CN104925866B - A kind of bar-shaped WS of high length-diameter ratio2nanocrystalline preparation method - Google Patents

Abstract

The present invention provides a kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method: tungsten hexachloride and thiocarbamide are added in the glycerine mixture with distilled water, obtain mixed solution, by sonic oscillation after addition sodium carboxymethylcellulose after mixed solution sonic oscillation and sodium alginate, obtains solution；Solution is put into oil bath pan completely cuts off air reaction ageing, centrifugation product, successively washing, freeze-drying, i.e. obtain the bar-shaped WS of high length-diameter ratio₂Nanocrystalline.The present invention prepares the bar-shaped WS of high length-diameter ratio₂Nanocrystalline reaction the most once completes, and process equipment is simple and safe and reliable, it is not necessary to the crystallization and thermal treatment in later stage, thus avoids nanometer WS₂Reunion, grain coarsening and the atmosphere reaction that may cause in heat treatment process introduce the defects such as impurity, and finally realize rod-like nano WS₂Orientation growth, and prepared nanocrystalline there is preferable chemical property.

Description

A kind of bar-shaped WS of high length-diameter ratio2Nanocrystalline preparation method

Technical field

The present invention relates to one and prepare the bar-shaped WS of high length-diameter ratio₂Nanocrystalline method, prepares the bar-shaped WS of high length-diameter ratio particularly to a kind of phonochemistry auxiliary oil bath ageing method₂The method of anode material of lithium-ion battery.

Background technology

WS₂Crystal structure and MoS₂Similar, also it is the layer structure of close-packed hexagonal.There is strong chemical bond to be connected between tungsten atom with sulphur atom, and be connected by weak molecular link between interlayer sulphur atom and sulphur atom.Adhesion between layers is still Van der Waals force, with MoS₂Compare, WS₂Interlamellar spacing relatively big, coefficient of friction is lower, between 0.03～0.05.

WS₂Almost the most insoluble in all of medium, including water, oil, alkali and almost all of acid.But free gaseous fluorine, hot sulfuric acid are compared sensitive by it with hydrofluoric acid.WS₂Heat endurance also preferable, its decomposition temperature in an atmosphere is 510 DEG C, 539 DEG C of rapid oxidation, and in vacuum, decomposition temperature is 1150 DEG C.WS₂Radiation resistance be better than graphite, MoS₂, there is good greasy property, be applicable not only to usual lubricating condition, and may be used for high temperature, high pressure, high vacuum, high load capacity, have the working environment that radiation and the medium that is corrosive etc. are harsh.This most fully shows WS₂Can be as stable battery electrode material.

Nanometer WS₂Become the focus of the area researches such as domestic and international chemistry, physics, material science, in addition to being widely used in solid lubrication aspect, have huge application potential at aspects such as catalyst, electrode material, electron probes.Especially WS₂The extensive concern of people is caused as lithium ion battery and sodium ion battery electrode material.Report that vacuum impregnation technology is prepared for order mesoporous WS₂Anode material for lithium-ion batteries [Hao Liu, Dawei Su, Guoxiu Wang, Shi Zhang Qiao.An ordered mesoporous WS₂anode material with superior electrochemical performance for lithium ion batteries[J].J.Mater.Chem.,2012,22:17437-17440.]；Gas-phase presulfiding reaction method is prepared for WS₂Nano particle and WS2 nanotube [A Margolin, F L Deepak, R Popovitz-Biro, et al, Fullerene-like WS₂nanoparticles and nanotubes by the vapor-phase synthesis of WCl_n and H₂S[J].Nanotechnology,200,19:95601-95611.]；Chemical vapour deposition technique is prepared for the WS of sheet self assembly₂Bouquet (CVD) [Arunvinay Prabakaran, Frank Dillon, Jodie Melbourne, et al.WS₂2D nanosheets in 3D nanoflowers[J].Chem.Commun.2014,50:12360-12362.]；Surface active agent assisting alcohol-hydrothermal method is prepared for WS₂Nanometer rods [Guogang Tang, Hua Tang, Changsheng Li, Wenjing Li, Xiaorui Ji.Surfactant-assisted hydrothermal synthesis and characterization of WS₂nanorods[J]. Materials Letters.2011,65:3457-3460.].It addition, use hydro-thermal method to be prepared for WS₂-Graphene is combined sodium-ion battery positive material [Dawei Su, Shixue Dou, Guoxiu Wang.WS₂@graphene nanocomposites as anode materials for Na-ion batteries with enhanced electrochemical performances [J] .Chem.Comm., 2014,50:4192-4195.] and surface active agent assisting alcohol-hydrothermal method be prepared for WS₂-nitrogen-doped graphene laminar composite [Dongyun Chen, Ge Ji, Bo Ding, Yue Ma, Baihua Qu, Weixiang Chen, Jim Yang Lee.In situ nitrogenated grapheme-few-layer WS₂composites for fast and reversible Li⁺storage[J].Nanoscale,2013,5:7890-7896.].But, about preparing single high length-diameter ratio nano bar-shape WS₂Research and relevant report as anode material of lithium-ion battery less.

