CN104934608A - Preparation method of in-situ graphene coated lithium ion battery cathode material - Google Patents

Abstract

The invention discloses a preparation method of a graphene in-situ coating lithium ion battery positive electrode material, which mainly relates to the technical field of a lithium ion battery, and in particular relates to a preparation method of a graphene-modified lithium battery positive electrode material. The main purpose is to solve the problems of low electronic conductivity, poor cycle performance and poor coating effect of lithium-ion positive electrode materials in the prior art by physically doping graphene or carbon materials, and loose and easy coating. Disengaged technical issues. Using the chemical vapor deposition method, the carbon source directly generates graphene on the surface of the positive electrode material of the lithium battery, so that the graphene coats the positive electrode material of the lithium battery in situ. The graphene coating effect of the composite material is good and has high electrical conductivity.

Description

A kind of preparation method of graphene in situ coating lithium ion battery cathode material

technical field

The invention relates to the technical field of lithium ion batteries, relates to the application of graphene with high electronic conductivity in positive electrode materials of lithium ion batteries, and in particular to a preparation method for in situ coating of positive electrode materials of lithium ion batteries by graphene.

technical background

With the continuous development of science and technology, the development results of new green and high-efficiency energy are changing with each passing day. Lithium-ion batteries have become popular due to their high working voltage, high energy density, long cycle life, high charging efficiency, good safety performance, and strong adaptability to the environment. current research hotspot. A lithium-ion battery is a rechargeable battery that relies on the movement of lithium ions between the positive and negative electrodes. During charging and discharging, Li ⁺ intercalates and deintercalates back and forth between the two electrodes: when the battery is charged, Li + ^{+ Deintercalation} from the positive electrode, intercalation into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; similarly, when discharging (the process of using the battery), the lithium ions embedded in the carbon layer of the negative electrode come out and move back to the positive electrode. The more lithium ions returned to the positive electrode, the higher the discharge capacity (the process of lithium ions entering the positive electrode material is called intercalation, and the process of leaving is called deintercalation; the process of lithium ions entering the negative electrode material is called insertion, and the process of leaving is called deintercalation).

Lithium-ion batteries have been dominated by cathode materials such as lithium manganese oxide and lithium cobalt oxide since their inception: Lithium manganese oxide (LiMn ₂ O ₄ ) has the advantages of rich raw material resources, low price, non-toxic and pollution-free, but lithium manganese oxide ( LiMn ₂ O ₄ ) has defects such as fast capacity fading caused by Mn dissolution and Jahn-Teller effect, that is, poor cycle performance and poor high temperature performance, so the cycle performance and high temperature performance of lithium manganate still need to be further improved. At present, doping and surface modification are the main ways to improve the performance of lithium manganese oxide. Lithium iron phosphate (LiFePO ₄ ) has good lattice stability, and the intercalation and extraction of lithium ions have little effect on the lattice. It has good reversibility, and has light weight, large energy storage, high power, long life, and self- Lithium iron phosphate (LiFePO ₄ ) has become the most promising lithium-ion battery due to its small discharge coefficient, wide temperature range, abundant resources, good safety performance, non-toxic, environmentally friendly and applicable to some demanding conditions. However, pure lithium iron phosphate (LiFePO ₄ ) has problems such as poor low-temperature performance, poor electrical conductivity, low energy density, and poor processability, which limit its application in lithium-ion battery cathode materials. It is necessary to improve its conductivity by modifying or doping it. Traditional methods such as carbon material coating, high-valent metal ion doping, and metal nanoparticle mixing can all improve the conductivity of lithium iron phosphate (LiFePO ₄ ). However, the traditional modification method of carbon coating will reduce the volume energy density of the positive electrode material, and will also hinder the migration and diffusion of lithium ions. Therefore, in order to improve the rate performance of lithium iron phosphate (LiFePO ₄ ) and overcome the negative impact of carbon coating on the energy density of lithium iron phosphate (LiFePO ₄ ), it is hoped that the introduction of graphene on lithium iron phosphate (LiFePO ₄ ) Compound modification.

