阅读说明：本技术 纳米级锂硅合金材料及其制备方法和用途 (Nano-scale lithium-silicon alloy material and preparation method and application thereof ) 是由 罗飞 刘柏男 李泓 褚赓 黄学杰 陈立泉 于 2014-01-03 设计创作，主要内容包括：本发明公开了一种纳米级锂硅合金材料及其制备方法和用途,所述纳米级锂硅合金材料的组成包括：Li、Si以及掺杂元素；其中,Li和Si的摩尔比为1/100～5/1；所述纳米级锂硅合金材料中Li和Si的摩尔总含量大于等于90％；所述掺杂元素为B,P,Cu中的一种或多种；所述纳米级锂硅合金材料在任意一个维度上的尺寸为1nm至500nm。(The invention discloses a nanoscale lithium-silicon alloy material and a preparation method and application thereof, wherein the nanoscale lithium-silicon alloy material comprises the following components: li, Si and doping elements; wherein the molar ratio of Li to Si is 1/100-5/1; the total molar content of Li and Si in the nanoscale lithium-silicon alloy material is more than or equal to 90 percent; the doping element is one or more of B, P and Cu; the size of the nanoscale lithium-silicon alloy material in any dimension is 1nm to 500 nm.)

1. A nanoscale lithium silicon alloy material, wherein the nanoscale lithium silicon alloy material comprises the following components: li, Si and doping elements; wherein the molar ratio of Li to Si is 1/100-5/1; the total molar content of Li and Si in the nanoscale lithium-silicon alloy material is more than or equal to 90 percent; the doping element is one or more of B, P and Cu; the size of the nanoscale lithium-silicon alloy material in any dimension is 1nm to 500 nm;

the nanoscale lithium-silicon alloy material is prepared by the following method:

at room temperature, in an inert atmosphere, dissolving polycyclic aromatic compounds with the concentration of 0.01-5 mol/L in a first organic solvent to form a precursor solution;

adding metallic lithium into the precursor solution;

standing for 1-24 hours, and dissolving the metal lithium in the precursor solution to form a black or blackish green or light yellow lithiation solution; wherein, the lithium content in the lithiation solution is 0.001 g/L-100 g/L;

adding a nano silicon material or a doped nano silicon material into the lithiation solution, and continuously stirring for 5-100 hours to generate a lithium-silicon alloy suspension;

vacuum drying is carried out to prepare primary nano-scale lithium-silicon alloy powder;

and cleaning and filtering the primary nanoscale lithium-silicon alloy powder by using a second organic solvent, and drying in vacuum to obtain the nanoscale lithium-silicon alloy material.

2. The nanoscale lithium silicon alloy material according to claim 1, wherein the nanoscale lithium silicon alloy material is powder, and the specific morphology is one or more of spherical, ellipsoidal, linear, rhombic, conical, rod-like and irregular arbitrary polygon.

3. A method for preparing nanoscale lithium-silicon alloy material according to claim 1 or 2, characterized in that the method comprises:

at room temperature, in an inert atmosphere, dissolving polycyclic aromatic compounds with the concentration of 0.01-5 mol/L in a first organic solvent to form a precursor solution;

adding metallic lithium into the precursor solution;

standing for 1-24 hours, and dissolving the metal lithium in the precursor solution to form a black or blackish green or light yellow lithiation solution; wherein, the lithium content in the lithiation solution is 0.001 g/L-100 g/L;

adding a nano silicon material or a doped nano silicon material into the lithiation solution, and continuously stirring for 5-100 hours to generate a lithium-silicon alloy suspension;

vacuum drying is carried out to prepare primary nano-scale lithium-silicon alloy powder;

and cleaning and filtering the primary nanoscale lithium-silicon alloy powder by using a second organic solvent, and drying in vacuum to obtain the nanoscale lithium-silicon alloy material.

4. The method of claim 3, further comprising:

and heating the lithiation solution added with the nano silicon material or the doped nano silicon material while continuously stirring, wherein the heating temperature is 50-100 ℃.

