CN116621160A - Oxygen-doped hard carbon material, preparation method thereof, hard carbon negative electrode material and battery - Google Patents

Oxygen-doped hard carbon material, preparation method thereof, hard carbon negative electrode material and battery Download PDF

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Publication number
CN116621160A
CN116621160A CN202310909851.7A CN202310909851A CN116621160A CN 116621160 A CN116621160 A CN 116621160A CN 202310909851 A CN202310909851 A CN 202310909851A CN 116621160 A CN116621160 A CN 116621160A
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Prior art keywords
oxygen
hard carbon
carbon material
doped
doped hard
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Inventor
谌庆春
王铈汶
林颖鑫
朱开达
张敏
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Shenzhen Haichen Energy Storage Control Technology Co ltd
Xiamen Hithium Energy Storage Technology Co Ltd
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Shenzhen Haichen Energy Storage Control Technology Co ltd
Xiamen Hithium Energy Storage Technology Co Ltd
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Priority to CN202310909851.7A priority Critical patent/CN116621160A/en
Publication of CN116621160A publication Critical patent/CN116621160A/en
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • 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
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • 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
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

The invention discloses an oxygen-doped hard carbon material and a preparation method thereof, a hard carbon negative electrode material and a battery, wherein the preparation method of the oxygen-doped hard carbon material comprises the following steps: putting a hard carbon material and grinding balls into a ball milling tank of plasma ball milling equipment, introducing oxygen-containing gas into the ball milling tank until the air pressure in the ball milling tank reaches a first preset value, and operating the plasma ball milling equipment to ionize the oxygen-containing gas in the ball milling tank and move the ball milling tank to form an oxygen-doped hard carbon material, and separating the oxygen-doped hard carbon material from the grinding balls to obtain the oxygen-doped hard carbon material. According to the preparation method of the oxygen-doped hard carbon material, provided by the embodiment of the invention, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material can be increased, and the rate capability is improved; in addition, the granularity of the oxygen doped hard carbon material is smaller, the diffusion path of ions is shortened, and meanwhile, the surface defects of the oxygen doped hard carbon material are increased, so that the rate capability can be further improved.

Description

Oxygen-doped hard carbon material, preparation method thereof, hard carbon negative electrode material and battery
Technical Field
The invention relates to the field of household appliances, in particular to an oxygen doped hard carbon material, a preparation method thereof, a hard carbon negative electrode material and a battery.
Background
Some batteries, such as sodium ion batteries, use hard carbon materials as the negative electrode material, but the hard carbon materials have the problem of smaller specific capacity, so that the rate performance of the negative electrode material is poor. In the related art, the specific capacity of the hard carbon negative electrode material can be improved by doping the hard carbon material with hetero atoms, wherein oxygen doping is a simple and effective method, oxygen is introduced into the hard carbon negative electrode material, oxygen-containing functional groups can be formed on the surface of the hard carbon material, the specific capacity of the hard carbon negative electrode material is improved, and the rate capability of the hard carbon negative electrode material is improved.
In the related art, the oxygen element content obtained by the preparation method of the oxygen doped hard carbon is less, the specific capacity of the hard carbon anode material is smaller, and the improvement of the rate capability is not facilitated.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide a method for preparing an oxygen-doped hard carbon material, by which more oxygen elements can be introduced into the hard carbon material, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, thereby improving the specific capacity of the oxygen-doped hard carbon material and the rate capability of a battery using the oxygen-doped hard carbon material; in addition, the preparation method can lead the granularity of the oxygen-doped hard carbon material to be smaller, shorten the diffusion path of ions, improve the rate capability of the battery applying the oxygen-doped hard carbon material, increase the surface defects of the oxygen-doped hard carbon material, and improve the specific capacity of the oxygen-doped hard carbon material, thereby further improving the rate capability of the battery applying the oxygen-doped hard carbon material.
The invention also provides an oxygen doped hard carbon material.
The invention also provides a hard carbon anode material with the oxygen doped hard carbon material.
The invention also provides a battery with the hard carbon anode material.
According to an embodiment of the first aspect of the present invention, a method for preparing an oxygen doped hard carbon material includes: putting hard carbon materials and grinding balls into a ball milling tank of plasma ball milling equipment; introducing oxygen-containing gas into the ball milling tank until the air pressure in the ball milling tank reaches a first preset value; the plasma ball milling device operates to ionize an oxygen-containing gas within the ball milling tank and to move the ball milling tank to form an oxygen-doped hard carbon material; separating the oxygen-doped hard carbon material from the grinding balls to obtain the oxygen-doped hard carbon material.
According to the preparation method of the oxygen-doped hard carbon material, more oxygen elements can be introduced into the hard carbon material through the preparation method, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, the specific capacity of the oxygen-doped hard carbon material can be improved, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved; in addition, the preparation method can lead the granularity of the oxygen-doped hard carbon material to be smaller, shorten the diffusion path of ions, improve the rate capability of the battery applying the oxygen-doped hard carbon material, increase the surface defects of the oxygen-doped hard carbon material, and improve the specific capacity of the oxygen-doped hard carbon material, thereby further improving the rate capability of the battery applying the oxygen-doped hard carbon material.
According to some embodiments of the invention, the mass ratio of the grinding balls to the hard carbon material is 5:1 to 50:1.
According to some embodiments of the invention, the grinding balls comprise first and second grinding balls of different diameters, the ratio of the diameters of the first and second grinding balls ranges from 1.5 to 3.5, and the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball ranges from 0.8 to 1.2.
According to some embodiments of the invention, before introducing the oxygen-containing gas into the ball milling tank and after placing the hard carbon material and the grinding balls into the ball milling tank, the ball milling tank is vacuumized until the air pressure in the ball milling tank reaches a second preset value, wherein the second preset value is smaller than the first preset value.
According to some embodiments of the invention, the second preset value ranges from 0.0001 Pa to 0.001Pa.
According to some embodiments of the invention, the oxygen-containing gas comprises oxygen.
According to some embodiments of the invention, the oxygen-containing gas comprises an argon-oxygen mixture.
According to some embodiments of the invention, the first preset value ranges from 10000 to 100000Pa.
According to some embodiments of the invention, the hard carbon material has a particle size volume distribution of: dv50=12 to 18um.
According to some embodiments of the invention, the plasma ball milling device comprises a discharge electrode rod and a ball mill, wherein the ball mill tank is arranged on the ball mill, the ball mill is used for driving the ball mill tank to move, and a ball milling cavity for accommodating the hard carbon material and the grinding balls is defined between the discharge electrode rod and the ball mill tank; the plasma ball milling equipment comprises a plasma power supply, the discharge electrode rod is suitable for being connected with the positive electrode of the plasma power supply, and the ball milling tank is suitable for being connected with the negative electrode of the plasma power supply so as to form an electric field between the ball milling tank and the discharge electrode rod.
According to some embodiments of the invention, the parameters of the electric field include: the discharge voltage is 10-30 kV, the discharge frequency is 7-12 kHz, and the discharge current is 1-3A.
According to some embodiments of the invention, the ball mill comprises a ball mill body and a motor, wherein the motor is rotatably connected with the ball mill body to drive the ball mill body to vibrate, the ball mill tank is arranged on the ball mill body, the rotating speed of the motor is 1000-1500 rpm, the vibration amplitude of the ball mill tank is 7-10 mm, and the ball milling time is 1-10 h.
According to the oxygen-doped hard carbon material of the embodiment of the second aspect of the invention, the mass percentage of oxygen element in the oxygen-doped hard carbon material is 0.05% -1.0%.
