A method for preparing an electrode material based on MXene

Abstract

The invention discloses a method for preparing an electrode material based on MXene, and the preparation steps are as follows: 1) using aluminum carbide Ti3AlC2, hydrochloric acid HCl, and lithium fluoride LiF to synthesize a two-dimensional material Ti3C2Tx, called MXene, by etching, wherein the MXene is a nanosheet with a thickness of 1-2 nm and a lateral size of 100-600 nm. 2) dispersing the MXene in step 1) in ethanolamine or a water / ethanolamine solution, ultrasonicating at low temperature, adding tetrahydrated manganese chloride MnCl2·4H2O to dissolve, then adding selenium powder Se and sodium borohydride NaBH4, stirring, heating at 175°C to 185°C for 11 to 13 hours, cooling to room temperature after the reaction is completed, collecting the product, washing with deionized water, and freeze-drying to obtain a powder product; the feed mass of the MXene is 15 to 60 mg, the molar ratio of Se to MnCl2·4H2O is 1:1, and the volume of ethanolamine to water is 5:0 to 2:3. The electrode material prepared by this method has high specific capacitance, long charge and discharge time, good weight-to-capacitance performance and good rate performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrode material preparation, and in particular relates to a method for preparing an electrode material based on MXene. Background Art

[0002] Supercapacitors, also known as electrochemical capacitors, store energy through ion adsorption or redox reactions. Supercapacitors have low energy density but high power density, which means that they can achieve higher output or absorption power in a shorter time. Therefore, in some applications that require high power output, fast charging and discharging, and ultra-long cycle life, such as power grid regulation systems, start-stop devices for electric vehicles, etc., supercapacitors can be used as a supplement or even a substitute for batteries. The earliest supercapacitor patent was applied by General Motors in 1957, which opened the precedent for the development of supercapacitors. It was not until the 1980s that supercapacitors were industrialized and attracted the attention of all sectors of society. In the entire electrochemical energy storage system, supercapacitors are a new type of electrochemical energy storage device, whose performance is between ordinary capacitors and batteries, combining the advantages of both, and have many irreplaceable advantages: ① High power density. Supercapacitors have a high power density, which means that they can achieve fast charge transfer, so they have excellent large current charging and discharging capabilities, and can complete the charging and discharging process in a few seconds. ② Long cycle life. The charging and discharging process of supercapacitors is highly reversible, especially double-layer supercapacitors, so they have excellent cycle life. ③ Wide operating temperature range. The increase or decrease in temperature has little effect on the ion adsorption and desorption process, resulting in little loss in device performance. Therefore, the supercapacitor has a wide operating temperature range and has excellent high-temperature performance. ④ Long shelf time. Supercapacitors can be placed for a long time without affecting performance and can be restored to their initial state only by charging. ⑤ High safety performance and green environmental protection. However, flexible supercapacitors still have problems such as low energy density and small voltage window, which seriously limit their large-scale application. The electrochemical properties of flexible supercapacitors are mainly determined by flexible electrodes. Therefore, studying flexible electrodes with high specific capacitance and wide voltage window is a top priority in the field of flexible supercapacitor research. Summary of the invention

[0003] In view of this, the present invention provides a method for preparing an electrode material based on MXene. The present invention specifically provides the following technical solution: a method for preparing an electrode material based on MXene, the preparation steps are as follows:

[0004] 1) A two-dimensional material Ti3C2Tx, called MXene, is synthesized by etching aluminum titanium carbide Ti3AlC2, hydrochloric acid HCl, and lithium fluoride LiF. The MXene is a nanosheet with a thickness of 1-2 nm and a lateral size of 100-600 nm.

[0005] 2) dispersing the MXene prepared in step 1) in ethanolamine or water / ethanolamine solution, sonicating at low temperature, adding manganese chloride tetrahydrate MnCl2·4H2O to dissolve, then adding selenium powder Se and sodium borohydride NaBH4, stirring, heating at 175°C to 185°C for 11 to 13 hours, cooling to room temperature after the reaction, collecting the product, washing with deionized water, and freeze-drying to obtain a powder product;

[0006] The feed mass of the MXene is 15-60 mg, the molar ratio of Se and MnCl2·4H2O is 1:1, and the volume of ethanolamine and water is 5:0-2:3.

