CN114551886B - Composite negative electrode material, preparation method thereof and lithium ion battery - Google Patents
Composite negative electrode material, preparation method thereof and lithium ion battery Download PDFInfo
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- 239000002131 composite material Substances 0.000 title claims abstract description 66
- 238000002360 preparation method Methods 0.000 title claims abstract description 47
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 20
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 20
- 239000007773 negative electrode material Substances 0.000 title description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 155
- 239000005543 nano-size silicon particle Substances 0.000 claims abstract description 77
- 239000010405 anode material Substances 0.000 claims abstract description 69
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 69
- 238000000034 method Methods 0.000 claims abstract description 58
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 51
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 40
- 238000002156 mixing Methods 0.000 claims abstract description 38
- 238000006722 reduction reaction Methods 0.000 claims abstract description 30
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000002243 precursor Substances 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims abstract description 24
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 14
- 230000009467 reduction Effects 0.000 claims abstract description 11
- 238000006243 chemical reaction Methods 0.000 claims description 31
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 28
- 238000005406 washing Methods 0.000 claims description 28
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 26
- 238000003756 stirring Methods 0.000 claims description 25
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 24
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 22
- 229910052710 silicon Inorganic materials 0.000 claims description 19
- 239000010703 silicon Substances 0.000 claims description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 19
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 claims description 18
- 239000003054 catalyst Substances 0.000 claims description 18
- 230000007062 hydrolysis Effects 0.000 claims description 18
- 238000006460 hydrolysis reaction Methods 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 17
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 16
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 16
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 16
- 239000002904 solvent Substances 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 14
- -1 aldehyde compound Chemical class 0.000 claims description 14
- 229910052786 argon Inorganic materials 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 13
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 12
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 12
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical compound OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 claims description 12
- 238000001035 drying Methods 0.000 claims description 12
- 239000001257 hydrogen Substances 0.000 claims description 11
- 229910052739 hydrogen Inorganic materials 0.000 claims description 11
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 11
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 claims description 10
- 150000003839 salts Chemical class 0.000 claims description 10
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 9
- JFCCVNTYPIUJDJ-UHFFFAOYSA-N methyl-tris(prop-2-enyl)silane Chemical compound C=CC[Si](C)(CC=C)CC=C JFCCVNTYPIUJDJ-UHFFFAOYSA-N 0.000 claims description 9
- 229910017604 nitric acid Inorganic materials 0.000 claims description 9
- QQQSFSZALRVCSZ-UHFFFAOYSA-N triethoxysilane Chemical compound CCO[SiH](OCC)OCC QQQSFSZALRVCSZ-UHFFFAOYSA-N 0.000 claims description 9
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 8
- 238000005554 pickling Methods 0.000 claims description 8
- 239000011780 sodium chloride Substances 0.000 claims description 8
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 claims description 7
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 7
- 239000001307 helium Substances 0.000 claims description 7
- 229910052734 helium Inorganic materials 0.000 claims description 7
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 7
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 7
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 7
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 claims description 7
- RYYKJJJTJZKILX-UHFFFAOYSA-M sodium octadecanoate Chemical compound [Na+].CCCCCCCCCCCCCCCCCC([O-])=O RYYKJJJTJZKILX-UHFFFAOYSA-M 0.000 claims description 7
- 239000004094 surface-active agent Substances 0.000 claims description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 6
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 4
- 229920001296 polysiloxane Polymers 0.000 claims description 4
- 238000000227 grinding Methods 0.000 claims description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- 230000008569 process Effects 0.000 abstract description 15
- 239000011777 magnesium Substances 0.000 abstract description 14
- 229910052749 magnesium Inorganic materials 0.000 abstract description 14
- 230000002829 reductive effect Effects 0.000 abstract description 11
- 239000000463 material Substances 0.000 abstract description 10
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 abstract description 8
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 abstract description 7
- 230000000694 effects Effects 0.000 abstract description 7
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 abstract description 7
- 229910010271 silicon carbide Inorganic materials 0.000 abstract description 7
- 238000009830 intercalation Methods 0.000 abstract description 6
- 230000002687 intercalation Effects 0.000 abstract description 6
- 239000003638 chemical reducing agent Substances 0.000 abstract description 5
- 239000007772 electrode material Substances 0.000 abstract description 5
- 238000005265 energy consumption Methods 0.000 abstract description 5
- ZVLDJSZFKQJMKD-UHFFFAOYSA-N [Li].[Si] Chemical compound [Li].[Si] ZVLDJSZFKQJMKD-UHFFFAOYSA-N 0.000 abstract description 4
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 4
- 239000000395 magnesium oxide Substances 0.000 abstract description 4
- 239000000243 solution Substances 0.000 description 47
- 235000011114 ammonium hydroxide Nutrition 0.000 description 22
- 239000002253 acid Substances 0.000 description 16
- 239000008367 deionised water Substances 0.000 description 12
- 229910021641 deionized water Inorganic materials 0.000 description 12
- 239000010439 graphite Substances 0.000 description 11
- 229910002804 graphite Inorganic materials 0.000 description 11
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 10
- WCVHUIPWSPEOIG-UHFFFAOYSA-N n,n-dimethylheptadecan-1-amine Chemical compound CCCCCCCCCCCCCCCCCN(C)C WCVHUIPWSPEOIG-UHFFFAOYSA-N 0.000 description 10
- 239000007788 liquid Substances 0.000 description 9
- 230000002441 reversible effect Effects 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 239000002153 silicon-carbon composite material Substances 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 5
- 150000002431 hydrogen Chemical class 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 4
- 239000002210 silicon-based material Substances 0.000 description 4
- 229960000892 attapulgite Drugs 0.000 description 3
- 238000009831 deintercalation Methods 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 229910052625 palygorskite Inorganic materials 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000011946 reduction process Methods 0.000 description 3
- 239000011863 silicon-based powder Substances 0.000 description 3
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 238000003763 carbonization Methods 0.000 description 2
- 239000010406 cathode material Substances 0.000 description 2
