A method for preparing hard carbon negative electrode material by using recycled waste resin and its application

Abstract

The present invention discloses a method for preparing hard carbon negative electrode material by using recycled waste resin, which relates to the technical field of battery materials, including washing the recycled waste resin, crushing it into particles, immersing it in an activator for activation, cracking, acid immersion treatment, water washing, carbonization treatment and the like. The hard carbon negative electrode material obtained by the method of the present invention has a suitable specific surface area, a moderate interlayer distance, a gram capacity of more than 300 mAh / g, and a first efficiency of more than 85%. The product performance is good and can meet the application in the fields of lithium batteries, sodium batteries, potassium batteries, supercapacitors, etc. The present invention uses waste resin as the initial raw material to prepare the hard carbon negative electrode material, and treats the difficult biodegradable polymer resin material in an ingenious way, turning waste into treasure, which not only solves the problem of environmental pollution, but also solves the problem of high cost of raw materials for hard carbon negative electrode materials, and has broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of battery materials, in particular to a method for preparing hard carbon negative electrode materials by utilizing recycled waste resins and application thereof. Background Art

[0002] Common carbon-based negative electrode materials for batteries include graphite, soft carbon and hard carbon (hard carbon negative electrode materials), among which hard carbon is generally pyrolytic carbon obtained by pyrolysis of high molecular polymers and biomass. Due to the unique microstructure of the precursor, it undergoes a solid-phase carbonization process during the carbonization process and is difficult to graphitize. Since the microstructure of hard carbon materials presents a disordered amorphous structure, it can provide more active sites for charge storage and provide wide channels for diffusion and transport within the material, which is beneficial to the charge and discharge performance of the battery under large currents. Therefore, hard carbon has broad application prospects in battery materials.

[0003] On the other hand, with the development of polymer technology, polymer resins play an important role in people's lives, so a large amount of waste resins will be generated, such as polyvinyl chloride resins, phenolic resins, polystyrene resins, etc. These resins are difficult to degrade in nature, and direct abandonment, landfill or incineration will seriously pollute the environment, and recycling also requires high recycling costs. Therefore, how to turn waste into treasure and use waste resins to prepare hard carbon negative electrode materials with excellent performance such as gram capacity and first efficiency has always been a hot topic of research. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a method and application of preparing hard carbon negative electrode material by recycling waste resin.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0007] ① Wash the recycled waste resin, remove inorganic impurities such as dust and clay, and then crush it into 50-100 mesh particles, soak it in an activator, heat it to above 50°C under stirring, keep it warm for 1-10 hours, filter, wash with water, and dry it to obtain activated resin particles;

[0008] The activator is one of concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, a dichloroethane solution of ferric chloride, a dichloroethane solution of aluminum chloride, oleum or chlorosulfonic acid;

[0009] ② Place the activated resin particles obtained in step ① into a muffle furnace, heat to 200-500° C., and keep warm for 0.5-5 hours to perform cracking treatment to obtain cracked resin;

[0010] ③ Soak the cracked resin obtained in step ② in an inorganic acid solution for 1 to 10 hours, then rinse with deionized water until neutral, dry to obtain a dry resin, and grind the dry resin to a particle size D50 of 2 to 20 μm to obtain a dry resin powder;

[0011] ④ Place the dry resin powder obtained in the step into an atmosphere furnace or a rotary kiln, heat it to 600-1500°C for carbonization treatment for 1-5 hours under nitrogen protection, cool it down, and discharge it to obtain a hard carbon negative electrode material.

[0012] Preferably, the type of the recycled waste resin is one or more of polyvinyl chloride resin, phenolic resin or polystyrene resin.

[0013] Preferably, the mass ratio of the recycled waste resin to the activator is 1:5-10.

[0014] Preferably, the concentration of concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, oleum or chlorosulfonic acid is the highest concentration conventionally available on the market.

[0015] Preferably, the inorganic acid solution is a hydrochloric acid solution, a sulfuric acid solution or a nitric acid solution with a mass concentration of 2-8%.

[0016] Preferably, the temperature of the carbonization treatment is 900-1000° C., and the treatment time is 3-4 hours.

[0017] The present invention also includes the use of the hard carbon negative electrode material obtained by the method for preparing the hard carbon negative electrode material by utilizing the recycled waste resin in the preparation of lithium batteries, sodium batteries, potassium batteries and supercapacitors.

