CN114843491A - High-capacity and high-cycle-stability cathode material and preparation method thereof - Google Patents
High-capacity and high-cycle-stability cathode material and preparation method thereof Download PDFInfo
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- 238000000576 coating method Methods 0.000 claims description 20
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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
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
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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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- 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 discloses a high-capacity and high-cycle stability cathode material and a preparation method thereof, which belong to the technical field of new energy, wherein the preparation method of the high-capacity and high-cycle stability cathode material comprises the following steps: depositing a lithium source on the surface of the silicon to obtain a lithium-supplementing coating layer; preparing a carbon coating layer on the surface of the lithium supplement coating layer to obtain a pre-lithiated silicon-carbon material; mixing the silicon-carbon material with graphite to obtain a silicon-carbon-graphite mixture; preparing a lithium supplementing coating layer on the surface of the silicon-carbon-graphite mixture to obtain a target pre-lithium mixture; and preparing a carbon coating layer on the surface of the pre-lithium mixture to obtain the target negative electrode material. The method can effectively improve the energy density of the cathode material; the first coulombic efficiency of the negative electrode material is obviously improved; meanwhile, the stability of the structure can be better maintained, and the cycle performance is improved; the reaction depth of the contact prelithiation is obviously enhanced, and the capacity retention rate and the cycling stability of the battery are improved.
Description
Technical Field
The application belongs to the technical field of new energy, and particularly relates to a high-capacity and high-cycle-stability cathode material and a preparation method thereof.
Background
With the rapid development of the new energy automobile industry, lithium ion batteries with high energy density, high power density and long cycle life are widely researched by people and serve as one of main materials of the lithium ion batteries.
The current commercialized graphite cathode material cannot meet the increasing market demand due to its own low theoretical capacity of short plates (372mAh/g), so that other cathode materials capable of replacing graphite are urgently needed to be found. Research shows that among novel negative electrode materials, silicon materials are concerned because of the advantages of high theoretical capacity (4200mAh/g), abundant reserves, low discharge voltage and the like. Although the silicon negative electrode material has many advantages, the bottleneck of the silicon negative electrode material still exists, and the silicon itself has huge volume expansion (> 400%) and shrinkage in the charging and discharging processes, which can cause pulverization of the active material, peeling from the current collector and continuous fracture and generation of SEI film, thereby seriously affecting the cycle performance of the battery. Therefore, the present application provides a method for preparing a high-capacity and high-cycle-stability negative electrode material to solve the problem.
Disclosure of Invention
Objects of the invention
The application aims to provide a high-capacity and high-cycle-stability cathode material and a preparation method thereof so as to solve the problem of low capacity of the conventional graphite cathode.
(II) technical scheme
According to a first aspect of embodiments of the present application, there is provided a method for preparing a high-capacity high-cycle-stability anode material, which may include:
depositing a lithium source on the surface of the silicon to obtain a lithium-supplementing coating layer;
preparing a carbon coating layer on the surface of the lithium supplement coating layer to obtain a pre-lithiated silicon-carbon material;
mixing the silicon-carbon material with graphite to obtain a silicon-carbon-graphite mixture;
preparing a lithium supplementing coating layer on the surface of the silicon-carbon-graphite mixture to obtain a target pre-lithium mixture;
and preparing a carbon coating layer on the surface of the pre-lithium mixture to obtain the target negative electrode material.
In some optional embodiments of the present application, the depositing a lithium source on the surface of the silicon comprises:
and depositing a lithium source on the surface of the silicon by means of atomic layer deposition.
In some optional embodiments of the present application, the lithium source comprises: metallic lithium, Li 2 CO 3 Or LiF.
In some alternative embodiments of the present application, preparing a carbon coating layer on a surface of the lithium-supplemented coating layer comprises:
and preparing a carbon coating layer on the surface of the lithium supplement coating layer by introducing acetylene gas.
In some optional embodiments of the present application, the pulverizing and mixing the silicon-carbon material with graphite comprises:
and (3) crushing and mixing the silicon-carbon material and graphite by using a ball mill.
