Method for preparing hard carbon material from high-performance resin leftover material and application

Abstract

The invention discloses a method for preparing a hard carbon material from high-performance resin leftover materials and application, and belongs to the technical field of organic solid waste treatment and resource utilization. Comprising the following steps: cleaning the high-performance resin leftover material with a solvent, drying, pre-oxidizing and carbonizing or directly carbonizing, crushing and screening to obtain the hard carbon negative electrode material. The first coulombic efficiency of the prepared hard carbon material can reach 80%, the first circle charging specific capacity can reach 320mAh g <-1 >, and the hard carbon material can be applied to lithium ion batteries and sodium ion battery negative electrode materials.

Description

Technical Field

[0001] The invention belongs to the technical field of organic solid waste treatment and resource utilization, and specifically relates to a method for preparing a hard carbon negative electrode material by utilizing high-performance resin scraps and an application thereof. Background Art

[0002] High-performance resins are a type of material with high strength, high heat resistance, and excellent chemical stability. They are widely used in aerospace, automobile manufacturing, electronics, medical equipment and other fields. With the current diversified needs of various industries, high-performance resins are experiencing explosive growth, and will have great application potential in various industries in the future. Due to their high melting temperature and high melt viscosity, high-performance resins have inferior processing performance to general engineering plastics, and usually require mechanical processing to form. During the film breaking, edge cutting, and machining process, high-performance resins will generate a large amount of waste film, waste silk, waste products, thread, waste chips, material heads and other scraps and organic waste. With the increasing use of high-performance resins, the transformation and high-value-added utilization of high-performance resin waste has become a pressing issue.

[0003] Universal polymer materials can be reused by mechanical recycling, but for high-performance resins with high heat resistance, it is difficult to recycle them by mechanical methods. At present, the recycling technology of high-performance resin waste is mainly based on incineration, burial and chemical decomposition (for example, a method for recycling polyimide film waste, CN90102169.5; a method for recycling polyimide film, CN201110290741.4; a cracking and oil production device for waste resin powder, CN202323027373.1). The incineration method can recover heat, but there are problems of high energy consumption and high carbon emissions, and the incineration of high-performance resins containing nitrogen and sulfur atoms will produce harmful gases such as nitrogen oxides and sulfur dioxide. The burial method requires a large amount of land due to the difficulty of environmental degradation of high-performance resins. The chemical recovery method is to convert high-performance resins into small molecular monomers by catalytic cracking. However, chemical recovery often has a low recovery rate, and the added value of the small molecular monomers recovered is often low, and a large amount of catalysts and chemical reagents are required, resulting in three wastes pollution and energy waste. Therefore, there is an urgent need for a recycling method to achieve efficient, high-value, and low-carbon utilization of high-performance resin scraps.

[0004] High-performance resins have high heat resistance, contain aromatic and heterocyclic structures in their structures, have high residual carbon rates, and are excellent precursors for preparing hard carbon materials. However, their high prices limit their application in the precursors of high-performance hard carbon negative electrode materials. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for preparing hard carbon materials from high-performance resin scraps, which utilizes the high carbon residue rate of high-performance resins and realizes the efficient and high value-added utilization of low-value high-performance resin waste that is difficult to degrade through direct carbonization or pre-oxidation-carbonization process. To achieve the above-mentioned invention purpose, the technical solution adopted by the present invention is:

[0006] A method for preparing hard carbon material from high-performance resin scraps comprises the following steps:

[0007] (1) High-performance resin scraps are cleaned with solvent and dried;

[0008] (2) The cleaned high-performance resin scraps are subjected to pre-oxidation-carbonization treatment or direct carbonization treatment;

[0009] (3) The carbonized product is crushed and screened to obtain hard carbon material.

[0010] Furthermore, the high-performance resin scraps are waste films, waste wires, waste products, thread cuttings, waste chips or material ends generated during the film breaking, edge trimming and machining process of the high-performance resin.

[0011] Furthermore, the high-performance resin is one or a mixture of two or more of aramid, polyimide, polyaryletherketone, polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polyphenylene sulfide ketone, and polybenzimidazole.

[0012] Furthermore, the solvent used for cleaning is acetone, toluene or solvent oil.

[0013] Furthermore, the drying temperature is 50-150° C. and the drying time is 0.5-12 h.