According to the oxygen-doped hard carbon material provided by the embodiment of the invention, the content of oxygen elements in the oxygen-doped hard carbon material can be more reasonable, and the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, so that the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of a battery applying the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, so that the first coulomb efficiency of the oxygen-doped hard carbon material is ensured.
According to some embodiments of the invention, the oxygen doped hard carbon material has a particle size volume distribution that satisfies: dv50=3 to 8um.
According to some embodiments of the invention, the particle size number distribution of the oxygen doped hard carbon material satisfies: dn10=0.2 to 0.7um, dn50=0.5 to 1.5um.
According to some embodiments of the invention, the oxygen-doped hard carbon material has a specific surface area of 2 to 6 m 2 /g。
According to some alternative embodiments of the present invention, the oxygen doped hard carbon material is prepared by the method for preparing an oxygen doped hard carbon material according to the embodiment of the first aspect of the present invention.
The hard carbon negative electrode material according to the embodiment of the third aspect of the present invention includes the oxygen doped hard carbon material according to the embodiment of the above second aspect of the present invention.
According to the hard carbon negative electrode material provided by the embodiment of the invention, through the application of the oxygen-doped hard carbon material, the oxygen element content in the oxygen-doped hard carbon material can be more reasonable, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of a battery applying the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, thereby ensuring the first coulomb efficiency of the oxygen-doped hard carbon material.
According to some embodiments of the invention, a metal is used as a negative electrode material to prepare a negative electrode plate of a half battery, the hard carbon negative electrode material is used as a positive electrode material to prepare a positive electrode plate of the half battery, and the half battery negative electrode plate and the half battery positive electrode plate are assembled into the half battery; wherein the half-cell has a discharge capacity of more than 0.1V and accounts for more than 32% of the total discharge capacity; and/or, the 0.1C discharge capacity of the half cell accounts for more than 85% of the total discharge capacity.
A battery according to an embodiment of the fourth aspect of the present invention includes: a housing; the electrode assembly is arranged in the shell and comprises a negative electrode plate and a positive electrode plate, the negative electrode plate comprises a plate body and a negative electrode material coated on the plate body, and the negative electrode material is hard carbon negative electrode material according to the embodiment of the third aspect of the invention.
According to the battery provided by the embodiment of the invention, through the application of the hard carbon anode material, the oxygen element content in the oxygen-doped hard carbon material can be more reasonable, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of the battery using the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, thereby ensuring the first coulomb efficiency of the oxygen-doped hard carbon material.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic flow chart of a method of preparing an oxygen doped hard carbon material according to some embodiments of the present invention;
fig. 2 is a schematic diagram of a plasma ball milling apparatus according to some embodiments of the invention.
Reference numerals:
100. a plasma ball milling device;
10. a discharge electrode rod; 11. an insulating dielectric layer;
20. ball mill; 21. a ball milling tank; 22. ball milling cavity; 23. a ball mill body;
30. And a plasma power supply.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
A method of preparing an oxygen doped hard carbon material according to an embodiment of the present invention is described below with reference to fig. 1 to 2.
As shown in fig. 1-2, a method for preparing an oxygen doped hard carbon material according to an embodiment of the first aspect of the present invention includes the steps of:
hard carbon materials and grinding balls are put into the ball milling tank 21 of the plasma ball milling equipment 100, and the grinding balls can grind and crush the hard carbon materials, so that the granularity of the hard carbon materials is reduced conveniently;
introducing oxygen-containing gas into the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches a first preset value, wherein the introduced oxygen-containing gas is a main source of oxygen element in the ball milling tank 21, so that oxygen doping of the hard carbon material is realized;
the plasma ball milling apparatus 100 operates to ionize the oxygen-containing gas within the ball milling tank 21 and to move the ball milling tank 21 to form an oxygen-doped hard carbon material;
The oxygen-doped hard carbon material is separated from the grinding balls to obtain an oxygen-doped hard carbon material. For example, after the grinding balls and the formed oxygen-doped hard carbon material are removed from the plasma ball milling apparatus 100, they may be screened through a suitable mesh number screen to separate the oxygen-doped hard carbon material from the grinding balls.
Wherein, when the plasma ball milling device 100 works, the oxygen-containing gas in the ball milling tank 21 is ionized, so that oxygen-containing plasmas are formed in the ball milling tank 21, and meanwhile, the ball milling tank 21 is enabled to move, so that the hard carbon material in the ball milling tank 21 collides with and rubs against the grinding balls, the grinding and crushing effects of the grinding balls on the hard carbon material are realized, and the granularity of the hard carbon material is reduced. The grinding ball is used for grinding and crushing the hard carbon material, and meanwhile, plasmas containing oxygen elements are continuously mixed with the hard carbon material, so that the oxygen elements are introduced into the hard carbon material, and the oxygen doped hard carbon material with certain oxygen content is formed.
For example, the oxygen-containing gas may form a plasma containing oxygen atoms after ionization, and during mixing of the oxygen-containing plasma with the hard carbon material, the oxygen atoms may combine with the carbon atoms to form oxygen-containing functional groups, such that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material increases. The oxygen-containing functional groups can absorb and contain part of ions, so that the capacity of the oxygen-doped hard carbon material for ions can be improved along with the increase of the number of the oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material, and the rate capability of a battery using the oxygen-doped hard carbon material can be improved.
Through the preparation method, on one hand, more oxygen elements can be introduced into the hard carbon material, and the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, so that the specific capacity of the oxygen-doped hard carbon material can be improved, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved.
On the other hand, when the ball milling tank 21 moves, the grinding balls can grind the hard carbon material, so that the granularity of the oxygen doped hard carbon material is smaller, and when the oxygen doped hard carbon material is used as the negative electrode material of the battery, the diffusion path of ions can be shortened, and the multiplying power performance of the oxygen doped hard carbon material is improved; and the granularity of the oxygen-doped hard carbon material is reduced by grinding, so that the number of defects on the surface of the oxygen-doped hard carbon material is increased, and the defects on the surface of the oxygen-doped hard carbon material can accommodate part of ions, therefore, along with the increase of the number of defects on the surface of the oxygen-doped hard carbon material, the specific capacity of the oxygen-doped hard carbon material is also improved, and the rate capability of a battery applying the oxygen-doped hard carbon material can be improved.
According to the preparation method of the oxygen-doped hard carbon material, more oxygen elements can be introduced into the hard carbon material through the preparation method, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, the specific capacity of the oxygen-doped hard carbon material can be improved, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved; in addition, the preparation method can lead the granularity of the oxygen-doped hard carbon material to be smaller, shorten the diffusion path of ions, improve the rate capability of the battery applying the oxygen-doped hard carbon material, increase the surface defects of the oxygen-doped hard carbon material, and improve the specific capacity of the oxygen-doped hard carbon material, thereby further improving the rate capability of the battery applying the oxygen-doped hard carbon material.
According to some embodiments of the invention, the grinding ball is made of stainless steel or cemented carbide. On one hand, the stainless steel or the hard alloy has the advantages of higher hardness, better wear resistance, heat resistance, corrosion resistance and the like, and the excellent properties can prolong the service life of the grinding ball and ensure the grinding effect of the grinding ball on hard carbon materials; on the other hand, stainless steel or cemented carbide has conductivity, which facilitates ionization of the oxygen-containing gas by the plasma ball milling apparatus 100, and facilitates formation of plasma in the ball milling tank 21.
