Preparation method of a porous carbon electrode material

Abstract

The present invention discloses a preparation method of a porous carbon electrode material, which relates to the technical field of porous carbon electrode materials. The porous carbon electrode material is obtained by reacting a copolymer monomer containing thioether and ferrocene obtained through a click reaction between a mercapto group and a vinyl group and a reduction reaction of a nitro group, polymerizing with an aniline monomer on the surface of modified MXene treated with a silane coupling agent and grafted with gallic acid ester to obtain modified polyaniline / MXene, and then wrapping the porous biochar with the modified polyaniline / MXene. The porous carbon electrode material of the present invention has excellent mass specific capacity, antioxidant property and cycling performance, and is worthy of popularization and use.

Description

Technical Field

[0001] The invention relates to the technical field of porous carbon electrode materials, and in particular to a method for preparing a porous carbon electrode material. Background Art

[0002] Porous carbon electrode materials made from biochar have been widely studied because of their large specific capacitance, good rate performance, and low resistance. However, the electrical conductivity and electrochemical activity of biochar are relatively low, and the porous carbon electrode materials made from biochar also have a volume effect during the ion insertion and migration process, resulting in insufficient cycle performance in long-term use, which limits the application and promotion of porous carbon electrode materials made from biochar.

[0003] Previous studies have used MXene materials to improve the volume effect of carbon-based electrode materials during use. However, MXene flakes are easy to accumulate and have poor antioxidant properties. Therefore, some researchers have used polyaniline to polymerize on the MXene surface to improve the antioxidant properties of MXene and prevent flake accumulation. However, polyaniline is easy to agglomerate due to the strong force between molecular chains, so its ability to improve the antioxidant properties of MXene is limited and needs to be improved urgently.

[0004] Therefore, a suitable modification method is needed to improve the agglomeration phenomenon of polyaniline and enhance the oxidation resistance of MXene / polyaniline materials. Then, the MXene / polyaniline materials can be applied to porous carbon electrode materials to improve the cycle performance of porous carbon electrode materials, thereby obtaining porous carbon electrode materials with excellent properties such as oxidation resistance and cycle performance. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for preparing a porous carbon electrode material.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A porous carbon electrode material, the preparation of which comprises the following steps:

[0008] Step S1, stirring vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine under ultraviolet light for 20-25 minutes to obtain a nitro product; adding the nitro product to toluene, heating to 45-50° C., starting reflux stirring, then adding sodium dithionite, and then reflux stirring for 1-1.5 hours to obtain a comonomer;

[0009] Further, the dosage ratio of vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine is 11 - 12 g : 8 - 9 g : 160 - 170 mL : 0.5 - 0.7 g, and the power of ultraviolet light is 100 - 150 W; the dosage ratio of the nitro product, toluene, and sodium dithionite is 19 - 21 g : 80 - 90 mL : 9 - 10 g;

[0010] During the reaction process of step S1, the terminal carbon-carbon double bond of vinylferrocene and the mercapto group of 2,6-bis(tert-butyl)-4-(mercaptomethyl)phenol undergo a click reaction under ultraviolet light irradiation to obtain a sulfur ether-containing nitro product; the nitro group of the nitro product is reduced to an amino group to obtain a comonomer;

[0011] Step S2: Add LiF to hydrochloric acid solution a and stir for 30 - 35 min, then add Ti3AlC2 powder, stir at 40 - 45 °C for 48 - 49 h, and then wash with hydrochloric acid solution b and distilled water until neutral, and vacuum freeze-dry for 12 - 13 h to obtain MXene; add MXene to ethanol and ultrasonically disperse for 1.5 - 2 h, then add a silane coupling agent, and stir and react at 55 - 65 °C for 18 - 20 h to obtain NH2-MXene; in an inert gas atmosphere, heat the gallate to 100 - 110 °C under reflux stirring, continue to stir at a constant temperature for 30 - 40 min, then cool to 55 - 60 °C and add methanol and NH2-MXene, and then add sodium methoxide, and stir and react for 24 - 26 h to obtain modified MXene;