In some optional embodiments of the present application, the mass ratio of the silicon carbon material to the graphite is 5: 95.
in some alternative embodiments of the present application, preparing a lithium-supplementing coating layer on a surface of the mixture comprises:
and preparing a lithium-supplementing coating layer on the surface of the target mixture by means of atomic layer deposition.
In some optional embodiments of the present application, after preparing a lithium-supplementing coating layer on the surface of the mixture to obtain a target pre-lithium mixture, the method for preparing the negative electrode material further comprises:
and carrying out carbon coating by utilizing a solid-phase carbon source and a gas-phase carbon source to obtain the pre-lithiated silicon-carbon-graphite composite negative electrode material.
According to a second aspect of the embodiments of the present application, there is provided an anode material, which can be prepared by the method for preparing the anode material with high capacity and high cycle stability according to any one of the embodiments of the first aspect.
According to a third aspect of embodiments of the present application, there is provided a lithium ion battery, which may include: the negative electrode material of the second aspect.
In some optional embodiments of the present application, the method comprises: button cells, pouch cells, or hard-shell cells.
(III) advantageous effects
The technical scheme of the invention has the following beneficial technical effects:
the method in the embodiment can effectively improve the energy density of the common graphite cathode material by doping the pre-lithiated silicon-carbon material; the purpose of lithium supplement on the material layer can be realized in the preparation process, the lithium supplement is very uniform, and the first coulombic efficiency of the negative electrode composite material is obviously improved; meanwhile, as the content of lithium in the inner part is higher, more silicon-lithium alloy can be formed to serve as a stable frame, the stability of the structure can be better maintained, and the expansion of the material is further relieved and the cycle performance is improved by combining a carbon coating on the surface. The lithium-containing layer interface in the prelithiation cathode is used as an artificial electronic path and is responsible for stabilizing the electron transmission between two phase interfaces in the prelithiation process, so that the damage of the interface stress fluctuation to the electronic path structure is avoided, the reaction depth of contact prelithiation is obviously enhanced, the utilization rate of the lithium-containing layer is improved, the yield of the formation of inert lithium is reduced, and the capacity retention rate and the cycle stability of the battery are improved. Meanwhile, the problem of volume expansion of silicon in the circulation process can be effectively solved by coating the silicon with carbon twice, and the circulation stability of the battery is remarkably improved.
Drawings
FIG. 1 is a flow chart of a method for preparing an anode material in an exemplary embodiment of the present application;
fig. 2 is a schematic cross-sectional view of an anode material in an exemplary embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to the accompanying drawings in combination with the detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present application. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present application.
In the drawings, a schematic diagram of a layer structure according to an embodiment of the application is shown. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity. The shapes of various regions, layers, and relative sizes and positional relationships therebetween shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, as actually required.
It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is noted that the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.
The negative electrode material and the preparation method thereof provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios thereof.
As shown in fig. 1, in a first aspect of embodiments of the present application, there is provided a method of preparing an anode material, which may include:
s110: depositing a lithium source on the surface of the silicon to obtain a lithium-supplementing coating layer;
s120: preparing a carbon coating layer on the surface of the lithium supplement coating layer to obtain a pre-lithiated silicon-carbon material;
s130: mixing the silicon-carbon material with graphite to obtain a silicon-carbon-graphite mixture;
s140: preparing a lithium supplementing coating layer on the surface of the silicon-carbon-graphite mixture to obtain a target-pre-lithium mixture;
s150: and preparing a carbon coating layer on the surface of the pre-lithium mixture to obtain the target negative electrode material.
For the sake of clarity, the following steps are detailed below:
first, step S110: and depositing a lithium source on the surface of the silicon to obtain a lithium-supplementing coating layer.
