A silicon monoxide nanomaterial and a preparation method thereof

Abstract

The present invention discloses a silicon monoxide nanomaterial and a preparation method thereof, belonging to the technical field of nanomaterials. The silicon monoxide nanomaterial comprises the following raw materials in parts by weight: metal silicon powder: 80 - 120 parts, silicon dioxide powder: 20 - 40 parts, binder: 0.5 - 3 parts, surfactant: 2 - 8 parts; in the present invention, intermediate 1 is prepared by the substitution reaction of 3 - allyl - 2 - hydroxybenzaldehyde and epichlorohydrin, then intermediate 2 is prepared by the ring - opening reaction of intermediate 1 and n - decanol, then intermediate 3 is prepared by the sulfonation reaction of intermediate 2 and 1,3 - propane sultone, and finally the surfactant is prepared by the polymerization reaction of 2 - methacryloyloxyethyl phosphorylcholine, 2 - acrylamide - 2 - methylpropanesulfonic acid and intermediate 3. The silicon monoxide nanomaterial prepared by the present invention has a high initial Coulomb efficiency and good cycle performance.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and particularly relates to a silicon monoxide nanomaterial and a preparation method thereof. Background Art

[0002] Due to outstanding advantages such as no memory effect, excellent cycle life, high working voltage, and high energy density, lithium-ion batteries have developed rapidly in the 21st century and are widely used in portable devices and energy storage systems. The current anodes used in lithium-ion batteries, such as graphite, lithium titanate, and tin-based materials, respectively have disadvantages such as voltage hysteresis, low capacity, and low power, making it difficult to meet the social development's demand for high energy density and high power density batteries.

[0003] Among numerous new electrode materials, silicon materials are considered to be one of the most promising anode active materials for next-generation advanced rechargeable lithium-ion batteries. Compared with commercial graphite, silicon anodes have many advantages, such as an extremely high theoretical specific capacity, an ideal electrochemical lithiation / delithiation potential plateau, and the fact that silicon, as the most abundant element in the earth's crust, can reduce manufacturing costs. The theoretical capacity of silicon monoxide is 2800 mAh g -1 , although it is lower compared to pure silicon, the lithium silicate and Li2O formed during the first lithium insertion process can buffer volume changes, thereby improving cycle stability. However, silicon monoxide also has several drawbacks that cannot be ignored. First, silicon monoxide is an insulator with low intrinsic conductivity; second, silicon monoxide will irreversibly form Li2O and lithium silicate during the first cycle, resulting in a relatively low first Coulombic efficiency of silicon monoxide. Therefore, it is urgent to develop a silicon monoxide material with good electrical conductivity and high first Coulombic efficiency.

[0004] The Chinese invention patent with the publication number CN115028169A discloses a preparation method of a porous silicon monoxide anode material for lithium-ion batteries. Although the porous silicon monoxide anode material prepared by the method of this patent has an excellent first discharge specific capacity, its cycle performance is poor. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a silicon monoxide nanomaterial and a preparation method thereof.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] A silicon monoxide nanomaterial, comprising the following raw materials in parts by weight:

[0008] Metallic silicon powder: 80 - 120 parts,

[0009] Silicon dioxide powder: 20 - 40 parts,

[0010] Binder: 0.5 - 3 parts,

[0011] Surfactant: 2 - 8 parts;

[0012] The surfactant is prepared by the following method:

[0013] S1: Under nitrogen protection, add DMSO, 3 - allyl - 2 - hydroxybenzaldehyde, and epichlorohydrin into the reactor, stir and mix evenly, heat up to 70 - 80 °C, add the catalyst TEBAC, continue to heat up to 100 - 120 °C, react for 6 - 10 h, cool down to 50 - 60 °C, then add KOH, continue to react for 4 - 6 h, and perform post - treatment to obtain intermediate 1. The reaction equation is shown as follows:

[0014]