[0012] Further, the dosage ratio of LiF, hydrochloric acid solution a, and Ti3AlC2 powder is 3.2 - 3.5 g : 40 - 45 mL : 1.5 - 2 g, the concentration of hydrochloric acid solution a is 9 - 9.5 mol / L, and the concentration of hydrochloric acid solution b is 1 - 1.5 mol / L; the dosage ratio of MXene, ethanol, and silane coupling agent is 0.5 - 1.0 g : 150 - 160 mL : 23 - 24 g, and the silane coupling agent is KH550; the dosage ratio of gallate, methanol, NH2-MXene, and sodium methoxide is 19 - 22 g : 100 - 120 mL : 10 - 11 g : 0.2 - 0.3 g, and the gallate is selected from one of methyl gallate, ethyl gallate, and propyl gallate;

[0013] During the reaction process of step S2, MXene is prepared by chemical etching, and the surface of MXene is treated with a silane coupling agent to obtain NH2-MXene; NH2-MXene undergoes an ammonolysis reaction with the gallate to introduce polyphenolic hydroxyl groups into MXene to obtain modified MXene;

[0014] Step S3: Add the modified MXene into hydrochloric acid solution c, stir for 8 - 10 min, add aniline, comonomer and cetyltrimethylammonium bromide, stir for 30 - 35 min, then dropwise add the hydrochloric acid solution of ammonium persulfate, stir for 8.5 - 9 h under ice bath, filter, wash, and dry in vacuum to obtain modified polyaniline / MXene;

[0015] Furthermore, the dosage ratio of the modified MXene, hydrochloric acid solution c, aniline, comonomer, cetyltrimethylammonium bromide, and the hydrochloric acid solution of ammonium persulfate is 0.3 - 0.35 g : 70 - 75 mL : 0.15 - 0.2 mL : 0.03 - 0.05 g : 0.2 - 0.25 g : 16 - 17 mL, and the concentration of hydrochloric acid solution c is 1 mol / L; the hydrochloric acid solution of ammonium persulfate is obtained by stirring and mixing 1 - 1.2 g of ammonium persulfate with 15 - 16 mL of hydrochloric acid solution c;

[0016] During the reaction process of Step S3, under the induction of ammonium persulfate and the surface functional groups of the modified MXene and the guidance of the template agent cetyltrimethylammonium bromide, aniline and the comonomer polymerize on the surface of the modified MXene to obtain modified polyaniline / MXene, which can prevent the restacking of MXene sheets;

[0017] Step S4: Wash the fruit peel, place it in an oven at 80 - 85 °C and dry for 6 - 7 h, crush it to obtain fruit peel powder for standby; pre - carbonize the fruit peel powder at 350 - 360 °C for 2.5 - 3 h, cool it and then sieve it through a 180 - 200 - mesh sieve to obtain pre - carbonized fruit peel powder; mix the pre - carbonized fruit peel powder, potassium hydroxide, and deionized water for 8 - 9 h, filter, dry at 95 - 100 °C for 4 - 5 h, then place it at 500 - 550 °C for 2 - 2.5 h, cool it to room temperature, wash it with acid solution until no bubbles are generated, filter, wash it with distilled water until neutral, and dry at 90 - 100 °C for 10 - 11 h to obtain porous biochar;

[0018] Furthermore, the dosage ratio of the pre - carbonized fruit peel powder, potassium hydroxide, and deionized water is 1 - 1.5 g : 2 - 3 g : 60 - 70 mL; the acid solution is a hydrochloric acid solution with a concentration of 1 - 1.5 mol / L;

[0019] During the reaction process of Step S4, potassium hydroxide is used to activate and create pores in the fruit wood powder to obtain porous biochar;

[0020] Step S5: Add modified polyaniline / MXene into deionized water, then ultrasonically disperse for 30 - 40 min, and then centrifuge for 1 - 1.5 h. Collect the supernatant to obtain a modified polyaniline / MXene suspension; Add porous biochar into ethanol and ultrasonically disperse for 35 - 45 min, then add the modified polyaniline / MXene suspension and stir for 4 - 4.5 h. After vacuum filtration, vacuum dry at 180 - 200 °C to obtain a porous carbon electrode material;

