阅读说明：本技术 一种生物氧化亚硅的制备方法及其产物 (Preparation method of biological silicon monoxide and product thereof ) 是由 金之坚 张学臣 于 2020-02-25 设计创作，主要内容包括：本发明公开了一种生物氧化亚硅的制备方法,包括如下步骤：步骤一：将稻壳进行清洗以去除重金属,经过碳化处理后经脱碳处理得生物二氧化硅粗料；步骤二：将所述生物二氧化硅粗料进行粉碎处理,后放入浓度为30-40％的盐酸当中浸泡后,再使用纯水浸泡若干次,真空干燥得生物二氧化硅；步骤三：采用甲烷和高纯氢气的混合气体作为还原介质,对所述生物二氧化硅进行脱氧处理得生物氧化亚硅。本发明还公开了其产物。本发明解决了现有硅材料从铜箔上剥落现象,防止了由此造成的锂电池内部短路产生的高温发热,避免了在工作状态中电池燃烧现象。生物氧化亚硅内部呈多孔状态,通过吸收大量的锂离子,从而使锂电的克容量比和首次充放电效率有所提升。(The invention discloses a preparation method of biological silicon monoxide, which comprises the following steps: the method comprises the following steps: cleaning rice hulls to remove heavy metals, and performing carbonization treatment and decarburization treatment to obtain a biological silicon dioxide coarse material; step two: crushing the crude biological silicon dioxide, soaking in 30-40% hydrochloric acid, soaking in pure water for several times, and vacuum drying to obtain biological silicon dioxide; step three: and (3) deoxidizing the biological silicon dioxide by using a mixed gas of methane and high-purity hydrogen as a reduction medium to obtain the biological silicon monoxide. The invention also discloses a product thereof. The invention solves the problem that the existing silicon material is peeled off from the copper foil, prevents the high-temperature heating caused by the internal short circuit of the lithium battery, and avoids the battery combustion phenomenon in the working state. The interior of the biological silicon monoxide is in a porous state, and a large amount of lithium ions are absorbed, so that the gram capacity ratio and the first charge-discharge efficiency of the lithium battery are improved.)

1. A method for preparing biological silicon monoxide is characterized by comprising the following steps:

the method comprises the following steps: cleaning rice hulls to remove heavy metals, and performing carbonization treatment and decarburization treatment to obtain a biological silicon dioxide coarse material;

step two: crushing the crude biological silicon dioxide, soaking in 30-40% hydrochloric acid, soaking in pure water for several times, and vacuum drying to obtain biological silicon dioxide;

step three: and deoxidizing the biological silicon dioxide by using a mixed gas of methane and high-purity hydrogen as a reduction medium to obtain the biological silicon monoxide, wherein the temperature of the deoxidation treatment is 1200-1400 ℃.

2. The method for preparing biological silicon monoxide according to claim 1, wherein the carbonization treatment in the first step is performed at a temperature ranging from 250 ℃ to 400 ℃ using a muffle furnace, and the decarburization treatment is performed at a temperature ranging from 400 ℃ to 900 ℃ using a tube furnace.

3. The method of claim 1, wherein the pulverizing step in the second step is to pulverize the bio-silica coarse material to a particle size of 500-2500 mesh.

4. The method of claim 1, wherein the hydrochloric acid concentration in the second step is 36%.

5. The method according to claim 1, wherein the hydrochloric acid immersion time in the second step is 2-6 hours;

and the pure water soaking in the second step is soaking for at least three times, and each time lasts for at least three hours.

6. The method of claim 1, wherein the vacuum drying in step two is performed at 70 ℃ for 12 hours.

7. The method according to claim 1, wherein the ratio of methane in the mixed gas in the third step is 2% to 5%.

8. The method for preparing biological silicon monoxide as claimed in claim 1, wherein in the deoxidation treatment in the third step, the air input is 0.21L-0.89L/min, the temperature is first raised to 1210-1400 ℃ at a heating rate of 10 ℃/min and then is maintained for 30-60 minutes, and then the biological silicon monoxide is obtained by rapid cooling.

