serious safety hazards. Subsequently, in the late 1970s and 1980s, Murphy et al. and Scrosati et al. successively proposed and improved the "rocking chair model", that is, using materials with lower lithium insertion / de-lithium potential as the negative electrode, and materials with higher lithium insertion / de-lithium potential as the positive electrode, and lithium ions migrate between them like a rocking chair. Thereafter, in 1989, Sony Corporation of Japan first proposed to use lithium cobalt oxide as the positive electrode, petroleum coke as the negative electrode, and lithium hexafluorophosphate dissolved in propylene carbonate and ethylene carbonate as the electrolyte to develop a new type of lithium-ion battery, and successfully commercialized it in 1991. Compared with traditional secondary batteries such as nickel-cadmium batteries and nickel-metal hydride batteries, lithium-ion batteries have high open circuit voltage (>3.6V) and high energy density (120-150W h kg -1 ), no memory effect and long working life, so it quickly replaced the traditional secondary battery and was widely used in portable electronic devices such as smart phones, tablets, laptops and military equipment (such as submarines). With the development of mobile Internet, electric vehicles and large-scale energy storage in power grids, the energy density, power density, cycle stability and safety of lithium-ion batteries are increasingly difficult to meet actual needs. Therefore, it is urgent to develop a new generation of high-performance lithium-ion batteries.

[0004] Carbon materials, especially hard carbon negative electrode materials, have high specific capacity and good cycle stability, but are limited by their low first-cycle coulombic efficiency and limited rate performance and cannot be put into practical use. The low first-cycle coulombic efficiency is mainly attributed to the side reaction with the electrolyte (forming SEI) and the side reaction of adsorbed impurities with the electrolyte. Silicon, as an alloy negative electrode material, has a high specific capacity of 4200mA hg -1 (Li 4.4 Si), and its charge and discharge voltage platform is lower than that of transition metal oxides, about 0.20V (vs.Li + / Li), and thus has received widespread attention. However, similar to transition metal oxides, its intrinsic electronic conductivity and ionic conductivity are both poor, and there is a volume change of up to 400% when fully embedded with lithium. Similarly, in order to solve these difficulties that hinder its practical application, the current method is to nano-size silicon and use carbon materials to coat it or disperse it in a carbon matrix, which has the same problem of difficulty in practical application as transition metal oxides. Transition metal oxides MO x(Advanced Functional Materials, 2015, 25, 1082-1089) can be used as negative electrode materials, and its specific capacity is much higher than that of commercial graphite negative electrodes. However, since the electronic conductivity and lithium ion transmission capacity of transition metal oxides are generally poor, and there is a large volume expansion when they are fully embedded with lithium (for example, the volume expansion of Fe2O3 reaches ~100% after complete lithium embedding). To solve these problems, the strategy of nano-sizing transition metal oxides and introducing carbon materials is currently adopted to improve the cycle stability and rate performance of the materials, and significant results have been achieved. Due to the reduction in the size of transition metal oxides after nano-sizing, the distance for lithium ion and electron migration and diffusion is significantly shortened, which is conducive to buffering volume changes. At the same time, after the introduction of carbon materials to disperse transition metal oxides, not only the electronic conductivity of the material is greatly improved, but the carbon material itself has a certain flexibility and structural strength, which is conducive to further relieving the stress caused by volume changes, thereby significantly improving the cycle stability and rate performance of the material. However, its charge and discharge voltage platform is relatively high. To obtain an energy density equivalent to that of carbon materials, its specific capacity must be much higher than that of carbon materials. In fact, the stable specific capacity of transition metal oxides is usually less than 1000 mA h g -1 , and the rate performance is relatively limited and cannot meet the requirements of practical applications. Summary of the invention

[0005] Based on the problems existing in carbon-based negative electrode materials, silicon-based negative electrode materials or composites of the above materials when used as energy storage materials, the present invention provides a nano metal oxide lithium battery negative electrode material loaded with layered silicate minerals and a preparation method thereof.

[0006] The purpose of the present invention is to provide a method for preparing a lithium-ion battery electrode material with ultra-high capacity, fast charge and discharge and good safety performance at low cost. The preparation method provided by the present invention aims to solve the problem of low specific capacity and poor electrochemical performance, especially rate performance, of electrode materials (especially negative electrode materials) in current research.

