CN103288088B - A kind of preparation method of polysilicon - Google Patents
A kind of preparation method of polysilicon Download PDFInfo
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- CN103288088B CN103288088B CN201210141961.5A CN201210141961A CN103288088B CN 103288088 B CN103288088 B CN 103288088B CN 201210141961 A CN201210141961 A CN 201210141961A CN 103288088 B CN103288088 B CN 103288088B
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The present invention relates to a kind of preparation method of polysilicon, this polysilicon is solar level purity, in the process of this polysilicon of preparation, electric energy is provided in reaction system, thus the temperature reduced needed for reaction, make reaction conditions gentleer, optimize the processing condition preparing polysilicon, and improved the purity of polysilicon by further purification process, the method has industrial prospect.
Description
Technical field
The invention belongs to area of solar cell, particularly relate to field prepared by solar energy polycrystalline silicon.
Background technology
Sun power, as a kind of renewable energy source, has very many advantages, is considered to 21 century most important new forms of energy.The development space of China in new forms of energy is very wide, and solar energy industry all achieves significant progress in research and development, industrialization, market development.Polysilicon is the base mateiral of electronic industry and solar energy industry, and polysilicon market is increased rapidly in recent years.
Polysilicon as the material of solar battery sheet, can require that purity reaches 69 (99.9999%), i.e. the polysilicon of so-called solar-grade polysilicon or 6N rank.The method of producing solar energy level silicon at present both at home and abroad method and the silane decomposition adopting improvement siemens to extract silicon more, purity can up to 11 9, but the method exists the problems such as temperature is high, energy consumption is large, the three wastes are many, the needs of existing crystal silicon solar energy battery development can not be met.
And industrial silicon purification at present is generally realized by metallurgy method, metallurgy method mainly contains following several method: acid wash, air blast, slag practice, directional solidification method etc., it is low that the method has production cost, environmental pollution is little, the features such as safety, but the polysilicon obtained by conventional metallurgical method can only reach 4N level, can't use as solar silicon wafers.Therefore, also need further refining, but make the method for the solar energy polycrystalline silicon obtaining 6N rank more complicated, cost price is high.
Summary of the invention
The invention provides that a kind of preparation technology is simple, production cost is low, environmentally friendly and be easy to the preparation method of the polysilicon of industrialization.
A preparation method for polysilicon, described preparation method comprises the steps: reaction raw materials to insert in reaction vessel, and described reaction raw materials comprises silicofluoride and the metal as reductive agent; Electrode insertion in described reaction vessel, described electrode comprises positive pole and negative pole, applies voltage between described positive pole and negative pole; Heat under shielding gas atmosphere and stir described reaction raw materials; After reaction raw materials to the first temperature described in continuous heating, the insulation scheduled time, cooling obtains reduzate; Described reduzate is used successively pure water, acid elution drying treatment, obtain described polysilicon.
Preferably, the voltage range be applied between described positive pole and negative pole is 2-12V.
Preferably, described just very silicon chip or graphite, described negative pole is silicon chip.
Preferably, the purity grade of described silicofluoride is at least analytical pure, and described silicofluoride is selected from potassium silicofluoride or Sodium Silicofluoride.
Preferably, the purity grade of described metal is at least chemical pure, and described metal is selected from potassium or sodium.
Preferably, the weight ratio of described silicofluoride and metal is 2.8:1 to 4:1.
Preferably, described first temperature range is 140-200 DEG C.
Preferably, the purity grade of described acid is electronic pure, is selected from hydrochloric acid, hydrofluoric acid, at least one in sulfuric acid.
Preferably, described drying treatment is vacuum-drying or lyophilize.
Preferably, described shielding gas is selected from nitrogen or argon gas.
The preparation method of polysilicon provided by the invention, in the process preparing polysilicon, electric energy is provided in reaction system, thus the temperature reduced needed for reaction, make reaction conditions gentleer, optimize the processing condition preparing silicon, and have highly purified polysilicon by further purification process acquisition, the method has industrial prospect.
Accompanying drawing explanation
Below in conjunction with drawings and embodiments, the invention will be further described.
Fig. 1 is the X ray diffracting spectrum of polysilicon in the embodiment of the present invention 1;
Fig. 2 is the X ray diffracting spectrum of silicon obtained in embodiment 6, comparative example 1 and 2.