[0015] S2: Under nitrogen protection, add tetrahydrofuran, intermediate 1, and n - decanol into the reactor, stir and mix evenly, heat up to 80 - 100 °C, then add sodium hydride, react for 8 - 12 h, and perform post - treatment to obtain intermediate 2. The reaction equation is shown as follows:

[0016]

[0017] S3: Under nitrogen protection, add tetrahydrofuran, intermediate 2, and 1,3 - propane sultone into the reactor, stir and mix evenly, then add sodium hydride, heat up to 50 - 90 °C and react for 10 - 12 h, and perform post - treatment to obtain intermediate 3. The reaction equation is shown as follows:

[0018]

[0019] S4: Under nitrogen protection, add tetrahydrofuran, intermediate 3, 2 - methacryloyloxyethyl phosphorylcholine, and 2 - acrylamido - 2 - methylpropanesulfonic acid into the reactor, heat up to 70 - 80 °C and react for 20 - 30 min, then add the initiator AIBN, and react at 100 - 120 °C for 16 - 24 h. The reaction equation is shown as follows:

[0020]

[0021] Wherein, m, n, and r are natural numbers.

[0022] In step S1, the feeding mass ratio of DMSO, 3 - allyl - 2 - hydroxybenzaldehyde, KOH, and epichlorohydrin is 100:(6 - 8):(1 - 5):(15 - 20).

[0023] In step S2, the feeding mass ratio of intermediate 1 and n - decanol is (15 - 20):(12 - 18).

[0024] In step S3, the feeding mass ratio of tetrahydrofuran, intermediate 2, and 1,3 - propane sultone is 50:(6 - 8):(12 - 15).

[0025] In step S4, the feeding mass ratio of tetrahydrofuran, intermediate 3, 2 - methacryloyloxyethyl phosphorylcholine, and 2 - acrylamido - 2 - methylpropanesulfonic acid is 50:(5 - 10):(6 - 12):(10 - 14).

[0026] The binder is one of sodium carboxymethyl cellulose and polyacrylic acid.

[0027] A preparation method of silicon monoxide nanomaterial, comprising the following steps:

[0028] S1: Weigh by parts by weight: 80 - 120 parts of metallic silicon powder, 20 - 40 parts of silicon dioxide powder, 0.5 - 3 parts of binder, and 2 - 8 parts of surfactant;

[0029] S2: Add the surfactant into absolute ethanol and deionized water, and stir at 40 °C for 30 min to make the solution evenly mixed;

[0030] S3: Add the silicon dioxide powder and metallic silicon powder into a mixer and stir - mix. After mixing evenly, add the binder and the surfactant solution, continue stirring, place the fully - mixed material in a press to be pressed into sheets, and then dry;

[0031] S4: Put the dried raw material sheet into a vacuum sintering furnace, carry out a negative - pressure high - temperature reaction. After the reaction ends, stop heating, fill nitrogen into the vacuum sintering furnace for cooling, cool the furnace temperature to 200 °C, and then naturally cool to room temperature to obtain the silicon monoxide nanomaterial.

[0032] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0033] (1) In the present invention, 3 - allyl - 2 - hydroxybenzaldehyde and epichlorohydrin are used to prepare intermediate 1 through a substitution reaction, then intermediate 1 and n - decanol are used to prepare intermediate 2 through a ring - opening reaction, then intermediate 2 and 1,3 - propane sultone are used to prepare intermediate 3 through a sulfonation reaction, and finally 2 - methacryloyloxyethyl phosphorylcholine, 2 - acrylamido - 2 - methylpropanesulfonic acid and intermediate 3 are used to prepare the surfactant through a polymerization reaction.