[0021] Further, the dosage ratio of modified polyaniline / MXene to deionized water is 1.4 - 1.6 g : 160 - 170 mL; the dosage ratio of porous biochar, ethanol, and the modified polyaniline / MXene suspension is 0.1 - 0.2 g : 20 - 30 mL : 55 - 65 mL; the volume fraction of ethanol is 95%;

[0022] During the reaction process of Step S5, hydrogen bonding occurs between the surface of modified polyaniline / MXene and porous biochar, thereby coating the modified polyaniline / MXene on the surface of porous biochar to obtain a porous carbon electrode material.

[0023] Advantages of the present invention: The present invention discloses a preparation method of a porous carbon electrode material. This preparation method involves obtaining a copolymer monomer containing thioether and ferrocene through a click reaction between a mercapto group and a vinyl group and a reduction reaction of a nitro group, and then performing a polymerization reaction on the surface of modified MXene treated with a silane coupling agent and grafted with gallic acid ester together with aniline monomer to obtain modified polyaniline / MXene. Then, the porous biochar is wrapped with the modified polyaniline / MXene to obtain a porous carbon electrode material.

[0024] The comonomer introduces thioether and ferrocene into the modified polyaniline. The ferrocene structure in the molecular chain of the modified polyaniline helps to promote the stretching of the molecular chain of the modified polyaniline, which not only improves the agglomeration phenomenon of the modified polyaniline and enhances the cycle performance of the electrode material containing the modified polyaniline; and ferrocene has good conductivity, which also helps to improve the conductivity of the electrode material containing the polyaniline-based material, thereby reducing the internal resistance of the prepared battery and enhancing the battery specific capacity; coating the modified polyaniline with improved agglomeration phenomenon on the surface of the modified MXene is more conducive to avoiding the self-stacking between the modified MXene sheets. The gallate introduced into the modified MXene has polyphenolic hydroxyl groups and has excellent antioxidant properties, reducing the oxidation tendency of the modified MXene, and producing a synergistic antioxidant effect with the thioether in the modified polyaniline, endowing the modified polyaniline / MXene with excellent antioxidant properties, thereby making the porous carbon electrode material have excellent antioxidant properties; coating the modified polyaniline / MXene on the surface of the porous biocarbon, the modified polyaniline / MXene formed by the modified polyaniline with improved agglomeration phenomenon and the modified MXene with enhanced antioxidant properties and strong flexibility also helps to improve the volume effect of the polyaniline-based and porous carbon-based electrode materials during the ion intercalation and deintercalation processes, thereby enhancing the cycle performance of the electrode material containing the modified polyaniline.

[0025] Therefore, the porous carbon electrode material of the present invention has excellent specific capacity, antioxidant properties and cycle performance, and is worthy of popularization and use. Detailed implementation manners

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] A porous carbon electrode material, the preparation of which comprises the following steps:

[0029] Step S1: Stir vinyl ferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine under ultraviolet light irradiation for 20 min to obtain a nitro product; add the nitro product to toluene, heat to 45 °C, start reflux stirring, then add sodium dithionite, and then reflux and stir for 1 h to obtain a comonomer; the dosage ratio of vinyl ferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine is 11 g: 8 g: 160 mL: 0.5 g, and the power of ultraviolet light is 100 W; the dosage ratio of the nitro product, toluene, and sodium dithionite is 19 g: 80 mL: 9 g;