9. The method of claim 1, wherein the bio-silicon oxide is SiOx (0< X < 2).

10. A bio-silica according to any one of claims 1 to 9 wherein the bio-silica is produced by the above method.

Technical Field

The invention relates to the field of preparation of silicon oxide, and particularly relates to a preparation method of biological silicon oxide and a product thereof.

Background

In the application field of lithium batteries, the addition of silicon particles in a negative electrode material can greatly improve the capacity ratio, but the silicon particles extracted by the existing inorganic material can generate about 300% expansion when the lithium battery is charged and discharged, so that the silicon electrode material is pulverized and peeled off from the surface of a current collector, an active substance and the current collector lose electric contact, a new solid electrolyte layer SEI is continuously generated, and meanwhile, the poor conductivity of the active substance of the SEI enables the impedance of an electrode to be gradually increased in the charging and discharging processes, so that the performance of the lithium battery is deteriorated, and the charging and discharging cycle of the lithium battery is short.

Therefore, in order to solve the problem in the prior art, the silica derived from minerals is used as an additive, and the expansion of the silica during the charging and discharging of the lithium battery is about half of that of pure silicon, so that the charging and discharging period of the lithium battery can be relatively prolonged, but the peeling phenomenon still exists, and the problem is not completely solved.

Disclosure of Invention

In order to overcome the above-mentioned defects of the prior art, the present invention aims to provide a method for preparing biological silicon oxide and a product thereof.

In order to realize the purpose of the invention, the adopted technical scheme is as follows:

a method for preparing biological silicon monoxide comprises the following steps:

the method comprises the following steps: cleaning rice hulls to remove heavy metals, and performing carbonization treatment and decarburization treatment to obtain a biological silicon dioxide coarse material;

step two: crushing the crude biological silicon dioxide, soaking in 30-40% hydrochloric acid, soaking in pure water for several times, and vacuum drying to obtain biological silicon dioxide;

step three: and deoxidizing the biological silicon dioxide by using a mixed gas of methane and high-purity hydrogen as a reduction medium to obtain the biological silicon monoxide, wherein the temperature of the deoxidation treatment is 1200-1400 ℃.

In a preferred embodiment of the present invention, the carbonization treatment in the first step is performed at a temperature ranging from 250 ℃ to 400 ℃ using a muffle furnace, and the decarburization treatment is performed at a temperature ranging from 400 ℃ to 900 ℃ using a tube furnace.

In a preferred embodiment of the present invention, the pulverizing treatment in the second step is to pulverize the bio-silica coarse material to a particle size of 500 mesh to 2500 mesh.

In a preferred embodiment of the present invention, the hydrochloric acid concentration in the second step is 36%.

In a preferred embodiment of the present invention, the hydrochloric acid soaking time in the second step is 2 to 6 hours.

In a preferred embodiment of the present invention, the soaking in pure water in the second step is at least three times, each time for at least three hours.

In a preferred embodiment of the present invention, the vacuum drying in the second step is drying at 70 ℃ for 12 hours.

In a preferred embodiment of the present invention, the ratio of methane in the mixed gas in the third step is 2% -5%.

In a preferred embodiment of the invention, in the deoxidation treatment in the third step, the air input is 0.21L-0.89L/min, the temperature is firstly increased to 1210-1400 ℃ at the temperature increasing rate of 10 ℃/min, the temperature is kept for 30-60 minutes, and then the biological silicon monoxide is obtained after rapid temperature reduction.

In a preferred embodiment of the invention, the biological silicon oxide is SiOx, (0< X < 2).

Biological silica prepared by the method.

The invention has the beneficial effects that:

the problem that the existing silicon material is peeled off from the copper foil is solved, high-temperature heating caused by internal short circuit of the lithium battery is prevented, and the phenomenon of battery combustion in a working state is effectively avoided. The prepared biological silicon monoxide is in a porous state, and the gram capacity ratio and the first charge-discharge efficiency (coulomb efficiency) of the lithium battery are greatly improved by absorbing a large amount of lithium ions.

Drawings

FIG. 1 is an electron micrograph of the biological silica according to the present invention.

FIG. 2 is an XRD pattern of the bio-silica of the present invention.

Detailed Description