In recent years, graphene has been introduced into lithium-ion battery electrode materials to solve the problems of slow migration of lithium ions, poor electronic conductivity of electrodes, and increased resistivity between electrodes and electrolytes under high-rate charge and discharge. Graphene is a carbon material in which a single layer or several layers of carbon atoms are tightly packed into a two-dimensional hexagonal lattice structure. It is the thinnest and hardest nanomaterial known in the world. At room temperature, its electron mobility exceeds 15000cm ² /V·s, which is higher than carbon nanotubes and crystalline silicon; the resistivity is only about 10 ^-8 Ω·m, lower than copper and silver; the thermal conductivity is as high as 5300W/m·K, high in carbon nanotubes and diamond. Graphene is mainly used in solar cells, sensors, supercapacitors and various electronic devices. The combination of graphene and traditional lithium battery cathode materials shows some new electrochemical characteristics. Traditional lithium ion battery cathode materials generally have low electronic conductivity: such as LiCoO ₂ , LiMn ₂ O ₄ and LiFePO ₄ , whose electronic conductivity is ^10-4 , ^10-6 and ^10-9 S/cm. Graphene has good electrical conductivity and high mechanical strength, so the use of graphene's high electronic and ionic conductivity and high mechanical strength can significantly improve the high-current discharge and cycle performance of the material.

Due to graphene's large specific surface area, high mechanical strength, and extraordinary electrical conductivity, graphene has more advantages than modified materials for traditional lithium battery cathode materials. Graphene-coated lithium battery cathode materials are expected to break through traditional methods such as carbon coating and nano-metal ion doping, and achieve a breakthrough in high-capacity lithium-ion batteries. At present, the preparation methods of graphene mainly include mechanical glass method, silicon carbide epitaxy method, chemical vapor deposition method and graphene oxide reduction method, etc.

At present, some teams have successfully modified lithium-ion battery cathode materials such as lithium manganese oxide and lithium iron phosphate with graphene, but most of them only physically blend graphene with lithium-ion battery cathode materials:

Chinese patent document CN103872287A (publication number) discloses a kind of liFePO ₄ lithium-ion battery positive electrode material that graphene and carbon coat are mixed with ball mill, obtains the method of graphene/liFePO ₄ lithium-ion battery positive electrode composite material, but It is just a simple physical blending of graphene and lithium iron phosphate powder. The size of graphene is very small, and it is a nano-scale material. It is particularly difficult to disperse in lithium iron phosphate, and the coating effect is not good, and the coating is loose and easy to detach. Ding Y, Jiang Y, Xu F, et al.Preparation of nano-structured LiFePO ₄ /graphenecomposites by co-precipitation method[J].Electrochemistry Communications,2010,12(1):10-13. ) using (NH ₄ ) ₂ Fe(SO ₄ ) ₂₆ H _2O , NH ₄ H ₂ PO ₄ , LiOH and graphene to co-precipitate and then sinter the graphene/liFePO ₄ lithium ion battery cathode material, but liFePO The ₄ particles are only loosely loaded on the graphene sheet, which slightly increases the electronic conductivity of the liFePO ₄ lithium-ion battery cathode material. Zhou X, Wang F, Zhu Y, et al.Graphene modified LiFePO ₄ cathode materials for high powerlithium ion batteries[J].J.Mater.Chem.,2011,21(10):3353- 3358.) Invented a method for preparing graphene/liFePO ₄ cathode material for lithium-ion batteries: first prepare graphene oxide (GO) aqueous solution by hummer method, then mix graphene oxide (GO) aqueous solution with lithium iron phosphate and spray The graphene oxide/liFePO ₄ composite was prepared by drying, and finally the graphene/liFePO ₄ lithium-ion battery cathode material was prepared by reducing graphene oxide (GO) at high temperature. Although this method can effectively improve the electronic conductivity of liFePO ₄ lithium-ion battery cathode material, the preparation cycle of graphene oxide is too long, which is not conducive to production. Cui Yongli, China University of Mining and Technology (Cui Yongli, Xu Kun, Yuan Zheng, et al. Preparation and electrochemical properties of graphene/spinel LiMn ₂ O ₄ nanocomposites[J]. Journal of Inorganic Chemistry, 2013,29(1):50 -56.) Graphene/lithium manganese oxide nanocomposites were prepared by freeze-drying, but lithium manganate was only agglomerated on the surface of graphene sheets, rather than graphene coated on the surface of lithium manganate.