Embodiment
A preparation method for polysilicon, comprise the steps: reaction raw materials to insert in reaction vessel, reaction raw materials comprises silicofluoride and the metal as reductive agent; Electrode insertion in reaction vessel, electrode comprises positive pole and negative pole, applies voltage between a positive electrode and a negative electrode; Heating also stirring reaction raw material under shielding gas atmosphere; After continuous heating reaction raw materials to the first temperature, the insulation scheduled time, cooling obtains reduzate; Reduzate is used successively pure water, acid elution drying treatment, obtain polysilicon.
Silicofluoride as one of reaction raw materials needs through drying treatment before inserting reaction vessel, mainly remove the water that may exist in silicofluoride, when containing a small amount of water in silicofluoride, can react with metal, thus produce unnecessary by product, the temperature range of dry silicofluoride is 100-140 DEG C, and time of drying, scope was 1-12 hour, and drying process can be complete in vacuum drying oven.The purity grade of silicofluoride is at least analytical pure, to avoid the impurity introducing other in reaction system.Silicofluoride is the silicofluoride of IA race metallic element, and silicofluoride can be selected from solid Sodium Silicofluoride or anhydrous potassium silicofluoride.
As the metal of reductive agent for reducing silicofluoride, metal is IA race metallic element, is selected from sodium Metal 99.5 or potassium metal.Same, the purity grade of metal is at least chemical pure.Preferably, the metallic element in silicofluoride is same with the metallographic phase as reductive agent.When the metallic element in silicofluoride and the metallographic phase as reductive agent while, reduction reaction is carried out more thoroughly and by product is few, is conducive to the purification of polysilicon.In addition, when metal is potassium, react constantly with Sodium Silicofluoride, the temperature opposing metallic that reduction reaction occurs be sodium, low, therefore low to the requirement of conversion unit when being Sodium Silicofluoride of silicofluoride, but sodium Metal 99.5 is compared potassium and is had cost advantage.
The scope of the weight ratio of silicofluoride and metal is 2.8:1 to 4:1.Silicofluoride is excessive a little relative to metal, so that with the silicofluoride that the unreacted in water dissolution reduzate is complete in subsequent purification process, reach the object of purified silicon, and when silicofluoride is too much, in purification process, required water amount is also many, therefore, preferably, the part by weight of the metal of silicofluoride and reductive agent is 3:1.In a specific embodiment, silicofluoride contains solid Sodium Silicofluoride, and metal contains sodium Metal 99.5, and the reaction principle specifically preparing silicon is: 4Na+Na
2siF
6=Si+6NaF.
After silicofluoride and the metal as reductive agent insert reaction vessel in the lump, electrode insertion in reaction vessel, electrode comprises positive pole and negative pole, and the voltage range applied between a positive electrode and a negative electrode is 2-12V.Positive pole can be silicon chip or graphite flake, and negative pole can be silicon chip.Concrete applying voltage is between a positive electrode and a negative electrode different, the temperature that reduction reaction occurs is different, and in an embodiment, reaction raw materials is Sodium Silicofluoride and sodium Metal 99.5, the voltage applied between a positive electrode and a negative electrode is 3.4V, and reduction reaction can occur at 170 DEG C; In another embodiment, the voltage applied between a positive electrode and a negative electrode is 3.7V, and reduction reaction can occur at 160 DEG C.
The preparation method of polysilicon provided by the invention, reaction raw materials addition of volts DS, namely in reaction system, energy is provided, addition of electric work, according to Gibbs free energy law, burst into reversible work to system, open a kind of new reaction path, during energising, activation energy is lower than reaction activity when not being energized, reduce reaction and carry out completely required temperature, reduction reaction is carried out milder, optimize the processing condition preparing polysilicon, the requirement of conversion unit is reduced simultaneously, make the application of this preparation method in industrialization more feasible.
The present invention, by electrode insertion in reaction vessel, reaches the object providing electric energy to reaction system, thus optimizes the condition of reduction reaction generation, and any improvement based on this object of those skilled in the art all belongs within the scope of protection of present invention.
In reduction reaction process, fully contact with the metal as reductive agent to make silicofluoride, reduction reaction is carried out more complete, need to stir reaction raw materials, in a specific embodiment, in reaction vessel, add stirring-head, the specific form of stirring-head is not limit, and can be mechanical stirring head or magnetic agitation head.