[0030] Step S2: Add LiF to hydrochloric acid solution a and stir for 30 min. Then add Ti3AlC2 powder (supplier: Xinxi Technology, 200 mesh), stir at 40 °C for 48 h, wash with hydrochloric acid solution b and distilled water until neutral, and vacuum freeze-dry for 12 h to obtain MXene. Add MXene to ethanol and ultrasonically disperse for 1.5 h, then add KH550 and stir at 55 °C for 18 h to obtain NH2-MXene. In a nitrogen atmosphere, heat methyl gallate to 100 °C with reflux stirring, continue to stir at a constant temperature for 30 min, then cool to 55 °C, add methanol and NH2-MXene, then add sodium methoxide and stir for 24 h to obtain modified MXene. The dosage ratio of LiF, hydrochloric acid solution a, and Ti3AlC2 powder is 3.2 g: 40 mL: 1.5 g, the concentration of hydrochloric acid solution a is 9 mol / L, and the concentration of hydrochloric acid solution b is 1 mol / L. The dosage ratio of MXene, ethanol, and KH550 is 0.5 g: 150 mL: 23 g. The dosage ratio of methyl gallate, methanol, NH2-MXene, and sodium methoxide is 19 g: 100 mL: 10 g: 0.2 g;

[0031] Step S3: Add modified MXene to hydrochloric acid solution c, stir for 8 min, add aniline, comonomer, and cetyltrimethylammonium bromide, stir for 30 min, then dropwise add hydrochloric acid solution of ammonium persulfate, stir in an ice bath for 8.5 h, filter, wash, and vacuum dry to obtain modified polyaniline / MXene. The dosage ratio of modified MXene, hydrochloric acid solution c, aniline, comonomer, cetyltrimethylammonium bromide, and hydrochloric acid solution of ammonium persulfate is 0.3 g: 70 mL: 0.15 mL: 0.03 g: 0.2 g: 16 mL, and the concentration of hydrochloric acid solution c is 1 mol / L. The hydrochloric acid solution of ammonium persulfate is obtained by stirring and mixing 1 g of ammonium persulfate with 15 mL of hydrochloric acid solution c;

[0032] Step S4: Wash the fruit peel, place it in an oven at 80 °C and dry for 6 h, crush it to obtain fruit peel powder for standby. Pre-carbonize the fruit peel powder at 350 °C for 2.5 h, cool it, and sieve it through a 180-mesh sieve to obtain pre-carbonized fruit peel powder. Mix the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water for 8 h, filter, dry at 95 °C for 4 h, then place it at 500 °C for 2 h. After cooling to room temperature, wash it with acid solution until no bubbles are generated, filter, wash with distilled water until neutral, and dry at 90 °C for 10 h to obtain porous biochar. The dosage ratio of pre-carbonized fruit peel powder, potassium hydroxide, and deionized water is 1 g: 2 g: 60 mL. The acid solution is hydrochloric acid solution with a concentration of 1 mol / L;

[0033] Step S5: Add modified polyaniline / MXene to deionized water, then ultrasonically disperse for 30 min, then centrifuge for 1 h, and collect the supernatant to obtain a modified polyaniline / MXene suspension; add porous biochar to ethanol and ultrasonically disperse for 35 min, then add the modified polyaniline / MXene suspension, stir for 4 h, perform vacuum filtration, and then vacuum dry at 180 °C to obtain a porous carbon electrode material; the dosage ratio of modified polyaniline / MXene to deionized water is 1.4 g: 160 mL; the dosage ratio of porous biochar, ethanol, and modified polyaniline / MXene suspension is 0.1 g: 20 mL: 55 mL; the volume fraction of ethanol is 95%.

[0034] Example 2

[0035] A porous carbon electrode material, the preparation of which comprises the following steps:

[0036] Step S1: Stir vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine under ultraviolet light irradiation for 23 min to obtain a nitro product; add the nitro product to toluene, heat to 47 °C, start reflux stirring, then add sodium dithionite, and then reflux and stir for 1.3 h to obtain a comonomer; the dosage ratio of vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine is 11 g: 8 g: 165 mL: 0.6 g, and the power of ultraviolet light is 100 W; the dosage ratio of the nitro product, toluene, and sodium dithionite is 20 g: 85 mL: 9.5 g;