In the step, the lithium source is deposited on the surface of the silicon by adopting a chemical vapor deposition method or an atomic deposition method; to save costs, an exemplary method of atomic deposition is used to deposit a lithium source on the surface of the silicon. The lithium source may be metallic lithium, lithium amide, lithium oxide, lithium carbonate, etc., and exemplarily, the lithium source is metallic lithium, Li 2 CO 3 Or LiF. The thickness of the silicon-deposited lithium source can be in the range of 10nm to 50nm, and illustratively, the thickness of the lithium source is 10nm, 20nm, 30nm, 40nm, 50 um.
Next is step S120: and preparing a carbon coating layer on the surface of the lithium supplement coating layer to obtain the pre-lithiated silicon-carbon material.
The carbon coating layer can be prepared in a gas phase coating mode, a liquid phase coating mode or a solid phase coating mode. Illustratively, the gas phase coating may employ acetylene; the liquid phase coating can adopt asphalt; the solid phase coating can be glucose. The carbon coating layer can be prepared by adopting a sintering process, and the sintering temperature can be between 800 ℃ and 1100 ℃. Exemplary sintering temperatures are 800 ℃, 900 ℃, 1000 ℃, 1100 ℃. The heat preservation can be carried out after sintering, and the heat preservation time can be 2-6h, and is 2h, 4h and 6h as an example.
Next, step S130: and mixing the silicon-carbon material with graphite to obtain a silicon-carbon-graphite mixture.
In the step, the silicon-carbon material and the graphite are mixed, and the silicon-carbon material and the graphite can be crushed and mixed by using a ball mill. The ball milling mixing time can be between 0.5 and 1.5 hours, and illustratively, the ball milling mixing time is 0.5 hour; 1 h; and (5) h. The rotation speed of the ball mill can be controlled between 200r/min and 400 r/min. Illustratively, the rotation speed of the ball mill is 200 r/min; 300 r/min; 400 r/min.
Then step S140: and preparing a lithium supplementing coating layer on the surface of the silicon-carbon-graphite mixture to obtain a target-pre-lithium mixture.
The lithium-supplementing coating layer prepared in the step can be used for uniformly depositing lithium metal and Li on the surface of the lithium-supplementing coating layer in an atomic deposition mode 2 CO 3 Or LiF.
Finally, step S150: and preparing a carbon coating layer on the surface of the pre-lithium mixture to obtain the target negative electrode material.
The carbon coating layer prepared in the step can adopt vapor deposition, liquid deposition or solid deposition. Illustratively, vapor deposition may employ acetylene; the liquid phase deposition can adopt asphalt; the solid phase deposition can be performed using glucose. In the vapor deposition process, a mode of introducing acetylene and nitrogen can be adopted, and the mixing ratio of the acetylene to the nitrogen can be 1:1-1: 3. The carbon coating layer can be prepared by adopting a sintering process, and the sintering temperature can be between 800 ℃ and 1100 ℃. Exemplary sintering temperatures are 800 ℃, 900 ℃, 1000 ℃, 1100 ℃.
In some optional embodiments of the present application, the depositing a lithium source on the surface of the silicon comprises:
and depositing a lithium source on the surface of the silicon by means of atomic layer deposition. The method adopts the atomic layer deposition mode to carry out the prelithiation, does not need to use chemical reagents in the operation process, has no pollution to the environment and is very environment-friendly
In some optional embodiments of the present application, the lithium source may include: metallic lithium, Li 2 CO 3 Or LiF.
In some alternative embodiments of the present application, preparing a carbon coating layer on a surface of the lithium-supplemented coating layer comprises:
and preparing a carbon coating layer on the surface of the lithium supplement coating layer by introducing acetylene gas.
In some optional embodiments of the present application, the mixing the silicon carbon material with graphite comprises:
and (3) crushing and mixing the silicon-carbon material and graphite by using a ball mill.
In some optional embodiments of the present application, the mass ratio of the silicon carbon material to the graphite is 5: 95.
in some alternative embodiments of the present application, preparing a lithium-supplementing coating layer on a surface of the target mixture includes:
and preparing a lithium supplementing coating layer on the surface of the target mixture by means of atomic layer deposition.