[0034] (2) The surfactant prepared by the present invention has amphiphilic groups. When it reaches a certain concentration in water, it will first form rod-like micelles, with the hydrophobic groups facing inwards and the hydrophilic group heads extending into the water. When the concentration of the surfactant in water reaches a certain value, these rod-like micelles will regularly arrange into a hexagonal ordered liquid crystal structure. During the preparation of the nanomaterial, the silicon source and the surfactant can have an electrostatic interaction. During the formation of mesoporous silicon monoxide, the silicon source and the surfactant cation interact with the hydrophilic end of the micelle through electrostatic interaction, causing the silicon source to hydrolyze and finally polymerize and precipitate on the columnar micelles of the surfactant, forming an inorganic pore wall. After removing the surfactant, a porous silicon monoxide material can be obtained. Since there are many pores on the surface of the silicon monoxide material, it can well relieve the volume expansion generated during the lithium insertion process, thereby prolonging the cycle life of the battery. Detailed implementation mode

[0035] The following is further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0036] Example 1 Preparation of surfactant:

[0037] S1: Under nitrogen protection, 1 kg of DMSO, 60 g of 3-allyl-2-hydroxybenzaldehyde, and 150 g of epichlorohydrin were added to the reactor, stirred and mixed evenly, heated to 70 °C, 6 g of catalyst TEBAC was added, and then heated to 100 °C and reacted for 10 h. The temperature was lowered to 50 °C, then 10 g of KOH was added, and the reaction continued for 6 h. Vacuum distillation was carried out at 70 °C for 40 min, and vacuum drying was carried out at 60 °C for 5 h to obtain Intermediate 1.

[0038] S2: Under nitrogen protection, 280 g of tetrahydrofuran, 150 g of Intermediate 1, and 120 g of n-decanol were added to the reactor, stirred and mixed evenly, heated to 80 °C, then 5 g of sodium hydride was added, and the reaction was carried out for 12 h. 15 ml of 37 wt% hydrochloric acid was added to neutralize the reaction mixture, then 300 ml of ether and 300 ml of deionized water were added for extraction, dried with 80 g of anhydrous sodium sulfate, filtered, rotary evaporated at 60 °C for 1 h to obtain the crude product, and then recrystallized in 500 ml of ether and vacuum dried at 70 °C for 6 h to obtain Intermediate 2.

[0039] S3: Under nitrogen protection, 500 g of tetrahydrofuran, 60 g of Intermediate 2, and 120 g of 1,3-propane sultone were added to the reactor, stirred and mixed evenly, then 6 g of sodium hydride was added, heated to 50 °C and reacted for 12 h. After rotary evaporation at 50 °C for 1.5 h, 800 ml of deionized water was added and stirred evenly, then extracted three times with n-butanol (500 ml of n-butanol was used each time), vacuum distilled at 60 °C for 1.5 h, and finally separated by a silica gel chromatography column to obtain Intermediate 3.

[0040] S4: Under nitrogen protection, add 500 g of tetrahydrofuran, 50 g of intermediate 3, 60 g of 2-methacryloyloxyethyl phosphorylcholine, and 100 g of 2-acrylamido-2-methylpropanesulfonic acid into a reactor, stir, heat up to 70 °C and react for 30 min, then add 2 g of initiator AIBN, react at 100 °C for 24 h, cool down to room temperature, add 800 g of deionized water, stir evenly, centrifuge, wash with 40 g of absolute ethanol and then wash with 20 g of deionized water, and dry in vacuum at 80 °C for 10 h to obtain the surfactant.

[0041] Preparation of the surfactant in Example 2:

[0042] S1: Under nitrogen protection, add 1 kg of DMSO, 70 g of 3-allyl-2-hydroxybenzaldehyde, and 170 g of epichlorohydrin into a reactor, stir and mix evenly, heat up to 75 °C, add 6.2 g of catalyst TEBAC, continue to heat up to 110 °C, react for 8 h, cool down to 55 °C, then add 30 g of KOH, continue to react for 5 h, carry out vacuum distillation at 70 °C for 40 min, and dry in vacuum at 70 °C for 4 h to obtain intermediate 1.