[0037] Step S2: Add LiF to hydrochloric acid solution a and stir for 33 min, then add Ti3AlC2 powder (supplier: Xinxi Technology, 200 mesh), stir at 43 °C for 48.5 h, then wash with hydrochloric acid solution b and distilled water until neutral, and vacuum freeze-dry for 12.5 h to obtain MXene; add MXene to ethanol and ultrasonically disperse for 1.7 h, then add KH550, stir and react at 60 °C for 19 h to obtain NH2-MXene; in a protective gas atmosphere, heat ethyl gallate to 105 °C under reflux stirring, continue to stir at a constant temperature for 35 min, then cool to 57 °C and add methanol and NH2-MXene, then add sodium methoxide, and stir and react for 25 h to obtain modified MXene; the dosage ratio of LiF, hydrochloric acid solution a, and Ti3AlC2 powder is 3.3 g: 42 mL: 1.8 g, the concentration of hydrochloric acid solution a is 9.3 mol / L, and the concentration of hydrochloric acid solution b is 1.3 mol / L; the dosage ratio of MXene, ethanol, and KH550 is 0.7: 155 mL: 23.5 g; the dosage ratio of ethyl gallate, methanol, NH2-MXene, and sodium methoxide is 20 g: 110 mL: 10.5 g: 0.25 g;

[0038] Step S3: Add the modified MXene into hydrochloric acid solution c, stir for 9 min, add aniline, comonomer and cetyltrimethylammonium bromide, stir for 33 min, then dropwise add the hydrochloric acid solution of ammonium persulfate, stir for 8.8 h under ice bath, filter, wash, and vacuum dry to obtain modified polyaniline / MXene; the dosage ratio of the modified MXene, hydrochloric acid solution c, aniline, comonomer, cetyltrimethylammonium bromide, and the hydrochloric acid solution of ammonium persulfate is 0.33 g: 73 mL: 0.17 mL: 0.04 g: 0.23 g: 16.5 mL, and the concentration of hydrochloric acid solution c is 1 mol / L; the hydrochloric acid solution of ammonium persulfate is obtained by stirring and mixing 1.1 g of ammonium persulfate with 15.5 mL of hydrochloric acid solution c.

[0039] Step S4: Wash the fruit peel, place it in an oven at 83 °C and dry for 6.5 h, crush it to obtain fruit peel powder for standby; pre-carbonize the fruit peel powder at 355 °C for 2.7 h, cool it and then pass through a 180-mesh sieve to obtain pre-carbonized fruit peel powder; mix the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water for 8.5 h, filter, dry at 95 °C for 4.5 h, then place it at 530 °C for 2.3 h, cool to room temperature, wash with acid solution until no bubbles are generated, filter, wash with distilled water until neutral, and dry at 95 °C for 10.5 h to obtain porous biochar; the dosage ratio of the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water is 1.3 g: 2.5 g: 65 mL; the acid solution is a hydrochloric acid solution with a concentration of 1.2 mol / L.

[0040] Step S5: Add the modified polyaniline / MXene into deionized water, then ultrasonically disperse for 35 min, then centrifuge for 1.3 h, collect the supernatant to obtain a modified polyaniline / MXene suspension; add the porous biochar into ethanol and ultrasonically disperse for 40 min, then add the modified polyaniline / MXene suspension, stir for 4.3 h, vacuum filter and then vacuum dry at 190 °C to obtain a porous carbon electrode material; the dosage ratio of the modified polyaniline / MXene and deionized water is 1.5 g: 165 mL; the dosage ratio of the porous biochar, ethanol, and the modified polyaniline / MXene suspension is 0.15 g: 25 mL: 60 mL; the volume fraction of ethanol is 95%.

[0041] Example 3

[0042] A porous carbon electrode material, the preparation of which comprises the following steps:

[0043] Step S1: Stir vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine under ultraviolet light irradiation for 25 min to obtain a nitro product; add the nitro product to toluene, heat up to 50 °C, start reflux stirring, then add sodium dithionite, and continue reflux stirring for 1.5 h to obtain a comonomer; the dosage ratio of vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine is 12 g: 9 g: 170 mL: 0.7 g, and the power of the ultraviolet light is 100 W; the dosage ratio of the nitro product, toluene, and sodium dithionite is 21 g: 90 mL: 10 g;