[0007] Furthermore, the feed mass of MXene is 30-45 mg, and the volume ratio of ethanolamine to water is 4:1-3:2.

[0008] Furthermore, the feed mass of MXene was 45 mg, and the volume ratio of ethanolamine to water was 3:2.

[0009] Further, step 1) is specifically as follows: dissolving Ti3AlC2 powder in a mixed solution of HCl and LiF, stirring the reaction at 30°C to 40°C for 23 to 25 hours, then centrifuging the solution, washing until the pH reaches neutrality, obtaining Ti3C2Tx after centrifugation, dispersing it in deionized water, and performing ultrasonic stripping while passing an inert gas. The Ti3C2Tx solution after ultrasonic stripping is centrifuged at 3000rpm to 4000rpm for 1 to 1.5 hours, and the supernatant collected is the Ti3C2TX nanosheet colloidal solution, which is freeze-dried to obtain a powder product.

[0010] Furthermore, the concentration of HCl in step 1) is 8.9-9.1 mol / L.

[0011] Furthermore, the mass ratio of Ti3AlC2 and LiF in step 1) is 1:1-1.2:1.

[0012] Furthermore, the amount of ethanolamine used in step 2) is 10-25 ml, the ultrasonic time is 30-45 minutes, and the stirring and dissolving time of adding MnCl2·4H2O is 30-45 minutes.

[0013] The beneficial effects of the present invention are as follows: the present invention uses Ti3AlC2, HCl and LiF to synthesize the two-dimensional material Ti3C2Tx by etching. The MnSe nanomaterial is in situ grown on the MXene nanosheet by the solvothermal method to improve the specific capacitance of the material. Electrode materials with different solvent ratios and different MXene addition amounts are synthesized. When the current density is 1A -1 When the performance is the best, E3 / MnSe@Ti3C2T X-45 exhibits 721F g -1 The high specific capacitance, when the current density increases to 10A -1 When the specific capacitance drops to 373F g -1 The retention rate of the original specific capacitance is 51.7%, which is much higher than that of the unmodified Ti3C2Tx at a current density of 1A g -1 The 72.2F g -1 . BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings:

[0015] Figure 1 Comparison of CV curves of different electrode materials;

[0016] Figure 2 This is a comparison chart of GCD curves of different electrode materials;

[0017] Figure 3 It is a line graph of specific capacitance and rate of different electrode materials at different current densities;

[0018] Specific implementation

[0019] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] Example 1

[0021] Preparation of E5 / MnSe@Ti3C2T X -15 electrode material, the steps are as follows:

[0022] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0023] 2) 15 mg of MXene powder was dispersed in 25 ml of ethanolamine, ultrasonicated at low temperature for 30 min, then 1.5 mmol of MnCl2·4H2O was added and dissolved under magnetic stirring for 45 min, then 1.5 mmol of Se and 5 mmol of NaBH4 were added to the mixture, magnetically stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0024] Example 2

[0025] Preparation of E5 / MnSe@Ti3C2T X -30 electrode material, the steps are as follows:

[0026] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0027] 2) 30 mg of MXene powder was dispersed in 25 ml of ethanolamine, ultrasonicated at low temperature for 30 min, then 1.5 mmol of MnCl2·4H2O was added and dissolved under magnetic stirring for 45 min, then 1.5 mmol of Se and 5 mmol of NaBH4 were added to the mixture, magnetically stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0028] Example 3

[0029] Preparation of E5 / MnSe@Ti3C2T X -45 electrode material, the steps are as follows:

[0030] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0031] 2) 45 mg of MXene powder was dispersed in 25 ml of ethanolamine, ultrasonicated at low temperature for 30 min, then 1.5 mmol of MnCl2·4H2O was added and dissolved under magnetic stirring for 45 min, then 1.5 mmol of Se and 5 mmol of NaBH4 were added to the mixture, magnetically stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0032] Example 4

[0033] Preparation of E5 / MnSe@Ti3C2T X -60 electrode material, the steps are as follows:

[0034] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0035] 2) 60 mg of MXene powder was dispersed in 25 ml of ethanolamine, ultrasonicated at low temperature for 30 min, then 1.5 mmol of MnCl2·4H2O was added and dissolved under magnetic stirring for 45 min, then 1.5 mmol of Se and 5 mmol of NaBH4 were added to the mixture, magnetically stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0036] Example 5

