CN114497497A - Pre-lithiated silica composite material, and preparation method and application thereof - Google Patents
Pre-lithiated silica composite material, and preparation method and application thereof Download PDFInfo
- Publication number
- CN114497497A CN114497497A CN202210085959.4A CN202210085959A CN114497497A CN 114497497 A CN114497497 A CN 114497497A CN 202210085959 A CN202210085959 A CN 202210085959A CN 114497497 A CN114497497 A CN 114497497A
- Authority
- CN
- China
- Prior art keywords
- lithiation
- composite material
- lithiated
- powder
- carbon
- 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.)
- Granted
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 180
- 239000000377 silicon dioxide Substances 0.000 title claims abstract description 85
- 239000002131 composite material Substances 0.000 title claims abstract description 47
- 238000002360 preparation method Methods 0.000 title claims abstract description 21
- 238000006138 lithiation reaction Methods 0.000 claims abstract description 113
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 claims abstract description 106
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 91
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 91
- 150000003839 salts Chemical class 0.000 claims abstract description 62
- 239000011248 coating agent Substances 0.000 claims abstract description 54
- 238000000576 coating method Methods 0.000 claims abstract description 54
- 229910052751 metal Inorganic materials 0.000 claims abstract description 45
- 239000002184 metal Substances 0.000 claims abstract description 45
- 239000003153 chemical reaction reagent Substances 0.000 claims abstract description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 27
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 19
- 239000010703 silicon Substances 0.000 claims abstract description 19
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 10
- 239000000843 powder Substances 0.000 claims description 72
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 54
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 48
- 238000000034 method Methods 0.000 claims description 44
- 239000011780 sodium chloride Substances 0.000 claims description 27
- 230000001681 protective effect Effects 0.000 claims description 25
- 238000002156 mixing Methods 0.000 claims description 23
- 239000000203 mixture Substances 0.000 claims description 23
- 229910052760 oxygen Inorganic materials 0.000 claims description 22
- 239000001301 oxygen Substances 0.000 claims description 22
- 229910001626 barium chloride Inorganic materials 0.000 claims description 20
- 238000010438 heat treatment Methods 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 239000010410 layer Substances 0.000 claims description 13
- 238000002844 melting Methods 0.000 claims description 13
- 230000008018 melting Effects 0.000 claims description 13
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 claims description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 9
- 239000011247 coating layer Substances 0.000 claims description 9
- 229910001416 lithium ion Inorganic materials 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- PAZHGORSDKKUPI-UHFFFAOYSA-N lithium metasilicate Chemical compound [Li+].[Li+].[O-][Si]([O-])=O PAZHGORSDKKUPI-UHFFFAOYSA-N 0.000 claims description 7
- 229910052912 lithium silicate Inorganic materials 0.000 claims description 7
- 239000007773 negative electrode material Substances 0.000 claims description 7
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims description 6
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 claims description 6
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 claims description 6
- 239000001110 calcium chloride Substances 0.000 claims description 5
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 229910013698 LiNH2 Inorganic materials 0.000 claims description 4
- 239000012448 Lithium borohydride Substances 0.000 claims description 4
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 3
- 229910004835 Na2B4O7 Inorganic materials 0.000 claims description 3
- 229910003074 TiCl4 Inorganic materials 0.000 claims description 3
- JHXKRIRFYBPWGE-UHFFFAOYSA-K bismuth chloride Chemical compound Cl[Bi](Cl)Cl JHXKRIRFYBPWGE-UHFFFAOYSA-K 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- HWSZZLVAJGOAAY-UHFFFAOYSA-L lead(II) chloride Chemical compound Cl[Pb]Cl HWSZZLVAJGOAAY-UHFFFAOYSA-L 0.000 claims description 3
- AFRJJFRNGGLMDW-UHFFFAOYSA-N lithium amide Chemical compound [Li+].[NH2-] AFRJJFRNGGLMDW-UHFFFAOYSA-N 0.000 claims description 3
- 229910001629 magnesium chloride Inorganic materials 0.000 claims description 3
- UBZYKBZMAMTNKW-UHFFFAOYSA-J titanium tetrabromide Chemical compound Br[Ti](Br)(Br)Br UBZYKBZMAMTNKW-UHFFFAOYSA-J 0.000 claims description 3
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 claims description 3
- 239000011592 zinc chloride Substances 0.000 claims description 3
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims description 3
- 229920001296 polysiloxane Polymers 0.000 claims 2
- 239000013078 crystal Substances 0.000 abstract description 22
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 18
- 239000002245 particle Substances 0.000 abstract description 18
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 abstract description 12
- 229910052744 lithium Inorganic materials 0.000 abstract description 12
- 239000002002 slurry Substances 0.000 abstract description 8
- 230000008859 change Effects 0.000 abstract description 6
- 238000001556 precipitation Methods 0.000 abstract description 4
- 238000000605 extraction Methods 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 22
- 230000008569 process Effects 0.000 description 19
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 18
- 230000000694 effects Effects 0.000 description 13
- 230000002829 reductive effect Effects 0.000 description 13
- 239000007789 gas Substances 0.000 description 10
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 9
- 229910052786 argon Inorganic materials 0.000 description 9
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M potassium chloride Inorganic materials [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 8
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 6
- 230000004927 fusion Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 230000036632 reaction speed Effects 0.000 description 5
- 229910001556 Li2Si2O5 Inorganic materials 0.000 description 4
- 229910007562 Li2SiO3 Inorganic materials 0.000 description 4
- 229910020489 SiO3 Inorganic materials 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 239000010416 ion conductor Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- 229910018557 Si O Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000000748 compression moulding Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229910052909 inorganic silicate Inorganic materials 0.000 description 2
- 230000002427 irreversible effect Effects 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- YQCIWBXEVYWRCW-UHFFFAOYSA-N methane;sulfane Chemical compound C.S YQCIWBXEVYWRCW-UHFFFAOYSA-N 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000012216 screening Methods 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000009210 therapy by ultrasound Methods 0.000 description 2
- IRPVABHDSJVBNZ-RTHVDDQRSA-N 5-[1-(cyclopropylmethyl)-5-[(1R,5S)-3-(oxetan-3-yl)-3-azabicyclo[3.1.0]hexan-6-yl]pyrazol-3-yl]-3-(trifluoromethyl)pyridin-2-amine Chemical compound C1=C(C(F)(F)F)C(N)=NC=C1C1=NN(CC2CC2)C(C2[C@@H]3CN(C[C@@H]32)C2COC2)=C1 IRPVABHDSJVBNZ-RTHVDDQRSA-N 0.000 description 1
- 239000006245 Carbon black Super-P Substances 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 239000012982 microporous membrane Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 230000002335 preservative effect Effects 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Images
Classifications
-
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- 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
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
In order to solve the technical problem that the cycle performance of a battery is poor due to large absolute volume change in the lithium extraction process caused by the growth of silicon crystal grains after the pre-lithiation treatment of the silicon monoxide in the prior art, the embodiment of the invention provides a pre-lithiation silica composite material and a preparation method and application thereof, wherein in the preparation method, the silicon monoxide is firstly uniformly mixed with a metal salt before the pre-lithiation reaction and then is uniformly mixed with a pre-lithiation reagent for the pre-lithiation reaction; according to the embodiment of the invention, the metal salt is added to wrap all or part of the surfaces of the pre-lithiation reagent particles and the silicon oxide particles, so that the problem of rapid precipitation and growth of silicon crystal particles due to nonuniform pre-lithiation is solved, and the excellent cycle performance is further ensured; the carbon coating effectively solves the problem of gas generation of the aqueous slurry in application, and greatly improves the water resistance.