The present invention uses chemical vapor deposition (chemical vapor deposition, CVD) to directly grow graphene on the surface of the lithium battery positive electrode material, and obtains the graphene-coated lithium battery positive electrode material. Chemical vapor deposition (CVD) is a process technology in which the reacting substances react chemically under relatively high temperature and gaseous conditions, and the resulting solid substances are deposited on the surface of the heated solid substrate to obtain solid materials. The preparation process of chemical vapor deposition method is simple to operate, easy to control, low in cost, and can produce high-quality graphene with few layers. Using chemical vapor deposition to directly grow graphene on the surface of the lithium battery positive electrode material can not only overcome the disadvantage of graphene being easy to agglomerate and disperse during the coating process, but also improve the coating effect of graphene, making the coating The cover is not easy to loose and fall off.

Contents of the invention

In order to solve the low electronic conductivity of traditional lithium-ion battery cathode materials and the simple physical doping of graphene and lithium battery cathode materials in the prior art, the graphene powder dispersion that occurs after high-temperature sintering and coating, sintering package The coating effect is not good, and the coating is loose and easy to detach, resulting in a series of technical problems such as limited room for improving electronic conductivity. In the present invention, graphene is used to modify the positive electrode material of the lithium battery, and the graphene is directly grown on the surface of the positive electrode material of the lithium battery by chemical vapor deposition (CVD), so as to obtain the positive electrode material of the lithium battery coated with graphene.

The technical solution adopted by the present invention to solve its technical problems is:

A kind of preparation method of graphene in-situ coated lithium battery positive electrode material, its main feature is that through described preparation method: chemical vapor deposition (chemical vapor deposition, CVD) directly in-situ coated graphite on the surface of lithium battery positive electrode material alkene. The concrete steps of described method comprise:

A. Mix the catalyst, lithium battery positive electrode material powder and dispersant, add ball milling medium, put it into a ball mill for ball milling at a speed of 100-300r/min, the ball milling time is 1-5h, and mix the catalyst and lithium battery positive electrode material powder Uniform, uniform particle size, to obtain the precursor.

B. Place the obtained precursor in a drying furnace to dry the ball milling medium to obtain a dry mixed powder material of lithium battery positive electrode material, dispersant and catalyst.

C. Put the powder mixture obtained in step B into a reactor, put the reactor into a heating furnace, evacuate the reactor with a vacuum pump, and then pass in an inert carrier gas, and repeat it several times.

D. Raise the heating furnace to a certain temperature, feed the carbon source, and the carbon source will flow to the powder in the reactor with the inert carrier gas flow, and react with the powder for a certain period of time.

E. Turn off the temperature control device and the carrier gas device, cool down, and take out the sample.

The anode material of the lithium battery is one or a combination of lithium cobaltate, lithium titanate, lithium iron phosphate, lithium hexafluorophosphate, and lithium manganate.

The dispersant is one or a combination of acetylene black, polyacrylamide (PAM), polyacrylic acid (PAA), graphite, polyethylene glycol (PEG), glucose, and sucrose. 0-20% of the mass of the positive electrode material.

The catalyst is one or more of metal copper, metal nickel, metal iron, metal platinum, metal cobalt, metal rubidium, metal iridium, metal molybdenum, silicon dioxide, zinc oxide, aluminum oxide, magnesium oxide The combination of the catalyst accounts for 0.1% to 5% of the mass of the positive electrode material of the lithium battery. The ball milling medium is zirconia ball, agate ball, stainless steel ball.

The reaction vessel may be a glass vessel, a ceramic vessel, a crucible or a high temperature quartz vessel, and the inert carrier gas may be one or a combination of helium, nitrogen and argon.

The carbon source is one or more of methane, ethane, propane, ethanol, methanol, propanol, benzene, hexachlorobenzene, ethylene, acetylene, sucrose, glucose, polymethylmethacrylate (PMMA) The carbon source accounts for 1% to 10% of the mass of the positive electrode material of the lithium battery.