The preparation WS reported at present₂The method of material mainly have thermal decomposition method [Zhu Yajun, Zhang Xuebin, Ji Yi etc. the preparation method and application [J] of nano tungsten disulfide and molybdenum bisuphide. Chemical Industry in Guangzhou, 2012,3 (40): 4-6.]；Solid-gas sulfuration method [Yan-Hui Li, Yi Min Zhao, Ren Zhi Ma, Yan Qiu Zhu, Niles Fisher, Yi Zheng Jin, Xin Ping Zhang.Novel Route to WOx Nanorods and WS₂Nanotubes from WS₂Inorganic Fullerenes[J].J.Phys.Chem.B.2006,110:18191-18195.]；Evaporation synthetic method [A Margolin, F L Deepak, R Popovitz-Biro, M Bar-Sadan1, Y Feldman, R Tenne.Fullerene-like WS in situ₂nanoparticles and nanotubes by the vapor-phase synthesis of WCl_n and H₂S[J].Nanotechnology.2008,19:95601-95611.]；Spray pyrolysis [Seung Ho Choi, Yun Chan Kang.Sodium ion storage properties of WS₂-decorated three-dimensional reduced graphene oxide microspheres[J].Nanoscale.2015,7:3965-3970]；Mechanical activation method [Zhuangzhi Wu, Dezhi Wang, Xiuqi Zan, Aokui Sun.Synthesis of WS₂Nanosheets by a novel mechanical activation method [J] .Materials Letters, 2010,64:856-858.] [Zheng loses all also to precipitate reducing process, Song Xuchun, Liu Bo, Han Gui, Xu Zhude. the synthesis of nested spherical stratiform enclosed construction nano tungsten disulfide and Exploration of Mechanism [J]. Journal of Inorganic Materials, 2004,3 (19): 653-656.]；Precipitation reducing process, thermal decomposition method and solid phase vulcanizing method all synthesize WS under the conditions of high-temperature atmosphere₂, powder is easily reunited and process conditions are difficult to control to, to the WS needed for preparation₂The utilization rate of raw material is the least；And solid phase method sinters under the conditions of reducing atmosphere or vulcanization reaction occurs, also can cause nanocrystalline reunion, abnormal grain growth, the microstructure of material is difficult to regulate and control.Meanwhile, evaporation and high to equipment requirement and reactant the proportioning of chemical vapour deposition technique are difficult to control in situ, and prepared WS₂Nano material is readily incorporated impurity, and powder is easily reunited.It addition, hydro-thermal method and solvent-thermal method need to prepare nano material under high temperature and high pressure environment and high to equipment requirement, poor stability.

Summary of the invention

It is an object of the invention to provide a kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method.

For reaching above-mentioned purpose, present invention employs techniques below scheme:

Step one: tungsten hexachloride and thiocarbamide are added in the glycerine mixture with distilled water, and stir to tungsten hexachloride and thiocarbamide dissolving, obtain mixed solution, in described mixture, glycerine is (1～4) with the volume ratio of distilled water: (1～4), in described mixed solution, tungsten and the ratio of the amount of the material of sulphur are (1～5): (1～5), W in described mixed solution⁶⁺Concentration be 0.005～0.5mol/L, by mixed solution sonic oscillation 20～60min, obtain solution A；