[0037] Preparation of E4 / MnSe@Ti3C2T X -15 electrode material, the steps are as follows:

[0038] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0039] 2) Dissolve 15 mg of MXene powder in 5 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 20 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0040] Example 6

[0041] Preparation of E4 / MnSe@Ti3C2T X -30 electrode material, the steps are as follows:

[0042] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0043] 2) Dissolve 30 mg of MXene powder in 5 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 20 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0044] Example 7

[0045] Preparation of E4 / MnSe@Ti3C2T X -45 electrode material, the steps are as follows:

[0046] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0047] 2) Dissolve 45 mg of MXene powder in 5 ml of deionized water, sonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 20 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0048] Example 8

[0049] Preparation of E4 / MnSe@Ti3C2T X -60 electrode material, the steps are as follows:

[0050] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0051] 2) Dissolve 60 mg of MXene powder in 5 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 20 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0052] Example 9

[0053] Preparation of E3 / MnSe@Ti3C2T X -15 electrode material, the steps are as follows:

[0054] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0055] 2) Dissolve 15 mg of MXene powder in 10 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 15 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0056] Example 10

[0057] Preparation of E3 / MnSe@Ti3C2T X -30 electrode material, the steps are as follows:

[0058] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0059] 2) 30 mg of MXene powder was dissolved in 10 ml of deionized water, and ultrasonicated at low temperature for 30 min. 1.5 mmol MnCl2·4H2O was added to 15 ml of ethanolamine, and then dissolved for 45 min under magnetic stirring. The two solutions were mixed and stirred for 30 min, and then 1.5 mmol Se and 5 mmol NaBH4 were added to the mixture, stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0060] Embodiment 11

[0061] Preparation of E3 / MnSe@Ti3C2T X -45 electrode material, the steps are as follows:

[0062] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0063] 2) Dissolve 45 mg of MXene powder in 10 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 15 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0064] Example 12

[0065] Preparation of E3 / MnSe@Ti3C2T X -60 electrode material, the steps are as follows:

[0066] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0067] 2) Dissolve 60 mg of MXene powder in 10 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 15 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0068] Embodiment 13

[0069] Preparation of E2 / MnSe@Ti3C2T X -15 electrode material, the steps are as follows:

[0070] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0071] 2) Dissolve 15 mg of MXene powder in 15 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 10 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0072] Embodiment 14

[0073] Preparation of E2 / MnSe@Ti3C2T X -30 electrode material, the steps are as follows:

[0074] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0075] 2) 30 mg of MXene powder was dissolved in 15 ml of deionized water, and ultrasonicated at low temperature for 30 min. 1.5 mmol MnCl2·4H2O was added to 10 ml of ethanolamine, and then dissolved for 45 min under magnetic stirring. The two solutions were mixed and stirred for 30 min, and then 1.5 mmol Se and 5 mmol NaBH4 were added to the mixture, stirred for 45 min, and then the mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180 ° C for 12 h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected, washed with deionized water, and freeze-dried to obtain a powder product.

[0076] Embodiment 15

[0077] Preparation of E2 / MnSe@Ti3C2T X -45 electrode material, the steps are as follows:

[0078] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0079] 2) Dissolve 45 mg of MXene powder in 15 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 10 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0080] Example 16

[0081] Preparation of E2 / MnSe@Ti3C2T X -60 electrode material, the steps are as follows:

[0082] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0083] 2) Dissolve 60 mg of MXene powder in 15 ml of deionized water, ultrasonicate at low temperature for 30 min, add 1.5 mmol MnCl2·4H2O to 10 ml of ethanolamine, and then dissolve for 45 min under magnetic stirring. Mix and stir the two solutions for 30 min, then add 1.5 mmol Se and 5 mmol NaBH4 to the mixture, stir for 45 min, and then transfer the mixture to a polytetrafluoroethylene-lined autoclave and heat at 180 ° C for 12 h. After the reaction is completed, wait for the reactor to cool to room temperature, collect the product, wash with deionized water, and freeze-dry to obtain a powder product.