Description
Technical Field
The invention relates to a pre-lithiated silica composite material, a preparation method and application thereof.
Background
The first lithium intercalation of silica results in irreversible formation of lithium silicate and lithium oxide, which leads to a first inefficiency of silica. When the lithium ion battery is matched with the conventional positive electrode system to manufacture a full battery, the limited lithium ions of the positive electrode cannot be effectively removed after being charged and inserted into the silicon monoxide for the first time, so that the high-capacity characteristic of the silicon substrate is difficult to exert.
In order to improve the first efficiency of the silicon oxide, various materials of lithium pre-supplement technology are developed in the industry, and irreversible capacity loss in the charging and discharging process is reduced by supplementing part of lithium in the silicon-based materials in advance. The pre-lithiation scheme of pre-doping a portion of lithium by directly thermally doping or redox reactions on a silicon oxygen material has received much attention because it does not change the processing of the material in the back-end cell fabrication process.
However, the slurry has high alkalinity in water system due to the existence of residual lithium on the surface after the prelithiation, and the O component of Si-O in the silicon monoxide is more converted into Li in the prelithiation process2O、Li2SiO3、Li2Si2O5The components are equal, residual Si in Si-O is easy to aggregate and even grow up, and the growth of silicon crystal grains causes large absolute volume change in the lithium desorption and insertion process on one hand, is not beneficial to the stability of a pole piece structure and further causes poor cycle performance; on the other hand, the generation of Si microcrystals is easy to react to generate H in an alkaline aqueous solution system2Poor water resistance is not favorable for the stability of the slurry and affects the processability such as uniform coating, which in turn leads to the problem of unsatisfactory final battery performance.
Disclosure of Invention
In order to solve the technical problem that the cycle performance of a battery is deteriorated due to large absolute volume change in the lithium extraction and insertion process caused by the growth of silicon crystal grains after the pre-lithiation treatment of the silicon monoxide in the prior art, the embodiment of the invention provides a pre-lithiation silicon-oxygen composite material, and a preparation method and application thereof.
The embodiment of the invention is realized by the following technical scheme:
in a first aspect, embodiments of the present invention provide a method for preparing a pre-lithiated silica-oxygen composite material, in which a pre-lithiation reaction is performed by uniformly mixing a pre-lithiation reagent with a silicon monoxide before the pre-lithiation reaction.
Further, the preparation method comprises the following steps:
uniformly mixing the silicon monoxide powder with metal salt to obtain a first mixture;
uniformly mixing the first mixture with a pre-lithiation reagent, and carrying out pre-lithiation reaction under a protective atmosphere to obtain pre-lithiated silica-oxygen powder;
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain a pre-lithiated silica composite material;
wherein the metal salt does not react with the silicon monoxide and the prelithiation reagent at the temperature of below 1000 ℃, and the melting temperature of the metal salt is 400-750 ℃.
Further, under a protective atmosphere, carbon coating is carried out on the pre-lithiation powder and a gas-phase organic carbon source to obtain the pre-lithiation silica-oxygen composite material, and the method comprises the following steps:
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiated silica powder;
and removing the metal salt in the carbon-coated pre-lithiated silica powder to obtain the pre-lithiated silica composite material.
Further, uniformly mixing the first mixture with a pre-lithiation reagent, and carrying out pre-lithiation reaction under a protective atmosphere to obtain pre-lithiated silica powder; the method comprises the following steps:
uniformly mixing the first mixture with a pre-lithiation reagent, uniformly heating to the temperature of 600-750 ℃, and carrying out a pre-lithiation reaction; wherein, the time of the prelithiation reaction is 2-10 h;
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiated silica powder; the method comprises the following steps:
after the pre-lithiation reaction, continuously and uniformly heating to the temperature of 700-850 ℃ in a protective atmosphere, introducing a gas-phase organic carbon source for carbon coating, and cooling to obtain carbon-coated pre-lithiated silica powder;
removing metal salt in the carbon-coated pre-lithiated silica powder to obtain a pre-lithiated silica composite material; the method comprises the following steps:
and washing the carbon-coated pre-lithiated silica powder with water to remove metal salts to obtain the pre-lithiated silica composite material.
Further, the oxygen content in the protective atmosphere is less than or equal to 5 ppm.
Further, the mass ratio of the silicon monoxide powder to the metal salt is 100: 8-25; or the mass ratio of the silicon monoxide powder to the metal salt is 100: 10-20;
the mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 50-85; or the mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 60-82.5.
Further, the metal salt comprises LiCl and BiCl3、TiCl4、PbCl2、ZnCl2、MgCl2、LiBr、NaBr、KBr、TiBr4、PbBr2And Na2B4O7Any one or more of;
or the metal salt comprises any one of the following combinations expressed in mass percent:
80％BaCl2+20％NaCl；
50％BaCl2+50％NaCl；
45％NaCl+55％KCl；
30％KCl+20％NaCl+50％BaCl2；
21％NaCl+31％BaCl2+48％CaCl2。
further, the carbon coating temperature is 700-; the carbon coating amount in the carbon-coated pre-lithiated silica powder is 2.5 to 5.5 percent; the oxygen content in the protective atmosphere is less than or equal to 5 ppm.
