CN114975959B - Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon - Google Patents
Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon Download PDFInfo
- Publication number
- CN114975959B CN114975959B CN202210711949.7A CN202210711949A CN114975959B CN 114975959 B CN114975959 B CN 114975959B CN 202210711949 A CN202210711949 A CN 202210711949A CN 114975959 B CN114975959 B CN 114975959B
- Authority
- CN
- China
- Prior art keywords
- silicon
- carbon composite
- preparing
- photovoltaic industry
- waste silicon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 91
- 239000010703 silicon Substances 0.000 title claims abstract description 91
- 239000002699 waste material Substances 0.000 title claims abstract description 46
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 30
- 239000002131 composite material Substances 0.000 title claims abstract description 27
- 239000010405 anode material Substances 0.000 title claims abstract description 14
- 238000005520 cutting process Methods 0.000 title claims abstract description 10
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 98
- 239000011856 silicon-based particle Substances 0.000 claims abstract description 21
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 claims abstract description 14
- 229930006000 Sucrose Natural products 0.000 claims abstract description 14
- 239000005720 sucrose Substances 0.000 claims abstract description 14
- 238000005406 washing Methods 0.000 claims abstract description 13
- 229920000642 polymer Polymers 0.000 claims abstract description 9
- 239000002243 precursor Substances 0.000 claims abstract description 8
- 239000007788 liquid Substances 0.000 claims abstract description 5
- 238000000926 separation method Methods 0.000 claims abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 239000008367 deionised water Substances 0.000 claims description 22
- 229910021641 deionized water Inorganic materials 0.000 claims description 22
- 238000001035 drying Methods 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- 238000001914 filtration Methods 0.000 claims description 13
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 12
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 11
- 239000002244 precipitate Substances 0.000 claims description 9
- 239000004576 sand Substances 0.000 claims description 9
- 239000011863 silicon-based powder Substances 0.000 claims description 9
- 238000002156 mixing Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- 238000001291 vacuum drying Methods 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 7
- 229910001416 lithium ion Inorganic materials 0.000 claims description 7
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 238000000227 grinding Methods 0.000 claims description 5
- 238000003763 carbonization Methods 0.000 claims description 4
- 235000006408 oxalic acid Nutrition 0.000 claims description 4
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 4
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 4
- 239000000047 product Substances 0.000 claims description 4
- 239000002002 slurry Substances 0.000 claims description 4
- 239000006230 acetylene black Substances 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 235000019441 ethanol Nutrition 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 239000011268 mixed slurry Substances 0.000 claims description 3
- 239000007773 negative electrode material Substances 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims description 3
- 238000010000 carbonizing Methods 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 239000007795 chemical reaction product Substances 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 238000002360 preparation method Methods 0.000 claims description 2
- 238000012216 screening Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 9
- 229910003481 amorphous carbon Inorganic materials 0.000 abstract description 6
- 238000001027 hydrothermal synthesis Methods 0.000 abstract description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 abstract description 4
- 229910052744 lithium Inorganic materials 0.000 abstract description 4
- 238000004064 recycling Methods 0.000 abstract description 4
- 238000009830 intercalation Methods 0.000 abstract description 3
- 230000002687 intercalation Effects 0.000 abstract description 3
- 230000008859 change Effects 0.000 abstract description 2
- 238000000197 pyrolysis Methods 0.000 abstract description 2
- 239000002994 raw material Substances 0.000 abstract description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 abstract 2
- 229910052786 argon Inorganic materials 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 21
- 229910008938 W—Si Inorganic materials 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 7
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 4
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- 239000008103 glucose Substances 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 239000010406 cathode material Substances 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 238000000498 ball milling Methods 0.000 description 2
- 229910021419 crystalline silicon Inorganic materials 0.000 description 2
- 230000001351 cycling effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000005549 size reduction Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000013014 purified material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/134—Electrodes based on metals, Si or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- 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 invention belongs to the technical field of recycling of cut waste silicon, and particularly relates to a method for preparing a silicon/carbon composite anode material by utilizing photovoltaic industry linear cut waste silicon, which comprises the following steps: 1) Reducing micron-sized waste silicon to submicron by mechanical sanding; 2) Pre-oxidizing and chemically purifying the thinned silicon particles to obtain purified silicon particles; 3) And performing hydrothermal reaction on sucrose serving as a carbon source and purified silicon to obtain a precursor of polymer coated silicon particles, performing centrifugal washing to complete solid-liquid separation, and finally performing pyrolysis on the precursor under argon to obtain the silicon/carbon composite material. The method takes low-cost photovoltaic industry wire-electrode cutting waste silicon and sucrose as raw materials to coat a conductive amorphous carbon layer on the surface of the waste silicon. The carbon layer is coated, so that the conductivity of the waste silicon can be improved, the internal stress generated by volume change of the waste silicon in the lithium removal and intercalation process can be effectively relieved, and the electrochemical stability of the composite material is improved. Realizes the recycling of waste silicon, and is suitable for further popularization and application.