According to some embodiments of the invention, the mass ratio of the grinding balls to the hard carbon material is 5:1 to 50:1. If the mass ratio of the grinding balls to the hard carbon material is too large, the idle work loss of impact friction formed between the grinding balls and the ball milling tank 21 is large, the overall consumed power is large, and the service life of the grinding balls is reduced; if the mass ratio of the grinding ball to the hard carbon material is too small, the hard carbon material can generate a buffer effect on the impact and friction of the grinding ball, so that the grinding and crushing effect of the grinding ball on the hard carbon material is reduced.
Therefore, the mass ratio of the grinding ball to the hard carbon material is in the range of 5:1-50:1, the overall consumed power is less, the service life of the grinding ball is prolonged, the grinding and crushing effect of the grinding ball on the hard carbon material can be ensured, and the granularity of the hard carbon material after grinding meets the requirement.
For example, the mass ratio of the grinding ball to the hard carbon material can be 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 40:1, 50:1, etc., wherein when the mass ratio of the grinding ball to the hard carbon material is 10:1, the grinding effect of the grinding ball on the hard carbon material can be better ensured, the granularity of the hard carbon material after grinding meets the requirement, meanwhile, the power consumption of the whole grinding ball is less, and the service life of the grinding ball is prolonged.
According to some embodiments of the invention, the grinding balls comprise first and second grinding balls of different diameters, the ratio of the diameters of the first and second grinding balls being in the range of 1.5 to 3.5, and the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball being in the range of 0.8 to 1.2. The arrangement can lead the diameter of the first grinding ball to be larger than that of the second grinding ball, the mass arrangement of the first grinding ball and the second grinding ball is reasonable, when the ball milling tank 21 just starts to move, the granularity of the hard carbon material is larger, and compared with the second grinding ball with smaller diameter, the first grinding ball with larger diameter can grind and crush the hard carbon material better; with the movement of the ball milling tank 21, the granularity of the hard carbon material is continuously reduced, when the granularity of the hard carbon material is smaller, compared with the first grinding ball with larger diameter, the second grinding ball with smaller diameter has better grinding and crushing effect on the hard carbon material, and finally, the granularity of the hard carbon material meets the requirement. Therefore, in the whole movement process of the ball milling tank 21, the grinding effect of the grinding balls on the hard carbon material can be ensured, and the grinding efficiency of the whole hard carbon material is improved.
For example, the ratio of the diameters of the first and second grinding balls may take on values of 1.5, 2, 2.5, 3.5, etc., and the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball may take on values of 0.8, 1.0, 1.2, etc. When the diameter ratio of the first grinding ball to the second grinding ball is 2.5, and the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, the grinding effect of the grinding balls on the hard carbon material can be better ensured, and the grinding efficiency of the whole hard carbon material is improved.
According to some embodiments of the invention, the first grinding balls have a diameter in the range of 2-8 mm and the second grinding balls have a diameter in the range of 1-3 mm. When the ball milling tank 21 moves, the first grinding balls and the second grinding balls are matched with each other, so that the grinding and crushing effects of the whole on the hard carbon materials can be ensured, and the crushing efficiency of the whole on the hard carbon materials can be improved.
For example, the diameter of the first grinding ball may take the value of 2mm, 4mm, 5mm, 8mm, etc., and the diameter of the second grinding ball may take the value of 1mm, 2mm, 3mm, etc. When the diameter value of the first grinding ball is 5mm, and the diameter value of the second grinding ball is 2mm, the grinding effect of the grinding ball on the hard carbon material can be better ensured, and the grinding efficiency of the whole grinding ball on the hard carbon material is improved.
According to some embodiments of the present invention, before introducing the oxygen-containing gas into the ball mill tank 21 and after placing the hard carbon material and the grinding balls into the ball mill tank 21, the ball mill tank 21 is vacuumized until the air pressure in the ball mill tank 21 reaches a second preset value, which is smaller than the first preset value. From this, before letting in the oxygen-containing gas to ball-milling jar 21, can be through the original impurity gas discharge in with ball-milling jar 21 of evacuation for when wholly carrying out ionization to the oxygen-containing gas, the air in the ball-milling jar 21 is the oxygen-containing gas, thereby can avoid other impurity elements in the air to take place the reaction with oxygen element when ionization, and then can guarantee the oxygen content that introduces in the oxygen doping hard carbon material, can avoid other impurity elements to introduce the hard carbon material simultaneously, reduce the influence of impurity element to oxygen doping hard carbon material.
According to some embodiments of the present invention, the second preset value ranges from 0.0001 to 0.001 and Pa, so that the impurity gas in the ball milling tank 21 can reach a lower level, the influence of the impurity gas on the oxygen element is reduced, the oxygen content introduced into the oxygen-doped hard carbon material is ensured, and meanwhile, the influence of other impurity elements on the performance of the oxygen-doped hard carbon material can be avoided. For example, the second preset value may be 0.001Pa, 0.0008Pa, 0.0006Pa, 0.0004Pa, 0.0001 Pa, etc., for example, when the second preset value is 0.001Pa, the influence of the impurity gas on the oxygen element and the hard carbon material may be reduced better, so as to ensure the oxygen content introduced in the oxygen doped hard carbon material.
According to some embodiments of the invention, the oxygen-containing gas comprises oxygen. When oxygen is ionized, a plasma containing more oxygen elements can be generated, so that more oxygen elements can be conveniently introduced into the oxygen-doped hard carbon material.
According to some embodiments of the invention, the oxygen-containing gas comprises an argon-oxygen mixture. The argon-oxygen mixed gas is a mixed gas of argon and oxygen, so that the mixed gas of the argon and the oxygen can ionize oxygen to form oxygen-containing plasmas more easily in the same electric field environment, thereby reducing the ionization difficulty of the whole oxygen-containing gas and reducing the energy consumption of the plasma ball milling equipment 100.
According to some embodiments of the invention, the first preset value ranges from 10000 to 100000Pa. If the first preset value is too large, it means that too much oxygen-containing gas in the ball milling tank 21 can cause that the current in the electric field is not easy to break down the oxygen-containing gas, so that the overall ionization difficulty is high; if the first preset value is too small, it means that the oxygen-containing gas in the ball mill tank 21 is too small, resulting in less oxygen element in the ball mill tank 21.
On the one hand, the ball milling tank 21 can be ensured to contain more oxygen elements; on the other hand, the ionization difficulty of the whole oxygen-containing gas can be reduced, so that the ionization efficiency of the whole oxygen-containing gas is ensured. Therefore, the argon-oxygen mixture gas can generate more oxygen elements during ionization, so that the oxygen content introduced into the oxygen-doped hard carbon material can be improved.
For example, the first preset value can be 10000Pa, 50000Pa, 80000Pa, 100000Pa, etc., when the first preset value is 80000Pa, the ionization difficulty of the whole oxygen-containing gas can be better reduced, so that more oxygen elements can be generated when the argon-oxygen mixture is ionized, and the oxygen content introduced in the oxygen-doped hard carbon material is improved.
According to some embodiments of the invention, the hard carbon material has a particle size volume distribution of: the Dv50=12-18 um, so that the ball milling efficiency of the plasma ball milling equipment 100 on hard carbon materials can be ensured, and the ball milling time of the whole machine can be shortened.
According to some embodiments of the present invention, referring to fig. 2, a plasma ball milling apparatus 100 includes a discharge electrode rod 10 and a ball mill 20, a ball mill 21 is provided to the ball mill 20, the ball mill 20 is used to move the ball mill 21, the discharge electrode rod 10 is provided to the ball mill 21, and a ball milling chamber 22 for accommodating hard carbon materials and grinding balls is defined between the discharge electrode rod 10 and the ball mill 21. When the plasma ball milling device 100 works, the ball mill 20 drives the ball milling tank 21 to move, and the movement of the ball milling tank 21 drives the hard carbon material and the grinding balls in the ball milling cavity 22 to move, so that impact and friction are generated between the grinding balls and the hard carbon material, and the hard carbon material is ground and crushed.
