CN117012966A - Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof - Google Patents
Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof Download PDFInfo
- Publication number
- CN117012966A CN117012966A CN202310911176.1A CN202310911176A CN117012966A CN 117012966 A CN117012966 A CN 117012966A CN 202310911176 A CN202310911176 A CN 202310911176A CN 117012966 A CN117012966 A CN 117012966A
- Authority
- CN
- China
- Prior art keywords
- silicon
- oxygen
- carbon
- negative electrode
- mesophase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 59
- ADKPKEZZYOUGBZ-UHFFFAOYSA-N [C].[O].[Si] Chemical compound [C].[O].[Si] ADKPKEZZYOUGBZ-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 238000002360 preparation method Methods 0.000 title abstract description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 193
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 180
- 239000004005 microsphere Substances 0.000 claims abstract description 125
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 claims abstract description 100
- 239000007773 negative electrode material Substances 0.000 claims abstract description 74
- 239000010405 anode material Substances 0.000 claims abstract description 68
- 238000000034 method Methods 0.000 claims abstract description 36
- 239000011325 microbead Substances 0.000 claims abstract description 15
- 239000011258 core-shell material Substances 0.000 claims abstract description 14
- 239000011148 porous material Substances 0.000 claims description 19
- 239000002245 particle Substances 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 238000012216 screening Methods 0.000 claims description 6
- 230000020477 pH reduction Effects 0.000 claims description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 66
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 37
- 239000010703 silicon Substances 0.000 abstract description 28
- 229910052710 silicon Inorganic materials 0.000 abstract description 27
- 239000011248 coating agent Substances 0.000 abstract description 18
- 238000000576 coating method Methods 0.000 abstract description 18
- 230000008569 process Effects 0.000 abstract description 18
- 239000000463 material Substances 0.000 abstract description 17
- 229910052814 silicon oxide Inorganic materials 0.000 abstract description 17
- 239000010410 layer Substances 0.000 description 31
- 239000000377 silicon dioxide Substances 0.000 description 24
- 239000012071 phase Substances 0.000 description 20
- 239000003575 carbonaceous material Substances 0.000 description 18
- 239000007789 gas Substances 0.000 description 13
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 10
- 229910001416 lithium ion Inorganic materials 0.000 description 10
- 235000012239 silicon dioxide Nutrition 0.000 description 10
- 239000005543 nano-size silicon particle Substances 0.000 description 9
- 229910002804 graphite Inorganic materials 0.000 description 8
- 239000002153 silicon-carbon composite material Substances 0.000 description 8
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 7
- 229910052744 lithium Inorganic materials 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 6
- 239000010406 cathode material Substances 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000011863 silicon-based powder Substances 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 230000001105 regulatory effect Effects 0.000 description 5
- 238000007086 side reaction Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 4
- 239000004327 boric acid Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000009831 deintercalation Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 4
- 239000011856 silicon-based particle Substances 0.000 description 4
- 239000007790 solid phase Substances 0.000 description 4
- 241001391944 Commicarpus scandens Species 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000010426 asphalt Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 238000005253 cladding Methods 0.000 description 3
- 239000011247 coating layer Substances 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000001307 helium Substances 0.000 description 3
- 229910052734 helium Inorganic materials 0.000 description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 238000009830 intercalation Methods 0.000 description 3
- 230000002687 intercalation Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000002210 silicon-based material Substances 0.000 description 3
- 239000011870 silicon-carbon composite anode material Substances 0.000 description 3
- 230000004913 activation Effects 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000003139 buffering effect Effects 0.000 description 2
- 239000006258 conductive agent Substances 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 239000002931 mesocarbon microbead Substances 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 229910021392 nanocarbon Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 230000007704 transition Effects 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
- H01M4/624—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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- 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
- H01M10/058—Construction or manufacture
-
- 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
- H01M4/04—Processes of manufacture in general
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
-
- 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 application provides a composite silicon-oxygen-carbon negative electrode structure and a preparation method thereof, a battery and a preparation method thereof, wherein the composite silicon-oxygen-carbon negative electrode structure comprises: a silicon oxygen negative electrode material; mesophase carbon microbeads; wherein the silicon-oxygen negative electrode material is coated on the mesophase carbon microsphere to form a core-shell structure. The technical scheme provided by the application solves the problems of easy expansion of an internal silicon oxide material and limited cycle performance existing in a carbon-coated silicon type negative electrode material structure in the prior art. The technical scheme provided by the application effectively solves the problem of expansion of the silicon-oxygen anode material in the circulating process while ensuring the coating amount requirement of the silicon-oxygen anode material.
Description
Technical Field
The application relates to the field of lithium battery anode materials, in particular to a composite silicon-oxygen-carbon anode structure and a preparation method thereof, a battery and a preparation method thereof.
Background
With the rapid development of portable electronic devices and electric vehicles, there is a great demand for energy storage systems with high energy density and long cycle life. Lithium ion battery is a secondary batteryThe highest energy density makes it an ideal clean energy source for commercial applications. The negative electrode material is an important factor for improving the energy and cycle life of the lithium ion battery. Among the existing lithium ion battery anode materials, silicon has the highest theoretical specific capacity (4200 mAh.g -1 ) And a lower discharge plateau (< 0.4V vs. Li/Li) + ) The method comprises the steps of carrying out a first treatment on the surface of the Silicon, an element having a storage next to oxygen in the crust, has a huge annual output in industry, and is considered as the next-generation lithium ion battery negative electrode material that is most promising for replacing graphite. However, silicon also has two significant drawbacks that limit the commercial use of silicon anode materials.