[0043] S2: Under nitrogen protection, add 280 g of tetrahydrofuran, 175 g of intermediate 1, and 150 g of n-decanol into a reactor, stir and mix evenly, heat up to 90 °C, then add 6 g of sodium hydride, react for 10 h, add 18 ml of 37 wt% hydrochloric acid to neutralize the reaction mixture, then add 300 ml of ether and 300 ml of deionized water for extraction, dry with 80 g of anhydrous sodium sulfate, filter, carry out rotary evaporation at 70 °C for 40 min to obtain the crude product, then recrystallize in 500 ml of ether, and dry in vacuum at 80 °C for 5 h to obtain intermediate 2.

[0044] S3: Under nitrogen protection, add 500 g of tetrahydrofuran, 70 g of intermediate 2, and 135 g of 1,3-propanesultone into a reactor, stir and mix evenly, then add 6.5 g of sodium hydride, heat up to 70 °C and react for 11 h, carry out rotary evaporation at 60 °C for 1 h, then add 800 ml of deionized water and stir evenly, then extract with n-butanol three times (500 ml of n-butanol each time), carry out vacuum distillation at 60 °C for 1.5 h, and finally separate by silica gel chromatography column to obtain intermediate 3. The nuclear magnetic resonance hydrogen spectrum data are as follows:

[0045] 11H NMR (300 MHz, DMSO-d6) δ 9.99 (s, 1H), 7.79 (dd, J = 7.6, 1.5 Hz, 1H), 7.40 - 6.97 (m, 2H), 5.88 (ddt, J = 16.8, 10.0, 6.6 Hz, 1H), 5.49 - 4.75 (m, 2H), 4.50 - 3.79 (m, 3H), 3.86 - 2.99 (m, 8H), 1.84 - 1.45 (m, 4H), 1.45 - 1.08 (m, 15H), 0.89 (td, J = 6.9, 4.0 Hz, 7H).

[0046] S4: Under nitrogen protection, add 500 g of tetrahydrofuran, 75 g of intermediate 3, 90 g of 2-methacryloyloxyethyl phosphorylcholine, and 120 g of 2-acrylamido-2-methylpropanesulfonic acid into the reactor, stir, heat up to 75 °C and react for 25 min, then add 2.2 g of initiator AIBN, react at 110 °C for 20 h, cool to room temperature, add 800 g of deionized water, stir evenly, centrifuge, wash with 40 g of absolute ethanol and then wash with 20 g of deionized water, and dry in vacuum at 90 °C for 8 h to obtain the surfactant.

[0047] Preparation of the surfactant in Example 3:

[0048] S1: Under nitrogen protection, add 1 kg of DMSO, 80 g of 3-allyl-2-hydroxybenzaldehyde, and 200 g of epichlorohydrin into the reactor, stir and mix evenly, heat up to 80 °C, add 6.5 g of catalyst TEBAC, continue to heat up to 120 °C, react for 6 h, cool down to 60 °C, then add 50 g of KOH, continue to react for 4 h, carry out reduced pressure distillation at 70 °C for 1 h, and dry in vacuum at 80 °C for 3 h to obtain intermediate 1.

[0049] S2: Under nitrogen protection, add 300 g of tetrahydrofuran, 200 g of intermediate 1, and 180 g of n-decanol into the reactor, stir and mix evenly, heat up to 100 °C, then add 7 g of sodium hydride, react for 8 h, add 20 ml of 37 wt% hydrochloric acid to neutralize the reaction mixture, then add 300 ml of ether and 300 ml of deionized water for extraction, dry with 80 g of anhydrous sodium sulfate, filter, carry out rotary evaporation at 70 °C for 1 h to obtain the crude product, then recrystallize in 500 ml of ether, and dry in vacuum at 90 °C for 4 h to obtain intermediate 2.

[0050] S3: Under nitrogen protection, add 500 g of tetrahydrofuran, 80 g of intermediate 2, and 150 g of 1,3 - propane sultone into a reactor, stir to mix evenly, then add 7 g of sodium hydride, heat up to 90 °C and react for 10 h. After rotary evaporation at 65 °C for 40 min, add 800 ml of deionized water and stir to mix evenly, then extract three times with n - butanol (500 ml of n - butanol each time), distill under reduced pressure at 65 °C for 1 h, and finally separate with a silica gel chromatography column to obtain intermediate 3.

