An asphalt and nano-nickel hybrid-coated anode material and its preparation method

Abstract

The present invention provides an asphalt and nano-nickel hybrid-coated anode material and a preparation method thereof. The preparation method includes the following steps: (1) Asphalt pretreatment; (2) Asphalt modification: Mix the pretreated asphalt and polymer, add them into a ball mill, ball mill, then heat to the molten state, shear and stir evenly, and pulverize after cooling to obtain modified asphalt; (3) Add 1 part by mass of spherical graphite into a coating machine, add 3-5 parts by mass of alcohol and 0.03-0.06 part by mass of surfactant, stir evenly, continue to add 0.4-0.6 part by mass of modified asphalt, stir evenly, then add 0.1-0.3 part by mass of metallic nickel, and continue to stir evenly to obtain a mixture; (4) Under a nitrogen atmosphere, calcine the mixture and cool it to room temperature to obtain the anode material. The anode material prepared by the present invention can endow the lithium-ion battery with high rate performance and low enthalpy change, and at the same time improve the temperature resistance of the lithium-ion battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery materials, and particularly relates to an asphalt and nano-nickel hybrid-coated anode material and a preparation method thereof. Background Art

[0002] With the continuous growth of the number of global fuel vehicles, the pressure brought by automobiles to the environment and energy is becoming increasingly severe. New energy vehicles can solve this problem, so they are attracting more and more attention globally. However, new energy vehicles still have many shortcomings, such as short cruising range, slow charging speed, etc. In particular, lithium metal plating is likely to occur on the surface of the anode material during high-rate charging, resulting in serious safety problems. The key to the development of new energy vehicles lies in the breakthrough of battery technology, and the update of battery technology lies in the innovation of materials.

[0003] Graphite is very suitable for the insertion and extraction of lithium ions during charge and discharge due to its good electrical conductivity, high degree of crystallization, good layered structure, etc., so it has become the most widely used anode material at present. However, the current anode material of lithium-ion batteries is graphite carbon material. When it is used under high or low temperature conditions, the high and low temperature discharge capacity of lithium-ion batteries is not good, the capacity is easy to rapidly decay, and the safety is greatly reduced. Therefore, it is crucial to expand the operating temperature range of lithium-ion batteries and develop anode materials with good heat resistance.

[0004] Graphite anode materials generally process graphite materials into spherical micropowders, and high-grade products have to go through the processes of coating, carbonization, and graphitization. Coating of spherical graphite micropowders means using polymer materials such as asphalt, resin, and sugar to wrap the surface of graphite microparticles, and then directly coating amorphous carbon by high-temperature carbonization or chemical vapor deposition to form a thin layer of amorphous carbon structure on the surface of spherical graphite micropowders, so as to improve the first efficiency and cycle performance of lithium-ion batteries.

[0005] The methods for coating spherical graphite micropowders with asphalt are roughly divided into three types, namely solid-phase mixing, liquid-phase mixing, and chemical vapor deposition. Liquid-phase mixing is more commonly used. During liquid-phase mixing coating, asphalt is dissolved in an organic solvent, then mixed, and after high-temperature treatment, the solvent is evaporated to form mesophase asphalt, and processes such as coating the graphite, removing light asphalt, and solvent are carried out, and then carbonization treatment is carried out to form coated carbon on the surface of carbon particles.