Further, the prelithiation reagent includes a compound capable of decomposing elemental Li; or the prelithiation reagent comprises LiH, LiNH2、LiBH4And Li3One or more of N.
In a second aspect, embodiments of the present invention provide a pre-lithiated silica composite material, comprising:
a silicon sub-oxide layer;
the carbon coating layer is coated outside the silicon monoxide layer; and a lithium metasilicate layer between the silicon monoxide layer and the carbon coating layer.
In a third aspect, the embodiment of the invention provides a pre-lithiated silica-oxygen composite material prepared by the preparation method or an application of the pre-lithiated silica-oxygen composite material in preparation of a silica negative electrode material of a lithium ion battery.
Compared with the prior art, the embodiment of the invention has the following advantages and beneficial effects:
according to the pre-lithiation silica composite material and the preparation method and application of the pre-lithiation silica composite material, all or part of the surfaces of the pre-lithiation reagent particles and the surfaces of the silicon oxide particles are wrapped by adding the metal salt, so that the pre-lithiation reaction speed is reduced, meanwhile, the heat effect in the pre-lithiation process can be effectively reduced by taking the molten metal salt as a heat absorption medium, the rapid proceeding of the pre-lithiation reaction is effectively slowed down under the combined action of the two aspects, the occurrence of local violent pre-lithiation reaction is effectively prevented, the uniform and stable pre-lithiation process is effectively ensured, the problem of rapid precipitation and growth of silicon crystal particles due to non-uniform pre-lithiation is solved, and the excellent cycle performance is ensured on the basis of improving the first effect.
After the carbon coating is performed with the pre-lithiation, due to the uniformity of the gas phase coating, the carbon coating layer effectively prevents the water from contacting the pre-lithiated silica body, so that the problem of gas generation of the water-based slurry in the application and processing process is caused, the water resistance is greatly improved, the carbon coating has excellent conductive capability, and the integral conductivity of the pre-lithiated silica material is improved.
Drawings
In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort.
FIG. 1 is an X-ray diffraction chart of example 1.
FIG. 2 is an X-ray diffraction chart of comparative example 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be construed as limiting the scope of the invention.
Examples
In order to solve the technical problem that the cycle performance of a battery is deteriorated due to large absolute volume change in the lithium extraction and insertion process caused by the growth of silicon crystal grains after the pre-lithiation treatment of the silicon monoxide in the prior art, the embodiment of the invention provides a pre-lithiation silicon-oxygen composite material, and a preparation method and application thereof.
In the daily development process, the inventor finds that in order to obtain a relatively stable pre-lithiated silicon-oxygen composite material, the main reaction temperature of the silicon monoxide and the pre-lithiation reagent is between 550 and 650 ℃, and a large amount of heat is released in the process, so that how to control the pre-lithiation reaction in the temperature range is moderate, and therefore, the pre-lithiated silicon-oxygen negative electrode material with high performance is realized.
Based on the above, the embodiment of the invention provides a preparation method of a pre-lithiated silica composite material, in the preparation method, before the pre-lithiation reaction, the silicon monoxide is uniformly mixed with a metal salt and then uniformly mixed with a pre-lithiation reagent to carry out the pre-lithiation reaction.
Therefore, the embodiment of the invention realizes the complete or partial wrapping of the surfaces of the pre-lithiation reagent particles and the silicon monoxide particles by adding the metal salt, reduces the pre-lithiation reaction speed, simultaneously effectively reduces the heat effect in the pre-lithiation process by taking the molten metal salt as a heat-absorbing medium, effectively slows down the rapid proceeding of the pre-lithiation reaction under the combined action of the two aspects, effectively prevents the occurrence of local violent pre-lithiation reaction, effectively ensures the uniform and stable pre-lithiation process, solves the problem of rapid precipitation and growth of silicon crystal particles due to non-uniform pre-lithiation, and further ensures excellent cycle performance on the basis of improving the first effect.
Further, an embodiment of the present invention provides a method for preparing a pre-lithiated silica composite material, including:
uniformly mixing the silicon monoxide powder with metal salt to obtain a first mixture;
uniformly mixing the first mixture with a pre-lithiation reagent, and carrying out pre-lithiation reaction under a protective atmosphere to obtain pre-lithiated silica powder;
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain a pre-lithiated silica composite material;
wherein the metal salt does not react with the silicon monoxide and the prelithiation reagent at the temperature of below 1000 ℃, and the melting temperature of the metal salt is 400-750 ℃.
According to the embodiment of the invention, the metal salt with the melting temperature of 400-750 ℃ is added to completely or partially wrap the surfaces of the pre-lithiation reagent particles and the silicon oxide particles, so that the pre-lithiation reaction speed is reduced, meanwhile, the molten metal salt is used as a heat absorption medium to effectively reduce the heat effect in the pre-lithiation process, the two aspects of combined action effectively slow down the rapid advance of the pre-lithiation reaction, the occurrence of local violent pre-lithiation reaction is effectively prevented, the uniform and stable pre-lithiation process is effectively ensured, the problem of nonuniform and rapid precipitation and growth of silicon crystal particles due to pre-lithiation is solved, and the excellent cycle performance is ensured on the basis of improving the first effect.
In addition, the following problems also exist in the prior art: in the prior art, the aqueous slurry is unstable after the pre-lithiation of the silicon monoxide, is easy to generate gas and has poor water resistance; the prelithiated lithium silicate contains inert Li2Si2O5Instead of predominantly or wholly being Li with ionic conductivity2SiO3And/or Li4SiO4The improvement of the dynamic performance is not facilitated; the first efficiency improvement range after the prelithiation is limited, and the process is complex.
After the carbon coating of the technical scheme is implemented for pre-lithiation, due to the uniformity of gas phase coating, the carbon coating layer effectively prevents the problem of gas generation of aqueous slurry in the application and processing process caused by the contact of water to the pre-lithiated silica body, so that the water resistance is greatly improved, the carbon coating has excellent conductive capability, and the integral conductivity of the pre-lithiated silica material is improved.
The addition of the metal salt and the pre-lithiation in the technical scheme are carried out after carbon coating, and the pre-lithiation can be carried out to a higher degree on the basis of ensuring the controllable silicon grain size and the water-resistant effect of the water-based slurry, so that the pre-lithiation silicon oxide is regulated and controlled to form Li with a high ion conductor2SiO3And Li4SiO4Rather than inert Li2SiO5(ii) a On the other hand, the first efficiency is further improved. The generation of the high-ion conductor lithium silicate improves the diffusion speed of lithium ions in the pre-lithiated silica phase, and the dynamic performance is effectively improved by combining with the conductor carbon coating layer on the surface(ii) a The preparation of the silicon-oxygen cathode material with higher first efficiency further improves the first efficiency of the full battery, thereby obtaining higher energy density.