The reaction temperature of the heating furnace is 500-1000° C., and the reaction time is 10-200 minutes.

The beneficial effects of the present invention are:

A method for preparing graphene in-situ coated lithium battery positive electrode materials, using a new preparation method chemical vapor deposition (chemical vapor deposition, CVD) to directly in-situ coated graphene on lithium battery positive electrode materials, improving the researcher's The traditional simple physical blending of graphene to coat lithium battery cathode materials has problems such as easy agglomeration of graphene, poor dispersion effect in matrix materials, and poor coating effect, which can significantly improve the electronic conductivity of lithium battery cathode materials . The preparation of graphene-coated lithium battery cathode materials is simple, the experiment period is short, and graphene-coated lithium-ion battery cathode materials can be prepared efficiently and quickly. In addition to modifying lithium iron phosphate, lithium manganese oxide, lithium cobaltate, lithium titanate, lithium hexafluorophosphate and other lithium ion battery positive electrode materials, the invention can also modify other lithium ion battery positive electrode materials, and has a wide range of applications. Applying the lithium battery cathode material modified by the method of the present invention to the lithium ion battery will make the application field of the lithium ion battery more extensive, and has great value for the application of the lithium ion battery.

Description of drawings

Figure 1 is a laser Raman image of a graphene-coated lithium iron phosphate positive electrode material prepared by a method for preparing a graphene-in-situ coated lithium-ion battery positive electrode material according to the present invention.

Figure 2 is a scanning electron microscope image A of the prepared graphene-coated lithium iron phosphate cathode material.

Fig. 3 is a transmission electron microscope image of the prepared graphene-coated lithium iron phosphate cathode material.

Fig. 4 is an X-ray diffraction pattern of the prepared graphene-coated lithium manganate cathode material.

Fig. 5 is a transmission electron microscope image of the prepared graphene-coated lithium manganate cathode material.

Fig. 6 is a scanning electron microscope image B of the prepared graphene-coated lithium iron phosphate cathode material.

Detailed ways

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Example 1

1. Mix 1.5g of silicon dioxide powder and 30g of lithium iron phosphate powder into a ball mill with agate balls as the ball milling medium, and put them into the ball mill at a speed of 300r/min for 5 hours to obtain a precursor.

2. The obtained precursor is placed in a drying oven and dried to a constant weight to obtain a mixed powder material of lithium iron phosphate and a catalyst.

3. Put the powder mixture obtained in step 2 into a quartz tube, put the quartz tube into a heating furnace, evacuate the quartz tube with a vacuum pump, and then inject nitrogen gas, repeat 3 times.

4. Raise the temperature of the heating furnace to 650°C, inject 3mL of methane gas, react with the powder, and generate graphene to coat the surface of lithium iron phosphate.

5. After 50 minutes of reaction time, turn off the heating furnace, cut off the nitrogen gas and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain the graphene-coated lithium iron phosphate cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and measure its conductivity with the four-probe method to obtain the conductivity The rate is 4.2×10 ^-2 S/cm, and the electrical conductivity has been greatly improved. Accompanying drawing 1, and accompanying drawing 2 and accompanying drawing 3 are laser Raman picture, scanning electron microscope picture and transmission electron microscope picture of graphene-coated lithium iron phosphate cathode material respectively, from these figures it can be seen that graphene is very Well coated on the surface of lithium iron phosphate.

Example 2

1. Mix 1.5g of metallic nickel powder, 30g of lithium manganese oxide powder and 0.9g of graphite powder into a ball mill. Agate balls are used as the ball milling medium, and put into the ball mill for ball milling at a speed of 100r/min. The ball milling time is 3h to obtain a precursor .

2. Place the obtained precursor in a drying oven and dry it to a constant weight to obtain a mixed powder material of lithium manganate, dispersant and catalyst.

3. Put the powder mixture obtained in step 2 into a ceramic container, put the quartz tube into a heating furnace, vacuumize the quartz tube with a vacuum pump, and then inject nitrogen gas, repeat 3 times.

4. Raise the temperature of the heating furnace to 900°C, inject 2g of benzene, react with the powder, and generate graphene to coat the surface of lithium manganate.

