Amorphous carbon-based negative electrode material and preparation method and application thereof

Abstract

According to the amorphous carbon-based negative electrode material and the preparation method and application thereof, through early-stage low-temperature pre-carbonization heat preservation treatment, on the basis of maintaining the conventional long-time high-temperature carbonization effect, the high-temperature carbonization heat preservation time in the high-temperature carbonization stage is greatly shortened, huge energy consumption caused by long-time high-temperature carbonization is reduced, and the energy consumption is reduced. The material has the advantages of simple process, low cost and high initial coulombic efficiency, the charging specific capacity (350mAh. G <-1 >) of the material is far higher than that of a common carbon-based material, the defects on the surface of a carbon source are reduced, the energy density and cycle life of the battery can be effectively improved when the material is applied to the lithium / sodium ion battery, and the material has a wide application prospect and is simple in process, low in cost and suitable for industrial production. The method can be used for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of lithium / sodium ion batteries, and in particular to an amorphous carbon-based negative electrode material and a preparation method and application thereof. Background Art

[0002] In today's world, with the growing demand for energy storage and the frequent occurrence of problems such as the small global lithium reserves and uneven distribution, lithium-ion batteries are difficult to meet the application of large-scale energy storage technology. Sodium, which has similar physical and chemical properties to lithium, has advantages such as abundant global reserves, wide distribution and low cost, making sodium-ion batteries have very broad application prospects in large-scale grid energy storage and are considered to be an effective supplement to lithium-ion batteries.

[0003] Among the many negative electrode materials for sodium ion batteries, carbon-based materials are generally considered to be the most ideal negative electrode materials for sodium ion batteries due to their wide sources and low costs. In particular, hard carbon (HC) materials are expected to dominate the industrialization of SIB negative electrode materials due to their unique microstructure and relatively stable electrochemical properties. However, the commonly used hard carbon negative electrode materials have a low specific capacity (≤300mAh·g -1 ), the capacity of hard carbon is mainly provided by the low-voltage platform area with slow ion diffusion, and the short-range ordered structure of hard carbon leads to its insufficient conductivity, resulting in large voltage hysteresis at high rates. Therefore, the rate performance and long-cycle stability of hard carbon are poor, which greatly limits its large-scale application in sodium-ion batteries. Therefore, improving the conductivity during the carbonization process becomes a key factor in improving the Na storage capacity of hard carbon anodes in SIBs.

[0004] The preparation of existing amorphous carbon-based negative electrode materials often improves their electrochemical performance through long-term (3-5h) high-temperature carbonization. The high-temperature carbonization process consumes huge energy and is costly, which is not conducive to industrial production. How to develop an amorphous carbon-based negative electrode material with low energy consumption, low cost and excellent electrochemical performance has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide an amorphous carbon-based negative electrode material and a preparation method and application thereof.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides a method for preparing an amorphous carbon-based negative electrode material, comprising the following steps:

[0008] ① The carbon source precursor is subjected to low-temperature pre-carbonization treatment to obtain a carbon source intermediate phase, and the low-temperature pre-carbonization temperature is 80-1000°C;

[0009] ② After the carbon source mesophase is cooled, it is crushed, sieved, washed and dried;

[0010] ③ The dried carbon source intermediate phase is subjected to rapid high-temperature carbonization treatment, the rapid high-temperature carbonization temperature is 1000-1800°C, the carbonization time is 10-40 minutes, and an amorphous carbon-based negative electrode material is obtained after cooling.

[0011] Preferably, in step ①, the temperature of low-temperature pre-carbonization is 400-600°C.

[0012] Preferably, in step ①, the low-temperature pre-carbonization time is 1 to 3 hours. The heating rate of the low-temperature pre-carbonization is 1 to 10°C·min -1 .

[0013] Preferably, the carbon source precursor includes one or more of synthetic polymers, biomass, and fossil fuels.

[0014] Preferably, the carbon source precursor includes one or more of phenolic resin, epoxy resin, furan resin, polyacrylonitrile, cellulose, bamboo powder, wood powder, lignin, coconut shell charcoal, palm, corn straw, starch, sugarcane residue, petroleum coke, coal, and asphalt.

[0015] Preferably, in step ②, the carbon source intermediate phase is sieved to d 50 The value is between 2 and 50 μm.

[0016] Preferably, in step ②, the drying temperature is 80-120° C. and the drying time is 2-24 hours.