In the process of installation, the hard carbon material and the grinding balls can be firstly filled into the ball milling cavity 22, and then the discharge electrode rod 10 is installed to the ball milling tank 21, so that the discharge electrode rod 10 can be conveniently fixed, and the sealing treatment of the ball milling tank 21 can be conveniently realized.
Wherein the plasma ball milling apparatus 100 includes a plasma power source 30, the discharge electrode rod 10 is adapted to be connected to an anode of the plasma power source 30, and the ball milling tank 21 is adapted to be connected to a cathode of the plasma power source 30 to form an electric field between the ball milling tank 21 and the discharge electrode rod 10. When a discharge phenomenon occurs in the electric field, the oxygen-containing gas in the ball mill tank 21 may be ionized to form a plasma having an oxygen-containing element. Along with the movement of the ball milling tank 21, the plasma is continuously mixed with the hard carbon material, so that a certain oxygen content is introduced into the hard carbon material to form the oxygen doped hard carbon material.
For example, the discharge electrode rod 10 may be a dielectric barrier discharge electrode rod 10, the outer peripheral wall of the discharge electrode rod 10 is coated with an insulating dielectric layer 11, the discharge electrode rod 10 is affected by the insulating dielectric layer 11, when the hard carbon material and the grinding balls are close to the discharge electrode rod 10, electric current can flow between the ball milling tank 21 and the discharge electrode rod 10 by utilizing the conductivity of the hard carbon material and the grinding balls, so that the discharge electrode rod 10 generates a discharge phenomenon, meanwhile, the movement of the ball milling tank 21 enables the hard carbon material and the grinding balls to move continuously, so that the current flow paths between the ball milling tank 21 and the discharge electrode rod 10 are intermittently communicated, thereby enabling the discharge electrode rod 10 to perform intermittent discharge, further avoiding the problem of overhigh temperature in the ball milling tank 21 caused by continuous discharge, ensuring the oxygen content introduced in the oxygen doped hard carbon material, and improving the number of oxygen-containing functional groups on the surface of the oxygen doped hard carbon material.
For example, when the plasma ball mill 100 is operated, the plasma power supply 30 may be turned on first, and then the ball mill 20 may be started.
According to some embodiments of the invention, the parameters of the electric field include: the discharge voltage is 10-30 kV, the discharge frequency is 7-12 kHz, and the discharge current is 1-3A. The arrangement can enable plasmas containing oxygen elements to be easily ionized in an electric field, and improves ionization efficiency; meanwhile, the excessive temperature in the ball milling tank 21 can be avoided, so that the oxygen content introduced in the oxygen-doped hard carbon material can be ensured, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved.
For example, the discharge voltage may be 10kV, 20kV, 30kV, etc., the discharge frequency may be 7 kHz, 8 kHz, 10kHz, 12kHz, etc., and the discharge current may be 1A, 1.5A, 3A, etc. When the discharge voltage is 20kV, the discharge frequency is 10kHz and the discharge current is 1.5A, plasmas containing oxygen elements can be ionized more easily in an electric field, and the ionization efficiency is improved; meanwhile, the excessive temperature in the ball milling tank 21 can be better avoided, so that the oxygen content introduced in the oxygen-doped hard carbon material can be better ensured, and the rate capability of a battery applying the oxygen-doped hard carbon material can be improved.
According to some embodiments of the present invention, referring to fig. 2, the ball mill 20 includes a ball mill body 23 and a motor rotatably coupled to the ball mill body 23 to drive the ball mill body 23 to vibrate, and the ball mill tank 21 is provided to the ball mill body 23. When the motor works, the rotation of the motor shaft can drive the ball mill body 23 to vibrate, and the vibration of the ball mill body 23 drives the ball mill tank 21 to vibrate, so that impact and friction are generated between the hard carbon material in the ball mill tank 21 and the grinding balls, and the overall grinding and crushing effect of the hard carbon material is realized. The motor rotation speed can influence the vibration amplitude, and the larger the motor rotation speed is, the larger the vibration amplitude of the ball milling tank 21 is, and the smaller the motor rotation speed is, the smaller the vibration amplitude of the ball milling tank 21 is.
The rotation speed of the motor is 1000-1500 rpm, the vibration amplitude of the ball milling tank 21 is 7-10 mm, and the ball milling time is 1-10 h. If the rotation speed of the motor is too high, the vibration amplitude of the ball milling tank 21 is too large and the ball milling time is too long, the granularity of the oxygen-doped hard carbon material is too small, so that the oxygen-doped hard carbon material is not easy to stir in the pulping process, and the overall processing difficulty is high; if the rotation speed of the motor is too slow, the vibration amplitude of the ball milling tank 21 is too small and the ball milling time is too short, so that the granularity of the oxygen-doped hard carbon material is too large, the diffusion path of ions in the oxygen-doped hard carbon material is too long, the rate capability of a battery applying the oxygen-doped hard carbon material is poor, the requirements of rate capability and quick charging capability cannot be met, fewer defects are caused on the surface, and the specific capacity of the oxygen-doped hard carbon material is low.
Thus, the arrangement can avoid the phenomenon that the granularity of the oxygen doped hard carbon material is too large or too small, so that the granularity of the oxygen doped hard carbon material is within the required range. On the one hand, the oxygen-doped hard carbon material is smaller, the diffusion path of ions in the oxygen-doped hard carbon material is shortened, the rate capability of a battery applying the oxygen-doped hard carbon material is improved, meanwhile, the defects on the surface of the oxygen-doped hard carbon material are more, the specific capacity of the oxygen-doped hard carbon material is improved, and the rate capability of the battery applying the oxygen-doped hard carbon material is improved. On the other hand, the processing difficulty of the oxygen doped hard carbon material in the pulping process can be reduced.
For example, the rotation speed of the motor may be 1000 rpm, 1200 rpm, 1400 rpm, 1500rpm, etc., the vibration amplitude of the ball mill 21 may be 5mm, 6mm, 8mm, 10mm, etc., and the ball milling time may be 1h, 4h, 6h, 8h, 10h, etc. When the rotation speed of the motor is 1200 rpm, the vibration amplitude of the ball milling tank 21 is 8mm and the ball milling time is 6h, the granularity of the oxygen-doped hard carbon material can be better ensured to be in a required range, so that the multiplying power performance of a battery applying the oxygen-doped hard carbon material can be improved, and the processing difficulty of the oxygen-doped hard carbon material in the pulping process can be better reduced.
According to an embodiment of the second aspect of the present invention, the oxygen-doped hard carbon material is prepared by the preparation method according to the embodiment of the first aspect of the present invention.
According to the oxygen-doped hard carbon material provided by the embodiment of the invention, more oxygen elements can be introduced into the hard carbon material by the preparation method, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is increased, the specific capacity of the oxygen-doped hard carbon material can be improved, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved; in addition, the preparation method can lead the granularity of the oxygen-doped hard carbon material to be smaller, shorten the diffusion path of ions, improve the rate capability of the battery applying the oxygen-doped hard carbon material, increase the surface defects of the oxygen-doped hard carbon material, and improve the specific capacity of the oxygen-doped hard carbon material, thereby further improving the rate capability of the battery applying the oxygen-doped hard carbon material.
According to some embodiments of the invention, the mass percentage of oxygen element in the oxygen doped hard carbon material is 0.05% -1.0%. If the mass percentage value of the oxygen element in the oxygen-doped hard carbon material is too small, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is too small, so that the specific capacity of the oxygen-doped hard carbon material is smaller, and the rate capability of a battery applying the oxygen-doped hard carbon material is lower.