[0018] Compared with the prior art, the present invention has the following advantages and effects:

[0019] The hard carbon negative electrode material obtained by the method of the present invention has a specific surface area of ​​2-20m 2 / g, the distance between layers is d 002 At 0.37-0.40nm, the sodium removal capacity exceeds 300 mAh / g, and the first efficiency exceeds 85%. The product performance is good and can meet the application needs in lithium batteries, sodium batteries, potassium batteries, supercapacitors and other fields.

[0020] The present invention uses waste resin as the initial raw material to prepare hard carbon negative electrode material, and ingeniously processes the biodegradable polymer resin material to turn waste into treasure, which not only solves the problem of environmental pollution, but also solves the problem of high raw material cost of hard carbon negative electrode material, and has broad application prospects.

[0021] Compared with hard carbon negative electrode materials made from coal or biomass, polymer resin-based hard carbon negative electrode materials have lower ash content and less heavy metal residue, which can improve the specific capacity and cycle performance of the negative electrode materials; due to their high specific surface area, they can improve rate performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD test result diagram of the hard carbon negative electrode material obtained in Example 6;

[0023] Figure 2 This is the SEM test result of the hard carbon negative electrode material obtained in Example 6. DETAILED DESCRIPTION

[0024] The object of the present invention is to provide a method for preparing a hard carbon negative electrode material by utilizing recycled waste resin. The present invention is further described below in conjunction with specific embodiments.

[0025] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0026] ① Wash the recycled waste resin, remove inorganic impurities such as dust and clay, and then crush it into 10-100 mesh particles, soak it in an activator, heat it to above 50°C under stirring, keep it warm for 1-10 hours to activate the reaction, filter, wash with water, and dry it to obtain activated resin particles;

[0027] The activation temperature can be 50~boiling temperature, such as inorganic concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, oleum, chlorosulfonic acid can be heated to 50~200℃, Lewis acid can be heated to 50~80℃;

[0028] The activator is one of concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, a dichloroethane solution of ferric chloride, a dichloroethane solution of aluminum chloride, fuming sulfuric acid or chlorosulfonic acid.

[0029] The activated resin particles obtained above contain functional groups, such as one or a combination of sulfonic acid groups, phosphoric acid groups, nitro groups, carboxyl groups (partial branched chain oxidation products), carbon oxygen bonds (partial branched chain oxidation products), etc.;

[0030] ② Place the activated resin particles obtained in step ① into a muffle furnace, heat to 200-500° C., and keep warm for 0.5-5 hours to perform cracking treatment to obtain cracked resin;

[0031] ③ Soak the cracked resin obtained in step ② in an inorganic acid solution for 1 to 10 hours, then rinse with deionized water until neutral, dry to obtain a dry resin, and crush the dry resin to a particle size D50 of 2 to 20 μm to obtain a dry resin powder; the purpose of soaking with acid in this step is to remove residual iron, aluminum and a small amount of inorganic salts;

[0032] ④ Place the dry resin powder obtained in the step into an atmosphere furnace or a rotary kiln, heat it to 600-1500°C for carbonization treatment for 1-5 hours under nitrogen protection, cool it down, and discharge it to obtain a hard carbon negative electrode material.

[0033] The general resins of the present invention can be recycled and reused, especially resins containing benzene rings, such as polyaniline resins; or resins whose polymerized monomers are substituted by unsaturated bonds and will not be thermally decomposed at high temperatures have better data effects. Preferably, the type of the recycled waste resin is one or more of polyvinyl chloride resins, phenolic resins or polystyrene resins.

[0034] Preferably, the mass ratio of the recycled waste resin to the activator is 1:5-10.

[0035] Preferably, the concentration of concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, ferric chloride in dichloroethane solution, aluminum chloride in dichloroethane solution, oleum or chlorosulfonic acid is the highest concentration conventionally available on the market, such as the mass concentration of concentrated nitric acid is 65%, the mass concentration of concentrated phosphoric acid is 85%, the mass concentration of concentrated sulfuric acid is 98%, the mass concentration of ferric chloride in dichloroethane solution is 15-20%, the mass concentration of aluminum chloride in dichloroethane solution is 15-20%, the mass concentration of oleum is 105-115%, and the mass concentration of chlorosulfonic acid is above 95%.

[0036] Preferably, the inorganic acid solution is a hydrochloric acid solution, a sulfuric acid solution, or a nitric acid solution with a mass concentration of 2-8%.

[0037] Preferably, the temperature of the carbonization treatment is 900-1000° C., and the treatment time is 3-4 hours.

[0038] The present invention also includes the use of the hard carbon negative electrode material obtained by the above-mentioned method of preparing hard carbon negative electrode material using recycled waste resin in the preparation of lithium batteries, sodium batteries, potassium batteries and supercapacitors. The prepared hard carbon is used in the negative electrode material of sodium battery. The obtained battery has an energy density of more than 130wh / kg, and has good large current charging and discharging performance and cycle performance.

