CN115084532B - Negative electrode material, preparation method thereof, negative plate and lithium ion battery - Google Patents
Negative electrode material, preparation method thereof, negative plate and lithium ion battery Download PDFInfo
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- CN115084532B CN115084532B CN202211014147.7A CN202211014147A CN115084532B CN 115084532 B CN115084532 B CN 115084532B CN 202211014147 A CN202211014147 A CN 202211014147A CN 115084532 B CN115084532 B CN 115084532B
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- 239000007773 negative electrode material Substances 0.000 title claims abstract description 67
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 19
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 19
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
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- 229910052710 silicon Inorganic materials 0.000 claims abstract description 63
- 239000010703 silicon Substances 0.000 claims abstract description 63
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 42
- 239000004020 conductor Substances 0.000 claims abstract description 31
- 238000002156 mixing Methods 0.000 claims abstract description 30
- MKPXGEVFQSIKGE-UHFFFAOYSA-N [Mg].[Si] Chemical compound [Mg].[Si] MKPXGEVFQSIKGE-UHFFFAOYSA-N 0.000 claims abstract description 29
- 229910000861 Mg alloy Inorganic materials 0.000 claims abstract description 28
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000011856 silicon-based particle Substances 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims abstract description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000006004 Quartz sand Substances 0.000 claims abstract description 21
- 239000002243 precursor Substances 0.000 claims abstract description 19
- 238000000034 method Methods 0.000 claims abstract description 17
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- 238000001816 cooling Methods 0.000 claims abstract description 8
- 239000010410 layer Substances 0.000 claims description 228
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 37
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- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 9
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 9
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 9
- 239000011777 magnesium Substances 0.000 claims description 9
- 229910052749 magnesium Inorganic materials 0.000 claims description 9
- 238000000576 coating method Methods 0.000 claims description 7
- 239000011149 active material Substances 0.000 claims description 6
- 239000010405 anode material Substances 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 6
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 claims description 6
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 6
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 6
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 6
- 229910001947 lithium oxide Inorganic materials 0.000 claims description 6
- 239000011230 binding agent Substances 0.000 claims description 3
- 238000005056 compaction Methods 0.000 claims description 3
- 229910000103 lithium hydride Inorganic materials 0.000 claims description 3
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 claims description 3
- 239000011229 interlayer Substances 0.000 claims 1
- 239000013078 crystal Substances 0.000 abstract description 8
- 230000008569 process Effects 0.000 abstract description 8
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- 230000000052 comparative effect Effects 0.000 description 22
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- 230000008859 change Effects 0.000 description 17
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- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 5
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 5
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- GCICAPWZNUIIDV-UHFFFAOYSA-N lithium magnesium Chemical compound [Li].[Mg] GCICAPWZNUIIDV-UHFFFAOYSA-N 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 239000003607 modifier Substances 0.000 description 3
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- 239000001095 magnesium carbonate Substances 0.000 description 2
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 2
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 2
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- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 1
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- 229910020632 Co Mn Inorganic materials 0.000 description 1
- 229910020678 Co—Mn Inorganic materials 0.000 description 1
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- 229910018068 Li 2 O Inorganic materials 0.000 description 1
- AUBNQVSSTJZVMY-UHFFFAOYSA-M P(=O)([O-])(O)O.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.[Li+] Chemical compound P(=O)([O-])(O)O.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.C(C(=O)O)(=O)F.[Li+] AUBNQVSSTJZVMY-UHFFFAOYSA-M 0.000 description 1
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- 229920002125 Sokalan® Polymers 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- PFYQFCKUASLJLL-UHFFFAOYSA-N [Co].[Ni].[Li] Chemical compound [Co].[Ni].[Li] PFYQFCKUASLJLL-UHFFFAOYSA-N 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
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- 238000013461 design Methods 0.000 description 1
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- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
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- DEUISMFZZMAAOJ-UHFFFAOYSA-N lithium dihydrogen borate oxalic acid Chemical compound B([O-])(O)O.C(C(=O)O)(=O)O.C(C(=O)O)(=O)O.[Li+] DEUISMFZZMAAOJ-UHFFFAOYSA-N 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 description 1
- XKLXIRVJABJBLQ-UHFFFAOYSA-N lithium;2-(trifluoromethyl)-1h-imidazole-4,5-dicarbonitrile Chemical compound [Li].FC(F)(F)C1=NC(C#N)=C(C#N)N1 XKLXIRVJABJBLQ-UHFFFAOYSA-N 0.000 description 1
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- DVATZODUVBMYHN-UHFFFAOYSA-K lithium;iron(2+);manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[Fe+2].[O-]P([O-])([O-])=O DVATZODUVBMYHN-UHFFFAOYSA-K 0.000 description 1
- ILXAVRFGLBYNEJ-UHFFFAOYSA-K lithium;manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[O-]P([O-])([O-])=O ILXAVRFGLBYNEJ-UHFFFAOYSA-K 0.000 description 1
- MCVFFRWZNYZUIJ-UHFFFAOYSA-M lithium;trifluoromethanesulfonate Chemical compound [Li+].[O-]S(=O)(=O)C(F)(F)F MCVFFRWZNYZUIJ-UHFFFAOYSA-M 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
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- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/134—Electrodes based on metals, Si or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—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
- 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
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- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a preparation method of a negative electrode material, which comprises the following steps: uniformly mixing silicon-magnesium alloy particles, silicon particles and quartz sand particles, heating for the next time in vacuum, cooling and performing ball milling to obtain a magnesium-doped precursor; mixing the magnesium-doped precursor with a regulator, heating for the second time, cooling, and performing ball milling to obtain the cathode material; the mass ratio of the silicon-magnesium alloy particles to the silicon particles to the quartz sand particles is 2-30, 70-150, 2-100, the regulator is obtained by mixing a carbon source and a conductive material, and the mass ratio of the regulator to the magnesium-doped precursor is 1-30. The invention also discloses the negative electrode material prepared by the method, a negative electrode plate and a lithium ion battery. The negative electrode material provided by the invention can inhibit the volume expansion of silicon crystals, and reduces the gas generation in the pole piece processing and battery cycle processes while improving the first coulombic efficiency and the cycle stability of the battery.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, and particularly relates to a negative electrode material, a preparation method of the negative electrode material, a negative electrode sheet and a lithium ion battery.