Further, under a protective atmosphere, carbon coating is carried out on the pre-lithiation powder and a gas-phase organic carbon source to obtain the pre-lithiation silica-oxygen composite material, and the method comprises the following steps:
under the protective atmosphere, carrying out carbon coating on the pre-lithiation silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiation silica powder;
and removing the metal salt in the carbon-coated pre-lithiated silica powder to obtain the pre-lithiated silica composite material.
Further, uniformly mixing the first mixture with a pre-lithiation reagent, and carrying out pre-lithiation reaction under a protective atmosphere to obtain pre-lithiated silica powder; the method comprises the following steps:
uniformly mixing the first mixture with a pre-lithiation reagent, uniformly heating to the temperature of 600-750 ℃, and carrying out a pre-lithiation reaction; wherein, the time of the prelithiation reaction is 2-10 h;
the temperature of the prelithiation reaction is 600-750 ℃, specifically 600 ℃, 625 ℃, 650 ℃, 675 ℃, 700 ℃, 725 ℃ or 750 ℃, preferably 650-700 ℃.
The time of the prelithiation reaction is 2-10 h; specifically, the reaction time may be 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, preferably 4 to 8 h.
The prelithiation time is too short (less than 2h), so that the prelithiation is insufficient and the first efficiency is difficult to improve; the too long time (more than 10h) easily causes grain growth, and simultaneously causes a longer production period, which is not beneficial to reducing the cost.
Under the protective atmosphere, carrying out carbon coating on the pre-lithiation silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiation silica powder; the method comprises the following steps:
after the pre-lithiation reaction, continuously and uniformly heating to the temperature of 700-850 ℃ in a protective atmosphere, introducing a gas-phase organic carbon source for carbon coating, and cooling to obtain carbon-coated pre-lithiated silica powder;
the temperature of the carbon coating is 700-850 ℃, and specifically can be 700 ℃, 725 ℃, 750 ℃, 775 ℃, 800 ℃, 825 ℃ or 850 ℃, and preferably 700-750 ℃.
The coating temperature is too low, the cracking of the organic carbon source is insufficient, the benefit rate is low, and meanwhile, the generated carbon has poor conductivity due to too low temperature; the coating temperature is too high, causing the growth of crystal grains.
Removing metal salt in the carbon-coated pre-lithiated silica powder to obtain a pre-lithiated silica composite material; the method comprises the following steps:
and washing the carbon-coated pre-lithiated silica powder with water to remove metal salts to obtain the pre-lithiated silica composite material.
Further, the oxygen content in the protective atmosphere is less than or equal to 5 ppm.
Further, the mass ratio of the silicon monoxide powder to the metal salt is 100: 8-25; or the mass ratio of the silicon monoxide powder to the metal salt is 100: 10-20;
the mass ratio of the silicon monoxide powder to the metal salt is 100: 8-25; specifically, the ratio may be 100:8, 100:10, 100:12.5, 100:15, 100:17.5, 100:20, 100:22.5 and 100: 25. Preferably 100: 10-20.
If the metal salt is added too little, the violent lithiation reaction cannot be effectively buffered; if too much lithium is added, the lithiation reaction is too slow, and the efficiency is low.
The mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 50-85; or the mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 60-82.5.
The mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 50-85; specifically, it may be 100: 50. 100, and (2) a step of: 55. 100, and (2) a step of: 50-60, 100: 65. 100, and (2) a step of: 70. 100, and (2) a step of: 75. 100, and (2) a step of: 80 and 100: 85 parts by weight; preferably 100: 60-82.5.
The adding amount of the pre-lithiation reagent is too small, the pre-lithiation degree is low, and the first efficiency cannot be effectively improved; the addition amount is too much, the controllability of the prelithiation is weak, and crystal grains are easy to grow.
Further, the metal salt comprises LiCl and BiCl3、TiCl4、PbCl2、ZnCl2、MgCl2、LiBr、NaBr、KBr、TiBr4、PbBr2And Na2B4O7Any one or more of;
or the metal salt comprises any one of the following combinations expressed in mass percent:
80％BaCl2+20％NaCl；
50％BaCl2+50％NaCl；
45％NaCl+55％KCl；
30％KCl+20％NaCl+50％BaCl2；
21％NaCl+31％BaCl2+48％CaCl2。
furthermore, the carbon coating amount in the carbon-coated pre-lithiated silica powder is 2.5 to 5.5 percent.
The carbon coating amount is 2.5% -5.5%, and specifically can be 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0% or 5.5%;
the carbon coating amount is too low, the coating is insufficient, and the direct contact between water and the pre-lithiated silica cannot be effectively prevented; the carbon coating amount is too high, and the inactive content is high to cause capacity reduction.
Further, the prelithiation reagent includes a compound capable of decomposing elemental Li; optionally, the prelithiation reagent comprises LiH, LiNH2、LiBH4And Li3One or more of N.
In a second aspect, embodiments of the present invention provide a pre-lithiated silica composite material, comprising:
a silicon sub-oxide layer;
the carbon coating layer is coated outside the silicon monoxide layer; and a lithium metasilicate layer between the silicon monoxide layer and the carbon coating layer.
In a third aspect, the embodiment of the invention provides a pre-lithiated silica-oxygen composite material prepared by the preparation method or an application of the pre-lithiated silica-oxygen composite material in preparation of a silica negative electrode material of a lithium ion battery.
Example 1
A preparation method of a pre-lithiated silica composite material comprises the following steps: the method comprises the following steps:
preparing SiO powder: adding the micrometer silicon and the nanometer silicon dioxide raw materials into a fusion machine according to the mass ratio of 1:1, fully and uniformly mixing, adding the mixture into a vacuum reaction furnace after compression molding by a molding press, heating the mixture to 1300 ℃ under the negative pressure of 5Pa to gasify the mixture and deposit the gasified mixture on an adsorption plate, taking out the deposit after full cooling, and crushing the deposit into SiO powder with the D50 of 4.6um by a double-roller mill-jet mill.