[0039] Example 1

[0040] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0041] The recycled waste polystyrene resin is washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are then immersed in concentrated sulfuric acid (mass concentration is 98%), stirred and heated to 50°C, kept warm for 1 hour, filtered, washed with water, and dried to obtain activated resin particles with sulfonic acid groups;

[0042] Step The activated resin particles obtained are placed in a muffle furnace, heated to 200° C., and kept at this temperature for 5 hours for cracking treatment to obtain cracked resin;

[0043] Step The obtained cracked resin was soaked in a 2% hydrochloric acid solution for 1 hour, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0044] The dry resin powder obtained in the step is placed in an atmosphere furnace, and under nitrogen protection, the temperature is raised to 600° C. for carbonization treatment for 5 hours, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0045] Example 2

[0046] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0047] The recycled waste polyvinyl chloride resin is washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are then immersed in 65% concentrated nitric acid, stirred and heated to 80°C, kept warm for 3 hours, filtered, washed with water, and dried to obtain activated resin particles with nitro groups;

[0048] Step The activated resin particles obtained are placed in a muffle furnace, heated to 500° C., and kept at this temperature for 0.5 hours to perform cracking treatment to obtain cracked resin;

[0049] Step The cracked resin was immersed in a 3% dilute sulfuric acid solution for 10 hours, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0050] The dry resin powder obtained in the step is placed in a rotary kiln, and under nitrogen protection, the temperature is raised to 1500° C. for carbonization treatment for 1 hour, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0051] Example 3

[0052] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0053] The recycled waste phenolic resin and polyvinyl chloride resin are washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are then immersed in concentrated phosphoric acid with a mass concentration of 85%, stirred and heated to 200°C, kept warm for 1 hour, filtered, washed with water, and dried to obtain activated resin particles with phosphate groups;

[0054] Step The activated resin particles obtained are placed in a muffle furnace, heated to 300°C, and kept at this temperature for 1 hour for cracking treatment to obtain cracked resin;

[0055] Step The cleaved resin was soaked in a nitric acid solution with a mass concentration of 8% for 2 hours, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0056] The dry resin powder obtained in the step is placed in a rotary kiln, and under nitrogen protection, the temperature is raised to 700° C. for carbonization treatment for 2 hours, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0057] Example 4

[0058] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0059] The recycled waste polyvinyl chloride resin and polystyrene resin are washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are then immersed in a dichloroethane solution of ferric chloride, stirred and heated to 50°C, kept warm for 5 hours, filtered, washed with water, and dried to obtain activated resin particles with chloroethyl; the mass concentration of the dichloroethane solution of ferric chloride is 15%;

[0060] Step The activated resin particles obtained are placed in a muffle furnace, heated to 400°C, and kept at this temperature for 3 hours for cracking treatment to obtain cracked resin;

[0061] Step The obtained cracked resin was soaked in a 6% hydrochloric acid solution for 5 hours, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0062] The dry resin powder obtained in the step is placed in an atmosphere furnace, and under the protection of nitrogen, the temperature is raised to 900° C. for carbonization treatment for 3 hours, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0063] Example 5

[0064] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0065] The recycled waste polystyrene resin and phenolic resin are washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are then immersed in activating agent chlorosulfonic acid, stirred and heated to 100°C, kept warm for 3 hours, filtered, washed with water, and dried to obtain activated resin particles with sulfonic acid groups;

[0066] Step The activated resin particles obtained are placed in a muffle furnace, heated to 450°C, and kept at this temperature for 1 hour for cracking treatment to obtain cracked resin;

[0067] Step The obtained cracked resin was soaked in a 4% dilute sulfuric acid solution for 1 to 10 hours, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0068] The dry resin powder obtained in the step is placed in a rotary kiln, and under nitrogen protection, the temperature is raised to 1000° C. for carbonization treatment for 2 hours, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0069] Example 6

[0070] A method for preparing a hard carbon negative electrode material by using recycled waste resin comprises the following steps:

[0071] The recycled waste phenolic resin is washed, dust, clay and other inorganic impurities are removed, and then crushed into particles, which are immersed in activating fuming sulfuric acid, stirred and heated to 120° C., kept warm for 2 hours, filtered, washed with water, and dried to obtain activated resin particles with sulfonic acid groups;

[0072] Step The activated resin particles obtained are placed in a muffle furnace, heated to 350°C, and kept at this temperature for 2 hours for cracking treatment to obtain cracked resin;

[0073] Step The cleaved resin was immersed in a hydrochloric acid solution with a mass concentration of 8% for 6 hours, then rinsed with deionized water until neutral, dried to obtain a dry resin, and crushed to a particle size of D 50 to 2~20μm to obtain dry resin powder;

[0074] The dry resin powder obtained in the step is placed in an atmosphere furnace or a rotary kiln, and under nitrogen protection, the temperature is raised to 900° C. for carbonization treatment for 4 hours, and the temperature is lowered to obtain a hard carbon negative electrode material.