Background
Currently, lithium Ion Batteries (LIBs) are widely used in portable devices and electronic products, however, there are still some problems in the application of electric vehicles and renewable energy storage power grids, including energy density, material cost, and safety in use. Therefore, the development of lithium ion batteries with high energy density and long cycle life performance is the mainstream direction of research and development at present.
Graphite remains the only negative electrode material that can be used in large commercial fields, although its capacity is only 372mAh/g, in contrast to silicon (Si), which is the negative electrode material, whose highest theoretical capacity reaches 4200mAh/g, and thus attracts countless people's attention. However, silicon anodes have several fatal drawbacks that limit their applications, such as large volume expansion, poor cycling performance capability, low first coulombic efficiency, etc. Through research on silicon-containing battery systems, li generated by reaction of lithium and silicon in the circulation process is discovered 4 SiO 4 、Li 2 O and Li 6 Si 2 O 7 The irreversible substances are the root causes of capacity reduction and low first effect; in addition, the strain caused by the anisotropy of different crystal planes during lithiation/delithiation directly leads to particle breakage, and when silicon particles are broken, a continuously generated SEI layer consumes limited cathode lithium ions, which is not beneficial to maintaining the stability of a Solid Electrolyte Interface (SEI), and finally leads to rapid reduction of coulombic efficiency and capacity. At present, the cycle performance and the first coulombic efficiency of the silicon negative electrode material obtained by doping lithium on the basis of carbon coating, compounding the silicon negative electrode material with graphite and the like are effectively improved. However, lithium reacts with water to generate gas, which results in poor processability and low yield of the negative electrode sheet and the battery.
Disclosure of Invention
The invention aims to solve the technical problem of providing a negative electrode material, wherein silicon particles are doped with a silicon-magnesium alloy for coating, and then the silicon particles or silica particles and a regulator are mixed and heated to generate a carbonized coating layer, so that the volume expansion of silicon crystals can be inhibited, the lithium-containing substance exposed on the surface layer of the negative electrode material is reduced, the gas generated by the reaction between the negative electrode material and water is further reduced, and the material has better electrochemical performance.
In order to solve the technical problems, the invention provides the following technical scheme:
in a first aspect, the present invention provides a method for preparing an anode material, comprising the steps of:
uniformly mixing silicon-magnesium alloy particles, silicon particles and quartz sand particles, heating the mixture in vacuum for the first time, and cooling and ball-milling the mixture to obtain a magnesium-doped precursor;
mixing the magnesium-doped precursor with a regulator, heating for the second time, cooling, and performing ball milling to obtain the negative electrode material;
the mass ratio of the silicon-magnesium alloy particles to the silicon particles to the quartz sand particles is (2) - (30) - (150).
Furthermore, the particle diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are all between 0.05 and 200 mu m.
Further, the regulator is obtained by mixing a carbon source and a conductive material according to a mass ratio of 80 to 100.
Further, the temperature of the primary heating is 800-1250 ℃, and the time is 1-5h; the temperature of the secondary heating is 400-950 ℃, and the time is 1-5h.
Further, the silicon-magnesium alloy particles contain 0.2 to 20wt% of lithium-containing substances;
the lithium-containing substance includes at least one of metallic lithium, lithium oxide, lithium hydroxide, lithium carbonate, lithium hydride, lithium nitride, lithium fluoride, lithium chloride, and lithium bromide.
In a second aspect, the invention provides an anode material prepared by the method.
Further, the pH value of the negative electrode material is 10.2-13.2, the lithium content is 0.5-12wt%, and the magnesium content is 0.01-5wt%.
In a third aspect, the invention provides a negative plate, which comprises a negative current collector and a negative layer formed on at least one side surface of the negative current collector;
the cathode layer sequentially comprises a bottom layer, a sandwich layer, a striation layer and a top layer, wherein the bottom layer and the sandwich layer are both silicon-containing layers, the silicon-containing layers contain the cathode material, and the silicon content in the bottom layer is lower than that of the sandwich layer; the cross grain layer and the top layer are silicon-free layers, and the silicon-free layers do not contain the negative electrode material.
Further, the bottom layer and the sandwich layer are composed of an active material, a binding material and a conductive material according to a mass ratio of 85 to 98 to 0.4 to 5.0.
Further, the median particle diameter D50-Si @ Mg & Li of the negative electrode material and the median particle diameter D50-Gr of the graphite active material satisfy the following relationship: 1-D50-Si @ Mg & Li/D50-Gr | is less than or equal to 3.2.
Further, the rib layer and the sandwich layer consist of a graphite active material, a bonding substance and a conductive material according to a mass ratio of 90 to 98 to 0.1 to 3.5.
Further, the compaction density of the negative electrode layer is 1.22 to 1.86g/cm 3 (ii) a The thickness of the negative electrode layer is less than or equal to 500 mu m.
Furthermore, the cross grain layer is composed of a plurality of lines which are formed on the sandwich layer and distributed at intervals; the spacing distance between two adjacent lines is more than or equal to 10 mu m.
Further, the cross-grain layer is obtained by coating the slurry on the sandwich layer by a corrugated scraper.
In a fourth aspect, the present invention provides a lithium ion battery, including a positive plate, a negative plate, a diaphragm and an electrolyte, where the diaphragm is configured to separate the positive plate from the negative plate, and the negative electrode is the above negative plate.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the cathode material provided by the invention, after magnesium lithium is doped and coated on the surface of the silicon particle, the silicon or silica particle and the regulator are mixed and heated to generate the carbonized coating layer, so that the volume expansion of silicon crystals can be inhibited, lithium-containing substances exposed on the surface layer of the cathode material are reduced, gas generated by reaction between the cathode material and water is reduced, and the material has better electrochemical performance.