- 229910021419 crystalline silicon Inorganic materials 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- FHVDTGUDJYJELY-UHFFFAOYSA-N 6-{[2-carboxy-4,5-dihydroxy-6-(phosphanyloxy)oxan-3-yl]oxy}-4,5-dihydroxy-3-phosphanyloxane-2-carboxylic acid Chemical compound O1C(C(O)=O)C(P)C(O)C(O)C1OC1C(C(O)=O)OC(OP)C(O)C1O FHVDTGUDJYJELY-UHFFFAOYSA-N 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229920002153 Hydroxypropyl cellulose Polymers 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 229940072056 alginate Drugs 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 229910003481 amorphous carbon Inorganic materials 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000001863 hydroxypropyl cellulose Substances 0.000 description 1
- 235000010977 hydroxypropyl cellulose Nutrition 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000006138 lithiation reaction Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 229920002285 poly(styrene-co-acrylonitrile) Polymers 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000011856 silicon-based particle Substances 0.000 description 1
- 239000011870 silicon-carbon composite anode material Substances 0.000 description 1
- 239000011868 silicon-carbon composite negative electrode material Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 238000003828 vacuum filtration Methods 0.000 description 1
- 239000011800 void material Substances 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
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- 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
- H01M4/36—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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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 provides a composite anode material, a preparation method thereof and a lithium ion battery, wherein the preparation method comprises the following steps: mixing a carbon source solution, a silicon dioxide solution and a reducing agent to obtain a precursor; mixing a magnesium source with the obtained precursor, and heating and reducing to obtain the composite anode material. The invention simplifies the preparation of the carbon-coated nano-silicon anode material by two-step magnesia reduction, prepares the carbon-coated nano-silicon anode material by one-step magnesia reduction reaction, reduces the energy consumption, reduces the process flow and is easy for large-scale production; meanwhile, the influence of volume expansion in the process of silicon lithium intercalation is reduced, and the stability of the structure of the anode material is maintained; the impedance is reduced, the activity of the electrode material is improved, and the cycle performance of the material is improved. According to the composite anode material provided by the invention, silicon carbide is generated at the silicon-carbon interface, so that the structural stability of the composite anode material is further maintained.
Description
Technical Field
The invention belongs to the technical field of lithium ion battery materials, relates to a preparation method of a composite negative electrode material, and particularly relates to a composite negative electrode material, a preparation method thereof and a lithium ion battery.
Background
In recent years, the key of new energy automobiles is to improve the energy density and the service life under the premise of the same safety. At present, the commercial graphite cathode has the theoretical specific capacity of 372mAh/g, so that the requirement of people on a high-energy density lithium ion battery is difficult to meet, and silicon becomes one of the most promising cathode materials at present due to the highest theoretical specific capacity, so that the commercial graphite cathode is widely paid attention to by researchers.
The charging and discharging mechanism of the silicon anode material is different from that of the traditional rocking chair battery by the way of carrying out charging and discharging through embedding and releasing reaction, but is closer to alloying reaction. The final product of lithiation of the silicon negative electrode is Li x Si, x=3-4.4. Because of alloying reaction, the lithiated lithium and silicon element has the highest theoretical specific capacity compared with the silicon cathode used for the lithium ion battery, and the mass specific energy of the lithium ion battery is greatly improved. However, the repeated change of the volume of silicon in the lithium intercalation process generates larger internal stress, so that active substances are pulverized to cause the material to fall off. In addition, the volume of the silicon particles changes to destroy the conductive network of the composite electrode, a solid electrolyte interface film (SEI film) formed on the surface of the material is unstable, more electrolyte is consumed in the circulation process, and the capacity of the battery is rapidly attenuated, so that the commercialized application of silicon is limited. Li by silicon nanocrystallization to alleviate the above problems, alleviate volume changes, and shorten + A transmission path. However, the silicon material with nano structure has more irreversible reaction and lower tap density due to the high specific surface area, and is not suitable for single use and needs to be further improved. One of the commonly used methods of modifying silicon cathodes is the compounding of silicon carbon materials. The carbon material not only has excellent conductivity and higher electrochemical activity, but also has good compatibility with the silicon material, so that the silicon anode material is the first choice for modification.
CN 111834610a discloses a preparation method of lithium ion battery silicon-carbon composite negative electrode material based on magnesian reduction, which comprises the steps of firstly preparing high-concentration graphite dispersion liquid by adopting graphite and carboxymethyl cellulose or hydroxypropyl cellulose solution, then adding nano silica sol into the graphite dispersion liquid to uniformly disperse the nano silica sol, then spray-drying the dispersion liquid to form graphite/silica composite, then carrying out magnesian reduction reaction, finally adding styrene-acrylonitrile copolymer emulsion and carrying out high-temperature treatment to obtain the lithium ion battery silicon-carbon composite material. The prepared silicon-carbon composite material of the lithium ion battery has good conductivity, high dispersion degree of graphite and silicon, high battery capacity and good cycle life.
CN 111244414a discloses a method for preparing silicon-carbon negative electrode material by magnesian reduction, which comprises the following steps: roasting the micro silicon powder, dispersing the micro silicon powder in acid etching liquid, heating in water bath, and performing suction filtration, water washing and drying to obtain a pretreated sample; mixing the pretreated sample and magnesium powder through ball milling, naturally drying, placing the mixture in a sealed graphite crucible, transferring the sealed graphite crucible into a tube furnace of inert gas, performing magnesium thermal reaction, and obtaining a product which is subjected to acid washing, vacuum filtration, water washing and drying to obtain Kong Jinggui; and uniformly mixing the prepared porous crystalline silicon with an organic precursor, drying, and then placing in protective gas for curing treatment to obtain the silicon-based composite material. The porous crystalline silicon is obtained through acid etching pretreatment and magnesian reduction treatment of the micro silicon powder; the silicon material not only has higher specific capacity, but also forms a porous structure which plays a role in buffering the volume expansion of the silicon material; on the other hand, the depth and the diffusion distance of lithium ion deintercalation are shortened, so that the lithium ion deintercalation device has excellent electrochemical performance.