Description
Technical Field
The invention belongs to the technical field of recycling of cut waste silicon, and particularly relates to a method for preparing a silicon/carbon composite anode material by utilizing photovoltaic industry linear cut waste silicon.
Background
At present, the commercialized lithium ion battery cathode material is mainly graphite, but the theoretical specific capacity of the graphite is only 370mAh/g, and the development requirement of a high-capacity lithium ion battery cannot be met gradually. The silicon-based negative electrode is the material with the highest theoretical specific capacity (about 4200 mAh/g) at present, and is about 11 times of the theoretical specific capacity of the graphite negative electrode. On the other hand, silicon has a low lithium intercalation potential (about 0.2V, relative to Li/li+), and can output a higher voltage when it is matched with the positive electrode. In addition, the reserve of silicon is rich, is the second element of reserve ranking in the crust, and the silicon is very low in toxicity and environment-friendly. To sum up, silicon is the new generation of high specific capacity lithium ion battery anode material which is the most promising alternative to graphite anode at present. But the problem of exposing the silicon negative electrode is also very obvious. 1. As a semiconductor, the intrinsic conductivity of silicon is low, which directly affects the activity of electrochemical reactions, reducing the capacity output capability of the cell. 2. Silicon cathodes are accompanied by severe volume expansion (300%) during cycling, which can lead to cracking, pulverization, and flaking of the material from the surface of the current collector, resulting in severe capacity fade 3.
In recent years, the development of the photovoltaic industry is rapid, great loss is caused in the actual processing process of online cutting, about 40% of crystalline silicon is lost in the form of micron-sized silicon powder, and the current waste silicon generated in the photovoltaic industry is approximately 20 ten thousand tons/year. There is therefore a need for an efficient way to recycle the photovoltaic industry wire-cut waste silicon.
Disclosure of Invention
In view of the above problems, the present invention provides a method for preparing a silicon/carbon composite anode material by utilizing photovoltaic industry wire-cut waste silicon.
In order to achieve the above purpose, the invention is realized by the following technical scheme:
a method for preparing a silicon/carbon composite anode material by utilizing photovoltaic industry wire-cut waste silicon comprises the following steps:
1) Reducing micron-sized waste silicon to submicron by mechanical sanding;
2) Pre-oxidizing and chemically purifying the thinned silicon particles to obtain purified silicon particles;
3) And performing hydrothermal reaction on sucrose serving as a carbon source and purified silicon to obtain a precursor of polymer coated silicon particles, performing centrifugal washing to complete solid-liquid separation, and finally performing pyrolysis on the precursor under inert gas to obtain the silicon/carbon composite material.
Further, the step 1) is specifically as follows:
the initial waste silicon and deionized water are added into a sand mill to be ground to submicron.
Preferably, the rotational speed of the sand mill in the step 1) is 1500r/min, and the grinding time is 1h.
Further, the step 2) specifically includes:
2.1 Heating and pre-oxidizing the silicon powder after sand grinding in a muffle furnace;
2.2 Adding the pre-oxidized silicon powder into HF solution, (NH) in turn 3 ·H 2 O+H 2 O 2 ) Solution, (HCl+H) 2 O 2 ) Purifying in the solution, filtering and washing the product, and drying to obtain purified silicon particles.
Preferably, the heating temperature in step 2.1) is 850℃and the oxidation time is 1h.