[0017] Preferably, in step ③, the carbon source mesophase is subjected to rapid high-temperature carbonization in an inert atmosphere. The inert gas flow rate is 10 to 40 mL min -1 , the inert atmosphere is selected from one or more of argon and nitrogen.

[0018] Preferably, in step ③, the heating rate of high temperature pre-carbonization is 1-10°C·min -1 .

[0019] A second aspect of the present invention provides a negative electrode plate, which includes an active substance, and the active substance includes an amorphous carbon-based negative electrode material, and the amorphous carbon-based negative electrode material is prepared by the preparation method of the amorphous carbon-based negative electrode material as described above.

[0020] The third aspect of the present invention provides a battery, characterized in that the battery is a sodium ion battery or a lithium ion battery, the battery comprises a negative electrode, a positive electrode, a separator, and an electrolyte, and the negative electrode comprises the negative electrode plate as described above.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The present invention uses the low-temperature pre-carbonization heat preservation treatment in the early stage to greatly shorten the high-temperature carbonization heat preservation time in the high-temperature carbonization stage while maintaining the conventional long-term high-temperature carbonization effect, thereby reducing the huge energy consumption caused by long-term high-temperature carbonization and saving the carbonization electricity cost. It shows a much higher charge capacity (350mAh·g -1 ), reducing the defects on the surface of the carbon source, and having a high coulombic efficiency for the first time. Applying it to lithium / sodium ion batteries can effectively improve the battery energy density and cycle life, and has broad application prospects. The process is simple and the cost is low, and it can be used for large-scale industrial production.

[0023] 2. The present invention performs low-temperature pre-carbonization and heat preservation treatment on the carbon source precursor to break the water, other volatile impurities and unstable chemical bonds in the precursor and slowly release them in the form of small molecules, which helps the precursor to initially form a relatively stable carbonaceous structural framework, so that a stable carbon-based microstructure can be constructed in the subsequent rapid high-temperature carbonization stage; the carbon source intermediate phase treated by low-temperature pre-carbonization is cooled to room temperature, crushed and sieved to ensure that the heating and reaction conditions of each particle in the subsequent high-temperature carbonization process are more consistent; deionized water is filtered, washed and dried to remove residual impurities; the carbon source intermediate phase is subjected to rapid high-temperature carbonization under the protection of an inert atmosphere, and an amorphous carbon-based negative electrode material is obtained after cooling to room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0025] Figure 1 The amorphous carbon-based negative electrode for the sodium ion battery prepared in Example 1 is 0.05A·g -1 The charge and discharge curves for the first three cycles under current density.

[0026] Figure 2 This is a graph of the sodium ion battery rate performance of the amorphous carbon-based negative electrode prepared in Example 1.

[0027] Figure 3 This is the SEM image of the amorphous carbon-based negative electrode prepared in Example 1.

[0028] Figure 4 The amorphous carbon-based negative electrode prepared in Example 4 is 0.05A·g -1 The charge and discharge curves of the sodium-ion battery in the first three cycles under current density.

[0029] Figure 5 This is a graph of the sodium ion battery rate performance of the amorphous carbon-based negative electrode prepared in Example 4.

[0030] Figure 6 This is the SEM image of the amorphous carbon-based negative electrode prepared in Example 4.

[0031] Figure 7 TGA graphs of the amorphous carbon-based negative electrodes prepared in Example 1 and Comparative Example 7. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example 1

[0034] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 10 min with a heating rate of 5 °C min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0035] Example 2

[0036] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.50 g / min and the high-temperature carbonization was carried out at 1400 °C for 20 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0037] Example 3

[0038] Weigh 5 g of phenolic resin and heat at 40 mL min -1The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 30 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0039] Example 4

[0040] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 40 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0041] Example 5

[0042] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 10 min with a heating rate of 5 °C min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0043] Example 6

[0044] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1, and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.50 g / min and the high-temperature carbonization was carried out at 1400 °C for 20 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0045] Example 7

[0046] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 30 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0047] Example 8

[0048] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 40 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0049] Example 9

[0050] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 30 min at a heating rate of 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 10 min with a heating rate of 5 °C min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0051] Example 10

[0052] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 30 min at a heating rate of 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 40 min with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0053] Embodiment 11

[0054] Weigh 1 g of wood powder and 4 g of phenolic resin, mix them evenly, introduce argon atmosphere at a flow rate of 40 mL / min, and pre-carbonize at 500 °C for 3 h with a heating rate of 2 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized mixture intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 h; the -1 The argon atmosphere was introduced at a flow rate of 1.500 ℃ and high-temperature carbonization was carried out at 1300 ℃ for 40 min with a heating rate of 2 ℃·min -1 After cooling to room temperature, the mixture was taken out to obtain an amorphous carbon-based negative electrode material.

[0055] Example 12

[0056] Weigh 5 g of bamboo powder, introduce argon gas at a flow rate of 40 mL / min, and pre-carbonize at 800 °C for 3 h at a heating rate of 2 °C min. -1 , and then take it out after cooling to room temperature; the pre-carbonized bamboo powder intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 h; the -1The argon atmosphere was introduced at a flow rate of 1.5 ℃ and high-temperature carbonization was carried out at 1400 °C for 40 min with a heating rate of 2 °C min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0057] Example 13

[0058] Weigh 5 g of coconut shell charcoal and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and pre-carbonized at 500 °C for 3 h with a heating rate of 2 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized coconut shell charcoal mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 h; the -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and high-temperature carbonization was carried out at 1400 °C for 30 min with a heating rate of 2 °C min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0059] Comparative Example 1

[0060] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and the mixture is dried at 80°C for 12 hours to obtain a carbon-based negative electrode material.

[0061] Comparative Example 2

[0062] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400℃ for 1 h with a heating rate of 5℃·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0063] Comparative Example 3

[0064] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized phenolic resin intermediate phase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 3 h with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0065] Comparative Example 4

[0066] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and the mixture is dried at 80°C for 12 hours to obtain a carbon-based negative electrode material.

[0067] Comparative Example 5

[0068] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400℃ for 1 h with a heating rate of 5℃·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0069] Comparative Example 6

[0070] Weigh 5 g of cellulose and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 500 °C for 3 h, and the heating rate was 5 °C min -1 , and then taken out after cooling to room temperature; the pre-carbonized cellulose mesophase is crushed and sieved to d 50The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80℃ for 12 hours; -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 3 h with a heating rate of 5 °C·min -1 , and then taken out after cooling to room temperature to obtain an amorphous carbon-based negative electrode material.

[0071] Comparative Example 7

[0072] Weigh 5 g of phenolic resin and heat at 40 mL min -1 The argon atmosphere was introduced at a flow rate of 1.5 ℃ and the high-temperature carbonization was carried out at 1400 °C for 10 min with a heating rate of 5 °C min -1 After cooling to room temperature, take out, crush the phenolic resin, and sieve to d 50 The value is between 2 and 50 μm; deionized water is filtered and washed, and dried at 80°C for 12 hours to obtain an amorphous carbon-based negative electrode material.

[0073] Due to the low-temperature pre-carbonization heat preservation treatment in the early stage, the high-temperature carbonization heat preservation time can be shortened in the high-temperature carbonization stage, and the effect of long-term high-temperature carbonization can be achieved at the same time, and the huge energy consumption caused by long-term high-temperature carbonization is reduced, saving the carbonization electricity cost. Those skilled in the art can select one or more mixtures of synthetic polymers (phenolic resins, epoxy resins, furan resins, polyacrylonitrile, etc.), biomass (cellulose, bamboo powder, wood powder, lignin, coconut shell charcoal, palm, corn stalks, starch, sugarcane residues, etc.), and fossil fuels (petroleum coke, coal, asphalt, etc.) according to actual needs for low-temperature pre-carbonization treatment, take out after cooling to room temperature, crush, screen, filter, wash, and dry, and then perform rapid high-temperature carbonization treatment under inert atmosphere protection to obtain an amorphous carbon-based negative electrode material.

[0074] like Figure 1 The amorphous carbon-based negative electrode prepared in Example 1 has a -1 The charge and discharge curves of the sodium-ion battery in the first three cycles under current density.

[0075] like Figure 2 , sodium ion battery rate performance diagram of the amorphous carbon-based negative electrode prepared in Example 1.

[0076] like Figure 3 , SEM image of the amorphous carbon-based negative electrode prepared in Example 1.

[0077] like Figure 4 The amorphous carbon-based negative electrode prepared in Example 4 has a -1 The charge and discharge curves of the sodium-ion battery in the first three cycles under current density.

[0078] like Figure 5 , sodium ion battery rate performance diagram of the amorphous carbon-based negative electrode prepared in Example 4.