[0084] Comparative Example 1

[0085] Preparation of Ti3C2T X Electrode materials, the steps are as follows:

[0086] 1) Take 2g Ti3AlC2 powder and slowly add it to 40mL 9mol / L HCl (HCl solution is stirred for 5min) and 2g LiF mixed solution, and stir it under magnetic stirring at 35℃ for 24h. Then centrifuge the solution and wash it until the pH reaches neutral. X Dispersed in a certain amount of deionized water, ultrasonic peeling was performed while passing inert gas (argon). X The solution was centrifuged at 3500 rpm for 1 h, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product.

[0087] Test Example 1

[0088] Cyclic voltammetry is a basic electrochemical test method that observes the CV curve at 10mV s -1 The size of the integrated area at the scanning speed, the larger the integrated area, the larger the capacity and the better the performance. We tested the weight specific capacitance performance of the materials obtained in Examples 1-16 and the comparative example respectively. The results are as follows Figure 1 shown.

[0089] from Figure 1 It can be seen that:

[0090] E3 / MnSe@Ti3C2T X -45 is the electrode material with the largest integral area.

[0091] Specifically, at 10mV s -1 At the scan rate, the specific capacitance of the electrode materials reaches:

[0092] E2 / MnSe@Ti3C2TX -60 is 129.58F g -1 ,

[0093] E2 / MnSe@Ti3C2T X -45 is 219.85F g -1 ,

[0094] E2 / MnSe@Ti3C2T X -30 is 218.48F g -1 ,

[0095] E2 / MnSe@Ti3C2T X -15 is 186.96F g -1 .

[0096] E3 / MnSe@Ti3C2T X -60 is 194.88F g -1 ,

[0097] E3 / MnSe@Ti3C2T X -45 is 339.56F g -1 ,

[0098] E3 / MnSe@Ti3C2T X -30 is 251.84F g -1 ,

[0099] E3 / MnSe@Ti3C2T X -15 is 206.78F g -1 .

[0100] E4 / MnSe@Ti3C2T X -60 is 165.17F g -1 ,

[0101] E4 / MnSe@Ti3C2T X -45 is 261.37F g -1 ,

[0102] E4 / MnSe@Ti3C2T X -30 is 270.17F g -1 ,

[0103] E4 / MnSe@Ti3C2T X -15 is 154.45F g -1 .

[0104] E5 / MnSe@Ti3C2T X -60 is 121.27F g -1 ,

[0105] E5 / MnSe@Ti3C2T X -45 is 193.45F g -1 ,

[0106] E5 / MnSe@Ti3C2T X -30 is 214.02F g -1 ,

[0107] E5 / MnSe@Ti3C2T X -15 is 190.42F g -1 .

[0108] Ti3C2T X 73.97F g -1 .

[0109] In summary, the specific capacitance of all synthesized electrode materials is higher than that of unmodified Ti3C2T X Among them, E3 / MnSe@Ti3C2T has the best performance X -45 of 339.56F g -1 .

[0110] Test Example 2

[0111] The electrode material is tested by constant current charge and discharge to evaluate the performance and energy storage mechanism of the electrochemical electrode material. -1 The longer the charge and discharge time under the current density, the greater the capacity and the better the performance. We tested the weight specific capacitance performance of the materials obtained in Examples 1-16 and the comparative example respectively. The results are as follows Figure 2 shown.

[0112] from Figure 2 It can be seen that:

[0113] E3 / MnSe@Ti3C2T X -45 is the electrode material with the longest charge and discharge time.

[0114] Specifically, in 2Ag -1 At current densities of , the specific capacitances of the electrode materials are:

[0115] E2 / MnSe@Ti3C2T X -60 is 207.61F g -1 ,

[0116] E2 / MnSe@Ti3C2T X -45 is 266.93F g -1 ,

[0117] E2 / MnSe@Ti3C2T X -30 is 301.01F g -1 ,

[0118] E2 / MnSe@Ti3C2T X -15 is 263.61F g -1 .

[0119] E3 / MnSe@Ti3C2T X -60 is 290.38F g -1 ,

[0120] E3 / MnSe@Ti3C2T X -45 is 601.98F g -1 ,

[0121] E3 / MnSe@Ti3C2T X -30 is 452.78F g -1 ,

[0122] E3 / MnSe@Ti3C2T X -15 is 392.72F g -1 .