In some optional embodiments of the present application, after preparing a lithium-supplementing coating layer on a surface of the target mixture to obtain a target anode material, the method for preparing the anode material further comprises:
and carrying out carbon coating by utilizing a solid-phase carbon source and a gas-phase carbon source to obtain the pre-lithiated silicon-carbon-graphite composite negative electrode material. Wherein, the solid phase carbon source and the gas phase carbon source can be acetylene and the like.
Example 1
Preparation of a prelithiation modified anode material:
1) under nitrogen atmosphere, 10g of nano-scale Si powder is evenly deposited with a layer of metal lithium of about 15nm on the surface by an atomic deposition mode;
2) putting the pre-lithiated Si into a tubular furnace with nitrogen as protective gas, starting to introduce acetylene gas at the flow rate of 3L/min, raising the temperature to 1000 ℃ at the temperature rise rate of 5 ℃/min, and preserving the heat for 4 hours to finish carbon coating of the pre-lithiated Si;
3) taking the product obtained in the step 2) and the artificial graphite with the mass of 5g and 95g respectively, weighing 50g of agate balls with the diameter of 10mm, mixing the agate balls in a ball mill protected by inert gas at the speed of 300r/min for 1h, and exchanging the running direction of the ball mill every 20min in an alternate running mode;
4) under the nitrogen atmosphere, uniformly depositing a layer of about 50nm of metal lithium on the surface of 100g of the powder material prepared in the step 3) in an atomic deposition mode;
5) putting the powder material prepared in the step 4) into a rotary furnace, introducing mixed gas of acetylene and nitrogen (the mixing ratio is 1:3) at high temperature, carrying out gas-phase carbon coating, reacting at 900 ℃ for 3h, and cooling to room temperature to obtain a pre-lithiated silicon carbon-graphite composite material;
6) the material prepared in example 1 is assembled into a button cell for electrochemical performance test analysis, and the specific scheme is as follows: the preparation material, the conductive agent SP, the conductive agent VGCF and the adhesive PAA are mixed according to the proportion of 80:5:5:10 to prepare a model 2025 button cell, a counter electrode is a lithium sheet, a diaphragm is a Celgard 2400 microporous polypropylene film, the charge-discharge cutoff voltage is 0.005-1.5V, the discharge multiplying power is 0.1C and 0.02C, and the charge multiplying power is 0.1C.
The test results are: the first discharge capacity is 440.42mAh/g, the first charge capacity is 460.1mAh/g, the first efficiency is 95.72%, the cycle frequency can reach 8000 times, and the capacity retention rate is 85%, compared with the current commercial material, the silicon-carbon material prepared based on the technology is improved in capacity and cycle stability.
Example 2
Preparation of a prelithiation modified anode material:
1) 10g of nano-scale Si powder is evenly deposited with a layer of Li of about 20nm on the surface by means of atomic deposition 2 CO 3 ；
2) Putting the pre-lithiated Si into a tubular furnace taking nitrogen as a protective gas, starting to introduce acetylene gas at the flow rate of 3L/min, raising the temperature to 1000 ℃ at the temperature rise rate of 5 ℃/min, and preserving the temperature for 4h to complete carbon coating of the pre-lithiated Si;
3) taking the product obtained in the step 2) and artificial graphite with the mass of 5g and 95g respectively, weighing 50g of agate balls with the diameter of 10mm, mixing the agate balls in a ball mill under the protection of inert gas at a speed of 300r/min for 1h, and exchanging the running direction of the ball mill every 20min in an alternative running mode;
4) under the nitrogen atmosphere, 100g of the powder material prepared in the step 3) is uniformly distributed on the surface of the powder material in an atomic deposition modeDepositing a layer of about 70nm Li 2 CO 3 ；
5) Putting the powder material prepared in the step 4) into a CVD rotary furnace, introducing mixed gas of acetylene and nitrogen (the mixing ratio is 1:1) at high temperature, carrying out gas-phase carbon coating, wherein the reaction temperature is 900 ℃, the reaction time is 3h, and cooling to room temperature to obtain a pre-lithiated silicon carbon-graphite material which has a core-shell structure and is completely carbon-coated;
example 3
Preparation of a prelithiation modified anode material:
1) uniformly depositing a layer of LiF with the thickness of about 30nm on the surface of 10g of nano-scale Si powder in an atomic deposition mode;