Firstly, the silicon anode material has huge volume change in the lithium intercalation and deintercalation process, the expansion can reach 300 percent, and huge internal tension is generated, so that the electrode material is severely pulverized to form an unstable solid electrolyte interface film (SEI), the electrochemical performance is seriously affected, the cycle reversibility is poor, and the coulombic efficiency is low. Unstable SEI breaks down during intercalation and deintercalation of lithium, so that the electrode material is in direct contact with the electrolyte, consuming a lot of lithium ions, repeatedly forming SEI, resulting in rapid capacity decay, especially in full cell systems. The great stress generated by the volume change of the silicon material also easily causes the separation of the active material and the conductive agent, greatly damages the electron transmission path inside the electrode, and even causes the electrode coating to be peeled off from the current collector, so that the battery capacity is continuously reduced until the battery is completely damaged. Another disadvantage of silicon anodes is the low electron conductivity of the silicon material itself (10-3S cm -1 Left and right), and the rate of movement of lithium ions in the silicon anode is low.
Therefore, developing a negative electrode material with higher cycle performance is a technical key point to be solved by those skilled in the art.
Disclosure of Invention
The application provides a composite silicon-oxygen-carbon negative electrode structure, a preparation method, a battery and a preparation method, which can effectively solve the problem of expansion of a silicon-oxygen negative electrode material in a circulating process while ensuring the coating amount requirement of the silicon-oxygen negative electrode material.
According to a first aspect of the present application, there is provided a composite silicon-oxygen-carbon negative electrode structure comprising:
a silicon oxygen negative electrode material;
mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wherein the silicon-oxygen anode material is combined to the plurality of end faces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form a core-shell structure.
Optionally, the diameter of the mesophase carbon microsphere is 3-10um.
Optionally, the thickness of the silicon-oxygen anode material coated on the surface of the mesophase carbon microsphere is as follows: 100nm-1000nm.
Optionally, the volume ratio of the silicon oxygen anode material to the mesophase carbon microsphere is 0.02-0.67.
Optionally, the weight ratio of the silicon oxygen anode material to the mesophase carbon microsphere is: 0.02-0.65.
Optionally, the surface of the mesophase carbon microsphere further comprises a plurality of first surface holes, and the silica anode material is further filled in the plurality of first surface holes; the plurality of first surface pores characterize surface pores added to the surface of the mesophase carbon microsphere after the first treatment of the surface of the mesophase carbon microsphere.
Optionally, after the surfaces of the mesophase carbon microspheres form the plurality of first surface pores, the porosity of the mesophase carbon microspheres is: 20-30%.
Optionally, the volume of the silicon-oxygen anode material filled in the plurality of first surface holes is greater than or equal to 0.03um 3 。
Optionally, the composite silicon-oxygen-carbon anode structure further includes:
a conductive carbon layer; and the conductive carbon layer is coated on the surface of the silicon-oxygen anode material.
Optionally, the thickness of the conductive carbon layer is: 5-50nm.
According to a second aspect of the present application, there is provided a method for preparing a composite silicon-oxygen-carbon negative electrode structure for use in preparing any one of the composite silicon-oxygen-carbon negative electrode structures of the first aspect of the present application, comprising:
providing the silicon oxygen anode material and the mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wrapping the silicon-oxygen anode material on the mesophase carbon microsphere to form the core-shell structure; wherein the silicon-oxygen anode material is bonded to the plurality of end faces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form the core-shell structure.
Optionally, before wrapping the silicon oxygen anode material on the mesophase carbon microsphere, the method further comprises:
screening the mesophase carbon microspheres, wherein the particle size of the mesophase carbon microspheres obtained after screening is as follows: 3-7um.
Optionally, before wrapping the silica anode material on the mesophase carbon microsphere, the method further comprises:
and (3) pore forming is carried out on the surface of the mesophase carbon microsphere so as to form a plurality of first surface pores on the surface of the mesophase carbon microsphere.
Optionally, when pore-forming is performed on the surface of the mesophase carbon microsphere, an acidification treatment mode is adopted for the surface of the mesophase carbon microsphere.
According to a third aspect of the present application, there is provided a battery comprising: the composite silicon-oxygen-carbon negative electrode structure of any one of the first aspect of the application.
According to a fourth aspect of the present application, there is provided a method of manufacturing a battery, comprising: the method for producing a composite silicon-oxygen-carbon negative electrode structure according to any one of the second aspects of the present application.
According to the composite silicon-oxygen-carbon negative electrode structure, the silicon-oxygen negative electrode material is combined to the plurality of end faces of the surface of the intermediate-phase carbon microsphere, so that the silicon-oxygen negative electrode material wraps the intermediate-phase carbon microsphere to form a core-shell structure. In addition, the technical scheme provided by the application also has a good internal carbon conductive network. Meanwhile, as a plurality of exposed end surfaces exist on the surface of the mesophase carbon microsphere, the surface of the mesophase carbon microsphere is active, and can be combined with a sufficient amount of silicon-oxygen cathode material. Therefore, the technical scheme provided by the application effectively solves the problem of expansion in the circulation process while ensuring the coating amount requirement of the silicon-oxygen anode material.