[0006] Therefore, there is an urgent need for an asphalt and nano-nickel hybrid-coated anode material and a preparation method thereof. Summary of the Invention

[0007] The purpose of the present invention is to provide an asphalt and nano-nickel hybrid-coated anode material and a preparation method thereof.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A preparation method of an asphalt and nano-nickel hybrid-coated anode material, the preparation method comprising the following steps:

[0010] (1) Asphalt pretreatment: After crushing the asphalt, pass it through a 200-300 mesh sieve, take the material under the sieve, add water with a mass 6-8 times that of the asphalt, mix evenly, add it to a sand mill for grinding, and end the grinding when D50 is 2-4 μm. Filter and dry to obtain pretreated asphalt;

[0011] (2) Asphalt modification: Mix the pretreated asphalt and the polymer in a mass ratio of (30-35):1, add them to a ball mill, ball mill at a speed of 400-600 rpm for 5-7 h, then heat to the molten state, shear and stir evenly, and crush after cooling to obtain modified asphalt;

[0012] (3) Add 1 part by mass of spherical graphite to a coating machine, add 3-5 parts by mass of alcohol and 0.03-0.06 parts by mass of surfactant, stir evenly under the condition of 500-700 rpm, continue to add 0.4-0.6 parts by mass of modified asphalt, stir evenly under the condition of 1000-1500 rpm, and then add 0.1-0.3 parts by mass of metallic nickel, and continue to stir evenly under the condition of 1000-1500 rpm to obtain a mixture;

[0013] (4) Under a nitrogen atmosphere, calcine the mixture. First, heat it at a rate of 2-5 °C / min to 90-95 °C and hold for 1-2 h; then continue to heat it at a rate of 6-10 °C / min to 900-950 °C and hold for 2-3 h. Finally, heat it at a rate of 12-15 °C / min to 1300-1350 °C and hold for 1-2 h; cool to room temperature to obtain the anode material.

[0014] Further, the D50 of the spherical graphite is between 10-15 μm, and the tapped density is 0.95-1.01 g / cm 3 。

[0015] Further, the polymer is selected from one or more of polyaniline, 3-octyl-substituted polythiophene, and polypyrrole.

[0016] Further, the polymer is a mixture of polyaniline, 3-octyl-substituted polythiophene, and polypyrrole with a mass ratio of 1:(1.3-1.5):(0.4-0.6).

[0017] The present invention uses three kinds of conductive polymers to modify asphalt. By utilizing their conductivity and electrochemical properties, the conductivity of the carbon layer can be improved. At the same time, since some conductive polymers volatilize during calcination, on the basis of the material structure formed by asphalt, metallic nickel and graphite, the volatilization of the polymer can further form a carbon layer with certain carbon micropores, improving the compactness of the negative electrode material, increasing the lithium intercalation rate and storage capacity, improving the rate performance and high-temperature resistance of the battery, and extending the service life.

[0018] Polyaniline was purchased from Macklin, product number P824522.

[0019] 3-Octyl-substituted polythiophene was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., product number Y19320

[0020] Polypyrrole was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., product number T25300.

[0021] Further, the metallic nickel is a mixture of metallic nickel with an average particle size of 20 nm and a specific surface area of 14 m 2 / g, metallic nickel with an average particle size of 50 nm and a specific surface area of 12 m 2 / g, and metallic nickel with an average particle size of 80 nm and a specific surface area of 11 m 2 / g in a mass ratio of 1:(1.4 - 1.6):(0.2 - 0.5). It was purchased from Jinlei Technology.

[0022] Further, the surfactant is sodium dodecyl sulfate, Tween 60 and a self-made surfactant in a mass ratio of 1:(0.2 - 0.5):(1.3 - 1.6).

[0023] Further, by mass fraction, the preparation method of the self-made surfactant includes the following steps:

[0024] S1: Add 150 parts of lauryl alcohol and 5 - 7 parts of potassium hydroxide to a stainless steel reactor. Keep the temperature at 30 - 35 °C, evacuate the reactor, heat up to 110 - 115 °C, add 1730 - 1740 parts of alkylene oxide, add it in 7 - 9 h, control the pressure at 0.1 - 0.3 MPa and the temperature at 115 - 120 °C, and react for 3 - 5 h to obtain polyether polyol;

[0025] S2: Add 900 parts of polyether polyol and 1220 - 1240 parts of glycerol to a stainless steel reactor. After replacing the nitrogen in the reactor, heat up to 142 - 146 °C, pressurize the reactor to 0.1 - 0.3 MPa. When the pressure in the reactor starts to drop, control the temperature at 115 - 120 °C and the pressure at 0.2 - 0.4 MPa, and react for 6 - 8 h to obtain the self-made surfactant.