2) putting the pre-lithiated Si into a tubular furnace taking nitrogen as a protective gas, starting to introduce acetylene gas at the flow rate of 3L/min, raising the temperature to 1000 ℃ at the temperature rise rate of 5 ℃/min, and preserving the temperature for 4h to complete carbon coating of the pre-lithiated Si;
3) taking the product obtained in the step 2) and the artificial graphite with the mass of 5g and 95g respectively, weighing 50g of agate balls with the diameter of 10mm, mixing the agate balls in a ball mill protected by inert gas at the speed of 300r/min for 1h, and exchanging the running direction of the ball mill every 20min in an alternate running mode;
4) uniformly depositing a layer of LiF with the diameter of about 60nm on the surface of 100g of the powder material prepared in the step 3) in an atomic deposition mode in a nitrogen atmosphere;
5) putting the powder material prepared in the step 4) into a CVD rotary furnace, introducing mixed gas of acetylene and nitrogen (the mixing ratio is 1:1) at high temperature, carrying out gas-phase carbon coating, wherein the reaction temperature is 900 ℃, the reaction time is 3h, and cooling to room temperature to obtain a pre-lithiated silicon carbon-graphite material which has a core-shell structure and is completely carbon-coated;
according to the preparation method of the embodiment, the lithium supplement coating layer is prepared on the surface of the silicon in an atomic layer deposition mode; then preparing a carbon coating layer on the surface of the lithium supplement coating layer by introducing acetylene gas to obtain a pre-lithiated silicon-carbon material; and then ball-milling the silicon-carbon material and graphite together, preparing a lithium-supplementing coating layer on the surface of the obtained mixture in an atomic layer deposition mode, and finally performing secondary carbon coating by using asphalt to obtain the pre-lithiated silicon-carbon-graphite composite negative electrode material. The method has the advantages that the lithium is pre-prepared for the first time in the process of preparing the silicon carbon, and the lithium is pre-prepared for the second time after the silicon carbon-graphite composite material is coated, so that the overall structure is more favorable for maintaining the stability of the material, and the cycle performance is improved, thereby achieving the purpose of generating a novel cathode material with high capacity, high first efficiency and long cycle.
In summary, the first aspect of the embodiments of the present application is directed to a method for preparing an anode material, in which the energy density of a common graphite anode material can be effectively increased by doping a pre-lithiated silicon-carbon material; the purpose of lithium supplement on the material layer can be realized in the preparation process, the lithium supplement is very uniform, and the first coulombic efficiency of the negative electrode composite material is obviously improved; meanwhile, as the content of lithium in the silicon-lithium alloy is higher, more silicon-lithium alloys can be formed to serve as a stable frame, the stability of the structure can be better maintained, and the expansion of the material is further relieved by combining with a carbon coating on the surface, so that the cycle performance is improved. The lithium-containing layer interface in the prelithiation cathode is used as an artificial electronic path and is responsible for stabilizing the electron transmission between two phase interfaces in the prelithiation process, so that the damage of the interface stress fluctuation to the electronic path structure is avoided, the reaction depth of contact prelithiation is obviously enhanced, the utilization rate of the lithium-containing layer is improved, the yield of the formation of inert lithium is reduced, and the capacity retention rate and the cycle stability of the battery are improved. Meanwhile, the problem of volume expansion of silicon in the circulation process can be effectively solved by carbon coating twice on the silicon, the circulation stability is obviously improved, the pre-lithiation is carried out in an atomic layer deposition mode, no chemical reagent is used in the operation process, the environment is not polluted, and the method is very environment-friendly.
According to a second aspect of embodiments of the present application, there is provided an anode material, which can be prepared by the method for preparing an anode material according to any one of the embodiments of the first aspect.