Need carry out under shielding gas atmosphere when silicofluoride and the metal generation reduction reaction as reductive agent, to avoid air to impact reaction, and produce unnecessary by product, shielding gas does not react with reducing metal.Shielding gas is selected from the one in nitrogen, argon gas.In a particular embodiment, shielding gas is nitrogen.
Under shielding gas atmosphere, reaction raw materials is heated, after in question response container, air drains, stir and continuous heating reaction raw materials to the first temperature, when reductive agent is sodium Metal 99.5, when reacting with Sodium Silicofluoride, the scope of the first temperature is 140-200 DEG C, after temperature reaches the first temperature, the insulation scheduled time, object makes reduction reaction continue for some time occurs, scheduled time scope is 0.5-4 hour, in a specific embodiment, when reductive agent is sodium Metal 99.5, when reacting with Sodium Silicofluoride, voltage is 3V, remain in 165 DEG C of oil baths, reduction reaction can be carried out completely.Preparation method provided by the invention, owing to providing electric work to reduction reaction system, therefore makes reduction reaction can occur smoothly at a lower temperature, thus obtained required polysilicon, optimize the technique preparing polysilicon.
The weight ratio of the metal of silicofluoride and reductive agent is 2.8:1 to 4:1, silicofluoride is excessive a little, therefore reduzate is not only containing silicon, fluoride salt, also has the reaction raw materials silicofluoride that unreacted is complete simultaneously, therefore, in order to obtain highly purified silicon, need to do purification processes further to reduzate.
The present invention is mainly obtained by optimized fabrication process and wash environment has highly purified polysilicon, avoids the pollution that koniology and reaction vessel etc. bring, and use dissolved in purified water salt mode to carry out purified silicon, silicon is water insoluble when normal temperature.
Reduzate is used pure water, acid elution successively, filters post-drying, obtain that there is highly purified polysilicon.In purification process, the purity grade of acid is electronic pure, is selected from hydrofluoric acid, hydrochloric acid, at least one in sulfuric acid.Concrete selection gist is that under normal temperature, acid can be removed by the impurity of sodium reduction, as iron, calcium, magnesium, aluminium etc., but elemental silicon can not be caused to be oxidized, thus obtain high-purity silicon.Acid can be single acid, and also can be the mixing of several acid, mixing acid has stronger acidity relative to single acid, better to the solvability of impurity.In a specific embodiment, adopt pure water, acid elution reduzate 3-5 time respectively, and suction filtration, finally, silicon purification processes crossed carries out drying treatment.
Because silicon easily surface oxidation occurs at middle high temperature, therefore during drying treatment silicon, temperature is unsuitable too high.Concrete, can by purified silicon vacuum drying treatment at 20 ~ 50 DEG C, time dry, vacuum tightness is at least less than 0.5 pascal, or adopts lyophilize, and drying temperature is less than 25 DEG C, to reduce silicon surface oxidation.
The technology of existing purified silicon, mainly improves the purity of silicon by high melt, temperature generally up to thousands of degree, and is in a vacuum furnace, and purification condition is very harsh.In the preparation process in accordance with the present invention, mainly by improving experimental situation, optimized fabrication process, adopt clean reaction raw materials, washing reagent, avoid the pollution that koniology and reaction vessel etc. bring, so not only obtain highly purified silicon, but also avoid the high melt process of power consumption, processing condition harshness, preparation method's industrial applications prospect of the polysilicon that the present invention is disclosed is more objective.
Specific to preparing in the embodiment of silicon, reaction raw materials Sodium Silicofluoride and sodium Metal 99.5 being weighed, inserting to send out and answering in container, in reaction vessel, add top electrode and stirring-head, electrode comprises positive pole and negative pole, just very silicon chip, negative pole is silicon chip, passing into nitrogen to get rid of air wherein, reacting by heating raw material to sending out to answer in container, starting to start after air drains and stirring, continue reacting by heating raw material subsequently to 160 DEG C, be incubated and carry out reduction reaction in 2 hours, obtain reduzate, cooling.Because reduzate is not only containing silicon, therefore need to carry out purification processes to reduzate, concrete purification step is: adopt pure water reduzate 3 times, vacuum filtration, the product obtained after suction filtration is washed 3 times by the hydrochloric acid of electronic pure rank, the silicon vacuum-drying at 50 DEG C after washing is obtained polysilicon in 12 hours.
Below by embodiment, the present invention is further described.
Embodiment 1
Weigh reaction raw materials Sodium Silicofluoride and sodium Metal 99.5 according to weight ratio 3: 1, reaction raw materials is inserted in three mouthfuls of clean vials, pass into N
2get rid of the air in bottle, electrode and stirring-head is added in bottle, electrode comprises positive pole and negative pole, positive pole and negative pole are all silicon chip, and additional volts DS is between a positive electrode and a negative electrode 3.7V, and reacting by heating raw material to 100 DEG C also starts stirring, continue reacting by heating raw material to the first temperature 160 DEG C subsequently, be incubated 2 hours, stop stirring, be cooled to room temperature.The reduzate of gained is proceeded to the clean beaker that pure water is housed, washing vacuum filtration, by the pure water 3 times of the product after suction filtration, then wash also vacuum filtration further with electronics pure hydrochloric acid, finally vacuum-drying 12 hours at 60 DEG C.
Fig. 1 is the X ray diffracting spectrum of the polysilicon that embodiment 1 obtains.The purity of display silicon is analyzed 99.9999% eventually through ICP-Mass.
Embodiment 2
In example 2, electrode auxiliary voltage is 3.4V, and the first corresponding temperature is 170 DEG C, and all the other preparation methods are with embodiment 1.
Embodiment 3
In embodiment 3, electrode auxiliary voltage is 3V, and the first corresponding temperature is 165 DEG C, and all the other preparation methods are with embodiment 1.
Embodiment 4
In example 4, electrode auxiliary voltage is 2V, and the first corresponding temperature is 200 DEG C, and all the other preparation methods are with embodiment 1.
Embodiment 5
In embodiment 5, electrode auxiliary voltage is 12V, and the first corresponding temperature is 140 DEG C, and all the other preparation methods are with embodiment 1.
Change the auxiliary voltage of electrode in embodiment 2-5, simultaneously corresponding change the first temperature, reduction reaction all can occur, and final obtained silicon has the purity up to 69.
Embodiment 6
In embodiment 6, reaction raw materials Sodium Silicofluoride and sodium Metal 99.5 amount of substance ratio are 0.3, and Sodium Silicofluoride is excessive a little, and all the other prepare the method for polysilicon with embodiment 1.
Comparative example 1
In comparative example 1, the amount of substance ratio of reaction raw materials Sodium Silicofluoride and sodium Metal 99.5 is 0.25, and the amount of silicofluoride and sodium Metal 99.5 is just in time according to stoichiometry.All the other prepare the method for polysilicon with embodiment 1.
Comparative example 2
In comparative example 2, the amount of substance ratio of reaction raw materials Sodium Silicofluoride and sodium Metal 99.5 is slightly less than 0.25, and sodium Metal 99.5 is excessive a little, and all the other prepare the method for polysilicon with embodiment 1.
Fig. 2 is the X ray diffracting spectrum of silicon obtained in embodiment 6, comparative example 1 and 2.R represents the amount of substance ratio of Fluoride for Raw Material water glass and sodium Metal 99.5, and in figure, to represent that R obtains silicon when being greater than 0.25 purer for result, and R is less than 0.25, represents that sodium Metal 99.5 is excessive, and cause reaction subsequent step to be difficult to purify, when R is 0.3, impurity peaks is minimum.
Although done detailed elaboration and citing to technical scheme of the present invention above; for a person skilled in the art; on the basis not departing from essence of the present invention, above-described embodiment to be modified and/or flexible or adopt similar replacement scheme, also in protection scope of the present invention.
Claims (8)
1. a preparation method for polysilicon, described preparation method comprises the steps: reaction raw materials to insert in reaction vessel, and described reaction raw materials comprises silicofluoride and the metal as reductive agent; Electrode insertion in described reaction vessel, described electrode comprises positive pole and negative pole, between described positive pole and negative pole, apply voltage, and the voltage range be applied between described positive pole and negative pole is 2-12V; Heat under shielding gas atmosphere and stir described reaction raw materials; After reaction raw materials to the first temperature described in continuous heating, the insulation scheduled time, cooling obtains reduzate, and described first temperature range is 140-200 DEG C; Described reduzate is used successively pure water, acid elution drying treatment, obtain described polysilicon.