CN 112436131a discloses a method for preparing a silicon-carbon composite material by using molten salt to assist in magnesium thermal reduction, which comprises the steps of firstly carbonizing alginate and attapulgite serving as raw materials at high temperature to obtain an amorphous carbon coating coated with the attapulgite composite material, then adding a reducing agent and molten salt to perform thermal assisted reduction reaction, and carrying out acid washing treatment to obtain the silicon-carbon composite material. The method for preparing the silicon-carbon composite material by combining high-temperature carbonization and low-temperature molten salt heat assisted reduction reaction effectively reduces the generation of silicon carbide, and the prepared silicon-carbon composite material has a carbon coating which coats silicon nano particles reduced by attapulgite and forms a void structure by acid etching. The composite material is used for a lithium ion battery cathode material, and the carbon layer, the gaps and the porous structure can effectively relieve the volume expansion effect caused in the lithium intercalation and deintercalation process, and simultaneously improve the electronic conductivity, so that the composite material has excellent electrochemical lithium storage performance.
The silicon-carbon composite anode material is prepared by the magnesium thermal reduction reaction in the technical scheme, however, the magnesium thermal reaction method adopted at present is mainly that the reduction reaction of silicon and the carbonization reaction of a carbon source are carried out separately: the silicon dioxide material is reduced into silicon and the coated carbon source are separately carried out, then high-temperature reaction is carried out, and the carbon source precursor material is carbonized to obtain the silicon-carbon composite material.
In view of the above, how to improve the preparation process, shorten the preparation flow, simplify the preparation method, and simultaneously ensure the excellent electrochemical performance of the composite anode material is a technical problem to be solved in the field of anode materials of lithium ion batteries.
Disclosure of Invention
In order to solve the technical problems, the invention provides a composite anode material, a preparation method thereof and a lithium ion battery, and provides a method for preparing carbon-coated nano silicon by one-step magnesia-thermal reduction, wherein the traditional commonly used two-step high-temperature reaction is degenerated into one-step reaction, meanwhile, the influence of volume expansion in the process of embedding lithium into silicon is reduced, the stability of the structure of the electrode material is maintained, the preparation process is simplified, the energy consumption is reduced, the environment is friendly, and the cost is low.
In a first aspect, the present invention provides a method for preparing a composite anode material, the method comprising the steps of:
(1) Mixing a carbon source solution, a silicon dioxide solution and a reducing agent to obtain a precursor;
(2) Mixing a magnesium source with the precursor obtained in the step (1), and heating and reducing to obtain the composite anode material.
The invention simplifies the two-step method for preparing the carbon-coated nano silicon anode material by magnesian reduction, realizes the preparation of the carbon-coated nano silicon anode material by one-step magnesian reduction reaction, reduces the energy consumption, reduces the process flow and is easy for large-scale production. Meanwhile, the preparation method provided by the invention reduces the influence of volume expansion in the process of silicon lithium intercalation, and maintains the stability of the structure of the anode material. The conductive performance of the negative electrode is improved by coating the carbon material on the outermost layer, the impedance is reduced, the activity of the electrode material is improved, and the cycle performance of the material is improved; according to the composite anode material provided by the invention, silicon carbide is generated at the silicon-carbon interface, so that the structural stability of the composite anode material is further maintained.
Preferably, the carbon source solution of step (1) comprises a carbon source, a solvent and a hydrolysis catalyst.
Preferably, the carbon source comprises any one or a combination of at least two of m-diphenol, polyvinylpyrrolidone, o-diphenol, p-diphenol, or a-phenol naphthalene, and typical but non-limiting combinations include combinations of m-diphenol and polyvinylpyrrolidone, combinations of polyvinylpyrrolidone and o-diphenol, combinations of o-diphenol and p-diphenol, combinations of p-diphenol and a-phenol naphthalene, combinations of m-diphenol and polyvinylpyrrolidone, o-diphenol, combinations of polyvinylpyrrolidone, o-diphenol and p-diphenol, or combinations of o-diphenol, p-diphenol and a-phenol naphthalene, preferably m-diphenol.
Preferably, the concentration of the carbon source in the carbon source solution in the step (1) is 5-10mg/ml, and for example, may be 5mg/ml, 6mg/ml, 7mg/ml, 8mg/ml, 9mg/ml or 10mg/ml, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the solvent comprises methanol and/or ethanol.
Preferably, the hydrolysis catalyst comprises aqueous ammonia.
Preferably, the concentration of the hydrolysis catalyst in the carbon source solution in step (1) is 2-3mg/ml, and may be, for example, 2mg/ml, 2.2mg/ml, 2.4mg/ml, 2.6mg/ml, 2.8mg/ml or 3mg/ml, but not limited to the values recited, and other values not recited in the numerical range are equally applicable.
Preferably, the silica solution of step (1) comprises water, a surfactant and silica.
Preferably, the surfactant comprises any one or a combination of at least two of cetyltrimethyl-amine bromide, sodium stearate or sodium dodecylbenzene sulfonate, typical but non-limiting combinations include cetyltrimethyl-amine bromide in combination with sodium stearate, sodium stearate in combination with sodium dodecylbenzene sulfonate, cetyltrimethyl-amine bromide in combination with sodium dodecylbenzene sulfonate, or cetyltrimethyl-amine bromide, sodium stearate in combination with sodium dodecylbenzene sulfonate.
Preferably, the concentration of the surfactant is 0.03-0.04g/mL, for example, 0.03g/mL, 0.031g/mL, 0.032g/mL, 0.034g/mL, 0.036g/mL, 0.038g/mL, or 0.04g/mL, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.
The silica concentration is preferably 0.01 to 0.015g/mL, and may be, for example, 0.01g/mL, 0.011g/mL, 0.012g/mL, 0.013g/mL, 0.014g/mL, or 0.015g/mL, although not limited to the values recited, and other non-recited values within the range of values are equally applicable.
Preferably, the silica comprises nanosilica.
Preferably, the nano-silica has a particle size ranging from 200 to 500nm, for example, 200nm, 250nm, 300nm, 400nm, 450nm or 500nm, but not limited to the recited values, and other non-recited values within the range are equally applicable.
When the particle size range of the nano silicon dioxide is larger than 500nm, the particle size of the reduced silicon is too large, the surface is difficult to form uniform coating, and when the particle size range of the nano silicon dioxide is smaller than 200nm, the reduced product is easy to agglomerate.
Preferably, the preparation method of the nano silicon dioxide comprises the following steps: mixing the organosilicon source solution and the hydrolysis catalyst solution, centrifuging, washing and drying to obtain the nano silicon dioxide.
The preparation process of the nano silicon dioxide provided by the invention is simple, the morphology and the particle size are controllable, and the nano SiO is easy to obtain 2 The microspheres and the particles are dispersed and uniform in size, and are favorable for realizing uniform coating with a carbon source.
Preferably, the organosilicon source comprises any one or a combination of at least two of ethyl orthosilicate, diallyl phenyldimethylsilane, triethoxysilane, or methyltriallylsilane, including typically, but not limited to, a combination of ethyl orthosilicate and diallyl phenyldimethylsilane, a combination of diallyl phenyldimethylsilane and triethoxysilane, a combination of triethoxysilane and methyltriallylsilane, a combination of ethyl orthosilicate, diallyl phenyldimethylsilane and triethoxysilane, or a combination of diallyl phenyldimethylsilane, triethoxysilane, and methyltriallylsilane, preferably ethyl orthosilicate.
Preferably, the solvent of the silicone source solution comprises an alcohol.
Preferably, the concentration of the silicone source in the silicone source solution is from 0.02 to 0.04g/ml, and may be, for example, 0.02g/ml, 0.025g/ml, 0.03g/ml, 0.035g/ml, or 0.04g/ml, although not limited to the values recited, other non-recited values within the range of values are equally applicable.
Preferably, the hydrolysis catalyst comprises aqueous ammonia.
Preferably, the solvent in the hydrolysis catalyst solution comprises a hydroalcoholic mixture.
Preferably, the volume ratio of water to alcohol in the hydroalcoholic mixed solution is 1 (2-3), for example, may be 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:2.9 or 1:3, but is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the concentration of the hydrolysis catalyst in the hydrolysis catalyst solution is between 0.3 and 0.4mg/ml, and may be, for example, 0.3mg/ml, 0.32mg/ml, 0.34mg/ml, 0.36mg/ml, 0.38mg/ml or 0.4mg/ml, but is not limited to the values recited, as are other non-recited values within the range of values.
Preferably, the means of mixing comprises stirring.
Preferably, the stirring time is 4-6 hours, for example, 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the stirring speed is 500-700r/min, for example, 500r/min, 550r/min, 600r/min, 650r/min or 700r/min, but the stirring speed is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the reducing agent of step (1) comprises an aldehyde compound, preferably formaldehyde and/or acetaldehyde.
Preferably, the volume ratio of the carbon source solution, the silica solution and the reducing agent in the step (1) is 1 (9-12): (4-6), for example, may be 1:9:4, 1:10:5, 1:12:6, 1:12:4 or 1:9:6, but is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the means of mixing in step (1) comprises ultrasonic dispersion and/or stirring.
Preferably, the time of the ultrasonic dispersion is 20-40min, for example, 20min, 25min, 30min, 35min or 40min, but not limited to the recited values, and other non-recited values in the range of values are equally applicable.
Preferably, the temperature of the stirring is 30-50 ℃, for example, 30 ℃, 35 ℃,40 ℃, 45 ℃ or 50 ℃, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the stirring time is 6-10h, for example, 6h, 6.5h, 7h, 8h, 9h or 10h, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the magnesium source of step (2) comprises magnesium powder.
Preferably, the mixing of step (2) further comprises mixing a salt. The salt is NaCl and/or CaCl 2 。
In the magnesium reduction reaction, the effect of adding salt: used as a heat absorbing agent to avoid the rapid increase of internal temperature.
Preferably, the mass ratio of the magnesium source, the precursor and the salt obtained in step (2) is (0.8-1.2): 1 (9-11), and may be, for example, 0.8:1:9, 1.2:1:11, 1:1:10, 0.8:1:11 or 1.2:1:9, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the mixing in step (2) further comprises grinding.
Preferably, the mixed gas is introduced in the temperature rising reduction process of the step (2).
Preferably, the mixture comprises at least two of hydrogen, argon, helium, or nitrogen, typically but not limited to combinations comprising hydrogen and argon, argon and helium, helium and nitrogen, hydrogen, argon and helium, argon, helium and nitrogen, or hydrogen, argon, helium and nitrogen.
Due to the large amount of heat released by the magnesium thermal reaction, a small amount of silicon carbide is generated at the silicon-carbon interface. The silicon carbide is favorable for protecting the overall structural stability of the material, and the new surface is prevented from contacting electrolyte to generate a new SEI film after the structure is broken.
Preferably, the gas flow rate of the gas is 0.02-0.05L/min, for example, 0.02L/min, 0.03L/min, 0.04L/min, 0.045L/min or 0.05L/min, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the heating rate of the heating in the step (2) is 2-10 ℃/min, for example, 2 ℃/min, 3 ℃/min, 5 ℃/min, 6 ℃/min, 8 ℃/min, 9 ℃/min or 10 ℃/min, but the heating rate is not limited to the recited values, and other values not recited in the numerical range are equally applicable.
Preferably, the reaction temperature of the reduction in step (2) is 600-800 ℃, for example 600 ℃, 650 ℃, 700 ℃, 750 ℃ or 800 ℃, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the temperature-raising reduction process of step (2) is completed by acid washing.
Preferably, the pickling solution comprises any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid, typically but not limited to a combination of hydrochloric acid and sulfuric acid, a combination of sulfuric acid and nitric acid, a combination of nitric acid and phosphoric acid, a combination of hydrochloric acid, sulfuric acid and nitric acid, a combination of sulfuric acid, nitric acid and phosphoric acid, or a combination of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.
As a preferred technical scheme of the preparation method according to the first aspect of the present invention, the preparation method comprises the following steps:
(1) Mixing the carbon source solution, the nano silicon dioxide solution and the aldehyde compound in the volume ratio of (9-12) (4-6), wherein the concentration of the carbon source is 5-10mg/mL, the concentration of the hydrolysis catalyst in the carbon source solution is 2-3mg/mL, the concentration of the nano silicon dioxide is 0.01-0.015g/mL, the ultrasonic dispersion is carried out for 20-40min, and the stirring is carried out for 6-10h at the temperature of 30-50 ℃ to obtain a precursor;
the preparation method of the nano silicon dioxide comprises the following steps: mixing an organosilicon source solution and a hydrolysis catalyst solution, wherein the concentration of the organosilicon source is 0.02-0.04g/ml, the concentration of the hydrolysis catalyst is 0.3-0.4mg/ml, stirring for 4-6h at the rotating speed of 500-700r/min, centrifuging, washing and drying to obtain the nano silicon dioxide;
(2) 1 (9-11) magnesium powder, the obtained precursor and salt, introducing mixed gas with the flow of 0.02-0.05L/min, heating at 2-10 ℃/min, heating to the reaction temperature of 600-800 ℃ for reduction reaction, and pickling after the reaction is finished to obtain the composite anode material;
the carbon source comprises any one or a combination of at least two of m-diphenol, polyvinylpyrrolidone, o-diphenol, p-diphenol or a-phenol naphthalene; the particle size range of the nano silicon dioxide is 200-500nm; the organosilicon source comprises any one or a combination of at least two of tetraethoxysilane, diallyl phenyl dimethyl silane, triethoxysilane or methyltriallylsilane.
In a second aspect, the present invention provides a composite anode material obtainable by the method of preparation according to the first aspect.
In a third aspect, the present invention provides a lithium ion battery comprising a composite anode material as described in the second aspect.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention simplifies the traditional two-step method for preparing the carbon-coated nano-silicon anode material by magnesian reduction, realizes the preparation of the carbon-coated nano-silicon anode material by one-step magnesian reduction reaction, reduces the energy consumption, reduces the process flow and is easy for large-scale production. Meanwhile, the preparation method provided by the invention reduces the influence of volume expansion in the process of silicon lithium intercalation, and maintains the stability of the structure of the anode material. The conductive performance of the negative electrode is improved by coating the carbon material on the outermost layer, the impedance is reduced, the activity of the electrode material is improved, and the cycle performance of the material is improved; according to the composite anode material provided by the invention, silicon carbide is generated at the silicon-carbon interface, so that the structural stability of the composite anode material is further maintained.
Detailed Description
To facilitate understanding of the present invention, examples are set forth below. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
Example 1
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing a meta-diphenol solution, a nano silicon dioxide solution and acetaldehyde in a volume ratio of 1:10:5, performing ultrasonic dispersion for 30min, and stirring at 40 ℃ for 8 hours to obtain a precursor;
the m-diphenol solution comprises m-diphenol, an ethanol solvent and ammonia water, wherein the concentration of the m-diphenol is 8mg/ml, and the concentration of the ammonia water is 2.5mg/ml;
the preparation method of the nano silicon dioxide comprises the following steps: mixing ethyl orthosilicate and ammonia water in an ethanol solvent, wherein the concentration of the obtained ethyl orthosilicate is 0.03g/ml, the concentration of the ammonia water is 0.35mg/ml, stirring for 5 hours at the rotating speed of 600r/min, washing with deionized water, and drying to obtain the nano silicon dioxide, wherein the particle size range of the nano silicon dioxide is 200-500nm;
the nano silicon dioxide solution consists of deionized water, hexadecyl trimethyl amine bromide and nano silicon dioxide, wherein the concentration of the hexadecyl trimethyl amine bromide is 0.035g/mL, and the concentration of the nano silicon dioxide is 0.012g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride in a mass ratio of 1:1:10, introducing argon and hydrogen mixed gas with a flow of 0.04L/min, heating at a speed of 7 ℃/min, heating to a reaction temperature of 700 ℃ for reduction reaction, and pickling after the reaction is finished, wherein the pickling solution is hydrochloric acid, so that the composite anode material is obtained.
Example 2
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing a meta-diphenol solution, a nano silicon dioxide solution and formaldehyde in a volume ratio of 1:9:4, performing ultrasonic dispersion for 20min, and stirring for 6h at 50 ℃ to obtain a precursor;
the m-diphenol solution comprises m-diphenol, an ethanol solvent and ammonia water, wherein the concentration of the m-diphenol is 6mg/ml, and the concentration of the ammonia water is 2.8mg/ml;
the preparation method of the nano silicon dioxide comprises the following steps: mixing diallyl phenyl dimethyl silane and ammonia water in ethanol, wherein the concentration of the obtained diallyl phenyl dimethyl silane is 0.025g/ml, the concentration of the ammonia water is 0.3mg/ml, stirring for 6 hours at a rotating speed of 500r/min, washing with deionized water, and drying to obtain the nano silicon dioxide, wherein the particle size range of the nano silicon dioxide is 200-500nm;
the nano silicon dioxide solution consists of deionized water, sodium stearate and nano silicon dioxide, wherein the concentration of the sodium stearate is 0.03g/mL, and the concentration of the nano silicon dioxide is 0.01g/mL;
(2) Mixing magnesium powder, the obtained precursor and calcium chloride in a mass ratio of 0.8:1:9, introducing argon and nitrogen mixed gas with a flow of 0.02L/min, heating at 2 ℃/min, heating to a reaction temperature of 600 ℃ for reduction reaction, and carrying out acid washing after the reaction is finished, wherein the washing liquid of the acid washing is sulfuric acid, so that the composite anode material is obtained.