Pre-lithiation: uniformly mixing SiO and molten salt LiCl in a mass ratio of 100:15 by a fusion machine, adding LiH accounting for 66% of SiO in a molar ratio, further uniformly mixing, adding into a rotary furnace under the protection of argon, sealing, continuously introducing argon, starting and heating to 680 ℃ at a speed of 2 ℃/min after the oxygen content in the furnace is less than 5ppm, preserving heat for 4 hours, and carrying out pre-lithiation reaction at a rotary speed of 0.5 r/min.
Coating: and after the pre-lithiation reaction time is over, continuously heating to 720 ℃ at a speed of 3 ℃/min, introducing acetylene for carbon coating, adjusting the flow of the acetylene to be 1.5L/min, carrying out coating treatment for 3 hours, closing the acetylene after the coating is over, stopping heating, and simultaneously continuously introducing argon to cool to room temperature to obtain the carbon-coated pre-lithiated silica powder.
Washing with water: and taking out the powder cooled to room temperature, stirring and mixing the powder with deionized water according to the ratio of 1:3, and centrifugally washing to remove LiCl in the powder. And then drying and screening to obtain the pre-lithiation powder.
The sample was sampled and XRD tested, and only Li was observed from XRD of FIG. 12SiO3The crystal form peak of (a) appears, and no LiCl crystal peak appears, indicating that the molten salt formed after the metal salt is molten is completely removed. At the same time, no Si crystal peak was detected, indicating that the growth of silicon crystal grains can be avoided by using the pre-lithiated silica prepared in example 1. While Li2SiO3As an ion conductor, the lithium ion battery is beneficial to the rapid transmission of lithium ions and the dynamic performance is improved.
The carbon-sulfur content analyzer was used to test the coating amount of acetylene pyrolytic carbon to be 4.8%.
Example 2
The LiCl content was adjusted to 10% of SiO, and the other conditions were the same as in example 1.
Example 3
The LiCl content was adjusted to 20% of SiO, and the other conditions were the same as in example 1.
Example 4
Replacement of LiCl with BaCl2Mixture with NaCl, and BaCl2The mass ratio of NaCl to NaCl was 8:2, and the other conditions were the same as in example 1.
Example 5
Replacement of LiCl with BaCl2Mixture with NaCl, and BaCl2The mass ratio of NaCl to NaCl was 5:5, and the other conditions were the same as in example 1.
Example 6
LiCl was replaced with a mixture of KCl and NaCl in a KCl to NaCl mass ratio of 5.5:4.5, and the other conditions were the same as in example 1.
Example 7
Replacement of LiCl with KCl, NaCl and BaCl2And KCl, NaCl and BaCl2The mass ratio was 3:2:5, and the other conditions were the same as in example 1.
Example 8
Replacing LiCl with NaCl and CaCl2With BaCl2And NaCl, CaCl2With BaCl2The mass ratio was 2:5:3, and the other conditions were the same as in example 1.
Example 9
The prelithiation heat treatment temperature was adjusted to 620 ℃ under the same conditions as in example 1.
Example 10
The prelithiation heat treatment time was adjusted to 8 hours, and the other conditions were the same as in example 1.
Example 11
The carbon coating temperature was adjusted to 800 ℃ and the other conditions were the same as in example 1.
Example 12
LiH was added in an amount of 10% based on SiO, and the other conditions were the same as in example 1.
Example 13
LiH was added in an amount of 15% based on SiO under the same conditions as in example 1.
Example 14
The flow rate of acetylene was adjusted to 1.0L/min, and the other conditions were the same as in example 1.
Example 15
Mixing SiO, LiCl and LiNH2The mass ratio of the three is 100:43:34.5 under the protection of argon, and then fully and uniformly mixed by a fusion machine, and the other conditions are the same as those of the example 1.
Example 16
Mixing SiO, LiCl and LiBH4The three materials are fully and uniformly mixed by a fusion machine under the protection of argon according to the mass ratio of 100:41:33, and other conditions are the same as those of the embodiment 1.
Comparative example 1
The conditions were otherwise the same as in example 1, without LiCl. The resulting prelithiated silica composite material is shown with reference to fig. 2. It can be seen from the XRD pattern that there is not only Li2SiO3The crystal form peak of (a) appears, and also has a remarkable crystal form peak of Si, which indicates that the pre-lithiated silica composite material prepared by the comparative example 1 cannot effectively avoid the growth of Si grains.
Comparative example 2
Replacement of LiCl by BaCl with a melting point of 960 deg.C2The other conditions were the same as in example 1.
Comparative example 3
LiH was added in an amount of 7% based on SiO, and the other conditions were the same as in example 1.
Comparative example 4
The carbon coating temperature was increased to 900 ℃ from 720 ℃ in example 1, and the other conditions were the same as in example 1.
Comparative example 5
The preparation method of the carbon-coated prelithiation powder comprises the following steps:
preparing SiO powder: adding the micrometer silicon and the nanometer silicon dioxide raw materials into a fusion machine according to the mass ratio of 1:1, fully and uniformly mixing, adding the mixture into a vacuum reaction furnace after compression molding by a molding press, heating the mixture to 1300 ℃ under the negative pressure of 5Pa to gasify the mixture and deposit the gasified mixture on an adsorption plate, taking out the deposit after full cooling, and crushing the deposit into SiO powder with the D50 of 4.6um by a double-roller mill-jet mill.
Carbon coating: heating SiO powder to 720 ℃ at the speed of 3 ℃/min, introducing acetylene for carbon coating, adjusting the flow of acetylene to be 1.5L/min, carrying out coating treatment for 3 hours, closing acetylene after the coating treatment is finished, stopping heating, and simultaneously continuously introducing argon to cool to room temperature to obtain the carbon-coated silica powder SiO/C.
Pre-lithiation: fully and uniformly mixing SiO/C, LiCl and LiH by a fusion machine under the protection of argon according to the mass ratio of 100:15:12, adding into a rotary furnace under the protection of argon, continuously introducing argon after sealing, starting the rotary furnace to heat to 680 ℃ at the speed of 2 ℃/min after the oxygen content in the rotary furnace is less than 5ppm, and preserving the heat for 4 hours to carry out pre-lithiation reaction at the rotary speed of 0.5 r/min.
Washing with water: and taking out the powder cooled to room temperature, stirring and mixing the powder with deionized water according to the ratio of 1:3, and centrifugally washing to remove LiCl in the powder. And then drying and screening to obtain the carbon-coated pre-lithiation powder.
Comparative example 6
LiCl was not added and washing with water was omitted, and the other conditions were the same as in comparative example 5.
Electrochemical performance test
The electrochemical performance test is carried out by adopting the following method: the materials prepared in the examples 1 to 4 and the comparative examples 1 to 2 are taken as negative electrode materials, mixed with a binder CMC + SRB and a conductive agent (Super-P) according to a mass ratio of 80:5:5:10, added with a proper amount of deionized water to be taken as a dispersing agent to be prepared into slurry, then coated on a copper foil with the thickness of 10 microns by a coating machine, and dried for 6 hours in vacuum (-0.1MPa) at the temperature of 90 ℃. Compacting with roller at a density of 1.30g/cm3Then, a wafer having a diameter of 14mm was prepared by a tablet press, dried at 90 ℃ under vacuum (-0.1MPa) for 5 hours, weighed and the weight of the active material was calculated. Assembling a CR2430 button cell in a glove box, taking a metal lithium sheet as a counter electrode, taking a polypropylene microporous membrane as a diaphragm, and 1mol/L LiPF6(lithium hexafluorophosphate) was dissolved in EC (ethylene carbonate) and DEC (diethyl carbonate) at a volume ratio of 1:1, and an electrolyte solution of 5.0% FEC (fluoroethylene carbonate) was added. The battery is stood for 12 hours at room temperature, then a constant current charge-discharge test is carried out on a blue test system, the battery is charged to 0.005V at 0.05C, and then the battery is discharged to 1.5V at 0.1C to carry out the test of the first reversible specific capacity and the first efficiency. In order to further examine the stability of the material structure, the battery charge and discharge test after the first charge and discharge test is adjusted to be as follows: charging to 0.005V at 0.3C, discharging to 1.5V at 0.5C, repeating the charging and discharging cycle for 300 weeks, and maintaining the discharge specific capacity of the last week compared with the discharge specific capacity of the first week, i.e. the capacity of 300 weeksAnd (4) rate. In addition, to examine the material dynamic performance, the process steps of 0.1C discharge to 1.5V were all unchanged, the charge was 0.05C, 0.3C, 0.5C charge to 0.005V, respectively, and the charge capacity of 0.05C over the charge capacity ratio of 0.3C and the charge capacity of 0.05C over the charge capacity ratio of 0.5C were recorded, respectively.
The silicon crystal grains are calculated by substituting the half-peak width of the Si (111) crystal face into the Sherrer equation according to the X-ray diffraction spectrum.
The pH test was: mixing the prepared negative electrode material with water according to the mass ratio of 1:9, and carrying out pH test on the suspension after carrying out ultrasonic treatment for 5 min.
And (3) gas production observation: mixing the prepared negative electrode material with water according to the mass ratio of 1:9, carrying out ultrasonic treatment for 5min, sealing and standing for 120 hours by using a preservative film, and observing.
The results are shown in tables 1 and 2.
TABLE 1
The difference between examples 1-3 and comparative example 1 is mainly that different amounts of molten salt LiCl are added, the molten salt LiCl is not added in comparative example 1, the pre-lithiation reagent particles and the surfaces of the silicon oxide particles cannot be wrapped due to the lack of low-temperature molten salt (melting point 605 ℃), so that the pre-lithiation reaction speed cannot be inhibited, the molten salt heat-absorbing medium cannot absorb heat released in the violent pre-lithiation process, and finally silicon crystal particles rapidly precipitate and grow, so that the cycle performance is remarkably deteriorated, the cycle retention rate of 300 weeks is only 67.4%, which is greatly lower than that of examples 1-3 by more than 90%. At the same time, due to thermal runaway, Li with conductive ions is formed2SiO3Partial conversion to inert Li2Si2O5The dynamic performance is reduced, the capacity retention rate of 0.3C/0.05C is 95.1 percent, and the capacity retention rate of 0.5C/0.05C is 92.4 percent, which are all lower than that of the examples 1-3 by more than 97 percent. The difference between examples 1, 4-8 and comparative example 2 is mainly that molten salts having different melting points were added, and in comparative example 2, molten salt BaCl having a melting point of 960 ℃ was added2Because the melting point of the molten salt is too high, similar to the comparative example 1, the molten salt cannot be melted in the main temperature section of the pre-lithiation reaction, so that the surfaces of the pre-lithiation reagent particles and the silicon oxide particles cannot be wrapped, the pre-lithiation reaction speed cannot be inhibited, the heat released in the violent pre-lithiation process cannot be absorbed due to the lack of the molten salt heat-absorbing medium, and finally, the silicon crystal particles are rapidly precipitated and grown, so that the cycle performance and the dynamic performance are poor. The melting points of the molten salts used in examples 1, 4-8 were 605 deg.C, 635 deg.C, 640 deg.C, 660 deg.C, 560 deg.C, 435 deg.C, respectively, and the molten salts were all liquefied at 680 deg.C within the main pre-lithiation reaction temperature range, thereby achieving a good buffering effect on pre-lithiation, and further avoiding grain growth and inactive lithium polysilicate Li2Si2O5Thereby ensuring good cycling and dynamic performance. In addition, the gas generation is observed in the examples 1 to 8 and the comparative examples 1 to 2 after being soaked in water for 120 hours, which is mainly because the carbon coating is carried out after the pre-lithiation, and the complete coating on the surface avoids the corrosion of water to the pre-lithiated silica body, thereby inhibiting the gas generation.
TABLE 2
Referring to table 2, it can be seen from example 9 that the adjustment of the prelithiation reaction to 680 ℃ to 620 ℃ in example 1, which is above the melting point of molten salt LiCl, still achieves a good effect, but due to the reduced temperature, the prelithiation degree is reduced compared to example 1, and the conversion of the silicon oxide to lithium silicate is reduced, so the first effect is reduced compared to example 1, but the capacity is higher. Example 10 adjusted prelithiation time from 4h to 8h in example 1, example 11 final coating temperature increased to 800 ℃, example 12 prelithiation decreased to 10%, and example 13 prelithiationThe chemical change increased to 15%, which corresponds to similar effect of example 9, i.e. the prelithiation degree increased or decreased with increasing temperature, increasing time, decreasing prelithiation reagent amount, increasing prelithiation reagent amount, which is shown by the corresponding increase or decrease in the first capacity and first effect, and the kinetic performance, grain and gas production effect are maintained at a better level due to the existence of molten salt and coating after prelithiation. Example 14 complete coating of pre-lithiated silica was achieved despite the reduced acetylene level, with a carbon coating level of 3.1% as measured by a carbon-sulfur analyzer, thus maintaining good overall performance. Examples 15-16 exchange different prelithiation reagents, although LiNH in example 152(melting point 373 ℃ C.), LiBH in example 164(melting point 268 ℃), but the main reaction temperature for lithiation with the silicon oxide is still 550-650 ℃, so that under the action of molten salt LiCl, better comprehensive performance is still realized. Comparative example 3 compared to examples 1, 13, 14, the degree of prelithiation was low, resulting in a low first efficiency of only 86.5%, and the lower degree of prelithiation reduced Li2SiO3The kinetic performance is also reduced. Compared with examples 1 and 11, the coating temperature is increased to 900 ℃, and the excessive temperature leads to the remarkable increase of crystal grains, so that the circulation capacity retention rate is remarkably reduced, and meanwhile, the carbon content is 6.7% through a carbon content test, and the further reduction of the capacity is also caused by the excessive inactive content. Compared with the embodiment 1 in the comparative examples 5 and 6, because the pre-lithiation mode is adopted, lithium ions are inserted into the coated complete silica in the lithiation process, and the carbon layer cracks are generated due to volume expansion, so that the interior of the pre-lithiation silica is directly contacted with water, and the pH value is obviously higher than that of the embodiment, and meanwhile, the gas generation and the water resistance effect are poor. In addition, comparing comparative example 5 with comparative example 6, in comparative example 5, since the molten salt was added, the mild progress of prelithiation could be still controlled, while in comparative example 6, the molten salt was not added, the controllability of the reaction caused the growth of crystal grains, and the cycle performance was further deteriorated.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. The preparation method of the pre-lithiated silica composite material is characterized in that before the pre-lithiation reaction, the silicon oxide is uniformly mixed with a metal salt and then uniformly mixed with a pre-lithiation reagent to carry out the pre-lithiation reaction.
2. The method of preparing a prelithiated silicone oxygen composite material of claim 1, comprising:
uniformly mixing the silicon monoxide powder with metal salt to obtain a first mixture;
uniformly mixing the first mixture with a pre-lithiation reagent, and carrying out pre-lithiation reaction under a protective atmosphere to obtain pre-lithiated silica powder;
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain a pre-lithiated silica composite material;
wherein the metal salt does not react with the silicon monoxide and the prelithiation reagent at the temperature of below 1000 ℃, and the melting temperature of the metal salt is 400-750 ℃.
3. The method of preparing the pre-lithiated silica composite material of claim 2, wherein the pre-lithiated powder is carbon-coated with a gaseous organic carbon source in a protective atmosphere to obtain the pre-lithiated silica composite material, comprising:
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiated silica powder;
and removing metal salt in the carbon-coated pre-lithiated silica powder to obtain the pre-lithiated silica composite material.
4. The method for preparing the pre-lithiated silica-oxygen composite material according to claim 3, wherein the first mixture is uniformly mixed with a pre-lithiation reagent, and pre-lithiation reaction is carried out under a protective atmosphere to obtain pre-lithiated silica-oxygen powder; the method comprises the following steps:
uniformly mixing the first mixture with a pre-lithiation reagent, uniformly heating to the temperature of 600-750 ℃, and carrying out a pre-lithiation reaction; wherein, the time of the prelithiation reaction is 2-10 h;
under the protective atmosphere, carrying out carbon coating on the pre-lithiated silica powder and a gas-phase organic carbon source to obtain carbon-coated pre-lithiated silica powder; the method comprises the following steps:
after the pre-lithiation reaction, continuously and uniformly heating to the temperature of 700-850 ℃ in a protective atmosphere, introducing a gas-phase organic carbon source for carbon coating, and cooling to obtain carbon-coated pre-lithiated silica powder;
removing metal salt in the carbon-coated pre-lithiated silica powder to obtain a pre-lithiated silica composite material; the method comprises the following steps:
and washing the carbon-coated pre-lithiated silica powder with water to remove metal salts to obtain the pre-lithiated silica composite material.
5. The method of preparing a pre-lithiated silica-oxygen composite material according to claim 4, wherein the mass ratio of the silica powder to the metal salt is 100:8 to 25; or the mass ratio of the silicon monoxide powder to the metal salt is 100: 10-20;
the mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 50-85; or the mol ratio of the pre-lithiation reagent to the silicon monoxide powder is 100: 60-82.5.
6. The method of preparing a prelithiated silicone oxygen composite material of claim 5, wherein said metal salt comprises LiCl, BiCl3、TiCl4、PbCl2、ZnCl2、MgCl2、LiBr、NaBr、KBr、TiBr4、PbBr2And Na2B4O7Any one or more of;
or the metal salt comprises any one of the following combinations expressed in mass percent:
80％BaCl2+20％NaCl；
50％BaCl2+50％NaCl；
45％NaCl+55％KCl；
30％KCl+20％NaCl+50％BaCl2；
21％NaCl+31％BaCl2+48％CaCl2。
7. the method of preparing a prelithiated silicone-oxygen composite material of claim 2, wherein said prelithiation reagent comprises a compound capable of decomposing out elemental Li; or the prelithiation reagent comprises LiH, LiNH2、LiBH4And Li3One or more of N.
8. The method of preparing a prelithiated silica composite material as recited in any of claims 1-7, wherein the carbon coating temperature is 700-; the carbon coating amount in the carbon-coated pre-lithiated silica powder is 2.5 to 5.5 percent; the oxygen content in the protective atmosphere is less than or equal to 5 ppm.
9. A prelithiated silica composite material prepared by the method of any one of claims 1 to 8, comprising:
a silicon sub-oxide layer;
the carbon coating layer is coated outside the silicon monoxide layer; and a lithium metasilicate layer between the silicon monoxide layer and the carbon coating layer.