2. preparation method according to claim 1, is characterized in that: described just very silicon chip or graphite, and described negative pole is silicon chip.
3. preparation method according to claim 1, is characterized in that: the purity grade of described silicofluoride is at least analytical pure, and described silicofluoride is selected from potassium silicofluoride or Sodium Silicofluoride.
4. preparation method according to claim 1, is characterized in that: the purity grade of described metal is at least chemical pure, and described metal is selected from potassium or sodium.
5. preparation method according to claim 1, is characterized in that: the weight ratio of described silicofluoride and metal is 2.8:1 to 4:1.
6. preparation method according to claim 1, is characterized in that: the purity grade of described acid is electronic pure, is selected from hydrochloric acid, hydrofluoric acid, at least one in sulfuric acid.
7. preparation method according to claim 1, is characterized in that: described drying treatment is vacuum-drying or lyophilize.
8. preparation method according to claim 1, is characterized in that: described shielding gas is selected from nitrogen or argon gas.
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| CN105206818B (en) * | 2015-10-22 | 2017-12-01 | 中国科学院宁波材料技术与工程研究所 | A kind of preparation method and applications of silicon/metal nanometer composite material |
| CN106744973B (en) * | 2016-11-20 | 2018-12-07 | 安徽大学 | A kind of method that sonochemistry prepares unformed silicon nano material |
| CN106943669B (en) * | 2017-02-21 | 2020-10-09 | 鑑道生命科技有限公司 | Nano-silver particle organic silicon body surface patch electrode and manufacturing method thereof |
| CN110931727A (en) * | 2019-10-25 | 2020-03-27 | 合肥国轩高科动力能源有限公司 | Preparation method of conductive polymer-coated silicon-based negative electrode material |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4446120A (en) * | 1982-01-29 | 1984-05-01 | The United States Of America As Represented By The United States Department Of Energy | Method of preparing silicon from sodium fluosilicate |
| US4597948A (en) * | 1982-12-27 | 1986-07-01 | Sri International | Apparatus for obtaining silicon from fluosilicic acid |
| US4642228A (en) * | 1985-07-24 | 1987-02-10 | Angel Sanjurjo | Fluxing system for reactors for production of silicon |
| CN101492836A (en) * | 2008-01-23 | 2009-07-29 | 中信国安盟固利新能源科技有限公司 | Method for manufacturing solar battery grade polysilicon product |
| CN101724852A (en) * | 2008-10-20 | 2010-06-09 | 比亚迪股份有限公司 | Method for preparing solar grade polycrystalline silicon material |
| CN102267697A (en) * | 2010-06-04 | 2011-12-07 | 刘新林 | Process for producing solar grade polysilicon with sodium circulation method |
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| CN102157731B (en) * | 2011-03-18 | 2015-03-04 | 上海交通大学 | Silicon and carbon compound anode material of lithium ion battery and preparation method of silicon and carbon compound anode material |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4446120A (en) * | 1982-01-29 | 1984-05-01 | The United States Of America As Represented By The United States Department Of Energy | Method of preparing silicon from sodium fluosilicate |
| US4597948A (en) * | 1982-12-27 | 1986-07-01 | Sri International | Apparatus for obtaining silicon from fluosilicic acid |
| US4642228A (en) * | 1985-07-24 | 1987-02-10 | Angel Sanjurjo | Fluxing system for reactors for production of silicon |
| CN101492836A (en) * | 2008-01-23 | 2009-07-29 | 中信国安盟固利新能源科技有限公司 | Method for manufacturing solar battery grade polysilicon product |
| CN101724852A (en) * | 2008-10-20 | 2010-06-09 | 比亚迪股份有限公司 | Method for preparing solar grade polycrystalline silicon material |
| CN102267697A (en) * | 2010-06-04 | 2011-12-07 | 刘新林 | Process for producing solar grade polysilicon with sodium circulation method |
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| CN103296262A (en) | 2013-09-11 |
| CN103288088A (en) | 2013-09-11 |
| CN103296262B (en) | 2015-08-19 |
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