[0026] Further, the alkylene oxide is a mixture of ethylene oxide, propylene oxide and 2,3-epoxybutane with a mass ratio of (0.5-0.8):1:(1.2-1.4).

[0027] In the self-made surfactant in the compound surfactant used in the present invention, part of the hydroxyl groups are retained and repeating alkane groups are also present. After being compounded with sodium dodecyl sulfate and Tween 60, the interfacial tension between graphite, asphalt and metallic nickel can be better reduced, and the modified asphalt and metallic nickel can be uniformly coated on the graphite, improving the rate performance and low-temperature resistance of the battery.

[0028] Further, the softening point of the asphalt is less than 95 °C.

[0029] Further, the softening point of the modified asphalt is 90-95 °C.

[0030] The present invention also provides an anode material coated with a mixture of asphalt and nano-nickel prepared by the preparation method.

[0031] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0032] 1. In the present invention, spherical graphite, modified asphalt and metallic nickel are mixed and coated in solvent alcohol, stirred evenly and extruded, so that the metallic nickel can be pressed into the gaps of the graphite. At the same time, the spherical graphite particles become flaky, and the metallic nickel is coated on the graphite through asphalt modification. The battery prepared with the anode material prepared by the present invention has excellent electrical performance, good low-temperature and high-temperature resistance, and broad market prospects.

[0033] 2. The present invention uses three conductive polymers to modify asphalt. By utilizing their conductivity and electrochemical properties, the conductivity of the carbon layer can be improved, the rate performance and high-temperature resistance of the battery can be improved, and the service life can be extended.

[0034] 3. The present invention uses a compound surfactant, which can better reduce the interfacial tension between graphite, asphalt and metallic nickel, enable the modified asphalt and metallic nickel to be uniformly coated on the graphite, and improve the rate performance and low-temperature resistance of the battery. Description of the Drawings

[0035] Figure 1 It is a resistivity test chart of the anode material of Example 1.

[0036] Figure 2 It is a backscattered light reference spectrum of the anode slurry prepared using the anode material of Example 1.

[0037] Figure 3 It is a transmitted light reference spectrum of the anode slurry prepared using the anode material of Example 1.

[0038] Figure 4SEM test diagram of the negative electrode sheet prepared using the negative electrode material prepared in Example 1. Detailed implementation manners

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0040] Example 1

[0041] This example provides a preparation method of an asphalt and nano-nickel mixed-coated negative electrode material, and the preparation method includes the following steps:

[0042] (1) Asphalt pretreatment: After crushing the asphalt, it is sieved through a 200-mesh sieve, the undersize is taken, water with a mass 7 times that of the asphalt is added, and they are mixed evenly. Then it is added to a sand mill for grinding. When D50 reaches 3 μm, the grinding ends. After filtration and drying, pretreated asphalt is obtained; the asphalt in this example is ordinary medium-temperature coal tar pitch with a softening point of 90.2 °C.

[0043] (2) Asphalt modification: The pretreated asphalt and the polymer with a mass ratio of 32:1 are mixed, added to a ball mill, and ball-milled at a speed of 500 rpm for 6 h. Then it is heated to the molten state, shear-stirred evenly, and crushed after cooling to obtain modified asphalt;

[0044] (3) Add 1 part by mass of spherical graphite to a coating machine, add 4 parts by mass of alcohol and 0.05 part by mass of surfactant, stir evenly under the condition of 600 revolutions per minute, continue to add 0.5 part by mass of modified asphalt, stir evenly under the condition of 1200 revolutions per minute, and then add 0.2 part by mass of metallic nickel, and continue to stir evenly under the condition of 1200 revolutions per minute to obtain a mixture;

[0045] (4) Under a nitrogen atmosphere, the mixture is calcined. First, it is heated to 92 °C at a rate of 4 °C / min and held for 1.5 h; then it is heated to 920 °C at a rate of 8 °C / min and held for 2.6 h. Finally, it is heated to 1320 °C at a rate of 14 °C / min and held for 1.4 h; cooled to room temperature to obtain the negative electrode material.