[0051] S4: Under nitrogen protection, add 500 g of tetrahydrofuran, 100 g of intermediate 3, 120 g of 2 - methacryloyloxyethyl phosphorylcholine, and 140 g of 2 - acrylamido - 2 - methylpropanesulfonic acid into a reactor, stir, heat up to 80 °C and react for 20 min, then add 2.5 g of initiator AIBN, react at 120 °C for 16 h, cool to room temperature, add 800 g of deionized water and stir evenly, centrifuge, wash with 40 g of absolute ethanol and then wash with 20 g of deionized water, and dry in vacuum at 100 °C for 6 h to obtain the surfactant.

[0052] Example 4 Preparation of silicon monoxide nanomaterial:

[0053] S1: Weigh metal silicon powder: 800 g, silicon dioxide powder: 200 g, binder (sodium carboxymethyl cellulose): 5 g, surfactant (prepared in Example 1): 20 g;

[0054] S2: Add 20 g of surfactant into 20 g of absolute ethanol and 100 g of deionized water, stir at 40 °C for 30 min to obtain a surfactant solution;

[0055] S3: Add silicon dioxide powder and metal silicon powder into a mixer and stir to mix. The rotation speed during mixing is 1200 r / min, and the mixing time is 20 min. After mixing evenly, add the binder and the surfactant solution and continue to stir. The rotation speed during mixing is 800 r / min, and the mixing time is 25 min. Press the fully mixed material in a press (the pressure during pressing is 1.5 MPa) into a sheet (50×50×12 mm), and dry in vacuum at 70 °C for 4 h to obtain a raw material sheet;

[0056] S4: Put the dried raw material sheet into a vacuum sintering furnace, carry out a negative - pressure high - temperature reaction. The vacuum degree is 10 Pa, the temperature is 1400 °C, react for 20 h. After the reaction ends, stop heating, fill nitrogen into the vacuum sintering furnace for cooling, cool the furnace temperature to 200 °C, and then naturally cool to room temperature to obtain the silicon monoxide nanomaterial.

[0057] Example 5 Preparation of silicon monoxide nanomaterial:

[0058] S1: Weigh metal silicon powder: 1000 g, silicon dioxide powder: 300 g, binder (sodium carboxymethyl cellulose): 18 g, surfactant (prepared in Example 2): 50 g;

[0059] S2: Add 50 g of surfactant to 50 g of absolute ethanol and 300 g of deionized water, and stir at 40 °C for 30 min to obtain a surfactant solution;

[0060] S3: Add silicon dioxide powder and metal silicon powder to a mixer and stir to mix. The rotation speed during mixing is 1300 r / min, and the mixing time is 15 min. After mixing evenly, add the binder and the surfactant solution and continue to stir. The rotation speed during mixing is 850 r / min, and the mixing time is 20 min. Place the fully mixed material in a press and press it (the pressure during pressing is 1.5 MPa) into a sheet (50×50×12 mm), and dry it in a vacuum at 70 °C for 4 h to obtain a raw material sheet;

[0061] S4: Put the dried raw material sheet into a vacuum sintering furnace, carry out a negative pressure high-temperature reaction. The vacuum degree is 15 Pa, the temperature is 1300 °C, react for 14 h. After the reaction ends, stop heating, fill nitrogen into the vacuum sintering furnace for cooling, cool the furnace temperature to 200 °C, and then naturally cool to room temperature to obtain silicon monoxide nanomaterials.