Further, the conductive carbon layer is formed on the surface of the silicon-oxygen negative electrode material, so that the conductivity of the composite silicon-oxygen negative electrode structure can be further improved and ensured, and the formed structure has a good internal carbon conductive network.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a schematic structural diagram of a composite SiOC negative electrode structure according to an embodiment of the present application;
FIG. 2 is a scanning electron microscope image of a composite SiOxycarbon negative electrode structure with a mesophase carbon microsphere particle size of 7 μm according to an embodiment of the present application;
FIG. 3 is a scanning electron microscope image of a composite silicon-oxygen-carbon negative electrode structure with a mesophase carbon microsphere particle size of 5um according to an application example of the present application;
FIG. 4 is a graph showing the specific capacity of a lithium battery fabricated according to a composite silicon-oxygen-carbon negative electrode structure of mesophase carbon microspheres with an average particle size of 5-7 μm according to an application example of the present application;
reference numerals illustrate:
1-mesophase carbon microbeads;
2-silicon oxygen cathode material;
3-conductive carbon layer.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
In the prior art, a silicon anode material is generally prepared in a carbon-coated silicon form, and the anode material with the structure has the following problems: in the carbon-coated silicon negative electrode material, because silicon is coated in carbon, when lithium ions are inserted and extracted, the silicon negative electrode material expands and contracts in volume, so that silicon particles are broken, an SEI film is unstable due to electric contact deterioration, and finally the problems of low efficiency and quick attenuation of circulating capacity of the silicon negative electrode material are caused. The silicon negative electrode material has huge volume change in the lithium intercalation and lithium deintercalation processes, the expansion can reach 300 percent, and huge internal tension is generated, so that the electrochemical performance is seriously affected, the cycle reversibility is poor, and the coulomb efficiency is low; moreover, the great stress caused by the volume change of the silicon material also easily causes the separation of the active material and the conductive agent, greatly damages the electron transmission path inside the electrode, and even causes the stripping of the electrode coating from the current collector, resulting in continuous decrease of the battery capacity until the battery is completely damaged.
Therefore, the traditional carbon-coated silicon structure can inhibit the volume expansion of silicon, which is unfavorable for the release of capacity, and reduce the energy density of the battery; and the innermost layer of the normal silicon oxygen negative electrode is a silicon oxygen negative electrode, so that the stress distribution is very large, the silicon oxygen negative electrode is easy to break, and the reversible circulation of the silicon carbon material cannot be realized. In order to solve the above problems, the prior art has carried out the following studies:
the patent application publication number is: CN 113241426A discloses a carbon composite coated silicon oxide negative electrode material, a preparation method thereof and a lithium ion battery; the preparation method of the anode material comprises the following steps: coating a carbon layer on the surface of the silicon oxide by CVD gas phase coating to obtain gas phase coated silicon oxide; mixing the gas-phase coated silica with asphalt and boric acid, and then carbonizing and sintering to carbonize the asphalt and wrap the asphalt on the surface of the gas-phase coated silica to form a solid-phase coated carbon layer, and volatilizing the boric acid on the surface of the material to form fine holes to obtain a solid-phase coated silica precursor; and preparing the solid phase coated silica precursor into the anode material. Compared with the single CVD coating of the silicon oxide, the technical scheme provided by the application can effectively reduce the CVD coating time, reduce the energy consumption and is more suitable for batch production. Meanwhile, boric acid is added in the solid-phase coating stage, fine holes are formed by volatilization of the boric acid during high-temperature sintering, holes are formed in the surface of the material, the wettability of the surface electrolyte of the material in the battery manufacturing process is improved, the electrolyte holding capacity of the material is improved, and a lithium ion transmission channel of the material in the battery charging and discharging process is increased, so that the purposes of improving the material circulation performance, enhancing the stability of the cathode material and exerting the electrochemical comprehensive performance are achieved, and the performance of the material after twice coating is basically consistent with the performance of the material coated by CVD gas phase alone.
The patent application publication number is: CN 112750993A discloses a silicon carbon composite material comprising: silicon nanoparticles; the metal layer is coated on the surface of the silicon nano-particles; and the carbon material layer is coated on the surface of the metal layer. In the silicon-carbon composite material provided by the application, more metal/silicon contact interfaces are created by the metal layer on the surface of the silicon nano particles, so that a large number of electron conduction paths are added for the silicon nano particles, the effect of a mini current collector is achieved, strong stress support is provided for the volume expansion of the silicon nano particles, the cracking resistance of the silicon nano particles is increased, the silicon nano particles are prevented from being pulverized, the possibility of direct contact between the silicon nano particles and electrolyte is reduced, and the cycle performance of the silicon-carbon composite material is greatly improved. In addition, the carbon material layer on the surface of the metal layer enhances the conductivity of the silicon-carbon composite material, can play a role in buffering volume expansion, reduces side reactions of silicon nano particles and electrolyte, and is beneficial to forming stable SEI. The silicon-carbon composite material has the characteristics of high capacity (for example, the capacity of the silicon-carbon composite material can reach 4.78mAh cm < -2 >), good cycle stability (for example, the average capacity fading rate of each cycle of 1000 cycles of charge and discharge is only 0.068%), and high conductivity.
The patent application publication number is: the application document of CN 115832254A discloses a silicon-carbon composite anode material and a preparation method thereof, and the preparation method provided by the application comprises the following steps: mixing and grinding silicon and silicon dioxide, and then heating to react to generate silicon oxygen steam; synchronously condensing silica vapor and nano carbon material slurry, and simultaneously introducing graphite to obtain a SiO@C@graphite composite material; and (3) introducing a gas carbon source, and forming a carbon coating layer on the surface of the SiO@C@graphite composite material to obtain the silicon-carbon composite anode material. The application realizes that nano-scale silicon oxide is directly and uniformly coated on the surface of graphite, the volume expansion of the silicon oxide is relieved in a nanocrystallization way, meanwhile, the surface of the silicon oxide is provided with a nano carbon material with high conductivity as an inner layer, and an amorphous double coating layer as an outer layer, thereby providing a buffer layer for the expansion of the silicon oxide and improving the conductivity of the silicon oxide. The cycle performance of the silicon oxide can be obviously improved, and the cycle life of the whole silicon-carbon composite anode material is further prolonged. The graphite is added in the preparation process of the silicon oxide, so that the silicon oxide can be directly deposited on the surface of the graphite, the processes of independently preparing massive or granular silicon oxide in the conventional technology, then carrying out multistage crushing, grading and the like are avoided, the industrial process is simplified, the utilization rate of the silicon oxide is improved, and the production cost is reduced.