[0046] The D50 of the spherical graphite is 12 μm, and the tapped density is 0.97 g / cm 3 .

[0047] The polymer is a mixture of polyaniline, 3-octyl-substituted polythiophene, and polypyrrole with a mass ratio of 1:1.4:0.5.

[0048] Polyaniline was purchased from Macklin, with the product number P824522.

[0049] 3 - octyl substituted polythiophene was purchased from Shanghai Yuanye Bio - Technology Co., Ltd., with the product number Y19320

[0050] Polypyrrole was purchased from Shanghai Yuanye Bio - Technology Co., Ltd., with the product number T25300.

[0051] The metal nickel is a mixture of metal nickel with an average particle size of 20 nm, a specific surface area of 14 m 2 / g, metal nickel with an average particle size of 50 nm, a specific surface area of 12 m 2 / g, and metal nickel with an average particle size of 80 nm, a specific surface area of 11 m 2 / g, with a mass ratio of 1:1.5:0.3. It was purchased from Jinlei Technology.

[0052] The surfactant is sodium dodecyl sulfate, Tween 60 and a self - made surfactant with a mass ratio of 1:0.4:1.5.

[0053] By mass fraction, the preparation method of the self - made surfactant includes the following steps:

[0054] S1: Add 150 parts of lauryl alcohol and 6 parts of potassium hydroxide to a stainless - steel reactor. Keep the temperature at 32 °C, evacuate the reactor, heat up to 112 °C, add 1735 parts of alkylene oxide, and finish adding it in 8 h. Control the pressure at 0.2 MPa and the temperature at 117 °C, and react for 4 h to obtain polyether polyol;

[0055] S2: Add 900 parts of polyether polyol and 12230 parts of glycerol to a stainless - steel reactor. After replacing the nitrogen in the reactor, heat up to 144 °C, pressurize the reactor to 0.2 MPa. When the pressure in the reactor starts to drop, control the temperature at 117 °C and the pressure at 0.3 MPa, and react for 7 h to obtain the self - made surfactant.

[0056] The alkylene oxide is a mixture of ethylene oxide, propylene oxide and 2,3 - epoxybutane with a mass ratio of 0.7:1:1.3.

[0057] Example 2

[0058] This example provides a preparation method of an asphalt - nano - nickel hybrid - coated anode material. The preparation method includes the following steps:

[0059] (1) Asphalt pretreatment: After crushing the asphalt, sieve it through a 200 - mesh sieve, take the undersize, add water with a mass 6 times that of the asphalt, mix evenly, add it to a sand mill for grinding, and end the grinding when D50 is 2 μm. Filter and dry to obtain pretreated asphalt; The asphalt in this example is ordinary medium - temperature coal tar pitch with a softening point of 90.2 °C.

[0060] (2) Asphalt modification: Mix the pretreated asphalt and the polymer with a mass ratio of 30:1, add them into a ball mill, ball mill at a speed of 400 rpm for 5 h, then heat to the molten state, shear and stir evenly, and pulverize after cooling to obtain modified asphalt;

[0061] (3) Add 1 part by mass of spherical graphite into a coating machine, add 3 parts by mass of alcohol and 0.03 part by mass of surfactant, stir evenly under the condition of 500 revolutions per minute, continue to add 0.4 part by mass of modified asphalt, stir evenly under the condition of 1000 revolutions per minute, then add 0.1 part by mass of metallic nickel, and continue to stir evenly under the condition of 1000 revolutions per minute to obtain a mixture;

[0062] (4) Under a nitrogen atmosphere, calcine the mixture. First, heat it to 90 °C at a rate of 2 °C / min and keep it warm for 1 h; continue to heat it to 900 °C at a rate of 6 °C / min and keep it warm for 3 h, and finally heat it to 1300 °C at a rate of 12 °C / min and keep it warm for 2 h; cool it to room temperature to obtain the anode material.