[0044] Step S2: Add LiF to hydrochloric acid solution a and stir for 35 min, then add Ti3AlC2 powder (supplier: Xinxi Technology, 200 mesh), stir at 45 °C for 49 h, and then wash with hydrochloric acid solution b and distilled water until neutral, and vacuum freeze-dry for 13 h to obtain MXene; add MXene to ethanol and ultrasonically disperse for 2 h, then add KH550, and stir at 65 °C for 20 h to obtain NH2-MXene; in a nitrogen atmosphere, heat propyl gallate to 110 °C under reflux stirring, continue to stir at a constant temperature for 40 min, then cool down to 60 °C and add methanol and NH2-MXene, and then add sodium methoxide, and stir for 26 h to obtain modified MXene; the dosage ratio of LiF, hydrochloric acid solution a, and Ti3AlC2 powder is 3.5 g: 45 mL: 2 g, the concentration of hydrochloric acid solution a is 9.5 mol / L, and the concentration of hydrochloric acid solution b is 1.5 mol / L; the dosage ratio of MXene, ethanol, and KH550 is 1.0 g: 160 mL: 24 g; the dosage ratio of propyl gallate, methanol, NH2-MXene, and sodium methoxide is 22 g: 120 mL: 11 g: 0.3 g;

[0045] Step S3: Add modified MXene to hydrochloric acid solution c, stir for 10 min, add aniline, comonomer, and cetyltrimethylammonium bromide, stir for 35 min, then dropwise add an ammonium persulfate hydrochloric acid solution, stir in an ice bath for 9 h, filter, wash, and vacuum dry to obtain modified polyaniline / MXene; the dosage ratio of modified MXene, hydrochloric acid solution c, aniline, comonomer, cetyltrimethylammonium bromide, and ammonium persulfate hydrochloric acid solution is 0.35 g: 75 mL: 0.2 mL: 0.05 g: 0.25 g: 17 mL, and the concentration of hydrochloric acid solution c is 1 mol / L; the ammonium persulfate hydrochloric acid solution is obtained by stirring and mixing 1.2 g of ammonium persulfate with 16 mL of hydrochloric acid solution c;

[0046] Step S4: Wash the fruit peels, place them in an oven at 85 °C for drying for 7 h, pulverize them to obtain fruit peel powder for standby; pre-carbonize the fruit peel powder at 360 °C for 3 h, cool it and then sieve it through a 180-mesh sieve to obtain pre-carbonized fruit peel powder; mix the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water for 9 h, filter, dry it at 100 °C for 5 h, then place it at 550 °C for 2.5 h, cool it to room temperature, wash it with acid solution until no bubbles are generated, filter, wash it with distilled water until neutral, and dry it at 100 °C for 11 h to obtain porous biochar; the dosage ratio of the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water is 1.5 g: 3 g: 70 mL; the acid solution is a hydrochloric acid solution with a concentration of 1.5 monl / L;

[0047] Step S5: Add the modified polyaniline / MXene to deionized water, then ultrasonically disperse it for 40 min, then centrifuge it for 1.5 h, collect the supernatant to obtain a modified polyaniline / MXene suspension; add the porous biochar to ethanol and ultrasonically disperse it for 45 min, then add the modified polyaniline / MXene suspension, stir for 4.5 h, vacuum filter it and then vacuum dry it at 200 °C to obtain a porous carbon electrode material; the dosage ratio of the modified polyaniline / MXene and deionized water is 1.6 g: 170 mL; the dosage ratio of the porous biochar, ethanol, and the modified polyaniline / MXene suspension is 0.2 g: 30 mL: 65 mL; the volume fraction of ethanol is 95%.

[0048] Comparative Example 1

[0049] Compared with Example 3, replace vinyl ferrocene with 1-hexene, and the rest are exactly the same as in Example 3 to prepare a porous carbon electrode material.

[0050] Comparative Example 2

[0051] Compared with Example 3, replace propyl gallate with methyl 3,5-di-tert-butyl-4-hydroxybenzoate, and the rest are exactly the same as in Example 3 to prepare a porous carbon electrode material.

[0052] Comparative Example 3

[0053] Compared with Example 3, replace the comonomer in Step S3 with aniline, and the rest are exactly the same as in Example 3 to prepare a porous carbon electrode material.

[0054] The following is a further effect detection of the porous carbon electrode material prepared by the present invention, and the detection results are as follows.

[0055] The porous carbon electrode material, conductive agent acetylene black, and binder PTFE were mixed at a mass ratio of 8:1:1. After adding absolute ethanol and stirring evenly, the mixture was heated and stirred in a 50°C water bath until it became paste-like, rolled into slices, pressed on the surface of nickel foam, and dried for electrochemical experiment tests. The electrochemical experiment was carried out in a 6 mol / L electrolyte solution, using a Pt mesh electrode as the counter electrode and Hg / HgO as the reference electrode. The mass specific capacity at a current density of 0.5 A / g was recorded in Table 1, and at the same time, the mass specific capacity retention rate after 10,000 charge-discharge cycles at a current density of 0.5 A / g was recorded in Table 1 to evaluate the cycling performance.

[0056] The porous carbon electrode material was placed in an air oven at 100°C for 7 days. Then, the mass specific capacity retention rate after oxidation was measured and recorded in Table 1 according to the above method to evaluate the antioxidant property.

[0057]

[0058] According to the data in Table 1, the porous carbon electrode material of the present invention has excellent mass specific capacity, antioxidant property, and cycling performance. Comparing Example 3 with Comparative Example 1, it can be seen that when vinyl ferrocene was replaced with 1-hexene and ferrocene was not introduced into the modified polyaniline, the mass specific capacity of the electrode material decreased, which could not promote the stretching of the molecular chain of the modified polyaniline, nor could it improve the agglomeration phenomenon of the modified polyaniline. The cycling performance of the electrode material decreased, and the mass specific capacity retention rate of the electrode material decreased. It was also not conducive to improving the conductivity of the electrode material containing polyaniline-based, thus reducing the mass specific capacity of the battery. Comparing Example 3 with Comparative Example 2, it can be seen that when gallate was replaced with hindered phenol and polyhydric phenolic hydroxyl groups were not introduced, the antioxidant property of the modified MXene decreased, and the synergistic antioxidant property with the thioether in the modified polyaniline coated on the MXene weakened. As a result, the ability of the modified MXene in the electrode material to improve the volume effect during the ion intercalation and deintercalation processes of the polyaniline-based and porous carbon-based electrode materials decreased due to the decrease in antioxidant property, thereby resulting in a decrease in the mass specific capacity retention rate of the porous carbon electrode material after oxidation. Comparing Example 3 with Comparative Example 3, it can be seen that when the comonomer was replaced with aniline and thioether was not introduced into the polyaniline, it could not form a synergistic effect with the gallate in the modified MXene, the antioxidant property of the electrode material decreased, and ferrocene was not introduced into the polyaniline. The mass specific capacity of the electrode material decreased, which could not promote the stretching of the molecular chain of the modified polyaniline and could not improve the agglomeration phenomenon of the modified polyaniline. As a result, the cycling performance of the electrode material decreased, and the mass specific capacity retention rate of the electrode material decreased.

[0059] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications, supplements, or use similar methods of substitution to the described specific embodiments. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they shall fall within the protection scope of the present invention.

Claims

1. A preparation method of a porous carbon electrode material, characterized in that: It includes the following steps: Step S1: Stir vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine under ultraviolet light irradiation to obtain a nitro product; add the nitro product to toluene, then add sodium dithionite, and stir to react to obtain a comonomer; Step S2: Add LiF to hydrochloric acid solution a and stir for 30 - 35 min, then add Ti3AlC2 powder, stir at 40 - 45 °C for 48 - 49 h, wash with hydrochloric acid solution b and distilled water respectively until neutral, and vacuum freeze-dry for 12 - 13 h to obtain MXene; add MXene to ethanol and ultrasonically disperse for 1.5 - 2 h, then add a silane coupling agent, stir and react at 55 - 65 °C for 18 - 20 h to obtain NH2-MXene; in a protective gas atmosphere, heat gallate to 100 - 110 °C under reflux stirring, continue to stir at a constant temperature for 30 - 40 min, then cool to 55 - 60 °C and add methanol and NH2-MXene, then add sodium methoxide, stir and react for 24 - 26 h to obtain modified MXene; Step S3: Add modified MXene to hydrochloric acid solution c, add aniline, the comonomer, and cetyltrimethylammonium bromide, stir, and then dropwise add a hydrochloric acid solution of ammonium persulfate, and stir to obtain modified polyaniline / MXene; Step S4: Wash the fruit peel, dry it, and crush it to obtain fruit peel powder for standby; pre-carbonize and sieve the fruit peel powder to obtain pre-carbonized fruit peel powder; mix the pre-carbonized fruit peel powder, potassium hydroxide, and deionized water, and then perform carbonization and acid solution post-treatment to obtain porous biochar; Step S5: Add modified polyaniline / MXene to deionized water, ultrasonically disperse and centrifuge, and collect the supernatant to obtain a modified polyaniline / MXene suspension; add the porous biochar to ethanol, ultrasonically disperse it, and then add it to the modified polyaniline / MXene suspension, and stir to obtain a porous carbon electrode material.

2. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S1, the dosage ratio of vinylferrocene, 4-nitrobenzenethiol, DMF, and 4-dimethylaminopyridine is 11 - 12 g : 8 - 9 g : 160 - 170 mL : 0.5 - 0.7 g.

3. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S1, the power of ultraviolet light is 100 - 150 W; the dosage ratio of the nitro product, toluene, and sodium dithionite is 19 - 21 g : 80 - 90 mL : 9 - 10 g.

4. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S2, the dosage ratio of LiF, hydrochloric acid solution a, and Ti3AlC2 powder is 3.2 - 3.5 g : 40 - 45 mL : 1.5 - 2 g, the concentration of hydrochloric acid solution a is 9 - 9.5 mol / L, and the concentration of hydrochloric acid solution b is 1 - 1.5 mol / L.

5. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S2, the dosage ratio of MXene, ethanol, and the silane coupling agent is 0.5 - 1.0 g : 150 - 160 mL : 23 - 24 g, and the silane coupling agent is KH550.

6. The preparation method of a porous carbon electrode material according to claim 1, wherein: In step S2, the dosage ratio of gallate, methanol, NH2-MXene, and sodium methoxide is 19 - 22 g : 100 - 120 mL : 10 - 11 g : 0.2 - 0.3 g, and the gallate is selected from one of methyl gallate, ethyl gallate, and propyl gallate.

7. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S3, the dosage ratio of the modified MXene, hydrochloric acid solution c, aniline, comonomer, cetyltrimethylammonium bromide, and ammonium persulfate hydrochloric acid solution is 0.3 - 0.35 g : 70 - 75 mL : 0.15 - 0.2 mL : 0.03 - 0.05 g : 0.2 - 0.25 g : 16 - 17 mL.

8. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S3, the concentration of hydrochloric acid solution c is 1 mol / L; the ammonium persulfate hydrochloric acid solution is obtained by stirring and mixing 1 - 1.2 g of ammonium persulfate with 15 - 16 mL of hydrochloric acid solution c.

9. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S4, the dosage ratio of the pre-carbonized peel powder, potassium hydroxide, and deionized water is 1 - 1.5 g : 2 - 3 g : 60 - 70 mL; the acid solution is a hydrochloric acid solution with a concentration of 1 - 1.5 monl / L.

10. The preparation method of a porous carbon electrode material according to claim 1, characterized in that: In step S5, the dosage ratio of the modified polyaniline / MXene and deionized water is 1.4 - 1.6 g : 160 - 170 mL; the dosage ratio of the porous biochar, ethanol, and the modified polyaniline / MXene suspension is 0.1 - 0.2 g : 20 - 30 mL : 55 - 65 mL; the volume fraction of ethanol is 95% in all cases.

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