Further, step 2.2) specifically includes:
slowly adding oxidized silicon powder into 10wt% HF, stirring for 1h, filtering and washing;
then add to the mixture of NH 3 ·H 2 O、H 2 O 2 And deionized water in a volume ratio of 1:1:5, treating for 15min at room temperature, filtering and washing;
finally add to the mixture of HCl and H 2 O 2 And deionized water in the volume ratio of 1:1:5, treating at 80 ℃ for 15min, filtering, washing, and drying in a vacuum drying oven at 80 ℃ to obtain purified silicon particles.
Further, the step 3) specifically includes:
3.1 Mixing and stirring the solution 1 and the solution 2, and pouring the mixture into an autoclave for heating reaction to obtain a precursor of the polymer coated silicon particles;
3.2 Cooling the reaction product at room temperature, centrifugally filtering to obtain a precipitate, rinsing the precipitate with deionized water and ethanol for three times, drying, and finally carbonizing the dried precipitate at high temperature in Ar atmosphere to obtain a silicon/carbon composite material;
wherein, the solution 1 is prepared by adding 3.75g of sucrose, 1.75g of oxalic acid and 0.75g of cetyltrimethylammonium bromide into 20ml of deionized water under stirring;
the solution 2 was prepared by adding 0.5g of purified silicon particles, 0.75g of polyvinylpyrrolidone, to 20ml of deionized water with stirring.
Preferably, in the step 3.1), the mixing and stirring time is 60min, the heating temperature is 200 ℃, and the heating time is 12h;
drying the precipitate rinsed in the step 3.2) in a vacuum drying oven at 80 ℃; the carbonization temperature is 700 ℃, and the carbonization time is 6 hours.
In the invention, sucrose is used as a carbon source in the hydrothermal reaction process, oxalic acid with the same molar ratio is added into the sucrose solution, glucose is obtained by hydrolyzing the sucrose in advance, and compared with the glucose obtained by directly adding the glucose into the solution at first, the glucose obtained by hydrolyzing is more active, thereby being beneficial to coating silicon particles by a carbon source polymer.
The PVP can form a layer of film on the surface of irregular waste silicon, so that the active sites on the surface are increased, the combination of cetyl trimethyl ammonium bromide and waste silicon is facilitated, and a polymer grows on the surface of the waste silicon along the direction of cetyl trimethyl ammonium bromide in the hydrothermal reaction process; the effective combination of cetyl trimethylammonium bromide and waste silicon facilitates the coating of silicon particles by the polymer during the hydrothermal reaction.
Conventional purification schemes cannot well remove organic contamination liquids and impurity ions using hydrochloric acid soaking. The invention adopts a one-step pre-oxidation method, removes organic pollution liquid (polyethylene glycol) at 850 ℃, and simultaneously generates an oxide film on the surface of waste silicon. And then removing the oxide film by using hydrofluoric acid, and further reducing the size of the material. Then alkaline cleaning solution (mixed solution of ammonia water and hydrogen peroxide, wherein H 2 O 2 A natural oxide layer can be formed on the silicon surface to make the surface hydrophilic, the cleaning solution can infiltrate the surface, ammonia water can then corrode the natural oxide layer on the surface, so that particles adsorbed on the silicon surface of the waste material can fall into the cleaning solution to be removed, such as Ni 2+ 、Ca 2+ ) With an acidic cleaning solution (a mixed solution of hydrochloric acid and hydrogen peroxide, which can dissolve a plurality of metal ions such as Al which are not complexed by ammonia) 3+ ，Fe 3+ ) And removing metal ions on the silicon surface of the waste material.
The traditional size reduction scheme is that mechanical ball milling can achieve the effect of reducing the size only by long-time mechanical ball milling, and the size of the material can be reduced more quickly by adopting sand milling.
The invention also provides a negative electrode plate, which comprises the prepared silicon/carbon composite negative electrode material, and the preparation method of the negative electrode plate comprises the following steps:
s1: mixing a silicon/carbon composite material, acetylene black and PAA-Li according to a mass ratio of 7:2:1, then adding 70ul deionized water and 30ul absolute ethyl alcohol, preparing into slurry, and stirring for at least 12h;
in the mixing process, the lithiated PAA is used as a binder instead of the traditional CMC, and the lithiated PAA is used as a polymer with soft property, so that the volume expansion of the silicon cathode in the charge and discharge process can be better adapted, and the electrochemical cycling stability of the material can be improved.