5. After 50 minutes of reaction time, turn off the heating furnace, cut off the nitrogen gas and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain the graphene-coated lithium manganate cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and measure its conductivity with the four-probe method to obtain the conductivity The rate is 4.61×10 ^-4 S/cm, and the electrical conductivity has been greatly improved. Accompanying drawing 4 and accompanying drawing 5 are the X-ray diffraction figure and transmission electron microscope picture of the graphene-coated lithium manganate positive electrode material that the method of embodiment 2 obtains. It can be seen from the picture that graphene flakes are formed and are well coated on the surface of lithium manganese oxide.

Example 3

1. Mix 1g of metallic copper powder, 30g of lithium manganate powder and 6g of sucrose into a ball mill, use zirconia balls as the ball milling medium, and put them into the ball mill at a speed of 200r/min for 5 hours to obtain a precursor.

2. Put the obtained precursor in a drying oven and dry to constant weight to obtain a mixed powder material of lithium manganate, dispersant and catalyst.

3. Put the powder mixture obtained in step 2 into a quartz tube, put the quartz tube into a heating furnace, evacuate the quartz tube with a vacuum pump, and then pass in argon gas, repeating 3 times.

4. Raise the temperature of the heating furnace to 1000°C, inject 3g of methane, react with the powder, and generate graphene to coat the surface of lithium manganate.

5. After 100 minutes of reaction time, turn off the heating furnace, cut off the argon gas and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain the graphene-coated lithium manganate cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and measure its conductivity with the four-probe method to obtain the conductivity The rate is 4.03×10 ^-4 S/cm, and the electrical conductivity has been greatly improved.

Example 4

1. Mix 1g of metal nickel and metal molybdenum powder, 30g of lithium cobaltate powder and 4g of polyacrylic acid (PAA) into a ball mill, use agate balls as the ball milling medium, and put them into the ball mill at a speed of 250r/min for ball milling. For 4h, the precursor was obtained.

2. The obtained precursor is placed in a drying oven and dried to a constant weight to obtain a mixed powder material of lithium cobaltate, dispersant and catalyst.

3. Put the powder mixture obtained in step 2 into a ceramic container, put the quartz tube into the heating furnace, evacuate the quartz tube with a vacuum pump, then inject argon gas, and repeat 3 times.

4. Raise the temperature of the heating furnace to 800°C, feed 1g of ethylene, react with the powder, and generate graphene to coat the surface of lithium cobaltate.

5. After 70 minutes of reaction time, turn off the heating furnace, cut off the argon gas and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain the graphene-coated lithium cobalt oxide cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and use the four-probe method to measure its conductivity, conductivity It is 2.6×10 ^-2 S/cm, and the electrical conductivity has been greatly improved.

Example 5

1. Mix 1.8g of zinc oxide powder mixture, 30g of lithium cobaltate powder and 1g of acetylene black into a ball mill, use zirconia balls as the ball milling medium, put them into the ball mill at a speed of 280r/min for ball milling, and the ball milling time is 2h to obtain Precursor.

2. The obtained precursor is placed in a drying oven and dried to a constant weight to obtain a mixed powder material of lithium cobaltate, dispersant and catalyst.

3. Put the powder mixture obtained in step 2 into a ceramic container, put the quartz tube into a heating furnace, vacuumize the quartz tube with a vacuum pump, and then inject helium, repeating 3 times.

4. Raise the temperature of the heating furnace to 900°C, feed 1g of benzene, react with the powder, and generate graphene to coat the surface of lithium cobaltate.

5. After 60 minutes of reaction time, turn off the heating furnace, cut off the argon gas and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain the graphene-coated lithium cobalt oxide cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and use the four-probe method to measure its conductivity, conductivity It is 1.8×10 ^-2 S/cm, and the electrical conductivity has been greatly improved.

Example 6

1. Mix 2g of magnesium oxide powder mixture, 30g of lithium iron phosphate powder and 3g of glucose into a ball mill, use stainless steel balls as the ball milling medium, and put them into the ball mill for milling at a speed of 300r/min for 5 hours to obtain a precursor.