[0014] Furthermore, the pre-oxidation temperature is 250-500° C.; the pre-oxidation time is 0.5-8 hours; and the pre-oxidation atmosphere is air, oxygen or a mixture of air and oxygen in any ratio.

[0015] Furthermore, the carbonization temperature is 700-1500° C.; the carbonization time is 0.5-8 hours; and the carbonization atmosphere is nitrogen or argon.

[0016] Furthermore, the particle size of the hard carbon material is less than 5 μm.

[0017] The hard carbon material is applied in lithium ion batteries and sodium ion batteries.

[0018] The beneficial effects of the present invention are:

[0019] 1) The present invention uses the scraps of high-performance resin as raw materials, and obtains high-value hard carbon materials through a simple pre-oxidation-carbonization process, thereby achieving high added value utilization of the scraps of high-performance resin.

[0020] 2.) The high-performance resin scraps used in the present invention have a dense structure and have not been used by users, but are directly recovered from the factory, and have a low impurity content. The obtained hard carbon material has the characteristics of high tap density and low ash content.

[0021] 3) The process proposed by the present invention has a stable source of raw materials, low price, simple process route, low equipment requirements, environmentally friendly and low-carbon process, high product added value, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 and 2 are XRD patterns of the hard carbon materials prepared in Example 1 and Example 9.

[0023] Figure 2 This is a graph of the reversible specific capacity of sodium ion batteries of the hard carbon materials prepared in Example 1 and Example 9 at a current density of 0.03 A / g. DETAILED DESCRIPTION

[0024] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but shall not limit the present invention in any way.

[0025] Example 1

[0026] The aramid waste was washed with acetone and dried at 80°C for 6 hours. Then it was placed in a rotary kiln, heated to 400°C in air, activated for 5 hours, and the obtained material was placed in a high-temperature furnace, heated to 1300°C, and carbonized for 2 hours in a nitrogen atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PMIA-O.

[0027] Example 2

[0028] The polyimide waste film was cleaned with 120# solvent oil and dried at 120°C for 8 hours. Then it was placed in a rotary kiln, heated to 460°C under air conditions, activated for 4 hours, and the obtained material was placed in a high-temperature furnace, heated to 1500°C, and carbonized for 0.5 hours under argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PI-O.

[0029] Example 3

[0030] The polyaryletherketone waste was washed with acetone and dried at 60°C for 12 hours. Then it was placed in a rotary kiln, heated to 350°C under oxygen conditions, activated for 8 hours, and the obtained material was placed in a tubular furnace, heated to 1100°C, and carbonized for 4 hours under argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PAEK-O.

[0031] Example 4

[0032] The polyphenylene ether head was washed with toluene and dried at 150°C for 7 hours. Then it was placed in a rotary kiln, heated to 360°C under the condition of air: oxygen = 1:1.5, activated for 6 hours, and the obtained material was placed in a tubular furnace, heated to 1400°C, and carbonized for 3 hours under argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PPO-O.

[0033] Example 5

[0034] The waste polyphenylene sulfide was washed with toluene and dried at 130°C for 5 hours. Then it was placed in a rotary kiln, heated to 250°C under oxygen conditions, activated for 2 hours, and the obtained material was placed in a tubular furnace, heated to 1000°C, and carbonized for 8 hours under argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PPS-O.

[0035] Example 6

[0036] The polyetheretherketone wire was cleaned with 6# solvent oil and dried at 110°C for 3.5 hours. Then it was placed in a rotary kiln, heated to 380°C under the condition of air: oxygen = 1:1, activated for 3 hours, and the obtained material was placed in a tubular furnace, heated to 900°C, and carbonized for 6 hours under nitrogen atmosphere. After screening, a hard carbon material with a particle size of less than 5μm was obtained, which was recorded as PEEK-O.

[0037] Example 7

[0038] The waste polyphenylene sulfide ketone was washed with acetone and dried at 80°C for 5.5 hours. Then it was placed in a rotary kiln, heated to 420°C under air conditions, activated for 5 hours, and the obtained material was placed in a tubular furnace, heated to 700°C, and carbonized for 1 hour under nitrogen atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PPSK-O.

[0039] Example 8

[0040] The polybenzimidazole material was washed with toluene and dried at 100°C for 0.5h. Then it was placed in a rotary kiln, heated to 500°C under oxygen conditions, activated for 1h, and the obtained material was placed in a tubular furnace, heated to 800°C, and carbonized for 5h under nitrogen atmosphere. After screening, a hard carbon material with a particle size of less than 5μm was obtained, which was recorded as PBI-O.