S2: coating the uniformly mixed slurry on a Cu foil by using a film drawing device, placing the Cu foil in a vacuum drying oven, drying at 70 ℃ for more than 12 hours, rolling the electrode plate by using a roller after drying, stamping the electrode plate with the diameter of 12mm by using a slicer, and screening out the electrode plate with the complete surface and no crease.
The pole piece is prepared by using a film drawing device to replace the traditional scraper coating, and the thickness of the prepared pole piece is controllable and more uniform. The rolling energy of the roller can enable the material on the pole piece to be more compact, and good contact is beneficial to ion conduction.
The invention further provides a lithium ion battery, which comprises the negative electrode plate.
The beneficial effects are that:
the invention uses low-cost photovoltaic industry line cutting waste silicon (purity is less than 2N) and sucrose as raw materials to coat the conductive amorphous carbon layer on the surface of the waste silicon. The carbon layer is coated, so that the conductivity of the waste silicon can be improved, the internal stress generated by volume change of the waste silicon in the lithium removal and intercalation process can be effectively relieved, and the electrochemical stability of the composite material is improved. The capacity of the composite material still has 1579mAh/g after 150 circles of circulation under the current density of 0.5A/g. The method reduces the cost of the silicon cathode material and provides a recycling way for the silicon waste material of the photovoltaic industry line cutting.
Drawings
FIG. 1 is an SEM image of W-Si;
FIG. 2 is an SEM image of P-Si;
FIG. 3 is an SEM image of P-Si/C;
FIG. 4 is a graph of W-Si particle size versus sanding time;
FIG. 5 is an XRD pattern for W-Si, P-Si/C;
FIG. 6 is a TEM image of P-Si/C;
FIG. 7 is a schematic view showing cycle performance of W-Si and P-Si/C (0.5A/g).
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry wire-cut waste silicon comprises the following steps:
1. the initial scrap silicon was noted as W-Si. 10g W-Si and 500ml deionized water were added to a sand mill for 1h at 1500 r/min.
2. Oxidizing the silicon powder after sand grinding in a muffle furnace at 850 ℃ for 1h. 10g of oxidized silicon powder was then slowly added to 10wt% HF (made up of 25ml 40wt% HF and 75ml deionized water), stirred for 1h, and filtered and washed. Then add to NH 3 ·H 2 O、H 2 O 2 And deionized water (volume ratio is 1:1:5), and filtering and washing. Finally add to the mixture of HCl and H 2 O 2 Treating with deionized water (volume ratio of 1:1:5) at 80deg.C for 15min, filtering, washing, and drying at 80deg.C in vacuum drying oven to obtain the final productThe purified silicon particle product was obtained and designated P-Si.
3. (1) Preparing a solution 1: to 20ml of deionized water was added 3.75g of sucrose, 1.75g of oxalic acid, 0.75g of cetyltrimethylammonium bromide with stirring.
(2) Preparing a solution 2: to 20ml of deionized water, 0.5g of P-Si,0.75g of polyvinylpyrrolidone was added with stirring.
(3) Solution 1 was mixed with solution 2 and vigorously stirred for 60 minutes. The mixed solution was poured into a stainless steel autoclave lined with teflon and kept at 200 ℃ for 12 hours. Cooling at room temperature, centrifuging and filtering to obtain precipitate, and rinsing with deionized water and ethanol three times. The final product was dried in a vacuum oven at 80 ℃ and finally carbonized at 700 ℃ for 6 hours in an Ar atmosphere. The resulting powder was designated as P-Si/C (heating rate 5 ℃ C./min). Wherein Si/C is 1:7.5.
4. (1) And (3) preparing slurry: the active material, acetylene black and PAA-Li are mixed according to the mass percentage of 7:2:1, mixing evenly, adding 70ul deionized water and 30ul absolute ethyl alcohol into the mixture by a liquid-transfering gun, preparing into slurry with moderate viscosity, and stirring for at least 12h.