5. The method according to claim 3, characterized in that said nano-silicon material is in particular: one or more of silicon nano-particles, silicon nano-tubes and silicon nano-sheets with the diameter of 1 nm-1000 nm.

6. The method of claim 5, wherein the diameter of the nano-silicon material is 20nm to 200 nm.

7. The method according to claim 3, wherein the continuous stirring is carried out for 10 to 48 hours.

8. The method according to claim 3, wherein the lithium metal is in particular one or more of lithium powder, lithium flakes, lithium rods, lithium strips, lithium foils.

9. The method according to claim 3, wherein the polycyclic aromatic compound is one or more of naphthalene, biphenyl, terphenyl, quaterphenyl, anthracene, phenanthrene, and derivatives thereof.

10. A method according to claim 3, wherein the first organic solvent is specifically one or more of dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether.

11. The method according to claim 3, wherein the second organic solvent is any one of N-methylpyrrolidone, benzene, toluene and xylene.

12. Use of the nanoscale lithium silicon alloy material according to claim 1 or 2 for the negative electrode material of thermal batteries, lithium ion capacitors, lithium air batteries, lithium sulfur batteries and all-solid-state batteries.

Technical Field

The invention relates to the field of materials science, in particular to a nanoscale lithium-silicon alloy material and a preparation method and application thereof.

Background

In the thermal battery, the anode of the thermal battery generally used at present mainly comprises Li-Al, Li-Si and Li-B alloy, wherein the Li-Al alloy is composed of a single solid solution phase containing 20 wt% of lithium, so that the discharge mechanism is simple and only shows a voltage plateau. The Li-Si alloy is an anode material with multiple discharge steps, and by utilizing the discharge characteristics of a Li-Si alloy multi-voltage platform, a plurality of voltage platforms can be utilized in the design of a thermal battery, so that the total capacity of the Li-Si alloy is larger than that of the Li-Al alloy, the large-current discharge capacity of the Li-Si alloy is strong, the electrode potential is lower than that of the Li-Al alloy, and the comprehensive performance of the Li-Si alloy is greatly superior to that of the Li-Al alloy. Therefore, the thermal battery using the lithium-silicon alloy as the cathode material has the advantages of large discharge power, high specific energy, rapid activation, long storage period, compact structure and the like compared with the calcium-system thermal battery system and the magnesium-system thermal battery system.

Meanwhile, in the current lithium ion battery, people are always searching for and developing a new high-capacity negative electrode material, wherein silicon material is a next generation lithium ion battery negative electrode material with great potential, and when the silicon negative electrode material is embedded with lithium, lithium and silicon can form a series of alloys, such as Li4.4Si, and the material has a theoretical capacity of 4200 mAh/g. However, the silicon negative electrode material has low first-cycle efficiency and low later-cycle efficiency, and a part of lithium can be doped into the silicon negative electrode material to form a part of lithium-silicon alloy, so that lithium lost in the formation of a Solid Electrolyte Interface (SEI) film in the lithium ion battery can be compensated, and the efficiency and the capacity of the lithium ion battery can be improved.

The currently commonly used lithium-silicon alloy is generally a lithium-silicon alloy with a micron-sized or more, and the preparation method mainly includes two methods, one is high-pressure preparation, for example, high-purity lithium powder and silicon powder are mixed according to a certain proportion and pressurized for 2 hours under 0.1 MPa; the other method is mainly that lithium powder and silicon powder are mixed evenly and then placed in a closed container to be sintered for 200 hours at 550 ℃. However, it should be noted that since the lithium-silicon alloy has very high activity, it needs to be prepared in a glove box filled with Ar gas, and the oxygen partial pressure is required to be strictly controlled to be less than 1ppm, and the water partial pressure is required to be less than 1ppm, so the preparation cost is high, the process is complicated, the yield is low, and the method is not suitable for large-scale manufacturing. The lithium-silicon alloy particles prepared by the two methods are relatively large and basically are more than micron-sized. If smaller sizes are required, an effective and safe preparation method has not been found. There are also few reports in the industry related to nano lithium silicon alloy materials.

Disclosure of Invention

The embodiment of the invention provides a nanoscale lithium-silicon alloy material and a preparation method and application thereof. The nanoscale lithium-silicon alloy material provided by the embodiment of the invention can be used as a negative electrode material of a thermal battery, a lithium ion capacitor, a lithium-sulfur battery, a lithium-air battery and an all-solid-state battery.

In a first aspect, embodiments of the present invention provide a nanoscale lithium silicon alloy material, where the nanoscale lithium silicon alloy material includes: li, Si and doping elements; wherein the molar ratio of Li to Si is 1/100-5/1; the total molar content of Li and Si in the nanoscale lithium-silicon alloy material is more than or equal to 90 percent; the doping element is one or more of B, P and Cu; the size of the nanoscale lithium-silicon alloy material in any dimension is 1nm to 500 nm.

Preferably, the nanoscale lithium-silicon alloy material is powder, and the specific shape of the nanoscale lithium-silicon alloy material is one or more of spherical, ellipsoidal, linear, rhombic, conical, rod-shaped and irregular arbitrary polygons.

In a second aspect, embodiments of the present invention provide a method for preparing a nanoscale lithium-silicon alloy material as described in the first aspect, where the method includes:

at room temperature, in an inert atmosphere, dissolving polycyclic aromatic compounds with the concentration of 0.01-5 mol/L in a first organic solvent to form a precursor solution;

adding metallic lithium into the precursor solution;

standing for 1-24 hours, and dissolving the metal lithium in the precursor solution to form a black or blackish green or light yellow lithiation solution; wherein, the lithium content in the lithiation solution is 0.001 g/L-100 g/L;

adding a doped nano silicon material into the lithiation solution, and continuously stirring for 5-100 hours to generate a lithium-silicon alloy suspension;

vacuum drying is carried out to prepare primary nano-scale lithium-silicon alloy powder;

and cleaning and filtering the primary nanoscale lithium-silicon alloy powder by using a second organic solvent, and drying in vacuum to obtain the nanoscale lithium-silicon alloy material.

Preferably, the method further comprises:

and heating the lithiation solution added with the doped nano silicon material while continuously stirring, wherein the heating temperature is 50-100 ℃.

Preferably, the nano silicon material is specifically: one or more of silicon nano-particles, silicon nano-tubes and silicon nano-sheets with the diameter of 1 nm-1000 nm.

More preferably, the diameter of the nano silicon material is 20nm to 200 nm.

Preferably, the continuous stirring time is 10-48 hours.

Preferably, the lithium metal is one or more of lithium powder, lithium sheet, lithium rod, lithium ribbon and lithium foil.

Preferably, the polycyclic aromatic compound is one or more of naphthalene, biphenyl, terphenyl, quaterphenyl, anthracene, phenanthrene and derivatives thereof.

Preferably, the first organic solvent is one or more of dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether and propylene glycol diethyl ether.

Preferably, the second organic solvent is specifically any one of N-methylpyrrolidone, benzene, toluene and xylene.

In a third aspect, embodiments of the present invention provide a use of the nanoscale lithium-silicon alloy material according to the first aspect, where the nanoscale lithium-silicon alloy material is used as a negative electrode material of a thermal battery, a lithium ion capacitor, a lithium air battery, a lithium sulfur battery, and an all-solid-state battery.

The nanoscale lithium-silicon alloy material provided by the embodiment of the invention has the advantages of nanoscale material size, simple and feasible preparation method, low cost and large-scale application, and can be used as a negative electrode material of a thermal battery, a lithium ion capacitor, a lithium-sulfur battery, a lithium-air battery and an all-solid-state battery.

Drawings

The technical solutions of the embodiments of the present invention are further described in detail with reference to the accompanying drawings and embodiments.

FIG. 1 is a flow chart of a method for preparing a nanoscale lithium-silicon alloy material according to example 2 of the present invention;

FIG. 2 is a scanning electron microscope image of a nanoscale lithium-silicon alloy material provided in example 3 of the present invention;

FIG. 3 is a Raman analysis graph of a nanoscale lithium-silicon alloy material provided in example 3 of the present invention;

FIG. 4 is a Raman analysis graph of a nanoscale lithium-silicon alloy material provided in example 4 of the present invention;

FIG. 5 is a Raman analysis graph of a nanoscale lithium-silicon alloy material provided in example 5 of the present invention;

fig. 6 is a raman analysis graph of the nano silicon powder provided in comparative example 1 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.

Examples 1 to 3, comparative examples 1 to 6

The embodiment 1 of the invention provides a nanoscale lithium-silicon alloy material, which comprises the following components: li, Si and doping elements; wherein the molar ratio of Li to Si is 1/100-5/1; the total molar content of Li and Si is greater than or equal to 50%; the doping elements are B, P and Cu, and the comparative examples 1-6 are C, N, F, Na, Mg and Al; the methods of comparative examples 1 to 6 are the same as those of example 1, except that the doping elements are different; the doping method specifically comprises the steps of introducing doping elements in the preparation process of the nano silicon; for example, when nano silicon is prepared by a ball milling method, magnesium oxide, copper oxide, boron oxide and the like are introduced, and the doping of the nano silicon is completed in repeated grinding; the silicon material can also be doped at high temperature by using a gas source containing N, F, P and the like, and then the nano-level doped silicon material is prepared.

The size of the nanoscale lithium-silicon alloy material in any dimension is 1nm to 500nm, and preferably 20nm to 200 nm.

The nano lithium silicon alloy material can be in a crystalline state or an amorphous state, is in a powder state, and can be in one or more of a regular shape such as a spherical shape, an ellipsoid shape, a linear shape, a rhombic shape, a conical shape, a rod shape and the like and a random polygon in a random irregular shape.

Preferably, the total molar content of Li and Si is greater than or equal to 95%.

The nanoscale lithium-silicon alloy material provided by the embodiment is a nanoscale powdery lithium-silicon alloy material, can be used as a negative electrode material of a thermal battery, a lithium ion capacitor, a lithium-sulfur battery, a lithium-air battery and an all-solid-state battery, and the battery using the nanoscale lithium-silicon alloy material as the negative electrode material has the characteristics of high discharge power, high specific energy, quick activation, long storage period, compact result and the like.

Selecting nano silicon doped with different elements as a raw material to prepare a doped nano lithium-silicon alloy according to the method disclosed by the patent;

firstly, evaluating the influence of different doping elements on the lithiation effect, secondly, assembling the obtained doped nano lithium-silicon alloy and metallic lithium into a button half cell, and testing the relative proportions of the reversible capacity at 0.1C, the first effect and the capacity at 3C, wherein the results are as follows:

TABLE 1

The results in table 1 show that the nano lithium-silicon alloy prepared by the preparation method of the invention has general first effect and improved rate capability; the comparison of the examples shows that the lithiation effect of the C, N and F elements is poor, so that the first effect of the material is not obviously improved, and the multiplying power is poor; the lithiation effect of three elements of Na Mg Al is good, the capacity is reduced after doping, but the conductivity of the material is improved by doping elements, and the rate capability is improved greatly; and the three elements B, Cu and P show the optimal comprehensive performance in the application of the nano lithium-silicon alloy.

Example 4

The present embodiment provides a method for preparing a nanoscale lithium-silicon alloy material, as shown in fig. 1, the method comprising:

step 101, at room temperature, in an inert atmosphere, dissolving a polycyclic aromatic compound with a concentration of 0.01 mol/L-5 mol/L in a first organic solvent to form a precursor solution;

specifically, the polycyclic aromatic compound is one or more of naphthalene, biphenyl, terphenyl, quaterphenyl, anthracene, phenanthrene and derivatives thereof; the first organic solvent is one or more of dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether and propylene glycol diethyl ether.

102, adding metal lithium into the precursor solution;

wherein, the metal lithium is one or more of lithium powder, lithium sheets, lithium rods, lithium tapes and lithium foils.

Step 103, standing for 1-24 hours, and dissolving the metal lithium in the precursor solution to form a black or dark green or light yellow lithiation solution; wherein, the lithium content in the lithiation solution is 0.001 g/L-100 g/L; preferably, the lithium content in the lithiation solution is 1 g/L-50 g/L.

104, adding a nano silicon material or a doped nano silicon material into the lithiation solution, and continuously stirring for 5-100 hours to generate a lithium-silicon alloy suspension;

specifically, in the process, the Li in the lithiation solution and the Si in the nano silicon material continuously perform an alloying reaction to generate a lithium-silicon alloy suspension.

Preferably, in one example, the lithiation solution added with the nano silicon material or the doped nano silicon material is heated while the stirring is continuously carried out, and the heating temperature can be 30-500 ℃, and preferably 50-100 ℃; the time of the alloying reaction is preferably 10 to 48 hours. The nano silicon material can be specifically as follows: one or more of silicon nanoparticles, silicon nanotubes and silicon nanosheets having a diameter of 1nm to 1000nm, preferably a diameter in the range of 20nm to 200 nm. The molar ratio of lithium in the lithiation solution to silicon in the added nano silicon material can be 100/1-2/1, and is further preferably 50/1-5/1. The alloying reaction speed of Li and Si is related to the size of added nano-silicon, the concentration of lithiated solution, the reaction temperature and the stirring speed. In addition, the lithiation solution is heated, so that the lithiation solution with high reaction activity can be obtained, and the alloying reaction time is shortened.

105, performing vacuum drying to prepare primary nano-scale lithium-silicon alloy powder;

and 106, cleaning and filtering the primary nanoscale lithium-silicon alloy powder by using a second organic solvent, and drying in vacuum to obtain the nanoscale lithium-silicon alloy material.

Specifically, the second organic solvent is any one of N-methylpyrrolidone, benzene, toluene, and xylene.

The preparation method of the nanoscale lithium-silicon alloy material provided by the embodiment can be used for preparing the nanoscale lithium-silicon alloy material with the size of 1nm to 500nm in any dimension, wherein the molar ratio of Li to Si is 1/100-5/1; the total molar content of Li and Si in the nanoscale lithium-silicon alloy material is more than or equal to 90 percent; by adjusting the concentration of the lithiation solution and the molar ratio of the lithium content in the lithiation solution to the nano-silicon, nano-scale lithium-silicon alloy materials with different lithiation degrees can be obtained. The method provided by the embodiment is simple and easy to implement, low in cost and suitable for application in large-scale manufacturing.

The following examples 6 to 7 illustrate the characteristics of nanoscale lithium-silicon alloy materials prepared by the method provided in example 2.

Example 5

Embodiment 5 of the present invention provides a first nanoscale lithium-silicon alloy material prepared by applying the preparation method of the nanoscale lithium-silicon alloy material described in embodiment 4, wherein the molar ratio of lithium and silicon in the lithiation solution and the added nanomaterial material is 5/1, the particle diameter of the nanomaterial material is 100nm, the alloying reaction time is 12 hours, and the reaction temperature is room temperature.

In this example, a scanning electron microscope photograph of the nano lithium silicon alloy material is shown in fig. 2. As can be seen from fig. 2, the particle diameter of the nano-scale lithium silicon alloy material prepared by the method for preparing the nano-scale lithium silicon alloy material in example 4 is between 100nm and 600nm, the nano-scale lithium silicon alloy material has a certain agglomeration, but the particle size is still maintained at the nano-scale.

Fig. 5 is a raman analysis graph of the nanoscale lithium-silicon alloy material of the present embodiment, as seen from fig. 3,the nano-scale lithium-silicon alloy material of the embodiment has a clear amorphization peak on a Raman spectrum, compared with the comparative example 1, except 520cm^-1Outside the crystalline peak of the silicon in the vicinity, at 480cm^-1An amorphous peak of silicon is obvious nearby, and 520cm is generated at the same time^-1The intensity of the nearby crystalline peak is significantly reduced, which indicates that lithium in the lithiation solution can indeed be intercalated into silicon, thereby causing an amorphizing lithiation reaction of silicon.