[0007] The present invention is implemented as follows: In order to achieve ultra-high specific capacity and realize higher energy density than carbon materials, abnormal charge storage such as interfacial charge storage in metal oxide negative electrodes is crucial. Interfacial charge storage involves the interface between the metal and the lithium salt formed in situ, namely M / Li2O. Reasonable utilization will help to achieve ultra-high specific capacity far exceeding the theoretical capacity of the conversion mechanism. In the present invention, in order to construct as many M / Li2O interfaces as possible, we selected a single layer or a few layers of layered silicate materials after exfoliation to deposit metal oxide nanoparticles. Due to the similar oxygen atom stacking mode, there is a strong interaction between metal oxides and layered silicate minerals. When used as negative electrode materials for lithium ion batteries, the metal oxide particles do not agglomerate and coarsen after electrochemical cycles. Therefore, when the voltage is lower than 0.6V (vs.Li+ / Li), a rich M / Li2O interface can be constructed in situ to achieve efficient utilization of interfacial charge storage and achieve ultra-high capacity far exceeding the theoretical capacity.

[0008] The specific preparation process of the nano-metal oxide lithium battery negative electrode material supported by layered silicate minerals comprises the following steps: exfoliating the layered silicate minerals to obtain a single-layer or few-layer silicate material; dispersing the exfoliated layered silicate obtained in step (1) in water, adding a certain amount of the soluble salt of the metal, stirring and dissolving it continuously, and then adding a precipitant for precipitation; separating and drying the above precipitate, and then annealing and sintering it at high temperature. Among them, the stripping of layered silicate minerals can be carried out by mechanical stripping, chemical stripping, electrochemical stripping or a combination of several thereof; the metal element can be one or several of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, tin and other elements, among which iron, cobalt, nickel, copper and a combination thereof are preferred; during sintering, the annealing temperature is 300-1200°C, and the holding time of the annealing process is 0.5-24 hours, among which the annealing temperature is preferably 400-800°C, and the holding time is 1-8 hours; during high-temperature annealing, an inert atmosphere (a combination of one or more of He, Ne, Ar, N2), an oxidizing atmosphere (a combination of one or more of air and O2) or a reducing atmosphere (a combination of one or more of H2 and an inert atmosphere) can be used according to the type of oxide.

[0009] Compared with the existing technology, the layered silicate mineral-loaded nano-metal oxide lithium battery negative electrode material and the preparation method thereof designed in the present invention have the following advantages:

[0010] The introduction of carbon materials is avoided, and this negative electrode material is able to achieve a higher tap density, which is conducive to achieving a higher volume energy density. At the same time, it is non-flammable, which is conducive to further improving the safety of lithium-ion batteries and promoting the development of the new energy vehicle industry. The metal oxide particle size loaded on the layered silicate mineral is relatively small, which greatly shortens the lithium ion diffusion distance and the electron transmission distance in the electrochemical process, and achieves excellent rate performance. In addition, the layered silicate mineral is a natural product, which only requires simple peeling, and the reserves of metal oxides, especially iron oxide, are also very abundant, so the materials and preparation methods designed by the present invention have the advantages of low cost, simple process, and ease of industrialization.

[0011] Sample characterization

[0012] The morphology and ultrastructure information of the samples were collected using a scanning electron microscope and a transmission electron microscope, the structure information of the samples was collected using an X-ray diffractometer, the pore structure information of the samples was collected using a specific surface area tester, the conductivity of the samples was measured using a comprehensive physical property measurement system, and the electrode performance of the samples was characterized using a blue battery test system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A transmission electron microscope photograph of a nano-iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention is shown;

[0014] Figure 2 A high-resolution transmission electron microscope photograph of a nano-iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention is shown;

[0015] Figure 3 A nitrogen isothermal adsorption and desorption diagram of a nano-iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention is shown;

[0016] Figure 4 The cyclic voltammogram of the nano iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention is shown;

[0017] Figure 5 A cycle performance diagram showing a nano iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention;

[0018] Figure 6 The figure shows the rate performance of the nano iron oxide negative electrode material loaded on vermiculite prepared according to the method of the present invention. DETAILED DESCRIPTION

[0019] In order to further illustrate the content, characteristics and practical effects of the present invention, the present invention is described in detail below in conjunction with embodiments. It should be pointed out that the modification method of the design of the present invention is not limited to these specific embodiments. Without departing from the spirit and connotation of the design of the present invention, the equivalent replacement and modification performed by those skilled in the art on the basis of reading the content of the present invention are also within the scope of the present invention.