(2) Preparing a pole piece: coating the uniformly mixed slurry on a Cu foil by using a film drawing device, and drying the Cu foil in a vacuum drying oven at 70 ℃ for more than 12 hours. After drying, the pole piece is rolled by a roller, then is punched into an electrode piece with the diameter of 12mm by a slicer, the complete electrode piece with no crease on the surface is screened out, and finally the quality of the pole piece and the blank Cu foil is weighed.
(3) Half cell assembly in glove box with 2025 cell casing, 1.5mm lithium sheet, 0.8mm spacer, polyethylene (PE) as separator, electrolyte LiPF 6 (1 mol/L)/EC+DEC+EMC, and assembling the button half cell. Standing at room temperature for more than 24 hours, and allowing the electrolyte to infiltrate the diaphragm for electrochemical testing and analysis.
The mass of P-Si is changed to 0.75g, and other experimental conditions of 0.375g are not changed, and the experiment is carried out to obtain P-Si/C1: 5. P-Si/C1: 10.
characterization and testing
As can be seen from fig. 1, the original waste silicon exhibits an irregular morphology, mostly in the form of flakes, layers, and strips, with dimensions varying from a few micrometers to hundreds of nanometers. It can be seen from fig. 2 that the size of the sanded and chemically purified material is significantly reduced and the uniformity of the size is increased.
As shown in FIG. 4, the median diameters (D50) of the particle sizes of the waste silicon after sanding for 60min, 120min, 180min and 240min are respectively 0.445um, 0.381um, 0.348um and 0.286um at the rotating speed of 1500 r/min. As the sanding time increases, the particle size of the waste silicon decreases significantly, presenting a floc. The sanding process conditions at a speed of 1500r/min for 60min were most effective in reducing the size (48.8% reduction in product size).
As can be seen from fig. 3, the waste silicon surface is still flaky after being coated with the sucrose-derived carbon layer, and an uneven amorphous carbon layer appears on the surface.
From FIG. 5, it can be seen that the P-Si after the sanding treatment and chemical purification corresponds one-to-one to the characteristic peaks of silicon on the standard PDF #27-1402, indicating that the main phase of P-Si is still Si without other impurities introduced in the sanding treatment and chemical purification steps. P-Si/C1 after carbon-coated treatment: 5. P-Si/C1: 7.5, P-Si/C1: 10 shows a broad peak around 23 deg. corresponding to amorphous carbon and the characteristic peaks of silicon still correspond one-to-one to standard PDF cards. It is shown that the carbon-in-water method with sucrose as carbon source can introduce amorphous carbon without damaging the silicon phase of the bulk of the material.
As shown in fig. 6, fig. 6a shows that the prepared P-Si/C composite material exhibits a sheet-like structure, and the sheets are combined into an island shape. The lattice fringes at a spacing of 0.31nm in fig. 6C correspond to the (111) lattice planes of Si. Further illustrating the presence of a carbon layer and a major phase crystalline silicon, the feasibility of the sucrose hydrothermal carbon-in-package method is demonstrated.
As shown in FIG. 7, the specific discharge capacity of W-Si was as high as about 3600mAh/g in the first turn, but the capacity suddenly dropped to 300mAh/g after 25 turns, and the electrochemical performance was extremely unstable. The modified three P-Si/C samples have improved cycle performance compared with W-Si samples. P-Si/C1: the specific capacity of 5 is 3000mAh/g after initial discharge, but the capacity decays rapidly after 10 circles, and the specific capacity of the discharge is about 1200mAh/g after 150 circles. The reason is that the silicon occupies larger, and the volume expansion of the silicon in the thin circulation process of the carbon layer cannot be well restrained, so that the first-circle specific capacity is high but the circulation performance is poor. P-SI/C1: the specific capacity of 10 initial discharge is 1824mAh/g, and the capacity after 150 cycles is about 940mAh/g. The reason is that the higher carbon ratio improves the cycle performance, but the lower silicon content does not exert the advantage of high silicon capacity. The specific capacity of the P-Si/C1:7.5 for the first time reaches 2682mAh/g, and after 150 circles of circulation under the current density of 0.5A/g, the capacity still has 1579mAh/g.