If the mass percentage of the oxygen element in the oxygen-doped hard carbon material is too large, the excessive number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material can be caused, and when the oxygen-doped hard carbon material is used as a negative electrode material of a battery, partial ions contained in the oxygen-containing functional groups can not be normally removed, so that the reversible capacity of the oxygen-doped hard carbon material is lower, and the first coulomb efficiency of the oxygen-doped hard carbon material is lower.
Therefore, the oxygen element in the oxygen-doped hard carbon material has the mass percentage value range of 0.05% -1.0%, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is large, and the specific capacity of the oxygen-doped hard carbon material is improved, so that the rate capability of a battery applying the oxygen-doped hard carbon material is improved, the reversible capacity of the oxygen-doped hard carbon material can be ensured, and the first coulomb efficiency of the oxygen-doped hard carbon material is ensured.
According to some embodiments of the invention, the particle size volume distribution of the oxygen doped hard carbon material satisfies: dv50=3 to 8um. If the value of the Dv50 of the particle size volume distribution is too large, the particle size of the oxygen-doped hard carbon material is too large, so that the diffusion path of ions is longer, and the rate capability of a battery applying the oxygen-doped hard carbon material is poorer; if the value of the Dv50 of the particle size volume distribution is too small, the processing difficulty of the oxygen doped hard carbon material in the pulping process is high.
Therefore, on one hand, the granularity of the oxygen-doped hard carbon material is smaller, so that the diffusion path of ions can be shortened, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved; on the other hand, the processing difficulty of the oxygen doped hard carbon material in the pulping process can be reduced.
According to some embodiments of the invention, the particle size number distribution of the oxygen doped hard carbon material satisfies: dn10=0.2 to 0.7um, dn50=0.5 to 1.5um. Therefore, the oxygen-doped hard carbon material can contain more particles with smaller granularity, so that the diffusion path of ions can be shortened, the rate capability of a battery applying the oxygen-doped hard carbon material is improved, and the processing difficulty of the oxygen-doped hard carbon material in the pulping process can be reduced.
According to some embodiments of the invention, the oxygen-doped hard carbon material has a specific surface area of 2 to 6 m 2 And/g. If the specific surface area of the oxygen-doped hard carbon material is too small, the particle size of the oxygen-doped hard carbon material is too large, so that the contact area between the oxygen-doped hard carbon material and electrolyte is too small when the oxygen-doped hard carbon material is applied to a battery, the internal resistance of the oxygen-doped hard carbon material is too large, the ion diffusion path is too long, and the rate capability of the battery using the oxygen-doped hard carbon material is poor.
If the specific surface area of the oxygen-doped hard carbon material is too large, the particle size of the oxygen-doped hard carbon material is too small, so that the contact area between the oxygen-doped hard carbon material and the electrolyte is too large when the oxygen-doped hard carbon material is applied to a battery, the processing difficulty of the oxygen-doped hard carbon material in the pulping process is large, and meanwhile, the side reaction generated at the interface between the oxygen-doped hard carbon material and the electrolyte when the oxygen-doped hard carbon material is applied to the battery is too large, so that the initial coulomb efficiency of the battery is low.
Thus, the specific surface area of the oxygen-doped hard carbon material is 2 to 6 m 2 On one hand, the diffusion path of ions can be shortened, and the application of the oxygen doped hard carbon material can be improvedRate capability of the battery; on the other hand, the processing difficulty of the oxygen-doped hard carbon material in the pulping process can be reduced, and meanwhile, when the oxygen-doped hard carbon material is applied to a battery, the first coulomb efficiency of the battery is ensured.
According to the oxygen-doped hard carbon material of the embodiment of the third aspect of the invention, the mass percentage of oxygen element in the oxygen-doped hard carbon material is 0.05% -1.0%. If the mass percentage value of the oxygen element in the oxygen-doped hard carbon material is too small, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is too small, so that the specific capacity of the oxygen-doped hard carbon material is smaller, and the rate capability of a battery applying the oxygen-doped hard carbon material is lower.
If the mass percentage of the oxygen element in the oxygen-doped hard carbon material is too large, the excessive number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material can be caused, and when the oxygen-doped hard carbon material is used as a negative electrode material of a battery, partial ions contained in the oxygen-containing functional groups can not be normally removed, so that the reversible capacity of the oxygen-doped hard carbon material is lower, and the first coulomb efficiency of the oxygen-doped hard carbon material is lower.
Therefore, the oxygen element in the oxygen-doped hard carbon material has the mass percentage value range of 0.05% -1.0%, the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is large, and the specific capacity of the oxygen-doped hard carbon material is improved, so that the rate capability of a battery applying the oxygen-doped hard carbon material is improved, the reversible capacity of the oxygen-doped hard carbon material can be ensured, and the first coulomb efficiency of the oxygen-doped hard carbon material is ensured.
According to the oxygen-doped hard carbon material provided by the embodiment of the invention, the content of oxygen elements in the oxygen-doped hard carbon material can be more reasonable, and the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, so that the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of a battery applying the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, so that the first coulomb efficiency of the oxygen-doped hard carbon material is ensured.
According to some embodiments of the invention, the particle size volume distribution of the oxygen doped hard carbon material satisfies: dv50=3 to 8um. If the value of the Dv50 of the particle size volume distribution is too large, the particle size of the oxygen-doped hard carbon material is too large, so that the diffusion path of ions is longer, and the rate capability of a battery applying the oxygen-doped hard carbon material is poorer; if the value of the Dv50 of the particle size volume distribution is too small, the processing difficulty of the oxygen doped hard carbon material in the pulping process is high.
Therefore, on one hand, the granularity of the oxygen-doped hard carbon material is smaller, so that the diffusion path of ions can be shortened, and the rate capability of a battery applying the oxygen-doped hard carbon material is improved; on the other hand, the processing difficulty of the oxygen doped hard carbon material in the pulping process can be reduced.
According to some embodiments of the invention, the particle size number distribution of the oxygen doped hard carbon material satisfies: dn10=0.2 to 0.7um, dn50=0.5 to 1.5um. Therefore, the oxygen-doped hard carbon material can contain more particles with smaller granularity, so that the diffusion path of ions can be shortened, the rate capability of a battery applying the oxygen-doped hard carbon material is improved, and the processing difficulty of the oxygen-doped hard carbon material in the pulping process can be reduced.
According to some embodiments of the invention, the oxygen-doped hard carbon material has a specific surface area of 2 to 6 m 2 And/g. If the specific surface area of the oxygen-doped hard carbon material is too small, the particle size of the oxygen-doped hard carbon material is too large, so that the contact area between the oxygen-doped hard carbon material and electrolyte is too small when the oxygen-doped hard carbon material is applied to a battery, the internal resistance of the oxygen-doped hard carbon material is too large, the ion diffusion path is too long, and the rate capability of the battery using the oxygen-doped hard carbon material is poor.
If the specific surface area of the oxygen-doped hard carbon material is too large, the particle size of the oxygen-doped hard carbon material is too small, so that the contact area between the oxygen-doped hard carbon material and the electrolyte is too large when the oxygen-doped hard carbon material is applied to a battery, the processing difficulty of the oxygen-doped hard carbon material in the pulping process is large, and meanwhile, the side reaction generated at the interface between the oxygen-doped hard carbon material and the electrolyte when the oxygen-doped hard carbon material is applied to the battery is too large, so that the initial coulomb efficiency of the battery is low.
Thus, the specific surface area of the oxygen-doped hard carbon material is 2 to 6 m 2 On one hand, the diffusion path of ions can be shortened, and the oxygen doping can be promotedThe rate capability of the battery made of the heterohardening carbon material; on the other hand, the processing difficulty of the oxygen-doped hard carbon material in the pulping process can be reduced, and meanwhile, when the oxygen-doped hard carbon material is applied to a battery, the first coulomb efficiency of the battery is ensured.
According to some optional embodiments of the present invention, the oxygen-doped hard carbon material is prepared by the preparation method according to the above-mentioned first aspect of the present invention, so that the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of a battery using the oxygen-doped hard carbon material can be improved, and the reversible capacity of the oxygen-doped hard carbon material can be ensured, thereby ensuring the first coulomb efficiency of the oxygen-doped hard carbon material; in addition, the granularity of the oxygen-doped hard carbon material is smaller, the diffusion path of ions is shortened, and the surface defects of the oxygen-doped hard carbon material are more, so that the specific capacity of the oxygen-doped hard carbon material is improved, and the rate capability of a battery applying the oxygen-doped hard carbon material can be further improved.
A hard carbon anode material according to an embodiment of a fourth aspect of the present invention includes an oxygen doped hard carbon material according to an embodiment of the above second aspect of the present invention and an oxygen doped hard carbon material according to an embodiment of the above third aspect of the present invention.
According to the hard carbon negative electrode material provided by the embodiment of the invention, through the application of the oxygen-doped hard carbon material, the oxygen element content in the oxygen-doped hard carbon material can be more reasonable, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of a battery applying the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, thereby ensuring the first coulomb efficiency of the oxygen-doped hard carbon material; in addition, the granularity of the oxygen-doped hard carbon material is smaller, the diffusion path of ions is shortened, and the surface defects of the oxygen-doped hard carbon material are more, so that the specific capacity of the oxygen-doped hard carbon material is improved, and the rate capability of a battery applying the oxygen-doped hard carbon material can be further improved.
According to some embodiments of the invention, a negative electrode plate of a half battery is prepared by taking metal as a negative electrode material, a positive electrode plate of the half battery is prepared by taking hard carbon negative electrode material as a positive electrode material, and the negative electrode plate of the half battery and the positive electrode plate of the half battery are assembled into the half battery. For example, when the hard carbon negative electrode material is applied to a sodium ion battery, and the hard carbon negative electrode material is used as the negative electrode material of the sodium ion battery, the negative electrode material of the negative electrode piece of the half battery is sodium metal; when the hard carbon negative electrode material is applied to a lithium ion battery and is used as a negative electrode material of the lithium ion battery, the negative electrode material of the negative electrode plate of the half battery is metal lithium.
Wherein, the discharge capacity of the half cell is more than 0.1V and more than 32% of the total discharge capacity. In the process of changing from high potential to low potential, the total capacity of the half cell which can be discharged in the whole process is the total discharge capacity. Therefore, the discharge capacity of the half battery is more than 0.1V and more than 32% of the total discharge capacity, so that the half battery has better rate capability, and when the hard carbon negative electrode material is applied to the negative electrode material of the battery, the rate capability of the battery can be improved, and the overall performance of the battery can be further improved.
According to some embodiments of the invention, the half cell 0.1C discharge capacity accounts for more than 85% of the total discharge capacity. According to some characteristic factors of the half cell, the whole discharge capacity needs to be completely released in multiple stages, namely, under the condition of high current, the half cell can release part of the discharge capacity, then the current value is reduced, and the half cell can further release another part of the discharge capacity.
Therefore, the 0.1C discharge capacity of the half battery accounts for more than 85% of the total discharge capacity, so that the half battery has better rate capability, and the charge and discharge time of the half battery is shortened, thereby improving the rate capability of the battery, shortening the charge and discharge time of the battery and further improving the overall performance of the battery when the hard carbon negative electrode material is applied to the negative electrode material of the battery.
A battery according to an embodiment of a fifth aspect of the present invention includes: a housing and an electrode assembly.
The electrode assembly is arranged in the shell, and comprises a negative electrode plate and a positive electrode plate, wherein the negative electrode plate comprises a plate body and a negative electrode material coated on the plate body, and the negative electrode material is a hard carbon negative electrode material according to the fourth embodiment of the invention.
When the battery is charged, the metal positive ions of the positive electrode plate can be separated under the action of potential and move towards the negative electrode plate, and finally the positive ions are inserted into the negative electrode material, and meanwhile, the electrons of the positive electrode plate can also move from an external circuit to the negative electrode plate; when the battery is discharged, metal positive ions inserted into the negative electrode material in the charging process are separated from the negative electrode material and move towards the positive electrode plate, and finally are inserted into the positive electrode material, and meanwhile, electrons of the negative electrode plate also move from an external circuit to the positive electrode plate.
The anode material is the hard carbon anode material according to the fourth aspect of the present invention, on one hand, the anode material can contain more oxygen elements, so that the number of oxygen-containing functional groups on the surface of the anode material is increased, thereby improving the specific capacity of the anode material, improving the rate capability of the anode material, and simultaneously ensuring the reversible capacity of the anode material, thereby ensuring the first coulomb efficiency of the anode material; on the other hand, the granularity of the anode material is smaller, the diffusion path of ions is shortened, and meanwhile, the surface defects of the anode material are more, so that the specific capacity of the oxygen-doped hard carbon material can be improved, and the rate capability of the oxygen-doped hard carbon material can be further improved. In addition, with the improvement of the multiplying power performance of the anode material, the phenomenon that simple substance metal is separated out of the surface of the anode material can be improved, so that the safety performance of the battery can be improved.
According to the battery provided by the embodiment of the invention, through the application of the hard carbon negative electrode material, the oxygen element content in the oxygen-doped hard carbon material can be more reasonable, so that the number of oxygen-containing functional groups on the surface of the oxygen-doped hard carbon material is more reasonable, the specific capacity of the oxygen-doped hard carbon material can be improved, the rate capability of the battery applying the oxygen-doped hard carbon material can be improved, and meanwhile, the reversible capacity of the oxygen-doped hard carbon material can be ensured, and the first coulomb efficiency of the oxygen-doped hard carbon material can be ensured; in addition, the granularity of the oxygen-doped hard carbon material is smaller, the diffusion path of ions is shortened, and the surface defects of the oxygen-doped hard carbon material are more, so that the specific capacity of the oxygen-doped hard carbon material is improved, and the rate capability of a battery applying the oxygen-doped hard carbon material can be further improved.
According to some embodiments of the invention, the battery is a sodium ion battery. Compared with other types of batteries in the related art, the sodium ion battery has the advantages of low cost of raw materials, good low-temperature performance, short charging time and the like.
The embodiments of the present invention will be further described with reference to a plurality of embodiments and a comparative example, wherein the first to fifth embodiments are the plurality of embodiments of the present invention, and the first to third comparative examples are comparative examples with the plurality of embodiments of the present invention.
In a first embodiment of the present invention,
a method for preparing an oxygen doped hard carbon material, comprising:
firstly, loading 30g of hard carbon material, a first grinding ball with the diameter of 5mm and a second grinding ball with the diameter of 2mm into a ball milling tank 21, wherein the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, and the mass ratio of the grinding ball to the hard carbon material is 10:1; the discharge electrode rod 10 was then installed at the center of the ball mill 21, and then the ball mill 21 was sealed.
And secondly, vacuumizing the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches the ball milling tank 21, wherein the second preset value is 0.001Pa, and then introducing an argon-oxygen mixed gas with the mass ratio of 5% of oxygen to argon-oxygen mixed gas until the air pressure in the ball milling tank 21 reaches the first preset value, wherein the first preset value is 50000Pa.