2. The obtained precursor is placed in a drying oven and dried to a constant weight to obtain a mixed powder material of lithium iron phosphate, a dispersant and a catalyst.

3. Put the powder mixture obtained in step 2 into a quartz tube, put the quartz tube into a heating furnace, evacuate the quartz tube with a vacuum pump, and then pass in argon gas, repeating 3 times.

4. Raise the temperature of the heating furnace to 600°C, feed 1.5g of hexachlorobenzene, react with the powder, and generate graphene to coat the surface of lithium iron phosphate.

5. After 55 minutes of reaction time, turn off the heating furnace, cut off the argon gas, and let it cool down slowly in a closed environment.

6. After cooling to room temperature, take out the sample to obtain a graphene-coated lithium iron phosphate cathode material, and grind the sample, vacuum dry it, press it, and sinter it, and use the four-probe method to measure its conductivity, conductivity It is 4.5×10 ^-2 S/cm, and the electrical conductivity has been greatly improved. Accompanying drawing 6 is the scanning electron microscope picture of graphene-coated lithium iron phosphate cathode material, can see from this picture, graphene is well coated on the surface of lithium iron phosphate.

The above is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto, and any changes or modifications made by those skilled in the art within the field of the present invention are covered by the patent of the present invention. within range.

Claims (8)

1. a preparation method for Graphene in-stiu coating anode material for lithium-ion batteries, is characterized in that described method, i.e. chemical vapour deposition technique (chemical vapor deposition, CVD), and the step of its preparation method comprises:

A. by catalyst, anode material of lithium battery powder and dispersant, after adding ball-milling medium, put into ball mill and carry out ball milling with rotating speed 100 ~ 300r/min, Ball-milling Time is 1 ~ 5h, make catalyst mix uniform particle diameter with anode material of lithium battery powder, obtain presoma;

B. the drying oven presoma obtained being placed in 50 ~ 100 DEG C is dried, and obtains dry anode material of lithium battery and the mixed-powder material of catalyst;

C. the mixture of powders of step B gained is put into reactor, reactor is put into heating furnace, with vacuum pump, reactor is vacuumized, then pass into inert carrier gas, repeated multiple timesly to carry out;

D. heating furnace is risen to uniform temperature, add carbon source, flow in reactor on powder with inert carrier gas, with powdered reaction a period of time;

E. close temperature regulating device, carrier gas device, cooling, take out sample.

2. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, is characterized in that: described anode material of lithium battery is the combination of one or more in cobalt acid lithium, lithium titanate, LiFePO4, lithium hexafluoro phosphate, LiMn2O4.

3. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, it is characterized in that: described dispersant is the combination of one or more in acetylene black, polyacrylamide (PAM), polyacrylic acid (PAA), graphite, polyethylene glycol (PEG), glucose, sucrose, and dispersant accounts for 0 ~ 20% of anode material of lithium battery powder quality.

4. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, it is characterized in that: described catalyst is the combination of one or more in metallic copper, metallic nickel, metallic iron, metal platinum, metallic cobalt, metal rubidium, metal iridium, metal molybdenum, silicon dioxide, zinc oxide, alundum (Al2O3), magnesium oxide, catalyst accounts for 0.1% ~ 5% of anode material of lithium battery quality, and ball-milling medium is zirconia ball, agate ball, stainless steel ball.

5. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, it is characterized in that: described reaction vessel can be glass container, ceramic vessel, crucible or high quartz container, described inert carrier gas can be one or more combination in helium, nitrogen, argon gas.

6. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, it is characterized in that: described carbon source is the combination of one or more in methane, ethane, propane, ethanol, methyl alcohol, propyl alcohol, benzene, hexachloro-benzene, ethene, acetylene, sucrose, glucose, polymethyl methacrylate (PMMA), and carbon source accounts for 1% ~ 10% of anode material of lithium battery quality.

7. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, is characterized in that: the heating reaction temperature of described heating furnace is 500-1000 DEG C.

8. the preparation method of a kind of Graphene in-stiu coating anode material for lithium-ion batteries according to claim 1, is characterized in that: the time that described carbon source and anode material of lithium battery react is 10 ~ 200min.