Therefore, compared with other two modified samples, the P-Si/C1:7.5 has the advantages that the specific discharge capacity is ensured, and meanwhile, the cycle stability is optimized, so that the method is a preferable scheme. On one hand, the size reduction and the removal of organic dirt and oxide layers on the surface of the waste silicon improve the lithium ion transmission performance. On the other hand, the introduction of the amorphous carbon layer, while losing a part of the first-cycle discharge specific capacity, promotes the cycle stability of the material. Therefore, the invention can indeed improve the electrochemical cycle performance of the photovoltaic industry linear cutting waste silicon as the lithium ion battery cathode material.
While the foregoing is directed to embodiments, embodiments and methods of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (8)
1. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry linear cutting waste silicon is characterized by comprising the following steps of:
1) Reducing micron-sized waste silicon to submicron by mechanical sanding;
2) Pre-oxidizing and chemically purifying the thinned silicon particles to obtain purified silicon particles;
3) Taking sucrose as a carbon source to react with purified silicon in a hydrothermal manner to obtain a precursor of polymer coated silicon particles, performing centrifugal washing to complete solid-liquid separation, and finally pyrolyzing the precursor under inert gas to obtain a silicon/carbon composite material;
the step 2) specifically comprises the following steps:
2.1 Heating and pre-oxidizing the silicon powder after sand grinding in a muffle furnace;
2.2 Adding the pre-oxidized silicon powder into HF solution, (NH) in turn 3 ·H 2 O+H 2 O 2 ) Solution, (HCl+H) 2 O 2 ) Purifying the solution, filtering and washing the product, and drying to obtain purified silicon particles;
the step 3) specifically comprises the following steps:
3.1 Mixing and stirring the solution 1 and the solution 2, and pouring the mixture into an autoclave for heating reaction to obtain a precursor of the polymer coated silicon particles;
3.2 Cooling the reaction product at room temperature, centrifugally filtering to obtain a precipitate, rinsing the precipitate with deionized water and ethanol for three times, drying, and finally carbonizing the dried precipitate at high temperature in Ar atmosphere to obtain a silicon/carbon composite material;
wherein, the solution 1 is prepared by adding 3.75g g sucrose, 1.75g oxalic acid and 0.75g cetyltrimethylammonium bromide into 20ml deionized water under stirring;
the solution 2 was prepared by adding 0.5g of purified silicon particles, 0.75g of polyvinylpyrrolidone, to 20ml of deionized water with stirring.
2. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry wire-cut waste silicon according to claim 1, wherein the step 1) is specifically as follows:
the initial waste silicon and deionized water are added into a sand mill to be ground to submicron.
3. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry line cut waste silicon according to claim 2, wherein the rotating speed of the sand mill in the step 1) is 1500r/min, and the grinding time is 1h.
4. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry line cutting waste silicon according to claim 1, wherein the heating temperature in the step 2.1) is 850 ℃, and the oxidation time is 1h.
5. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry wire-cut waste silicon according to claim 1, wherein the step 2.2) specifically comprises the following steps:
slowly adding the pre-oxidized silicon powder into 10wt% HF, stirring for 1h, and filtering and washing;
then add to the mixture of NH 3 ·H 2 O、H 2 O 2 And deionized water in a volume ratio of 1:1:5, treating for 15min at room temperature, filtering and washing;
finally add to the mixture of HCl and H 2 O 2 And deionized water in the volume ratio of 1:1:5, treating at 80 ℃ for 15min, filtering, washing, and drying in a vacuum drying oven at 80 ℃ to obtain purified silicon particles.
6. The method for preparing the silicon/carbon composite anode material by utilizing the photovoltaic industry line cut waste silicon according to claim 1, wherein the mixing and stirring time in the step 3.1) is 60min, the heating temperature is 200 ℃, and the heating time is 12h;
drying the precipitate rinsed in the step 3.2) in a vacuum drying oven at 80 ℃; the carbonization temperature is 700 ℃, and the carbonization time is 6 hours.
