Natural poultry manure modified biomass-derived hard carbon negative electrode material and preparation method and application thereof

Abstract

The present application relates to the technical field of sodium ion battery negative electrode material, and particularly relates to a natural poultry manure modified biomass-derived hard carbon negative electrode material and a preparation method and application thereof.The preparation method comprises the following steps: drying, crushing and pre-oxidizing a biomass raw material to obtain a hard carbon precursor; mixing the hard carbon precursor with poultry manure to obtain a modified precursor, carbonizing the modified precursor to obtain modified pyrolytic hard carbon; and post-treating the modified pyrolytic hard carbon to obtain a natural poultry manure modified biomass-derived hard carbon negative electrode material.The present application utilizes the natural poultry manure rich in N, P and S elements to dope heteroatoms into high-temperature pyrolytic hard carbon, and the prepared biomass-derived hard carbon negative electrode material has high first coulomb efficiency and excellent rate performance, and has great application prospect.

Description

Technical Field

[0001] This invention relates to the field of sodium-ion battery anode material technology, and in particular to a biomass-derived hard carbon anode material modified from natural poultry manure, its preparation method, and its application. Background Technology

[0002] The key to developing sodium-ion batteries lies in developing high-performance electrode materials. Hard carbon, due to its low voltage plateau and high sodium storage capacity, is an ideal commercially viable anode material for sodium-ion batteries. Among various hard carbon raw materials, biomass materials, with their cellulose, hemicellulose, and lignin components forming rich porous structures during pyrolysis, produce hard carbon with excellent sodium storage capacity. Furthermore, their wide availability and low cost have led to extensive research in recent years. Although most cellulosic biomass-derived hard carbons currently exhibit high reversible capacity, their initial efficiency is only around 85%, and their rate performance is also poor, hindering further expansion of their applications. Therefore, there is an urgent need to develop low-cost modification strategies for biomass-derived hard carbon. Summary of the Invention

[0003] Based on this, the purpose of this invention is to provide a biomass-derived hard carbon anode material modified with natural poultry manure, its preparation method, and its application. By using natural poultry manure rich in N, P, and S elements to dope high-temperature pyrolysis hard carbon with heteroatoms, the prepared biomass-derived hard carbon anode material has high initial coulombic efficiency and excellent rate performance, and has great application prospects.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This invention first provides a method for preparing a biomass-derived hard carbon anode material modified from natural poultry manure, which includes the following steps: S1. Dry, pulverize and pre-oxidize the biomass raw material to obtain a hard carbon precursor; S2. The hard carbon precursor is mixed with poultry manure to obtain a modified precursor, and the modified precursor is carbonized to obtain modified pyrolytic hard carbon. S3. The modified pyrolytic hard carbon is further processed to obtain a biomass-derived hard carbon anode material modified from natural poultry manure.

[0005] As a further improvement to the above-mentioned solution of the present invention, in step S1, the biomass raw material is at least one of bamboo powder, peanut shell, coconut shell, sugarcane bagasse, and straw.

[0006] As a further improvement to the above-mentioned solution of the present invention, in step S1, the pre-oxidation treatment is carried out at 200-400°C for 2-8 hours in an air or oxygen atmosphere.

[0007] As a further improvement to the above-mentioned solution of the present invention, in step S2, the poultry manure is at least one of chicken manure, pigeon manure, and duck manure, and the water content of the poultry manure is 5-10%.

[0008] As a further improvement to the above-mentioned scheme of the present invention, in step S2, the mass of poultry manure in the modified precursor is 2%-10% of the mass of the hard carbon precursor.

[0009] As a further improvement to the above-mentioned solution of the present invention, in step S2, the carbonization is carried out under a protective atmosphere, with the temperature increased to 1000-1400°C at a heating rate of 2-10°C / min and held for 1-4 hours.

[0010] As a further improvement to the above-mentioned solution of the present invention, in step S3, the post-processing includes acid washing and purification, washing, and drying in sequence.

[0011] As a further improvement to the above-mentioned solution of the present invention, the acid washing and purification involves adding the modified pyrolytic hard carbon to an acid solution to obtain a mixture, and stirring the mixture for 2-12 hours; in the mixture, the mass percentage of the modified pyrolytic hard carbon is 10%-30%, and the acid solution is at least one of dilute hydrochloric acid, dilute sulfuric acid, and dilute nitric acid; the washing involves washing 5-10 times with deionized water or distilled water.

[0012] The present invention also provides a biomass-derived hard carbon anode material modified from natural poultry manure, which is prepared by the preparation method described above.

[0013] The present invention also provides an application of a biomass-derived hard carbon anode material modified from natural poultry manure, prepared by the method described above, in a sodium-ion battery.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes natural poultry manure rich in N, P, and S elements to dope high-temperature pyrolytic hard carbon with heteroatoms. Nitrogen doping improves electronic conductivity; phosphorus doping widens the interlayer spacing, facilitating sodium ion insertion / extraction; sulfur doping introduces abundant active sites and defects on the hard carbon surface, promoting the storage of more sodium ions through surface adsorption mechanisms and contributing additional slope capacity. The biomass-derived hard carbon anode material prepared by this invention has a conductivity of 0.05 A g. -1 The initial coulombic efficiency at current density is ≥89%, and the first-cycle reversible capacity is ≥380 mAh / g at 5A g. -1 It still has a discharge capacity of 200 mAh / g even at a high current density.

[0015] The modified hard carbon anode material of this invention has a wide range of raw material sources and low prices. Both the raw materials and the modified materials are natural products that are pollution-free and have very low costs. Moreover, the process for preparing hard carbon is simple and easy to promote. The modification strategy can effectively control the structure of the hard carbon anode material, improve its first coulombic efficiency and reversible capacity, and improve its rate performance. Attached Figure Description

[0016] Figure 1 The biomass-derived hard carbon anode materials prepared for Example 1 and Comparative Examples 1-3 were used in 0.05 A g. -1 First-cycle charge-discharge curves at current density; Figure 2 The graph shows a comparison of the rate performance of the biomass-derived hard carbon anode materials prepared in Example 1 and Comparative Examples 1-3 at different current densities. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0019] Example 1 This embodiment proposes a biomass-derived hard carbon anode material modified from natural poultry manure, the preparation method of which includes the following steps: (1) Take 10g of bamboo powder and dry it in an oven at 80°C for 12h. Then, use a pulverizer to further pulverize it through a 200-mesh sieve. Put the sieved fine bamboo powder into a muffle furnace for pre-oxidation treatment in air: heat it to 300°C at a heating rate of 5°C / min and keep it at that temperature for 3h. Then, cool it naturally to room temperature to obtain a hard carbon precursor.

[0020] (2) The hard carbon precursor prepared in step (1) is mixed with 6 wt% of dry chicken manure (8% moisture content), ground thoroughly, transferred into a tube furnace and nitrogen gas is introduced. The temperature is raised to 1400 ℃ at a heating rate of 5℃ / min and held for 3 hours. The mixture is then naturally cooled to room temperature to obtain modified pyrolytic hard carbon.

[0021] (3) The modified pyrolytic hard carbon prepared in step (2) is added to 60 mL of 1 M dilute hydrochloric acid, stirred for 8 h, washed 5 times with distilled water until pH=7, and then dried to obtain the modified hard carbon anode material.

[0022] Example 2 This embodiment proposes a biomass-derived hard carbon anode material modified from natural poultry manure, the preparation method of which includes the following steps: (1) Take 10g of peanut shells and dry them in an oven at 80°C for 12h. Then, further crush them through a 200-mesh sieve using a pulverizer. Place the sieved fine bamboo powder into a muffle furnace for pre-oxidation treatment in air: heat it to 200°C at a heating rate of 5°C / min and keep it at that temperature for 8h. Then, cool it naturally to room temperature to obtain a hard carbon precursor.

[0023] (2) The hard carbon precursor prepared in step (1) is mixed with 4 wt% of dried pigeon droppings (5% water content), ground thoroughly, transferred into a tube furnace and then a nitrogen atmosphere is introduced. The temperature is raised to 1000 ℃ at a heating rate of 5 ℃ / min and held for 4 h. The mixture is then naturally cooled to room temperature to obtain modified pyrolytic hard carbon.

[0024] (3) The modified pyrolytic hard carbon prepared in step (2) is added to 60 mL of 1 M dilute hydrochloric acid, stirred for 8 h, washed 5 times with distilled water until pH=7, and then dried to obtain the modified hard carbon anode material.

[0025] Example 3 This embodiment proposes a biomass-derived hard carbon anode material modified from natural poultry manure, the preparation method of which includes the following steps: (1) Take 10g of straw and dry it in an oven at 80°C for 12h. Then, use a pulverizer to further pulverize it through a 200-mesh sieve. Put the sieved fine bamboo powder into a muffle furnace for pre-oxidation treatment in air: heat it to 400°C at a heating rate of 5°C / min and keep it at that temperature for 2h. Then, cool it naturally to room temperature to obtain a hard carbon precursor.

[0026] (2) The hard carbon precursor prepared in step (1) is mixed with 8 wt% of dry duck manure (moisture content of 10%), ground thoroughly, transferred into a tube furnace and then a nitrogen atmosphere is introduced. The temperature is raised to 1200 ℃ at a heating rate of 5℃ / min and held for 3h. The mixture is then naturally cooled to room temperature to obtain modified pyrolytic hard carbon.

[0027] (3) The modified pyrolytic hard carbon prepared in step (2) is added to 60 mL of 1 M dilute hydrochloric acid, stirred for 8 h, washed 5 times with distilled water until pH=7, and then dried to obtain the modified hard carbon anode material.

[0028] Comparative Example 1 The difference between this comparative example and Example 1 is that dried chicken manure was not added in step (2) of this comparative example.

[0029] Comparative Example 2 The difference between this comparative example and Example 1 is that the amount of dried chicken manure added in step (2) of this comparative example is 0.5 wt% of the hard carbon precursor.

[0030] Comparative Example 3 The difference between this comparative example and Example 1 is that the amount of dried chicken manure added in step (2) of this comparative example accounts for 12 wt% of the hard carbon precursor.

[0031] Test case The hard carbon anode materials prepared in Examples 1 and Comparative Examples 1-3 were used to prepare sodium-ion batteries: the hard carbon prepared in Examples 1 and Comparative Examples 1-3, the conductive agent Super P, and sodium carboxymethyl cellulose (CMC) were mixed evenly in ultrapure water at a mass ratio of 9:0.5:0.5, and then coated onto copper foil. After air drying, the mixture was dried at 80 °C for 10 h to obtain the desired anode sheet. In a glove box (O2 and H2O < 0.1 ppm), CR2032 coin cells were assembled using the anode sheets prepared in Examples 1 and Comparative Examples 1-3 as the working electrode, the positive electrode as a sodium metal sheet, and the separator as a glass fiber.

[0032] The electrochemical performance of each prepared sodium-ion battery was tested, and the results are as follows: Figure 1 , Figure 2 As shown.

[0033] Figure 1 Sodium-ion batteries prepared using the hard carbon anode materials of Example 1 and Comparative Examples 1-3 were tested at 0.1 A g. -1 The first charge-discharge curve at current density, from Figure 1 It can be seen that, compared with Comparative Example 1, the first coulombic efficiency and reversible capacity of the modified biomass-derived hard carbon in Example 1 are greatly improved through the synergistic effect of various heteroatoms in poultry manure. However, when the poultry manure modifier is insufficient, the first coulombic efficiency and reversible capacity of the biomass-derived hard carbon in Comparative Example 2 are almost the same as those in Comparative Example 1 without modifier, with almost no improvement. When the poultry manure modifier is excessive, the capacity in Comparative Example 3 decreases significantly because the main components of poultry manure are organic matter, uric acid, and minerals, and excessive addition does not benefit the carbonization of biomass.

[0034] Figure 2 To determine the discharge capacity of sodium-ion batteries prepared using the hard carbon anode materials of Example 1 and Comparative Examples 1-3, from... Figure 2 It can be seen that the rate performance of the modified biomass-derived hard carbon in Example 1 was also improved, at 5 A g -1The discharge capacity of 200 mAh / g is still maintained even at a high current density. This is due to the introduction of abundant active sites and defects on the surface, which can promote the storage of more sodium ions through surface adsorption mechanism. The increased interlayer spacing is conducive to sodium ion insertion and extraction, and the electronic conductivity is also greatly improved. However, when the amount of poultry manure modifier used in Comparative Example 2 is small, the effect on improving the electrical performance of biomass-derived hard carbon anode material is relatively weak. When the amount of poultry manure modifier used in Comparative Example 3 is excessive, it has a negative effect on the electrical performance of biomass-derived hard carbon anode material. This is because excessive poultry manure will cause the generation of impurities and damage the carbon structure. Therefore, the optimal amount of poultry manure modifier is between 2wt% and 10wt%.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a biomass-derived hard carbon anode material modified from natural poultry manure, characterized in that, It includes the following steps: S1. The biomass raw material is dried, pulverized and pre-oxidized to obtain a hard carbon precursor; the biomass raw material is at least one of bamboo powder, peanut shell, coconut shell, sugarcane bagasse and straw; the pre-oxidation treatment is carried out in an air or oxygen atmosphere at 200-400℃ for 2-8 hours. S2. The hard carbon precursor is mixed with poultry manure rich in N, P and S elements to obtain a modified precursor, and the modified precursor is carbonized to obtain modified pyrolytic hard carbon. The poultry manure is at least one of chicken manure, pigeon manure, and duck manure, and the moisture content of the poultry manure is 5-10%; in the modified precursor, the mass of the poultry manure is 2%-10% of the mass of the hard carbon precursor; the carbonization is carried out under a protective atmosphere, with a heating rate of 2-10℃ / min to 1000-1400℃ and held at that temperature for 1-4 hours. S3. The modified pyrolytic hard carbon is further processed to obtain a biomass-derived hard carbon anode material modified from natural poultry manure.

2. The method for preparing biomass-derived hard carbon anode material modified from natural poultry manure according to claim 1, characterized in that, In step S3, the post-processing includes acid washing and purification, washing, and drying in sequence.

3. The method for preparing biomass-derived hard carbon anode material modified from natural poultry manure according to claim 2, characterized in that, The acid washing purification involves adding the modified pyrolytic hard carbon to an acid solution to obtain a mixture, which is then stirred for 2-12 hours. In the mixture, the modified pyrolytic hard carbon accounts for 10%-30% of the mass, and the acid solution is at least one of dilute hydrochloric acid, dilute sulfuric acid, and dilute nitric acid, with a concentration of 0.5-2M. The washing process involves washing 5-10 times with deionized water or distilled water.

4. A biomass-derived hard carbon anode material modified from natural poultry manure, characterized in that, It is prepared by the preparation method described in any one of claims 1-3.

5. The application of a biomass-derived hard carbon anode material modified with natural poultry manure, prepared by any one of claims 1-3, in sodium-ion batteries.

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