[0079] like Figure 6 , SEM image of the amorphous carbon-based negative electrode prepared in Example 4.

[0080] like Figure 7 TGA graphs of the amorphous carbon-based negative electrodes prepared in Example 1 and Comparative Example 7.

[0081] As shown in Table 1, the performance of amorphous carbon-based negative electrode materials prepared in Examples 1-10 and Comparative Examples 3-6 shows that shortening the high-temperature carbonization time can achieve the effect of long-term high-temperature carbonization, and reduce the huge energy consumption caused by long-term high-temperature carbonization, saving the electricity cost of carbonization.

[0082] Table 1. Comparison of sodium ion battery performance of different pre-carbonized amorphous carbon-based negative electrode materials

[0083]

[0084]

[0085] Table 2. Comparison of Li-ion Battery Performance of Different Pre-carbonized Amorphous Carbon-based Anode Materials

[0086] Example Project <![CDATA[3A·g -1 Charge capacity (mAh g -1 )]]> Embodiment 11 170.36 Example 12 153.29 Example 13 162.74

[0087] The carbon-based negative electrode materials in Examples 1 to 10 and Comparative Examples 1 to 6 were tested for the initial charge and discharge capacity and rate performance of sodium ion batteries using a half-cell test method. The results are listed in Table 1. The half-cell test method is as follows: the prepared carbon-based material, conductive carbon black and sodium alginate are mixed evenly in a mass ratio of 8:1:1, and N-methylpyrrolidone is added to prepare a slurry. The slurry is evenly applied on a copper foil and dried in a vacuum drying oven at 80°C for 12 hours. The surface mass loading of hard carbon is about 1.5 to 3 mg cm -2 Glass fiber (GF / D) is used as the diaphragm, and the electrolyte is 1M NaPF 6 , dimethyl ether (DME) solution. The button cell was placed in an argon glove box (H 2 O,O 2 <0.1ppm). Using LAND CT3002A battery tester (LAND), the battery was tested at 0.001~2.5V (Vs.Na + As shown in Table 1, the charge capacity of the hard carbon negative electrode material of Example 4 is significantly greater than that of Example 1, with a capacity increase of 30 mAh·g -1 , at 3A·g -1At high current density, the capacity is increased by 180 mAh g compared with Example 1. -1 The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing an amorphous carbon-based negative electrode material, characterized in that: The steps include: ① The carbon source precursor is subjected to low-temperature pre-carbonization treatment to obtain a carbon source intermediate phase, and the low-temperature pre-carbonization temperature is 80-1000°C; ② After the carbon source mesophase is cooled, it is crushed, sieved, washed and dried; ③ The dried carbon source intermediate phase is subjected to rapid high-temperature carbonization treatment, the rapid high-temperature carbonization temperature is 1000-1800°C, the carbonization time is 10-40 minutes, and an amorphous carbon-based negative electrode material is obtained after cooling.

2. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: In step ①, the temperature of low-temperature pre-carbonization is 400-600°C.

3. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: In step ①, the low-temperature pre-carbonization time is 1 to 3 hours.

4. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: The carbon source precursor includes one or more of synthetic polymers, biomass, and fossil fuels.

5. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: The carbon source precursor includes one or more of phenolic resin, epoxy resin, furan resin, polyacrylonitrile, cellulose, bamboo powder, wood powder, lignin, coconut shell charcoal, palm, corn stalks, starch, sugarcane residue, petroleum coke, coal, and asphalt.

6. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: In step ②, the carbon source intermediate phase is sieved to d 50 The value is between 2 and 50 μm.

7. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: In step ②, the drying temperature is 80-120° C. and the drying time is 2-24 hours.

8. The method for preparing an amorphous carbon-based negative electrode material according to claim 1, characterized in that: In step ③, the carbon source intermediate phase is subjected to rapid high-temperature carbonization treatment in an inert atmosphere.

9. A negative electrode plate, characterized in that: The negative electrode plate includes an active substance, and the active substance includes an amorphous carbon-based negative electrode material. The amorphous carbon-based negative electrode material is prepared by the preparation method of the amorphous carbon-based negative electrode material according to any one of claims 1 to 8.

10. A battery, characterized in that: This battery is a sodium ion battery or a lithium ion battery, and the battery comprises a negative electrode, a positive electrode, a separator, and an electrolyte, and the negative electrode comprises the negative electrode sheet according to claim 9.

Images