7. A negative electrode sheet, characterized by comprising the silicon/carbon composite negative electrode material prepared by the method for preparing a silicon/carbon composite negative electrode material by utilizing the photovoltaic industry line cutting waste silicon according to one of claims 1-6, wherein the preparation method of the negative electrode sheet comprises the following steps:
s1: mixing a silicon/carbon composite material, acetylene black and PAA-Li according to a mass ratio of 7:2:1, then adding 70ul deionized water and 30ul absolute ethyl alcohol, preparing into slurry, and stirring for no less than 12h;
s2: coating the uniformly mixed slurry on a Cu foil by using a film drawing device, placing the Cu foil in a vacuum drying oven, drying at 70 ℃ for 12 to h, rolling the electrode plate by using a roller after drying, stamping the electrode plate with the diameter of 12 to mm by using a slicing machine, and screening out the electrode plate with the complete surface and no crease.
8. A lithium ion battery comprising the negative electrode sheet of claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210711949.7A CN114975959B (en) | 2022-06-22 | 2022-06-22 | Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210711949.7A CN114975959B (en) | 2022-06-22 | 2022-06-22 | Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114975959A CN114975959A (en) | 2022-08-30 |
| CN114975959B true CN114975959B (en) | 2024-03-01 |
Family
ID=82965341
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210711949.7A Active CN114975959B (en) | 2022-06-22 | 2022-06-22 | Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114975959B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104112850A (en) * | 2014-06-30 | 2014-10-22 | 张力 | Preparation method and application of lithium ion battery negative electrode material based on silicon waste of photovoltaic industry |
| CN104752699A (en) * | 2013-12-31 | 2015-07-01 | 西北大学 | Preparation method of silicon-carbon composite material |
| CN105336922A (en) * | 2014-08-08 | 2016-02-17 | 苏州格瑞动力电源科技有限公司 | Preparation method and application for lithium ion battery negative electrode material based on photovoltaic silicon waste material |
| CN106654220A (en) * | 2017-01-11 | 2017-05-10 | 湘潭大学 | Preparation method of high-capacity carbon-silicon composite negative material |
| CN109904407A (en) * | 2019-01-02 | 2019-06-18 | 昆明理工大学 | A kind of method that Buddha's warrior attendant wire cutting scrap silicon prepares lithium ion battery negative material |
| CN110474032A (en) * | 2019-08-21 | 2019-11-19 | 郑州中科新兴产业技术研究院 | It is a kind of to be given up the silicon-carbon cathode material and preparation method thereof of silicon based on photovoltaic |
| CN110890537A (en) * | 2018-09-11 | 2020-03-17 | 江苏中能硅业科技发展有限公司 | Production method of high-purity nanocrystalline silicon |
| CN111129476A (en) * | 2020-01-17 | 2020-05-08 | 泰州市海创新能源研究院有限公司 | Method for preparing composite lithium ion battery anode material by using silicon wafer waste |
| CN112456498A (en) * | 2020-11-12 | 2021-03-09 | 郑州中科新兴产业技术研究院 | Nano silicon material with hydrophobic coating layer, preparation method and application |
| CN112467067A (en) * | 2020-12-02 | 2021-03-09 | 郑州中科新兴产业技术研究院 | Three-dimensional porous silicon-carbon material prepared by purifying photovoltaic silicon mud and preparation method thereof |
-
2022
- 2022-06-22 CN CN202210711949.7A patent/CN114975959B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104752699A (en) * | 2013-12-31 | 2015-07-01 | 西北大学 | Preparation method of silicon-carbon composite material |
| CN104112850A (en) * | 2014-06-30 | 2014-10-22 | 张力 | Preparation method and application of lithium ion battery negative electrode material based on silicon waste of photovoltaic industry |
| CN105336922A (en) * | 2014-08-08 | 2016-02-17 | 苏州格瑞动力电源科技有限公司 | Preparation method and application for lithium ion battery negative electrode material based on photovoltaic silicon waste material |
| CN106654220A (en) * | 2017-01-11 | 2017-05-10 | 湘潭大学 | Preparation method of high-capacity carbon-silicon composite negative material |
| CN110890537A (en) * | 2018-09-11 | 2020-03-17 | 江苏中能硅业科技发展有限公司 | Production method of high-purity nanocrystalline silicon |
| CN109904407A (en) * | 2019-01-02 | 2019-06-18 | 昆明理工大学 | A kind of method that Buddha's warrior attendant wire cutting scrap silicon prepares lithium ion battery negative material |