Step 2: add sodium carboxymethylcellulose and sodium alginate in solution A, and be stirred continuously and make sodium carboxymethylcellulose and sodium alginate fully dissolve, then sonic oscillation 20～60min, obtain solution B；In solution B, the mass ratio of sodium carboxymethylcellulose and sodium alginate is (1～9): (1～9), and in solution B, sodium carboxymethylcellulose and the total mass fraction of sodium alginate are 5～30%；

Step 3: solution B being put into and completely cut off air reaction ageing 1～12h in oil bath pan, oil bath temperature controls, at 50～140 DEG C, to naturally cool to room temperature after reaction；

Step 4: after step 3, centrifugation product, product is grey black precipitation, uses the most successively after deionized water and absolute ethyl alcohol repeated washing product 4～6 times in-10～-60 DEG C of freeze-dryings, i.e. obtains the bar-shaped WS of high length-diameter ratio₂Nanocrystalline.

In described step one and step 2, stirring uses the RCT B S25 type magnetic stirring apparatus that Mettler-Toledo Instrument (Shanghai) Co., Ltd. produces.

In described step one and step 2, sonic oscillation uses the ultrasonic cleaner of 300～1000W, and ultrasonic cleaner uses the model that Kunshan Ultrasonic Instruments Co., Ltd. produces: KQ-1000KDB high power numerical control ultrasonic cleaner.

In described step 3, oil bath pan uses the HH-1 type electric-heated thermostatic water bath of Ke Wei Yongxing, Beijing Instrument Ltd..

In described step 4, cryodesiccated vacuum is 0.0～8.0Pa, and sublimation drying is 3～8h, and freeze drier uses the model that Beijing development in science and technology Co., Ltd of Song Yuan Huaxing manufactures: LGJ-10.

Beneficial effects of the present invention is embodied in:

Owing to the present invention prepares the bar-shaped WS of high length-diameter ratio₂Nanocrystalline reaction the most once completes preparation, and process equipment is simple and safe and reliable, it is not necessary to the crystallization and thermal treatment in later stage, thus avoids nanometer WS₂Reunion, grain coarsening and the atmosphere reaction that may cause in heat treatment process introduce the defects such as impurity.Simultaneously, it is possible to use template (sodium carboxymethylcellulose and sodium alginate) regulation and control obtain high length-diameter ratio club shaped structure, reunion lesser extent, the WS that crystal grain is uniform and pattern is single₂Nanocrystalline.The more important thing is, phonochemistry method require equipment and instrument is the simplest and it is the most nanocrystalline more efficient can to prepare crystallinity rapidly；Meanwhile, ultrasonic cavitation technology is conducive to nucleation, can prepare particle diameter less and be evenly distributed, the nanometer rods of morphology controllable in atmospheric low-temperature liquid phase.Additionally, oil bath thermal-stable, temperature range width and without moisture contamination, can nucleation-growth at short notice, finally realize rod-like nano WS₂Orientation growth, and prepared nanocrystalline present high length-diameter ratio club shaped structure, there is preferable chemical property.

Accompanying drawing explanation

Fig. 1 is the WS prepared by the embodiment of the present invention 4₂Nanocrystalline XRD；

Fig. 2 is the WS prepared by the embodiment of the present invention 4₂Nanocrystalline SEM figure；

Fig. 3 is the WS prepared by the embodiment of the present invention 4₂Nanocrystalline high rate performance figure (voltage range 0～3V) under different current densities.Capacity: charge/discharge capacity, Cycle number: cycle-index.

Detailed description of the invention

With embodiment, the present invention is elaborated below in conjunction with the accompanying drawings.

Embodiment 1:

Step one: by analytically pure tungsten hexachloride (WCl₆) and thiocarbamide (CH₄N₂S) adding in the mixture of glycerine and distilled water, and be stirred continuously, obtain mixed solution, glycerine controls at V with the volume ratio of distilled water_Glycerine∶V _{Distilled water}=1: 1, the ratio of the amount controlling tungsten, sulfur material is n_W∶n_S=2: 3, W in mixed solution⁶⁺Concentration is 0.1mol/L, mixed solution is put into sonic oscillation 30min in the ultrasonic cleaner of 700W so that predecessor fully dissolves, reacts, and obtains solution A；