Example 3
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing an o-diphenol solution, a nano silicon dioxide solution and formaldehyde in a volume ratio of 1:12:6, performing ultrasonic dispersion for 40min, and stirring for 6h at 50 ℃ to obtain a precursor;
the o-diphenol solution comprises o-diphenol, ethanol solvent and ammonia water, wherein the concentration of the o-diphenol is 10mg/ml, and the concentration of the ammonia water is 3mg/ml;
the preparation method of the nano silicon dioxide comprises the following steps: mixing triethoxysilane and ammonia water in ethanol, wherein the concentration of the triethoxysilane is 0.04g/ml, the concentration of the ammonia water is 0.4mg/ml, stirring for 6 hours at a rotating speed of 700r/min, washing with deionized water, and drying to obtain the nano silicon dioxide, wherein the particle size range of the nano silicon dioxide is 200-500nm;
the nano silicon dioxide solution consists of deionized water, sodium dodecyl benzene sulfonate and nano silicon dioxide, wherein the concentration of the sodium dodecyl benzene sulfonate is 0.04g/mL, and the concentration of the nano silicon dioxide is 0.015g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride in a mass ratio of 1.2:1:11, introducing a mixed gas of nitrogen and hydrogen with a flow of 0.05L/min, heating at a speed of 10 ℃/min, heating to a reaction temperature of 800 ℃ for reduction reaction, and carrying out acid washing after the reaction is finished, wherein the washing liquid of the acid washing is phosphoric acid, so as to obtain the composite anode material.
Example 4
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing a paradiphenol solution, a nano silicon dioxide solution and acetaldehyde in a volume ratio of 1:12:4, performing ultrasonic dispersion for 30min, and stirring at 40 ℃ for 8 hours to obtain a precursor;
the para-diphenol solution comprises para-diphenol, ethanol solvent and ammonia water, wherein the concentration of the para-diphenol is 9mg/ml, and the concentration of the ammonia water is 2.2mg/ml;
the preparation method of the nano silicon dioxide comprises the following steps: mixing methyltriallyl silane and ammonia water in an ethanol solvent, wherein the concentration of the obtained methyltriallyl silane is 0.02g/ml, the concentration of the ammonia water is 0.4mg/ml, stirring for 5 hours at a rotating speed of 600r/min, washing with deionized water, and drying to obtain nano silicon dioxide, wherein the particle size range of the nano silicon dioxide is 200-500nm;
the nano silicon dioxide solution consists of deionized water, hexadecyl trimethyl amine bromide and nano silicon dioxide, wherein the concentration of the hexadecyl trimethyl amine bromide is 0.03g/mL, and the concentration of the nano silicon dioxide is 0.01g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride in a mass ratio of 0.8:1:11, introducing argon and hydrogen mixed gas with a flow of 0.04L/min, heating at a speed of 7 ℃/min, heating to a reaction temperature of 700 ℃ for reduction reaction, and carrying out acid washing after the reaction is finished, wherein the washing liquid of the acid washing is nitric acid, so as to obtain the composite anode material.
Example 5
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing a-phenolic naphthalene solution, nano silicon dioxide solution and acetaldehyde in a volume ratio of 1:10:6, performing ultrasonic dispersion for 30min, and stirring at 40 ℃ for 8h to obtain a precursor;
the a-phenol naphthalene solution comprises a-phenol naphthalene, an ethanol solvent and ammonia water, wherein the concentration of the a-phenol naphthalene is 10mg/ml, and the concentration of the ammonia water is 3mg/ml;
the preparation method of the nano silicon dioxide comprises the following steps: mixing methyltriallyl silane and ammonia water in an ethanol solvent, wherein the concentration of the obtained methyltriallyl silane is 0.04g/ml, the concentration of the ammonia water is 0.4mg/ml, stirring for 5 hours at the rotating speed of 600r/min, washing with deionized water, and drying to obtain the nano silicon dioxide, wherein the particle size range of the nano silicon dioxide is 200-500nm;
the nano silicon dioxide solution consists of deionized water, hexadecyl trimethyl amine bromide and nano silicon dioxide, wherein the concentration of the hexadecyl trimethyl amine bromide is 0.035g/mL, and the concentration of the nano silicon dioxide is 0.012g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride in a mass ratio of 1:1:9, introducing argon and hydrogen mixed gas with a flow of 0.05L/min, heating at a speed of 7 ℃/min, heating to a reaction temperature of 700 ℃ for reduction reaction, and pickling after the reaction is finished, wherein the pickling solution is nitric acid, so that the composite anode material is obtained.
Example 6
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing the m-diphenol, the nano silicon dioxide solution and the acetaldehyde, performing ultrasonic dispersion for 30min, and stirring for 8h at the temperature of 40 ℃ to obtain a precursor;
the particle size range of the nano silicon dioxide is 100-200nm;
the nano silicon dioxide solution consists of deionized water, hexadecyl trimethyl amine bromide and nano silicon dioxide, wherein the concentration of the hexadecyl trimethyl amine bromide is 0.035g/mL, and the concentration of the nano silicon dioxide is 0.012g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride, introducing a mixed gas of argon and hydrogen, heating at a speed of 7 ℃/min, heating to a reaction temperature of 700 ℃ for reduction reaction, and carrying out acid washing after the reaction is finished, wherein the washing liquid for acid washing is hydrochloric acid, so that the composite anode material is obtained.
Example 7
The embodiment provides a preparation method of a composite anode material, which comprises the following steps:
(1) Mixing the m-diphenol, the nano silicon dioxide solution and the acetaldehyde, performing ultrasonic dispersion for 30min, and stirring for 8h at the temperature of 40 ℃ to obtain a precursor;
the particle size range of the nano silicon dioxide is 500-1000nm;
the nano silicon dioxide solution consists of deionized water, hexadecyl trimethyl amine bromide and nano silicon dioxide, wherein the concentration of the hexadecyl trimethyl amine bromide is 0.035g/mL, and the concentration of the nano silicon dioxide is 0.012g/mL;
(2) Mixing magnesium powder, the obtained precursor and sodium chloride, introducing a mixed gas of argon and hydrogen, heating at a speed of 7 ℃/min, heating to a reaction temperature of 700 ℃ for reduction reaction, and carrying out acid washing after the reaction is finished, wherein the washing liquid for acid washing is hydrochloric acid, so that the composite anode material is obtained.
Example 8
The present example provides a method for preparing a composite anode material, which is the same as example 1 except that the meta-diphenol in step (1) is replaced with graphite of equal mass.