| CN110474032A (en) * | 2019-08-21 | 2019-11-19 | 郑州中科新兴产业技术研究院 | It is a kind of to be given up the silicon-carbon cathode material and preparation method thereof of silicon based on photovoltaic |
| CN111129476A (en) * | 2020-01-17 | 2020-05-08 | 泰州市海创新能源研究院有限公司 | Method for preparing composite lithium ion battery anode material by using silicon wafer waste |
| CN112456498A (en) * | 2020-11-12 | 2021-03-09 | 郑州中科新兴产业技术研究院 | Nano silicon material with hydrophobic coating layer, preparation method and application |
| CN112467067A (en) * | 2020-12-02 | 2021-03-09 | 郑州中科新兴产业技术研究院 | Three-dimensional porous silicon-carbon material prepared by purifying photovoltaic silicon mud and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| A Low-Cost Preparation of Si@C Composite Anode from Si Photovoltaic Waste;Shiyun Zhang et al.;《Int. J. Electrochem. Sci.》;6582-6595 * |
| Recycling of micron-sized Si powder waste from diamond wire cutting and its application in Li-ion battery anodes;Kai Wang et al.;《Journal of Cleaner Production》;117997 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114975959A (en) | 2022-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111326723B (en) | Silicon-carbon composite negative electrode material for lithium ion battery and preparation method thereof | |
| CN107507972B (en) | Preparation method of silicon-carbon negative electrode material, silicon-carbon negative electrode material and lithium ion battery | |
| CN112582615B (en) | One-dimensional porous silicon-carbon composite negative electrode material, preparation method and application thereof | |
| CN106848199B (en) | Nano-silicon/porous carbon composite anode material of lithium ion battery and preparation method and application thereof | |
| WO2020140602A1 (en) | Porous silicon material and preparation method therefor, negative battery material, and electrochemical battery | |
| CN109192940B (en) | Titanium dioxide/graphene multi-element modified Mxene composite material and preparation method thereof | |
| CN103708437B (en) | Soft carbon negative material of lithium ion battery, preparation method of soft carbon negative material and lithium ion battery | |
| EP3726628A1 (en) | Lithium ion battery negative electrode material and preparation method therefor | |
| CN104112850B (en) | A kind of preparation method and application of the lithium ion battery negative material based on photovoltaic industry scrap silicon | |
| CN110289408B (en) | Nano silicon and silicon/carbon composite material based on cutting silicon waste material, preparation method and application | |
| KR102237829B1 (en) | Anode material for rechargeable lithium battery, manufacturing method thereof, and rechargeable lithium battery comprising the same | |
| WO2006125358A1 (en) | A composite carbon material of negative electrode in lithium ion battery and its preparation method | |
| CN112366301A (en) | Silicon/silicon oxide/carbon composite negative electrode material for lithium ion battery and preparation method thereof | |
| CN111048764A (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN111477849B (en) | Preparation method of porous Si/SiC/C material and negative electrode material | |
| CN110534710B (en) | Silicon/carbon composite material and preparation method and application thereof | |
| CN112047335A (en) | Combined treatment method for black powder of waste lithium ion battery | |
| CN110649234A (en) | Preparation method of silicon-based negative electrode material with high coulombic efficiency | |
| CN111564630B (en) | Hard carbon material and preparation method thereof | |
| CN110061227B (en) | Lithium battery cathode material with nano silicon remaining in carbon shell and manufacturing method and application thereof | |
| CN111370656A (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN111082035B (en) | Preparation method of sheet-graphene @ silicon @ amorphous carbon-sandwich structure composite material, and product and application thereof | |
| CN114975959B (en) | Method for preparing silicon/carbon composite anode material by utilizing photovoltaic industry wire-electrode cutting waste silicon | |
| JP2015219989A (en) | Negative electrode active material for lithium ion secondary battery and method for producing the same | |
| CN112320802B (en) | Recycling method of silicon-carbon anode material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |