Method for manufacturing sodium ion battery by plastic waste closed-loop resource utilization

Abstract

The application provides a method for manufacturing a sodium ion battery by closed-loop resource utilization of plastic waste, comprising the following steps: S1, after pretreatment, the plastic waste is fully mixed with a catalyst, high-temperature sintering is performed, tail gas generated is absorbed by lye to form tail gas absorption liquid; S2, the product after high-temperature sintering is fully reacted with acid liquid, filtrate and filter residue are obtained by filtration, the filter residue is treated to obtain hard carbon, the filtrate and the tail gas absorption liquid are mixed at a certain ratio, spray drying is performed, and Na x TM y O2 is obtained by calcination; S3, Na x TM y O2 is used as a positive electrode material, hard carbon is used as a negative electrode material, the positive electrode and the negative electrode are matched, electrolyte is added, and a sodium ion battery is manufactured; the pyrolysis product, the tail gas absorption liquid and the catalyst are comprehensively utilized, waste plastic is converted into hard carbon material, and a sodium ion battery is constructed by using the sodium ion layered oxide positive electrode prepared based on the tail gas absorption liquid and the catalyst and the hard carbon negative electrode, so that the closed-loop recycling of plastic waste is realized.

Description

Technical Field

[0001] This invention belongs to the fields of environmental protection and electrochemical energy storage technology, specifically relating to a method for manufacturing sodium-ion batteries through closed-loop resource utilization of plastic waste. Background Technology

[0002] Recycling plastic waste is a complex undertaking, and researchers have been continuously seeking technically feasible and economically viable scientific methods. Co-pyrolysis of plastics can recover chemical energy from plastics, but the process is complex and requires significant external heating. Given that carbon is the main component of plastics, plastic waste can serve as a carbon source, producing value-added carbon-based products through carbonization. Many researchers have successfully converted plastics into carbon materials and are using these materials as electrodes for energy conversion and storage. Electrochemical energy, as an environmentally friendly energy source, has attracted considerable attention.

[0003] Therefore, in order to solve the problems of environmental pollution and resource waste caused by plastic waste and to find a method for efficient recycling of plastic waste, a method for manufacturing sodium-ion batteries through closed-loop resource utilization of plastic waste was designed. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for manufacturing sodium-ion batteries through closed-loop resource utilization of plastic waste. On the one hand, it can solve the problems of serious plastic waste pollution, immature existing recycling technology and high cost. On the other hand, it can catalytically crack plastic into hard carbon negative electrode material, and convert the catalyst and tail gas absorbent into positive electrode material to make sodium-ion batteries, thereby realizing the high-value utilization of plastics.

[0005] This invention is implemented as follows:

[0006] This invention provides a method for manufacturing sodium-ion batteries through closed-loop resource utilization of plastic waste, comprising the following steps:

[0007] S1. After pretreatment, plastic waste is thoroughly mixed with a catalyst of multi-element transition metal oxides and sintered at high temperature in an inert gas atmosphere. The exhaust gas generated during the high-temperature sintering process is absorbed by alkaline solution to form exhaust gas absorption liquid.

[0008] S2. The product after high-temperature sintering reacts fully with acid, and is filtered to obtain filtrate and filter residue. The filter residue is washed and dried to obtain hard carbon. The filtrate is mixed with the tail gas absorbent in a certain proportion and then spray-dried and calcined in air to obtain Na. x TM y O2;

[0009] S3. Put Na x TM yUsing O2 as the positive electrode material and hard carbon as the negative electrode material, by matching the positive and negative electrodes and adding electrolyte, a sodium-ion battery can be manufactured.

[0010] After pretreatment involving washing, drying, and crushing, plastic waste is mixed with a catalyst of multi-element transition metal oxides and sintered at high temperature. The organic polymers in the plastic waste undergo thermal decomposition, generating hard carbon during this process. While the carbon layers tend to grow in a planar direction, the cross-linking structure within the macromolecules hinders this planar growth. Therefore, the carbon layers cannot extend indefinitely to form a graphite-like layered structure; they only exhibit a stacked structure in the short term, remaining disordered in the long term. Some carbon layers accumulate disorderedly, resulting in defects and pores, forming the hard carbon structure. Hard carbon possesses a large number of micropores and a layered structure with a larger interlayer spacing than graphite, allowing for rapid insertion and extraction of sodium ions, resulting in excellent sodium storage performance and high rate capability.

[0011] The HCl, CO2, and other exhaust gases generated during sintering are absorbed by alkaline solution to form an exhaust gas absorbent. The multi-component transition metal oxide catalyst in the sintering product is reacted with acid and filtered to form a filtrate. The filtrate is mixed with the exhaust gas absorbent, spray-dried, and then calcined to obtain sodium ion layered oxide Na. x TM y O2, Na x TM y O2, as an electrode material, has advantages such as high specific capacity, ease of preparation, adjustable voltage, and low cost, making it well-suited for use in sodium-ion batteries. Multi-element transition metal oxides serve as catalysts for the thermal decomposition of plastic waste and also as catalysts for the preparation of Na+. x TM y This invention, starting with plastic waste, utilizes multi-element transition metal oxides to transform plastic waste into carbon-based materials. Carbon materials are used as electrodes for energy conversion and storage, with the prepared hard carbon serving as the negative electrode material. Na... x TM y O2 is used as the positive electrode material to assemble sodium-ion batteries.

[0012] Furthermore, the plastic waste includes one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, and acrylonitrile-butadiene-styrene copolymer.

[0013] Furthermore, the catalyst is two or more of nickel oxide, ferric oxide, manganese oxide, cobalt oxide, and copper oxide, and the mass ratio of plastic waste to catalyst is 5:1 to 1:1.

[0014] Furthermore, the molar ratio of the filtrate to the tail gas absorbent is 1:0.6 to 1:0.8.

[0015] Furthermore, Na x TM yIn O2, x is 0.6~0.8, y is 0.6~1, and TM is two or more of Ni, Fe, Mn, Co, and Cu.

[0016] Furthermore, the high-temperature sintering temperature is 400~800℃, and the sintering time is 1~3h.

[0017] Furthermore, the calcination temperature is 650~950℃, and the calcination time is 6~24h.

[0018] Furthermore, in step S3, Na... x TM y O2 is uniformly mixed with a conductive agent and a binder, and then coated onto aluminum foil to serve as the positive electrode; hard carbon is uniformly mixed with a conductive agent and a binder, and then coated onto aluminum foil to serve as the negative electrode; the conductive agent is Super P, and the binder is PVDF.

[0019] Furthermore, Na x TM y The mass ratio of O2, Super P, and PVDF is (5~9.5):(0.3~3):(0.2~2); the mass ratio of hard carbon, Super P, and PVDF is (5~9.5):(0.3~3):(0.2~2).

[0020] The present invention also provides a sodium-ion battery manufactured by the above method, wherein the sodium-ion battery is one of a button battery, a pouch battery, a square battery, or a cylindrical battery.

[0021] The present invention has the following beneficial effects:

[0022] 1. This invention comprehensively utilizes pyrolysis products, tail gas absorbent, and catalyst to transform waste plastics into hard carbon materials. A sodium-ion battery is constructed using a sodium-ion layered oxide positive electrode prepared based on the tail gas absorbent and catalyst, and a hard carbon negative electrode, thus achieving closed-loop recycling of plastic waste. This process can effectively reuse resources, solve the current problems of environmental pollution and low recycling rate of waste plastics, and has significant environmental and economic benefits, making it suitable for widespread promotion.

[0023] 2. This invention employs a novel process to convert waste plastics into hard carbon materials, which are then used as electrode materials for batteries. Compared with other methods for processing plastics in the prior art, this method has less environmental pollution and lower costs, and the sodium-ion batteries produced can be applied in the field of energy storage, realizing the high-value utilization of plastics. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a process flow diagram of the closed-loop resource utilization of plastic waste to manufacture sodium-ion batteries according to the present invention.

[0026] Figure 2 The images show the XRD patterns of hard carbon obtained by sintering at different temperatures and the Raman spectrum of hard carbon obtained by sintering at 700℃ in this invention.

[0027] Figure 3 The diagram shows the first-cycle charge-discharge performance and 700℃ cycling curve of the hard carbon half-cell in Example 1 of this invention.

[0028] Figure 4 Na obtained by sintering in Example 1 of this invention 0.67 Ni 0.2 Fe 0.2 Mn 0.6 XRD pattern of O2 material;

[0029] Figure 5 Na in Embodiment 1 of the present invention 0.67 Ni 0.2 Fe 0.2 Mn 0.6 O2 half-cell charge-discharge performance diagram and cycle curve;

[0030] Figure 6 The diagram shows the charge-discharge performance and cycle curve of the sodium-ion full battery in Example 1 of this invention.

[0031] Figure 7 Na obtained by sintering in Example 2 of this invention 0.67 Mn 0.69 Co 0.31 XRD pattern and charge-discharge performance diagram of O2 material;

[0032] Figure 8 Na obtained by sintering in Example 3 of this invention 0.7 Mn 0.9 Cu 0.1 XRD pattern and charge / discharge performance diagram of O2 material. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] The method for manufacturing sodium-ion batteries through closed-loop resource utilization of plastic waste in this embodiment is as follows: Figure 1 As shown, it includes the following steps:

[0036] 1. After washing, drying and crushing, plastic waste is thoroughly mixed with catalysts nickel oxide, manganese trioxide and ferric oxide. The mass ratio of plastic waste to catalyst is 5:2. High-temperature sintering is carried out under argon atmosphere. Sintering is carried out at 400℃, 500℃, 600℃, 700℃ and 800℃ for 1 hour respectively. The structure and performance are compared to determine the best hard carbon. The tail gas generated during the high-temperature sintering process is absorbed by NaOH solution to form tail gas absorption liquid.

[0037] 2. The product after high-temperature sintering reacts fully with nitric acid solution, and is filtered to obtain filtrate and filter residue. The filter residue is washed and dried to obtain hard carbon. The filtrate and tail gas absorption liquid are mixed at a ratio of 1:0.67, spray-dried, and calcined in air to obtain Na. 0.67 Ni 0.2 Fe 0.2 Mn 0.6 O2, wherein the calcination temperature is 900℃ and the calcination time is 24h;

[0038] 3. Put Na 0.67 Ni 0.2 Fe 0.2 Mn 0.6 O2, Super P, and PVDF are uniformly mixed in a mass ratio of 8:1:1 and coated onto aluminum foil to obtain Na. 0.67 Ni 0.2 Fe 0.2 Mn 0.6 O2 positive electrode; hard carbon, Super P, and PVDF are uniformly mixed in a mass ratio of 8:1:1 and coated onto aluminum foil to obtain the hard carbon negative electrode; Na... 0.67 Ni 0.2 Fe 0.2 Mn 0.6 A sodium-ion battery HC||Na was fabricated using an O2 positive electrode and a hard carbon negative electrode, with 1 mol / L NaClO4 (EC / DEC, volume ratio 1 / 1) as the electrolyte. 0.67 Ni 0.2 Fe0.2 Mn 0.6 O2, using HC||Na 0.67 Ni 0.2 Fe 0.2 Mn 0.6 Electrochemical tests were conducted on the O2 sodium ion full cell.

[0039] Example 2

[0040] Unlike Example 1, in this example, the catalyst used is manganese trioxide and cobalt trioxide, and the mass ratio of plastic waste to catalyst is 5:1. After calcination, Na is obtained. 0.67 Mn 0.69 Co 0.31 O2, wherein the calcination temperature is 700℃ and the calcination time is 6h, Na 0.67 Mn 0.69 Co 0.31 O2, Super P, and PVDF are uniformly mixed in a mass ratio of 7:2:1 and coated onto aluminum foil to obtain Na. 0.67 Mn 0.69 Co 0.31 O2 positive electrode, utilizing Na|| Na 0.67 Mn 0.69 Co 0.31 The electrochemical performance of the O2 half-cell was tested.

[0041] Example 3

[0042] Unlike Example 1, in this example, the catalyst used is manganese trioxide and copper oxide, the mass ratio of plastic waste to catalyst is 1:1, and the mixing ratio of filtrate to tail gas absorbent is 1:0.7. After calcination, Na is obtained. 0.7 Mn 0.9 Cu 0.1 O2, wherein the calcination temperature is 800℃ and the calcination time is 10h, Na 0.7 Mn 0.9 Cu 0.1 O2, Super P, and PVDF are uniformly mixed in a mass ratio of 5:3:2 and coated onto aluminum foil to obtain Na. 0.7 Mn 0.9 Cu 0.1 O2 positive electrode, utilizing Na||Na 0.7 Mn 0.9 Cu 0.1 The electrochemical performance of the O2 half-cell was tested.

[0043] Test case

[0044] The structure of the hard carbon obtained by sintering in Example 1 was analyzed, such as... Figure 2As shown in (a), it can be seen that the sintered products all correspond to the (002) and (100) characteristic diffraction peaks of hard carbon, so it can be determined that the sintered products are hard carbon; then Raman spectroscopy tests were performed on the hard carbon sintered at 700℃, as shown in (a). Figure 2 As shown in (b), after fitting the graph, the area ratio I of peak D to peak G is obtained. D / I G It is approximately 2.67, with a large degree of defect, easy electron conduction, and good electrode cycle efficiency.

[0045] Comparison of the properties of hard carbon sintered at different temperatures, such as Figure 3 As shown in (a), the hard carbon material sintered at 700℃ exhibits better charge-discharge performance, and 100 mA g -1 The discharge specific capacity is 180.56 mAh g. -1 It can achieve 86% of the first-week discharge specific capacity of commercial hard carbon (210 mAh g). -1 about), Figure 3 (b) Shows a discharge specific capacity of 152.22 mAh g after 160 cycles. -1 It exhibits minimal capacity decay and demonstrates good cycling performance.

[0046] Na obtained by sintering 0.67 Ni 0.2 Fe 0.2 Mn 0.6 O2 is used for structural testing, such as Figure 4 The XRD is shown in the figure.

[0047] Use 20 mA g for the first two weeks of battery assembly -1 Activated with a small current, followed by 100 mA g -1 Cyclic tests were performed on the current density, and the results are as follows: Figure 5 As shown, the specific capacity reached 104 mAh g in the first week. -1 During the cycling process, the average coulombic efficiency remained at around 99.53%, indicating good cycling performance. After matching the positive and negative electrodes, HC||Na was assembled. 0.67 Ni 0.2 Fe 0.2 Mn 0.6 Performance tests were conducted on the O2 sodium-ion full battery, and the results are as follows: Figure 6 As shown, the specific capacity reached 82.08 mAh g in the first week. -1 The average energy density is 125.64 Wh / kg. -1 During the cycle, the average coulombic efficiency remains at around 98.94%.

[0048] Na obtained in Example 2 0.67 Mn 0.69 Co 0.31O2 is used for structural testing, such as Figure 7 The XRD pattern is shown in (a). The battery was assembled, and the charge / discharge curves for the first two weeks are shown below. Figure 7 As shown in (b), the specific capacity reached 161.39 mAh g in the first week. -1 .

[0049] Na obtained in Example 3 0.7 Mn 0.9 Cu 0.1 O2 is used for structural testing, such as Figure 8 The XRD pattern is shown in (a). The battery was assembled, and the charge / discharge curves for the first two weeks are shown below. Figure 8 As shown in (b), the specific capacity reached 72.64 mAh g in the first week. -1 .

[0050] This invention comprehensively utilizes pyrolysis products, tail gas absorbent, and catalysts to transform waste plastics into hard carbon materials. A sodium-ion battery is constructed using a sodium-ion layered oxide cathode prepared based on the tail gas absorbent and catalyst, and a hard carbon anode, achieving closed-loop recycling of plastic waste. The resulting sodium-ion battery exhibits excellent electrochemical performance. This process effectively reuses resources, solving the current problems of environmental pollution and low recycling rates caused by waste plastics, demonstrating significant environmental and economic benefits, and is suitable for widespread application.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing sodium-ion batteries by closed-loop resource utilization of plastic waste, characterized in that, The method comprises the following steps: S1, the plastic waste is pretreated and mixed with a catalyst, the catalyst is a mixture of multiple transition metal oxides, high-temperature sintering is carried out in an inert gas atmosphere, and tail gas generated in the high-temperature sintering process is absorbed by a NaOH solution to form a tail gas absorption liquid; S2, the product after high-temperature sintering is fully reacted with acid liquor, filtrate and residue are obtained by filtration, the residue is washed and dried to obtain hard carbon, the filtrate is mixed with tail gas absorption liquid at a certain ratio, and then spray drying is carried out, and Na x TM y O2; S3, add Na x TM y O2 as a positive electrode material, hard carbon as a negative electrode material, match the positive electrode and the negative electrode, add electrolyte, and manufacture a sodium ion battery.

2. The method for manufacturing sodium ion battery from plastic waste closed-loop resource utilization according to claim 1, characterized in that: The plastic waste comprises one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, and acrylonitrile-butadiene-styrene copolymer.

3. The method for manufacturing sodium-ion battery from plastic waste closed-loop recycling according to claim 2, characterized in that: The catalyst is two or more of nickel oxide, diiron trioxide, dimanganese trioxide, dicobalt trioxide, and copper oxide, and the mass ratio of the plastic waste to the catalyst is 5:1-1:

1.

4. The method for manufacturing sodium-ion batteries from plastic waste closed-loop recycling according to claim 3, characterized in that: The mixing molar ratio of the filtrate to the tail gas absorption liquid is 1:0.6-1:0.

8.

5. The method for manufacturing sodium-ion battery from plastic waste closed-loop recycling according to claim 3, characterized in that: Na x TM y x is 0.6-0.8, y is 0.6-1, and TM is two or more of Ni, Fe, Mn, Co, and Cu.

6. The method for manufacturing sodium ion batteries by closed-loop resource utilization of plastic waste according to any one of claims 1-5, characterized in that: The high-temperature sintering temperature is 400-800 DEG C, and the sintering time is 1-3 h.

7. The method for manufacturing sodium ion batteries by closed-loop resource utilization of plastic waste according to any one of claims 1-5, characterized in that: The calcination temperature is 650-950 DEG C, and the calcination time is 6-24 h.

8. The method for manufacturing sodium-ion batteries from plastic waste closed-loop recycling according to claim 1, wherein: In step S3, Na x TM y O2 is uniformly mixed with a conductive agent and a binder, coated on an aluminum foil, and used as a positive electrode; and hard carbon is uniformly mixed with a conductive agent and a binder, coated on an aluminum foil, and used as a negative electrode; the conductive agent is Super P, and the binder is PVDF.

9. The method for manufacturing sodium-ion batteries from plastic waste closed-loop recycling according to claim 8, characterized in that: Na x TM y The mass ratio of O2, Super P, and PVDF is (5-9.5):(0.3-3):(0.2-2); the mass ratio of hard carbon, Super P, and PVDF is (5-9.5):(0.3-3):(0.2-2).

10. The sodium-ion battery prepared by the method of claim 1, wherein: The sodium ion battery is one of a button cell, a soft package battery, a square battery, or a cylindrical battery.

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