The patent application publication number is: CN 115911341A discloses a porous silicon-carbon anode material, a preparation method and application, and the anode material provided in the application comprises: the negative electrode material has a core-shell structure, and comprises the following components from inside to outside: porous silica carbon core, transition layer close silicon carbon layer and carbon coating. According to the technical scheme provided by the application, the porous carbon with the silicon particles distributed in the gaps of the carbon skeleton structure of the porous silicon-carbon anode material has a porous gap structure, can provide excellent flexibility nuclear mechanical strength, and can buffer expansion and contraction stress generated by lithium ion deintercalation. The porous carbon with silicon particles distributed in gaps of the carbon skeleton structure, the carbon coating layer and the metal element doped with the compact layer have good conductivity, and the conductivity of the material can be improved. The silicon particles in the porous silicon-carbon anode material are reasonably distributed in the gaps among the porous carbon core-carbon particles, so that the porous silicon-carbon anode material has excellent comprehensive performance, effectively slows down the expansion of the silicon anode material in the circulation process, controls the capacity attenuation and improves the circulation stability.
In summary, various technical schemes provided in the field of negative electrode materials can solve the problem of expansion of the silicon negative electrode material in the circulation process, but the general schemes are different in size, and the method of wrapping the silicon oxygen material layer by the carbon material layer is adopted. Even if the structure of silicon-coated carbon and carbon material re-coated silicon is disclosed, part of carbon coated inside the silicon is activated carbon, and plays a role in buffering during expansion, and the problem of expansion is only partially alleviated although the conductivity is improved at the same time.
In order to further effectively solve the problem of expansion during cycling, the inventors of the present application have undergone a series of repeated designs and experiments:
the inventors found after the study of a large amount of experimental data in the initial study: when the silicon-oxygen negative electrode material is coated on the common carbon material, although the expansion effect is greatly improved, as the common carbon material is formed by stacking hexagonal graphite sheet layer net surfaces, special end surface and basal plane (basalplane) characteristics are formed, and the silicon-oxygen negative electrode material has anisotropic reaction property, wherein the exposed end surface and the limited end surface are adopted, and in the structure of coating the common carbon material by adopting the silicon-oxygen negative electrode material, the coating sites of the silicon-oxygen negative electrode material are extremely limited, so that the actual performance requirement of the negative electrode material can not be met far.
Further, the inventors found that: the intermediate phase carbon microsphere is a spherical particle, and the internal crystal structure of the intermediate phase carbon microsphere is radially arranged to form end face (edge surface) and basal plane (basalplane) characteristics; meaning that there are a number of exposed large number of end faces on its surface. Therefore, the inventor adopts the silicon-oxygen negative electrode material to coat the mesophase carbon microsphere, and finds out through a great number of repeated experiments and tests: on the one hand, compared with the common carbon material, a large number of exposed end surfaces of the surface of the mesophase carbon microsphere can be combined with a sufficient amount of silicon oxygen anode material; on the other hand, compared with the technical scheme that the silicon-oxygen anode material is coated with the common carbon material, the silicon-oxygen anode material is plated on the mesophase carbon microsphere, has more uniform stress distribution and is not easy to break, and the volume expansion rate of the whole silicon-oxygen anode material is only 33-50%, so that the silicon-oxygen anode material has better cycle performance; in addition, the negative electrode material of the internal MCMB (mesophase carbon microsphere) structure also has a good internal carbon conductive network.
The inventor of the present application finally proposes after repeated demonstration of the experimental results and data: coating the silica anode material on the mesophase carbon microsphere to form the silica anode material. According to the technical scheme provided by the application, the silicon-oxygen negative electrode material is skillfully coated on the intermediate phase carbon microsphere, so that the problem of expansion of the silicon-oxygen negative electrode material is solved greatly, and meanwhile, compared with a common carbon material, the intermediate phase carbon microsphere with active surface can be coated with more silicon-oxygen negative electrode materials, so that the technical scheme provided by the application can meet the actual application requirements.
In addition, in the technical scheme provided by the application, the intermediate phase carbon microsphere coated by the silicon-oxygen negative electrode material is almost occupied by the silicon-oxygen negative electrode material at active sites, so that a stable negative electrode material structure is formed, and the problem that the performance of the negative electrode material is affected due to other side reactions generated in the charging and discharging processes of the intermediate phase carbon microsphere with active surface is avoided.
The technical scheme of the application is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.
Referring to fig. 1-4, according to an embodiment of the present application, there is provided a composite silicon-oxygen-carbon anode structure, including:
a silicon oxygen negative electrode material;
mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wherein the silicon-oxygen anode material is bonded to the plurality of end surfaces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form a core-shell structure;
as shown in fig. 1.
In the composite silicon-oxygen-carbon negative electrode structure, the mode of coating the intermediate phase carbon microspheres by the silicon-oxygen negative electrode material is adopted, so that the volume expansion rate of the whole silicon-oxygen negative electrode material is only 33% -50%, and the cycle performance of the negative electrode material is greatly improved.