2. According to the negative plate, the bottom layer, the sandwich layer, the cross grain layer and the top layer are arranged in a layered mode, when a battery is circulated, the high-silicon sandwich layer mainly exerts the high-capacity characteristic of a silicon material, and the low-silicon bottom layer bears the volume change stress of the single side of the high-silicon sandwich layer; the non-silicon top layer is coated on the upper layer of the high-silicon sandwich layer, the cross grain layer is embedded in the non-silicon top layer to form a beam, so that the beam bears the volume change stress of the other surface of the high-silicon sandwich layer, and on the premise of ensuring that the high capacity of a silicon negative electrode is exerted, the direct contact between the high-silicon sandwich layer and an electrolyte can be reduced as much as possible, the volume change of the silicon-containing layer and the reaction with the electrolyte are reduced, the gas production and the expansion rate of a pole piece in the processing and circulating processes of an electrode material can be effectively improved, and the structural performance of the negative pole piece is improved; in addition, the cross grain layer is equivalent to a reinforced structure in the top layer, bears the action of tensile stress of the top layer, and enhances the cracking resistance of the top layer.
Drawings
FIG. 1 is a schematic longitudinal sectional view of a negative electrode sheet of example 3;
FIG. 2 is a schematic cross-sectional view of a negative electrode sheet of example 3;
wherein: 1. a negative current collector sheet; 2. a surface negative electrode layer A; 21. a bottom layer; 22. a sandwich layer; 23. a cross grain layer; 24. a top layer.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The invention provides a preparation method of a negative electrode material, which comprises the following steps: (1) Uniformly mixing silicon-magnesium alloy particles, silicon particles and quartz sand particles, heating the mixture in vacuum for the first time, and cooling and ball-milling the mixture to obtain a magnesium-doped precursor; (2) And mixing the magnesium-doped precursor with a regulator, heating for the second time, cooling, and performing ball milling to obtain the cathode material.
In the invention, silicon magnesium alloy particles, silicon particles and quartz sand particles are mixed and heated in vacuum for one time, so that part of silicon can react with quartz sand (silicon dioxide) to obtain silicon monoxide, and a silicon magnesium layer can be formed on the surfaces of the silicon particles or the silicon dioxide. Wherein the temperature of the primary heating is preferably 800 to 1250 ℃, and may be, for example, 800 ℃, 820 ℃, 850 ℃, 880 ℃, 900 ℃, 920 ℃, 950 ℃, 980 ℃, 1000 ℃, 1020 ℃, 1050 ℃, 1080 ℃, 1100 ℃, 1120 ℃, 1150 ℃, 1180 ℃, 1200 ℃, 1220 ℃, 1250 ℃, etc.; the time for the primary heating is preferably 1 to 5 hours, and may be, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or the like.
In the invention, the particle diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are preferably 0.05 to 200 μm, and can be, for example, 1 to 100 μm, 5 to 100 μm, 1 to 50 μm, 5 to 50 μm, 1 to 40 μm, 5 to 40 μm, 1 to 30 μm, 5 to 30 μm and the like.
In the invention, the mass ratio of the silicon-magnesium alloy particles to the silicon particles to the quartz sand particles is preferably 2 to 30:70 to 150: the ratio of (2) - (100) is, for example, 15.
In the invention, the regulator is obtained by mixing a carbon source and a conductive material. Preferably, the regulator is prepared by mixing a carbon source and a conductive material according to a weight ratio of 80-100: a mass ratio of 0.1 to 24, for example, a mass ratio of 100. The carbon source can be selected from carbon source materials commonly used in the art, including but not limited to one or more of asphalt, dopamine, polypropylene, polyethylene, polyaniline, polyvinyl alcohol, and polyamide. The conductive material can be selected from conductive materials commonly used in the art, including but not limited to one or more of conductive carbon black, acetylene black, graphite, graphene, micro-nano linear conductive materials and micro-nano tubular conductive materials.
In the invention, the regulator can be adhered to the surface of the magnesium-doped precursor after being mixed with the magnesium-doped precursor, and a carbonized coating layer is formed after secondary heating, so that the volume expansion of silicon crystals can be inhibited; meanwhile, the silicon crystal is isolated from the electrolyte by the carbonized coating layer, so that the exposure of lithium-containing substances on the surface layer of the negative electrode material is reduced, the gas generated by the reaction of the negative electrode material and water is reduced, and the material has better electrochemical performance. The mass ratio of the modifier to the magnesium-doped precursor is preferably 1 to 30:100, and can be, for example, 1. If the content of the modifier is too low, a complete carbonized coating layer cannot be formed on the surface of the magnesium-doped precursor, and if the content of the modifier is too high, the formed carbonized coating layer is too thick, which affects the capacity of the battery.
In the present invention, the temperature of the secondary heating is preferably 400 to 950 ℃, and may be, for example, 400 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ or the like; the time for the secondary heating is preferably 1 to 5 hours, and may be, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or the like.
In a preferred embodiment, the silicon-magnesium alloy particles further contain a certain content of lithium-containing substances. The addition of the lithium-containing substance can reduce the expansion of silicon crystals, and simultaneously can improve the first effect of the lithium battery and the electrochemical performance of the lithium battery. The content of the lithium-containing substance is preferably 0.2 to 20wt%, and may be, for example, 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4wt%, 4.5wt%, 5wt%, 10 wt%, 15 wt%, 20wt%, or the like. The lithium-containing substance may be one or more of metallic lithium, lithium oxide, lithium hydroxide, lithium carbonate, lithium hydride, lithium nitride, lithium fluoride, lithium chloride, and lithium bromide.