Step 2: add analytically pure sodium carboxymethylcellulose (CMC) and the mixture of sodium alginate again in solution A, the mass ratio controlling sodium carboxymethylcellulose and sodium alginate is m_CMC∶m_{Sodium alginate}=3: 2, total addition is wt% (wt%_CMC+ wt%_{Sodium alginate})=20%, and be stirred continuously and make sodium carboxymethylcellulose and sodium alginate fully dissolve, it is then placed in sonic oscillation 40min in the ultrasonic cleaner of 700W, obtains solution B；

Step 3: solution B being put into and completely cut off air reaction ageing 8h in the oil bath pan of methyl-silicone oil, oil bath temperature controls, at 80 DEG C, to naturally cool to room temperature after having reacted；

Step 4: centrifugation product, after using deionized water and absolute ethyl alcohol repeated washing 5 times successively in temperature be-40 DEG C, vacuum be 4.0Pa freeze drier in be dried 6h and i.e. obtain the bar-shaped WS that draw ratio is 25 (uniformity of product is the strongest)₂Nanocrystalline.

The WS of gained₂Nanocrystalline is single hexagonal phase WS₂, even size distribution, present high length-diameter ratio nano bar-shape structure, draw ratio is 25；It is 0～3V as anode material of lithium-ion battery at voltage, and current density is respectively 100mA g^-1, 300mA g^-1, 500mA g^-1, 1000mA g^-1, 1500mA g^-1Under the conditions of, reversible storage sodium capacity is respectively 537mAh g^-1, 505mAh g^-1, 420mAh g^-1, 372mAh g^-1, 360mAh g^-1。

Embodiment 2:

Step one: by analytically pure tungsten hexachloride (WCl₆) and thiocarbamide (CH₄N₂S) adding in the mixture of glycerine and distilled water, and be stirred continuously, obtain mixed solution, glycerine controls at V with the volume ratio of distilled water_Glycerine∶V _{Distilled water}=2: 3, the ratio of the amount controlling tungsten, sulfur material is n_W∶n_S=1: 2, W in mixed solution⁶⁺Concentration is 0.01mol/L, mixed solution is put into sonic oscillation 40min in the ultrasonic cleaner of 500W so that predecessor fully dissolves, reacts, and obtains solution A；

Step 2: add analytically pure sodium carboxymethylcellulose (CMC) and the mixture of sodium alginate again in solution A, the mass ratio controlling sodium carboxymethylcellulose and sodium alginate is m_CMC∶m_{Sodium alginate}=1: 4, total addition is wt% (wt%_CMC+ wt%_{Sodium alginate})=10%, and be stirred continuously and make sodium carboxymethylcellulose and sodium alginate fully dissolve, it is then placed in sonic oscillation 40min in the ultrasonic cleaner of 500W, obtains solution B；

Step 3: solution B being put into and completely cut off air reaction ageing 4h in the oil bath pan of methyl-silicone oil, oil bath temperature controls, at 100 DEG C, to naturally cool to room temperature after having reacted；

Step 4: centrifugation product, after using deionized water and absolute ethyl alcohol repeated washing 5 times successively in temperature be-45 DEG C, vacuum be 2.0Pa freeze drier in be dried 5h and i.e. obtain the bar-shaped WS that draw ratio is 20 (uniformity of product is the strongest)₂Nanocrystalline.

The WS of gained₂Nanocrystalline is single hexagonal phase WS₂, even size distribution, present high length-diameter ratio nano bar-shape structure, draw ratio is 20；It is 0～3V as anode material of lithium-ion battery at voltage, and current density is respectively 100mA g^-1, 300mA g^-1, 500mA g^-1, 1000mA g^-1, 1500mA g^-1Under the conditions of, reversible storage sodium capacity is respectively 535mAh g^-1, 503mAh g^-1, 416mAh g^-1, 370mAh g^-1, 358mAh g^-1。

Embodiment 3:

Step one: by analytically pure tungsten hexachloride (WCl₆) and thiocarbamide (CH₄N₂S) adding in the mixture of glycerine and distilled water, and be stirred continuously, obtain mixed solution, glycerine controls at V with the volume ratio of distilled water_Glycerine∶V _{Distilled water}=1: 4, the ratio of the amount controlling tungsten, sulfur material is n_W∶n_S=1: 5, W in mixed solution⁶⁺Concentration is 0.005mol/L, mixed solution is put into sonic oscillation 50min in the ultrasonic cleaner of 400W so that predecessor fully dissolves, reacts, and obtains solution A；