Third, the discharge electrode rod 10 was connected to the positive electrode of the plasma power supply 30, the ball mill tank 21 was connected to the negative electrode of the plasma power supply 30, and then the plasma power supply 30 was turned on to form an electric field in which the discharge voltage was set to 20kV, the discharge frequency was set to 10kHz, and the discharge current was set to 1.5A.
Fourth, the rotation speed of the motor is set to 1200rpm, the vibration amplitude of the ball milling tank 21 is 8mm, the ball mill 20 is started, and the ball milling time is 6h.
And fifthly, separating the oxygen doped hard carbon material from the grinding balls to obtain the oxygen doped hard carbon material.
In a second embodiment of the present invention,
a method for preparing an oxygen doped hard carbon material, comprising:
firstly, loading 30g of hard carbon material, a first grinding ball with the diameter of 5mm and a second grinding ball with the diameter of 2mm into a ball milling tank 21, wherein the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, and the mass ratio of the grinding ball to the hard carbon material is 5:1; the discharge electrode rod 10 was then installed at the center of the ball mill 21, and then the ball mill 21 was sealed.
And secondly, vacuumizing the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches a second preset value, wherein the second preset value is 0.001Pa, and then introducing an argon-oxygen mixed gas with the mass ratio of oxygen to the argon-oxygen mixed gas of 5% until the air pressure in the ball milling tank 21 reaches a first preset value, wherein the first preset value is 50000Pa.
Third, the discharge electrode rod 10 was connected to the positive electrode of the plasma power supply 30, the ball mill tank 21 was connected to the negative electrode of the plasma power supply 30, and then the plasma power supply 30 was turned on to form an electric field in which the discharge voltage was set to 20kV, the discharge frequency was set to 10kHz, and the discharge current was set to 1.5A.
Fourth, the rotation speed of the motor is set to 1200rpm, the vibration amplitude of the ball milling tank 21 is 8mm, the ball mill 20 is started, and the ball milling time is 6h.
And fifthly, separating the oxygen doped hard carbon material from the grinding balls to obtain the oxygen doped hard carbon material.
In a third embodiment of the present invention,
a method for preparing an oxygen doped hard carbon material, comprising:
firstly, loading 30g of hard carbon material, a first grinding ball with the diameter of 5mm and a second grinding ball with the diameter of 2mm into a ball milling tank 21, wherein the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, and the mass ratio of the grinding ball to the hard carbon material is 10:1; the discharge electrode rod 10 was then installed at the center of the ball mill 21, and then the ball mill 21 was sealed.
And secondly, vacuumizing the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches a second preset value, wherein the second preset value is 0.001Pa, and then introducing an argon-oxygen mixed gas with the mass ratio of oxygen to the argon-oxygen mixed gas of 5% until the air pressure in the ball milling tank 21 reaches a first preset value, wherein the first preset value is 30000Pa.
Third, the discharge electrode rod 10 was connected to the positive electrode of the plasma power supply 30, the ball mill tank 21 was connected to the negative electrode of the plasma power supply 30, and then the plasma power supply 30 was turned on to form an electric field in which the discharge voltage was set to 20kV, the discharge frequency was set to 10kHz, and the discharge current was set to 1.5A.
Fourth, the rotation speed of the motor is set to 1200rpm, the vibration amplitude of the ball milling tank 21 is 8mm, the ball mill 20 is started, and the ball milling time is 6h.
And fifthly, separating the oxygen doped hard carbon material from the grinding balls to obtain the oxygen doped hard carbon material.
In a fourth embodiment of the present invention,
a method for preparing an oxygen doped hard carbon material, comprising:
firstly, loading 30g of hard carbon material, a first grinding ball with the diameter of 5mm and a second grinding ball with the diameter of 2mm into a ball milling tank 21, wherein the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, and the mass ratio of the grinding ball to the hard carbon material is 10:1; the discharge electrode rod 10 was then installed at the center of the ball mill 21, and then the ball mill 21 was sealed.
And secondly, vacuumizing the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches a second preset value, wherein the second preset value is 0.001Pa, and then introducing an argon-oxygen mixed gas with the mass ratio of oxygen to the argon-oxygen mixed gas of 5% until the air pressure in the ball milling tank 21 reaches a first preset value, wherein the first preset value is 50000Pa.
Third, the discharge electrode rod 10 was connected to the positive electrode of the plasma power supply 30, the ball mill tank 21 was connected to the negative electrode of the plasma power supply 30, and then the plasma power supply 30 was turned on to form an electric field in which the discharge voltage was set to 20kV, the discharge frequency was set to 10kHz, and the discharge current was set to 1.5A.
Fourth, the rotation speed of the motor is set to 1000rpm, the vibration amplitude of the ball milling tank 21 is 8mm, the ball mill 20 is started, and the ball milling time is 6h.
And fifthly, separating the oxygen doped hard carbon material from the grinding balls to obtain the oxygen doped hard carbon material.
In a fifth embodiment of the present invention,
a method for preparing an oxygen doped hard carbon material, comprising:
firstly, loading 30g of hard carbon material, a first grinding ball with the diameter of 5mm and a second grinding ball with the diameter of 2mm into a ball milling tank 21, wherein the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball is 1.0, and the mass ratio of the grinding ball to the hard carbon material is 10:1; the discharge electrode rod 10 was then installed at the center of the ball mill 21, and then the ball mill 21 was sealed.
And secondly, vacuumizing the ball milling tank 21 until the air pressure in the ball milling tank 21 reaches a second preset value, wherein the second preset value is 0.001Pa, and then introducing an argon-oxygen mixed gas with the mass ratio of oxygen to the argon-oxygen mixed gas of 5% until the air pressure in the ball milling tank 21 reaches a first preset value, wherein the first preset value is 50000Pa.
Third, the discharge electrode rod 10 was connected to the positive electrode of the plasma power supply 30, the ball mill tank 21 was connected to the negative electrode of the plasma power supply 30, and then the plasma power supply 30 was turned on to form an electric field in which the discharge voltage was set to 20kV, the discharge frequency was set to 10kHz, and the discharge current was set to 1.5A.
Fourth, the rotation speed of the motor is set to 1200rpm, the vibration amplitude of the ball milling tank 21 is 8mm, the ball mill 20 is started, and the ball milling time is 4 hours.
And fifthly, separating the oxygen doped hard carbon material from the grinding balls to obtain the oxygen doped hard carbon material.
In the first comparative example, the first,
the difference between the preparation method of the oxygen-doped hard carbon material provided in this comparative example and the preparation method of the oxygen-doped hard carbon material provided in example one is that: the mass ratio of the grinding balls to the hard carbon material in this example was 3:1.
In the second comparative example, the first comparative example,
the difference between the preparation method of the oxygen-doped hard carbon material provided in this comparative example and the preparation method of the oxygen-doped hard carbon material provided in example one is that: in this example, high purity argon was used as the oxygen-containing gas in place of the argon-oxygen mixture.
In the third comparative example, the first and second comparative examples,
the difference between the preparation method of the oxygen-doped hard carbon material provided in this comparative example and the preparation method of the oxygen-doped hard carbon material provided in example one is that: the rotational speed of the motor of ball mill 20 in this embodiment is 800rpm.
The values of the partial process parameters of examples one to five and comparative examples one to three are shown in Table 1.
TABLE 1
And manufacturing the oxygen doped hard carbon materials obtained in the first embodiment to the fifth embodiment and the comparative examples one to the third embodiment to form a negative electrode plate, assembling the obtained negative electrode plate into a half cell, and performing electrochemical performance test. The battery performance test results are shown in table 2.