[0063] The D50 of the spherical graphite is 12 μm, and the tapped density is 0.97 g / cm 3 。

[0064] The polymer is a mixture of polyaniline, 3-octyl-substituted polythiophene and polypyrrole with a mass ratio of 1:1.3:0.4.

[0065] Polyaniline is purchased from Macklin, product number P824522.

[0066] 3-octyl-substituted polythiophene is purchased from Shanghai Yuanye Bio-Technology Co., Ltd., product number Y19320

[0067] Polypyrrole is purchased from Shanghai Yuanye Bio-Technology Co., Ltd., product number T25300.

[0068] The metallic nickel is a mixture of metallic nickel with an average particle size of 20 nm and a specific surface area of 14 m 2 / g, metallic nickel with an average particle size of 50 nm and a specific surface area of 12 m 2 / g, and metallic nickel with an average particle size of 80 nm and a specific surface area of 11 m 2 / g, purchased from Jinlei Technology.

[0069] The surfactant is a mixture of sodium dodecyl sulfate, Tween 60 and a self-made surfactant with a mass ratio of 1:0.2:1.3.

[0070] Calculated by mass fraction, the preparation method of the self-made surfactant includes the following steps:

[0071] S1: Add 150 parts of lauryl alcohol and 5 parts of potassium hydroxide into a stainless - steel reactor. Keep the temperature at 30°C, evacuate the reactor, heat up to 110°C, add 1730 parts of alkylene oxide, and finish adding it in 7 hours. Control the pressure at 0.1 MPa and the temperature at 115°C, and react for 3 hours to obtain polyether polyol.

[0072] S2: Add 900 parts of polyether polyol and 1220 parts of glycerol into a stainless - steel reactor. After replacing the nitrogen in the reactor, heat up to 142°C, pressurize the reactor to 0.1 MPa. When the pressure in the reactor starts to drop, control the temperature at 115°C and the pressure at 0.2 MPa, and react for 6 hours to obtain a self - made surfactant.

[0073] The alkylene oxide is a mixture of ethylene oxide, propylene oxide, and 2,3 - epoxybutane with a mass ratio of 0.5:1:1.2.

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 1 is that when D50 is 10 μm, the grinding is ended, filtered, and dried to obtain pretreated asphalt.

[0076] Comparative Example 2

[0077] The difference between this comparative example and Example 1 is that the D50 of the spherical graphite is between 25 μm, and the tapped density is 0.91 g / cm 3 .

[0078] Comparative Example 3

[0079] The difference between this comparative example and Example 1 is that the polymer is a mixture of polyaniline, 3 - octyl - substituted polythiophene, and polypyrrole with a mass ratio of 1:1:1.

[0080] Comparative Example 4

[0081] The difference between this comparative example and Example 1 is that the metallic nickel is a mixture of metallic nickel with an average particle size of 20 nm and a specific surface area of 14 m 2 / g, metallic nickel with an average particle size of 50 nm and a specific surface area of 12 m 2 / g, and metallic nickel with an average particle size of 80 nm and a specific surface area of 11 m 2 / g with a mass ratio of 1:1:1. Purchased from Jinlei Technology.

[0082] Comparative Example 5

[0083] The difference between this comparative example and Example 1 is that the metallic nickel is a mixture of metallic nickel with an average particle size of 100 nm and a specific surface area of 9.8 m 2 / g, metallic nickel with an average particle size of 200 nm and a specific surface area of 8.5 m 2Metal nickel with a content of / g and metal nickel with an average particle size of 300 nm and a specific surface area of 8.2 m 2 were mixed. Purchased from Jinlei Technology Co., Ltd.

[0084] Comparative Example 6

[0085] The difference between this comparative example and Example 1 is that the surfactant is sodium dodecyl sulfate, Tween 60 and a self-made surfactant with a mass ratio of 1:1:1.

[0086] Calculated by mass fraction, the preparation method of the self-made surfactant includes the following steps:

[0087] S1: Add 150 parts of lauryl alcohol and 6 parts of potassium hydroxide to a stainless steel reactor, keep the temperature at 32 °C, evacuate the reactor, raise the temperature to 112 °C, add 1735 parts of alkylene oxide, and finish adding in 8 h. Control the pressure at 0.2 MPa and the temperature at 117 °C, and react for 4 h to obtain polyether polyol;

[0088] S2: Add 900 parts of polyether polyol and 12230 parts of glycerol to a stainless steel reactor. After purging the reactor with nitrogen, raise the temperature to 144 °C, pressurize the reactor to 0.2 MPa. When the pressure in the reactor starts to drop, control the temperature at 117 °C and the pressure at 0.3 MPa, and react for 7 h to obtain the self-made surfactant.

[0089] Comparative Example 7

[0090] The difference between this comparative example and Example 1 is that the alkylene oxide is a mixture of ethylene oxide, propylene oxide and 2,3-epoxybutane with a mass ratio of 1:1:1.

[0091] Performance Test

[0092] Take the negative electrode materials of Examples 1-2 and Comparative Examples 1-7 as samples, and form a battery according to the ratio (mass ratio) in Table 1.

[0093] Table 1 Battery Ratio

[0094]

[0095] 1. Negative Electrode Material Evaluation

[0096] The negative electrode material prepared in Example 1 has a compaction density of 2.005 g / cm at 1 t 3 , and the variation of resistivity with pressure is as Figure 1 shown. It can be seen from Figure 1 that the resistivity decreases with the increase of pressure and tends to be stable after 50 Mpa. The resistivity at 60 Mpa is 0.0023 Ω·cm.

[0097] 2. Negative Electrode Slurry Performance

[0098] It can be seen from Figure 2-3 that the stability change of the negative electrode slurry prepared from the negative electrode material in Example 1 within 24 hours is 0.5%, and the slurry stability is good.

[0099] 3. Performance test of negative electrode sheet

[0100] The SEM image of the negative electrode sheet prepared in Example 1 is shown in Figure 4 . From the SEM results, it can be seen that the microscopic morphology of the negative electrode sheet has distinct particles, and there is adhesion between particles after charge and discharge.

[0101] 4. Refer to GB / T24533-2019 to conduct electrical performance tests on the batteries prepared with the negative electrode materials of Examples 1-2 and Comparative Examples 1-7. The results are shown in Table 2.

[0102] Table 2 Electrical performance test results

[0103]

[0104] It can be seen from Table 1 that the batteries prepared with the negative electrode materials of Examples 1-2 have excellent electrical performance, especially the comprehensive performance of Example 1 is the most prominent, which is mainly due to the synergistic effect between raw materials.