According to a third aspect of embodiments of the present application, there is provided a lithium ion battery, which may include: the negative electrode material of the second aspect.
In some optional embodiments of the present application, the method comprises: button cells, pouch cells, or hard-shell cells.
While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (8)
1. A preparation method of a high-capacity and high-cycle-stability negative electrode material is characterized by comprising the following steps:
depositing a lithium source on the surface of the silicon to obtain a lithium-supplementing coating layer;
preparing a carbon coating layer on the surface of the lithium supplement coating layer to obtain a pre-lithiated silicon-carbon material;
mixing the silicon-carbon material with graphite to obtain a silicon-carbon-graphite mixture;
preparing a lithium supplementing coating layer on the surface of the silicon-carbon-graphite mixture to obtain a target pre-lithium mixture;
and preparing a carbon coating layer on the surface of the pre-lithium mixture to obtain the target negative electrode material.
2. The method of claim 1, wherein depositing a lithium source on the surface of the silicon comprises:
and depositing a lithium source on the surface of the silicon by means of atomic layer deposition, wherein the deposition thickness is 10-50 nm.
3. The method for preparing a high-capacity high-cycle-stability negative electrode material according to claim 1, wherein preparing a carbon coating layer on the surface of the lithium-supplementing coating layer comprises:
and preparing a carbon coating layer on the surface of the lithium supplement coating layer by introducing acetylene gas.
4. The method for preparing a high-capacity high-cycle-stability negative electrode material according to claim 1, wherein preparing a lithium-supplementing coating layer on the surface of the mixture comprises:
and preparing a lithium-supplementing coating layer on the surface of the target mixture by means of atomic layer deposition.
5. The method for preparing a high-capacity high-cycle-stability negative electrode material according to claim 1, wherein after preparing a lithium-supplementing coating layer on the surface of the mixture to obtain the target pre-lithium mixture, the method for preparing the negative electrode material further comprises:
and carrying out carbon coating by utilizing a solid-phase carbon source and a gas-phase carbon source to obtain the pre-lithiated silicon-carbon-graphite composite negative electrode material.
6. A negative electrode material characterized by being produced by the method for producing a high-capacity high-cycle-stability negative electrode material according to any one of claims 1 to 5.
7. A lithium ion battery, comprising: the negative electrode material of claim 6.
8. The lithium ion battery of claim 7, comprising: button cells, pouch cells, or hard-shell cells.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115513444A (en) * | 2022-11-16 | 2022-12-23 | 江苏正力新能电池技术有限公司 | Silicon @ carbon-graphite composite negative electrode material, composite layer negative electrode plate and secondary battery |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100173198A1 (en) * | 2009-01-02 | 2010-07-08 | Aruna Zhamu | Secondary lithium ion battery containing a prelithiated anode |
| CN108028368A (en) * | 2015-09-17 | 2018-05-11 | 罗伯特·博世有限公司 | Prelithiation and the active material of positive electrode of carbon coating |
| CN111554910A (en) * | 2020-05-19 | 2020-08-18 | 溧阳天目先导电池材料科技有限公司 | Lithium battery negative electrode material containing pre-lithiated silylene material, preparation method thereof and lithium battery |
-
2022
- 2022-05-13 CN CN202210524562.0A patent/CN114843491A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100173198A1 (en) * | 2009-01-02 | 2010-07-08 | Aruna Zhamu | Secondary lithium ion battery containing a prelithiated anode |
| CN108028368A (en) * | 2015-09-17 | 2018-05-11 | 罗伯特·博世有限公司 | Prelithiation and the active material of positive electrode of carbon coating |
| CN111554910A (en) * | 2020-05-19 | 2020-08-18 | 溧阳天目先导电池材料科技有限公司 | Lithium battery negative electrode material containing pre-lithiated silylene material, preparation method thereof and lithium battery |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115513444A (en) * | 2022-11-16 | 2022-12-23 | 江苏正力新能电池技术有限公司 | Silicon @ carbon-graphite composite negative electrode material, composite layer negative electrode plate and secondary battery |
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