Step 2: add analytically pure sodium carboxymethylcellulose (CMC) and the mixture of sodium alginate again in solution A, the mass ratio controlling sodium carboxymethylcellulose and sodium alginate is m_CMC∶m_{Sodium alginate}=1: 9, total addition is wt% (wt%_CMC+ wt%_{Sodium alginate})=5%, and be stirred continuously and make sodium carboxymethylcellulose and sodium alginate fully dissolve, it is then placed in sonic oscillation 50min in the ultrasonic cleaner of 400W, obtains solution B；

Step 3: solution B being put into and completely cut off air reaction ageing 2h in the oil bath pan of methyl-silicone oil, oil bath temperature controls, at 120 DEG C, to naturally cool to room temperature after having reacted；

Step 4: after centrifugation product, after using deionized water and absolute ethyl alcohol repeated washing 6 times successively in temperature be-50 DEG C, vacuum be 1.0Pa freeze drier in be dried 4h and i.e. obtain the bar-shaped WS that draw ratio is 10 (uniformity of product is the strongest)₂Nanocrystalline.

The WS of gained₂Nanocrystalline is single hexagonal phase WS₂, even size distribution, present high length-diameter ratio nano bar-shape structure, draw ratio is 10；It is 0～3V as anode material of lithium-ion battery at voltage, and current density is respectively 100mA g^-1, 300mA g^-1, 500mA g^-1, 1000mA g^-1, 1500mA g^-1Under the conditions of, reversible storage sodium capacity is respectively 530mAh g^-1, 500mAh g^-1, 412mAh g^-1, 366mAh g^-1, 353mAh g^-1。

Embodiment 4:

Step one: by analytically pure tungsten hexachloride (WCl₆) and thiocarbamide (CH₄N₂S) adding in the mixture of glycerine and distilled water, and be stirred continuously, obtain mixed solution, glycerine controls at V with the volume ratio of distilled water_Glycerine∶V _{Distilled water}=3: 2, the ratio of the amount controlling tungsten, sulfur material is n_W∶n_S=1: 1, W in mixed solution⁶⁺Concentration is 0.5mol/L, mixed solution is put into sonic oscillation 20min in the ultrasonic cleaner of 1000W so that predecessor fully dissolves, reacts, and obtains solution A；

Step 2: add analytically pure sodium carboxymethylcellulose (CMC) and the mixture of sodium alginate again in solution A, the mass ratio controlling sodium carboxymethylcellulose and sodium alginate is m_CMC∶m_{Sodium alginate}=9: 1, total addition is wt% (wt%_CMC+ wt%_{Sodium alginate})=30%, and be stirred continuously and make sodium carboxymethylcellulose and sodium alginate fully dissolve, it is then placed in sonic oscillation 20min in the ultrasonic cleaner of 1000W, obtains solution B；

Step 3: solution B being put into and completely cut off air reaction ageing 12h in the oil bath pan of methyl-silicone oil, oil bath temperature controls, at 50 DEG C, to naturally cool to room temperature after having reacted；

Step 4: centrifugation product, after using deionized water and absolute ethyl alcohol repeated washing 4 times successively in temperature be-30 DEG C, vacuum be 6.0Pa freeze drier in be dried 8h and i.e. obtain the bar-shaped WS that draw ratio is 40 (uniformity of product is the strongest)₂Nanocrystalline.

WS prepared by embodiment 4 as seen from Figure 1₂Nanocrystalline crystallinity is preferable, and purity is high, has certain orientation, is single hexagonal phase WS₂。

WS prepared by embodiment 4 as seen from Figure 2₂Nanocrystalline even structure, even size distribution, without substantially reuniting, present high length-diameter ratio nano bar-shape structure, the diameter of rod is about 50～100nm, and length is about 1.0～2.0 μm, and draw ratio is 40.