[0062] Preparation of silicon monoxide nanomaterials in Example 6:

[0063] S1: Weigh metal silicon powder: 1200 g, silicon dioxide powder: 400 g, binder (polyacrylic acid): 30 g, surfactant (prepared in Example 3): 80 g;

[0064] S2: Add 80 g of surfactant to 80 g of absolute ethanol and 400 g of deionized water, and stir at 40 °C for 30 min to obtain a surfactant solution;

[0065] S3: Add silicon dioxide powder and metal silicon powder to a mixer and stir to mix. The rotation speed during mixing is 1500 r / min, and the mixing time is 10 min. After mixing evenly, add the binder and the surfactant solution and continue to stir. The rotation speed during mixing is 900 r / min, and the mixing time is 15 min. Place the fully mixed material in a press and press it (the pressure during pressing is 1.8 MPa) into a sheet (50×50×12 mm), and dry it in a vacuum at 70 °C for 4 h to obtain a raw material sheet;

[0066] S4: Put the dried raw material tablets into a vacuum sintering furnace for a negative pressure high-temperature reaction. The vacuum degree is 20 Pa, the temperature is 1200 °C, and the reaction lasts for 8 h. After the reaction ends, stop heating, fill nitrogen into the vacuum sintering furnace for cooling, cool the furnace temperature to 200 °C, and then naturally cool to room temperature to obtain the silicon monoxide nanomaterial.

[0067] Comparative Example 1

[0068] A silicon monoxide nanomaterial has basically the same raw material composition and process as in Example 5, except that no surfactant is added in the components.

[0069] Comparative Example 2

[0070] A silicon monoxide nanomaterial has basically the same raw material composition and process as in Example 5, except that the surfactant is replaced with an equal weight of Intermediate 3 prepared in Step S3 of Example 2.

[0071] Comparative Example 3

[0072] A silicon monoxide nanomaterial has basically the same raw material composition and process as in Example 5, except that the surfactant is replaced with an equal weight of dodecyldimethylamine.

[0073] Comparative Example 4

[0074] A silicon monoxide nanomaterial has basically the same raw material composition and process as in Example 5, except that the surfactant is replaced with an equal weight of 2-methacryloyloxyethyl phosphorylcholine.

[0075] Comparative Example 5

[0076] A silicon monoxide nanomaterial has basically the same raw material composition and process as in Example 5, except that the surfactant is replaced with 13 g of Intermediate 3 (prepared in Step S3 of Example 2), 16 g of 2-methacryloyloxyethyl phosphorylcholine, and 21 g of 2-acrylamido-2-methylpropanesulfonic acid.

[0077] Comparative Example 6

[0078] A silicon monoxide nanomaterial is prepared by the following raw materials and process:

[0079] S1: Weigh 1000 g of metallic silicon powder, 300 g of silicon dioxide powder, 18 g of binder (sodium carboxymethylcellulose), and 120 g of surfactant (prepared in Example 2);

[0080] S2: Add 120 g of surfactant to 120 g of absolute ethanol and 600 g of deionized water, and stir at 40 °C for 30 min to obtain a surfactant solution;

[0081] S3: Add silicon dioxide powder and silicon metal powder into a mixer and stir them. The rotation speed during mixing is 1300 r / min and the mixing time is 15 min. After mixing evenly, add a binder and a surfactant solution and continue stirring. The rotation speed during mixing is 850 r / min and the mixing time is 20 min. Place the fully mixed material in a press and press it (the pressure during pressing is 1.5 MPa) into a sheet (50×50×12 mm), and dry it in vacuum at 70 °C for 4 h to obtain a raw material sheet.

[0082] S4: Put the dried raw material sheet into a vacuum sintering furnace and carry out a negative pressure high-temperature reaction. The vacuum degree is 15 Pa, the temperature is 1300 °C, and the reaction lasts for 14 h. After the reaction ends, stop heating, fill nitrogen into the vacuum sintering furnace for cooling, cool the furnace temperature to 200 °C, and then naturally cool it to room temperature to obtain silicon monoxide nanomaterials.

[0083] In Examples 4-6 and Comparative Examples 1-7 of this application, the particle size of the silicon metal powder used is 100 mesh, purchased from Henan Jin'ao Metallurgy Co., Ltd.; the particle size of the silicon dioxide powder is: D50 = 130 nm, D98 = 150 nm, purchased from Jinan Zhongbei Fine Chemical Co., Ltd.; the carboxymethyl cellulose sodium is Daicel CMC2200; the polyacrylic acid is LA133, a special water-based binder for lithium-ion batteries.