The invention also provides the anode material prepared by the method. Preferably, the median diameter D50 of the anode material is 1.5 to 24 mu m, and the specific surface area SSA is 0.40 to 2.6m 2 /g。
Preferably, the negative electrode material contains 0.5 to 12wt% of lithium, 0.01 to 5wt% of magnesium, and the pH value of the negative electrode material is 10.2 to 13.2. The pH test method comprises the following steps: mixing and stirring the negative electrode material and boiled and cooled deionized water according to a mass ratio of 1.
The negative electrode material reacts with water in the air and carbon dioxide to generate a basic substance such as lithium hydroxide, lithium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, and the like, and the pH of the surface of the negative electrode material is determined by the amount of the basic substance generated by the reaction. The amount of lithium oxide and magnesium oxide on the surface of the negative electrode material can be controlled by adjusting the addition amount of lithium and magnesium, and further the pH value of the surface of the negative electrode material is controlled. When the amount of lithium and magnesium is excessive, the excessive lithium oxide and magnesium oxide on the surface can react with water in the air and carbon dioxide to generate excessive alkaline substances such as lithium hydroxide, lithium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate and the like, so that the pH value of the surface of the negative electrode material is high, the alkaline substances can be decomposed in the charging process and react with electrolyte to generate gas, the diffusion of lithium ions in the charging and discharging process is hindered, and the electrochemical performance of the material is reduced; when the amount of lithium and magnesium mixed in the negative electrode material is too small or zero, the effect of lithium and magnesium for improving the performance of the negative electrode material cannot be exerted, and at the moment, only very little lithium oxide and magnesium oxide react with water and carbon dioxide to generate alkaline substances on the surface of the negative electrode material, so the pH value of the surface of the negative electrode material is low. In the invention, the pH range of the surface of the negative electrode material is controlled to be 10.2-13.2 through reasonable addition amounts of lithium and magnesium (the lithium content is 0.5-12wt% and the magnesium content is 0.01-5wt%), so that the effect of improving the performance of the negative electrode material can be achieved.
The invention also provides a negative plate, which comprises a negative current collector and a negative layer on the surface A or/and the surface B on the negative current collector, wherein the structures of the negative layer on the surface A and the negative layer on the surface B are symmetrical structures, and the negative layer on the surface A is explained in detail below.
In the invention, the negative current collector can be made of a negative current collector material commonly used in the field, including but not limited to one or more of copper foil, foamed nickel/copper foil, zinc-plated copper foil, nickel-plated copper foil, carbon-coated copper foil, nickel foil, titanium foil and carbon-containing porous copper foil; preferably a copper foil, a zinc-plated copper foil, a nickel-plated copper foil or a carbon-coated copper foil.
Referring to fig. 1-2, in the invention, the negative electrode layer includes a bottom layer, a sandwich layer, a striation layer and a top layer, which are sequentially stacked on the negative electrode current collector, the four layers are closely arranged, and the compaction density of the four layers is preferably 1.22 to 1.86g/cm 3 In between. Preferably, the total thickness D1+ D2+ D3+ D4 of the four layers is less than or equal to 500 μm, taking the thickness of the bottom layer as D1, the thickness of the sandwich layer as D2, the thickness of the striation layer as D3 and the thickness of the top layer as D4.
In the invention, the striation layer is composed of a plurality of lines which are formed on the sandwich layer and distributed at intervals, therefore, the striation layer is attached to the upper layer surface of the sandwich layer, and the interval lines of the striation layer are filled with the top layer, so that the striation layer contacts the upper layer surface of the sandwich layer, and the top layer between the lines of the striation layer also contacts the upper layer surface of the sandwich layer. According to the invention, the cross grain layer is arranged in the negative plate, so that the function of a beam is achieved, the internal structure of the top layer can be strengthened, the tensile stress of the top layer is borne, and the anti-cracking performance of the top layer is enhanced. Preferably, lines in the cross-grain layer are parallel to the edge of the negative electrode current collector sheet, and the spacing distance between every two adjacent lines is larger than or equal to 10 micrometers.
In the invention, the cross grain layer can be obtained by coating the slurry on the sandwich layer by adopting a corrugated scraper, and the corrugated scraper coats the slurry into lines at intervals. By controlling the structure of the wavy scraper, the parameters such as the size, the distance and the like of lines in the transverse line layer can be adjusted.
In the invention, the bottom layer, the sandwich layer, the striation layer and the top layer are made of different materials, wherein the bottom layer is a low silicon layer, the sandwich layer is a high silicon layer, and the striation layer and the top layer are both silicon-free layers. The conception of the structure design is as follows: the high-silicon sandwich layer mainly plays the high-capacity characteristic of the silicon material, and the lower-silicon bottom layer on the lower side can bear the volume change stress on one side of the high-silicon sandwich layer to inhibit the volume expansion of the silicon crystal; the silicon-free top layer is coated on the upper layer of the high-silicon sandwich layer, so that the volume change stress on the other surface of the high-silicon sandwich layer can be borne, the direct contact between the high-silicon sandwich layer and electrolyte can be reduced, and the reaction between the silicon-containing layer and the electrolyte can be reduced. Therefore, the arrangement of the low-silicon bottom layer and the silicon-free top layer can effectively improve the gas production and the expansion rate of the pole piece in the processing and circulating processes of the electrode material and improve the structural performance of the negative pole piece on the premise of ensuring that the high capacity of the silicon negative pole is fully exerted. In addition, the cross grain layer is embedded in the silicon-free top layer to form a cross beam, so that the cracking resistance of the top layer can be enhanced, the expansion stress of the high-silicon sandwich layer can be better borne, and the expansion of the pole piece is inhibited.
In the invention, the cathode material is added to the raw materials of the bottom layer and the sandwich layer, and the cathode material is not added to the cross grain layer and the top layer. In a preferred embodiment, the raw materials of the bottom layer and the sandwich layer comprise a preganganese-graphite active material, a binder and a conductive material according to a mass ratio of 85 to 98, which is as follows, of 0.2 to 5.0.