[0075] The performance of the hard carbon negative electrode materials obtained in Examples 1 to 6 was tested, wherein the interlayer distance was tested using XRD (eg Figure 1 ), particle size D 50 The laser particle size analyzer was used for detection, and the gram capacity and first efficiency were tested by making button batteries for electrical performance detection. The results are shown in Table 1.

[0076] Table 1 Performance test results of hard carbon negative electrode materials obtained in Examples 1 to 6

[0077]

[0078] It can be seen from the results in Table 1 that the specific surface area of ​​the hard carbon negative electrode material obtained by the method of the present invention is 2-10m 2 / g, the specific surface area value is moderate, neither too large nor too small, because if the specific surface area is too large, it will affect the fluidity of the slurry, require more binder, and the first efficiency will be low; if the specific surface area is too small, the battery rate performance will be small; the interlayer distance is 0.37-0.40nm, the interlayer distance is the difference between hard carbon and graphite, the graphite interlayer distance is about 0.34nm, and the hard carbon is 0.37-0.40nm, the lithium ion radius is smaller than the sodium ion radius, and the lithium ion battery can use graphite as the negative electrode, but the sodium ion radius is larger, so only hard carbon materials can be used and graphite is not easy to use; the hard carbon negative electrode material obtained by the method of the present invention has a sodium-free gram capacity of more than 300 mAh / g, and the first efficiency exceeds 85%, the product performance is good, and it is made of Figure 2 It can be seen from the results that the hard carbon negative electrode material obtained by the method of the present invention has a regular particle size between 2-20um and a dense surface, which is conducive to the formation of a SEI film and can meet the application in the fields of lithium batteries, sodium batteries, potassium batteries, supercapacitors, etc., especially in sodium batteries.

Claims

1. A method for preparing a hard carbon negative electrode material by using recycled waste resin, characterized in that: The following steps are involved: ① Wash the recycled waste resin, remove dust and clay, and crush it into 10-100 mesh particles, soak it in the activator, heat it to above 50°C under stirring, keep it warm for 1-10 hours, filter, wash with water, and dry it to obtain activated resin particles; The activator is one of concentrated nitric acid, concentrated phosphoric acid, concentrated sulfuric acid, a dichloroethane solution of ferric chloride, a dichloroethane solution of aluminum chloride, oleum or chlorosulfonic acid; The type of the recycled waste resin is one or more of polyvinyl chloride resin or polystyrene resin; ② Place the activated resin particles obtained in step ① into a muffle furnace, heat to 200-500° C., and keep warm for 0.5-5 hours to perform cracking treatment to obtain cracked resin; ③ Soak the cracked resin obtained in step ② in an inorganic acid solution for 1 to 10 hours, then rinse with deionized water until neutral, dry to obtain a dry resin, and crush the dry resin into particles of D 50 to 2~20μm, and obtain dry resin powder; The inorganic acid solution is a hydrochloric acid solution, a sulfuric acid solution or a nitric acid solution with a mass concentration of 2-8%; ④Put the dry resin powder obtained in step ③ into an atmosphere furnace or a rotary kiln, heat it to 600-1500°C for carbonization treatment for 1-5 hours under nitrogen protection, cool it down, and discharge it to obtain a hard carbon negative electrode material.

2. The method for preparing hard carbon negative electrode material by using recycled waste resin according to claim 1, characterized in that: The mass ratio of recycled waste resin to activator is 1:5~10.

3. The method for preparing hard carbon negative electrode material by using recycled waste resin according to claim 1, characterized in that: The mass concentration of the concentrated phosphoric acid is 85%.

4. The method for preparing hard carbon negative electrode material by using recycled waste resin according to claim 1, characterized in that: The temperature of the carbonization treatment is 600~1000°C and the treatment time is 1~4 hours.

5. Use of the hard carbon negative electrode material obtained by the method for preparing hard carbon negative electrode material by recycling waste resin according to claim 1, characterized in that: Application in the preparation of lithium batteries, sodium batteries, potassium batteries and supercapacitors.

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