[0041] Example 9

[0042] The aramid fiber head was cleaned with 120# solvent oil and dried at 120°C for 3 hours. The obtained material was placed in a tube furnace, heated to 1200°C, and carbonized for 2 hours under argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PMIA-C.

[0043] Example 10

[0044] The polyimide waste film was washed with toluene and dried at 140°C for 4.5 hours. The obtained material was placed in a tube furnace, heated to 1100°C, and carbonized for 3 hours under an argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PI-C.

[0045] Embodiment 11

[0046] The waste polyetheretherketone was washed with acetone and dried at 100°C for 6 hours. The obtained material was placed in a tube furnace, heated to 1000°C, and carbonized for 1 hour under an argon atmosphere. After screening, a hard carbon material with a particle size of less than 5 μm was obtained, which was recorded as PEEK-C.

[0047] The structural data and battery results of each hard carbon material are listed in the table below.

[0048] Table 1

[0049]

[0050]

[0051] Application Example 1

[0052] The hard carbon materials described in Examples 1 to 11 are applied to negative electrode materials of lithium-ion batteries and sodium-ion batteries. The negative electrode material, acetylene black and polyvinylidene chloride are mixed evenly in a ratio of 8:1:1, dispersed in N-methylpyrrolidone, and then coated on copper foil and dried at 120°C for 12 hours to obtain an electrode. The lithium-ion battery uses lithium sheet as the other electrode, 1M lithium hexafluorophosphate ethylene carbonate, diethyl carbonate and ethyl methyl carbonate (volume ratio of 1:1:1) as the electrolyte, and glass fiber filter paper as the diaphragm to assemble the battery. The sodium-ion battery uses sodium sheet as the other electrode, 1M sodium perchlorate ethylene carbonate and diethyl carbonate (volume ratio of 1:1) as the electrolyte, and glass fiber filter paper as the diaphragm to assemble the battery.

[0053] The performance of lithium-ion batteries and sodium-ion batteries is shown in Table 1. By comparing PMIA-C and PMIA-O, it can be found that the interlayer spacing of the material after pre-oxidation is improved to a certain extent. As a negative electrode material, the initial coulombic efficiency and reversible capacity are improved to a certain extent. By comparing PI-O and PI-C and PEEK-O and PEEK-C, similar results can be obtained. The pre-oxidation-carbonization method can convert a variety of high-performance resins into hard carbon materials, which have considerable performance in lithium-ion batteries and sodium-ion batteries. The material obtained in the embodiment has a high tap density and a low ash content, which is ideal as a negative electrode material. The equipment used in the entire preparation process is relatively simple, which is conducive to industrial production.

Claims

1. A method for preparing hard carbon material from high-performance resin scraps, characterized in that: The following steps are involved: (1) High-performance resin scraps are cleaned with solvent and dried; (2) The cleaned high-performance resin scraps are subjected to pre-oxidation-carbonization treatment or direct carbonization treatment; (3) The carbonized product is crushed and screened to obtain hard carbon material.

2. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The high-performance resin scraps are waste films, waste wires, waste products, thread cuttings, waste chips or material ends generated during the film breaking, edge cutting and machining process of the high-performance resin.

3. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The high-performance resin is one or a mixture of two or more of aramid, polyimide, polyaryletherketone, polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polyphenylene sulfideketone and polybenzimidazole.

4. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The solvent used for cleaning is acetone, toluene or solvent oil.

5. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The drying temperature is 50-150° C. and the drying time is 0.5-12 hours.

6. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The pre-oxidation temperature is 250-500°C; the pre-oxidation time is 0.5-8h; and the pre-oxidation atmosphere is air, oxygen or a mixture of air and oxygen in any ratio.

7. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The carbonization temperature is 700-1500°C; the carbonization time is 0.5-8h; and the carbonization atmosphere is nitrogen or argon.

8. The method for preparing hard carbon material from high-performance resin scraps according to claim 1, characterized in that: The particle size of the hard carbon material is less than 5 μm.

9. The hard carbon material prepared by the method according to any one of claims 1 to 8 is used in lithium ion batteries and sodium ion batteries.

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