[0084] The pore size of the silicon monoxide nanomaterials prepared in Examples 4-6 and Comparative Examples 1-6 of this application was tested by the mercury intrusion method, and the test results are shown in Table 1.

[0085] The silicon monoxide nanomaterials prepared in Examples 4-6 and Comparative Examples 1-6 of this application are used as the anode material and mixed with a binder CMC and SRB and a conductive agent (Super-P) according to a mass ratio of 80:5:5:10 to obtain an anode mixed material. Add deionized water (the mixing mass ratio of the anode mixed material to deionized water is 1:1.2) as a dispersant to make a slurry, and then coat it on a 9-μm copper foil with a coater. After vacuum drying at 90 °C for 6 h, roll press it, and control the compaction density at 1.20 g / cm 3 , and then use a punching machine to make a round sheet with a diameter of 13 mm, weigh it and calculate the weight of the active material. Assemble it into a CR2430 button cell in a glove box, use a lithium metal sheet as the auxiliary electrode, a polypropylene microporous membrane as the separator, and 1 mol / L LiPF6 dissolved in EC (ethylene carbonate) and DEC (diethyl carbonate) with a volume ratio of 1:1. The battery is left standing at room temperature for 12 h, and a LAND2001CT battery performance tester is used to conduct charge-discharge and cycle performance tests. The voltage range is 0.01-3 V, and the first 100 cycle tests of the anode material are carried out under the condition of a current density of 100 mA / g. The test results are shown in Chart 1.

[0086] Table 1

[0087]

[0088] As can be seen from Examples 4, 5, and 6 in Table 1, the pore diameters of the silicon monoxide nanomaterials prepared by the present invention are mainly distributed in the range of 5-10 nm. The initial Coulombic efficiency is greater than 87%, the initial discharge specific capacity is greater than 1595 mAh / g, and the reversible specific capacity after 100 cycles is greater than 840 mAh / g, showing excellent initial Coulombic efficiency and good cycling performance.

[0089] Comparative Example 1 is a comparative example without adding a surfactant. As can be seen from the data in Table 1, the initial Coulombic efficiency is 69.3%, and the reversible specific capacity after 100 cycles is 401.4 mAh / g.

[0090] Comparative Example 2 is a comparative example different from Example 5. The difference is that the surfactant is replaced with an equal weight of Intermediate 3 prepared in Step S3 of Example 2. As can be seen from the data in Table 1, the initial Coulombic efficiency is 72.6%, and the reversible specific capacity after 100 cycles is 456.7 mAh / g.

[0091] Comparative Example 3 is a comparative example different from Example 5. The difference is that the surfactant is replaced with an equal weight of dodecyldimethylamine. As can be seen from the data in Table 1, the initial Coulombic efficiency is 73.1%, and the reversible specific capacity after 100 cycles is 480.1 mAh / g.

[0092] Comparative Example 4 is a comparative example different from Example 5. The difference is that the surfactant is replaced with an equal weight of 2-methacryloyloxyethyl phosphorylcholine. As can be seen from the data in Table 1, the initial Coulombic efficiency is 75.9%, and the reversible specific capacity after 100 cycles is 506.9 mAh / g.

[0093] The surfactant added in Comparative Example 5 is 13 g of Intermediate 3 (prepared in Step S3 of Example 2), 16 g of 2-methacryloyloxyethyl phosphorylcholine, and 21 g of 2-acrylamido-2-methylpropanesulfonic acid. As can be seen from the data in Table 1, the initial Coulombic efficiency is 77.8%, and the reversible specific capacity after 100 cycles is 545.2 mAh / g.

[0094] The mass of the surfactant added in Comparative Example 6 is 120 g. As can be seen from the data in Table 1, the initial Coulombic efficiency is 76.4%, and the reversible specific capacity after 100 cycles is 586.5 mAh / g.