Example 9
This example provides a method for preparing a composite negative electrode material, and the process steps are the same as example 1, except that the concentration of hexadecyl trimethyl ammonium bromide in step (1) is 0.02 g/mL.
Example 10
This example provides a method for preparing a composite negative electrode material, and the process steps are the same as example 1, except that the concentration of hexadecyl trimethyl ammonium bromide in step (1) is 0.05 g/mL.
Example 11
The present example provides a method for preparing a composite negative electrode material, and the other process steps are the same as those of example 1, except that the concentration of the nano silicon dioxide in the step (1) is 0.008 g/mL.
Example 12
The present example provides a method for preparing a composite anode material, and the other process steps are the same as those of example 1, except that the concentration of the nano silicon dioxide in the step (1) is 0.02 g/mL.
Example 13
The present example provides a method for preparing a composite anode material, and the other process steps are the same as those of example 1 except that the temperature rising rate in step (2) is 1 ℃/min.
Example 14
The present example provides a method for preparing a composite anode material, and the other process steps are the same as those of example 1 except that the temperature rising rate in step (2) is 12 ℃/min.
Comparative example 1
This comparative example provides a preparation method of a composite anode material, which is referred to CN106374088A, wherein the mass ratio of magnesium powder, silicon element and carbon element is the same as in example 1.
Comparative example 2
This comparative example provides a nano-silicon negative electrode material (CW-Si-001).
And assembling the composite anode material into a lithium ion battery according to the GB31241-2014 standard.
The testing method comprises the following steps: for the obtained lithium ion battery, the first coulombic efficiency is obtained by circulating 3 circles under the current density of 0.21A/g in the voltage interval of 3-0.01V. After 230 cycles at a current density of 0.84A/g, a reversible capacity is obtained. The results are shown in Table 1.
TABLE 1
| Test number | First coulombic efficiency (%) | Reversible circulation capacity (mAh/g) |
| Example 1 | 73.43 | 1239.3 |
| Example 2 | 70.24 | 989.5 |
| Example 3 | 70.45 | 993.8 |
| Example 4 | 71.35 | 1123.6 |
| Example 5 | 71.67 | 1146.3 |
| Example 6 | 68.48 | 943.5 |
| Example 7 | 67.68 | 923.6 |
| Example 8 | 64.54 | 823.6 |
| Example 9 | 70.24 | 971.3 |
| Example 10 | 70.38 | 967.7 |
| Example 11 | 72.34 | 843.5 |
| Example 12 | 69.71 | 924.6 |
| Example 13 | 67.67 | 911.6 |
| Example 14 | 68.83 | 921.5 |
| Comparative example 1 | 65.44 | 873.7 |
| Comparative example 2 | 72.4 | 232.3 |
From the data in table 1, the following conclusions can be drawn:
(1) As can be seen from examples 1-5, the invention simplifies the traditional two-step magnesia reduction process for preparing the carbon-coated nano-silicon anode material, realizes the preparation of the carbon-coated nano-silicon anode material through one-step magnesia reduction reaction, reduces the energy consumption, reduces the process flow and is easy for large-scale production. Meanwhile, the preparation method provided by the invention reduces the influence of volume expansion in the process of silicon lithium intercalation, and maintains the stability of the structure of the anode material. The conductive performance of the negative electrode is improved by coating the carbon material on the outermost layer, the impedance is reduced, the activity of the electrode material is improved, and the cycle performance of the material is improved; according to the composite anode material provided by the invention, silicon carbide is generated at the silicon-carbon interface, so that the structural stability of the composite anode material is further maintained.
(2) As can be seen from the comparison of examples 6 and 7 with example 1, when the particle size range of the nano silicon dioxide exceeds 200-500nm, the prepared composite anode material has low initial coulombic efficiency and low reversible cycle capacity, which indicates that the particle size range of the nano silicon dioxide provided by the invention is beneficial to preparing the composite anode material with structural stability and excellent electrochemical performance.
(3) From a comparison of example 8 and example 1, it is evident that when the carbon source is replaced with graphite, the prepared composite anode material has low initial coulombic efficiency and low reversible cycle capacity, which indicates that the carbon source provided by the invention is beneficial to preparing composite anode material with structural stability and excellent electrochemical performance.
(4) As can be seen from the comparison of examples 9 and 10 with example 1, when the concentration of hexadecyl trimethyl ammonium bromide exceeds 0.03-0.04g/mL, the prepared composite anode material has low initial coulombic efficiency and low reversible cycle capacity, which indicates that the concentration of the surfactant provided by the invention is beneficial to preparing the composite anode material with structural stability and excellent electrochemical performance.
(5) As can be seen from the comparison of examples 11 and 12 with example 1, when the concentration of the silicon dioxide exceeds 0.01-0.015g/mL, the prepared composite anode material has low initial coulombic efficiency and low reversible cycle capacity, which indicates that the concentration of the silicon dioxide provided by the invention is favorable for preparing the composite anode material with structural stability and excellent electrochemical performance.
(6) As can be seen from the comparison of examples 13 and 14 with example 1, when the temperature rising rate of the magnesium thermal reaction exceeds 2-10 ℃/min, the prepared composite anode material has low initial coulombic efficiency and low reversible cycle capacity, which indicates that the temperature rising rate of the magnesium thermal reaction provided by the invention is beneficial to preparing the composite anode material with structural stability and excellent electrochemical performance.
(7) As can be seen from the comparison between comparative example 1 and example 1, the preparation method provided by the present application has high initial coulombic efficiency and high reversible cycle capacity compared with the magnesium thermal method in the prior art, and the present application improves the preparation method of preparing carbon-coated nano silicon by the magnesium thermal method, so as to obtain the composite anode material with stable structure and excellent electrochemical performance.
(8) As can be seen from comparison of comparative example 2 and example 1, the preparation method provided by the application has high initial coulombic efficiency and high reversible cycle capacity compared with the silicon anode material in the prior art, and the preparation method for preparing carbon-coated nano silicon by using the magnesia-thermal method is improved, so that the composite anode material with stable structure and excellent electrochemical performance is obtained.