[0105] In Comparative Examples 1-2, the particle size of the pretreated asphalt and the particle size of the spherical graphite were changed, and it can be seen that the performance effect of the battery decreased, which proves that the particle sizes of these two raw materials have an impact on the performance of the battery. In Comparative Example 3, the polymer ratio was changed, and it can be seen from the results that the high-temperature resistance performance of the battery was affected. Different parameter ratios of nickel in Comparative Examples 4-5 also affect the performance of the battery. And it can be known from Comparative Examples 6-7 that changing the surfactant will reduce the low-temperature resistance performance of the battery. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0106] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of an asphalt and nano-nickel hybrid-coated anode material, characterized in that, The preparation method includes: (1) Asphalt pretreatment: After crushing the asphalt, it is sieved through a 200-300 mesh sieve, and the undersize is taken. Water with a mass 6-8 times that of the asphalt is added, and they are mixed evenly. Then it is added to a sand mill for grinding. When the D50 reaches 2-4 μm, the grinding ends. After filtration and drying, the pretreated asphalt is obtained; (2) Asphalt modification: The pretreated asphalt and the polymer with a mass ratio of (30-35):1 are mixed and added to a ball mill. It is ball-milled at a speed of 400-600 rpm for 5-7 h, then heated to the molten state, sheared and stirred evenly, and crushed after cooling to obtain the modified asphalt; (3) Add 1 part by mass of spherical graphite to a coating machine, add 3-5 parts by mass of alcohol and 0.03-0.06 part by mass of surfactant, stir evenly, continue to add 0.4-0.6 part by mass of modified asphalt, stir evenly, and then add 0.1-0.3 part by mass of metallic nickel, and continue to stir evenly to obtain a mixture; (4) Under a nitrogen atmosphere, the mixture is calcined. First, it is heated from room temperature to 90-95 °C at a rate of 2-5 °C / min and held for 1-2 h; then it is heated to 900-950 °C at a rate of 6-10 °C / min and held for 2-3 h. Finally, it is heated to 1300-1350 °C at a rate of 12-15 °C / min and held for 1-2 h; after cooling to room temperature, the negative electrode material is obtained; The polymer is a mixture of polyaniline, 3-octyl-substituted polythiophene and polypyrrole with a mass ratio of 1:(1.3-1.5):(0.4-0.6); The surfactant is a mixture of sodium dodecyl sulfate, Tween 60 and a self-made surfactant with a mass ratio of 1:(0.2-0.5):(1.3-1.6); The preparation method of the self-made surfactant includes: S1: Add 150 parts of lauryl alcohol and 5-7 parts of potassium hydroxide to a stainless steel reactor. Keep the temperature at 30-35 °C, evacuate the reactor, heat it to 110-115 °C, add 1730-1740 parts of alkylene oxide, and finish adding it in 7-9 h. Control the pressure at 0.1-0.3 MPa and the temperature at 115-120 °C, and react for 3-5 h to obtain polyether polyol; S2: Add 900 parts of polyether polyol and 1220-1240 parts of glycerol to a stainless steel reactor. After replacing the nitrogen in the reactor, heat it to 142-146 °C, and pressurize the reactor to 0.1-0.3 MPa. When the pressure in the reactor starts to drop, control the temperature at 115-120 °C and the pressure at 0.2-0.4 MPa, and react for 6-8 h to obtain the self-made surfactant.

2. The preparation method of the asphalt and nano-nickel hybrid-coated anode material according to claim 1, wherein The D50 of the spherical graphite is between 10 and 15 μm, and the tapped density is 0.95 - 1.01 g / cm 3 .

3. The preparation method of the asphalt and nano-nickel mixed-coated anode material according to claim 1, characterized in that, The nickel metal is a mixture of nickel metals with an average particle size of 20 nm, a specific surface area of 14 m 2 / g, an average particle size of 50 nm, a specific surface area of 12 m 2 / g, and an average particle size of 80 nm, a specific surface area of 11 m 2 / g, with a mass ratio of 1:(1.4 - 1.6):(0.2 - 0.5).

4. The preparation method of the asphalt and nano-nickel hybrid-coated anode material according to claim 1, wherein, The alkylene oxide is a mixture of ethylene oxide, propylene oxide and 2,3-epoxybutane with a mass ratio of (0.5-0.8):1:(1.2-1.4).

5. The preparation method of the asphalt and nano-nickel hybrid-coated anode material according to claim 1, characterized in that, The softening point of the modified asphalt is 90-95 °C.

6. An asphalt, nano-nickel mixed-coated negative electrode material prepared by the preparation method according to any one of claims 1-5.

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