The WS prepared by embodiment 4 can be drawn by Fig. 3₂Nanocrystalline is 0～3V at voltage, and current density is respectively 100mA g^-1, 300mA g^-1, 500mA g^-1, 1000mA g^-1, 1500mA g^-1Under the conditions of, reversible storage sodium capacity is respectively 541mAh g^-1, 507mAh g^-1, 425mAh g^-1, 375mAh g^-1, 363mAh g^-1, there is the high rate during charging-discharging of excellence.

The present invention prepares the WS of gained₂Nanocrystalline is single hexagonal phase WS₂, even size distribution, present high length-diameter ratio nano bar-shape structure, a diameter of 0.05～0.2 μm of rod, a length of 1.0～2.0 μm, draw ratio is 10～40；Gained WS₂Nanocrystalline is 0～3V as anode material of lithium-ion battery at voltage, and current density is respectively 100mA g^-1, 300mA g^-1, 500mA g^-1, 1000mA g^-1, 1500mA g^-1Under the conditions of, reversible storage sodium capacity is respectively 530～545mAh g^-1, 500～515mAh g^-1, 410～425mAh g^-1, 365～380mAh g^-1, 350～365mAh g^-1。

In a word, the present invention proposes a kind of simple, and economical, the technology of preparing of efficient anode material of lithium-ion battery, this technical regulation prepares the bar-shaped WS of single high length-diameter ratio₂Nanocrystalline, draw ratio is critically important to the chemical property of lithium ion and anode material of lithium-ion battery, can be effectively improved its specific surface area and high rate performance.Phonochemistry method is combined with oil bath ageing method and prepares the bar-shaped WS of high length-diameter ratio by the present invention₂Nanocrystalline, simple green, the most controlled and can be by controlling precursor aqueous solution proportioning, the regulation and control pattern of product such as template (sodium carboxymethylcellulose and sodium alginate) addition and technique etc. and component under the conditions of atmospheric low-temperature, and than hydro-thermal method and solvent-thermal method efficiently more quickly and security is good, nucleation rate is very fast, and ultrasonic vibration promotes component homogeneous reaction and nucleation.The bar-shaped WS of high length-diameter ratio that the phonochemistry auxiliary oil bath aging method of the present invention is made₂Nanocrystalline purity is high, and good dispersion, size uniform, pattern is homogeneous and has high high rate performance.

Claims (5)

1. the bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method, it is characterised in that: comprise the following steps:

Step one: tungsten hexachloride and thiocarbamide are added in the glycerine mixture with distilled water, and stirs to chlordene Tungsten and thiocarbamide dissolve, and obtain mixed solution, and in described mixture, glycerine is (1～4) with the volume ratio of distilled water: (1～4), in described mixed solution, tungsten and the ratio of the amount of the material of sulphur are (1～5): (1～5), described mixing W in solution⁶⁺Concentration be 0.005～0.5mol/L, by mixed solution sonic oscillation 20～60min, obtain solution A；

Step 2: add sodium carboxymethylcellulose and sodium alginate in solution A, and be stirred continuously and make carboxylic first Base sodium cellulosate and sodium alginate fully dissolve, and then sonic oscillation 20～60min, obtain solution B；Solution B The mass ratio of middle sodium carboxymethylcellulose and sodium alginate is (1～9): (1～9), and in solution B, carboxymethyl is fine Dimension element sodium and the total mass fraction of sodium alginate are 5～30%；

Step 3: solution B being put into and completely cut off air reaction ageing 1～12h in oil bath pan, oil bath temperature controls 50～140 DEG C, after reaction, naturally cool to room temperature；

Step 4: after step 3, centrifugation product, use deionized water and absolute ethyl alcohol the most successively In-10～-60 DEG C of freeze-dryings after washed product, i.e. obtain the bar-shaped WS of high length-diameter ratio₂Nanocrystalline.

A kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method, its feature Being: in described step one and step 2, stirring uses magnetic stirring apparatus.

A kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method, its feature Being: in described step one and step 2, sonic oscillation uses the ultrasonic cleaner of 300～1000W.

A kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method, its feature Being: in described step 3, oil bath pan uses electric-heated thermostatic water bath.

A kind of bar-shaped WS of high length-diameter ratio₂Nanocrystalline preparation method, its feature Being: in described step 4, cryodesiccated vacuum is 0.0～8.0Pa, and sublimation drying is 3～8h.