[0123] E4 / MnSe@Ti3C2T X -60 is 199.13F g -1 ,

[0124] E4 / MnSe@Ti3C2T X -45 is 423.66F g -1 ,

[0125] E4 / MnSe@Ti3C2T X -30 is 374.32F g -1 ,

[0126] E4 / MnSe@Ti3C2T X -15 is 215.28F g -1 .

[0127] E5 / MnSe@Ti3C2T X -60 is 130.25F g -1 ,

[0128] E5 / MnSe@Ti3C2T X -45 is 236.01F g -1 ,

[0129] E5 / MnSe@Ti3C2T X -30 is 240.58F g-1 ,

[0130] E5 / MnSe@Ti3C2T X -15 is 207.03F g -1 .

[0131] Ti3C2T X 72.02F g -1 .

[0132] In summary, the specific capacitance of all synthesized electrode materials is higher than that of unmodified Ti3C2T X Among them, E3 / MnSe@Ti3C2T has the best performance X -45 of 601.98F g -1 .

[0133] Test Example 3

[0134] The specific capacitance of the electrode material at different current densities was calculated by constant current charge and discharge test and a line graph was drawn to evaluate its specific capacitance and rate performance. We tested the weight specific capacitance and rate performance of the materials obtained in Examples 1-16 and the comparative example respectively. The results are shown in Figure 3 shown.

[0135] from Figure 3 It can be seen that the best comprehensive performance is E3 / MnSe@Ti3C2T X -45 electrode material.

[0136] Specifically, E2 / MnSe@Ti3C2T X -60 in 1Ag -1 The specific capacitance is 281.16 F g -1 , the current density is 10Ag -1 The specific capacitance is 87.06 F g -1 , the rate performance is 31.0%;

[0137] E2 / MnSe@Ti3C2T X -45 in 1Ag -1 The specific capacitance is 305.28 F g -1 , the current density is 10Ag -1 The specific capacitance is 159.68 F g -1 , the rate performance is 52.3%;

[0138] E2 / MnSe@Ti3C2T X -30 in 1Ag -1 The specific capacitance is 348.48 F g -1 , the current density is 10A g -1The specific capacitance is 182.52 F g -1 , the rate performance is 52.4%;

[0139] E2 / MnSe@Ti3C2T X -15 in 1Ag -1 The specific capacitance is 333.33 F g -1 , the current density is 10A g -1 The specific capacitance is 153.27 F g -1 , the rate performance is 46.0%;

[0140] E3 / MnSe@Ti3C2T X -60 in 1Ag -1 The specific capacitance is 320.51 F g -1 , the current density is 10A g -1 The specific capacitance is 182.22 F g -1 , the rate performance is 56.9%;

[0141] E3 / MnSe@Ti3C2T X -45 in 1Ag -1 The specific capacitance is 721.39 F g -1 , the current density is 10Ag -1 The specific capacitance is 373.15 F g -1 , the rate performance is 51.7%;

[0142] E3 / MnSe@Ti3C2T X -30 in 1Ag -1 The specific capacitance is 551.03 F g -1 , the current density is 10Ag -1 The specific capacitance is 280.85 F g -1 , the rate performance is 51.0%;

[0143] E3 / MnSe@Ti3C2T X -15 in 1Ag -1 The specific capacitance is 474.93 F g -1 , the current density is 10Ag -1 The specific capacitance is 217.75 F g -1 , the rate performance is 45.8%.

[0144] E4 / MnSe@Ti3C2T X -60 in 1Ag -1 The specific capacitance is 222.20 F g -1 , the current density is 10Ag -1 The specific capacitance is 124.06 F g-1 , the rate performance is 55.8%;

[0145] E4 / MnSe@Ti3C2T X -45 in 1Ag -1 The specific capacitance is 527.81 F g -1 , the current density is 10Ag -1 The specific capacitance is 231.20 F g -1 , the rate performance is 43.8%;

[0146] E4 / MnSe@Ti3C2T X -30 in 1Ag -1 The specific capacitance is 439.28 F g -1 , the current density is 10Ag -1 The specific capacitance is 240.55 F g -1 , the rate performance is 54.8%;

[0147] E4 / MnSe@Ti3C2T X -15 in 1Ag -1 The specific capacitance is 271.42 F g -1 , the current density is 10Ag -1 The specific capacitance is 114.68 F g -1 , the rate performance is 42.3%.