The "pre-magnesiated-graphite active material" refers to an active material obtained by mixing a negative electrode material with a graphite active material, wherein the graphite active material includes, but is not limited to, one or more of artificial graphite, natural graphite and modified graphite.
The above binding substance can be selected from binders commonly used in the art, including but not limited to one or more of polyacrylonitrile, polyvinylidene fluoride, polyvinyl alcohol, sodium carboxymethylcellulose, polymethacrylic acid, polyacrylic acid, lithium polyacrylate, polyacrylamide, polyamide, polyimide, polyacrylate, styrene butadiene rubber, sodium alginate, chitosan, polyethylene glycol, guar gum, etc.
The conductive material can be selected from conductive agents commonly used in the art, including but not limited to one or more of conductive carbon black, carbon nanotubes and graphene.
Because the silicon content of the bottom layer and the sandwich layer is different, the proportion of the negative electrode material and the graphite active material in the pre-magnesium-graphite active material in the bottom layer and the sandwich layer is different. For the low-silicon bottom layer, the negative electrode material and the graphite active material in the premagnesized-graphite active material are mixed according to a mass ratio of 5 to 20 to 100, for example, the mass ratio can be from 5. For the high-silicon sandwich layer, the anode material and the graphite active material in the premagnesized-graphite active material are mixed according to a mass ratio of 20 to 60 to 40 to 100, wherein the mass ratio can be, for example, from the following formula.
Preferably, when D50-Si @ Mg & Li represents the median particle diameter of the negative electrode material and D50-Gr represents the median particle diameter of the graphite active material, D50-Si @ Mg & Li and D50-Gr satisfy the following relationship: 1-D50-Si @ Mg & Li/D50-Gr | is less than or equal to 3.2.
In the negative electrode active material, the particle diameter of the negative electrode active material, whether it is a negative electrode material or a graphite active material, has an important influence on the performance of the battery. On one hand, the specific surface area is continuously increased along with the reduction of the particle size of the particles, and the side reaction on the surface of the negative active material is increased along with the increase of the specific surface area, so that the charge and discharge performance of the battery is reduced, and the cycle performance is deteriorated; on the other hand, as the particle diameter of the particles increases, the specific surface area decreases, and the contact site of the negative electrode active material with the electrolyte decreases, thus being disadvantageous to the migration, diffusion, and electron transport of lithium ions, and increasing the interface resistance. In the invention, in consideration of the influence of the particle size, the particle size ratio of the negative electrode material and the graphite active material particles is designed to meet the condition that the ratio of |1-D50-Si @ Mg & Li/D50-Gr | is less than or equal to 3.2, so that the lithium ion migration, diffusion and electron transportation adaptability between the negative electrode material and the graphite active material particles is better, and the problem of poor material performance caused by larger particle size difference can be avoided.
In the invention, the negative electrode layer can be prepared by a layered coating method. Specifically, the negative electrode layer can be prepared by the following method:
mixing materials required by the bottom layer, the sandwich layer, the cross grain layer and the top layer, adding deionized water, stirring and adjusting the viscosity to obtain slurry of each layer; then through the straight line scraper with bottom extrusion coating on the negative pole mass flow body thin slice, after that through the straight line scraper with sandwich layer extrusion coating on the bottom, rethread raised grain scraper with the striation layer extrusion coating on sandwich layer, at last through the straight line scraper with top layer extrusion coating again on the striation layer, after drying, preforming, obtain the negative pole layer promptly on the negative pole mass flow body thin slice.
The negative plate can be applied to lithium ion batteries, can effectively reduce the battery capacity attenuation, and improves the cycle stability. The preparation method of the battery can be as follows: and (3) winding the negative plate, the diaphragm and the positive plate to obtain a battery cell, filling the battery cell into a battery case, drying in vacuum, injecting an electrolyte into the battery case, and packaging, standing, forming and grading to obtain the lithium ion battery.
The active material in the positive plate may be a common positive electrode material, including but not limited to one or more of lithium cobaltate, lithium nickelate, lithium manganate, lithium nickel cobalt aluminate, lithium manganese phosphate, lithium manganese iron phosphate, and lithium iron phosphate.
The diaphragm can be selected from one or more of diaphragm materials commonly used for lithium ion batteries, including but not limited to polypropylene diaphragms, polyethylene diaphragms, polyimide diaphragms and cellulose non-woven fabric diaphragms.
The electrolyte can be selected from the electrolyte commonly used in lithium ion batteries, and the electrolyte can contain one or more of lithium hexafluorophosphate, lithium bis-fluorosulfonylimide, lithium bis-trifluoromethylsulfonyl imide, lithium tetrafluoroborate, lithium dioxalate borate, lithium trifluoromethanesulfonate, lithium oxalyldifluoroborate, lithium difluorophosphate, 4, 5-dicyano-2-trifluoromethylimidazole lithium, lithium difluorodioxalate and lithium tetrafluorooxalate phosphate.
The present invention is further described below with reference to specific examples so that those skilled in the art can better understand the present invention and can practice the present invention, but the examples are not intended to limit the present invention.
The experimental procedures used in the following examples are conventional ones unless otherwise specified, and the materials, reagents and the like used therein are commercially available.
Example 1
1. Preparation of negative electrode material
Uniformly mixing silicon-magnesium alloy particles, silicon particles and quartz sand particles according to the mass ratio of 15. And then, mixing the precursor and the regulator according to the mass ratio of 100. The particle sizes of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are between 3 and 22 mu m, the silicon-magnesium alloy particles contain 3.4wt% of lithium carbonate, and the regulator is prepared by mixing asphalt and acetylene black according to a mass ratio of 100.