The composite silicon-oxygen-carbon negative electrode structure provided by the application has the advantages that firstly, the interior of particles is provided with the mesophase carbon microsphere, which means that the bottommost layer of a conductive network is carbon, different from carbon-coated silicon-oxygen, the bottommost layer is contacted with silicon-oxygen, and secondly, the surface of the composite silicon-oxygen-carbon negative electrode structure is coated with a conductive layer, so that the technical scheme provided by the application integrally forms a good internal conductive network.
According to the technical scheme provided by the application, the silicon-oxygen negative electrode material is combined to a plurality of end faces of the surface of the intermediate phase carbon microsphere, so that the silicon-oxygen negative electrode material wraps the intermediate phase carbon microsphere to form a core-shell structure, compared with the technical scheme that the silicon-oxygen negative electrode material is wrapped by a common carbon material in the prior art, the stress distribution is more uniform, the silicon-oxygen negative electrode material is not easy to break, the volume expansion rate of the whole silicon-oxygen negative electrode material is only 33% -50%, and the cycle performance of the negative electrode material is greatly improved. In addition, the technical scheme provided by the application also has a good internal carbon conductive network. Meanwhile, as a plurality of exposed end surfaces exist on the surface of the mesophase carbon microsphere, the surface of the mesophase carbon microsphere is active, and can be combined with a sufficient amount of silicon-oxygen cathode material.
In addition, in the technical scheme provided by the application, the intermediate phase carbon microsphere coated by the silicon-oxygen negative electrode material is almost occupied by the silicon-oxygen negative electrode material at active sites, so that a stable negative electrode material structure is formed, and the problem that the performance of the negative electrode material is affected due to other side reactions generated in the charging and discharging processes of the intermediate phase carbon microsphere with active surface is avoided.
Therefore, the technical scheme provided by the application ensures the coating amount of the silicon-oxygen anode material and simultaneously effectively solves the problem of expansion in the circulating process of the silicon-oxygen anode material. Meanwhile, other side reactions generated in the charge and discharge process of the mesocarbon microbeads with active surfaces are avoided, and higher material performance is realized.
In the prior art, a carbon-coated silicon structure is adopted, mainly in consideration of the capacity problem of the anode material, and the capacity requirement of the anode material cannot be met due to the limited ratio of the silicon-oxygen material in the silicon-coated carbon structure, so that the person skilled in the art cannot think of manufacturing a battery by using the anode material of the silicon-coated carbon structure. In order to overcome the technical prejudice that the prior art adopts a carbon-coated silicon structure consistently, but does not adopt the silicon-coated carbon structure of course; therefore, the technical scheme provided by the application solves the problem of expansion, simultaneously overcomes the problems that the structure of the silicon-coated common carbon material is low and the actual capacity requirement cannot be met, and simultaneously overcomes the technical prejudice of the technical personnel in the art on the capacity defect of the silicon-coated carbon structure.
In one embodiment, the mesophase carbon microbeads have a diameter of 3-10um; the specific examples may be 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, etc., and of course, the application is not limited thereto, and the diameters of the mesophase carbon microspheres are all within the scope of the application as long as they are 3-10um.
In one embodiment, the thickness of the silicon-oxygen anode material coated on the surface of the mesophase carbon microsphere is as follows: 100nm-1000nm; specific examples thereof include 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, and the like, and of course, the application is not limited thereto, and the thickness of the silicon-oxygen anode material coated on the surface of the mesophase carbon microsphere is 100nm to 1000nm, which falls within the protection scope of the application.
However, the larger the thickness of the mesophase carbon microsphere, the higher the specific capacity of the composite type silicon-oxygen-carbon negative electrode structure. Thus, the inventors of the present application found through repeated experiments that: when the thickness of the silicon-oxygen negative electrode material coated on the surface of the mesophase carbon microsphere is 100nm-1000nm, the cyclicity and specific capacity of the composite silicon-oxygen carbon negative electrode structure can be considered, so that the performance of the composite silicon-oxygen carbon negative electrode structure can meet the actual performance requirement of a lithium battery.
Therefore, the technical scheme provided by the embodiment adopts a mode of increasing the wrapping thickness of the silicon-oxygen negative electrode material, and regulates and controls the ratio of the silicon-oxygen negative electrode material to the internal carbon material (the mesophase carbon microsphere), so that the cycle performance and the specific capacity of the composite silicon-oxygen carbon negative electrode structure are regulated, and the cycle performance and the specific capacity are balanced.
In one embodiment, the volume ratio of the silicon oxygen anode material to the mesophase carbon microbeads is 0.02-0.67. Specific examples thereof may be 0.02, 00.5, 0.5, 0.6, 0.67, etc., and of course, the application is not limited thereto, and the volume ratio of the mesophase carbon microsphere is 0.02-0.67, which is within the scope of the application.
In one embodiment, the weight ratio of the silicon oxygen anode material to the mesophase carbon microsphere is: 0.02-0.65. Specific examples thereof include 0.02, 0.06, 0.6, 0.65, etc., and of course, the application is not limited thereto, and the application is within the scope of protection provided that the weight ratio of the mesophase carbon microbeads is 0.02-0.65.
In an alternative embodiment, the surface of the mesophase carbon microsphere further comprises a plurality of first surface holes, and the silica negative electrode material is further filled in the plurality of first surface holes; the first surface pores characterize surface pores (not shown in the surface pore diagram) added to the surface of the mesophase carbon microsphere after the surface of the mesophase carbon microsphere is acidified;
according to the technical scheme provided by the application, the proportion of the silica anode material to the internal carbon material (the mesophase carbon microsphere) is regulated and controlled by arranging the first surface holes on the mesophase carbon microsphere, and the cycle performance and the specific capacity of the composite silica carbon anode structure are regulated, so that the cycle performance and the specific capacity are balanced.