[0148] E5 / MnSe@Ti3C2T X -60 in 1Ag -1 The specific capacitance is 174.23 F g -1 , the current density is 10Ag -1 The specific capacitance is 42.19 F g -1 , the rate performance is 24.2%;

[0149] E5 / MnSe@Ti3C2T X -45 in 1Ag -1 The specific capacitance is 296.12 F g -1 , the current density is 10Ag -1 The specific capacitance is 87.09 F g -1 , the rate performance is 29.4%;

[0150] E5 / MnSe@Ti3C2T X -30 at 1A g -1 The specific capacitance is 288.69 F g -1 , the current density is 10A g -1 The specific capacitance is 123.52 F g -1, the rate performance is 42.8%;

[0151] E5 / MnSe@Ti3C2T X -15 at 1A g -1 The specific capacitance is 251.32 F g -1 , the current density is 10A g -1 The specific capacitance is 115.15 F g -1 , the rate performance is 45.8%.

[0152] In summary, except for E5 / MnSe@Ti3C2T X -60 at 10A g -1 The specific capacitance is 42.19 F g -1 Lower than Ti3C2T X Except for Ti3C2T, the specific capacitance of all other materials is higher than that of Ti3C2T X 72.20F g -1 , and at 10A g -1 71.01F g -1 .

[0153] In summary, E3 / MnSe@Ti3C2T has the best weight-to-capacitance performance and rate performance. X -45, E3 / MnSe@Ti3C2T X -30, E3 / MnSe@Ti3C2T X -15, E4 / MnSe@Ti3C2T X -45, E4 / MnSe@Ti3C2T X -30, the best weight-to-capacitance performance and rate performance are E3 / MnSe@Ti3C2T X -45.

[0154] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing an electrode material based on MXene, characterized in that: The preparation steps are as follows: 1) A two-dimensional material Ti3C2Tx, called MXene, is synthesized by etching aluminum titanium carbide Ti3AlC2, hydrochloric acid HCl, and lithium fluoride LiF. The MXene is a nanosheet with a thickness of 1-2 nm and a lateral size of 100-600 nm; 2) dispersing the MXene prepared in step 1) in ethanolamine or water / ethanolamine solution, sonicating at low temperature, adding manganese chloride tetrahydrate MnCl2·4H2O to dissolve, then adding selenium powder Se and sodium borohydride NaBH4, stirring, heating at 175°C to 185°C for 11 to 13 hours, cooling to room temperature after the reaction, collecting the product, washing with deionized water, and freeze-drying to obtain a powder product; The feed mass of the MXene is 15-60 mg, the molar ratio of Se and MnCl2·4H2O is 1:1, and the volume of ethanolamine and water is 5:0-2:3; Step 1) is specifically as follows: dissolving Ti3AlC2 powder in a mixed solution of HCl and LiF, stirring and reacting at 30°C to 40°C for 23 to 25 hours, then centrifuging the solution and washing until the pH reaches neutral, and then centrifuging to obtain Ti3C2T X , dispersed in deionized water, and ultrasonically exfoliated while passing inert gas. The Ti3C2T X The solution was centrifuged at 3000 rpm to 4000 rpm for 1 hour to 1.5 hours, and the supernatant collected was Ti3C2T X The nanosheet colloidal solution was freeze-dried to obtain a powder product; The concentration of HCl in step 1) is 8.9-9.1 mol / L.

2. The method for preparing a MXene-based electrode material according to claim 1, characterized in that: The feed mass of MXene is 30-45 mg, and the volume ratio of ethanolamine to water is 4:1-3:

2.

3. The method for preparing a MXene-based electrode material according to claim 1, characterized in that: The feed mass of MXene was 45 mg, and the volume ratio of ethanolamine to water was 3:

2.

4. The method for preparing a MXene-based electrode material according to claim 1, characterized in that: The mass ratio of Ti3AlC2 and LiF in step 1) is 1:1-1.2:

1.

5. The method for preparing a MXene-based electrode material according to claim 1, characterized in that: The amount of ethanolamine used in step 2) is 10-25 ml, the ultrasonic time is 30-45 minutes, and the stirring and dissolving time of adding MnCl2·4H2O is 30-45 minutes.

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