2. Preparation of cathode layer
(1) Preparing a bottom layer slurry
Mixing the pre-magnesium-graphite active material, the bonding substance and the conductive material according to a mass ratio of 92.5. The premagnesization-graphite active material is obtained by mixing a negative electrode material and artificial graphite according to a mass ratio of 10.
(2) Preparing sandwich layer slurry
Mixing the premagnesized-graphite active material, the bonding substance and the conductive material according to a mass ratio of 95.5. The premagnesization-graphite active material is obtained by mixing a negative electrode material and artificial graphite according to a mass ratio of 25 to 100, the binding substance is obtained by mixing styrene butadiene rubber and polyacrylamide according to a mass ratio of 5.
(3) Preparing sizing agent for the cross grain layer and the top layer
Mixing artificial graphite, a bonding substance and a conductive material according to a mass ratio of 97. The binding material is obtained by mixing styrene butadiene rubber and polyacrylamide according to a mass ratio of 5.
(4) Preparation of cathode layer
And adding deionized water into the prepared various slurries, stirring and adjusting the viscosity to obtain each layer of slurry, then coating each layer of slurry on a negative current collector nickel-plated copper foil sheet by using a linear scraper and a wavy scraper according to the sequence of a bottom layer, a sandwich layer, a cross grain layer and a top layer, drying and tabletting to obtain an A-side negative electrode layer with the thickness of 175 mu m on the negative current collector sheet.
And preparing the negative electrode layer on the B surface according to the same preparation method of the negative electrode layer on the A surface to obtain the negative electrode plate. (the median particle diameter D50-Si @ Mg & Li of the negative electrode material is 13.4 μm, the median particle diameter D50-Gr of the artificial graphite is 17.6 μm, |1-D50-Si @ Mg & Li/D50-Gr | =0.24 ≦ 3.2)
3. Preparation of lithium ion battery
Negative plate, isolating film and positive plate (containing 96.5% LiNi-Co-Mn oxide LiNi) 0.8 Co 0.12 Mn 0.08 O 2 Positive electrode active material) to obtain a battery core, filling the battery core into a battery shell, vacuum-drying, injecting electrolyte into the battery shell, and carrying out packaging, standing, formation and capacity grading to obtain the lithium ion battery.
Example 2
Example 2 differs from example 1 in that:
the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the low silicon layer slurry is 90.5; the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the high-silicon sandwich layer slurry is (95.5); the mass ratio of the artificial graphite, the bonding substance and the conductive material in the non-silicon transverse grain layer and the top layer slurry is 96.5.
Example 3
Example 3 differs from example 1 in that:
in the preparation process of the cathode material, the mass ratio of the silicon-magnesium alloy particles to the silicon particles to the quartz sand particles is 20; the temperature of the secondary heating is 550 ℃, and the heating time is 2.5h. The particle diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are between 5 and 31 mu m, and the silicon-magnesium alloy particles contain 3.8wt% of lithium carbonate.
Example 4
Example 4 differs from example 3 in that:
the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the low silicon layer slurry is 90.5; the mass ratio of the premagnesized-graphite active material, the bonding substance and the conductive material in the high-silicon sandwich layer slurry is 95.5; the mass ratio of the artificial graphite, the bonding substance and the conductive material in the non-silicon transverse grain layer and the top layer slurry is 96.5.
The thickness of the negative electrode layer was 189 μm, and the positive electrode active material was LiNi containing 96.2% of lithium nickel cobalt manganese oxide 0.6 Co 0.24 Mn 0.16 O 2 。
Example 5
Example 5 differs from example 1 in that:
in the preparation process of the cathode material, the mass ratio of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles is 25; the temperature of the secondary heating is 510 ℃, and the heating time is 3h. The grain diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are between 1 and 36 mu m, and the silicon-magnesium alloy particles contain 4.0wt% of lithium carbonate.
The thickness of the negative electrode layer was 189 μm, and the positive electrode active material was LiNi containing 96.2% of lithium nickel cobalt manganese oxide 0.6 Co 0.24 Mn 0.16 O 2 . Median particle diameter D50-Si @ Mg of negative electrode material&Li was 9.1 μm, and the median particle diameter D50-Gr of the artificial graphite was 19.4. Mu.m.
Example 6
Example 6 differs from example 5 in that:
the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the low silicon layer slurry is (90) to (5.5); the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the high-silicon sandwich layer slurry is (95.5); the mass ratio of the artificial graphite, the bonding substance and the conductive material in the slurry of the non-silicon transverse grain layer and the top layer is (96) as follows.
The thickness of the negative electrode layer was 143 μm.
Example 7
Example 7 differs from example 5 in that:
in the preparation process of the cathode material, the mass ratio of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles is 30; the temperature of the secondary heating is 450 ℃, and the heating time is 4h. The particle diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are between 2 and 38 mu m, and the silicon-magnesium alloy particles contain 4.5wt% of lithium carbonate.
The thickness of the negative electrode layer was 143 μm.
Example 8
Example 8 differs from example 7 in that:
the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the low silicon layer slurry is 90.5; the mass ratio of the premagnesization-graphite active material, the bonding substance and the conductive material in the high-silicon sandwich layer slurry is (95.5); the mass ratio of the artificial graphite, the bonding substance and the conductive material in the non-silicon transverse grain layer and the top layer slurry is 96.5.
The thickness of the negative electrode layer was 112 μm.
Comparative example 1
Comparative example 1 differs from example 1 in that: the precursor is not added with a regulator.
Comparative example 2
Comparative example 2 differs from example 1 in that: the negative current collector copper foil and the A-surface negative layer and the B-surface negative layer on the copper foil are not provided with silicon-free cross-grain layers.
Comparative example 3
Comparative example 3 differs from example 1 in that: the negative current collector copper foil and the A-surface negative layer and the B-surface negative layer on the copper foil are not provided with silicon-free top layers.
Comparative example 4
Comparative example 4 differs from example 6 in that: the precursor was not modified.