[0020] Implementation Example 1:

[0021] A nano-iron oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite ultrasonically stripped with a hydrogen peroxide solution and 2.70 g of ferric chloride hexahydrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 8 mL of concentrated ammonia water (28%) to the above liquid. After continuing to stir for 6 hours, centrifuge the precipitate, wash it three times with deionized water, and then freeze-dry it in vacuum. The powder sample collected after freeze-drying is placed in a corundum boat, and the corundum boat is placed in a tubular furnace. Under the protection of a high-purity Ar atmosphere, the temperature is first raised to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0022] The sample obtained after annealing is the nano-iron oxide negative electrode material loaded on vermiculite. The electrochemical performance of this negative electrode material was evaluated using a CR2016 button cell. The button cell negative electrode is a metal lithium sheet with a thickness of 1 mm and a diameter of 15 mm. The positive electrode is composed of the nano-iron oxide negative electrode material loaded on vermiculite in Example 1, conductive acetylene black, and binder polyvinylidene fluoride (PVDF), with a mass ratio of 8:1:1. The specific preparation process of the positive electrode is as follows: first take 0.16g of the iron oxide negative electrode material loaded on vermiculite, 0.02g of conductive acetylene black, and 1mL of PVDF N-2 methylpyrrolidone solution (20mg / mL), and prepare a slurry after stirring. The slurry is then coated on a copper foil, dried at 120°C in a vacuum oven, and then cut into electrode sheets with a diameter of 14 mm using a stamping die. On the positive electrode sheet, the loading amount of active material is 1 to 1.5mg / cm 2 When assembling the battery, a glass fiber separator from Whatman was used, 1M lithium hexafluorophosphate electrolyte (the mass ratio of the solvent in the solvent was EC:DMC=1:1), and the assembly was performed in a glove box. During assembly, oxygen and water vapor were both below 1ppm. The electrochemical test was performed using the CHI760e electrochemical workstation from Shanghai Chenhua and the LAND-CT2001C battery test system from Blue Electric.

[0023] Implementation Example 2:

[0024] A nano copper oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution and 1.88 g of copper nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0025] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0026] Implementation Example 3:

[0027] A nano nickel oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution and 1.83 g of nickel nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0028] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0029] Implementation Example 4:

[0030] A nanometer cobalt oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution and 1.83 g of cobalt nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0031] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0032] Implementation Example 5:

[0033] A nano manganese oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution and 1.79 g of manganese nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0034] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0035] Implementation Example 6:

[0036] A nano manganese oxide copper oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of manganese nitrate, and 1.0 g of copper nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0037] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0038] Implementation Example 7:

[0039] A nano-iron oxide copper oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of iron nitrate, and 1.0 g of copper nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 10 mL of NaOH (5 mol L -1). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0040] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0041] Implementation Example 8:

[0042] A nano zinc oxide negative electrode material loaded on vermiculite and a preparation method thereof. 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution and 0.79 g of zinc nitrate were weighed and then placed in a 100 mL beaker. 50 mL of deionized water was added to the beaker and ultrasonicated for 30 minutes. Then, 20 mL of LiOH (2 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0043] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0044] Implementation Example 9:

[0045] A nano zinc oxide copper oxide negative electrode material loaded on vermiculite and a preparation method thereof. 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of zinc nitrate, and 1.0 g of copper nitrate are weighed, and then placed in a 100 mL beaker, and 50 mL of deionized water is added to the beaker, and ultrasonicated for 30 minutes. Then, 30 mL of LiOH (2 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0046] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0047] Implementation Example 10:

[0048] A nano zinc oxide manganese oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of zinc nitrate, and 1.0 g of manganese nitrate, then place them together in a 100 mL beaker, add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 30 mL of LiOH (2 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0049] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0050] Implementation Example 11:

[0051] A nano nickel oxide manganese oxide negative electrode material loaded on vermiculite and a preparation method thereof. 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of nickel nitrate, and 1.0 g of manganese nitrate are weighed, and then placed in a 100 mL beaker, and 50 mL of deionized water is added to the beaker, and ultrasonicated for 30 minutes. Then, 30 mL of LiOH (2 mol L -1 ). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0052] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

[0053] Implementation Example 12:

[0054] A nanometer cobalt oxide manganese oxide negative electrode material loaded on vermiculite and a preparation method thereof. Weigh 1.5 g of vermiculite after ultrasonic peeling with hydrogen peroxide solution, 0.79 g of cobalt nitrate, and 1.0 g of manganese nitrate, and then put them together in a 100 mL beaker, and add 50 mL of deionized water to the beaker, and ultrasonicate for 30 minutes. Then, under continuous electromagnetic stirring, add 30 mL of LiOH (2 mol L -1). After stirring for 6 hours, the precipitate was centrifuged and washed three times with deionized water, and then freeze-dried in vacuum. The powder sample collected after freeze-drying was placed in a corundum boat, and the corundum boat was placed in a tube furnace. Under the protection of high-purity Ar atmosphere, the temperature was first increased to 900°C at a rate of 5°C / min, and kept at this temperature for 4 hours, and then naturally cooled to room temperature.

[0055] The electrochemical performance evaluation of this negative electrode material is the same as that of Example 1.

Claims

1. A nano-metal oxide lithium battery negative electrode material supported by a layered silicate mineral, characterized in that: 1) The layered silicate mineral is a single-layer or few-layered silicate material after exfoliation, and the number of layers does not exceed 30; 2) The metal oxide supported on the layered silicate mineral is small in size, and the diameter of a single metal oxide particle is within 200 nm; 3) The metal oxide has a strong interaction with the layered silicate mineral, and when used as a negative electrode material for a lithium-ion battery, the metal oxide particles do not agglomerate and coarsen after electrochemical cycles; 4) Ultrafine metal oxide particles at a voltage lower than 0.6V vs.Li + / Li, a rich metal / Li2O interface can be constructed in situ, realizing efficient utilization of interfacial charge storage and achieving an ultra-high capacity far exceeding the theoretical capacity.

2. The layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 1, characterized in that: The layered silicate mineral is one or a combination of muscovite, biotite, kaolinite, talc, montmorillonite, vermiculite, serpentine, palygorskite and pyrophyllite.

3. The layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 2, characterized in that: The layered silicate minerals are vermiculite, muscovite, montmorillonite, serpentine and combinations thereof.

4. The layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 1, characterized in that: The metal element in the metal oxide is one or more of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc and tin.

5. The layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 4, characterized in that: The metal elements in the metal oxide are iron, cobalt, nickel, copper and combinations thereof.

6. The layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 1, characterized in that: The mass ratio of the metal oxide to the layered silicate mineral is 0.05-5.0:1.

0.

7. The method for preparing a nano-metal oxide lithium battery negative electrode material supported by a layered silicate mineral according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) exfoliating the layered silicate mineral to obtain a single-layer or few-layer silicate material; 2) dispersing the exfoliated layered silicate obtained in step (1) in water, adding a certain amount of soluble salt of the metal element in the metal oxide, stirring and dissolving, and then adding a precipitant for precipitation; 3) The precipitate obtained after the precipitation is separated and dried, and then annealed and sintered at high temperature.

8. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: The stripping of the layered silicate mineral is carried out by mechanical stripping, chemical stripping, electrochemical stripping or a combination of the two.

9. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: The precipitant is one or a combination of ammonia water, lithium hydroxide, sodium hydroxide and potassium hydroxide.

10. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: During high temperature annealing, an inert atmosphere, an oxidizing atmosphere or a reducing atmosphere can be used depending on the type of metal oxide; the inert atmosphere is one or a combination of two or more of He, Ne, Ar, and N2; the oxidizing atmosphere is one or a combination of two or more of air and O2; the reducing atmosphere is H2 and a combination of one or more of H2 and an inert atmosphere.

11. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: The annealing temperature during the high temperature annealing is 300-1200° C., and the annealing process heat preservation time is 0.5-24 hours.

12. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: During the high temperature annealing, the heating rate is 1-20°C / min.

13. The method for preparing the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material according to claim 7, characterized in that: The particle size of the metal oxide is related to the loading amount and the particle size is between 10 nanometers and 300 nanometers.

14. Application of the nano-metal oxide lithium battery negative electrode material supported by the layered silicate mineral according to any one of claims 1 to 6 in lithium ion batteries, sodium ion batteries, potassium ion batteries and supercapacitors.

15. The use of the layered silicate mineral-supported nano-metal oxide lithium battery negative electrode material in lithium ion batteries, sodium ion batteries, potassium ion batteries and supercapacitors according to claim 14, characterized in that: When it is applied to sodium ion batteries, potassium ion batteries and supercapacitors, the metal oxide particle size should be controlled within a range of 10 nanometers to 50 nanometers.

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