In one embodiment, after the surface of the mesophase carbon microsphere forms the plurality of first surface pores, the mesophase carbon microsphere has a porosity of: 20-30%. Specific examples thereof include 20%, 22%, 24%, 26%, 28%, 30%, etc., and of course, the present application is not limited thereto, as long as the porosity of the mesophase carbon microsphere is: 20-30% of the total weight of the composite material is within the protection scope of the application.
The porosity of the mesophase carbon microsphere is set to be 20-30%, because if the porosity is too large, the structure of the mesophase carbon microsphere is easy to collapse; if the porosity is too small, the number of the silicon-oxygen cathodes is insufficient, so that the capacity of the cathode material is insufficient; the embodiment of the application is obtained through continuous geographic theory verification and actual structure verification, the porosity in the range of 20-30% is ensured not to collapse in the structure of the mesophase carbon microsphere, and the effect of increasing the duty ratio of the silicon-oxygen cathode material in the structure is just realized, so that the balance of the two is realized.
In one embodiment, the volume of the silicon oxide anode material filled in the first surface holes is greater than or equal to 0.03um 3 。
In one embodiment, the composite silicon-oxygen-carbon negative electrode structure further comprises:
a conductive carbon layer; and the conductive carbon layer is coated on the surface of the silicon-oxygen anode material.
The surface of the silicon-oxygen negative electrode material is coated with the conductive carbon layer again, so that the conductive performance of the composite silicon-oxygen carbon negative electrode structure is further improved.
In one embodiment, the conductive carbon layer has a thickness of: 5-50nm; specific examples thereof include 5nm, 6nm, 7nm, 8nm, 20nm, 30nm, 50nm, etc., and of course, the application is not limited thereto, as long as the thickness of the conductive carbon layer is: and 5-50nm, all of which are within the protection scope of the application.
According to an embodiment of the present application, there is further provided a method for preparing a composite silicon-oxygen-carbon negative electrode structure, for preparing the composite silicon-oxygen-carbon negative electrode structure according to any one of the preceding embodiments of the present application, including:
providing the silicon oxygen anode material and the mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wrapping the silicon-oxygen anode material on the mesophase carbon microsphere to form the core-shell structure; wherein the silicon-oxygen anode material is bonded to the plurality of end faces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form the core-shell structure.
According to the technical scheme provided by the application, the silicon-oxygen negative electrode material is combined to the plurality of end faces of the surface of the intermediate phase carbon microsphere, so that the silicon-oxygen negative electrode material wraps the intermediate phase carbon microsphere to form a core-shell structure, the requirement of the coating amount of the silicon-oxygen negative electrode material is ensured, and meanwhile, the problem of expansion in the circulation process of the silicon-oxygen negative electrode material is effectively solved. Meanwhile, other side reactions generated in the charge and discharge process of the mesocarbon microbeads with active surfaces are avoided, and higher material performance is realized.
According to the technical scheme provided by the application, the cycle performance and the specific capacity of the composite silicon-oxygen-carbon negative electrode structure can be regulated by regulating the ratio of the silicon-oxygen negative electrode material to the internal carbon material (mesophase carbon microsphere), so that the cycle performance and the specific capacity are balanced.
In one embodiment, the method further comprises, prior to wrapping the silicon oxygen anode material on the mesophase carbon microbeads:
screening the mesophase carbon microspheres, wherein the particle size of the mesophase carbon microspheres obtained after screening is as follows: 3-7um; specific examples thereof include 3um, 4um, 5um, 6um, 7um, etc., and of course, the present application is not limited thereto, as long as the particle size of the mesophase carbon microsphere is: 3-7um, all are within the scope of the application.
In one embodiment, before wrapping the silica anode material on the mesophase carbon microbeads, the method further comprises:
and (3) pore forming is carried out on the surface of the mesophase carbon microsphere so as to form a plurality of first surface pores on the surface of the mesophase carbon microsphere.
In one embodiment, when the surface of the mesophase carbon microsphere is subjected to pore formation, the surface of the mesophase carbon microsphere is subjected to acidification treatment.
In a specific example, the acidifying treatment of the surface of the mesophase carbon microsphere comprises:
dispersing mesophase carbon microsphere particles in a concentrated acid solution (the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 3:1 at the temperature of 75 ℃), transferring to deionized water after cooling, stirring, centrifuging, continuously cleaning with deionized water until the pH is neutral, and finally filtering.
The performance of the composite silicon-oxygen-carbon negative electrode structure provided by the application is specifically analyzed by the following specific examples:
example 1:
mixing silicon powder and silicon dioxide powder (0.6:1), heating (1200-1400 ℃) until sublimating silicon dioxide negative electrode material gas, wherein the silicon dioxide negative electrode material gas is far away from the silicon powder and silicon dioxide which are mixed and heated in the horizontal direction, and the sublimated gas flows to a chamber where the MCMB is positioned and is separated out on the chamber under the driving of inert gas (nitrogen, argon and helium) so as to realize cladding. The average grain diameter of the composite silicon-oxygen-carbon anode structure is 5um-7um (as shown in fig. 2 and 3, the actual sizes of 3um and 2 um in the figures are 7um and 5um respectively), and the thickness of the silicon-oxygen anode material coated on the surface of the mesophase carbon microsphere is 300nm.