TABLE 2
The test results show that compared with the comparative examples one to three, the batteries using the negative electrode materials provided by the examples one to five have higher oxygen content, larger 0.1C discharge capacity, larger discharge capacity than 0.1V, higher initial coulombic efficiency, and 0.1C discharge capacity accounting for more than 85% of the total discharge capacity, and the rate performance of the negative electrode materials is better; the discharge capacity of more than 0.1V accounts for more than 32% of the total discharge capacity, and the ion storage capacity of the anode material in the adsorption stage can be shown, and the capacity in the adsorption stage is higher, so that the rate capability of the anode material is better. Thus, the anode materials of examples one to five were described as having good rate performance.
And, the test results of the first to fifth embodiments can be obtained: in the mass percentage value range of 0.05% -1.0%, the higher the oxygen content of the anode material is, the larger the specific capacity of the anode material is, and the higher the discharge capacity, the charge capacity and the first coulombic efficiency of the anode material are. The smaller the particle size of the anode material is, the larger the specific surface area is, and the better the rate capability of the anode material is.
In addition, when the performance test is performed on the half cell, the ratio of the discharge capacity at a higher rate (i.e., the 0.5C discharge capacity) to the 0.1C discharge capacity is recorded, and the data indicate that the ratio of the 0.5C discharge capacity to the 0.1C discharge capacity in examples one to five is higher, which can further explain that the rate performance of the negative electrode materials in examples one to five is better.
In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (16)

1. A method for preparing an oxygen-doped hard carbon material, comprising:
putting hard carbon materials and grinding balls into a ball milling tank of plasma ball milling equipment;
introducing oxygen-containing gas into the ball milling tank until the air pressure in the ball milling tank reaches a first preset value;
the plasma ball milling device operates to ionize an oxygen-containing gas within the ball milling tank and to move the ball milling tank to form an oxygen-doped hard carbon material;
separating the oxygen-doped hard carbon material from the grinding balls to obtain the oxygen-doped hard carbon material.
2. The method for preparing an oxygen-doped hard carbon material according to claim 1, wherein the mass ratio of the grinding balls to the hard carbon material is 5:1-50:1; and/or the grinding balls comprise a first grinding ball and a second grinding ball with different diameters, the diameter ratio of the first grinding ball to the second grinding ball ranges from 1.5 to 3.5, and the ratio of the total mass of the first grinding ball to the total mass of the second grinding ball ranges from 0.8 to 1.2.
3. The method for producing an oxygen-doped hard carbon material according to claim 1, wherein before introducing an oxygen-containing gas into the ball mill tank and after placing a hard carbon material and a grinding ball into the ball mill tank, the ball mill tank is vacuumized until the air pressure in the ball mill tank reaches a second preset value, the second preset value being smaller than the first preset value;
Wherein the second preset value ranges from 0.0001 to 0.001 and Pa.
4. The method of producing an oxygen-doped hard carbon material according to claim 1, wherein the oxygen-containing gas includes oxygen.
5. The method of producing an oxygen-doped hard carbon material according to claim 4, wherein the oxygen-containing gas comprises an argon-oxygen mixture.
6. The method for preparing an oxygen-doped hard carbon material according to claim 1, wherein the first preset value ranges from 10000 to 100000Pa; and/or, the hard carbon material has a particle size volume distribution of: dv50=12 to 18um.
7. The method for preparing oxygen-doped hard carbon material according to claim 1, wherein the plasma ball milling device comprises a discharge electrode rod and a ball mill, the ball mill is arranged on the ball mill, the ball mill is used for driving the ball mill to move, and the discharge electrode rod is arranged on the ball mill and defines a ball milling cavity with the ball mill to contain the hard carbon material and the grinding balls;
the plasma ball milling equipment comprises a plasma power supply, the discharge electrode rod is suitable for being connected with the positive electrode of the plasma power supply, and the ball milling tank is suitable for being connected with the negative electrode of the plasma power supply so as to form an electric field between the ball milling tank and the discharge electrode rod.
8. The method of claim 7, wherein the parameters of the electric field include: the discharge voltage is 10-30 kV, the discharge frequency is 7-12 kHz, and the discharge current is 1-3A.
9. The method for preparing an oxygen-doped hard carbon material according to claim 7, wherein the ball mill comprises a ball mill body and a motor, the motor is rotatably connected with the ball mill body to drive the ball mill body to vibrate, the ball mill tank is arranged on the ball mill body, the rotating speed of the motor is 1000-1500 rpm, the vibration amplitude of the ball mill tank is 7-10 mm, and the ball milling time is 1-10 h.
10. The oxygen-doped hard carbon material is characterized in that the mass percentage of oxygen element in the oxygen-doped hard carbon material is 0.05% -1.0%.
11. The oxygen-doped hard carbon material according to claim 10, wherein the oxygen-doped hard carbon material has a particle size volume distribution that satisfies: dv50=3 to 8um; and/or, the particle size number distribution of the oxygen doped hard carbon material satisfies: dn10=0.2 to 0.7um, dn50=0.5 to 1.5um.
12. The oxygen-doped hard carbon material according to claim 10, wherein the oxygen-doped hard carbon material has a specific surface area of 2 to 6 m 2 /g。
13. The oxygen-doped hard carbon material according to any one of claims 10 to 12, wherein the oxygen-doped hard carbon material is prepared by the method for preparing an oxygen-doped hard carbon material according to any one of claims 1 to 9.
14. A hard carbon anode material comprising the oxygen-doped hard carbon material according to any one of claims 10 to 13.
15. The hard carbon negative electrode material according to claim 14, wherein a negative electrode plate of a half cell is prepared by taking metal as a negative electrode material, a positive electrode plate of a half cell is prepared by taking the hard carbon negative electrode material as a positive electrode material, and the negative electrode plate of the half cell and the positive electrode plate of the half cell are assembled into the half cell;
wherein the half-cell has a discharge capacity of more than 0.1V and accounts for more than 32% of the total discharge capacity; and/or, the 0.1C discharge capacity of the half cell accounts for more than 85% of the total discharge capacity.
16. A battery, comprising:
a housing;
the electrode assembly is arranged in the shell and comprises a negative electrode plate and a positive electrode plate, the negative electrode plate comprises a plate body and a negative electrode material coated on the plate body, and the negative electrode material is a hard carbon negative electrode material according to any one of claims 14-15.
CN202310909851.7A 2023-07-24 2023-07-24 Oxygen-doped hard carbon material, preparation method thereof, hard carbon negative electrode material and battery Pending CN116621160A (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104549658A (en) * 2014-12-24 2015-04-29 华南理工大学 Application method of cold field plasma discharge assisted high energy ball milled powder and plasma assisted high energy ball milling device
CN113363468A (en) * 2021-06-24 2021-09-07 西北工业大学 Modified hard carbon and modification method and application thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104549658A (en) * 2014-12-24 2015-04-29 华南理工大学 Application method of cold field plasma discharge assisted high energy ball milled powder and plasma assisted high energy ball milling device
CN113363468A (en) * 2021-06-24 2021-09-07 西北工业大学 Modified hard carbon and modification method and application thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHAO SHEN ET AL.: ""Tailoring the Surface Chemistry of Hard Carbon Towards High-Efficiency Sodium Ion Storage"", 《NANOSCALE》, pages 8959 - 8966 *
ZHIMENG SHEN ET AL.: ""Mechanochemistry assisted surface chemical modification on hard carbon for sodium storage: Size effect"", 《APPLIED SURFACE SCIENCE》, pages 154931 *

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