The applicant states that the process flow of the present invention is illustrated by the above examples, but the present invention is not limited to the above process flow, i.e. it does not mean that the present invention must be carried out in dependence on the above detailed process flow. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.
Claims (19)
1. The preparation method of the composite anode material is characterized by comprising the following steps of:
(1) Mixing a carbon source solution, a nano silicon dioxide solution and an aldehyde compound in a volume ratio of (9-12), wherein the concentration of the carbon source is 5-10mg/mL, the concentration of a hydrolysis catalyst in the carbon source solution is 2-3mg/mL, the concentration of the nano silicon dioxide is 0.01-0.015g/mL, and the mixing mode in the step (1) comprises ultrasonic dispersion and/or stirring; ultrasonic dispersing for 20-40min, and stirring at 30-50deg.C for 6-10 hr to obtain precursor;
the preparation method of the nano silicon dioxide comprises the following steps: mixing an organosilicon source solution and a hydrolysis catalyst solution, wherein the concentration of the organosilicon source is 0.02-0.04g/ml, the concentration of the hydrolysis catalyst is 0.3-0.4mg/ml, stirring for 4-6h at the rotating speed of 500-700r/min, centrifuging, washing and drying to obtain the nano silicon dioxide;
(2) 1 (9-11) magnesium powder, the obtained precursor and salt, introducing mixed gas with the flow of 0.02-0.05L/min, heating at 2-10 ℃/min, heating to the reaction temperature of 600-800 ℃ for reduction reaction, and pickling after the reaction is finished to obtain the composite anode material;
the carbon source comprises any one or a combination of at least two of m-diphenol, polyvinylpyrrolidone, o-diphenol, p-diphenol or a-phenol naphthalene; the particle size range of the nano silicon dioxide is 200-500nm; the organic silicon source comprises any one or a combination of at least two of tetraethoxysilane, diallyl phenyl dimethyl silane, triethoxysilane and methyltriallyl silane; the pickling solution comprises any one or a combination of at least two of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; the salt is NaCl and/or CaCl 2 。
2. The method of claim 1, wherein the carbon source solution of step (1) comprises a carbon source, a solvent, and a hydrolysis catalyst.
3. The method of claim 2, wherein the carbon source is m-diphenol.
4. The method of preparation according to claim 2, wherein the solvent comprises methanol and/or ethanol.
5. The method of preparation of claim 2, wherein the hydrolysis catalyst comprises aqueous ammonia.
6. The method of claim 1, wherein the silica solution of step (1) comprises water, a surfactant, and nanosilica.
7. The method of claim 6, wherein the surfactant comprises any one or a combination of at least two of cetyltrimethylammonium bromide, sodium stearate, and sodium dodecylbenzenesulfonate.
8. The method according to claim 6, wherein the concentration of the surfactant in the silica solution in the step (1) is 0.03 to 0.04g/mL.
9. The method of claim 1, wherein the solvent of the silicone source solution comprises an alcohol.
10. The method of claim 1, wherein the solvent of the hydrolysis catalyst solution comprises a hydroalcoholic mixture.
11. The method according to claim 10, wherein the volume ratio of water to alcohol in the aqueous-alcoholic mixture is (1.5-2): 1.
12. The method of claim 1, wherein the hydrolysis catalyst comprises aqueous ammonia.
13. The method of claim 1, wherein the means of mixing comprises stirring.
14. The method according to claim 1, wherein the aldehyde compound in step (1) is formaldehyde and/or acetaldehyde.
15. The method of claim 1, further comprising grinding between the mixing and the elevated temperature reduction of step (2).
16. The method according to claim 15, wherein the mixture is introduced during the temperature-increasing reduction in step (2).
17. The method of claim 16, wherein the mixture comprises at least two of hydrogen, argon, helium, or nitrogen.
18. A composite anode material, characterized in that it is obtained by the preparation method according to any one of claims 1 to 17.
19. A lithium ion battery comprising the composite anode material of claim 18.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106374088A (en) * | 2016-10-14 | 2017-02-01 | 浙江天能能源科技股份有限公司 | Method for preparing silicon/carbon composite material with magnesiothermic reduction process |
| CN109659486A (en) * | 2018-11-22 | 2019-04-19 | 中兴高能技术有限责任公司 | Preparation method, cathode and the lithium ion battery of negative electrode of lithium ion battery |
| CN109755482A (en) * | 2017-11-01 | 2019-05-14 | 同济大学 | Silicon/carbon composite and preparation method thereof |
| CN112028066A (en) * | 2020-08-27 | 2020-12-04 | 湖南宸宇富基新能源科技有限公司 | Silicon-carbon composite negative electrode material, and preparation method and application thereof |
| CN112054171A (en) * | 2020-08-13 | 2020-12-08 | 利普同呈(江苏)新能源科技有限公司 | Carbon-silicon negative electrode material and preparation method thereof |
| CN112349899A (en) * | 2019-09-26 | 2021-02-09 | 贝特瑞新材料集团股份有限公司 | Silicon-based composite negative electrode material, preparation method thereof and lithium ion battery |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106374088A (en) * | 2016-10-14 | 2017-02-01 | 浙江天能能源科技股份有限公司 | Method for preparing silicon/carbon composite material with magnesiothermic reduction process |
| CN109755482A (en) * | 2017-11-01 | 2019-05-14 | 同济大学 | Silicon/carbon composite and preparation method thereof |
| CN109659486A (en) * | 2018-11-22 | 2019-04-19 | 中兴高能技术有限责任公司 | Preparation method, cathode and the lithium ion battery of negative electrode of lithium ion battery |
| CN112349899A (en) * | 2019-09-26 | 2021-02-09 | 贝特瑞新材料集团股份有限公司 | Silicon-based composite negative electrode material, preparation method thereof and lithium ion battery |
| CN112054171A (en) * | 2020-08-13 | 2020-12-08 | 利普同呈(江苏)新能源科技有限公司 | Carbon-silicon negative electrode material and preparation method thereof |
| CN112028066A (en) * | 2020-08-27 | 2020-12-04 | 湖南宸宇富基新能源科技有限公司 | Silicon-carbon composite negative electrode material, and preparation method and application thereof |
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