Example 2:
and mixing silicon powder and silicon dioxide powder in a ratio of 0.7:1, heating (1200-1400 ℃) until sublimating silicon dioxide negative electrode material gas, wherein the silicon dioxide negative electrode material gas is far away from the mixed and heated silicon powder and silicon dioxide in the horizontal direction, and the sublimated gas flows to a chamber where the MCMB is positioned and is separated out on the chamber under the driving of inert gas (nitrogen, argon and helium) so as to realize cladding. The average grain diameter of the composite silicon-oxygen-carbon negative electrode structure is 5um-7um (shown in fig. 2 and 3), and the thickness of the silicon-oxygen negative electrode material coated on the surface of the mesophase carbon microsphere is 500nm.
Example 3:
and mixing silicon powder and silicon dioxide powder in a ratio of 0.8:1, heating (1200-1400 ℃) until sublimating silicon dioxide negative electrode material gas, wherein the silicon dioxide negative electrode material gas is far away from the mixed and heated silicon powder and silicon dioxide in the horizontal direction, and the sublimated gas flows to a chamber where the MCMB is positioned and is separated out on the chamber under the driving of inert gas (nitrogen, argon and helium) so as to realize cladding. The average grain diameter of the composite silicon-oxygen-carbon negative electrode structure is 5um-7um (shown in fig. 2 and 3), and the thickness of the silicon-oxygen negative electrode material coated on the surface of the mesophase carbon microsphere is 700nm.
The present application will be described in further detail with reference to examples.
Application example:
the material obtained in example 1 was used as a negative electrode material, and the electrochemical properties thereof were tested by the following specific test procedures:
at the discharge cut-off voltage: under the conditions of 0.05V and 1V of charge cut-off voltage, a charge-discharge instrument is used for carrying out constant-current discharge mode test; the method comprises the following steps: the first cycle charge and discharge test was performed at a C/20 current density, and the fourth cycle and subsequent discharge tests were performed at a C/2 current density.
The test results are shown in FIG. 4, wherein the activation is performed for five times by 0.1C in the first three times of activation at 0.05V-1V, and the long cycle at 0.5C is performed at 0.05V-1V; wherein after 300 circles of circulation, the specific capacity is 669mAh/g, and the corresponding specific capacity retention rate is: 88.3%. Therefore, the silicon-carbon composite anode with the structure has good cycle performance.
The materials obtained in example 2 and example 3 were used as negative electrode materials, and the materials were tested under the same conditions as described above, to obtain a specific capacity of 650mAh/g and 662mAh/g, respectively, after 300 cycles, and specific capacity retention rates of 87.8% and 89.1%, respectively. From this, it can be seen that the silicon carbon composite anode of the structures of example 2 and example 3 also has better cycle performance.
Next, according to an embodiment of the present application, there is provided a battery including: the composite silicon-oxygen-carbon negative electrode structure of any one of the preceding embodiments of the application.
In addition, according to an embodiment of the present application, there is also provided a method for manufacturing a battery, including: the method of preparing a composite silicon-oxygen-carbon negative electrode structure according to any one of the preceding embodiments of the present application.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.
Claims (16)
1. A composite silicon-oxygen-carbon negative electrode structure, comprising:
a silicon oxygen negative electrode material;
mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wherein the silicon-oxygen anode material is combined to the plurality of end faces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form a core-shell structure.
2. The composite silicon-oxygen-carbon negative electrode structure of claim 1, wherein the diameter of the mesophase carbon microsphere is 3-10um.
3. The composite silicon-oxygen-carbon negative electrode structure according to claim 2, wherein the thickness of the silicon-oxygen negative electrode material coated on the surface of the mesophase carbon microsphere is as follows: 100nm-1000nm.
4. A composite silicon-oxygen-carbon negative electrode structure according to claim 3, comprising: the volume ratio of the silicon oxygen anode material to the mesophase carbon microsphere is 0.02-0.67.
5. The composite silicon-oxygen-carbon negative electrode structure according to claim 4, comprising: the weight ratio of the silicon oxygen anode material to the mesophase carbon microsphere is as follows: 0.02-0.65.
6. The composite silicon-oxygen-carbon negative electrode structure according to claim 5, wherein the surface of the mesophase carbon microsphere further comprises a plurality of first surface pores, and the silicon-oxygen negative electrode material is further filled in the plurality of first surface pores; the plurality of first surface pores characterize surface pores added to the surface of the mesophase carbon microsphere after the first treatment of the surface of the mesophase carbon microsphere.
7. The composite silicon-oxygen-carbon negative electrode structure according to claim 6, wherein after the surface of the mesophase carbon microsphere forms the plurality of first surface pores, the porosity of the mesophase carbon microsphere is: 20-30%.
8. The composite silicon-oxygen-carbon negative electrode structure according to claim 7, wherein the volume of the silicon-oxygen negative electrode material filled in the plurality of first surface holes is greater than or equal to 0.03um 3 。
9. The composite silicon-oxygen-carbon negative electrode structure of claim 8, further comprising:
a conductive carbon layer; and the conductive carbon layer is coated on the surface of the silicon-oxygen anode material.
10. The composite silicon-oxygen-carbon negative electrode structure according to claim 9, wherein the conductive carbon layer has a thickness of: 5-50nm.