10. Use of the pre-lithiated silica-oxygen composite material prepared by the preparation method of any one of claims 1 to 8 or the pre-lithiated silica-oxygen composite material of claim 9 in the preparation of silica negative electrode materials of lithium ion batteries.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210085959.4A CN114497497B (en) | 2022-01-25 | 2022-01-25 | Pre-lithiated silica composite material, preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210085959.4A CN114497497B (en) | 2022-01-25 | 2022-01-25 | Pre-lithiated silica composite material, preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114497497A true CN114497497A (en) | 2022-05-13 |
| CN114497497B CN114497497B (en) | 2024-04-12 |
Family
ID=81474431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210085959.4A Active CN114497497B (en) | 2022-01-25 | 2022-01-25 | Pre-lithiated silica composite material, preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114497497B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114975950A (en) * | 2022-06-14 | 2022-08-30 | 雅安天蓝新材料科技有限公司 | Carbon-silicon composite material and preparation method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102569726A (en) * | 2010-12-30 | 2012-07-11 | 中国电子科技集团公司第十八研究所 | Method for preparing lithium ion battery anode material coated with metal ions |
| CN104201324A (en) * | 2014-07-31 | 2014-12-10 | 山东海特电子新材料有限公司 | Method for synthesizing lithium nickel cobalt manganese oxide used as anode material for lithium ion battery by template method |
| WO2018161821A1 (en) * | 2017-03-06 | 2018-09-13 | 深圳市贝特瑞新能源材料股份有限公司 | Compound, preparation method therefore, and use in lithium ion secondary battery |
| CN109524650A (en) * | 2018-11-13 | 2019-03-26 | 东莞市凯金新能源科技股份有限公司 | A kind of lithium ion battery silicon monoxide composite cathode material and preparation method |
| CN111133613A (en) * | 2017-10-19 | 2020-05-08 | 株式会社Lg化学 | Negative electrode active material, negative electrode including the same, and secondary battery including the negative electrode |
| WO2020103914A1 (en) * | 2018-11-24 | 2020-05-28 | 华为技术有限公司 | Silicon oxygen composite negative electrode material and fabrication method therefor |
| CN111900369A (en) * | 2020-07-24 | 2020-11-06 | 陕西煤业化工技术研究院有限责任公司 | Pre-lithiated silicon oxide/carbon composite material and preparation method and application thereof |
| CN113036108A (en) * | 2021-03-11 | 2021-06-25 | 昆山宝创新能源科技有限公司 | Negative electrode material and preparation method and application thereof |
-
2022
- 2022-01-25 CN CN202210085959.4A patent/CN114497497B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102569726A (en) * | 2010-12-30 | 2012-07-11 | 中国电子科技集团公司第十八研究所 | Method for preparing lithium ion battery anode material coated with metal ions |
| CN104201324A (en) * | 2014-07-31 | 2014-12-10 | 山东海特电子新材料有限公司 | Method for synthesizing lithium nickel cobalt manganese oxide used as anode material for lithium ion battery by template method |
| WO2018161821A1 (en) * | 2017-03-06 | 2018-09-13 | 深圳市贝特瑞新能源材料股份有限公司 | Compound, preparation method therefore, and use in lithium ion secondary battery |
| CN111133613A (en) * | 2017-10-19 | 2020-05-08 | 株式会社Lg化学 | Negative electrode active material, negative electrode including the same, and secondary battery including the negative electrode |
| CN109524650A (en) * | 2018-11-13 | 2019-03-26 | 东莞市凯金新能源科技股份有限公司 | A kind of lithium ion battery silicon monoxide composite cathode material and preparation method |
| WO2020103914A1 (en) * | 2018-11-24 | 2020-05-28 | 华为技术有限公司 | Silicon oxygen composite negative electrode material and fabrication method therefor |
| CN111900369A (en) * | 2020-07-24 | 2020-11-06 | 陕西煤业化工技术研究院有限责任公司 | Pre-lithiated silicon oxide/carbon composite material and preparation method and application thereof |
| CN113036108A (en) * | 2021-03-11 | 2021-06-25 | 昆山宝创新能源科技有限公司 | Negative electrode material and preparation method and application thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114975950A (en) * | 2022-06-14 | 2022-08-30 | 雅安天蓝新材料科技有限公司 | Carbon-silicon composite material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114497497B (en) | 2024-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111180691B (en) | Double-layer carbon-coated silicon-based composite material and preparation method and application thereof | |
| JP7288059B2 (en) | Silicon-oxygen composite negative electrode material, its preparation method and lithium ion battery | |
| CN111048770B (en) | Ternary doped silicon-based composite material and preparation method and application thereof | |
| CN111180692B (en) | Negative electrode active material for battery and preparation method thereof | |
| KR102286231B1 (en) | Lithium doped silicon oxide negative active material, method of preparing the same, negative electrode including the same and lithium secondary battery including the same | |
| CN111342031B (en) | Multi-element gradient composite high-first-efficiency lithium battery negative electrode material and preparation method thereof | |
| CN113764642A (en) | Lithium-silicon oxide-containing composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN108666560A (en) | Lithium ion battery, nano silicon material and preparation method thereof | |
| JP2023550073A (en) | Silicon-based particles with core-shell structure and their manufacturing method, negative electrode materials, pole pieces and batteries | |
| CN113363430A (en) | Soft carbon coated boron-doped silicon-based negative electrode material and preparation method and application thereof | |
| CN114464790A (en) | Pre-lithiated silica composite material, preparation method and application | |
| CN116565174A (en) | Silicon-carbon composite material, preparation method, silicon-based negative electrode and lithium ion battery | |
| CN114497497B (en) | Pre-lithiated silica composite material, preparation method and application | |
| CN114204006B (en) | Battery negative electrode active material, preparation method thereof, battery negative electrode and secondary battery | |
| CN114373915B (en) | Silicon oxide negative electrode material and preparation method thereof | |
| CN116230933A (en) | Method for removing alkali from surface of pre-lithiated anode material | |
| WO2022042266A1 (en) | Silicon-oxygen composite negative electrode material, preparation method therefor, and lithium ion battery | |
| CN114784233A (en) | Negative electrode active material and preparation method and application thereof | |
| CN114079050A (en) | Silica composite material, preparation method thereof, negative electrode material and lithium ion battery | |
| CN114725345B (en) | Preparation method and application of Fe3O4/NaTi2 (PO 4) 3/C micro-nano composite material | |
| CN114864915B (en) | Preparation method of porous silicon/carbon nano tube composite material | |
| WO2024108574A1 (en) | Carbon material and preparation method therefor, and secondary battery and electric device comprising same | |
| WO2023197097A1 (en) | Silicon-carbon composite material, method for preparing silicon-carbon composite material, negative electrode sheet, and electrochemical device | |
| CN115881934A (en) | Silicon negative electrode material for lithium ion battery and preparation method thereof | |
| CN116387491A (en) | Silicon-based composite anode material and preparation method and application thereof |
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 |