CN102867945B - Preparation method of graphite negative electrode material containing hollow carbon nanostructure for lithium ion battery - Google Patents

Abstract

A preparation method of lithium-ion battery graphite negative electrode material containing hollow carbon nanostructures is the first explosion method to prepare nano-metal particle-doped pitch: nano-metal particle-doped pitch is crushed to obtain powdered pitch with a particle size of 60-300 mesh , use powdered pitch as binder, natural graphite as aggregate, mix the two evenly by ball milling or mechanical stirring, and use hot pressing and sintering to obtain lithium-ion battery graphite negative electrode materials containing hollow carbon nanostructures. The catalyst of the invention has the advantages of high lithium storage capacity, high coulombic efficiency, good cycle performance, good rate performance and low cost.

Description

Preparation method of lithium-ion battery graphite negative electrode material containing hollow carbon nanostructure

technical field

The invention relates to a preparation method of a lithium ion battery negative electrode material, in particular to a preparation method of a lithium ion battery graphite negative electrode material containing a hollow carbon nanostructure. the

Background technique

Lithium-ion batteries are rapidly popularized in the field of electronic products such as mobile phones, cameras, and laptop lights due to their high energy density, long cycle life, and no memory effect, and have made some progress in power tools, electric bicycles, and electric vehicles. However, with the continuous development of society, people have higher requirements and expectations for lithium-ion batteries, hoping for larger capacity, higher Coulombic efficiency, better rate performance, and longer life. The improvement of battery performance depends on the development and improvement of electrode materials. Therefore, for a long time, improving the specific capacity of lithium-ion battery anode materials, reducing the first irreversible capacity, improving Coulombic efficiency, increasing rate performance, and improving cycle safety performance have always been the focus of anode material research. the

Among all lithium-ion battery anode materials, natural graphite has a lower discharge platform, and its cost is low and its resources are abundant. However, its structure is a layered structure, which is easy to cause the co-insertion of solvent molecules, so that the layers are peeled off during the charging and discharging process, resulting in poor cycle performance and poor safety performance of the battery. The modified natural graphite obtained by using different modification methods on the basis of natural graphite has greatly improved solvent compatibility and cycle safety performance, and is currently the product with the largest market share. At present, the main modification methods include spheroidization treatment, oxidation modification, fluorination modification, surface chemical treatment, surface coating, etc. Due to the limitation of the layered structure of graphite itself, the theoretical capacity is only 372mAh/g. Although it has been modified, it still cannot meet the needs of the future. Artificial graphite has good solvent compatibility, good cycle and rate performance, but because its specific capacity has not been greatly improved, and its preparation cost is high, there is no great advantage, and its market share is not high. For example, the natural graphite modified product of Shenzhen Bestray, after the spheroidization of natural flake graphite, is subjected to carbon coating treatment to obtain a first-time Coulombic efficiency of 93% and a discharge capacity of 365 mAh/g. ("Study on Modified Spherical Natural Graphite Lithium-ion Battery Anode Materials", Wang Guoping, Volume 13, Issue 3, 2005, 249～253 Synthetic Chemistry) CN 101117911 A Mentioned The negative electrode material prepared by the amorphous carbon coated natural graphite has an initial efficiency of more than 92%, and an initial discharge capacity of 355 mAh/g. The artificial graphite microspheres of Shanghai Shanshan Technology (see the company website of Shanghai Shanshan Technology) The specific capacity of the negative electrode sold is only 280-350mAh/g, which cannot break through the theoretical capacity. It can be seen that obtaining a higher capacity cannot be achieved by a single modification. the

However, other new anode materials with high theoretical processing capacity, such as silicon, tin, metal oxides, etc., have a large volume expansion in the process of deintercalating lithium, which makes their cycle performance poor, and the current technology is not mature. , limiting their commercial application. the

How to obtain a negative electrode material with high lithium storage capacity, high coulombic efficiency, good cycle performance, and good rate performance is one of the keys to improving the performance of lithium-ion batteries. Whether the cost is low and the process is simple and easy to become a material can be commercialized on a large scale Applied metrics. At present, there is no better material to meet the future demand for high-performance batteries. the

Contents of the invention

The purpose of the present invention is to provide a preparation method of a lithium-ion battery graphite negative electrode material containing a hollow carbon nanostructure with high lithium storage capacity, high coulombic efficiency, good cycle performance, good rate performance and low cost. the

The technical solution adopted in the present invention is: use pitch doped with metal nanoparticles as binder, graphite powder as aggregate, and adopt the method of hot pressing and sintering to complete pitch carbon coating graphite and carbonization and graphitization and a large amount of hollow carbon in one step The nanostructures are formed in situ. the

Concrete preparation method of the present invention is as follows:

(1) First, the explosion method is used to prepare nano-metal particle-doped asphalt: tar is used as the raw material for preparing asphalt, and inorganic salts or organic salts of transition metals and explosives (with low decomposition temperature) are added to the tar according to the mass ratio. Small molecular substances), during the temperature rise process in the prepared asphalt, the explosive agent reaches the decomposition temperature to produce a slight explosion, so that the metal salt is more uniformly dispersed, and then the temperature continues to rise, and finally the asphalt with nano-metal particles dispersed is prepared. For the specific preparation method, see "Preparation of Nano-nickel Particles Doped Pitch Fiber", Li Jin, Guo Quangui, etc., "Carbon" (Carbon) 2012, Volume 50, Issue 5, 2045-2047. (Li, Jin, Guo, Quangui, Shi, Jingli, Gao, Xiaoqing, Feng, Zhihai, Fan, Zhen,Liu, Lang, Preparation of Ni nanoparticle-doped carbon fibers Carbon ,2012,50,5, 2045-2047)

(2), Step (1) The asphalt obtained with nanometer metal particles is crushed and ground to obtain powdered asphalt with a particle size of 60 to 300 mesh, and set aside;

(3) Use powdered asphalt as the binder, and natural graphite with an average particle size of 5-30 μm as the aggregate. The amount of binder accounts for 20%-70% of the total mass. The two are ball milled or mechanically Stirring method to mix evenly;

(4) Using the method of hot pressing sintering, inert gas or carbon dioxide as protective gas, the treatment pressure is 1-50Mpa, the heat treatment method is: maintain the pressure, and raise the temperature to 2000-2000-2000- 3000°C, constant temperature heat treatment for 1-10h, and then naturally lowered to room temperature to obtain a block product, which is the active material of the electrode material; during this heat treatment process, the metal particles will gradually vaporize and volatilize until there is no or only a small amount of residue in the product;

(5) Process the bulk product into an active material powder with an average particle size of 5-30 μm to obtain a lithium-ion battery graphite negative electrode material containing a hollow carbon nanostructure.

The tar mentioned in the step (1) of the present invention can be selected from one or more of petroleum residues, coal tar, ethylene tar, heavy oil and other chemical products containing condensed ring aromatics. the

The transition metal described in step (1) of the present invention is iron, cobalt or nickel, and the inorganic salt of transition metal is transition metal nitrate. The organic salt of transition metal is oxalate, acetate or transition metal complex. the

In the asphalt of nano-metal particles prepared in the step (1) of the present invention, the shape of the nano-metal particles is a metal element or a metal oxide with a nano-scale particle size. The particle size distribution is 5-100 nm, and the average particle size is 10-50 nm. the

In the asphalt with nanometer metal particles prepared in the step (1) of the present invention, the nanometer metal particles account for 0.1-30% of the mass of the asphalt. the

The natural graphite described in the present invention is one or more graphite forms such as natural flake graphite, graphite microcrystal or spherical natural graphite, with an average particle size of 5-30 μm. the

The inert gas described in the present invention is nitrogen, argon or helium. the

The artificial graphite negative electrode material for lithium-ion batteries prepared by the present invention is composed of three components, including graphite components as aggregates, pitch carbon components as coatings and binders, and a large number of carbon nano-cavity parts . the

A large number of carbon nano cavity structures contained in the artificial graphite negative electrode material of the lithium ion battery prepared by the invention are hollow structures similar to onion fullerenes. It is an irregular polygonal structure, containing multi-layer graphene sheets. `` ``

Using the artificial graphite negative electrode material for lithium-ion batteries prepared by the present invention as raw material, according to the general preparation method of button batteries, the active material powder, conductive agent, and binder are mixed according to a certain mass ratio, added to nitrogen-methylpyrrolidone, and the magnetic force is dispersed ultrasonically. Negative electrode slurry was prepared by stirring and mixing, coated on copper foil, dried and cut into pieces as negative electrode sheets, assembled into batteries, and subjected to constant current charge and discharge tests. (For details, see "Lithium Ion Simulation Battery", Lithium Battery Information, 2010, Supplement No. 31.)

Compared with the prior art, the present invention has the following advantages,

Because the graphite is coated with pitch carbon and subjected to carbonization and graphitization treatment, the artificial graphite has the advantages of good solvent compatibility, high Coulombic efficiency and good cycle performance of ordinary artificial graphite. The surface of the artificial graphite anode material containing a large number of in-situ formed hollow carbon nanostructures is composed of graphitized pitch carbon, which has the properties of soft carbon, and is compatible with propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate Ester (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and other solvents have good compatibility, form a stable solid electrolyte (SEI) film, and avoid natural graphite caused by propylene carbonate intercalation between natural graphite layers The phenomenon of layer peeling makes the material have better cycle stability and longer service life. The initial efficiency of the negative electrode material is above 80%, and the subsequent Coulombic efficiency is mostly above 99%. At the same time, the nano-metal particles in the raw material for preparing the artificial graphite anode material are more uniformly dispersed in the raw material, and a series of changes will occur during the heat treatment process, and finally a carbon nano-cavity structure is formed in situ, which provides a large amount of lithium storage space and activity. At the same time, the lithium storage capacity of the material has been greatly improved, reaching 520 mAh/g (the capacity of most commercial graphite anode materials is in the range of 280-360 mAh/g at present.) At the same time, the rate performance of the material is also due to a large number of hollow The presence of carbon nanostructures has been greatly improved, and it can still reach 100-300 mAh/g at a high current density of 1000 mA/g. It can be used in ordinary lithium ion batteries and power lithium ion batteries, and has abundant sources of raw materials, low cost, simple manufacturing process and easy industrial production. the

Description of drawings

1 is a schematic cross-sectional structure diagram of an artificial graphite negative electrode material for a lithium ion battery according to Example 1 of the present invention. In the figure 1 is graphitized pitch carbon; 2 is carbon nano cavity structure; 3 is natural graphite. the

Fig. 2 is the schematic flow chart of the preparation of the artificial graphite negative electrode material for lithium ion battery of the embodiment of the present invention 1

Fig. 3 is the transmission electron microscopy spectrum of artificial graphite negative electrode material for lithium ion battery of the embodiment of the present invention 1

Fig. 4 is: the X-S ray diffraction spectrum of artificial graphite negative electrode material for lithium ion battery of the embodiment of the present invention 1

Fig. 5 is the first charge-discharge curve of the artificial graphite negative electrode material for lithium ion battery of the embodiment of the present invention 1, and current density is 50 mA/g.

Fig. 6 is the first charge and discharge curve that the product in the embodiment of the present invention 1 and comparative example 1 is used as negative electrode material, and current density is 50 mA/g.

Fig. 7 is the first charge-discharge curve that natural flake graphite is used as negative electrode material in comparative example 2 of the present invention, and current density is 50 mA/g.

Fig. 8 is the cycle performance of the artificial graphite negative electrode material for lithium ion batteries in Example 1 of the present invention.

Detailed ways

In order for those skilled in the art to better understand the technical solution of the present invention, the negative electrode material and preparation method of the lithium ion battery proposed by the present invention and the lithium ion battery are described in detail below with reference to the accompanying drawings.

Embodiment 1: Using ethylene tar as the raw material for preparing asphalt, adding nickel nitrate and picric acid (explosive agent) in the tar by mass ratio (adding 5g nickel nitrate and 5g picric acid in 100g ethylene tar), heating process in the asphalt preparation During the heating process, the nickel nitrate decomposes (begins to decompose at 110°C), and then continues to heat up, and the picric acid reaches the decomposition temperature (about 300°C) and produces a slight explosion, which makes the nickel oxide more evenly dispersed, and the temperature rises to 420°C. Continue to stir for about 0.5 hour, stop, and finally prepare pitch with uniform dispersion of nano-metal nickel particles. Among them, the mass fraction of metal in the asphalt is 10%, and after crushing, it is ground and passed through a 100-mesh standard sieve for future use. Select natural flake graphite as the graphite source, wet ball mill through a 100-mesh standard sieve, and set aside. Weigh the sieved pitch and graphite powder according to the mass ratio of 20:80, and mix them evenly by ball milling at a speed of 200r/min for 2 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high temperature hot pressing and sintering. Keep the pressure, the heating rate is about 2°C/min to 2750°C, and the constant temperature time at 2750°C is After 2 hours, the pressure was 25MPa. After natural cooling, the block product was taken out, processed into powder, and passed through a 100-mesh sieve to obtain the artificial graphite sample powder, which was set aside. the

The used half-cell testing method of the present invention is: make CR2016 type button cell, artificial graphite sample powder, N-methylpyrrolidone containing 10% polyvinylidene fluoride and 10% conductive acetylene black are mixed uniformly, are coated on copper foil, Put it in a vacuum drying oven and dry it in vacuum at 120°C for 10 hours for use. The simulated battery was assembled in a Shanghai Michelona glove box filled with argon, and the electrolyte was 1M LiPF ₆ +EC:DMC=1:1 (mass Ratio), using a lithium metal sheet as the counter electrode. The electrochemical performance is carried out on Wuhan Landian CT2001A battery test system, the charge and discharge system: the current density is 50 mA/g or 100mA/g, constant current charge and discharge, and the voltage range is 0.005-3.000v.

Comparative example 1, the asphalt in this example is not doped with metal nanoparticles. Other steps are the same as in Example 1, see Figure 6 for the first charge and discharge curve. the

In Comparative Example 2, natural flake graphite was used instead of artificial graphite as the negative electrode material of the lithium ion battery, and the test part was the same as in Example 1. the

Fig. 1 is a schematic diagram of the structure of the artificial graphite anode material for lithium-ion batteries proposed by the present invention. The anode material for lithium-ion batteries includes three closely bonded components, pitch carbon tightly wraps natural graphite, and has onion-like Fuller Alkene carbon nanocavity matrix. The three components play a synergistic role in improving the comprehensive performance of the material.

In this embodiment, the carbon nano-cavity structure is formed in situ. The carbon nano-cavity structure is numerous and uniformly dispersed throughout the material, which provides space and paths for the storage and transfer of lithium ions, and has a significant effect on improving the lithium storage capacity and rate performance of the material. the

Fig. 3 is the transmission electron microscope picture of artificial graphite negative electrode material for lithium-ion battery in the present embodiment 1, can see clearly that there is a large amount of carbon nano-cavity structures of onion fullerene class in the material, and the particle size distribution is relatively uniform . It is polygonal and has an onion-like fullerene structure with a cavity in the center. They are embedded in pitch carbon and closely associated with graphitic components, which facilitates the storage and transfer of lithium ions. It plays an important role in improving the electrochemical performance of materials. the

Fig. 4 is the XRD spectrum of artificial graphite negative electrode material for lithium-ion battery in the present embodiment 1. Line 1 represents the XRD pattern of the asphalt sample doped with metal particles treated at 1000 ° C, and line 2 represents the XRD pattern of the sample product treated at 2750 ° C, from which it can be seen that the degree of graphitization of the material increases with the increase of temperature, and the content of nickel then decrease. In the final product, very little. the

Figure 5 is the first charge and discharge curve of the product in Example 1, with the same current density of 50mA/g. the

Fig. 6 is the first charge and discharge curve of the product in embodiment 1 and the product of comparative example 1, and current density is identical, is 50 mA/g. It can be seen from Fig. 6 that the product prepared by the method provided by the present invention with pitch doped with metal particles has excellent performance and high specific capacity. the

Figure 7 is the first charge and discharge curve of the product in Comparative Example 2 (the negative electrode material is natural flake graphite), and the current density is the same, which is 50mA/g. the

According to Fig. 5, Fig. 7, compare two groups of charging and discharging curves and know, the capacity of the artificial graphite negative electrode material prepared by the preparation method of the present invention is greater than the capacity of natural flake graphite, also greater than the theoretical capacity of graphite: 372 mAh/g. At the same time, the first coulombic efficiency of the artificial graphite negative electrode material prepared by the preparation method of the present invention is also obviously higher than that of the natural flake graphite material. the

Fig. 8 is the cycle curve of the artificial graphite negative electrode material for lithium-ion battery in the present embodiment 1, and first 5 cycles are carried out under 50mA/g, and the following cycle is carried out under 100mA/g, thus shows that this product The capacity can still be around 440mAh/g when cycled at 100mA/g, which is significantly higher than the current commercial graphite products. the

Table 1 is embodiment 1-6, tap density and electrochemical test result of comparative example 1-2. the

Example 2, using coal tar as the raw material for preparing pitch, adding nickel nitrate and picric acid (explosive agent) (100g of coal tar with 1g of nickel nitrate and 5g of picric acid) in the coal tar by mass ratio, and raising the temperature in the prepared pitch Stir continuously during the heating process. During the heating process, nickel nitrate decomposes (begins to decompose at 75°C) to obtain nickel oxide. After continuing to heat up, picric acid reaches the decomposition temperature (about 300°C) and produces a slight explosion, which makes the nickel oxide more evenly dispersed. The temperature rises To 420°C, continue to stir for about 0.5 hours, stop, and finally prepare asphalt with uniform dispersion of nano-metal nickel particles. Among them, the mass fraction of metal in the asphalt is 1%, and after being crushed, it is ground through a 300-mesh standard sieve for future use. Choose natural flake graphite as the graphite source, wet ball mill through a 300-mesh standard sieve, and set aside. Weigh the sieved pitch and graphite powder according to the mass ratio of 50:50, and mix them evenly by ball milling at a speed of 200r/min for 2 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high-temperature hot-pressing and sintering. Keep the pressure, and the heating rate is about 2°C/min to 3000°C, and the time is 1 hour. The pressure is 10MPa. After natural cooling, the block product is taken out, processed into powder, and passed through a 300-mesh sieve to obtain the artificial graphite sample powder, which is set aside. Other steps are with embodiment 1. When used as lithium ion battery negative electrode, electrochemical performance is similar to embodiment 1. The test results are shown in Table 1. the

Example 3,

Use petroleum residue oil as the raw material for preparing asphalt, add iron nitrate and picric acid (explosive agent) in the petroleum residue oil according to the mass ratio (add 30g iron nitrate and 5g picric acid to 100g coal tar), during the heating process of the prepared asphalt Stir constantly, ferric nitrate decomposes to iron oxide during the heating process, then continue to heat up, picric acid reaches the decomposition temperature (about 300°C) and produces a slight explosion, which makes the iron oxide more uniformly dispersed, the temperature rises to 420°C, and continues to stir for about 0.5 Hours, stop, and finally modulated into asphalt with uniform dispersion of nano-metal iron particles. Among them, the mass fraction of metal in the asphalt is 20%, and after crushing, it is ground and passed through a 300-mesh standard sieve for future use. Select graphite microcrystals as the graphite source, wet ball mill through a 200-mesh standard sieve, and set aside. Weigh the sieved pitch and graphite powder according to the mass ratio of 30:70, and mix them evenly by ball milling at a speed of 200r/min for 5 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high-temperature hot-pressing and sintering. Keep the pressure, and the heating rate is about 2°C/min to 2500°C, and the time is 3 hours. The pressure is 50MPa. After natural cooling, the block product is taken out, processed into powder, and passed through a 300-mesh sieve to obtain the artificial graphite sample powder, which is set aside. Other steps are with embodiment 1. When used as lithium ion battery negative electrode, electrochemical performance is similar to embodiment 1. The test results are shown in Table 1.

Example 4

Heavy oil is used as the raw material for preparing asphalt, and cobalt oxalate and picric acid (explosive agent) are added to the heavy oil according to the mass ratio (15g cobalt oxalate and 5g picric acid are added to 100g heavy oil), and the asphalt is prepared. Stir continuously during the heating process. The cobalt oxalate decomposes, and then continues to heat up, picric acid reaches the decomposition temperature (about 300°C) and produces a slight explosion, so that the cobalt oxide is more uniformly dispersed, the temperature rises to 420°C, continues to stir for about 0.5 hours, stops, and finally adjusts to have Asphalt with uniform dispersion of nano-metal cobalt particles. Among them, the mass fraction of metal in the asphalt is 30%, and after crushing, it is ground and passed through a 100-mesh standard sieve for future use. Select natural flake graphite as the graphite source, wet ball mill through a 100-mesh standard sieve, and set aside. Weigh the sieved pitch and graphite powder according to the mass ratio of 30:70, and mix them uniformly by ball milling at a speed of 200r/min for 2 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high-temperature hot-pressing and sintering. Keep the pressure, and the heating rate is about 3°C/min to 2750°C, and the time is 7 hours. The pressure is 15MPa. After natural cooling, the block product is taken out, processed into powder, and passed through a 100-mesh sieve to obtain the artificial graphite sample powder, which is set aside. Other steps are with embodiment 1. When used as lithium ion battery negative electrode, electrochemical performance is similar to embodiment 1. The test results are shown in Table 1.

Example 5

Use ethylene tar as the raw material for preparing asphalt, add ferrocene and picric acid (explosive agent) in ethylene tar by mass ratio (add 15g ferrocene and 5g picric acid to 100g ethylene tar), during the heating process in the prepared asphalt Stir constantly, heat up to the decomposition temperature of picric acid (about 300°C) to produce a slight explosion, so that the ferrocene is more evenly dispersed, the temperature rises to 420°C, continue to stir for about 0.5 hours, stop, and finally prepare nano-metal iron particles Uniformly dispersed asphalt. Among them, the mass fraction of metal in the asphalt is 10%, and after crushing, it is ground and passed through a 100-mesh standard sieve for future use. Spherical graphite is selected as the graphite source, wet ball milled through a 100-mesh standard sieve, and set aside. Weigh the sieved asphalt and graphite powder according to the mass ratio of 30:70, and mix them evenly by mechanical stirring at a speed of 200r/min for 2 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high-temperature hot-pressing and sintering. Keep the pressure, and the heating rate is about 3°C/min to 2550°C for 10 hours. The pressure is 20MPa. After natural cooling, the block product is taken out, processed into powder, and passed through a 100-mesh sieve to obtain the artificial graphite sample powder, which is set aside. Other steps are with embodiment 1. When used as lithium ion battery negative electrode, electrochemical performance is similar to embodiment 1. The test results are shown in Table 1.

Example 6

Use ethylene tar as the raw material for preparing asphalt, add nickel nitrate and picric acid (explosive agent) in ethylene tar according to the mass ratio (add 15g nickel nitrate and 5g picric acid to 100g ethylene tar), and keep stirring during the heating process of the prepared asphalt , the temperature rises to the picric acid decomposition temperature (about 300°C) to produce a slight explosion, so that the nickel nitrate is more evenly dispersed, the temperature rises to 420°C, continues to stir for about 0.5 hours, stops, and finally prepares asphalt with uniform dispersion of nano-nickel particles . Among them, the mass fraction of metal in the asphalt is 15%, and after crushing, it is ground and passed through a 100-mesh standard sieve for future use. Spherical graphite is selected as the graphite source, wet ball milled through a 300-mesh standard sieve, and set aside. Weigh the sieved pitch and graphite powder according to the mass ratio of 40:60, and mix them uniformly by mechanical stirring at a speed of 200r/min for 2 hours. Take out the mixture and put it into a graphite mold, compact it, place it in a hot press, and prepare artificial graphite products by high-temperature hot-pressing and sintering. Keep the pressure, and the heating rate is about 3°C/min to 2750°C, and the time is 3 hours. The pressure is 30MPa. After natural cooling, the block product is taken out, processed into powder, and passed through a 100-mesh sieve to obtain the artificial graphite sample powder, which is set aside. Other steps are with embodiment 1. When used as lithium ion battery negative electrode, electrochemical performance is similar to embodiment 1. The test results are shown in Table 1.

Table 1

Claims (10)

1. contain a preparation method for the graphite negative material of lithium ion battery of hollow carbon nanostructure, it is characterized in that comprising following rapid:

(1) what, first adopt is that explosion method is prepared nano-metal particle doping pitch: adopt tar as the raw material of preparing pitch, in tar, add in mass ratio inorganic salts or organic salt and the burster (having the small-molecule substance of low decomposition temperature) of transition metal, in modulation pitch in temperature-rise period, burster reaches decomposition temperature and produces slight blast, make that slaine is more dispersed to be opened, continue afterwards to heat up, be finally modulated into the pitch that is dispersed with nano-metal particle;

(2), step (1) obtains the pitch of nano-metal particle through fragmentation, grinds, and obtains particle diameter and is the Powdered pitch of 60-300 order, for subsequent use;

(3), adopt Powdered pitch to make binding agent, average grain diameter is that the native graphite of 5-30 μ m does aggregate, the consumption of binding agent accounts for the 20%-70% of gross mass, adopts ball milling method or mechanical agitation method to mix the two;

(4), adopt the method for hot pressed sintering, be protective gas at inert gas or carbon dioxide, processing pressure is 1-50Mpa, heat treatment mode is: keep pressure, with the programming rate of 2-4 DEG C/min, be warming up to 2000-3000 DEG C, constant temp. heating is processed 1-10h, then be naturally down to room temperature, obtaining block product is electrode material activity material;

(5) block product is processed into average grain diameter at 5-30 μ m active matter powder, obtains the graphite negative material of lithium ion battery that contains hollow carbon nanostructure.

2. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that the described tar of step (1) is petroleum residual oil, coal tar, ethylene bottom oil, heavy oil containing one or more in the chemical products of condensed-nuclei aromatics.

3. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that the described transition metal of step (1) is iron, cobalt or nickel.

4. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that the inorganic salts of the described transition metal of step (1) are transition metal nitrate.

5. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that the organic salt of the described transition metal of step (1) is oxalates, acetate or transient metal complex.

6. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, it is characterized in that in the pitch of nano-metal particle prepared by step (1), the form of nano-metal particle is metal simple-substance or the metal oxide of nano-scale particle size, its particle diameter is distributed in 5-100 nm, and average grain diameter is at 10-50 nm.

7. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that in the pitch of nano-metal particle prepared by step (1), nano-metal particle accounts for the 0.1-30% of asphalt quality.

8. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, it is characterized in that described native graphite is one or more of natural flake graphite, graphite microcrystal or spherical natural graphite graphite form, average grain diameter is 5-30 μ m.

9. the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure as claimed in claim 1, is characterized in that described inert gas is nitrogen, argon gas or helium.

10. a graphite negative material of lithium ion battery that contains hollow carbon nanostructure, it is characterized in that the artificial graphite cathode material for lithium ion batteries that the preparation method of a kind of graphite negative material of lithium ion battery that contains hollow carbon nanostructure described in claim 1-9 any one makes, it is by the graphitic composition as aggregate, as bitumencarb component and three kinds of component compositions of carbon lar nanometric cavities part of coating layer and binding agent, carbon lar nanometric cavities structure is the hollow structure of class onion fullerene, be irregular polygonized structure, contain multi-layer graphene lamella.