11. A method for preparing a composite silicon-oxygen-carbon negative electrode structure for manufacturing the composite silicon-oxygen-carbon negative electrode structure as claimed in any one of claims 1 to 10, comprising:
providing the silicon oxygen anode material and the mesophase carbon microbeads; the mesophase carbon microsphere comprises a plurality of basal planes and a plurality of end faces; wherein the end surfaces are distributed on the surface of the mesophase carbon microsphere; the plurality of base surfaces are distributed in the mesophase carbon microsphere;
wrapping the silicon-oxygen anode material on the mesophase carbon microsphere to form the core-shell structure; wherein the silicon-oxygen anode material is bonded to the plurality of end faces of the surface of the mesophase carbon microsphere, so that the silicon-oxygen anode material wraps the mesophase carbon microsphere to form the core-shell structure.
12. The method of preparing a composite silicon-oxygen-carbon negative electrode structure according to claim 11, further comprising, before wrapping the silicon-oxygen-carbon negative electrode material on the mesophase carbon microbeads:
screening the mesophase carbon microspheres, wherein the particle size of the mesophase carbon microspheres obtained after screening is as follows: 3-7um.
13. The method of preparing a composite silicon-oxygen-carbon negative electrode structure according to claim 12, further comprising, before wrapping the silicon-oxygen-carbon negative electrode material on the mesophase carbon microbeads:
and (3) pore forming is carried out on the surface of the mesophase carbon microsphere so as to form a plurality of first surface pores on the surface of the mesophase carbon microsphere.
14. The method for preparing a composite silicon-oxygen-carbon negative electrode structure according to claim 13, wherein the surface of the mesophase carbon microsphere is subjected to acidification treatment during pore-forming.
15. A battery, comprising: the composite silicon-oxygen-carbon negative electrode structure of any one of claims 1-10.
16. A method of manufacturing a battery, comprising: a method of preparing a composite silicon-oxygen-carbon negative electrode structure as claimed in any one of claims 11 to 14.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310911176.1A CN117012966A (en) | 2023-07-24 | 2023-07-24 | Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310911176.1A CN117012966A (en) | 2023-07-24 | 2023-07-24 | Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117012966A true CN117012966A (en) | 2023-11-07 |
Family
ID=88566599
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310911176.1A Pending CN117012966A (en) | 2023-07-24 | 2023-07-24 | Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117012966A (en) |
-
2023
- 2023-07-24 CN CN202310911176.1A patent/CN117012966A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110690420B (en) | Composite material cathode, battery and preparation method thereof | |
| US11196042B2 (en) | Method for preparing silicon-based active material particles for secondary battery and silicon-based active material particles | |
| CN103633306B (en) | A kind of silicon-carbon composite cathode material and preparation method thereof and lithium ion battery | |
| CN107403919B (en) | Composite material of nitrogen-doped carbon material coated with silicon monoxide and preparation method thereof | |
| Zhang et al. | Super‐Assembled Hierarchical CoO Nanosheets‐Cu Foam Composites as Multi‐Level Hosts for High‐Performance Lithium Metal Anodes | |
| CN111293301B (en) | Soft and hard carbon composite porous negative electrode material for sodium ion battery and preparation method thereof | |
| Wu et al. | Disordered carbon tubes based on cotton cloth for modulating interface impedance in β′′-Al 2 O 3-based solid-state sodium metal batteries | |
| CN111048781A (en) | High-compaction-resistant composite conductive agent and application thereof in lithium ion battery | |
| CN108878893B (en) | Modified current collector for negative electrode of quick-charging lithium ion battery and preparation method thereof | |
| CN109841803B (en) | Silicon-carbon composite material, preparation method thereof and secondary battery containing material | |
| CN110890506A (en) | Heat-conducting composite diaphragm for battery and application thereof | |
| CN116779849A (en) | Negative electrode active material, preparation method thereof, electrochemical device and electric equipment | |
| CN110289406B (en) | Three-dimensional cross-linked structure composite electrode material and preparation method and application thereof | |
| CN110550635A (en) | Preparation method of novel carbon-coated silica negative electrode material | |
| CN108565461B (en) | Battery cathode material, preparation method thereof and battery cathode prepared from material | |
| CN108023065A (en) | Lithium ion battery silicon electrode manufacturing method based on selective melting technology | |
| CN114497440B (en) | Negative plate and battery comprising same | |
| CN114127986B (en) | Negative pole piece, electrochemical device and electronic device | |
| CN115566169A (en) | Silica composite material, negative pole piece, lithium ion battery and preparation method thereof | |
| JP7228203B2 (en) | Lithium metal anode and manufacturing method thereof, Lithium ion battery including lithium metal anode | |
| CN117012966A (en) | Composite silicon-oxygen-carbon negative electrode structure and preparation method thereof, battery and preparation method thereof | |
| CN112421027A (en) | Surface modified porous hexagonal Na3V2(PO4)2F3Carbon-coated microsphere and preparation method and application thereof | |
| CN219303702U (en) | Lithium ion battery and negative plate thereof | |
| CN114725361B (en) | Iron-containing oxide coated sulfur doped expanded graphite/silicon electrode material and preparation method thereof | |
| CN115520873B (en) | Modification preparation method of needle-shaped Jiao Jigui carbon electrode material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20240304 Address after: B1001, Wuhan University Shenzhen Industry University Research Building, No. 6 Yuexing Second Road, High tech Zone Community, Yuehai Street, Nanshan District, Shenzhen City, Guangdong Province, 518052 Applicant after: Shenzhen Ningshi Material Technology Co.,Ltd. Country or region after: China Address before: B1001, Wuhan University Shenzhen Industry, University and Research Building, No. 6, Yuexing Second Road, Gaoxin District Community, Yuehai Street, Nanshan District, Shenzhen, Guangdong Province, 518000 Applicant before: Shenzhen Soft Silicon Material Technology Co.,Ltd. Country or region before: China |
|
| TA01 | Transfer of patent application right |