Example 6

Embodiment 6 of the present invention provides a second nanoscale lithium-silicon alloy material prepared by applying the preparation method of the nanoscale lithium-silicon alloy material described in embodiment 4, wherein the molar ratio of lithium and silicon in the lithiation solution and the added nanomaterial material is 5/1, the particle diameter of the nanomaterial material is 100nm, the alloying reaction time is 24 hours, and the reaction temperature is room temperature.

The Raman analysis result of the prepared nanoscale lithium-silicon alloy material is shown in FIG. 4, and as shown in FIG. 4, the Raman spectrum of the nanoscale lithium-silicon alloy material in example 4 has an obvious amorphization peak, compared with that of comparative example 1, except for 520cm^-1Outside the crystalline peak of the silicon in the vicinity, at 480cm^-1An amorphous peak of silicon is obvious nearby, and 520cm is generated at the same time^-1The strength of the nearby crystalline peak is significantly reduced, and unlike the nano lithium silicon alloy material in example 5, the strength of the amorphized peak of the nano lithium silicon alloy material in example 6 is stronger. Therefore, by prolonging the reaction time, more lithium will be incorporated into the silicon to form the nano lithium silicon alloy material.

Example 7

Embodiment 7 of the present invention provides a third nanoscale lithium-silicon alloy material prepared by applying the preparation method of the nanoscale lithium-silicon alloy material described in embodiment 4, wherein the molar ratio of lithium to silicon in the lithiation solution and the added nanomaterial material is 5/1, the particle diameter of the nanomaterial material is 100nm, the alloying reaction time is 12 hours, and the reaction temperature is 60 ℃.

The Raman analysis result of the prepared nanoscale lithium-silicon alloy material is shown in FIG. 5, and as shown in FIG. 5, the nanoscale lithium-silicon alloy material in example 5 is utilizedCompared with comparative example 8, the non-crystallization peak is obvious on the Raman spectrum of the grade lithium silicon alloy material except 520cm^-1Outside the crystalline peak of the silicon in the vicinity, at 480cm^-1An amorphous peak of silicon is obvious nearby, and 520cm is generated at the same time^-1The strength of the nearby crystalline peak is significantly reduced, and unlike the nano lithium silicon alloy material in example 5, the strength of the amorphized peak of the nano lithium silicon alloy material in example 7 is stronger. Therefore, by increasing the reaction temperature, more lithium will be incorporated into the silicon to form the nano lithium-silicon alloy material.

The following examples 8 to 10 illustrate the characteristics of nanoscale lithium-silicon alloy materials prepared by the method provided in example 2.

Example 8

Example 8 is presented to illustrate the dissolution rate of lithium metal powder of the present invention in the precursor solution described in example 4.

The dissolution rate is indicated as slow, medium, fast. The details of the dissolution are shown in Table 2.

TABLE 2

TABLE 1

Example 9

Example 9 is presented to illustrate the dissolution rate of lithium metal foil according to the present invention in the precursor solution described in example 4.

The dissolution rate is indicated as slow, medium, fast. The details of the dissolution are shown in Table 3.

TABLE 3

TABLE 2

Example 10

Example 10 is presented to illustrate the dissolution rate of lithium metal foil according to the present invention in the precursor solution described in example 4.

The dissolution rate is indicated as slow, medium, fast. The details of the dissolution are shown in Table 4.

TABLE 4

TABLE 3

Example 11

Example 11 is intended to illustrate the effects of nano-sized lithium silicon alloy materials prepared using different kinds of aromatic compounds and different kinds of organic solvents by applying the method of example 4 of the present invention.

The effect is expressed as poor, good, and some. The poor effect specifically means that the intensity of an amorphized peak of silicon in a Raman spectrum of the prepared nano lithium-silicon alloy material is lower than 500, the intensity of the amorphized peak in the effect is between 500 and 2000, and the effect preferably means that the intensity of the amorphized peak is higher than 2000.