Comparative example 5
Comparative example 5 differs from example 6 in that: the negative current collector copper foil and the A-surface negative layer and the B-surface negative layer on the copper foil are not provided with silicon-free cross-grain layers.
Comparative example 6
Comparative example 6 differs from example 6 in that: the negative current collector copper foil and the A-surface negative layer and the B-surface negative layer on the copper foil are not provided with silicon-free top layers.
Test example
1. Expansion condition of battery pole piece under full charge, negative electrode material and gas production condition of battery
(1) Battery pole piece swelling at full charge
The thickness of the negative electrode plate after the pressing of the example and the comparative example and the thickness of the negative electrode plate of the battery under full charge are respectively measured, and the expansion rate of the negative electrode plate is calculated. Wherein, the expansion rate of the negative pole piece = (the thickness of the negative pole piece under full charge-the thickness of the negative pole piece after tabletting)/the thickness of the negative pole piece after tabletting = 100%.
(2) Gas generation of negative electrode material
Mixing 10g of the negative electrode material and 10g of boiled and cooled deionized water, loading the mixture into an aluminum-plastic film, sealing, placing the aluminum-plastic film into a water tank, measuring the volume by using a drainage method, standing for 24 hours, placing the aluminum-plastic film into the water tank again, measuring the volume by using the drainage method, and calculating the volume change rate before and after calculation, namely the gas production condition of the negative electrode material. Wherein, the volume change rate = (the sealed volume of the aluminum-plastic film after standing for 24 h-the volume of the aluminum-plastic film when sealing is finished)/the volume of the aluminum-plastic film when sealing is finished, = 100%.
(3) Gas generation condition of battery
And measuring the volume of the battery without the electrical property test and the volume of the battery in a full charge state after the charge-discharge cycle is 400 circles by using a drainage method, and calculating the volume change rate before and after the volume change rate, namely the gas production condition of the battery. Wherein, the volume change rate = (full charge cell volume-battery volume to be tested over 400 cycles)/battery volume to be tested × 100%.
2. Electrical property detection
The initial and cut-off voltages were 2.8V and 4.25V, respectively, at 25 ℃ at room temperature, and the batteries prepared in examples and comparative examples were charged from 1C to 4.25V, then charged at a constant voltage of 4.25V until the current was reduced to 0.05C, and discharged at 0.2C to 2.8V, and the capacity retention rates at the 50 th, 200 th and 400 th cycles were recorded.
TABLE 1 gas evolution of Pole pieces and batteries
From the results shown in table 1, the negative electrode sheet expansion ratios of comparative examples 1 to 6 were 46.5%, 39.8%, 41.7%, 46.8%, 41.3% and 43.7%, respectively, while the negative electrode sheet expansion ratios of examples 1 to 8 were 34.1 to 35.6%, and the negative electrode sheet expansion ratios of examples 1 to 8 were low as a whole. Compared with the test results of examples 1 to 8, when no regulator is added in comparative examples 1 and 4, the expansion rate of the negative pole piece is higher, and the effect is worse; and when the negative electrode does not have the cross grain layer and the top layer, the expansion rate of the negative electrode pole piece is also increased. From the volume change condition of the negative electrode material and the volume change condition of the battery after the 400 th circle of the battery cycle, when no regulator is added in the comparative examples 1 and 4, the volume change of the negative electrode material and the volume change of the battery after the 400 th circle of the battery cycle are larger, the gas production rate is more, the material processing and the battery cycle are not facilitated, and the gas production phenomenon is serious. In addition, the volume change of the batteries of comparative examples 3 and 6 is larger than that of the batteries of examples 1 to 8, and the gas production is high, which also shows that the battery has low structural performance and serious gas production phenomenon under the condition that no silicon-free top layer exists on the pole piece.
Therefore, by adding the regulator in the magnesium-lithium doped precursor and designing four layers with different silicon contents, namely the bottom layer, the sandwich layer, the cross grain layer and the top layer, on the premise that the high capacity of the silicon negative electrode is fully exerted, the direct contact between the high-silicon sandwich layer and the electrolyte is reduced as much as possible, the volume change of the silicon-containing layer and the reaction with the electrolyte are reduced, the gas production and the expansion rate of the pole piece in the processing process and the circulating process of the electrode material can be effectively improved, and the structural performance of the negative pole piece is improved.
TABLE 2 Capacity Retention at 25 ℃ for each battery group
As can be seen from Table 2, the capacity retention rates at 50 cycles of examples 1 to 8 are 88.3 to 90.7%, the capacity retention rates at 50 cycles of comparative examples 1 to 6 are 87.3 to 89.6%, and the capacity retention rates are not greatly different. However, from the 200 th circle and the 400 th circle, the batteries of comparative examples 3 and 6 are fast in attenuation, the battery capacity retention rate of comparative example 3 is respectively reduced to 83.1% and 80.6%, and the battery capacity retention rate of comparative example 6 is respectively reduced to 84.2% and 79.6%, which indicates that the battery is fast in attenuation under the condition that the pole piece is not provided with the silicon-free top layer. In the embodiments 1 to 8, the capacity retention rates are respectively between 87.2 to 89.7% and 85.2 to 86.6% in the 200 th circle and the 400 th circle, which indicates that the capacity attenuation can be effectively reduced and the cycling stability can be improved by adding the regulator in the magnesium-lithium doped precursor and designing four layers with different silicon contents, namely the bottom layer, the sandwich layer, the cross grain layer and the top layer.
The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.