[0095] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. However, for those of ordinary skill in the art, within the scope of the technical solution of the present invention, any slight changes, modifications and equivalent variations made by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any changes, modifications and equivalent variations made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A silicon monoxide nanomaterial, characterized in that: Prepared from the following raw materials in parts by weight: Metal silicon powder: 80-120 parts, Silicon dioxide powder: 20-40 parts, Binder: 0.5-3 parts, Surfactant: 2-8 parts; The surfactant is prepared by the following method: S1: Under nitrogen protection, DMSO, 3-allyl-2-hydroxybenzaldehyde and epichlorohydrin are added into a reactor, stirred and mixed, heated to 70-80°C, added with catalyst TEBAC, and continued to heat to 100-120°C, reacted for 6-10h, cooled to 50-60°C, then added with KOH, and continued to react for 4-6h. After post-treatment, intermediate 1 is obtained; S2: Under nitrogen protection, tetrahydrofuran, intermediate 1, and n-decanol are added into a reactor, stirred and mixed, heated to 80-100° C., and then sodium hydride is added, reacted for 8-12 hours, and post-treated to obtain intermediate 2; S3: Under nitrogen protection, tetrahydrofuran, intermediate 2, and 1,3-propane sultone are added into a reactor, stirred and mixed, and then sodium hydride is added, and the temperature is raised to 50-90° C. to react for 10-12 hours, and intermediate 3 is obtained after post-treatment; S4: Under nitrogen protection, tetrahydrofuran, intermediate 3, 2-methacryloyloxyethyl phosphorylcholine and 2-acrylamide-2-methylpropanesulfonic acid are added to the reactor, the temperature is raised to 70-80°C and the reaction is carried out for 20-30 minutes, and then the initiator AIBN is added and the reaction is carried out at 100-120°C for 16-24 hours. The surfactant is obtained by post-treatment.

2. The silicon monoxide nanomaterial according to claim 1, characterized in that: In step S1, the mass ratio of DMSO, 3-allyl-2-hydroxybenzaldehyde, KOH and epichlorohydrin is 100:(6-8):(1-5):(15-20).

3. The silicon monoxide nanomaterial according to claim 1, characterized in that: In step S2, the feed mass ratio of the intermediate 1 and n-decanol is (15-20):(12-18).

4. The silicon monoxide nanomaterial according to claim 1, characterized in that: In step S3, the feed mass ratio of tetrahydrofuran, intermediate 2, and 1,3-propane sultone is 50:(6-8):(12-15).

5. The silicon monoxide nanomaterial according to claim 1, characterized in that: In step S4, the feed mass ratio of tetrahydrofuran, intermediate 3, 2-methacryloyloxyethyl phosphorylcholine, and 2-acrylamide-2-methylpropanesulfonic acid is 50:(5-10):(6-12):(10-14).

6. The silicon monoxide nanomaterial according to claim 1, characterized in that: The binder is one of sodium carboxymethyl cellulose and polyacrylic acid.

7. A method for preparing a silicon monoxide nanomaterial according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Weigh by weight: 80-120 parts of metallic silicon powder, 20-40 parts of silicon dioxide powder, 0.5-3 parts of binder, and 2-8 parts of surfactant; S2: Add the surfactant to anhydrous ethanol and deionized water, and stir at 40°C for 30 min to mix the solution evenly; S3: adding silicon dioxide powder and metallic silicon powder into a mixer and stirring and mixing, adding a binder and a surfactant solution after mixing, continuing to stir, placing the fully mixed material into a press to press into a sheet, and then drying; S4: placing the dried raw material sheet into a vacuum sintering furnace for negative pressure and high temperature reaction. After the reaction is completed, the heating is stopped, and nitrogen is filled into the vacuum sintering furnace for cooling. The furnace temperature is cooled to 200°C, and then naturally cooled to room temperature to obtain silicon monoxide nanomaterials.

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