The details of the effects are shown in Table 5.

TABLE 5

TABLE 4

Example 12

Embodiment 12 of the present invention provides a thermal battery prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1.

In this embodiment, the negative electrode material of the thermal battery is the nanoscale lithium-silicon alloy material provided in embodiment 1, the electrolyte of the thermal battery is a lithium chloride-potassium chloride eutectic, and the positive electrode is one of chromate, metal oxide or sulfide.

Example 13

Embodiment 13 of the present invention provides a lithium ion battery prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1.

In this embodiment, the negative electrode material of the lithium ion battery is in the nanometer scale as provided in embodiment 1A lithium silicon alloy material. The simulated cell was assembled in a glove box containing a high purity Ar atmosphere using lithium metal as the counter electrode and 1 mole of LiPF₆The solution in EC/DMC was used as electrolyte to assemble the cell. Constant current charge and discharge tests were carried out using a charge and discharge instrument manufactured by blue-electron limited, Wuhan City, with a discharge cut-off voltage of 0.005V and a charge cut-off voltage of 1V, at a current density of C/10.

Example 14

Embodiment 14 of the present invention provides a lithium ion battery prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1.

In this embodiment, the negative electrode material of the lithium ion battery is the nanoscale lithium-silicon alloy material provided in embodiment 1, the positive electrode is oxygen, and the electrolyte is an organic electrolyte containing lithium salt.

Example 15

Embodiment 15 of the present invention provides a lithium ion capacitor prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1.

In this embodiment, the negative electrode material of the lithium ion capacitor is the nanoscale lithium-silicon alloy material provided in embodiment 1.

Example 16

Embodiment 16 of the present invention provides a lithium-sulfur battery prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1 above.

In this embodiment, the negative electrode material of the lithium-sulfur battery is the nanoscale lithium-silicon alloy material provided in embodiment 1; the positive active substance comprises one or more of elemental sulfur, organic sulfide, porous carbon/sulfur composite material, polymer/sulfur composite material and lithium sulfide in any proportion; the conductive additive comprises any one of carbon black, carbon nanotubes and conductive graphite. The assembly of the simulated battery is carried out in a glove box containing high-purity Ar atmosphere, the nano-scale lithium-silicon alloy material is used as a counter electrode, and a solution of 5 moles of lithium bis (trifluoromethanesulfonate) imide (LiTFSI) in 1, 3-Dioxolane (DOL)/ethylene glycol dimethyl ether (DME) is used as an electrolyte to assemble the battery. And (3) carrying out a constant-current charge-discharge mode test by using a charge-discharge instrument, wherein the discharge cut-off voltage is 1V, the charge cut-off voltage is 3V, and the test is carried out under the current density of C/10.

Example 17

Embodiment 17 of the present invention provides an all-solid-state battery prepared based on the nanoscale lithium-silicon alloy material provided in embodiment 1 above.

In this embodiment, the negative electrode material of the all-solid battery is the nanoscale lithium-silicon alloy material provided in embodiment 1; the anode material is one or more of lithium iron phosphate, lithium cobalt oxide, lithium manganate, lithium nickelate, lithium manganite, ternary anode material and lithium iron phosphate, lithium cobalt oxide, lithium manganate, lithium nickelate, lithium manganite and ternary anode material with the surfaces coated with a carbon layer, a metal layer, a nitride layer, an oxide layer and a high polymer layer; the solid electrolyte is lithium titanium aluminum phosphate or doped lithium titanium aluminum phosphate.

Comparative example 7

The difference is no doping and lithiation as in example 1 of the present invention.

Comparative example 8

This comparative example is used to illustrate the performance of 100nm nanosilica prepared in a conventional manner (no doping, no lithiation).

The results of Raman analysis are shown in FIG. 6, and it can be seen from FIG. 6 that the Raman analysis is only at 520cm^-1Crystalline peaks of silicon appear nearby, and other miscellaneous peaks do not appear.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.