Claims (12)
1. The preparation method of the anode material is characterized by comprising the following steps of:
uniformly mixing silicon-magnesium alloy particles, silicon particles and quartz sand particles, heating for the next time in vacuum, cooling and performing ball milling to obtain a magnesium-doped precursor;
mixing the magnesium-doped precursor with a regulator, heating for the second time, cooling, and performing ball milling to obtain the negative electrode material;
the mass ratio of the silicon-magnesium alloy particles to the silicon particles to the quartz sand particles is 2-30 to 70-150 to 2-100, the regulator is obtained by mixing a carbon source and a conductive material, and the mass ratio of the regulator to the magnesium-doped precursor is 1-30: 100; the temperature of the primary heating is 800-1250 ℃, and the time is 1-5h; the silicon-magnesium alloy particles contain 0.2 to 20wt% of lithium-containing substances; the lithium-containing substance includes at least one of metallic lithium, lithium oxide, lithium hydroxide, lithium carbonate, lithium hydride, lithium nitride, lithium fluoride, lithium chloride, and lithium bromide.
2. The preparation method of the negative electrode material as claimed in claim 1, wherein the particle diameters of the silicon-magnesium alloy particles, the silicon particles and the quartz sand particles are all between 0.05 and 200 μm.
3. The preparation method of the negative electrode material as claimed in claim 1, wherein the regulator is obtained by mixing a carbon source and a conductive material in a mass ratio of 80 to 100:0.1 to 24.
4. The preparation method of the negative electrode material as claimed in claim 1, wherein the temperature of the secondary heating is 400 ℃ to 950 ℃ and the time is 1 to 5 hours.
5. A negative electrode material produced by the method according to any one of claims 1 to 4.
6. The negative electrode material as claimed in claim 5, wherein the pH of the negative electrode material is 10.2 to 13.2, the lithium content is 0.5 to 12wt%, and the magnesium content is 0.01 to 5wt%.
7. The negative plate is characterized by comprising a negative current collector and a negative layer formed on at least one side surface of the negative current collector;
the cathode layer sequentially comprises a bottom layer, a sandwich layer, a striation layer and a top layer, wherein the bottom layer and the sandwich layer are both silicon-containing layers, the silicon-containing layers comprise the cathode material of claim 5, and the silicon content in the bottom layer is lower than that in the sandwich layer; the cross grain layer consists of a plurality of lines which are formed on the sandwich layer and distributed at intervals; the spacing distance between two adjacent lines is more than or equal to 10 mu m; the oversleeve layer and the top layer consist of a graphite active material, a bonding substance and a conductive material according to a mass ratio of 90-98.
8. The negative plate as claimed in claim 7, wherein the bottom layer and the interlayer are composed of an active material, a binder and a conductive material according to a mass ratio of 85 to 98, namely, 0.2 to 5.0; the active material of the bottom layer is obtained by mixing a negative electrode material and a graphite active material according to a mass ratio of 5-20 to 80-100, and the active material of the sandwich layer is obtained by mixing the negative electrode material and the graphite active material according to a mass ratio of 20-60 to 40-100.
9. The negative electrode sheet according to claim 8, wherein the negative electrode material has a median particle diameter D50-Si @ Mg & Li, and the graphite active material has a median particle diameter D50-Gr satisfying the following relationship: I1-D50-Si @ Mg & Li/D50-Gr I is less than or equal to 3.2.
10. The negative electrode sheet according to claim 7, wherein the compaction density of the negative electrode layer is 1.22 to 1.86g/cm 3 (ii) a The thickness of the negative electrode layer is less than or equal to 500 mu m.
11. The negative electrode sheet according to claim 7, wherein the cross-grain layer is obtained by coating the slurry on the sandwich layer with a corrugated doctor blade.
12. A lithium ion battery comprising a positive plate, a negative plate, a separator and an electrolyte, the separator being arranged to isolate the positive plate from the negative plate, wherein the negative plate is according to any one of claims 7 to 11.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674325A (en) * | 2004-03-26 | 2005-09-28 | 信越化学工业株式会社 | Silicon composite particles, preparation thereof, and negative electrode material for non-aqueous electrolyte secondary cell |
| CN105336934A (en) * | 2015-11-21 | 2016-02-17 | 中国计量学院 | Preparation method of silicon electrode composite material |
| CN110556529A (en) * | 2019-10-15 | 2019-12-10 | 溧阳天目先导电池材料科技有限公司 | Cathode composite material with multilayer core-shell structure and preparation method and application thereof |
| CN111072038A (en) * | 2019-12-27 | 2020-04-28 | 江西壹金新能源科技有限公司 | Modified silicon monoxide material for lithium ion battery cathode and preparation method thereof |
| CN111418095A (en) * | 2017-12-01 | 2020-07-14 | 大洲电子材料株式会社 | Negative active material for non-aqueous electrolyte secondary battery comprising silicon oxide composite and method for preparing same |
| CN112421018A (en) * | 2020-11-30 | 2021-02-26 | 成都新柯力化工科技有限公司 | Lithium battery porous silicon-oxygen-carbon negative electrode material for inhibiting volume expansion and preparation method thereof |
-
2022
- 2022-08-23 CN CN202211014147.7A patent/CN115084532B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674325A (en) * | 2004-03-26 | 2005-09-28 | 信越化学工业株式会社 | Silicon composite particles, preparation thereof, and negative electrode material for non-aqueous electrolyte secondary cell |
| CN105336934A (en) * | 2015-11-21 | 2016-02-17 | 中国计量学院 | Preparation method of silicon electrode composite material |
| CN111418095A (en) * | 2017-12-01 | 2020-07-14 | 大洲电子材料株式会社 | Negative active material for non-aqueous electrolyte secondary battery comprising silicon oxide composite and method for preparing same |
| CN110556529A (en) * | 2019-10-15 | 2019-12-10 | 溧阳天目先导电池材料科技有限公司 | Cathode composite material with multilayer core-shell structure and preparation method and application thereof |
| CN111072038A (en) * | 2019-12-27 | 2020-04-28 | 江西壹金新能源科技有限公司 | Modified silicon monoxide material for lithium ion battery cathode and preparation method thereof |
| CN112421018A (en) * | 2020-11-30 | 2021-02-26 | 成都新柯力化工科技有限公司 | Lithium battery porous silicon-oxygen-carbon negative electrode material for inhibiting volume expansion and preparation method thereof |
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